[PATCH v3 1/4] iio: adc: add IMX7D ADC driver support
Stefan Agner
stefan at agner.ch
Tue Nov 24 19:52:41 PST 2015
Hi Haibo,
Some comments below:
On 2015-11-20 07:48, Haibo Chen wrote:
> Freescale i.MX7D soc contains a new ADC IP. This patch add this ADC
> driver support, and the driver only support ADC software trigger.
>
> Signed-off-by: Haibo Chen <haibo.chen at freescale.com>
> ---
> drivers/iio/adc/Kconfig | 9 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/imx7d_adc.c | 570 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 580 insertions(+)
> create mode 100644 drivers/iio/adc/imx7d_adc.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 7868c74..bf0611c 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -194,6 +194,15 @@ config HI8435
> This driver can also be built as a module. If so, the module will be
> called hi8435.
>
> +config IMX7D_ADC
> + tristate "IMX7D ADC driver"
> + depends on OF
Hm, not sure, but shouldn't we use a proper depends here? Otherwise this
will show up as modules in all kinds of distributions.
> + help
> + Say yes here to build support for IMX7D ADC.
> +
> + This driver can also be built as a module. If so, the module will be
> + called imx7d_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 99b37a9..282ffc01 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
> obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
> obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
> obj-$(CONFIG_HI8435) += hi8435.o
> +obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
> obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
> obj-$(CONFIG_MAX1027) += max1027.o
> obj-$(CONFIG_MAX1363) += max1363.o
> diff --git a/drivers/iio/adc/imx7d_adc.c b/drivers/iio/adc/imx7d_adc.c
> new file mode 100644
> index 0000000..d9547bf
> --- /dev/null
> +++ b/drivers/iio/adc/imx7d_adc.c
> @@ -0,0 +1,570 @@
> +/*
> + * Freescale i.MX7D ADC driver
> + *
> + * Copyright (C) 2015 Freescale Semiconductor, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/clk.h>
> +#include <linux/completion.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/err.h>
Can you sort these alphabetically
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/driver.h>
> +
> +/* ADC register */
> +#define IMX7D_REG_ADC_CH_A_CFG1 0x00
> +#define IMX7D_REG_ADC_CH_A_CFG2 0x10
> +#define IMX7D_REG_ADC_CH_B_CFG1 0x20
> +#define IMX7D_REG_ADC_CH_B_CFG2 0x30
> +#define IMX7D_REG_ADC_CH_C_CFG1 0x40
> +#define IMX7D_REG_ADC_CH_C_CFG2 0x50
> +#define IMX7D_REG_ADC_CH_D_CFG1 0x60
> +#define IMX7D_REG_ADC_CH_D_CFG2 0x70
> +#define IMX7D_REG_ADC_CH_SW_CFG 0x80
> +#define IMX7D_REG_ADC_TIMER_UNIT 0x90
> +#define IMX7D_REG_ADC_DMA_FIFO 0xa0
> +#define IMX7D_REG_ADC_FIFO_STATUS 0xb0
> +#define IMX7D_REG_ADC_INT_SIG_EN 0xc0
> +#define IMX7D_REG_ADC_INT_EN 0xd0
> +#define IMX7D_REG_ADC_INT_STATUS 0xe0
> +#define IMX7D_REG_ADC_CHA_B_CNV_RSLT 0xf0
> +#define IMX7D_REG_ADC_CHC_D_CNV_RSLT 0x100
> +#define IMX7D_REG_ADC_CH_SW_CNV_RSLT 0x110
> +#define IMX7D_REG_ADC_DMA_FIFO_DAT 0x120
> +#define IMX7D_REG_ADC_ADC_CFG 0x130
> +
> +#define IMX7D_EACH_CHANNEL_REG_SHIF 0x20
I would call that OFFSET, SHIFT is typically used for a bit offset
within a register.
> +
> +#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN (0x1 << 31)
> +#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_DISABLE (0x0 << 31)
I would just define the _EN definition (along with using BIT).
Bitshifting a 0 is not really useful.
> +#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE BIT(30)
> +#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN BIT(29)
> +#define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL_SHIF 24
> +
> +#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4 (0x0 << 12)
> +#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8 (0x1 << 12)
> +#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16 (0x2 << 12)
> +#define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32 (0x3 << 12)
> +
> +#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4 (0x0 << 29)
> +#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8 (0x1 << 29)
> +#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16 (0x2 << 29)
> +#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32 (0x3 << 29)
> +#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64 (0x4 << 29)
> +#define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128 (0x5 << 29)
> +
> +#define IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN BIT(31)
> +#define IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN BIT(1)
> +#define IMX7D_REG_ADC_ADC_CFG_ADC_EN BIT(0)
> +
> +#define IMX7D_REG_ADC_INT_CHA_COV_INT_EN BIT(8)
> +#define IMX7D_REG_ADC_INT_CHB_COV_INT_EN BIT(9)
> +#define IMX7D_REG_ADC_INT_CHC_COV_INT_EN BIT(10)
> +#define IMX7D_REG_ADC_INT_CHD_COV_INT_EN BIT(11)
> +#define IMX7D_REG_ADC_INT_CHANNEL_INT_EN (IMX7D_REG_ADC_INT_CHA_COV_INT_EN | \
> + IMX7D_REG_ADC_INT_CHB_COV_INT_EN | \
> + IMX7D_REG_ADC_INT_CHC_COV_INT_EN | \
> + IMX7D_REG_ADC_INT_CHD_COV_INT_EN)
> +#define IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS 0xf00
> +
> +#define IMX7D_ADC_TIMEOUT msecs_to_jiffies(100)
> +
> +enum imx7d_adc_clk_pre_div {
> + IMX7D_ADC_ANALOG_CLK_PRE_DIV_4,
> + IMX7D_ADC_ANALOG_CLK_PRE_DIV_8,
> + IMX7D_ADC_ANALOG_CLK_PRE_DIV_16,
> + IMX7D_ADC_ANALOG_CLK_PRE_DIV_32,
> + IMX7D_ADC_ANALOG_CLK_PRE_DIV_64,
> + IMX7D_ADC_ANALOG_CLK_PRE_DIV_128,
> +};
> +
> +enum imx7d_adc_average_num {
> + IMX7D_ADC_AVERAGE_NUM_4,
> + IMX7D_ADC_AVERAGE_NUM_8,
> + IMX7D_ADC_AVERAGE_NUM_16,
> + IMX7D_ADC_AVERAGE_NUM_32,
> +};
> +
> +struct imx7d_adc_feature {
> + enum imx7d_adc_clk_pre_div clk_pre_div;
> + enum imx7d_adc_average_num avg_num;
> +
> + u32 core_time_unit; /* impact the sample rate */
> +
> + bool average_en;
> +};
> +
> +struct imx7d_adc {
> + struct device *dev;
> + void __iomem *regs;
> + struct clk *clk;
> +
> + u32 vref_uv;
> + u32 value;
> + u32 channel;
> + u32 pre_div_num;
> +
> + struct regulator *vref;
> + struct imx7d_adc_feature adc_feature;
> +
> + struct completion completion;
> +};
> +
> +struct imx7d_adc_analogue_core_clk {
> + u32 pre_div;
> + u32 reg_config;
> +};
> +
> +#define IMX7D_ADC_ALALOGUE_CLK_CONFIG(_pre_div, _reg_conf) { \
> + .pre_div = (_pre_div), \
> + .reg_config = (_reg_conf), \
> +}
> +
> +static const struct imx7d_adc_analogue_core_clk imx7d_adc_analogue_clk[] = {
> + IMX7D_ADC_ALALOGUE_CLK_CONFIG(4, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4),
> + IMX7D_ADC_ALALOGUE_CLK_CONFIG(8, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8),
> + IMX7D_ADC_ALALOGUE_CLK_CONFIG(16, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16),
> + IMX7D_ADC_ALALOGUE_CLK_CONFIG(32, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32),
> + IMX7D_ADC_ALALOGUE_CLK_CONFIG(64, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64),
> + IMX7D_ADC_ALALOGUE_CLK_CONFIG(128, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128),
> +};
> +
> +#define IMX7D_ADC_CHAN(_idx, _chan_type) { \
> + .type = (_chan_type), \
> + .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 imx7d_adc_iio_channels[] = {
> + IMX7D_ADC_CHAN(0, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(1, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(2, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(3, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(4, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(5, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(6, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(7, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(8, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(9, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(10, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(11, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(12, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(13, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(14, IIO_VOLTAGE),
> + IMX7D_ADC_CHAN(15, IIO_VOLTAGE),
> +};
> +
> +static const u32 imx7d_adc_average_num[] = {
> + IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4,
> + IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8,
> + IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16,
> + IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32,
> +};
> +
> +static void imx7d_adc_feature_config(struct imx7d_adc *info)
> +{
> + info->adc_feature.clk_pre_div = IMX7D_ADC_ANALOG_CLK_PRE_DIV_4;
> + info->adc_feature.avg_num = IMX7D_ADC_AVERAGE_NUM_32;
> + info->adc_feature.core_time_unit = 1;
> + info->adc_feature.average_en = true;
Since this function is about ADC features, I would pass in a pointer to
adc_feature. Gets rid of info-> on each line.
> +}
> +
> +static void imx7d_adc_sample_set(struct imx7d_adc *info)
> +{
> + struct imx7d_adc_feature *adc_feature = &info->adc_feature;
> + struct imx7d_adc_analogue_core_clk adc_analogure_clk;
> + u32 i;
> + u32 sample_rate = 0;
> +
> + /*
> + * Before sample set, disable channel A,B,C,D. Here we
> + * clear the bit 31 of register REG_ADC_CH_A\B\C\D_CFG1.
> + */
> + for (i = 0; i < 4; i++)
> + writel(IMX7D_REG_ADC_CH_CFG1_CHANNEL_DISABLE,
> + info->regs + i * IMX7D_EACH_CHANNEL_REG_SHIF);
This does not clear bit 31 only, but all bits. You need to read into
tmp, and clear the single bit using ~IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN...
What I would consider is using regmap. It would allow to use helpers
such as regmap_update_bits...
> +
> + adc_analogure_clk = imx7d_adc_analogue_clk[adc_feature->clk_pre_div];
> + sample_rate |= adc_analogure_clk.reg_config;
> + info->pre_div_num = adc_analogure_clk.pre_div;
> +
> + sample_rate |= adc_feature->core_time_unit;
> + writel(sample_rate, info->regs + IMX7D_REG_ADC_TIMER_UNIT);
> +}
> +
> +static void imx7d_adc_hw_init(struct imx7d_adc *info)
> +{
> + u32 cfg;
> + /* power up and enable adc analogue core */
> + cfg = readl(info->regs + IMX7D_REG_ADC_ADC_CFG);
> + cfg &= ~(IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN |
> IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN);
> + cfg |= IMX7D_REG_ADC_ADC_CFG_ADC_EN;
> + writel(cfg, info->regs + IMX7D_REG_ADC_ADC_CFG);
> +
> + /* enable channel A,B,C,D interrupt */
> + writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN, info->regs +
> IMX7D_REG_ADC_INT_SIG_EN);
> + writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN, info->regs + IMX7D_REG_ADC_INT_EN);
> +
> + imx7d_adc_sample_set(info);
> +}
> +
> +static void imx7d_adc_channel_set(struct imx7d_adc *info)
> +{
> + u32 cfg1 = 0;
> + u32 cfg2;
> + u32 channel;
> +
> + channel = info->channel;
> +
> + /* the channel choose single conversion, and enable average mode */
> + cfg1 |= (IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN |
> + IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE);
> + if (info->adc_feature.average_en)
> + cfg1 |= IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN;
> +
> + /*
> + * physical channel 0 chose logical channel A
> + * physical channel 1 chose logical channel B
> + * physical channel 2 chose logical channel C
> + * physical channel 3 chose logical channel D
> + */
> + cfg1 |= (channel << IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL_SHIF);
Matter of taste, but I would put the shifting logic into a define above
and use something like
IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(x)
> +
> + /* read register REG_ADC_CH_A\B\C\D_CFG2, according to the channel chosen */
> + cfg2 = readl(info->regs + IMX7D_EACH_CHANNEL_REG_SHIF * channel + 0x10);
> +
> + cfg2 |= imx7d_adc_average_num[info->adc_feature.avg_num];
> +
> + /* write the register REG_ADC_CH_A\B\C\D_CFG2, according to the
> channel chosen */
> + writel(cfg2, info->regs + IMX7D_EACH_CHANNEL_REG_SHIF * channel + 0x10);
> + writel(cfg1, info->regs + IMX7D_EACH_CHANNEL_REG_SHIF * channel);
> +}
> +
> +static u32 imx7d_adc_get_sample_rate(struct imx7d_adc *info)
> +{
> + /* input clock is always 24MHz */
> + u32 input_clk = 24000000;
> + u32 analogue_core_clk;
> + u32 core_time_unit = info->adc_feature.core_time_unit;
> + u32 sample_clk;
> + u32 tmp;
> +
> + analogue_core_clk = input_clk / info->pre_div_num;
> + tmp = (core_time_unit + 1) * 6;
> + sample_clk = analogue_core_clk / tmp;
> +
> + return sample_clk;
> +}
> +
> +static int imx7d_adc_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val,
> + int *val2,
> + long mask)
> +{
> + struct imx7d_adc *info = iio_priv(indio_dev);
> +
> + u32 channel;
> + long ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + mutex_lock(&indio_dev->mlock);
> + reinit_completion(&info->completion);
> +
> + channel = (chan->channel) & 0x03;
> + info->channel = channel;
> + imx7d_adc_channel_set(info);
> +
> + ret = wait_for_completion_interruptible_timeout
> + (&info->completion, IMX7D_ADC_TIMEOUT);
> + if (ret == 0) {
> + mutex_unlock(&indio_dev->mlock);
> + return -ETIMEDOUT;
> + }
> + if (ret < 0) {
> + mutex_unlock(&indio_dev->mlock);
> + return ret;
> + }
> +
> + *val = info->value;
> + mutex_unlock(&indio_dev->mlock);
> + return IIO_VAL_INT;
> +
> + case IIO_CHAN_INFO_SCALE:
> + info->vref_uv = regulator_get_voltage(info->vref);
> + *val = info->vref_uv / 1000;
> + *val2 = 12;
> + return IIO_VAL_FRACTIONAL_LOG2;
> +
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + *val = imx7d_adc_get_sample_rate(info);
> + *val2 = 0;
> + return IIO_VAL_INT;
> +
> + default:
> + break;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static int imx7d_adc_read_data(struct imx7d_adc *info)
> +{
> + u32 channel;
> + u32 value;
> +
> + channel = (info->channel) & 0x03;
> +
> + /*
> + * channel A and B conversion result share one register,
> + * bit[27~16] is the channel B conversion result,
> + * bit[11~0] is the channel A conversion result.
> + * channel C and D is the same.
> + */
> + if (channel < 2)
> + value = readl(info->regs + IMX7D_REG_ADC_CHA_B_CNV_RSLT);
> + else
> + value = readl(info->regs + IMX7D_REG_ADC_CHC_D_CNV_RSLT);
> + if (channel & 0x1) /* channel B or D */
> + value = (value >> 16) & 0xFFF;
> + else /* channel A or C */
> + value &= 0xFFF;
> +
> + return value;
> +}
> +
> +static irqreturn_t imx7d_adc_isr(int irq, void *dev_id)
> +{
> + struct imx7d_adc *info = (struct imx7d_adc *)dev_id;
> + int status;
> +
> + status = readl(info->regs + IMX7D_REG_ADC_INT_STATUS);
> + if (status & IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS) {
> + info->value = imx7d_adc_read_data(info);
> + complete(&info->completion);
> +
> + /*
> + * The register IMX7D_REG_ADC_INT_STATUS can't clear
> + * itself after read operation, need software to write
> + * 0 to the related bit. Here we clear the channel A/B/C/D
> + * conversion finished flag.
> + */
> + status &= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS;
> + writel(status, info->regs + IMX7D_REG_ADC_INT_STATUS);
> + return IRQ_HANDLED;
> + }
> +
> + /* For other bits of register IMX7D_REG_ADC_INT_STATUS, ignore them */
> + writel(0, info->regs + IMX7D_REG_ADC_INT_STATUS);
> + return IRQ_NONE;
> +}
> +
> +static int imx7d_adc_reg_access(struct iio_dev *indio_dev,
> + unsigned reg, unsigned writeval,
> + unsigned *readval)
> +{
> + struct imx7d_adc *info = iio_priv(indio_dev);
> +
> + if ((readval == NULL) ||
> + ((reg % 4) || (reg > IMX7D_REG_ADC_ADC_CFG)))
This looks somewhat hard to read. The parentheses around reg ar
unnecessary, also you can check for NULL using !.
if (!readval || reg % 4 || reg > IMX7D_REG_ADC_ADC_CFG)
...
> + return -EINVAL;
> +
> + *readval = readl(info->regs + reg);
> +
> + return 0;
> +}
> +
> +static const struct iio_info imx7d_adc_iio_info = {
> + .driver_module = THIS_MODULE,
> + .read_raw = &imx7d_adc_read_raw,
> + .debugfs_reg_access = &imx7d_adc_reg_access,
> +};
> +
> +static const struct of_device_id imx7d_adc_match[] = {
> + { .compatible = "fsl,imx7d-adc", },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, imx7d_adc_match);
> +
> +static int imx7d_adc_probe(struct platform_device *pdev)
> +{
> + struct imx7d_adc *info;
> + struct iio_dev *indio_dev;
> + struct resource *mem;
> + int irq;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(struct imx7d_adc));
> + if (!indio_dev) {
> + dev_err(&pdev->dev, "Failed allocating iio device\n");
> + return -ENOMEM;
> + }
> +
> + info = iio_priv(indio_dev);
> + info->dev = &pdev->dev;
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + info->regs = devm_ioremap_resource(&pdev->dev, mem);
> + if (IS_ERR(info->regs)) {
> + ret = PTR_ERR(info->regs);
> + dev_err(&pdev->dev, "failed to remap adc memory: %d\n", ret);
> + return ret;
> + }
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "no irq resource?\n");
> + return irq;
> + }
> +
> + info->clk = devm_clk_get(&pdev->dev, "adc");
> + if (IS_ERR(info->clk)) {
> + ret = PTR_ERR(info->clk);
> + dev_err(&pdev->dev, "failed getting clock, err = %d\n", ret);
> + return ret;
> + }
> +
> + info->vref = devm_regulator_get(&pdev->dev, "vref");
> + if (IS_ERR(info->vref)) {
> + ret = PTR_ERR(info->vref);
> + dev_err(&pdev->dev, "failed getting reference voltage: %d\n", ret);
> + return ret;
Use colon or "err =" a bit more consistence across these error messages.
--
Stefan
> + }
> +
> + ret = regulator_enable(info->vref);
> + if (ret)
> + return ret;
> +
> + platform_set_drvdata(pdev, indio_dev);
> +
> + init_completion(&info->completion);
> +
> + indio_dev->name = dev_name(&pdev->dev);
> + indio_dev->dev.parent = &pdev->dev;
> + indio_dev->dev.of_node = pdev->dev.of_node;
> + indio_dev->info = &imx7d_adc_iio_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->channels = imx7d_adc_iio_channels;
> + indio_dev->num_channels = ARRAY_SIZE(imx7d_adc_iio_channels);
> +
> + ret = clk_prepare_enable(info->clk);
> + if (ret) {
> + dev_err(&pdev->dev,
> + "Could not prepare or enable the clock.\n");
> + goto error_adc_clk_enable;
> + }
> +
> + ret = devm_request_irq(info->dev, irq,
> + imx7d_adc_isr, 0,
> + dev_name(&pdev->dev), info);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed requesting irq, irq = %d\n", irq);
> + goto error_iio_device_register;
> + }
> +
> + ret = iio_device_register(indio_dev);
> + if (ret) {
> + dev_err(&pdev->dev, "Couldn't register the device.\n");
> + goto error_iio_device_register;
> + }
> +
> + imx7d_adc_feature_config(info);
> + imx7d_adc_hw_init(info);
> +
> + return 0;
> +
> +error_iio_device_register:
> + clk_disable_unprepare(info->clk);
> +error_adc_clk_enable:
> + regulator_disable(info->vref);
> +
> + return ret;
> +}
> +
> +static int imx7d_adc_remove(struct platform_device *pdev)
> +{
> + struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> + struct imx7d_adc *info = iio_priv(indio_dev);
> +
> + iio_device_unregister(indio_dev);
> + regulator_disable(info->vref);
> + clk_disable_unprepare(info->clk);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused imx7d_adc_suspend(struct device *dev)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct imx7d_adc *info = iio_priv(indio_dev);
> + u32 adc_cfg;
> +
> + adc_cfg = readl(info->regs + IMX7D_REG_ADC_ADC_CFG);
> + adc_cfg |= IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN |
> + IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN;
> + adc_cfg &= ~IMX7D_REG_ADC_ADC_CFG_ADC_EN;
> + writel(adc_cfg, info->regs + IMX7D_REG_ADC_ADC_CFG);
> +
> + clk_disable_unprepare(info->clk);
> + regulator_disable(info->vref);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused imx7d_adc_resume(struct device *dev)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct imx7d_adc *info = iio_priv(indio_dev);
> + int ret;
> +
> + ret = regulator_enable(info->vref);
> + if (ret)
> + return ret;
> +
> + ret = clk_prepare_enable(info->clk);
> + if (ret) {
> + dev_err(info->dev,
> + "Could not prepare or enable clock.\n");
> + regulator_disable(info->vref);
> + return ret;
> + }
> +
> + imx7d_adc_hw_init(info);
> +
> + return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(imx7d_adc_pm_ops, imx7d_adc_suspend,
> imx7d_adc_resume);
> +
> +static struct platform_driver imx7d_adc_driver = {
> + .probe = imx7d_adc_probe,
> + .remove = imx7d_adc_remove,
> + .driver = {
> + .name = "imx7d_adc",
> + .of_match_table = imx7d_adc_match,
> + .pm = &imx7d_adc_pm_ops,
> + },
> +};
> +
> +module_platform_driver(imx7d_adc_driver);
> +
> +MODULE_AUTHOR("Haibo Chen <haibo.chen at freescale.com>");
> +MODULE_DESCRIPTION("Freeacale IMX7D ADC driver");
> +MODULE_LICENSE("GPL v2");
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