Re: [PATCH v4 2/3] iio: adc: sophgo-saradc: Add driver for Sophgo CV18XX series SARADC

Chen Wang
2024-08-13T01:40:14Z

On 2024/8/12 23:00, Thomas Bonnefille wrote:
> This adds a driver for the common Sophgo SARADC.
Not common. Please double check the whole patchset.
>
> Signed-off-by: Thomas Bonnefille <thomas.bonnefille@bootlin.com>
> ---
> drivers/iio/adc/Kconfig | 10 ++
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/sophgo-cv18xx-adc.c | 208 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 219 insertions(+)
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index f60fe85a30d5..b10bf26d8e86 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -1156,6 +1156,16 @@ config SC27XX_ADC
> This driver can also be built as a module. If so, the module
> will be called sc27xx_adc.
>
> +config SOPHGO_CV18XX_ADC
> + tristate "Sophgo CV18XX series SARADC"
> + depends on ARCH_SOPHGO || COMPILE_TEST
> + help
> + Say yes here to build support for the SARADC integrated inside
> + the Sophgo CV18XX series SoCs.
> +
> + This driver can also be built as a module. If so, the module
> + will be called sophgo_cv18xx_adc.
> +
> config SPEAR_ADC
> tristate "ST SPEAr ADC"
> depends on PLAT_SPEAR || COMPILE_TEST
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index d370e066544e..24c241b12ef0 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -105,6 +105,7 @@ obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
> obj-$(CONFIG_RZG2L_ADC) += rzg2l_adc.o
> obj-$(CONFIG_SC27XX_ADC) += sc27xx_adc.o
> obj-$(CONFIG_SD_ADC_MODULATOR) += sd_adc_modulator.o
> +obj-$(CONFIG_SOPHGO_CV18XX_ADC) += sophgo-cv18xx-adc.o
> obj-$(CONFIG_SPEAR_ADC) += spear_adc.o
> obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
> obj-$(CONFIG_STM32_ADC) += stm32-adc.o
> diff --git a/drivers/iio/adc/sophgo-cv18xx-adc.c b/drivers/iio/adc/sophgo-cv18xx-adc.c
> new file mode 100644
> index 000000000000..ab7ee0f482cc
> --- /dev/null
> +++ b/drivers/iio/adc/sophgo-cv18xx-adc.c
> @@ -0,0 +1,208 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Sophgo CV18XX series SARADC Driver
> + *
> + * Copyright (C) Bootlin 2024
> + * Author: Thomas Bonnefille <thomas.bonnefille@bootlin.com>
> + */
> +
> +#include "linux/err.h"
<linux/err.h> ? And please sort with the file name alphabeta.
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/completion.h>
> +#include <linux/dev_printk.h>
> +#include <linux/interrupt.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iopoll.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/platform_device.h>
> +
> +#define CV18XX_ADC_CTRL_REG 0x04
> +#define CV18XX_ADC_EN BIT(0)

Should be one space between "#define" and macro-name. Please check this
for the whole file.

Run "./scripts/checkpatch.pl --strict" if it can help you check this
format error?

> +#define CV18XX_ADC_SEL(x) BIT((x) + 5)
> +#define CV18XX_ADC_STATUS_REG 0x08
> +#define CV18XX_ADC_BUSY BIT(0)
> +#define CV18XX_ADC_CYC_SET_REG 0x0C
> +/* The default cycle configuration is set to maximize the accuracy */
> +#define CV18XX_ADC_DEF_STARTUP_CYCLE_MASK 0x1F
> +#define CV18XX_ADC_DEF_SAMPLE_WINDOW_MASK 0xF00
> +#define CV18XX_ADC_DEF_CLOCK_DIVIDER_MASK 0xF000
> +#define CV18XX_ADC_DEF_COMPARE_CYCLE_MASK 0xF0000
> +#define CV18XX_ADC_CH_RESULT_REG(x) (0x14 + 4 * (x))
> +#define CV18XX_ADC_CH_RESULT GENMASK(11, 0)
> +#define CV18XX_ADC_CH_VALID BIT(15)
> +#define CV18XX_ADC_INTR_EN_REG 0x20
> +#define CV18XX_ADC_INTR_CLR_REG 0x24
> +#define CV18XX_ADC_INTR_CLR_BIT BIT(0)
> +#define CV18XX_ADC_INTR_STA_REG 0x28
> +#define CV18XX_ADC_INTR_STA_BIT BIT(0)
> +
> +#define CV18XX_ADC_CHANNEL(index) \
> + { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = index, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
> + .scan_index = index, \
> + }
> +
> +struct cv18xx_adc {
> + struct completion completion;
> + void __iomem *regs;
> + struct mutex lock; /* ADC Control and Result register */
> + int irq;
> +};
> +
> +static const struct iio_chan_spec sophgo_channels[] = {
> + CV18XX_ADC_CHANNEL(0),
> + CV18XX_ADC_CHANNEL(1),
> + CV18XX_ADC_CHANNEL(2),
> +};
> +
> +static void cv18xx_adc_start_measurement(struct cv18xx_adc *saradc,
> + int channel)
> +{
> + writel(0, saradc->regs + CV18XX_ADC_CTRL_REG);
> + writel(CV18XX_ADC_SEL(channel) | CV18XX_ADC_EN,
> + saradc->regs + CV18XX_ADC_CTRL_REG);
> +}
> +
> +static int cv18xx_adc_wait(struct cv18xx_adc *saradc)
> +{
> + if (saradc->irq < 0) {
> + u32 reg;
> +
> + return readl_poll_timeout(saradc->regs + CV18XX_ADC_STATUS_REG,
> + reg, !(reg & CV18XX_ADC_BUSY),
> + 500, 1000000);
> + }
> + return wait_for_completion_timeout(&saradc->completion,
> + msecs_to_jiffies(1000)) > 0
> + ? 0 : -ETIMEDOUT;
> +}
> +
> +static int cv18xx_adc_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:{
> + struct cv18xx_adc *saradc = iio_priv(indio_dev);
> + u32 sample;
> +
> + scoped_guard(mutex, &saradc->lock) {
> + int ret;
> +
> + cv18xx_adc_start_measurement(saradc, chan->scan_index);
> + ret = cv18xx_adc_wait(saradc);
> + if (ret < 0)
> + return ret;
> +
> + sample = readl(saradc->regs + CV18XX_ADC_CH_RESULT_REG(chan->scan_index));
> + }
> + if (!(sample & CV18XX_ADC_CH_VALID))
> + return -ENODATA;
> +
> + *val = sample & CV18XX_ADC_CH_RESULT;
> + return IIO_VAL_INT;
> + }
> + case IIO_CHAN_INFO_SCALE:
> + *val = 3300;
> + *val2 = 12;
> + return IIO_VAL_FRACTIONAL_LOG2;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static irqreturn_t cv18xx_adc_interrupt_handler(int irq, void *private)
> +{
> + struct cv18xx_adc *saradc = private;
> +
> + if (!(FIELD_GET(CV18XX_ADC_INTR_STA_BIT,
> + readl(saradc->regs + CV18XX_ADC_INTR_STA_REG))))
> + return IRQ_NONE;
> +
> + writel(CV18XX_ADC_INTR_CLR_BIT, saradc->regs + CV18XX_ADC_INTR_CLR_REG);
> + complete(&saradc->completion);
> + return IRQ_HANDLED;
> +}
> +
> +static const struct iio_info cv18xx_adc_info = {
> + .read_raw = &cv18xx_adc_read_raw,
> +};
> +
> +static int cv18xx_adc_probe(struct platform_device *pdev)
> +{
> + struct cv18xx_adc *saradc;
> + struct iio_dev *indio_dev;
> + struct clk *clk;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*saradc));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + saradc = iio_priv(indio_dev);
> + indio_dev->name = "sophgo-cv18xx-adc";
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->info = &cv18xx_adc_info;
> + indio_dev->num_channels = ARRAY_SIZE(sophgo_channels);
> + indio_dev->channels = sophgo_channels;
> +
> + clk = devm_clk_get_enabled(&pdev->dev, NULL);
> + if (IS_ERR(clk))
> + return PTR_ERR(clk);
> +
> + saradc->regs = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(saradc->regs))
> + return PTR_ERR(saradc->regs);
> +
> + saradc->irq = platform_get_irq_optional(pdev, 0);
> + if (saradc->irq >= 0) {
> + init_completion(&saradc->completion);
> + ret = devm_request_irq(&pdev->dev, saradc->irq,
> + cv18xx_adc_interrupt_handler, 0,
> + dev_name(&pdev->dev), saradc);
> + if (ret)
> + return ret;
> +
> + writel(1, saradc->regs + CV18XX_ADC_INTR_EN_REG);
> + }
> +
> + ret = devm_mutex_init(&pdev->dev, &saradc->lock);
> + if (ret)
> + return ret;
> +
> + platform_set_drvdata(pdev, indio_dev);
> + writel(FIELD_PREP(CV18XX_ADC_DEF_STARTUP_CYCLE_MASK, 0xF) |
> + FIELD_PREP(CV18XX_ADC_DEF_SAMPLE_WINDOW_MASK, 0xF) |
> + FIELD_PREP(CV18XX_ADC_DEF_CLOCK_DIVIDER_MASK, 0x1) |
> + FIELD_PREP(CV18XX_ADC_DEF_COMPARE_CYCLE_MASK, 0xF),
> + saradc->regs + CV18XX_ADC_CYC_SET_REG);
> +
> + return devm_iio_device_register(&pdev->dev, indio_dev);
> +}
> +
> +static const struct of_device_id cv18xx_adc_match[] = {
> + { .compatible = "sophgo,cv1800b-saradc", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, cv18xx_adc_match);
> +
> +static struct platform_driver cv18xx_adc_driver = {
> + .driver = {
> + .name = "sophgo-cv18xx-saradc",
> + .of_match_table = cv18xx_adc_match,
> + },
> + .probe = cv18xx_adc_probe,
> +};
> +module_platform_driver(cv18xx_adc_driver);
> +
> +MODULE_AUTHOR("Thomas Bonnefille <thomas.bonnefille@bootlin.com>");
> +MODULE_DESCRIPTION("Sophgo CV18XX series SARADC driver");
> +MODULE_LICENSE("GPL");