On Mon, 2 Mar 2020 10:11:02 +0800
xxm <xxm@xxxxxxxxxxxxxx> wrote:
> 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
Unfortunately this is a bit more complex than it seems.
The buffer needs to be big enough for all the channels
+ a 8 byte aligned space to put the timestamp in.
You can construct that in a fashion suitable to use in a
macro but it's a bit more fiddly than simply being the
maximum number of channels.
> 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
>
>
