2013-09-16 14:22:23

by Georgi Djakov

[permalink] [raw]
Subject: [PATCH v5] mmc: sdhci-msm: Add support for MSM chipsets

This platform driver adds the support of Secure Digital Host Controller
Interface compliant controller found in Qualcomm MSM chipsets.

CC: Asutosh Das <[email protected]>
CC: Venkat Gopalakrishnan <[email protected]>
CC: Sahitya Tummala <[email protected]>
CC: Subhash Jadavani <[email protected]>
Signed-off-by: Georgi Djakov <[email protected]>
---
Changes from v4:
- Simplified sdhci_msm_vreg_disable() and sdhci_msm_set_vdd_io_vol()
- Use devm_ioremap_resource() instead of devm_ioremap()
- Converted IS_ERR_OR_NULL to IS_ERR
- Disable regulators in sdhci_msm_remove()
- Check for DT node at the beginning in sdhci_msm_probe()
- Removed more redundant code
- Changes in some error messages
- Minor fixes

Changes from v3:
- Allocate memory for all required structs at once
- Added termination entry in sdhci_msm_dt_match[]
- Fixed a missing sdhci_pltfm_free() in probe()
- Removed redundant of_match_ptr
- Removed the unneeded function sdhci_msm_vreg_reset()

Changes from v2:
- Added DT bindings for clocks
- Moved voltage regulators data to platform data
- Removed unneeded includes
- Removed obsolete and wrapper functions
- Removed error checking where unnecessary
- Removed redundant _clk suffix from clock names
- Just return instead of goto where possible
- Minor fixes

Changes from v1:
- GPIO references are replaced by pinctrl
- DT parsing is done mostly by mmc_of_parse()
- Use of_match_device() for DT matching
- A few minor changes

.../devicetree/bindings/mmc/sdhci-msm.txt | 71 +++
drivers/mmc/host/Kconfig | 13 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/sdhci-msm.c | 627 ++++++++++++++++++++
4 files changed, 712 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mmc/sdhci-msm.txt
create mode 100644 drivers/mmc/host/sdhci-msm.c

diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
new file mode 100644
index 0000000..ee112da
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
@@ -0,0 +1,71 @@
+* Qualcomm SDHCI controller (sdhci-msm)
+
+This file documents differences between the core properties in mmc.txt
+and the properties used by the sdhci-msm driver.
+
+Required properties:
+- compatible: should be "qcom,sdhci-msm"
+- reg: should contain SDHC, SD Core register map
+- reg-names: indicates various resources passed to driver (via reg proptery) by name
+ "reg-names" examples are "hc_mem" and "core_mem"
+- interrupts: should contain SDHC interrupts
+- interrupt-names: indicates interrupts passed to driver (via interrupts property) by name
+ "interrupt-names" examples are "hc_irq" and "pwr_irq"
+- <supply-name>-supply: phandle to the regulator device tree node
+ "supply-name" examples are "vdd" and "vdd-io"
+- pinctrl-names: Should contain only one value - "default".
+- pinctrl-0: Should specify pin control groups used for this controller.
+- clocks: phandles to clock instances of the device tree nodes
+- clock-names:
+ iface: Main peripheral bus clock (PCLK/HCLK - AHB Bus clock) (required)
+ core: SDC MMC clock (MCLK) (required)
+ bus: SDCC bus voter clock (optional)
+
+Optional properties:
+- qcom,bus-speed-mode - specifies supported bus speed modes by host
+ The supported bus speed modes are :
+ "HS200_1p8v" - indicates that host can support HS200 at 1.8v
+ "HS200_1p2v" - indicates that host can support HS200 at 1.2v
+ "DDR_1p8v" - indicates that host can support DDR mode at 1.8v
+ "DDR_1p2v" - indicates that host can support DDR mode at 1.2v
+
+In the following, <supply> can be vdd (flash core voltage) or vdd-io (I/O voltage).
+- qcom,<supply>-always-on - specifies whether supply should be kept "on" always.
+- qcom,<supply>-lpm-sup - specifies whether supply can be kept in low power mode (lpm).
+- qcom,<supply>-voltage-level - specifies voltage levels for supply. Should be
+specified in pairs (min, max), units uV.
+- qcom,<supply>-current-level - specifies load levels for supply in lpm or high power mode
+ (hpm). Should be specified in pairs (lpm, hpm), units uA.
+
+Example:
+
+ aliases {
+ sdhc1 = &sdhc_1;
+ };
+
+ sdhc_1: qcom,sdhc@f9824900 {
+ compatible = "qcom,sdhci-msm";
+ reg = <0xf9824900 0x11c>, <0xf9824000 0x800>;
+ reg-names = "hc_mem", "core_mem";
+ interrupts = <0 123 0>, <0 138 0>;
+ interrupt-names = "hc_irq", "pwr_irq";
+ bus-width = <4>;
+ non-removable;
+
+ vdd-supply = <&pm8941_l21>;
+ vdd-io-supply = <&pm8941_l13>;
+ qcom,vdd-voltage-level = <2950000 2950000>;
+ qcom,vdd-current-level = <9000 800000>;
+ qcom,vdd-io-always-on;
+ qcom,vdd-io-lpm-sup;
+ qcom,vdd-io-voltage-level = <1800000 2950000>;
+ qcom,vdd-io-current-level = <6 22000>;
+ qcom,bus-speed-mode = "HS200_1p8v", "DDR_1p8v";
+
+ pinctrl-names = "default";
+ pinctrl-0 = <&sdc1_clk &sdc1_cmd &sdc1_data>;
+
+ clocks = <&iface>, <&core>, <&bus>;
+ clock-names = "iface", "core", "bus";
+
+ };
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 7fc5099..e8da488 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -322,6 +322,19 @@ config MMC_ATMELMCI

If unsure, say N.

+config MMC_SDHCI_MSM
+ tristate "Qualcomm SDHCI Controller Support"
+ depends on ARCH_MSM
+ depends on MMC_SDHCI_PLTFM
+ help
+ This selects the Secure Digital Host Controller Interface (SDHCI)
+ support present in MSM SOCs from Qualcomm. The controller
+ supports SD/MMC/SDIO devices.
+
+ If you have a controller with this interface, say Y or M here.
+
+ If unsure, say N.
+
config MMC_MSM
tristate "Qualcomm SDCC Controller Support"
depends on MMC && ARCH_MSM
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index c41d0c3..5faed14 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_MMC_SDHCI_OF_ESDHC) += sdhci-of-esdhc.o
obj-$(CONFIG_MMC_SDHCI_OF_HLWD) += sdhci-of-hlwd.o
obj-$(CONFIG_MMC_SDHCI_BCM_KONA) += sdhci-bcm-kona.o
obj-$(CONFIG_MMC_SDHCI_BCM2835) += sdhci-bcm2835.o
+obj-$(CONFIG_MMC_SDHCI_MSM) += sdhci-msm.o

ifeq ($(CONFIG_CB710_DEBUG),y)
CFLAGS-cb710-mmc += -DDEBUG
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
new file mode 100644
index 0000000..c746a9b
--- /dev/null
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -0,0 +1,627 @@
+/*
+ * drivers/mmc/host/sdhci-msm.c - Qualcomm MSM SDHCI Platform
+ * driver source file
+ *
+ * Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/regulator/consumer.h>
+
+#include "sdhci-pltfm.h"
+
+#define CORE_HC_MODE 0x78
+#define HC_MODE_EN 0x1
+
+#define CORE_POWER 0x0
+#define CORE_SW_RST (1 << 7)
+
+#define CORE_PWRCTL_STATUS 0xdc
+#define CORE_PWRCTL_MASK 0xe0
+#define CORE_PWRCTL_CLEAR 0xe4
+#define CORE_PWRCTL_CTL 0xe8
+
+#define CORE_PWRCTL_BUS_OFF 0x01
+#define CORE_PWRCTL_BUS_ON (1 << 1)
+#define CORE_PWRCTL_IO_LOW (1 << 2)
+#define CORE_PWRCTL_IO_HIGH (1 << 3)
+
+#define CORE_PWRCTL_BUS_SUCCESS 0x01
+#define CORE_PWRCTL_BUS_FAIL (1 << 1)
+#define CORE_PWRCTL_IO_SUCCESS (1 << 2)
+#define CORE_PWRCTL_IO_FAIL (1 << 3)
+
+#define INT_MASK 0xf
+
+/* This structure keeps information per regulator */
+struct sdhci_msm_reg_data {
+ /* voltage regulator handle */
+ struct regulator *reg;
+ /* regulator name */
+ const char *name;
+ /* voltage level to be set */
+ u32 low_vol_level;
+ u32 high_vol_level;
+ /* Load values for low power and high power mode */
+ u32 lpm_uA;
+ u32 hpm_uA;
+
+ /* is this regulator needs to be always on? */
+ bool is_always_on;
+ /* is low power mode setting required for this regulator? */
+ bool lpm_sup;
+};
+
+struct sdhci_msm_pltfm_data {
+ u32 caps; /* Supported UHS-I Modes */
+ u32 caps2; /* More capabilities */
+ struct sdhci_msm_reg_data vdd_data; /* VDD/VCC regulator info */
+ struct sdhci_msm_reg_data vdd_io_data; /* VDD IO regulator info */
+};
+
+struct sdhci_msm_host {
+ struct platform_device *pdev;
+ void __iomem *core_mem; /* MSM SDCC mapped address */
+ int pwr_irq; /* power irq */
+ struct clk *clk; /* main SD/MMC bus clock */
+ struct clk *pclk; /* SDHC peripheral bus clock */
+ struct clk *bus_clk; /* SDHC bus voter clock */
+ struct sdhci_msm_pltfm_data pdata;
+ struct mmc_host *mmc;
+ struct sdhci_pltfm_data sdhci_msm_pdata;
+};
+
+enum vdd_io_level {
+ /* set vdd_io_data->low_vol_level */
+ VDD_IO_LOW,
+ /* set vdd_io_data->high_vol_level */
+ VDD_IO_HIGH,
+ /*
+ * set whatever there in voltage_level (third argument) of
+ * sdhci_msm_set_vdd_io_vol() function.
+ */
+ VDD_IO_SET_LEVEL,
+};
+
+#define MAX_PROP_SIZE 32
+static int sdhci_msm_dt_parse_vreg_info(struct device *dev,
+ struct sdhci_msm_reg_data *vreg,
+ const char *vreg_name)
+{
+ int len, ret = 0;
+ const __be32 *prop;
+ char prop_name[MAX_PROP_SIZE];
+ struct device_node *np = dev->of_node;
+
+ snprintf(prop_name, MAX_PROP_SIZE, "%s-supply", vreg_name);
+ if (!of_parse_phandle(np, prop_name, 0)) {
+ dev_info(dev, "No vreg data found for %s\n", vreg_name);
+ return -EINVAL;
+ }
+
+ vreg->name = vreg_name;
+
+ snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-always-on", vreg_name);
+ if (of_get_property(np, prop_name, NULL))
+ vreg->is_always_on = true;
+
+ snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-lpm-sup", vreg_name);
+ if (of_get_property(np, prop_name, NULL))
+ vreg->lpm_sup = true;
+
+ snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-voltage-level", vreg_name);
+ prop = of_get_property(np, prop_name, &len);
+ if (!prop || (len != (2 * sizeof(__be32)))) {
+ dev_warn(dev, "%s %s property\n",
+ prop ? "invalid format" : "no", prop_name);
+ } else {
+ vreg->low_vol_level = be32_to_cpup(&prop[0]);
+ vreg->high_vol_level = be32_to_cpup(&prop[1]);
+ }
+
+ snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-current-level", vreg_name);
+ prop = of_get_property(np, prop_name, &len);
+ if (!prop || (len != (2 * sizeof(__be32)))) {
+ dev_warn(dev, "%s %s property\n",
+ prop ? "invalid format" : "no", prop_name);
+ } else {
+ vreg->lpm_uA = be32_to_cpup(&prop[0]);
+ vreg->hpm_uA = be32_to_cpup(&prop[1]);
+ }
+
+ dev_dbg(dev, "%s: %s%svol=[%d %d]uV, curr=[%d %d]uA\n",
+ vreg->name, vreg->is_always_on ? "always_on, " : "",
+ vreg->lpm_sup ? "lpm_sup, " : "", vreg->low_vol_level,
+ vreg->high_vol_level, vreg->lpm_uA, vreg->hpm_uA);
+
+ return ret;
+}
+
+/* Parse platform data */
+static int sdhci_msm_populate_pdata(struct device *dev,
+ struct sdhci_msm_pltfm_data *pdata)
+{
+ struct device_node *np = dev->of_node;
+ int len, i;
+
+ if (sdhci_msm_dt_parse_vreg_info(dev, &pdata->vdd_data, "vdd")) {
+ dev_err(dev, "failed parsing vdd data\n");
+ return -EINVAL;
+ }
+ if (sdhci_msm_dt_parse_vreg_info(dev, &pdata->vdd_io_data, "vdd-io")) {
+ dev_err(dev, "failed parsing vdd-io data\n");
+ return -EINVAL;
+ }
+
+ len = of_property_count_strings(np, "qcom,bus-speed-mode");
+
+ for (i = 0; i < len; i++) {
+ const char *name = NULL;
+
+ of_property_read_string_index(np,
+ "qcom,bus-speed-mode", i, &name);
+ if (!name)
+ continue;
+
+ if (!strncmp(name, "HS200_1p8v", sizeof("HS200_1p8v")))
+ pdata->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
+ else if (!strncmp(name, "HS200_1p2v", sizeof("HS200_1p2v")))
+ pdata->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
+ else if (!strncmp(name, "DDR_1p8v", sizeof("DDR_1p8v")))
+ pdata->caps |= MMC_CAP_1_8V_DDR | MMC_CAP_UHS_DDR50;
+ else if (!strncmp(name, "DDR_1p2v", sizeof("DDR_1p2v")))
+ pdata->caps |= MMC_CAP_1_2V_DDR | MMC_CAP_UHS_DDR50;
+ }
+
+ return 0;
+}
+
+/* Regulator utility functions */
+static int sdhci_msm_vreg_init_reg(struct device *dev,
+ struct sdhci_msm_reg_data *vreg)
+{
+ int ret = 0;
+ /* Get the regulator handle */
+ vreg->reg = devm_regulator_get(dev, vreg->name);
+ if (IS_ERR(vreg->reg)) {
+ ret = PTR_ERR(vreg->reg);
+ dev_err(dev, "devm_regulator_get(%s) failed. ret=%d\n",
+ vreg->name, ret);
+ return ret;
+ }
+
+ /* sanity check */
+ if (!vreg->high_vol_level || !vreg->hpm_uA) {
+ dev_err(dev, "%s invalid constraints specified\n", vreg->name);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int sdhci_msm_vreg_enable(struct sdhci_msm_reg_data *vreg)
+{
+ int ret = 0;
+
+ /* Put regulator in HPM (high power mode) */
+ ret = regulator_set_optimum_mode(vreg->reg, vreg->hpm_uA);
+ if (ret < 0) {
+ pr_err("regulator_set_optimum_mode(%s,uA_load=%d) fail (%d)\n",
+ vreg->name, vreg->hpm_uA, ret);
+ return ret;
+ }
+
+ if (!regulator_is_enabled(vreg->reg)) {
+ /* Set voltage level */
+ ret = regulator_set_voltage(vreg->reg, vreg->high_vol_level,
+ vreg->high_vol_level);
+ if (ret)
+ return ret;
+ }
+
+ ret = regulator_enable(vreg->reg);
+ if (ret) {
+ pr_err("regulator_enable(%s) fail (%d)\n", vreg->name, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int sdhci_msm_vreg_disable(struct sdhci_msm_reg_data *vreg)
+{
+ int ret = 0;
+
+ if (!regulator_is_enabled(vreg->reg))
+ return 0;
+
+ /* Never disable regulator marked as always_on */
+ if (vreg->is_always_on) {
+ if (vreg->lpm_sup) {
+ /* Put always_on regulator in LPM (low power mode) */
+ ret = regulator_set_optimum_mode(vreg->reg,
+ vreg->lpm_uA);
+ if (ret < 0)
+ return ret;
+ }
+ } else {
+ ret = regulator_disable(vreg->reg);
+ if (ret) {
+ pr_err("regulator_disable(%s) fail (%d)\n",
+ vreg->name, ret);
+ return ret;
+ }
+
+ ret = regulator_set_optimum_mode(vreg->reg, 0);
+ if (ret < 0)
+ return ret;
+
+ /* Set min. voltage level to 0 */
+ ret = regulator_set_voltage(vreg->reg, 0, vreg->high_vol_level);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int sdhci_msm_setup_vreg(struct sdhci_msm_pltfm_data *pdata,
+ bool enable, bool is_init)
+{
+ int ret = 0, i;
+ struct sdhci_msm_reg_data *vreg_table[2];
+
+ vreg_table[0] = &pdata->vdd_data;
+ vreg_table[1] = &pdata->vdd_io_data;
+
+ for (i = 0; i < ARRAY_SIZE(vreg_table); i++) {
+ if (vreg_table[i]) {
+ if (enable)
+ ret = sdhci_msm_vreg_enable(vreg_table[i]);
+ else
+ ret = sdhci_msm_vreg_disable(vreg_table[i]);
+ if (ret)
+ return ret;
+ }
+ }
+ return 0;
+}
+
+/* This init function should be called only once for each SDHC slot */
+static int sdhci_msm_vreg_init(struct device *dev,
+ struct sdhci_msm_pltfm_data *pdata)
+{
+ struct sdhci_msm_reg_data *curr_vdd_reg = &pdata->vdd_data;
+ struct sdhci_msm_reg_data *curr_vdd_io_reg = &pdata->vdd_io_data;
+ int ret = 0;
+
+ ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_reg);
+ if (ret)
+ return ret;
+
+ ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_io_reg);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int sdhci_msm_set_vdd_io_vol(struct sdhci_msm_pltfm_data *pdata,
+ enum vdd_io_level level,
+ unsigned int voltage_level)
+{
+ int set_level;
+ struct sdhci_msm_reg_data *vdd_io_reg = &pdata->vdd_io_data;
+
+ if (!regulator_is_enabled(vdd_io_reg->reg))
+ return 0;
+
+ switch (level) {
+ case VDD_IO_LOW:
+ set_level = vdd_io_reg->low_vol_level;
+ break;
+ case VDD_IO_HIGH:
+ set_level = vdd_io_reg->high_vol_level;
+ break;
+ case VDD_IO_SET_LEVEL:
+ set_level = voltage_level;
+ break;
+ default:
+ pr_err("invalid vdd_io level = %d", level);
+ return -EINVAL;
+ }
+ return regulator_set_voltage(vdd_io_reg->reg, set_level, set_level);
+}
+
+static irqreturn_t sdhci_msm_pwr_irq(int irq, void *data)
+{
+ struct sdhci_msm_host *msm_host = (struct sdhci_msm_host *)data;
+ u8 irq_status = 0;
+ u8 irq_ack = 0;
+ int ret = 0;
+
+ irq_status = readb_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);
+ pr_debug("%s: Received IRQ(%d), status=0x%x\n",
+ mmc_hostname(msm_host->mmc), irq, irq_status);
+
+ /* Clear the interrupt */
+ writeb_relaxed(irq_status, (msm_host->core_mem + CORE_PWRCTL_CLEAR));
+ /*
+ * SDHC has core_mem and hc_mem device memory and these memory
+ * addresses do not fall within 1KB region. Hence, any update to
+ * core_mem address space would require an mb() to ensure this gets
+ * completed before its next update to registers within hc_mem.
+ */
+ mb();
+
+ /* Handle BUS ON/OFF */
+ if (irq_status & (CORE_PWRCTL_BUS_ON | CORE_PWRCTL_BUS_OFF)) {
+ bool flag = (irq_status & CORE_PWRCTL_BUS_ON) ? 1 : 0;
+ ret = sdhci_msm_setup_vreg(&msm_host->pdata, flag, false);
+ if (ret)
+ irq_ack |= CORE_PWRCTL_BUS_FAIL;
+ else
+ irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
+ }
+ /* Handle IO LOW/HIGH */
+ if (irq_status & (CORE_PWRCTL_IO_LOW | CORE_PWRCTL_IO_HIGH)) {
+ /* Switch voltage */
+ int io_status = (irq_status & CORE_PWRCTL_IO_LOW) ?
+ VDD_IO_LOW : VDD_IO_HIGH;
+ ret = sdhci_msm_set_vdd_io_vol(&msm_host->pdata, io_status, 0);
+ if (ret)
+ irq_ack |= CORE_PWRCTL_IO_FAIL;
+ else
+ irq_ack |= CORE_PWRCTL_IO_SUCCESS;
+ }
+
+ /* ACK status to the core */
+ writeb_relaxed(irq_ack, (msm_host->core_mem + CORE_PWRCTL_CTL));
+ /*
+ * SDHC has core_mem and hc_mem device memory and these memory
+ * addresses do not fall within 1KB region. Hence, any update to
+ * core_mem address space would require an mb() to ensure this gets
+ * completed before its next update to registers within hc_mem.
+ */
+ mb();
+
+ pr_debug("%s: Handled IRQ(%d), ret=%d, ack=0x%x\n",
+ mmc_hostname(msm_host->mmc), irq, ret, irq_ack);
+ return IRQ_HANDLED;
+}
+
+/* This function returns the max. current supported by VDD rail in mA */
+static u32 sdhci_msm_get_vdd_max_current(struct sdhci_msm_host *host)
+{
+ return host->pdata.vdd_data.hpm_uA / 1000;
+}
+
+static const struct of_device_id sdhci_msm_dt_match[] = {
+ {.compatible = "qcom,sdhci-msm"},
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, sdhci_msm_dt_match);
+
+static int sdhci_msm_probe(struct platform_device *pdev)
+{
+ struct sdhci_host *host;
+ struct sdhci_pltfm_host *pltfm_host;
+ struct sdhci_msm_host *msm_host;
+ struct resource *core_memres = NULL;
+ int ret = 0, dead = 0;
+ struct pinctrl *pinctrl;
+
+ if (!pdev->dev.of_node) {
+ dev_err(&pdev->dev, "No device tree data\n");
+ return -ENOENT;
+ }
+
+ msm_host = devm_kzalloc(&pdev->dev, sizeof(*msm_host), GFP_KERNEL);
+ if (!msm_host)
+ return -ENOMEM;
+
+ host = sdhci_pltfm_init(pdev, &msm_host->sdhci_msm_pdata, 0);
+ if (IS_ERR(host)) {
+ dev_err(mmc_dev(host->mmc), "sdhci_pltfm_init error\n");
+ return PTR_ERR(host);
+ }
+
+ pltfm_host = sdhci_priv(host);
+ pltfm_host->priv = msm_host;
+ msm_host->mmc = host->mmc;
+ msm_host->pdev = pdev;
+
+ ret = mmc_of_parse(host->mmc);
+ if (ret) {
+ dev_err(&pdev->dev, "failed parsing mmc device tree\n");
+ goto pltfm_free;
+ }
+
+ /* Extract platform data */
+ ret = sdhci_msm_populate_pdata(&pdev->dev, &msm_host->pdata);
+ if (ret) {
+ dev_err(&pdev->dev, "DT parsing error\n");
+ goto pltfm_free;
+ }
+
+ /* Setup pins */
+ pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
+ if (IS_ERR(pinctrl))
+ dev_warn(&pdev->dev, "pins are not configured by the driver\n");
+
+ /* Setup SDCC bus voter clock. */
+ msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus");
+ if (!IS_ERR(msm_host->bus_clk)) {
+ /* Vote for max. clk rate for max. performance */
+ ret = clk_set_rate(msm_host->bus_clk, INT_MAX);
+ if (ret)
+ goto pltfm_free;
+ ret = clk_prepare_enable(msm_host->bus_clk);
+ if (ret)
+ goto pltfm_free;
+ }
+
+ /* Setup main peripheral bus clock */
+ msm_host->pclk = devm_clk_get(&pdev->dev, "iface");
+ if (!IS_ERR(msm_host->pclk)) {
+ ret = clk_prepare_enable(msm_host->pclk);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Main peripheral clock setup failed (%d)\n",
+ ret);
+ goto bus_clk_disable;
+ }
+ }
+
+ /* Setup SDC MMC clock */
+ msm_host->clk = devm_clk_get(&pdev->dev, "core");
+ if (IS_ERR(msm_host->clk)) {
+ ret = PTR_ERR(msm_host->clk);
+ dev_err(&pdev->dev, "SDC MMC clock setup failed (%d)\n", ret);
+ goto pclk_disable;
+ }
+
+ ret = clk_prepare_enable(msm_host->clk);
+ if (ret)
+ goto pclk_disable;
+
+ /* Setup regulators */
+ ret = sdhci_msm_vreg_init(&pdev->dev, &msm_host->pdata);
+ if (ret) {
+ dev_err(&pdev->dev, "Regulator setup failed (%d)\n", ret);
+ goto clk_disable;
+ }
+
+ /* Reset the core and Enable SDHC mode */
+ core_memres = platform_get_resource_byname(pdev,
+ IORESOURCE_MEM, "core_mem");
+ msm_host->core_mem = devm_ioremap_resource(&pdev->dev, core_memres);
+
+ if (IS_ERR(msm_host->core_mem)) {
+ dev_err(&pdev->dev, "Failed to remap registers\n");
+ ret = PTR_ERR(msm_host->core_mem);
+ goto vreg_disable;
+ }
+
+ /* Set SW_RST bit in POWER register (Offset 0x0) */
+ writel_relaxed(CORE_SW_RST, msm_host->core_mem + CORE_POWER);
+ /* Set HC_MODE_EN bit in HC_MODE register */
+ writel_relaxed(HC_MODE_EN, (msm_host->core_mem + CORE_HC_MODE));
+
+ /*
+ * Following are the deviations from SDHC spec v3.0 -
+ * 1. Card detection is handled using separate GPIO.
+ * 2. Bus power control is handled by interacting with PMIC.
+ */
+ host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
+
+ /* Setup PWRCTL irq */
+ msm_host->pwr_irq = platform_get_irq_byname(pdev, "pwr_irq");
+ if (msm_host->pwr_irq < 0) {
+ dev_err(&pdev->dev, "Failed to get pwr_irq by name (%d)\n",
+ msm_host->pwr_irq);
+ goto vreg_disable;
+ }
+ ret = devm_request_threaded_irq(&pdev->dev, msm_host->pwr_irq, NULL,
+ sdhci_msm_pwr_irq, IRQF_ONESHOT,
+ dev_name(&pdev->dev), host);
+ if (ret) {
+ dev_err(&pdev->dev, "Request threaded irq(%d) failed (%d)\n",
+ msm_host->pwr_irq, ret);
+ goto vreg_disable;
+ }
+
+ /* Enable pwr irq interrupts */
+ writel_relaxed(INT_MASK, (msm_host->core_mem + CORE_PWRCTL_MASK));
+
+ /* Set host capabilities */
+ msm_host->mmc->caps |= msm_host->pdata.caps;
+ msm_host->mmc->caps2 |= msm_host->pdata.caps2;
+
+ ret = sdhci_add_host(host);
+ if (ret) {
+ dev_err(&pdev->dev, "Add host failed (%d)\n", ret);
+ goto vreg_disable;
+ }
+
+ /* Set core clk rate */
+ ret = clk_set_rate(msm_host->clk, host->max_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "MClk rate set failed (%d)\n", ret);
+ goto remove_host;
+ }
+
+ host->mmc->max_current_180 = host->mmc->max_current_300 =
+ host->mmc->max_current_330 = sdhci_msm_get_vdd_max_current(msm_host);
+
+ /* Successful initialization */
+ return 0;
+
+remove_host:
+ dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
+ sdhci_remove_host(host, dead);
+vreg_disable:
+ if (!IS_ERR(msm_host->pdata.vdd_data.reg))
+ sdhci_msm_vreg_disable(&msm_host->pdata.vdd_data);
+ if (!IS_ERR(msm_host->pdata.vdd_io_data.reg))
+ sdhci_msm_vreg_disable(&msm_host->pdata.vdd_io_data);
+clk_disable:
+ if (!IS_ERR(msm_host->clk))
+ clk_disable_unprepare(msm_host->clk);
+pclk_disable:
+ if (!IS_ERR(msm_host->pclk))
+ clk_disable_unprepare(msm_host->pclk);
+bus_clk_disable:
+ if (!IS_ERR(msm_host->bus_clk))
+ clk_disable_unprepare(msm_host->bus_clk);
+pltfm_free:
+ sdhci_pltfm_free(pdev);
+ return ret;
+}
+
+static int sdhci_msm_remove(struct platform_device *pdev)
+{
+ struct sdhci_host *host = platform_get_drvdata(pdev);
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_msm_host *msm_host = pltfm_host->priv;
+ int dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) ==
+ 0xffffffff);
+
+ sdhci_remove_host(host, dead);
+ sdhci_pltfm_free(pdev);
+ sdhci_msm_vreg_disable(&msm_host->pdata.vdd_data);
+ sdhci_msm_vreg_disable(&msm_host->pdata.vdd_io_data);
+ clk_disable_unprepare(msm_host->clk);
+ clk_disable_unprepare(msm_host->pclk);
+ if (!IS_ERR(msm_host->bus_clk))
+ clk_disable_unprepare(msm_host->bus_clk);
+ return 0;
+}
+
+static struct platform_driver sdhci_msm_driver = {
+ .probe = sdhci_msm_probe,
+ .remove = sdhci_msm_remove,
+ .driver = {
+ .name = "sdhci_msm",
+ .owner = THIS_MODULE,
+ .of_match_table = sdhci_msm_dt_match,
+ },
+};
+
+module_platform_driver(sdhci_msm_driver);
+
+MODULE_DESCRIPTION("Qualcomm Secure Digital Host Controller Interface driver");
+MODULE_LICENSE("GPL v2");
--
1.7.9.5


2013-09-17 14:56:40

by Stanimir Varbanov

[permalink] [raw]
Subject: Re: [PATCH v5] mmc: sdhci-msm: Add support for MSM chipsets

Hi Georgi,

Thanks for the patch.

I have some commnets below.

On 09/16/2013 05:23 PM, Georgi Djakov wrote:
> This platform driver adds the support of Secure Digital Host Controller
> Interface compliant controller found in Qualcomm MSM chipsets.
>
> CC: Asutosh Das <[email protected]>
> CC: Venkat Gopalakrishnan <[email protected]>
> CC: Sahitya Tummala <[email protected]>
> CC: Subhash Jadavani <[email protected]>
> Signed-off-by: Georgi Djakov <[email protected]>
> ---
> Changes from v4:
> - Simplified sdhci_msm_vreg_disable() and sdhci_msm_set_vdd_io_vol()
> - Use devm_ioremap_resource() instead of devm_ioremap()
> - Converted IS_ERR_OR_NULL to IS_ERR
> - Disable regulators in sdhci_msm_remove()
> - Check for DT node at the beginning in sdhci_msm_probe()
> - Removed more redundant code
> - Changes in some error messages
> - Minor fixes
>
> Changes from v3:
> - Allocate memory for all required structs at once
> - Added termination entry in sdhci_msm_dt_match[]
> - Fixed a missing sdhci_pltfm_free() in probe()
> - Removed redundant of_match_ptr
> - Removed the unneeded function sdhci_msm_vreg_reset()
>
> Changes from v2:
> - Added DT bindings for clocks
> - Moved voltage regulators data to platform data
> - Removed unneeded includes
> - Removed obsolete and wrapper functions
> - Removed error checking where unnecessary
> - Removed redundant _clk suffix from clock names
> - Just return instead of goto where possible
> - Minor fixes
>
> Changes from v1:
> - GPIO references are replaced by pinctrl
> - DT parsing is done mostly by mmc_of_parse()
> - Use of_match_device() for DT matching
> - A few minor changes
>
> .../devicetree/bindings/mmc/sdhci-msm.txt | 71 +++
> drivers/mmc/host/Kconfig | 13 +
> drivers/mmc/host/Makefile | 1 +
> drivers/mmc/host/sdhci-msm.c | 627 ++++++++++++++++++++
> 4 files changed, 712 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> create mode 100644 drivers/mmc/host/sdhci-msm.c
>
> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> new file mode 100644
> index 0000000..ee112da
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> @@ -0,0 +1,71 @@
> +* Qualcomm SDHCI controller (sdhci-msm)
> +
> +This file documents differences between the core properties in mmc.txt
> +and the properties used by the sdhci-msm driver.
> +
> +Required properties:
> +- compatible: should be "qcom,sdhci-msm"
> +- reg: should contain SDHC, SD Core register map
> +- reg-names: indicates various resources passed to driver (via reg proptery) by name
> + "reg-names" examples are "hc_mem" and "core_mem"
> +- interrupts: should contain SDHC interrupts
> +- interrupt-names: indicates interrupts passed to driver (via interrupts property) by name
> + "interrupt-names" examples are "hc_irq" and "pwr_irq"
> +- <supply-name>-supply: phandle to the regulator device tree node
> + "supply-name" examples are "vdd" and "vdd-io"
> +- pinctrl-names: Should contain only one value - "default".
> +- pinctrl-0: Should specify pin control groups used for this controller.
> +- clocks: phandles to clock instances of the device tree nodes
> +- clock-names:
> + iface: Main peripheral bus clock (PCLK/HCLK - AHB Bus clock) (required)
> + core: SDC MMC clock (MCLK) (required)
> + bus: SDCC bus voter clock (optional)
> +
> +Optional properties:
> +- qcom,bus-speed-mode - specifies supported bus speed modes by host
> + The supported bus speed modes are :
> + "HS200_1p8v" - indicates that host can support HS200 at 1.8v
> + "HS200_1p2v" - indicates that host can support HS200 at 1.2v
> + "DDR_1p8v" - indicates that host can support DDR mode at 1.8v
> + "DDR_1p2v" - indicates that host can support DDR mode at 1.2v
> +
> +In the following, <supply> can be vdd (flash core voltage) or vdd-io (I/O voltage).
> +- qcom,<supply>-always-on - specifies whether supply should be kept "on" always.
> +- qcom,<supply>-lpm-sup - specifies whether supply can be kept in low power mode (lpm).
> +- qcom,<supply>-voltage-level - specifies voltage levels for supply. Should be
> +specified in pairs (min, max), units uV.
> +- qcom,<supply>-current-level - specifies load levels for supply in lpm or high power mode
> + (hpm). Should be specified in pairs (lpm, hpm), units uA.
> +
> +Example:
> +
> + aliases {
> + sdhc1 = &sdhc_1;
> + };
> +
> + sdhc_1: qcom,sdhc@f9824900 {
> + compatible = "qcom,sdhci-msm";
> + reg = <0xf9824900 0x11c>, <0xf9824000 0x800>;
> + reg-names = "hc_mem", "core_mem";
> + interrupts = <0 123 0>, <0 138 0>;
> + interrupt-names = "hc_irq", "pwr_irq";
> + bus-width = <4>;
> + non-removable;
> +
> + vdd-supply = <&pm8941_l21>;
> + vdd-io-supply = <&pm8941_l13>;
> + qcom,vdd-voltage-level = <2950000 2950000>;
> + qcom,vdd-current-level = <9000 800000>;
> + qcom,vdd-io-always-on;
> + qcom,vdd-io-lpm-sup;
> + qcom,vdd-io-voltage-level = <1800000 2950000>;
> + qcom,vdd-io-current-level = <6 22000>;
> + qcom,bus-speed-mode = "HS200_1p8v", "DDR_1p8v";
> +
> + pinctrl-names = "default";
> + pinctrl-0 = <&sdc1_clk &sdc1_cmd &sdc1_data>;
> +
> + clocks = <&iface>, <&core>, <&bus>;
> + clock-names = "iface", "core", "bus";
> +
> + };
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 7fc5099..e8da488 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -322,6 +322,19 @@ config MMC_ATMELMCI
>
> If unsure, say N.
>
> +config MMC_SDHCI_MSM
> + tristate "Qualcomm SDHCI Controller Support"
> + depends on ARCH_MSM
> + depends on MMC_SDHCI_PLTFM
> + help
> + This selects the Secure Digital Host Controller Interface (SDHCI)
> + support present in MSM SOCs from Qualcomm. The controller
> + supports SD/MMC/SDIO devices.
> +
> + If you have a controller with this interface, say Y or M here.
> +
> + If unsure, say N.
> +
> config MMC_MSM
> tristate "Qualcomm SDCC Controller Support"
> depends on MMC && ARCH_MSM
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index c41d0c3..5faed14 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -61,6 +61,7 @@ obj-$(CONFIG_MMC_SDHCI_OF_ESDHC) += sdhci-of-esdhc.o
> obj-$(CONFIG_MMC_SDHCI_OF_HLWD) += sdhci-of-hlwd.o
> obj-$(CONFIG_MMC_SDHCI_BCM_KONA) += sdhci-bcm-kona.o
> obj-$(CONFIG_MMC_SDHCI_BCM2835) += sdhci-bcm2835.o
> +obj-$(CONFIG_MMC_SDHCI_MSM) += sdhci-msm.o
>
> ifeq ($(CONFIG_CB710_DEBUG),y)
> CFLAGS-cb710-mmc += -DDEBUG
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> new file mode 100644
> index 0000000..c746a9b
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -0,0 +1,627 @@
> +/*
> + * drivers/mmc/host/sdhci-msm.c - Qualcomm MSM SDHCI Platform
> + * driver source file
> + *
> + * Copyright (c) 2013, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/pinctrl/consumer.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include "sdhci-pltfm.h"
> +
> +#define CORE_HC_MODE 0x78
> +#define HC_MODE_EN 0x1
> +
> +#define CORE_POWER 0x0
> +#define CORE_SW_RST (1 << 7)
> +
> +#define CORE_PWRCTL_STATUS 0xdc
> +#define CORE_PWRCTL_MASK 0xe0
> +#define CORE_PWRCTL_CLEAR 0xe4
> +#define CORE_PWRCTL_CTL 0xe8
> +
> +#define CORE_PWRCTL_BUS_OFF 0x01
> +#define CORE_PWRCTL_BUS_ON (1 << 1)
> +#define CORE_PWRCTL_IO_LOW (1 << 2)
> +#define CORE_PWRCTL_IO_HIGH (1 << 3)
> +
> +#define CORE_PWRCTL_BUS_SUCCESS 0x01
> +#define CORE_PWRCTL_BUS_FAIL (1 << 1)
> +#define CORE_PWRCTL_IO_SUCCESS (1 << 2)
> +#define CORE_PWRCTL_IO_FAIL (1 << 3)
> +
> +#define INT_MASK 0xf
> +
> +/* This structure keeps information per regulator */
> +struct sdhci_msm_reg_data {
> + /* voltage regulator handle */

useless comment, please remove it.

> + struct regulator *reg;
> + /* regulator name */

useless comment

> + const char *name;
> + /* voltage level to be set */
> + u32 low_vol_level;
> + u32 high_vol_level;
> + /* Load values for low power and high power mode */
> + u32 lpm_uA;
> + u32 hpm_uA;
> +
> + /* is this regulator needs to be always on? */
> + bool is_always_on;
> + /* is low power mode setting required for this regulator? */
> + bool lpm_sup;
> +};
> +
> +struct sdhci_msm_pltfm_data {
> + u32 caps; /* Supported UHS-I Modes */
> + u32 caps2; /* More capabilities */
> + struct sdhci_msm_reg_data vdd_data; /* VDD/VCC regulator info */
> + struct sdhci_msm_reg_data vdd_io_data; /* VDD IO regulator info */
> +};
> +
> +struct sdhci_msm_host {
> + struct platform_device *pdev;
> + void __iomem *core_mem; /* MSM SDCC mapped address */
> + int pwr_irq; /* power irq */
> + struct clk *clk; /* main SD/MMC bus clock */
> + struct clk *pclk; /* SDHC peripheral bus clock */
> + struct clk *bus_clk; /* SDHC bus voter clock */
> + struct sdhci_msm_pltfm_data pdata;
> + struct mmc_host *mmc;
> + struct sdhci_pltfm_data sdhci_msm_pdata;
> +};
> +
> +enum vdd_io_level {
> + /* set vdd_io_data->low_vol_level */
> + VDD_IO_LOW,
> + /* set vdd_io_data->high_vol_level */
> + VDD_IO_HIGH,
> + /*
> + * set whatever there in voltage_level (third argument) of
> + * sdhci_msm_set_vdd_io_vol() function.
> + */
> + VDD_IO_SET_LEVEL,
> +};
> +
> +#define MAX_PROP_SIZE 32
> +static int sdhci_msm_dt_parse_vreg_info(struct device *dev,
> + struct sdhci_msm_reg_data *vreg,
> + const char *vreg_name)
> +{
> + int len, ret = 0;

ret is not used you can remove it and return 0 at the function end.

> + const __be32 *prop;
> + char prop_name[MAX_PROP_SIZE];
> + struct device_node *np = dev->of_node;
> +
> + snprintf(prop_name, MAX_PROP_SIZE, "%s-supply", vreg_name);
> + if (!of_parse_phandle(np, prop_name, 0)) {
> + dev_info(dev, "No vreg data found for %s\n", vreg_name);
> + return -EINVAL;
> + }
> +
> + vreg->name = vreg_name;
> +
> + snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-always-on", vreg_name);
> + if (of_get_property(np, prop_name, NULL))
> + vreg->is_always_on = true;
> +
> + snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-lpm-sup", vreg_name);
> + if (of_get_property(np, prop_name, NULL))
> + vreg->lpm_sup = true;
> +
> + snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-voltage-level", vreg_name);
> + prop = of_get_property(np, prop_name, &len);
> + if (!prop || (len != (2 * sizeof(__be32)))) {
> + dev_warn(dev, "%s %s property\n",
> + prop ? "invalid format" : "no", prop_name);
> + } else {
> + vreg->low_vol_level = be32_to_cpup(&prop[0]);
> + vreg->high_vol_level = be32_to_cpup(&prop[1]);
> + }
> +
> + snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-current-level", vreg_name);
> + prop = of_get_property(np, prop_name, &len);
> + if (!prop || (len != (2 * sizeof(__be32)))) {
> + dev_warn(dev, "%s %s property\n",
> + prop ? "invalid format" : "no", prop_name);
> + } else {
> + vreg->lpm_uA = be32_to_cpup(&prop[0]);
> + vreg->hpm_uA = be32_to_cpup(&prop[1]);
> + }
> +
> + dev_dbg(dev, "%s: %s%svol=[%d %d]uV, curr=[%d %d]uA\n",
> + vreg->name, vreg->is_always_on ? "always_on, " : "",
> + vreg->lpm_sup ? "lpm_sup, " : "", vreg->low_vol_level,
> + vreg->high_vol_level, vreg->lpm_uA, vreg->hpm_uA);
> +
> + return ret;
> +}
> +
> +/* Parse platform data */

parse devicetree data ?

> +static int sdhci_msm_populate_pdata(struct device *dev,
> + struct sdhci_msm_pltfm_data *pdata)
> +{
> + struct device_node *np = dev->of_node;
> + int len, i;
> +
> + if (sdhci_msm_dt_parse_vreg_info(dev, &pdata->vdd_data, "vdd")) {
> + dev_err(dev, "failed parsing vdd data\n");
> + return -EINVAL;
> + }
> + if (sdhci_msm_dt_parse_vreg_info(dev, &pdata->vdd_io_data, "vdd-io")) {
> + dev_err(dev, "failed parsing vdd-io data\n");
> + return -EINVAL;
> + }
> +
> + len = of_property_count_strings(np, "qcom,bus-speed-mode");
> +
> + for (i = 0; i < len; i++) {
> + const char *name = NULL;
> +
> + of_property_read_string_index(np,
> + "qcom,bus-speed-mode", i, &name);
> + if (!name)
> + continue;
> +
> + if (!strncmp(name, "HS200_1p8v", sizeof("HS200_1p8v")))
> + pdata->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
> + else if (!strncmp(name, "HS200_1p2v", sizeof("HS200_1p2v")))
> + pdata->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
> + else if (!strncmp(name, "DDR_1p8v", sizeof("DDR_1p8v")))
> + pdata->caps |= MMC_CAP_1_8V_DDR | MMC_CAP_UHS_DDR50;
> + else if (!strncmp(name, "DDR_1p2v", sizeof("DDR_1p2v")))
> + pdata->caps |= MMC_CAP_1_2V_DDR | MMC_CAP_UHS_DDR50;
> + }
> +
> + return 0;
> +}
> +
> +/* Regulator utility functions */
> +static int sdhci_msm_vreg_init_reg(struct device *dev,
> + struct sdhci_msm_reg_data *vreg)
> +{
> + int ret = 0;

could you remove ret variable, please.

> + /* Get the regulator handle */

useless comment

> + vreg->reg = devm_regulator_get(dev, vreg->name);
> + if (IS_ERR(vreg->reg)) {
> + ret = PTR_ERR(vreg->reg);
> + dev_err(dev, "devm_regulator_get(%s) failed. ret=%d\n",
> + vreg->name, ret);
> + return ret;

just return PTR_ERR(vreg->reg)

> + }
> +
> + /* sanity check */
> + if (!vreg->high_vol_level || !vreg->hpm_uA) {

if this is sanity check shouldn't you check low_vol_level and lpm_uA as
well?

> + dev_err(dev, "%s invalid constraints specified\n", vreg->name);
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int sdhci_msm_vreg_enable(struct sdhci_msm_reg_data *vreg)
> +{
> + int ret = 0;
> +
> + /* Put regulator in HPM (high power mode) */
> + ret = regulator_set_optimum_mode(vreg->reg, vreg->hpm_uA);
> + if (ret < 0) {
> + pr_err("regulator_set_optimum_mode(%s,uA_load=%d) fail (%d)\n",
> + vreg->name, vreg->hpm_uA, ret);

use dev_err() instead.

> + return ret;
> + }
> +
> + if (!regulator_is_enabled(vreg->reg)) {
> + /* Set voltage level */
> + ret = regulator_set_voltage(vreg->reg, vreg->high_vol_level,
> + vreg->high_vol_level);
> + if (ret)
> + return ret;
> + }
> +
> + ret = regulator_enable(vreg->reg);
> + if (ret) {
> + pr_err("regulator_enable(%s) fail (%d)\n", vreg->name, ret);

use dev_err().

> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int sdhci_msm_vreg_disable(struct sdhci_msm_reg_data *vreg)
> +{
> + int ret = 0;

IMO no need to initialize ret variable?

> +
> + if (!regulator_is_enabled(vreg->reg))
> + return 0;
> +
> + /* Never disable regulator marked as always_on */
> + if (vreg->is_always_on) {
> + if (vreg->lpm_sup) {
> + /* Put always_on regulator in LPM (low power mode) */
> + ret = regulator_set_optimum_mode(vreg->reg,
> + vreg->lpm_uA);
> + if (ret < 0)
> + return ret;
> + }
> + } else {
> + ret = regulator_disable(vreg->reg);
> + if (ret) {
> + pr_err("regulator_disable(%s) fail (%d)\n",
> + vreg->name, ret);

dev_err(), please.

> + return ret;
> + }
> +
> + ret = regulator_set_optimum_mode(vreg->reg, 0);
> + if (ret < 0)
> + return ret;
> +
> + /* Set min. voltage level to 0 */
> + ret = regulator_set_voltage(vreg->reg, 0, vreg->high_vol_level);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int sdhci_msm_setup_vreg(struct sdhci_msm_pltfm_data *pdata,
> + bool enable, bool is_init)
> +{
> + int ret = 0, i;

no need to initialize ret variable?

> + struct sdhci_msm_reg_data *vreg_table[2];
> +
> + vreg_table[0] = &pdata->vdd_data;
> + vreg_table[1] = &pdata->vdd_io_data;
> +
> + for (i = 0; i < ARRAY_SIZE(vreg_table); i++) {
> + if (vreg_table[i]) {

could you invert the logic here:

if (!vreg_table[i])
continue;

by that way you will save one tab below.

> + if (enable)
> + ret = sdhci_msm_vreg_enable(vreg_table[i]);
> + else
> + ret = sdhci_msm_vreg_disable(vreg_table[i]);
> + if (ret)
> + return ret;
> + }
> + }

blank line ?

> + return 0;
> +}
> +
> +/* This init function should be called only once for each SDHC slot */
> +static int sdhci_msm_vreg_init(struct device *dev,
> + struct sdhci_msm_pltfm_data *pdata)
> +{
> + struct sdhci_msm_reg_data *curr_vdd_reg = &pdata->vdd_data;
> + struct sdhci_msm_reg_data *curr_vdd_io_reg = &pdata->vdd_io_data;
> + int ret = 0;

no need to initialize ret variable.

> +
> + ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_reg);
> + if (ret)
> + return ret;
> +
> + ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_io_reg);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +static int sdhci_msm_set_vdd_io_vol(struct sdhci_msm_pltfm_data *pdata,
> + enum vdd_io_level level,
> + unsigned int voltage_level)
> +{
> + int set_level;
> + struct sdhci_msm_reg_data *vdd_io_reg = &pdata->vdd_io_data;
> +
> + if (!regulator_is_enabled(vdd_io_reg->reg))
> + return 0;
> +
> + switch (level) {
> + case VDD_IO_LOW:
> + set_level = vdd_io_reg->low_vol_level;
> + break;
> + case VDD_IO_HIGH:
> + set_level = vdd_io_reg->high_vol_level;
> + break;
> + case VDD_IO_SET_LEVEL:
> + set_level = voltage_level;
> + break;
> + default:
> + pr_err("invalid vdd_io level = %d", level);
> + return -EINVAL;
> + }

add blank line here, please.

> + return regulator_set_voltage(vdd_io_reg->reg, set_level, set_level);
> +}
> +
> +static irqreturn_t sdhci_msm_pwr_irq(int irq, void *data)
> +{
> + struct sdhci_msm_host *msm_host = (struct sdhci_msm_host *)data;
> + u8 irq_status = 0;
> + u8 irq_ack = 0;
> + int ret = 0;

no need to initialize irq_status and ret, right?

> +
> + irq_status = readb_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);
> + pr_debug("%s: Received IRQ(%d), status=0x%x\n",
> + mmc_hostname(msm_host->mmc), irq, irq_status);

dev_dbg() ?

> +
> + /* Clear the interrupt */
> + writeb_relaxed(irq_status, (msm_host->core_mem + CORE_PWRCTL_CLEAR));

why you use writeb here, but in .probe you use writel?

> + /*
> + * SDHC has core_mem and hc_mem device memory and these memory
> + * addresses do not fall within 1KB region. Hence, any update to
> + * core_mem address space would require an mb() to ensure this gets
> + * completed before its next update to registers within hc_mem.
> + */
> + mb();
> +
> + /* Handle BUS ON/OFF */
> + if (irq_status & (CORE_PWRCTL_BUS_ON | CORE_PWRCTL_BUS_OFF)) {
> + bool flag = (irq_status & CORE_PWRCTL_BUS_ON) ? 1 : 0;
> + ret = sdhci_msm_setup_vreg(&msm_host->pdata, flag, false);
> + if (ret)
> + irq_ack |= CORE_PWRCTL_BUS_FAIL;
> + else
> + irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
> + }
> + /* Handle IO LOW/HIGH */
> + if (irq_status & (CORE_PWRCTL_IO_LOW | CORE_PWRCTL_IO_HIGH)) {
> + /* Switch voltage */
> + int io_status = (irq_status & CORE_PWRCTL_IO_LOW) ?
> + VDD_IO_LOW : VDD_IO_HIGH;
> + ret = sdhci_msm_set_vdd_io_vol(&msm_host->pdata, io_status, 0);
> + if (ret)
> + irq_ack |= CORE_PWRCTL_IO_FAIL;
> + else
> + irq_ack |= CORE_PWRCTL_IO_SUCCESS;
> + }
> +
> + /* ACK status to the core */
> + writeb_relaxed(irq_ack, (msm_host->core_mem + CORE_PWRCTL_CTL));
> + /*
> + * SDHC has core_mem and hc_mem device memory and these memory
> + * addresses do not fall within 1KB region. Hence, any update to
> + * core_mem address space would require an mb() to ensure this gets
> + * completed before its next update to registers within hc_mem.
> + */
> + mb();
> +
> + pr_debug("%s: Handled IRQ(%d), ret=%d, ack=0x%x\n",
> + mmc_hostname(msm_host->mmc), irq, ret, irq_ack);

dev_dbg() ?

> + return IRQ_HANDLED;
> +}
> +
> +/* This function returns the max. current supported by VDD rail in mA */
> +static u32 sdhci_msm_get_vdd_max_current(struct sdhci_msm_host *host)
> +{
> + return host->pdata.vdd_data.hpm_uA / 1000;
> +}
> +
> +static const struct of_device_id sdhci_msm_dt_match[] = {
> + {.compatible = "qcom,sdhci-msm"},
> + {},
> +};
> +
> +MODULE_DEVICE_TABLE(of, sdhci_msm_dt_match);
> +
> +static int sdhci_msm_probe(struct platform_device *pdev)
> +{
> + struct sdhci_host *host;
> + struct sdhci_pltfm_host *pltfm_host;
> + struct sdhci_msm_host *msm_host;
> + struct resource *core_memres = NULL;
> + int ret = 0, dead = 0;

no need to initialize ret and dead variables.

> + struct pinctrl *pinctrl;
> +
> + if (!pdev->dev.of_node) {
> + dev_err(&pdev->dev, "No device tree data\n");
> + return -ENOENT;
> + }
> +
> + msm_host = devm_kzalloc(&pdev->dev, sizeof(*msm_host), GFP_KERNEL);
> + if (!msm_host)
> + return -ENOMEM;
> +
> + host = sdhci_pltfm_init(pdev, &msm_host->sdhci_msm_pdata, 0);
> + if (IS_ERR(host)) {
> + dev_err(mmc_dev(host->mmc), "sdhci_pltfm_init error\n");
> + return PTR_ERR(host);
> + }
> +
> + pltfm_host = sdhci_priv(host);
> + pltfm_host->priv = msm_host;
> + msm_host->mmc = host->mmc;
> + msm_host->pdev = pdev;
> +
> + ret = mmc_of_parse(host->mmc);
> + if (ret) {
> + dev_err(&pdev->dev, "failed parsing mmc device tree\n");
> + goto pltfm_free;
> + }
> +
> + /* Extract platform data */

needless comment, again.

> + ret = sdhci_msm_populate_pdata(&pdev->dev, &msm_host->pdata);
> + if (ret) {
> + dev_err(&pdev->dev, "DT parsing error\n");
> + goto pltfm_free;
> + }
> +
> + /* Setup pins */
> + pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
> + if (IS_ERR(pinctrl))
> + dev_warn(&pdev->dev, "pins are not configured by the driver\n");
> +
> + /* Setup SDCC bus voter clock. */
> + msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus");
> + if (!IS_ERR(msm_host->bus_clk)) {
> + /* Vote for max. clk rate for max. performance */
> + ret = clk_set_rate(msm_host->bus_clk, INT_MAX);
> + if (ret)
> + goto pltfm_free;
> + ret = clk_prepare_enable(msm_host->bus_clk);
> + if (ret)
> + goto pltfm_free;
> + }
> +
> + /* Setup main peripheral bus clock */
> + msm_host->pclk = devm_clk_get(&pdev->dev, "iface");
> + if (!IS_ERR(msm_host->pclk)) {
> + ret = clk_prepare_enable(msm_host->pclk);
> + if (ret) {
> + dev_err(&pdev->dev,
> + "Main peripheral clock setup failed (%d)\n",
> + ret);
> + goto bus_clk_disable;
> + }
> + }
> +
> + /* Setup SDC MMC clock */
> + msm_host->clk = devm_clk_get(&pdev->dev, "core");
> + if (IS_ERR(msm_host->clk)) {
> + ret = PTR_ERR(msm_host->clk);
> + dev_err(&pdev->dev, "SDC MMC clock setup failed (%d)\n", ret);
> + goto pclk_disable;
> + }
> +
> + ret = clk_prepare_enable(msm_host->clk);
> + if (ret)
> + goto pclk_disable;
> +
> + /* Setup regulators */
> + ret = sdhci_msm_vreg_init(&pdev->dev, &msm_host->pdata);
> + if (ret) {
> + dev_err(&pdev->dev, "Regulator setup failed (%d)\n", ret);
> + goto clk_disable;
> + }
> +
> + /* Reset the core and Enable SDHC mode */

this comment should go few lines below.

> + core_memres = platform_get_resource_byname(pdev,
> + IORESOURCE_MEM, "core_mem");
> + msm_host->core_mem = devm_ioremap_resource(&pdev->dev, core_memres);
> +
> + if (IS_ERR(msm_host->core_mem)) {
> + dev_err(&pdev->dev, "Failed to remap registers\n");
> + ret = PTR_ERR(msm_host->core_mem);
> + goto vreg_disable;
> + }
> +
> + /* Set SW_RST bit in POWER register (Offset 0x0) */

those comments are stupid, please remove them.

> + writel_relaxed(CORE_SW_RST, msm_host->core_mem + CORE_POWER);
> + /* Set HC_MODE_EN bit in HC_MODE register */
> + writel_relaxed(HC_MODE_EN, (msm_host->core_mem + CORE_HC_MODE));
> +

are all interrupts disabled at this point?

> + /*
> + * Following are the deviations from SDHC spec v3.0 -
> + * 1. Card detection is handled using separate GPIO.
> + * 2. Bus power control is handled by interacting with PMIC.
> + */
> + host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
> +
> + /* Setup PWRCTL irq */
> + msm_host->pwr_irq = platform_get_irq_byname(pdev, "pwr_irq");
> + if (msm_host->pwr_irq < 0) {
> + dev_err(&pdev->dev, "Failed to get pwr_irq by name (%d)\n",
> + msm_host->pwr_irq);
> + goto vreg_disable;
> + }
> + ret = devm_request_threaded_irq(&pdev->dev, msm_host->pwr_irq, NULL,
> + sdhci_msm_pwr_irq, IRQF_ONESHOT,
> + dev_name(&pdev->dev), host);
> + if (ret) {
> + dev_err(&pdev->dev, "Request threaded irq(%d) failed (%d)\n",
> + msm_host->pwr_irq, ret);
> + goto vreg_disable;
> + }
> +
> + /* Enable pwr irq interrupts */
> + writel_relaxed(INT_MASK, (msm_host->core_mem + CORE_PWRCTL_MASK));
> +
> + /* Set host capabilities */

useless comment

> + msm_host->mmc->caps |= msm_host->pdata.caps;
> + msm_host->mmc->caps2 |= msm_host->pdata.caps2;
> +
> + ret = sdhci_add_host(host);
> + if (ret) {
> + dev_err(&pdev->dev, "Add host failed (%d)\n", ret);
> + goto vreg_disable;
> + }
> +
> + /* Set core clk rate */

useless comment

> + ret = clk_set_rate(msm_host->clk, host->max_clk);
> + if (ret) {
> + dev_err(&pdev->dev, "MClk rate set failed (%d)\n", ret);
> + goto remove_host;
> + }
> +
> + host->mmc->max_current_180 = host->mmc->max_current_300 =
> + host->mmc->max_current_330 = sdhci_msm_get_vdd_max_current(msm_host);
> +
> + /* Successful initialization */

useless comment

> + return 0;
> +
> +remove_host:
> + dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
> + sdhci_remove_host(host, dead);
> +vreg_disable:
> + if (!IS_ERR(msm_host->pdata.vdd_data.reg))
> + sdhci_msm_vreg_disable(&msm_host->pdata.vdd_data);
> + if (!IS_ERR(msm_host->pdata.vdd_io_data.reg))
> + sdhci_msm_vreg_disable(&msm_host->pdata.vdd_io_data);
> +clk_disable:
> + if (!IS_ERR(msm_host->clk))
> + clk_disable_unprepare(msm_host->clk);
> +pclk_disable:
> + if (!IS_ERR(msm_host->pclk))
> + clk_disable_unprepare(msm_host->pclk);
> +bus_clk_disable:
> + if (!IS_ERR(msm_host->bus_clk))
> + clk_disable_unprepare(msm_host->bus_clk);
> +pltfm_free:
> + sdhci_pltfm_free(pdev);
> + return ret;
> +}
> +
> +static int sdhci_msm_remove(struct platform_device *pdev)
> +{
> + struct sdhci_host *host = platform_get_drvdata(pdev);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_msm_host *msm_host = pltfm_host->priv;
> + int dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) ==
> + 0xffffffff);
> +
> + sdhci_remove_host(host, dead);
> + sdhci_pltfm_free(pdev);
> + sdhci_msm_vreg_disable(&msm_host->pdata.vdd_data);
> + sdhci_msm_vreg_disable(&msm_host->pdata.vdd_io_data);
> + clk_disable_unprepare(msm_host->clk);
> + clk_disable_unprepare(msm_host->pclk);
> + if (!IS_ERR(msm_host->bus_clk))
> + clk_disable_unprepare(msm_host->bus_clk);
> + return 0;
> +}
> +
> +static struct platform_driver sdhci_msm_driver = {
> + .probe = sdhci_msm_probe,
> + .remove = sdhci_msm_remove,
> + .driver = {
> + .name = "sdhci_msm",
> + .owner = THIS_MODULE,
> + .of_match_table = sdhci_msm_dt_match,
> + },

this bracket should be under ".driver".

> +};
> +
> +module_platform_driver(sdhci_msm_driver);
> +
> +MODULE_DESCRIPTION("Qualcomm Secure Digital Host Controller Interface driver");
> +MODULE_LICENSE("GPL v2");
>

2013-09-18 15:40:50

by Georgi Djakov

[permalink] [raw]
Subject: Re: [PATCH v5] mmc: sdhci-msm: Add support for MSM chipsets

Hi Stan,

Thank you for the detailed review on this patch.

On 09/17/2013 05:55 PM, Stanimir Varbanov wrote:
> Hi Georgi,
>
> Thanks for the patch.
>
> I have some commnets below.
>
> On 09/16/2013 05:23 PM, Georgi Djakov wrote:
>> This platform driver adds the support of Secure Digital Host Controller
>> Interface compliant controller found in Qualcomm MSM chipsets.
>>
>> CC: Asutosh Das <[email protected]>
>> CC: Venkat Gopalakrishnan <[email protected]>
>> CC: Sahitya Tummala <[email protected]>
>> CC: Subhash Jadavani <[email protected]>
>> Signed-off-by: Georgi Djakov <[email protected]>
>> ---
>> Changes from v4:
>> - Simplified sdhci_msm_vreg_disable() and sdhci_msm_set_vdd_io_vol()
>> - Use devm_ioremap_resource() instead of devm_ioremap()
>> - Converted IS_ERR_OR_NULL to IS_ERR
>> - Disable regulators in sdhci_msm_remove()
>> - Check for DT node at the beginning in sdhci_msm_probe()
>> - Removed more redundant code
>> - Changes in some error messages
>> - Minor fixes
>>
>> Changes from v3:
>> - Allocate memory for all required structs at once
>> - Added termination entry in sdhci_msm_dt_match[]
>> - Fixed a missing sdhci_pltfm_free() in probe()
>> - Removed redundant of_match_ptr
>> - Removed the unneeded function sdhci_msm_vreg_reset()
>>
>> Changes from v2:
>> - Added DT bindings for clocks
>> - Moved voltage regulators data to platform data
>> - Removed unneeded includes
>> - Removed obsolete and wrapper functions
>> - Removed error checking where unnecessary
>> - Removed redundant _clk suffix from clock names
>> - Just return instead of goto where possible
>> - Minor fixes
>>
>> Changes from v1:
>> - GPIO references are replaced by pinctrl
>> - DT parsing is done mostly by mmc_of_parse()
>> - Use of_match_device() for DT matching
>> - A few minor changes
>>
>> .../devicetree/bindings/mmc/sdhci-msm.txt | 71 +++
>> drivers/mmc/host/Kconfig | 13 +
>> drivers/mmc/host/Makefile | 1 +
>> drivers/mmc/host/sdhci-msm.c | 627 ++++++++++++++++++++
>> 4 files changed, 712 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> create mode 100644 drivers/mmc/host/sdhci-msm.c
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> new file mode 100644
>> index 0000000..ee112da
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
>> @@ -0,0 +1,71 @@
>> +* Qualcomm SDHCI controller (sdhci-msm)
>> +
>> +This file documents differences between the core properties in mmc.txt
>> +and the properties used by the sdhci-msm driver.
>> +
>> +Required properties:
>> +- compatible: should be "qcom,sdhci-msm"
>> +- reg: should contain SDHC, SD Core register map
>> +- reg-names: indicates various resources passed to driver (via reg proptery) by name
>> + "reg-names" examples are "hc_mem" and "core_mem"
>> +- interrupts: should contain SDHC interrupts
>> +- interrupt-names: indicates interrupts passed to driver (via interrupts property) by name
>> + "interrupt-names" examples are "hc_irq" and "pwr_irq"
>> +- <supply-name>-supply: phandle to the regulator device tree node
>> + "supply-name" examples are "vdd" and "vdd-io"
>> +- pinctrl-names: Should contain only one value - "default".
>> +- pinctrl-0: Should specify pin control groups used for this controller.
>> +- clocks: phandles to clock instances of the device tree nodes
>> +- clock-names:
>> + iface: Main peripheral bus clock (PCLK/HCLK - AHB Bus clock) (required)
>> + core: SDC MMC clock (MCLK) (required)
>> + bus: SDCC bus voter clock (optional)
>> +
>> +Optional properties:
>> +- qcom,bus-speed-mode - specifies supported bus speed modes by host
>> + The supported bus speed modes are :
>> + "HS200_1p8v" - indicates that host can support HS200 at 1.8v
>> + "HS200_1p2v" - indicates that host can support HS200 at 1.2v
>> + "DDR_1p8v" - indicates that host can support DDR mode at 1.8v
>> + "DDR_1p2v" - indicates that host can support DDR mode at 1.2v
>> +
>> +In the following, <supply> can be vdd (flash core voltage) or vdd-io (I/O voltage).
>> +- qcom,<supply>-always-on - specifies whether supply should be kept "on" always.
>> +- qcom,<supply>-lpm-sup - specifies whether supply can be kept in low power mode (lpm).
>> +- qcom,<supply>-voltage-level - specifies voltage levels for supply. Should be
>> +specified in pairs (min, max), units uV.
>> +- qcom,<supply>-current-level - specifies load levels for supply in lpm or high power mode
>> + (hpm). Should be specified in pairs (lpm, hpm), units uA.
>> +
>> +Example:
>> +
>> + aliases {
>> + sdhc1 = &sdhc_1;
>> + };
>> +
>> + sdhc_1: qcom,sdhc@f9824900 {
>> + compatible = "qcom,sdhci-msm";
>> + reg = <0xf9824900 0x11c>, <0xf9824000 0x800>;
>> + reg-names = "hc_mem", "core_mem";
>> + interrupts = <0 123 0>, <0 138 0>;
>> + interrupt-names = "hc_irq", "pwr_irq";
>> + bus-width = <4>;
>> + non-removable;
>> +
>> + vdd-supply = <&pm8941_l21>;
>> + vdd-io-supply = <&pm8941_l13>;
>> + qcom,vdd-voltage-level = <2950000 2950000>;
>> + qcom,vdd-current-level = <9000 800000>;
>> + qcom,vdd-io-always-on;
>> + qcom,vdd-io-lpm-sup;
>> + qcom,vdd-io-voltage-level = <1800000 2950000>;
>> + qcom,vdd-io-current-level = <6 22000>;
>> + qcom,bus-speed-mode = "HS200_1p8v", "DDR_1p8v";
>> +
>> + pinctrl-names = "default";
>> + pinctrl-0 = <&sdc1_clk &sdc1_cmd &sdc1_data>;
>> +
>> + clocks = <&iface>, <&core>, <&bus>;
>> + clock-names = "iface", "core", "bus";
>> +
>> + };
>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>> index 7fc5099..e8da488 100644
>> --- a/drivers/mmc/host/Kconfig
>> +++ b/drivers/mmc/host/Kconfig
>> @@ -322,6 +322,19 @@ config MMC_ATMELMCI
>>
>> If unsure, say N.
>>
>> +config MMC_SDHCI_MSM
>> + tristate "Qualcomm SDHCI Controller Support"
>> + depends on ARCH_MSM
>> + depends on MMC_SDHCI_PLTFM
>> + help
>> + This selects the Secure Digital Host Controller Interface (SDHCI)
>> + support present in MSM SOCs from Qualcomm. The controller
>> + supports SD/MMC/SDIO devices.
>> +
>> + If you have a controller with this interface, say Y or M here.
>> +
>> + If unsure, say N.
>> +
>> config MMC_MSM
>> tristate "Qualcomm SDCC Controller Support"
>> depends on MMC && ARCH_MSM
>> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
>> index c41d0c3..5faed14 100644
>> --- a/drivers/mmc/host/Makefile
>> +++ b/drivers/mmc/host/Makefile
>> @@ -61,6 +61,7 @@ obj-$(CONFIG_MMC_SDHCI_OF_ESDHC) += sdhci-of-esdhc.o
>> obj-$(CONFIG_MMC_SDHCI_OF_HLWD) += sdhci-of-hlwd.o
>> obj-$(CONFIG_MMC_SDHCI_BCM_KONA) += sdhci-bcm-kona.o
>> obj-$(CONFIG_MMC_SDHCI_BCM2835) += sdhci-bcm2835.o
>> +obj-$(CONFIG_MMC_SDHCI_MSM) += sdhci-msm.o
>>
>> ifeq ($(CONFIG_CB710_DEBUG),y)
>> CFLAGS-cb710-mmc += -DDEBUG
>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>> new file mode 100644
>> index 0000000..c746a9b
>> --- /dev/null
>> +++ b/drivers/mmc/host/sdhci-msm.c
>> @@ -0,0 +1,627 @@
>> +/*
>> + * drivers/mmc/host/sdhci-msm.c - Qualcomm MSM SDHCI Platform
>> + * driver source file
>> + *
>> + * Copyright (c) 2013, The Linux Foundation. All rights reserved.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 and
>> + * only version 2 as published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + *
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>> +#include <linux/pinctrl/consumer.h>
>> +#include <linux/regulator/consumer.h>
>> +
>> +#include "sdhci-pltfm.h"
>> +
>> +#define CORE_HC_MODE 0x78
>> +#define HC_MODE_EN 0x1
>> +
>> +#define CORE_POWER 0x0
>> +#define CORE_SW_RST (1 << 7)
>> +
>> +#define CORE_PWRCTL_STATUS 0xdc
>> +#define CORE_PWRCTL_MASK 0xe0
>> +#define CORE_PWRCTL_CLEAR 0xe4
>> +#define CORE_PWRCTL_CTL 0xe8
>> +
>> +#define CORE_PWRCTL_BUS_OFF 0x01
>> +#define CORE_PWRCTL_BUS_ON (1 << 1)
>> +#define CORE_PWRCTL_IO_LOW (1 << 2)
>> +#define CORE_PWRCTL_IO_HIGH (1 << 3)
>> +
>> +#define CORE_PWRCTL_BUS_SUCCESS 0x01
>> +#define CORE_PWRCTL_BUS_FAIL (1 << 1)
>> +#define CORE_PWRCTL_IO_SUCCESS (1 << 2)
>> +#define CORE_PWRCTL_IO_FAIL (1 << 3)
>> +
>> +#define INT_MASK 0xf
>> +
>> +/* This structure keeps information per regulator */
>> +struct sdhci_msm_reg_data {
>> + /* voltage regulator handle */
>
> useless comment, please remove it.

Ok.

>
>> + struct regulator *reg;
>> + /* regulator name */
>
> useless comment

Ok.

>
>> + const char *name;
>> + /* voltage level to be set */
>> + u32 low_vol_level;
>> + u32 high_vol_level;
>> + /* Load values for low power and high power mode */
>> + u32 lpm_uA;
>> + u32 hpm_uA;
>> +
>> + /* is this regulator needs to be always on? */
>> + bool is_always_on;
>> + /* is low power mode setting required for this regulator? */
>> + bool lpm_sup;
>> +};
>> +
>> +struct sdhci_msm_pltfm_data {
>> + u32 caps; /* Supported UHS-I Modes */
>> + u32 caps2; /* More capabilities */
>> + struct sdhci_msm_reg_data vdd_data; /* VDD/VCC regulator info */
>> + struct sdhci_msm_reg_data vdd_io_data; /* VDD IO regulator info */
>> +};
>> +
>> +struct sdhci_msm_host {
>> + struct platform_device *pdev;
>> + void __iomem *core_mem; /* MSM SDCC mapped address */
>> + int pwr_irq; /* power irq */
>> + struct clk *clk; /* main SD/MMC bus clock */
>> + struct clk *pclk; /* SDHC peripheral bus clock */
>> + struct clk *bus_clk; /* SDHC bus voter clock */
>> + struct sdhci_msm_pltfm_data pdata;
>> + struct mmc_host *mmc;
>> + struct sdhci_pltfm_data sdhci_msm_pdata;
>> +};
>> +
>> +enum vdd_io_level {
>> + /* set vdd_io_data->low_vol_level */
>> + VDD_IO_LOW,
>> + /* set vdd_io_data->high_vol_level */
>> + VDD_IO_HIGH,
>> + /*
>> + * set whatever there in voltage_level (third argument) of
>> + * sdhci_msm_set_vdd_io_vol() function.
>> + */
>> + VDD_IO_SET_LEVEL,
>> +};
>> +
>> +#define MAX_PROP_SIZE 32
>> +static int sdhci_msm_dt_parse_vreg_info(struct device *dev,
>> + struct sdhci_msm_reg_data *vreg,
>> + const char *vreg_name)
>> +{
>> + int len, ret = 0;
>
> ret is not used you can remove it and return 0 at the function end.

Ok.

>
>> + const __be32 *prop;
>> + char prop_name[MAX_PROP_SIZE];
>> + struct device_node *np = dev->of_node;
>> +
>> + snprintf(prop_name, MAX_PROP_SIZE, "%s-supply", vreg_name);
>> + if (!of_parse_phandle(np, prop_name, 0)) {
>> + dev_info(dev, "No vreg data found for %s\n", vreg_name);
>> + return -EINVAL;
>> + }
>> +
>> + vreg->name = vreg_name;
>> +
>> + snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-always-on", vreg_name);
>> + if (of_get_property(np, prop_name, NULL))
>> + vreg->is_always_on = true;
>> +
>> + snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-lpm-sup", vreg_name);
>> + if (of_get_property(np, prop_name, NULL))
>> + vreg->lpm_sup = true;
>> +
>> + snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-voltage-level", vreg_name);
>> + prop = of_get_property(np, prop_name, &len);
>> + if (!prop || (len != (2 * sizeof(__be32)))) {
>> + dev_warn(dev, "%s %s property\n",
>> + prop ? "invalid format" : "no", prop_name);
>> + } else {
>> + vreg->low_vol_level = be32_to_cpup(&prop[0]);
>> + vreg->high_vol_level = be32_to_cpup(&prop[1]);
>> + }
>> +
>> + snprintf(prop_name, MAX_PROP_SIZE, "qcom,%s-current-level", vreg_name);
>> + prop = of_get_property(np, prop_name, &len);
>> + if (!prop || (len != (2 * sizeof(__be32)))) {
>> + dev_warn(dev, "%s %s property\n",
>> + prop ? "invalid format" : "no", prop_name);
>> + } else {
>> + vreg->lpm_uA = be32_to_cpup(&prop[0]);
>> + vreg->hpm_uA = be32_to_cpup(&prop[1]);
>> + }
>> +
>> + dev_dbg(dev, "%s: %s%svol=[%d %d]uV, curr=[%d %d]uA\n",
>> + vreg->name, vreg->is_always_on ? "always_on, " : "",
>> + vreg->lpm_sup ? "lpm_sup, " : "", vreg->low_vol_level,
>> + vreg->high_vol_level, vreg->lpm_uA, vreg->hpm_uA);
>> +
>> + return ret;
>> +}
>> +
>> +/* Parse platform data */
>
> parse devicetree data ?

Yes, devicetree.

>
>> +static int sdhci_msm_populate_pdata(struct device *dev,
>> + struct sdhci_msm_pltfm_data *pdata)
>> +{
>> + struct device_node *np = dev->of_node;
>> + int len, i;
>> +
>> + if (sdhci_msm_dt_parse_vreg_info(dev, &pdata->vdd_data, "vdd")) {
>> + dev_err(dev, "failed parsing vdd data\n");
>> + return -EINVAL;
>> + }
>> + if (sdhci_msm_dt_parse_vreg_info(dev, &pdata->vdd_io_data, "vdd-io")) {
>> + dev_err(dev, "failed parsing vdd-io data\n");
>> + return -EINVAL;
>> + }
>> +
>> + len = of_property_count_strings(np, "qcom,bus-speed-mode");
>> +
>> + for (i = 0; i < len; i++) {
>> + const char *name = NULL;
>> +
>> + of_property_read_string_index(np,
>> + "qcom,bus-speed-mode", i, &name);
>> + if (!name)
>> + continue;
>> +
>> + if (!strncmp(name, "HS200_1p8v", sizeof("HS200_1p8v")))
>> + pdata->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
>> + else if (!strncmp(name, "HS200_1p2v", sizeof("HS200_1p2v")))
>> + pdata->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
>> + else if (!strncmp(name, "DDR_1p8v", sizeof("DDR_1p8v")))
>> + pdata->caps |= MMC_CAP_1_8V_DDR | MMC_CAP_UHS_DDR50;
>> + else if (!strncmp(name, "DDR_1p2v", sizeof("DDR_1p2v")))
>> + pdata->caps |= MMC_CAP_1_2V_DDR | MMC_CAP_UHS_DDR50;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +/* Regulator utility functions */
>> +static int sdhci_msm_vreg_init_reg(struct device *dev,
>> + struct sdhci_msm_reg_data *vreg)
>> +{
>> + int ret = 0;
>
> could you remove ret variable, please.

Ok.

>
>> + /* Get the regulator handle */
>
> useless comment

Ok.

>
>> + vreg->reg = devm_regulator_get(dev, vreg->name);
>> + if (IS_ERR(vreg->reg)) {
>> + ret = PTR_ERR(vreg->reg);
>> + dev_err(dev, "devm_regulator_get(%s) failed. ret=%d\n",
>> + vreg->name, ret);
>> + return ret;
>
> just return PTR_ERR(vreg->reg)

Ok.

>
>> + }
>> +
>> + /* sanity check */
>> + if (!vreg->high_vol_level || !vreg->hpm_uA) {
>
> if this is sanity check shouldn't you check low_vol_level and lpm_uA as
> well?

Yes, I'll improve it. Thanks!

>
>> + dev_err(dev, "%s invalid constraints specified\n", vreg->name);
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int sdhci_msm_vreg_enable(struct sdhci_msm_reg_data *vreg)
>> +{
>> + int ret = 0;
>> +
>> + /* Put regulator in HPM (high power mode) */
>> + ret = regulator_set_optimum_mode(vreg->reg, vreg->hpm_uA);
>> + if (ret < 0) {
>> + pr_err("regulator_set_optimum_mode(%s,uA_load=%d) fail (%d)\n",
>> + vreg->name, vreg->hpm_uA, ret);
>
> use dev_err() instead.

Ok.

>
>> + return ret;
>> + }
>> +
>> + if (!regulator_is_enabled(vreg->reg)) {
>> + /* Set voltage level */
>> + ret = regulator_set_voltage(vreg->reg, vreg->high_vol_level,
>> + vreg->high_vol_level);
>> + if (ret)
>> + return ret;
>> + }
>> +
>> + ret = regulator_enable(vreg->reg);
>> + if (ret) {
>> + pr_err("regulator_enable(%s) fail (%d)\n", vreg->name, ret);
>
> use dev_err().

Ok.

>
>> + return ret;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int sdhci_msm_vreg_disable(struct sdhci_msm_reg_data *vreg)
>> +{
>> + int ret = 0;
>
> IMO no need to initialize ret variable?

Agree.

>
>> +
>> + if (!regulator_is_enabled(vreg->reg))
>> + return 0;
>> +
>> + /* Never disable regulator marked as always_on */
>> + if (vreg->is_always_on) {
>> + if (vreg->lpm_sup) {
>> + /* Put always_on regulator in LPM (low power mode) */
>> + ret = regulator_set_optimum_mode(vreg->reg,
>> + vreg->lpm_uA);
>> + if (ret < 0)
>> + return ret;
>> + }
>> + } else {
>> + ret = regulator_disable(vreg->reg);
>> + if (ret) {
>> + pr_err("regulator_disable(%s) fail (%d)\n",
>> + vreg->name, ret);
>
> dev_err(), please.

Ok.

>
>> + return ret;
>> + }
>> +
>> + ret = regulator_set_optimum_mode(vreg->reg, 0);
>> + if (ret < 0)
>> + return ret;
>> +
>> + /* Set min. voltage level to 0 */
>> + ret = regulator_set_voltage(vreg->reg, 0, vreg->high_vol_level);
>> + if (ret)
>> + return ret;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int sdhci_msm_setup_vreg(struct sdhci_msm_pltfm_data *pdata,
>> + bool enable, bool is_init)
>> +{
>> + int ret = 0, i;
>
> no need to initialize ret variable?

Agree.

>
>> + struct sdhci_msm_reg_data *vreg_table[2];
>> +
>> + vreg_table[0] = &pdata->vdd_data;
>> + vreg_table[1] = &pdata->vdd_io_data;
>> +
>> + for (i = 0; i < ARRAY_SIZE(vreg_table); i++) {
>> + if (vreg_table[i]) {
>
> could you invert the logic here:
>
> if (!vreg_table[i])
> continue;
>
> by that way you will save one tab below.

Yes, thanks!

>
>> + if (enable)
>> + ret = sdhci_msm_vreg_enable(vreg_table[i]);
>> + else
>> + ret = sdhci_msm_vreg_disable(vreg_table[i]);
>> + if (ret)
>> + return ret;
>> + }
>> + }
>
> blank line ?

Ok.

>
>> + return 0;
>> +}
>> +
>> +/* This init function should be called only once for each SDHC slot */
>> +static int sdhci_msm_vreg_init(struct device *dev,
>> + struct sdhci_msm_pltfm_data *pdata)
>> +{
>> + struct sdhci_msm_reg_data *curr_vdd_reg = &pdata->vdd_data;
>> + struct sdhci_msm_reg_data *curr_vdd_io_reg = &pdata->vdd_io_data;
>> + int ret = 0;
>
> no need to initialize ret variable.

Agree.

>
>> +
>> + ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_reg);
>> + if (ret)
>> + return ret;
>> +
>> + ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_io_reg);
>> + if (ret)
>> + return ret;
>> +
>> + return 0;
>> +}
>> +
>> +static int sdhci_msm_set_vdd_io_vol(struct sdhci_msm_pltfm_data *pdata,
>> + enum vdd_io_level level,
>> + unsigned int voltage_level)
>> +{
>> + int set_level;
>> + struct sdhci_msm_reg_data *vdd_io_reg = &pdata->vdd_io_data;
>> +
>> + if (!regulator_is_enabled(vdd_io_reg->reg))
>> + return 0;
>> +
>> + switch (level) {
>> + case VDD_IO_LOW:
>> + set_level = vdd_io_reg->low_vol_level;
>> + break;
>> + case VDD_IO_HIGH:
>> + set_level = vdd_io_reg->high_vol_level;
>> + break;
>> + case VDD_IO_SET_LEVEL:
>> + set_level = voltage_level;
>> + break;
>> + default:
>> + pr_err("invalid vdd_io level = %d", level);
>> + return -EINVAL;
>> + }
>
> add blank line here, please.

Ok.

>
>> + return regulator_set_voltage(vdd_io_reg->reg, set_level, set_level);
>> +}
>> +
>> +static irqreturn_t sdhci_msm_pwr_irq(int irq, void *data)
>> +{
>> + struct sdhci_msm_host *msm_host = (struct sdhci_msm_host *)data;
>> + u8 irq_status = 0;
>> + u8 irq_ack = 0;
>> + int ret = 0;
>
> no need to initialize irq_status and ret, right?

Agree.

>
>> +
>> + irq_status = readb_relaxed(msm_host->core_mem + CORE_PWRCTL_STATUS);
>> + pr_debug("%s: Received IRQ(%d), status=0x%x\n",
>> + mmc_hostname(msm_host->mmc), irq, irq_status);
>
> dev_dbg() ?

Ok.

>
>> +
>> + /* Clear the interrupt */
>> + writeb_relaxed(irq_status, (msm_host->core_mem + CORE_PWRCTL_CLEAR));
>
> why you use writeb here, but in .probe you use writel?

From the limited documentation I have, it seems that only 4 bits from
these registers are defined and used, so I prefer to keep it this way.

>
>> + /*
>> + * SDHC has core_mem and hc_mem device memory and these memory
>> + * addresses do not fall within 1KB region. Hence, any update to
>> + * core_mem address space would require an mb() to ensure this gets
>> + * completed before its next update to registers within hc_mem.
>> + */
>> + mb();
>> +
>> + /* Handle BUS ON/OFF */
>> + if (irq_status & (CORE_PWRCTL_BUS_ON | CORE_PWRCTL_BUS_OFF)) {
>> + bool flag = (irq_status & CORE_PWRCTL_BUS_ON) ? 1 : 0;
>> + ret = sdhci_msm_setup_vreg(&msm_host->pdata, flag, false);
>> + if (ret)
>> + irq_ack |= CORE_PWRCTL_BUS_FAIL;
>> + else
>> + irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
>> + }
>> + /* Handle IO LOW/HIGH */
>> + if (irq_status & (CORE_PWRCTL_IO_LOW | CORE_PWRCTL_IO_HIGH)) {
>> + /* Switch voltage */
>> + int io_status = (irq_status & CORE_PWRCTL_IO_LOW) ?
>> + VDD_IO_LOW : VDD_IO_HIGH;
>> + ret = sdhci_msm_set_vdd_io_vol(&msm_host->pdata, io_status, 0);
>> + if (ret)
>> + irq_ack |= CORE_PWRCTL_IO_FAIL;
>> + else
>> + irq_ack |= CORE_PWRCTL_IO_SUCCESS;
>> + }
>> +
>> + /* ACK status to the core */
>> + writeb_relaxed(irq_ack, (msm_host->core_mem + CORE_PWRCTL_CTL));
>> + /*
>> + * SDHC has core_mem and hc_mem device memory and these memory
>> + * addresses do not fall within 1KB region. Hence, any update to
>> + * core_mem address space would require an mb() to ensure this gets
>> + * completed before its next update to registers within hc_mem.
>> + */
>> + mb();
>> +
>> + pr_debug("%s: Handled IRQ(%d), ret=%d, ack=0x%x\n",
>> + mmc_hostname(msm_host->mmc), irq, ret, irq_ack);
>
> dev_dbg() ?

Ok.

>
>> + return IRQ_HANDLED;
>> +}
>> +
>> +/* This function returns the max. current supported by VDD rail in mA */
>> +static u32 sdhci_msm_get_vdd_max_current(struct sdhci_msm_host *host)
>> +{
>> + return host->pdata.vdd_data.hpm_uA / 1000;
>> +}
>> +
>> +static const struct of_device_id sdhci_msm_dt_match[] = {
>> + {.compatible = "qcom,sdhci-msm"},
>> + {},
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, sdhci_msm_dt_match);
>> +
>> +static int sdhci_msm_probe(struct platform_device *pdev)
>> +{
>> + struct sdhci_host *host;
>> + struct sdhci_pltfm_host *pltfm_host;
>> + struct sdhci_msm_host *msm_host;
>> + struct resource *core_memres = NULL;
>> + int ret = 0, dead = 0;
>
> no need to initialize ret and dead variables.

Agree.

>
>> + struct pinctrl *pinctrl;
>> +
>> + if (!pdev->dev.of_node) {
>> + dev_err(&pdev->dev, "No device tree data\n");
>> + return -ENOENT;
>> + }
>> +
>> + msm_host = devm_kzalloc(&pdev->dev, sizeof(*msm_host), GFP_KERNEL);
>> + if (!msm_host)
>> + return -ENOMEM;
>> +
>> + host = sdhci_pltfm_init(pdev, &msm_host->sdhci_msm_pdata, 0);
>> + if (IS_ERR(host)) {
>> + dev_err(mmc_dev(host->mmc), "sdhci_pltfm_init error\n");
>> + return PTR_ERR(host);
>> + }
>> +
>> + pltfm_host = sdhci_priv(host);
>> + pltfm_host->priv = msm_host;
>> + msm_host->mmc = host->mmc;
>> + msm_host->pdev = pdev;
>> +
>> + ret = mmc_of_parse(host->mmc);
>> + if (ret) {
>> + dev_err(&pdev->dev, "failed parsing mmc device tree\n");
>> + goto pltfm_free;
>> + }
>> +
>> + /* Extract platform data */
>
> needless comment, again.
>

Ok.

>> + ret = sdhci_msm_populate_pdata(&pdev->dev, &msm_host->pdata);
>> + if (ret) {
>> + dev_err(&pdev->dev, "DT parsing error\n");
>> + goto pltfm_free;
>> + }
>> +
>> + /* Setup pins */
>> + pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
>> + if (IS_ERR(pinctrl))
>> + dev_warn(&pdev->dev, "pins are not configured by the driver\n");
>> +
>> + /* Setup SDCC bus voter clock. */
>> + msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus");
>> + if (!IS_ERR(msm_host->bus_clk)) {
>> + /* Vote for max. clk rate for max. performance */
>> + ret = clk_set_rate(msm_host->bus_clk, INT_MAX);
>> + if (ret)
>> + goto pltfm_free;
>> + ret = clk_prepare_enable(msm_host->bus_clk);
>> + if (ret)
>> + goto pltfm_free;
>> + }
>> +
>> + /* Setup main peripheral bus clock */
>> + msm_host->pclk = devm_clk_get(&pdev->dev, "iface");
>> + if (!IS_ERR(msm_host->pclk)) {
>> + ret = clk_prepare_enable(msm_host->pclk);
>> + if (ret) {
>> + dev_err(&pdev->dev,
>> + "Main peripheral clock setup failed (%d)\n",
>> + ret);
>> + goto bus_clk_disable;
>> + }
>> + }
>> +
>> + /* Setup SDC MMC clock */
>> + msm_host->clk = devm_clk_get(&pdev->dev, "core");
>> + if (IS_ERR(msm_host->clk)) {
>> + ret = PTR_ERR(msm_host->clk);
>> + dev_err(&pdev->dev, "SDC MMC clock setup failed (%d)\n", ret);
>> + goto pclk_disable;
>> + }
>> +
>> + ret = clk_prepare_enable(msm_host->clk);
>> + if (ret)
>> + goto pclk_disable;
>> +
>> + /* Setup regulators */
>> + ret = sdhci_msm_vreg_init(&pdev->dev, &msm_host->pdata);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Regulator setup failed (%d)\n", ret);
>> + goto clk_disable;
>> + }
>> +
>> + /* Reset the core and Enable SDHC mode */
>
> this comment should go few lines below.
>

Ok.

>> + core_memres = platform_get_resource_byname(pdev,
>> + IORESOURCE_MEM, "core_mem");
>> + msm_host->core_mem = devm_ioremap_resource(&pdev->dev, core_memres);
>> +
>> + if (IS_ERR(msm_host->core_mem)) {
>> + dev_err(&pdev->dev, "Failed to remap registers\n");
>> + ret = PTR_ERR(msm_host->core_mem);
>> + goto vreg_disable;
>> + }
>> +
>> + /* Set SW_RST bit in POWER register (Offset 0x0) */
>
> those comments are stupid, please remove them.
>

Ok.

>> + writel_relaxed(CORE_SW_RST, msm_host->core_mem + CORE_POWER);
>> + /* Set HC_MODE_EN bit in HC_MODE register */
>> + writel_relaxed(HC_MODE_EN, (msm_host->core_mem + CORE_HC_MODE));
>> +
>
> are all interrupts disabled at this point?
>

Yes, they are enabled later.

>> + /*
>> + * Following are the deviations from SDHC spec v3.0 -
>> + * 1. Card detection is handled using separate GPIO.
>> + * 2. Bus power control is handled by interacting with PMIC.
>> + */
>> + host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
>> +
>> + /* Setup PWRCTL irq */
>> + msm_host->pwr_irq = platform_get_irq_byname(pdev, "pwr_irq");
>> + if (msm_host->pwr_irq < 0) {
>> + dev_err(&pdev->dev, "Failed to get pwr_irq by name (%d)\n",
>> + msm_host->pwr_irq);
>> + goto vreg_disable;
>> + }
>> + ret = devm_request_threaded_irq(&pdev->dev, msm_host->pwr_irq, NULL,
>> + sdhci_msm_pwr_irq, IRQF_ONESHOT,
>> + dev_name(&pdev->dev), host);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Request threaded irq(%d) failed (%d)\n",
>> + msm_host->pwr_irq, ret);
>> + goto vreg_disable;
>> + }
>> +
>> + /* Enable pwr irq interrupts */
>> + writel_relaxed(INT_MASK, (msm_host->core_mem + CORE_PWRCTL_MASK));
>> +
>> + /* Set host capabilities */
>
> useless comment
>

Ok. I'll remove it.

>> + msm_host->mmc->caps |= msm_host->pdata.caps;
>> + msm_host->mmc->caps2 |= msm_host->pdata.caps2;
>> +
>> + ret = sdhci_add_host(host);
>> + if (ret) {
>> + dev_err(&pdev->dev, "Add host failed (%d)\n", ret);
>> + goto vreg_disable;
>> + }
>> +
>> + /* Set core clk rate */
>
> useless comment
>

Ok.

>> + ret = clk_set_rate(msm_host->clk, host->max_clk);
>> + if (ret) {
>> + dev_err(&pdev->dev, "MClk rate set failed (%d)\n", ret);
>> + goto remove_host;
>> + }
>> +
>> + host->mmc->max_current_180 = host->mmc->max_current_300 =
>> + host->mmc->max_current_330 = sdhci_msm_get_vdd_max_current(msm_host);
>> +
>> + /* Successful initialization */
>
> useless comment
>

Ok.

>> + return 0;
>> +
>> +remove_host:
>> + dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
>> + sdhci_remove_host(host, dead);
>> +vreg_disable:
>> + if (!IS_ERR(msm_host->pdata.vdd_data.reg))
>> + sdhci_msm_vreg_disable(&msm_host->pdata.vdd_data);
>> + if (!IS_ERR(msm_host->pdata.vdd_io_data.reg))
>> + sdhci_msm_vreg_disable(&msm_host->pdata.vdd_io_data);
>> +clk_disable:
>> + if (!IS_ERR(msm_host->clk))
>> + clk_disable_unprepare(msm_host->clk);
>> +pclk_disable:
>> + if (!IS_ERR(msm_host->pclk))
>> + clk_disable_unprepare(msm_host->pclk);
>> +bus_clk_disable:
>> + if (!IS_ERR(msm_host->bus_clk))
>> + clk_disable_unprepare(msm_host->bus_clk);
>> +pltfm_free:
>> + sdhci_pltfm_free(pdev);
>> + return ret;
>> +}
>> +
>> +static int sdhci_msm_remove(struct platform_device *pdev)
>> +{
>> + struct sdhci_host *host = platform_get_drvdata(pdev);
>> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>> + struct sdhci_msm_host *msm_host = pltfm_host->priv;
>> + int dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) ==
>> + 0xffffffff);
>> +
>> + sdhci_remove_host(host, dead);
>> + sdhci_pltfm_free(pdev);
>> + sdhci_msm_vreg_disable(&msm_host->pdata.vdd_data);
>> + sdhci_msm_vreg_disable(&msm_host->pdata.vdd_io_data);
>> + clk_disable_unprepare(msm_host->clk);
>> + clk_disable_unprepare(msm_host->pclk);
>> + if (!IS_ERR(msm_host->bus_clk))
>> + clk_disable_unprepare(msm_host->bus_clk);
>> + return 0;
>> +}
>> +
>> +static struct platform_driver sdhci_msm_driver = {
>> + .probe = sdhci_msm_probe,
>> + .remove = sdhci_msm_remove,
>> + .driver = {
>> + .name = "sdhci_msm",
>> + .owner = THIS_MODULE,
>> + .of_match_table = sdhci_msm_dt_match,
>> + },
>
> this bracket should be under ".driver".

Ok. Thanks!

BR,
Georgi