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Message-ID: <9036a57e-be5e-49e1-6f0e-77b3a5e9fa12@rock-chips.com>
Date: Wed, 4 Mar 2020 09:39:10 +0800
From: xxm <xxm@...k-chips.com>
To: Jonathan Cameron <jic23@...nel.org>
Cc: Heiko Stuebner <heiko@...ech.de>, lars@...afoo.de,
linux-iio@...r.kernel.org,
Heiko Stuebner <heiko.stuebner@...obroma-systems.com>,
linux-kernel@...r.kernel.org, kever.yang@...k-chips.com,
linux-rockchip@...ts.infradead.org, pmeerw@...erw.net,
knaack.h@....de
Subject: Re: [PATCH] iio: adc: rockchip_saradc: Add support iio buffers【请注意,邮件由linux-rockchip-bounces+xxm=rock-chips.com@...ts.infradead.org代发】
Hi,
在 2020/3/4 4:32, Jonathan Cameron 写道:
> On Mon, 2 Mar 2020 10:11:02 +0800
> xxm <xxm@...k-chips.com> wrote:
>
>> Hi, Heiko
>>
>> 在 2020/3/1 19:23, Heiko Stuebner 写道:
>>> From: Simon Xue <xxm@...k-chips.com>
>>>
>>> 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@...k-chips.com>
>>> [some simplifications and added commit description]
>>> Signed-off-by: Heiko Stuebner <heiko.stuebner@...obroma-systems.com>
>>> ---
>>> 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.
>
Make use of iio_dev->scan_bytes to alloc a buffer in
iio_info->update_scan_mode callback for storing the
"data + timestamp" is another way
>> 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@...k-chips.com
>>
>>
>
>
>
>
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