2021-09-25 06:46:46

by Cai,Huoqing

[permalink] [raw]
Subject: [PATCH v6 1/3] iio: imx8qxp-adc: Add driver support for NXP IMX8QXP ADC

The NXP i.MX 8QuadXPlus SOC has a new ADC IP, so add
driver support for this ADC.

Signed-off-by: Cai Huoqing <[email protected]>
---
v1->v2:
*Squash patches 1, 2, 3, and 5 into a single patch.
*Add device specific prefix.
*Remove the brackets around individual numbers.
*Make use of FIELD_PREP() and FIELD_GET().
*Remove a lot of cache values.
*Replace mlock with adc->lock.
*Move adc->value read from isr to the completion.
*Set pm_runtime_disable/_put_noidle() before adc_disable.
*Add error handler-err_disable_reg/err_unprepare_clk.
v2->v3:
*Add "return 0" to adc_runtime_resume().
v3->v4:
*Sort header file declarations in alphabetical order.
*Remove explicitly cast from "void *".
*Make use of dev_err_probe().
*Add some blank lines to help readability.
v4->v5:
*Update commit message.
*Remove unused headers.
*Wrap imx8qxp_adc_read_raw() at a shorter line length that helps readability.
*Deal with clock/regulator in probe/remove().
*Use ADC_DRIVER_NAME instead of dev_name(dev).
*Don't use dev_error_probe() without returning -PROBE_DEFER.
v5->v6:
*Rename the error path labels to indicate the action that will be performed.

v1 link:
https://patchwork.kernel.org/project/linux-arm-kernel/patch/[email protected]/
v3 link:
https://patchwork.kernel.org/project/linux-arm-kernel/patch/[email protected]/
v4 link:
https://patchwork.kernel.org/project/linux-arm-kernel/patch/[email protected]/
v5 link:
https://patchwork.kernel.org/project/linux-arm-kernel/patch/[email protected]/

drivers/iio/adc/Kconfig | 10 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/imx8qxp-adc.c | 494 ++++++++++++++++++++++++++++++++++
3 files changed, 505 insertions(+)
create mode 100644 drivers/iio/adc/imx8qxp-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index af168e1c9fdb..fa8ad63d6ac2 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -530,6 +530,16 @@ config IMX7D_ADC
This driver can also be built as a module. If so, the module will be
called imx7d_adc.

+config IMX8QXP_ADC
+ tristate "NXP IMX8QXP ADC driver"
+ depends on ARCH_MXC_ARM64 || COMPILE_TEST
+ depends on HAS_IOMEM
+ help
+ Say yes here to build support for IMX8QXP ADC.
+
+ This driver can also be built as a module. If so, the module will be
+ called imx8qxp-adc.
+
config LP8788_ADC
tristate "LP8788 ADC driver"
depends on MFD_LP8788
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index d68550f493e3..d3f53549720c 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_FSL_MX25_ADC) += fsl-imx25-gcq.o
obj-$(CONFIG_HI8435) += hi8435.o
obj-$(CONFIG_HX711) += hx711.o
obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
+obj-$(CONFIG_IMX8QXP_ADC) += imx8qxp-adc.o
obj-$(CONFIG_INA2XX_ADC) += ina2xx-adc.o
obj-$(CONFIG_INGENIC_ADC) += ingenic-adc.o
obj-$(CONFIG_INTEL_MRFLD_ADC) += intel_mrfld_adc.o
diff --git a/drivers/iio/adc/imx8qxp-adc.c b/drivers/iio/adc/imx8qxp-adc.c
new file mode 100644
index 000000000000..c52b1777fa30
--- /dev/null
+++ b/drivers/iio/adc/imx8qxp-adc.c
@@ -0,0 +1,494 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * NXP i.MX8QXP ADC driver
+ *
+ * Based on the work of Haibo Chen <[email protected]>
+ * The initial developer of the original code is Haibo Chen.
+ * Portions created by Haibo Chen are Copyright (C) 2018 NXP.
+ * All Rights Reserved.
+ *
+ * Copyright (C) 2018 NXP
+ * Copyright (C) 2021 Cai Huoqing
+ */
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+
+#include <linux/iio/iio.h>
+
+#define ADC_DRIVER_NAME "imx8qxp-adc"
+
+/* Register map definition */
+#define IMX8QXP_ADR_ADC_CTRL 0x10
+#define IMX8QXP_ADR_ADC_STAT 0x14
+#define IMX8QXP_ADR_ADC_IE 0x18
+#define IMX8QXP_ADR_ADC_DE 0x1c
+#define IMX8QXP_ADR_ADC_CFG 0x20
+#define IMX8QXP_ADR_ADC_FCTRL 0x30
+#define IMX8QXP_ADR_ADC_SWTRIG 0x34
+#define IMX8QXP_ADR_ADC_TCTRL(tid) (0xc0 + tid * 4)
+#define IMX8QXP_ADR_ADC_CMDH(cid) (0x100 + cid * 8)
+#define IMX8QXP_ADR_ADC_CMDL(cid) (0x104 + cid * 8)
+#define IMX8QXP_ADR_ADC_RESFIFO 0x300
+#define IMX8QXP_ADR_ADC_TST 0xffc
+
+/* ADC bit shift */
+#define IMX8QXP_ADC_IE_FWMIE_MASK GENMASK(1, 0)
+#define IMX8QXP_ADC_CTRL_FIFO_RESET_MASK BIT(8)
+#define IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK BIT(1)
+#define IMX8QXP_ADC_CTRL_ADC_EN_MASK BIT(0)
+#define IMX8QXP_ADC_TCTRL_TCMD_MASK GENMASK(31, 24)
+#define IMX8QXP_ADC_TCTRL_TDLY_MASK GENMASK(23, 16)
+#define IMX8QXP_ADC_TCTRL_TPRI_MASK GENMASK(15, 8)
+#define IMX8QXP_ADC_TCTRL_HTEN_MASK GENMASK(7, 0)
+#define IMX8QXP_ADC_CMDL_CSCALE_MASK GENMASK(13, 8)
+#define IMX8QXP_ADC_CMDL_MODE_MASK BIT(7)
+#define IMX8QXP_ADC_CMDL_DIFF_MASK BIT(6)
+#define IMX8QXP_ADC_CMDL_ABSEL_MASK BIT(5)
+#define IMX8QXP_ADC_CMDL_ADCH_MASK GENMASK(2, 0)
+#define IMX8QXP_ADC_CMDH_NEXT_MASK GENMASK(31, 24)
+#define IMX8QXP_ADC_CMDH_LOOP_MASK GENMASK(23, 16)
+#define IMX8QXP_ADC_CMDH_AVGS_MASK GENMASK(15, 12)
+#define IMX8QXP_ADC_CMDH_STS_MASK BIT(8)
+#define IMX8QXP_ADC_CMDH_LWI_MASK GENMASK(7, 7)
+#define IMX8QXP_ADC_CMDH_CMPEN_MASK GENMASK(0, 0)
+#define IMX8QXP_ADC_CFG_PWREN_MASK BIT(28)
+#define IMX8QXP_ADC_CFG_PUDLY_MASK GENMASK(23, 16)
+#define IMX8QXP_ADC_CFG_REFSEL_MASK GENMASK(7, 6)
+#define IMX8QXP_ADC_CFG_PWRSEL_MASK GENMASK(5, 4)
+#define IMX8QXP_ADC_CFG_TPRICTRL_MASK GENMASK(3, 0)
+#define IMX8QXP_ADC_FCTRL_FWMARK_MASK GENMASK(20, 16)
+#define IMX8QXP_ADC_FCTRL_FCOUNT_MASK GENMASK(4, 0)
+#define IMX8QXP_ADC_RESFIFO_VAL_MASK GENMASK(18, 3)
+
+/* ADC PARAMETER*/
+#define IMX8QXP_ADC_CMDL_CHANNEL_SCALE_FULL GENMASK(5, 0)
+#define IMX8QXP_ADC_CMDL_SEL_A_A_B_CHANNEL 0
+#define IMX8QXP_ADC_CMDL_STANDARD_RESOLUTION 0
+#define IMX8QXP_ADC_CMDL_MODE_SINGLE 0
+#define IMX8QXP_ADC_CMDH_LWI_INCREMENT_DIS 0
+#define IMX8QXP_ADC_CMDH_CMPEN_DIS 0
+#define IMX8QXP_ADC_PAUSE_EN BIT(31)
+#define IMX8QXP_ADC_TCTRL_TPRI_PRIORITY_HIGH 0
+
+#define IMX8QXP_ADC_TCTRL_HTEN_HW_TIRG_DIS 0
+
+#define IMX8QXP_ADC_TIMEOUT msecs_to_jiffies(100)
+
+struct imx8qxp_adc {
+ struct device *dev;
+ void __iomem *regs;
+ struct clk *clk;
+ struct clk *ipg_clk;
+ struct regulator *vref;
+ struct mutex lock;
+ struct completion completion;
+};
+
+#define IMX8QXP_ADC_CHAN(_idx) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = (_idx), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+}
+
+static const struct iio_chan_spec imx8qxp_adc_iio_channels[] = {
+ IMX8QXP_ADC_CHAN(0),
+ IMX8QXP_ADC_CHAN(1),
+ IMX8QXP_ADC_CHAN(2),
+ IMX8QXP_ADC_CHAN(3),
+ IMX8QXP_ADC_CHAN(4),
+ IMX8QXP_ADC_CHAN(5),
+ IMX8QXP_ADC_CHAN(6),
+ IMX8QXP_ADC_CHAN(7),
+};
+
+static void imx8qxp_adc_reset(struct imx8qxp_adc *adc)
+{
+ u32 ctrl;
+
+ /*software reset, need to clear the set bit*/
+ ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
+ ctrl |= FIELD_PREP(IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK, 1);
+ writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
+ udelay(10);
+ ctrl &= ~FIELD_PREP(IMX8QXP_ADC_CTRL_SOFTWARE_RESET_MASK, 1);
+ writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
+
+ /* reset the fifo */
+ ctrl |= FIELD_PREP(IMX8QXP_ADC_CTRL_FIFO_RESET_MASK, 1);
+ writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
+}
+
+static void imx8qxp_adc_reg_config(struct imx8qxp_adc *adc, int channel)
+{
+ u32 adc_cfg, adc_tctrl, adc_cmdl, adc_cmdh;
+
+ /* ADC configuration */
+ adc_cfg = FIELD_PREP(IMX8QXP_ADC_CFG_PWREN_MASK, 1) |
+ FIELD_PREP(IMX8QXP_ADC_CFG_PUDLY_MASK, 0x80)|
+ FIELD_PREP(IMX8QXP_ADC_CFG_REFSEL_MASK, 0) |
+ FIELD_PREP(IMX8QXP_ADC_CFG_PWRSEL_MASK, 3) |
+ FIELD_PREP(IMX8QXP_ADC_CFG_TPRICTRL_MASK, 0);
+ writel(adc_cfg, adc->regs + IMX8QXP_ADR_ADC_CFG);
+
+ /* config the trigger control */
+ adc_tctrl = FIELD_PREP(IMX8QXP_ADC_TCTRL_TCMD_MASK, 1) |
+ FIELD_PREP(IMX8QXP_ADC_TCTRL_TDLY_MASK, 0) |
+ FIELD_PREP(IMX8QXP_ADC_TCTRL_TPRI_MASK, IMX8QXP_ADC_TCTRL_TPRI_PRIORITY_HIGH) |
+ FIELD_PREP(IMX8QXP_ADC_TCTRL_HTEN_MASK, IMX8QXP_ADC_TCTRL_HTEN_HW_TIRG_DIS);
+ writel(adc_cfg, adc->regs + IMX8QXP_ADR_ADC_TCTRL(0));
+
+ /* config the cmd */
+ adc_cmdl = FIELD_PREP(IMX8QXP_ADC_CMDL_CSCALE_MASK, IMX8QXP_ADC_CMDL_CHANNEL_SCALE_FULL) |
+ FIELD_PREP(IMX8QXP_ADC_CMDL_MODE_MASK, IMX8QXP_ADC_CMDL_STANDARD_RESOLUTION) |
+ FIELD_PREP(IMX8QXP_ADC_CMDL_DIFF_MASK, IMX8QXP_ADC_CMDL_MODE_SINGLE) |
+ FIELD_PREP(IMX8QXP_ADC_CMDL_ABSEL_MASK, IMX8QXP_ADC_CMDL_SEL_A_A_B_CHANNEL) |
+ FIELD_PREP(IMX8QXP_ADC_CMDL_ADCH_MASK, channel);
+ writel(adc_cmdl, adc->regs + IMX8QXP_ADR_ADC_CMDL(0));
+
+ adc_cmdh = FIELD_PREP(IMX8QXP_ADC_CMDH_NEXT_MASK, 0) |
+ FIELD_PREP(IMX8QXP_ADC_CMDH_LOOP_MASK, 0) |
+ FIELD_PREP(IMX8QXP_ADC_CMDH_AVGS_MASK, 7) |
+ FIELD_PREP(IMX8QXP_ADC_CMDH_STS_MASK, 0) |
+ FIELD_PREP(IMX8QXP_ADC_CMDH_LWI_MASK, IMX8QXP_ADC_CMDH_LWI_INCREMENT_DIS) |
+ FIELD_PREP(IMX8QXP_ADC_CMDH_CMPEN_MASK, IMX8QXP_ADC_CMDH_CMPEN_DIS);
+ writel(adc_cmdh, adc->regs + IMX8QXP_ADR_ADC_CMDH(0));
+}
+
+static void imx8qxp_adc_fifo_config(struct imx8qxp_adc *adc)
+{
+ u32 fifo_ctrl, interrupt_en;
+
+ fifo_ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL);
+ fifo_ctrl &= ~IMX8QXP_ADC_FCTRL_FWMARK_MASK;
+ /* set the watermark level to 1 */
+ fifo_ctrl |= FIELD_PREP(IMX8QXP_ADC_FCTRL_FWMARK_MASK, 0);
+ writel(fifo_ctrl, adc->regs + IMX8QXP_ADR_ADC_FCTRL);
+
+ /* FIFO Watermark Interrupt Enable */
+ interrupt_en = readl(adc->regs + IMX8QXP_ADR_ADC_IE);
+ interrupt_en |= FIELD_PREP(IMX8QXP_ADC_IE_FWMIE_MASK, 1);
+ writel(interrupt_en, adc->regs + IMX8QXP_ADR_ADC_IE);
+}
+
+static void imx8qxp_adc_disable(struct imx8qxp_adc *adc)
+{
+ u32 ctrl;
+
+ ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
+ ctrl &= ~FIELD_PREP(IMX8QXP_ADC_CTRL_ADC_EN_MASK, 1);
+ writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
+}
+
+static int imx8qxp_adc_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct imx8qxp_adc *adc = iio_priv(indio_dev);
+ struct device *dev = adc->dev;
+
+ u32 ctrl, vref_uv;
+ long ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ pm_runtime_get_sync(dev);
+
+ mutex_lock(&adc->lock);
+ reinit_completion(&adc->completion);
+
+ imx8qxp_adc_reg_config(adc, chan->channel);
+
+ imx8qxp_adc_fifo_config(adc);
+
+ /* adc enable */
+ ctrl = readl(adc->regs + IMX8QXP_ADR_ADC_CTRL);
+ ctrl |= FIELD_PREP(IMX8QXP_ADC_CTRL_ADC_EN_MASK, 1);
+ writel(ctrl, adc->regs + IMX8QXP_ADR_ADC_CTRL);
+ /* adc start */
+ writel(1, adc->regs + IMX8QXP_ADR_ADC_SWTRIG);
+
+ ret = wait_for_completion_interruptible_timeout(&adc->completion,
+ IMX8QXP_ADC_TIMEOUT);
+
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_sync_autosuspend(dev);
+
+ if (ret == 0) {
+ mutex_unlock(&adc->lock);
+ return -ETIMEDOUT;
+ }
+ if (ret < 0) {
+ mutex_unlock(&adc->lock);
+ return ret;
+ }
+
+ *val = FIELD_GET(IMX8QXP_ADC_RESFIFO_VAL_MASK,
+ readl(adc->regs + IMX8QXP_ADR_ADC_RESFIFO));
+
+ mutex_unlock(&adc->lock);
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ vref_uv = regulator_get_voltage(adc->vref);
+ *val = vref_uv / 1000;
+ *val2 = 12;
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = clk_get_rate(adc->clk) / 3;
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static irqreturn_t imx8qxp_adc_isr(int irq, void *dev_id)
+{
+ struct imx8qxp_adc *adc = dev_id;
+
+ u32 fifo_count;
+
+ fifo_count = FIELD_GET(IMX8QXP_ADC_FCTRL_FCOUNT_MASK,
+ readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL));
+
+ if (fifo_count)
+ complete(&adc->completion);
+
+ return IRQ_HANDLED;
+}
+
+static int imx8qxp_adc_reg_access(struct iio_dev *indio_dev, unsigned int reg,
+ unsigned int writeval, unsigned int *readval)
+{
+ struct imx8qxp_adc *adc = iio_priv(indio_dev);
+ struct device *dev = adc->dev;
+
+ if (!readval || reg % 4 || reg > IMX8QXP_ADR_ADC_TST)
+ return -EINVAL;
+
+ pm_runtime_get_sync(dev);
+
+ *readval = readl(adc->regs + reg);
+
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_sync_autosuspend(dev);
+
+ return 0;
+}
+
+static const struct iio_info imx8qxp_adc_iio_info = {
+ .read_raw = &imx8qxp_adc_read_raw,
+ .debugfs_reg_access = &imx8qxp_adc_reg_access,
+};
+
+static int imx8qxp_adc_probe(struct platform_device *pdev)
+{
+ struct imx8qxp_adc *adc;
+ struct iio_dev *indio_dev;
+ struct device *dev = &pdev->dev;
+ int irq;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
+ if (!indio_dev) {
+ dev_err(dev, "Failed allocating iio device\n");
+ return -ENOMEM;
+ }
+
+ adc = iio_priv(indio_dev);
+ adc->dev = dev;
+
+ mutex_init(&adc->lock);
+ adc->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(adc->regs))
+ return PTR_ERR(adc->regs);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ adc->clk = devm_clk_get(dev, "per");
+ if (IS_ERR(adc->clk))
+ return dev_err_probe(dev, PTR_ERR(adc->clk), "Failed getting clock\n");
+
+ adc->ipg_clk = devm_clk_get(dev, "ipg");
+ if (IS_ERR(adc->ipg_clk))
+ return dev_err_probe(dev, PTR_ERR(adc->ipg_clk), "Failed getting clock\n");
+
+ adc->vref = devm_regulator_get(dev, "vref");
+ if (IS_ERR(adc->vref))
+ return dev_err_probe(dev, PTR_ERR(adc->vref), "Failed getting reference voltage\n");
+
+ ret = regulator_enable(adc->vref);
+ if (ret) {
+ dev_err(dev, "Can't enable adc reference top voltage\n");
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, indio_dev);
+
+ init_completion(&adc->completion);
+
+ indio_dev->name = ADC_DRIVER_NAME;
+ indio_dev->info = &imx8qxp_adc_iio_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = imx8qxp_adc_iio_channels;
+ indio_dev->num_channels = ARRAY_SIZE(imx8qxp_adc_iio_channels);
+
+ ret = clk_prepare_enable(adc->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not prepare or enable the clock.\n");
+ goto error_regulator_disable;
+ }
+
+ ret = clk_prepare_enable(adc->ipg_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not prepare or enable the clock.\n");
+ goto error_adc_clk_disable;
+ }
+
+ ret = devm_request_irq(dev, irq, imx8qxp_adc_isr, 0, ADC_DRIVER_NAME, adc);
+ if (ret < 0) {
+ dev_err(dev, "Failed requesting irq, irq = %d\n", irq);
+ goto error_ipg_clk_disable;
+ }
+
+ imx8qxp_adc_reset(adc);
+
+ ret = iio_device_register(indio_dev);
+ if (ret) {
+ imx8qxp_adc_disable(adc);
+ dev_err(dev, "Couldn't register the device.\n");
+ goto error_ipg_clk_disable;
+ }
+
+ pm_runtime_set_active(dev);
+ pm_runtime_set_autosuspend_delay(dev, 50);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_enable(dev);
+
+ return 0;
+
+error_ipg_clk_disable:
+ clk_disable_unprepare(adc->ipg_clk);
+error_adc_clk_disable:
+ clk_disable_unprepare(adc->clk);
+error_regulator_disable:
+ regulator_disable(adc->vref);
+
+ return ret;
+}
+
+static int imx8qxp_adc_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+ struct imx8qxp_adc *adc = iio_priv(indio_dev);
+ struct device *dev = adc->dev;
+
+ pm_runtime_get_sync(dev);
+
+ iio_device_unregister(indio_dev);
+
+ imx8qxp_adc_disable(adc);
+
+ clk_disable_unprepare(adc->clk);
+ clk_disable_unprepare(adc->ipg_clk);
+ regulator_disable(adc->vref);
+
+ pm_runtime_disable(dev);
+ pm_runtime_put_noidle(dev);
+
+ return 0;
+}
+
+static int imx8qxp_adc_runtime_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct imx8qxp_adc *adc = iio_priv(indio_dev);
+
+ imx8qxp_adc_disable(adc);
+
+ clk_disable_unprepare(adc->clk);
+ clk_disable_unprepare(adc->ipg_clk);
+ regulator_disable(adc->vref);
+
+ return 0;
+}
+
+static int imx8qxp_adc_runtime_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct imx8qxp_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ ret = regulator_enable(adc->vref);
+ if (ret) {
+ dev_err(dev, "Can't enable adc reference top voltage, err = %d\n", ret);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(adc->clk);
+ if (ret) {
+ dev_err(dev, "Could not prepare or enable clock.\n");
+ goto err_disable_reg;
+ }
+
+ ret = clk_prepare_enable(adc->ipg_clk);
+ if (ret) {
+ dev_err(dev, "Could not prepare or enable clock.\n");
+ goto err_unprepare_clk;
+ }
+
+ imx8qxp_adc_reset(adc);
+
+ return 0;
+
+err_unprepare_clk:
+ clk_disable_unprepare(adc->clk);
+
+err_disable_reg:
+ regulator_disable(adc->vref);
+
+ return ret;
+}
+
+static const struct dev_pm_ops imx8qxp_adc_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
+ SET_RUNTIME_PM_OPS(imx8qxp_adc_runtime_suspend, imx8qxp_adc_runtime_resume, NULL)
+};
+
+static const struct of_device_id imx8qxp_adc_match[] = {
+ { .compatible = "nxp,imx8qxp-adc", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx8qxp_adc_match);
+
+static struct platform_driver imx8qxp_adc_driver = {
+ .probe = imx8qxp_adc_probe,
+ .remove = imx8qxp_adc_remove,
+ .driver = {
+ .name = ADC_DRIVER_NAME,
+ .of_match_table = imx8qxp_adc_match,
+ .pm = &imx8qxp_adc_pm_ops,
+ },
+};
+
+module_platform_driver(imx8qxp_adc_driver);
+
+MODULE_DESCRIPTION("i.MX8QuadXPlus ADC driver");
+MODULE_LICENSE("GPL v2");
--
2.25.1


2021-09-26 11:41:36

by Jonathan Cameron

[permalink] [raw]
Subject: Re: [PATCH v6 1/3] iio: imx8qxp-adc: Add driver support for NXP IMX8QXP ADC

On Sat, 25 Sep 2021 10:05:45 +0800
Cai Huoqing <[email protected]> wrote:

> The NXP i.MX 8QuadXPlus SOC has a new ADC IP, so add
> driver support for this ADC.
>
> Signed-off-by: Cai Huoqing <[email protected]>
Hi Cai Huoqing,

Having had a 'final' read through of the driver, I am basically happy
to merge this after Fabio has had time for another look (plus anyone else
who wishes to of course!)

There were a few minor things inline though that I'll tidy up whilst applying.
If you do a v7 for some other reason please sort these out as well.

Thanks,

Jonathan

...

> +#define IMX8QXP_ADR_ADC_TCTRL(tid) (0xc0 + tid * 4)
> +#define IMX8QXP_ADR_ADC_CMDH(cid) (0x100 + cid * 8)
> +#define IMX8QXP_ADR_ADC_CMDL(cid) (0x104 + cid * 8)

In macros, it is always a good idea to put brackets around
any use of parameters so as to avoid potential odd issues
due to operator precedence.

(0xc0 + (tid) * 4)

> +#define IMX8QXP_ADR_ADC_RESFIFO 0x300
> +#define IMX8QXP_ADR_ADC_TST 0xffc

...

> +
> +struct imx8qxp_adc {
> + struct device *dev;
> + void __iomem *regs;
> + struct clk *clk;
> + struct clk *ipg_clk;
> + struct regulator *vref;
> + struct mutex lock;

A lock should have documentation to identify what it's precise scope is.
I can add

/* Serialise ADC channel reads */
above the lock definition whilst applying if you aren't doing a v7 for
other reasons.

> + struct completion completion;
> +};
...


> +
> +static irqreturn_t imx8qxp_adc_isr(int irq, void *dev_id)
> +{
> + struct imx8qxp_adc *adc = dev_id;
> +

Really minor, but the blank line here doesn't help readability much and
is inconsistent with the rest of the driver. I might remove this whilst
applying if nothing else comes up.

> + u32 fifo_count;
> +
> + fifo_count = FIELD_GET(IMX8QXP_ADC_FCTRL_FCOUNT_MASK,
> + readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL));
> +
> + if (fifo_count)
> + complete(&adc->completion);
> +
> + return IRQ_HANDLED;
> +}
> +
...

2021-09-26 13:46:39

by Cai,Huoqing

[permalink] [raw]
Subject: Re: [PATCH v6 1/3] iio: imx8qxp-adc: Add driver support for NXP IMX8QXP ADC

On 26 9月 21 12:41:37, Jonathan Cameron wrote:
> On Sat, 25 Sep 2021 10:05:45 +0800
> Cai Huoqing <[email protected]> wrote:
>
> > The NXP i.MX 8QuadXPlus SOC has a new ADC IP, so add
> > driver support for this ADC.
> >
> > Signed-off-by: Cai Huoqing <[email protected]>
Hi Jonathan
Thanks for your feedback.
> Hi Cai Huoqing,
>
> Having had a 'final' read through of the driver, I am basically happy
> to merge this after Fabio has had time for another look (plus anyone else
> who wishes to of course!)
>
> There were a few minor things inline though that I'll tidy up whilst applying.
Feel free to fix these directly.
> If you do a v7 for some other reason please sort these out as well.
Sure, if v7 is needed for other issue, I will add these changes BTW.

Many thanks,
Cai

>
> Thanks,
>
> Jonathan
>
> ...
>
> > +#define IMX8QXP_ADR_ADC_TCTRL(tid) (0xc0 + tid * 4)
> > +#define IMX8QXP_ADR_ADC_CMDH(cid) (0x100 + cid * 8)
> > +#define IMX8QXP_ADR_ADC_CMDL(cid) (0x104 + cid * 8)
>
> In macros, it is always a good idea to put brackets around
> any use of parameters so as to avoid potential odd issues
> due to operator precedence.
>
> (0xc0 + (tid) * 4)
>
> > +#define IMX8QXP_ADR_ADC_RESFIFO 0x300
> > +#define IMX8QXP_ADR_ADC_TST 0xffc
>
> ...
>
> > +
> > +struct imx8qxp_adc {
> > + struct device *dev;
> > + void __iomem *regs;
> > + struct clk *clk;
> > + struct clk *ipg_clk;
> > + struct regulator *vref;
> > + struct mutex lock;
>
> A lock should have documentation to identify what it's precise scope is.
> I can add
>
> /* Serialise ADC channel reads */
> above the lock definition whilst applying if you aren't doing a v7 for
> other reasons.
>
> > + struct completion completion;
> > +};
> ...
>
>
> > +
> > +static irqreturn_t imx8qxp_adc_isr(int irq, void *dev_id)
> > +{
> > + struct imx8qxp_adc *adc = dev_id;
> > +
>
> Really minor, but the blank line here doesn't help readability much and
> is inconsistent with the rest of the driver. I might remove this whilst
> applying if nothing else comes up.
>
> > + u32 fifo_count;
> > +
> > + fifo_count = FIELD_GET(IMX8QXP_ADC_FCTRL_FCOUNT_MASK,
> > + readl(adc->regs + IMX8QXP_ADR_ADC_FCTRL));
> > +
> > + if (fifo_count)
> > + complete(&adc->completion);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> ...

2021-09-26 13:57:05

by Fabio Estevam

[permalink] [raw]
Subject: Re: [PATCH v6 1/3] iio: imx8qxp-adc: Add driver support for NXP IMX8QXP ADC

Hi Jonathan,

On Sun, Sep 26, 2021 at 8:37 AM Jonathan Cameron <[email protected]> wrote:
>
> On Sat, 25 Sep 2021 10:05:45 +0800
> Cai Huoqing <[email protected]> wrote:
>
> > The NXP i.MX 8QuadXPlus SOC has a new ADC IP, so add
> > driver support for this ADC.
> >
> > Signed-off-by: Cai Huoqing <[email protected]>
> Hi Cai Huoqing,
>
> Having had a 'final' read through of the driver, I am basically happy
> to merge this after Fabio has had time for another look (plus anyone else
> who wishes to of course!)

It looks good to me:

Reviewed-by: Fabio Estevam <[email protected]>

2021-09-26 14:10:34

by Jonathan Cameron

[permalink] [raw]
Subject: Re: [PATCH v6 1/3] iio: imx8qxp-adc: Add driver support for NXP IMX8QXP ADC

On Sat, 25 Sep 2021 10:05:45 +0800
Cai Huoqing <[email protected]> wrote:

> The NXP i.MX 8QuadXPlus SOC has a new ADC IP, so add
> driver support for this ADC.
>
> Signed-off-by: Cai Huoqing <[email protected]>

Hi. My local build tests throw up a "set but unused" warning which made me take
another look. I've fixed as commented below. Shout if that was not the right fix!



> +
> +static void imx8qxp_adc_reg_config(struct imx8qxp_adc *adc, int channel)
> +{
> + u32 adc_cfg, adc_tctrl, adc_cmdl, adc_cmdh;
> +
> + /* ADC configuration */
> + adc_cfg = FIELD_PREP(IMX8QXP_ADC_CFG_PWREN_MASK, 1) |
> + FIELD_PREP(IMX8QXP_ADC_CFG_PUDLY_MASK, 0x80)|
> + FIELD_PREP(IMX8QXP_ADC_CFG_REFSEL_MASK, 0) |
> + FIELD_PREP(IMX8QXP_ADC_CFG_PWRSEL_MASK, 3) |
> + FIELD_PREP(IMX8QXP_ADC_CFG_TPRICTRL_MASK, 0);
> + writel(adc_cfg, adc->regs + IMX8QXP_ADR_ADC_CFG);
> +
> + /* config the trigger control */
> + adc_tctrl = FIELD_PREP(IMX8QXP_ADC_TCTRL_TCMD_MASK, 1) |
> + FIELD_PREP(IMX8QXP_ADC_TCTRL_TDLY_MASK, 0) |
> + FIELD_PREP(IMX8QXP_ADC_TCTRL_TPRI_MASK, IMX8QXP_ADC_TCTRL_TPRI_PRIORITY_HIGH) |
> + FIELD_PREP(IMX8QXP_ADC_TCTRL_HTEN_MASK, IMX8QXP_ADC_TCTRL_HTEN_HW_TIRG_DIS);
> + writel(adc_cfg, adc->regs + IMX8QXP_ADR_ADC_TCTRL(0));
adc_tctrl I assume? I've changed it to that so shout if that was not what was intented.

> +
> + /* config the cmd */
> + adc_cmdl = FIELD_PREP(IMX8QXP_ADC_CMDL_CSCALE_MASK, IMX8QXP_ADC_CMDL_CHANNEL_SCALE_FULL) |
> + FIELD_PREP(IMX8QXP_ADC_CMDL_MODE_MASK, IMX8QXP_ADC_CMDL_STANDARD_RESOLUTION) |
> + FIELD_PREP(IMX8QXP_ADC_CMDL_DIFF_MASK, IMX8QXP_ADC_CMDL_MODE_SINGLE) |
> + FIELD_PREP(IMX8QXP_ADC_CMDL_ABSEL_MASK, IMX8QXP_ADC_CMDL_SEL_A_A_B_CHANNEL) |
> + FIELD_PREP(IMX8QXP_ADC_CMDL_ADCH_MASK, channel);
> + writel(adc_cmdl, adc->regs + IMX8QXP_ADR_ADC_CMDL(0));
> +
> + adc_cmdh = FIELD_PREP(IMX8QXP_ADC_CMDH_NEXT_MASK, 0) |
> + FIELD_PREP(IMX8QXP_ADC_CMDH_LOOP_MASK, 0) |
> + FIELD_PREP(IMX8QXP_ADC_CMDH_AVGS_MASK, 7) |
> + FIELD_PREP(IMX8QXP_ADC_CMDH_STS_MASK, 0) |
> + FIELD_PREP(IMX8QXP_ADC_CMDH_LWI_MASK, IMX8QXP_ADC_CMDH_LWI_INCREMENT_DIS) |
> + FIELD_PREP(IMX8QXP_ADC_CMDH_CMPEN_MASK, IMX8QXP_ADC_CMDH_CMPEN_DIS);
> + writel(adc_cmdh, adc->regs + IMX8QXP_ADR_ADC_CMDH(0));
> +}
> +