Re: [PATCH] iio: adc: rockchip_saradc: Add support iio buffers【请注意，邮件由linux-rockchip-bounces+xxm=rock-chips.com@xxxxxxxxxxxxxxxxxxx代发】

[xxm <xxm@xxxxxxxxxxxxxx>]

Hi, Heiko

在 2020/3/1 19:23, Heiko Stuebner 写道:
> From: Simon Xue <xxm@xxxxxxxxxxxxxx>
>
> Add the ability to also support access via (triggered) buffers
> next to the existing direct mode.
>
> Device in question is the Odroid Go Advance that connects a joystick
> to two of the saradc channels for X and Y axis and the new (and still
> pending) adc joystick driver of course wants to use triggered buffers
> from the iio subsystem.
>
> Signed-off-by: Simon Xue <xxm@xxxxxxxxxxxxxx>
> [some simplifications and added commit description]
> Signed-off-by: Heiko Stuebner <heiko.stuebner@xxxxxxxxxxxxxxxxxxxxx>
> ---
>   drivers/iio/adc/Kconfig           |   2 +
>   drivers/iio/adc/rockchip_saradc.c | 137 ++++++++++++++++++++++--------
>   2 files changed, 102 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 82e33082958c..55d2499ff757 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -787,6 +787,8 @@ config ROCKCHIP_SARADC
>   	tristate "Rockchip SARADC driver"
>   	depends on ARCH_ROCKCHIP || (ARM && COMPILE_TEST)
>   	depends on RESET_CONTROLLER
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
>   	help
>   	  Say yes here to build support for the SARADC found in SoCs from
>   	  Rockchip.
> diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
> index 582ba047c4a6..402b2210a682 100644
> --- a/drivers/iio/adc/rockchip_saradc.c
> +++ b/drivers/iio/adc/rockchip_saradc.c
> @@ -15,7 +15,11 @@
>   #include <linux/delay.h>
>   #include <linux/reset.h>
>   #include <linux/regulator/consumer.h>
> +#include <linux/iio/buffer.h>
>   #include <linux/iio/iio.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
>   
>   #define SARADC_DATA			0x00
>   
> @@ -34,7 +38,6 @@
>   #define SARADC_TIMEOUT			msecs_to_jiffies(100)
>   
>   struct rockchip_saradc_data {
> -	int				num_bits;
>   	const struct iio_chan_spec	*channels;
>   	int				num_channels;
>   	unsigned long			clk_rate;
> @@ -49,8 +52,37 @@ struct rockchip_saradc {
>   	struct reset_control	*reset;
>   	const struct rockchip_saradc_data *data;
>   	u16			last_val;
> +	const struct iio_chan_spec *last_chan;
>   };
>   
> +static void rockchip_saradc_power_down(struct rockchip_saradc *info)
> +{
> +	/* Clear irq & power down adc */
> +	writel_relaxed(0, info->regs + SARADC_CTRL);
> +}
> +
> +static int rockchip_saradc_conversion(struct rockchip_saradc *info,
> +				   struct iio_chan_spec const *chan)
> +{
> +	reinit_completion(&info->completion);
> +
> +	/* 8 clock periods as delay between power up and start cmd */
> +	writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC);
> +
> +	info->last_chan = chan;
> +
> +	/* Select the channel to be used and trigger conversion */
> +	writel(SARADC_CTRL_POWER_CTRL
> +			| (chan->channel & SARADC_CTRL_CHN_MASK)
> +			| SARADC_CTRL_IRQ_ENABLE,
> +		   info->regs + SARADC_CTRL);
> +
> +	if (!wait_for_completion_timeout(&info->completion, SARADC_TIMEOUT))
> +		return -ETIMEDOUT;
> +
> +	return 0;
> +}
> +
>   static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
>   				    struct iio_chan_spec const *chan,
>   				    int *val, int *val2, long mask)
> @@ -62,24 +94,12 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
>   	case IIO_CHAN_INFO_RAW:
>   		mutex_lock(&indio_dev->mlock);
>   
> -		reinit_completion(&info->completion);
> -
> -		/* 8 clock periods as delay between power up and start cmd */
> -		writel_relaxed(8, info->regs + SARADC_DLY_PU_SOC);
> -
> -		/* Select the channel to be used and trigger conversion */
> -		writel(SARADC_CTRL_POWER_CTRL
> -				| (chan->channel & SARADC_CTRL_CHN_MASK)
> -				| SARADC_CTRL_IRQ_ENABLE,
> -		       info->regs + SARADC_CTRL);
> -
> -		if (!wait_for_completion_timeout(&info->completion,
> -						 SARADC_TIMEOUT)) {
> -			writel_relaxed(0, info->regs + SARADC_CTRL);
> +		ret = rockchip_saradc_conversion(info, chan);
> +		if (ret) {
> +			rockchip_saradc_power_down(info);
>   			mutex_unlock(&indio_dev->mlock);
> -			return -ETIMEDOUT;
> +			return ret;
>   		}
> -
>   		*val = info->last_val;
>   		mutex_unlock(&indio_dev->mlock);
>   		return IIO_VAL_INT;
> @@ -91,7 +111,7 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
>   		}
>   
>   		*val = ret / 1000;
> -		*val2 = info->data->num_bits;
> +		*val2 = chan->scan_type.realbits;
>   		return IIO_VAL_FRACTIONAL_LOG2;
>   	default:
>   		return -EINVAL;
> @@ -104,10 +124,9 @@ static irqreturn_t rockchip_saradc_isr(int irq, void *dev_id)
>   
>   	/* Read value */
>   	info->last_val = readl_relaxed(info->regs + SARADC_DATA);
> -	info->last_val &= GENMASK(info->data->num_bits - 1, 0);
> +	info->last_val &= GENMASK(info->last_chan->scan_type.realbits - 1, 0);
>   
> -	/* Clear irq & power down adc */
> -	writel_relaxed(0, info->regs + SARADC_CTRL);
> +	rockchip_saradc_power_down(info);
>   
>   	complete(&info->completion);
>   
> @@ -118,51 +137,55 @@ static const struct iio_info rockchip_saradc_iio_info = {
>   	.read_raw = rockchip_saradc_read_raw,
>   };
>   
> -#define ADC_CHANNEL(_index, _id) {				\
> +#define ADC_CHANNEL(_index, _id, _res) {			\
>   	.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),	\
>   	.datasheet_name = _id,					\
> +	.scan_index = _index,					\
> +	.scan_type = {						\
> +		.sign = 'u',					\
> +		.realbits = _res,				\
> +		.storagebits = 16,				\
> +		.endianness = IIO_LE,				\
> +	},							\
>   }
>   
>   static const struct iio_chan_spec rockchip_saradc_iio_channels[] = {
> -	ADC_CHANNEL(0, "adc0"),
> -	ADC_CHANNEL(1, "adc1"),
> -	ADC_CHANNEL(2, "adc2"),
> +	ADC_CHANNEL(0, "adc0", 10),
> +	ADC_CHANNEL(1, "adc1", 10),
> +	ADC_CHANNEL(2, "adc2", 10),
>   };
>   
>   static const struct rockchip_saradc_data saradc_data = {
> -	.num_bits = 10,
>   	.channels = rockchip_saradc_iio_channels,
>   	.num_channels = ARRAY_SIZE(rockchip_saradc_iio_channels),
>   	.clk_rate = 1000000,
>   };
>   
>   static const struct iio_chan_spec rockchip_rk3066_tsadc_iio_channels[] = {
> -	ADC_CHANNEL(0, "adc0"),
> -	ADC_CHANNEL(1, "adc1"),
> +	ADC_CHANNEL(0, "adc0", 12),
> +	ADC_CHANNEL(1, "adc1", 12),
>   };
>   
>   static const struct rockchip_saradc_data rk3066_tsadc_data = {
> -	.num_bits = 12,
>   	.channels = rockchip_rk3066_tsadc_iio_channels,
>   	.num_channels = ARRAY_SIZE(rockchip_rk3066_tsadc_iio_channels),
>   	.clk_rate = 50000,
>   };
>   
>   static const struct iio_chan_spec rockchip_rk3399_saradc_iio_channels[] = {
> -	ADC_CHANNEL(0, "adc0"),
> -	ADC_CHANNEL(1, "adc1"),
> -	ADC_CHANNEL(2, "adc2"),
> -	ADC_CHANNEL(3, "adc3"),
> -	ADC_CHANNEL(4, "adc4"),
> -	ADC_CHANNEL(5, "adc5"),
> +	ADC_CHANNEL(0, "adc0", 10),
> +	ADC_CHANNEL(1, "adc1", 10),
> +	ADC_CHANNEL(2, "adc2", 10),
> +	ADC_CHANNEL(3, "adc3", 10),
> +	ADC_CHANNEL(4, "adc4", 10),
> +	ADC_CHANNEL(5, "adc5", 10),
>   };
>   
>   static const struct rockchip_saradc_data rk3399_saradc_data = {
> -	.num_bits = 10,
>   	.channels = rockchip_rk3399_saradc_iio_channels,
>   	.num_channels = ARRAY_SIZE(rockchip_rk3399_saradc_iio_channels),
>   	.clk_rate = 1000000,
> @@ -193,6 +216,39 @@ static void rockchip_saradc_reset_controller(struct reset_control *reset)
>   	reset_control_deassert(reset);
>   }
>   
> +static irqreturn_t rockchip_saradc_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *i_dev = pf->indio_dev;
> +	struct rockchip_saradc *info = iio_priv(i_dev);
> +	u16 data[20];
How about this:
#define MAX_CHANNEL_NUM 16
u16 data[MAX_CHANNEL_NUM];
> +	int ret;
> +	int i, j = 0;
> +
> +	mutex_lock(&i_dev->mlock);
> +
> +	for_each_set_bit(i, i_dev->active_scan_mask, i_dev->masklength) {
> +		const struct iio_chan_spec *chan = &i_dev->channels[i];
> +
> +		ret = rockchip_saradc_conversion(info, chan);
> +		if (ret) {
> +			rockchip_saradc_power_down(info);
> +			goto out;
> +		}
> +
> +		data[j] = info->last_val;
> +		j++;
> +	}
> +
> +	iio_push_to_buffers_with_timestamp(i_dev, data, iio_get_time_ns(i_dev));
> +out:
> +	mutex_unlock(&i_dev->mlock);
> +
> +	iio_trigger_notify_done(i_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
>   static int rockchip_saradc_probe(struct platform_device *pdev)
>   {
>   	struct rockchip_saradc *info = NULL;
> @@ -315,12 +371,19 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
>   	indio_dev->channels = info->data->channels;
>   	indio_dev->num_channels = info->data->num_channels;
>   
> -	ret = iio_device_register(indio_dev);
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +					 rockchip_saradc_trigger_handler, NULL);
devm_iio_triggered_buffer_setup seems better
>   	if (ret)
>   		goto err_clk;
>   
> +	ret = iio_device_register(indio_dev);
> +	if (ret)
> +		goto err_buffer_cleanup;
> +
>   	return 0;
>   
> +err_buffer_cleanup:
> +	iio_triggered_buffer_cleanup(indio_dev);
>   err_clk:
>   	clk_disable_unprepare(info->clk);
>   err_pclk:
xxm@xxxxxxxxxxxxxx