2013-09-12 14:55:55

by Georgi Djakov

[permalink] [raw]
Subject: [PATCH v4] 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 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 | 660 ++++++++++++++++++++
4 files changed, 745 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 b7fd5ab..b2a1fdb 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..904158d
--- /dev/null
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -0,0 +1,660 @@
+/*
+ * 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);
+ ret = -EINVAL;
+ return ret;
+ }
+
+ if (!vreg) {
+ dev_err(dev, "invalid vreg: %s\n", vreg_name);
+ ret = -EINVAL;
+ return ret;
+ }
+
+ 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 %s vol=[%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 (!pdata) {
+ dev_err(dev, "invalid platform data\n");
+ return -EINVAL;
+ }
+
+ 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;
+
+ /* check if regulator is already initialized? */
+ if (!IS_ERR(vreg->reg))
+ return ret;
+
+ /* 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 ret;
+}
+
+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
+ ("%s: regulator_set_optimum_mode(%s,uA_load=%d) fail(%d)\n",
+ __func__, 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("%s: regulator_enable(%s) failed. ret=%d\n",
+ __func__, vreg->name, ret);
+ return ret;
+ }
+ return ret;
+}
+
+static int sdhci_msm_vreg_disable(struct sdhci_msm_reg_data *vreg)
+{
+ int ret = 0;
+
+ /* Never disable regulator marked as always_on */
+ if (regulator_is_enabled(vreg->reg) && !vreg->is_always_on) {
+ ret = regulator_disable(vreg->reg);
+ if (ret) {
+ pr_err("%s: regulator_disable(%s) failed. ret=%d\n",
+ __func__, 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;
+ } else if (regulator_is_enabled(vreg->reg) && 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;
+ }
+ }
+
+ return ret;
+}
+
+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 ret;
+}
+
+/* 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, bool is_init)
+{
+ int ret = 0;
+ struct sdhci_msm_reg_data *curr_vdd_reg, *curr_vdd_io_reg;
+
+ curr_vdd_reg = &pdata->vdd_data;
+ curr_vdd_io_reg = &pdata->vdd_io_data;
+
+ if (!is_init)
+ /* Deregister all regulators from regulator framework */
+ return ret;
+
+ /*
+ * Get the regulator handle from voltage regulator framework
+ * and then try to set the voltage level for the regulator
+ */
+ if (curr_vdd_reg) {
+ ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_reg);
+ if (ret)
+ return ret;
+ }
+ if (curr_vdd_io_reg) {
+ ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_io_reg);
+ if (ret)
+ return ret;
+ }
+
+ return ret;
+}
+
+static int sdhci_msm_set_vdd_io_vol(struct sdhci_msm_pltfm_data *pdata,
+ enum vdd_io_level level,
+ unsigned int voltage_level)
+{
+ int ret = 0;
+ int set_level;
+ struct sdhci_msm_reg_data *vdd_io_reg = &pdata->vdd_io_data;
+
+ if (vdd_io_reg && regulator_is_enabled(vdd_io_reg->reg)) {
+ 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("%s: invalid argument level = %d",
+ __func__, level);
+ return -EINVAL;
+ }
+ ret = regulator_set_voltage(vdd_io_reg->reg,
+ set_level, set_level);
+ }
+
+ return ret;
+}
+
+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)
+{
+ struct sdhci_msm_pltfm_data pdata = host->pdata;
+ return 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;
+
+ 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 */
+ if (pdev->dev.of_node) {
+ ret = sdhci_msm_populate_pdata(&pdev->dev, &msm_host->pdata);
+ if (ret) {
+ dev_err(&pdev->dev, "DT parsing error\n");
+ goto pltfm_free;
+ }
+ } else {
+ dev_err(&pdev->dev, "No device tree node\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 Clocks */
+
+ /* Setup SDCC bus voter clock. */
+ msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus");
+ if (!IS_ERR_OR_NULL(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, true);
+ 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(&pdev->dev, core_memres->start,
+ resource_size(core_memres));
+
+ if (!msm_host->core_mem) {
+ dev_err(&pdev->dev, "Failed to remap registers\n");
+ ret = -ENOMEM;
+ goto vreg_deinit;
+ }
+
+ /* 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_deinit;
+ }
+ 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_deinit;
+ }
+
+ /* 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_deinit;
+ }
+
+ /* 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 */
+ goto out;
+
+remove_host:
+ dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
+ sdhci_remove_host(host, dead);
+vreg_deinit:
+ sdhci_msm_vreg_init(&pdev->dev, &msm_host->pdata, false);
+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_OR_NULL(msm_host->bus_clk))
+ clk_disable_unprepare(msm_host->bus_clk);
+pltfm_free:
+ sdhci_pltfm_free(pdev);
+out:
+ 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);
+
+ pr_debug("%s: %s\n", dev_name(&pdev->dev), __func__);
+ sdhci_remove_host(host, dead);
+ sdhci_pltfm_free(pdev);
+ sdhci_msm_vreg_init(&pdev->dev, &msm_host->pdata, false);
+ clk_disable_unprepare(msm_host->clk);
+ clk_disable_unprepare(msm_host->pclk);
+ if (!IS_ERR_OR_NULL(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


2013-09-13 12:18:44

by Ivan T. Ivanov

[permalink] [raw]
Subject: Re: [PATCH v4] mmc: sdhci-msm: Add support for MSM chipsets


Hi Georgi,

Several comments bellow.

On Thu, 2013-09-12 at 17:56 +0300, 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 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 | 660 ++++++++++++++++++++
> 4 files changed, 745 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 b7fd5ab..b2a1fdb 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..904158d
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -0,0 +1,660 @@
> +/*
> + * 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);
> + ret = -EINVAL;
> + return ret;

Just return -EINVAL?

> + }
> +
> + if (!vreg) {

This could not happen, right?

> + dev_err(dev, "invalid vreg: %s\n", vreg_name);
> + ret = -EINVAL;
> + return ret;
> + }
> +
> + 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 %s vol=[%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 (!pdata) {

This could not be null

> + dev_err(dev, "invalid platform data\n");
> + return -EINVAL;
> + }
> +
> + 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;
> +
> + /* check if regulator is already initialized? */
> + if (!IS_ERR(vreg->reg))

This couldn't happen, right?

> + return ret;
> +
> + /* 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 ret;
> +}
> +
> +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
> + ("%s: regulator_set_optimum_mode(%s,uA_load=%d) fail(%d)\n",
> + __func__, 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("%s: regulator_enable(%s) failed. ret=%d\n",
> + __func__, vreg->name, ret);
> + return ret;
> + }
> + return ret;
> +}
> +
> +static int sdhci_msm_vreg_disable(struct sdhci_msm_reg_data *vreg)
> +{
> + int ret = 0;
> +
> + /* Never disable regulator marked as always_on */
> + if (regulator_is_enabled(vreg->reg) && !vreg->is_always_on) {
> + ret = regulator_disable(vreg->reg);
> + if (ret) {
> + pr_err("%s: regulator_disable(%s) failed. ret=%d\n",
> + __func__, vreg->name, ret);

The __func__ did not bring any useful information. Please, just use
meaningful error messages.

> + 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;
> + } else if (regulator_is_enabled(vreg->reg) && 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;
> + }
> + }
> +

You could check for !regulator_is_enabled(vreg->reg) at the beginning
of the function and exit immediately.

> + return ret;
> +}
> +
> +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 ret;
> +}
> +
> +/* 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, bool is_init)
> +{
> + int ret = 0;
> + struct sdhci_msm_reg_data *curr_vdd_reg, *curr_vdd_io_reg;
> +
> + curr_vdd_reg = &pdata->vdd_data;
> + curr_vdd_io_reg = &pdata->vdd_io_data;
> +
> + if (!is_init)

Redundant parameter?

> + /* Deregister all regulators from regulator framework */
> + return ret;
> +
> + /*
> + * Get the regulator handle from voltage regulator framework
> + * and then try to set the voltage level for the regulator
> + */
> + if (curr_vdd_reg) {

This is always true

> + ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_reg);
> + if (ret)
> + return ret;
> + }
> + if (curr_vdd_io_reg) {

Same here.

> + ret = sdhci_msm_vreg_init_reg(dev, curr_vdd_io_reg);
> + if (ret)
> + return ret;
> + }
> +
> + return ret;
> +}
> +
> +static int sdhci_msm_set_vdd_io_vol(struct sdhci_msm_pltfm_data *pdata,
> + enum vdd_io_level level,
> + unsigned int voltage_level)
> +{
> + int ret = 0;
> + int set_level;
> + struct sdhci_msm_reg_data *vdd_io_reg = &pdata->vdd_io_data;
> +
> + if (vdd_io_reg && regulator_is_enabled(vdd_io_reg->reg)) {
> + 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("%s: invalid argument level = %d",
> + __func__, level);
> + return -EINVAL;
> + }
> + ret = regulator_set_voltage(vdd_io_reg->reg,
> + set_level, set_level);
> + }
> +
> + return ret;
> +}
> +
> +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)
> +{
> + struct sdhci_msm_pltfm_data pdata = host->pdata;

Probably I want to use pointer here.

> + return 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;
> +
> + 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 */
> + if (pdev->dev.of_node) {
> + ret = sdhci_msm_populate_pdata(&pdev->dev, &msm_host->pdata);
> + if (ret) {
> + dev_err(&pdev->dev, "DT parsing error\n");
> + goto pltfm_free;
> + }
> + } else {
> + dev_err(&pdev->dev, "No device tree node\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 Clocks */
> +
> + /* Setup SDCC bus voter clock. */
> + msm_host->bus_clk = devm_clk_get(&pdev->dev, "bus");
> + if (!IS_ERR_OR_NULL(msm_host->bus_clk)) {

Use only IS_ERR.

> + /* 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, true);
> + 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(&pdev->dev, core_memres->start,
> + resource_size(core_memres));

You could use devm_ioremap_resource()

> +
> + if (!msm_host->core_mem) {
> + dev_err(&pdev->dev, "Failed to remap registers\n");
> + ret = -ENOMEM;
> + goto vreg_deinit;
> + }
> +
> + /* 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_deinit;
> + }
> + 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_deinit;
> + }
> +
> + /* 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_deinit;
> + }
> +
> + /* 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 */
> + goto out;

return 0?

> +
> +remove_host:
> + dead = (readl_relaxed(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
> + sdhci_remove_host(host, dead);
> +vreg_deinit:
> + sdhci_msm_vreg_init(&pdev->dev, &msm_host->pdata, false);
> +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_OR_NULL(msm_host->bus_clk))

Just IS_ERR.

> + clk_disable_unprepare(msm_host->bus_clk);
> +pltfm_free:
> + sdhci_pltfm_free(pdev);
> +out:
> + 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);
> +
> + pr_debug("%s: %s\n", dev_name(&pdev->dev), __func__);
> + sdhci_remove_host(host, dead);
> + sdhci_pltfm_free(pdev);
> + sdhci_msm_vreg_init(&pdev->dev, &msm_host->pdata, false);

This is no longer required, right? But still regulators have to be
disabled.

> + clk_disable_unprepare(msm_host->clk);
> + clk_disable_unprepare(msm_host->pclk);
> + if (!IS_ERR_OR_NULL(msm_host->bus_clk))

Just IS_ERR.

Thanks,
Ivan

> + 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");