From: Billy Tsai <billy_tsai@aspeedtech.com>
To: <jic23@kernel.org>, <lars@metafoo.de>, <pmeerw@pmeerw.net>,
<robh+dt@kernel.org>, <joel@jms.id.au>, <andrew@aj.id.au>,
<p.zabel@pengutronix.de>, <billy_tsai@aspeedtech.com>,
<linux-iio@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-aspeed@lists.ozlabs.org>, <raltherr@google.com>
Cc: <BMC-SW@aspeedtech.com>
Subject: [v1 5/7] iio: adc: aspeed: Add func to set sampling rate.
Date: Mon, 19 Jul 2021 16:06:05 +0800 [thread overview]
Message-ID: <20210719080607.28712-6-billy_tsai@aspeedtech.com> (raw)
In-Reply-To: <20210719080607.28712-1-billy_tsai@aspeedtech.com>
Add the function to set the sampling rate and keep the sampling period
for a driver used to wait the lastest value.
Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
drivers/iio/adc/aspeed_adc.c | 35 ++++++++++++++++++++++++-----------
1 file changed, 24 insertions(+), 11 deletions(-)
diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index 6a77ac4e7dcb..b33ff9f0a3af 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -55,6 +55,7 @@
#define ASPEED_ADC_INIT_POLLING_TIME 500
#define ASPEED_ADC_INIT_TIMEOUT 500000
+#define ASPEED_ADC_DEF_SAMPLING_RATE 250000
enum aspeed_adc_version {
aspeed_adc_ast2400,
@@ -77,6 +78,7 @@ struct aspeed_adc_data {
struct clk_hw *clk_scaler;
struct reset_control *rst;
int vref;
+ u32 sample_period_ns;
};
#define ASPEED_CHAN(_idx, _data_reg_addr) { \
@@ -108,6 +110,26 @@ static const struct iio_chan_spec aspeed_adc_iio_channels[] = {
ASPEED_CHAN(15, 0x2E),
};
+static int aspeed_adc_set_sampling_rate(struct iio_dev *indio_dev, u32 rate)
+{
+ struct aspeed_adc_data *data = iio_priv(indio_dev);
+ const struct aspeed_adc_model_data *model_data =
+ of_device_get_match_data(data->dev);
+
+ if (rate < model_data->min_sampling_rate ||
+ rate > model_data->max_sampling_rate)
+ return -EINVAL;
+ /* Each sampling needs 12 clocks to covert.*/
+ clk_set_rate(data->clk_scaler->clk, rate * ASPEED_CLOCKS_PER_SAMPLE);
+
+ rate = clk_get_rate(data->clk_scaler->clk);
+ data->sample_period_ns = DIV_ROUND_UP_ULL(
+ (u64)NSEC_PER_SEC * ASPEED_CLOCKS_PER_SAMPLE, rate);
+ dev_dbg(data->dev, "Adc clock = %d sample period = %d ns", rate,
+ data->sample_period_ns);
+ return 0;
+}
+
static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
@@ -138,19 +160,9 @@ static int aspeed_adc_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
- struct aspeed_adc_data *data = iio_priv(indio_dev);
- const struct aspeed_adc_model_data *model_data =
- of_device_get_match_data(data->dev);
-
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
- if (val < model_data->min_sampling_rate ||
- val > model_data->max_sampling_rate)
- return -EINVAL;
-
- clk_set_rate(data->clk_scaler->clk,
- val * ASPEED_CLOCKS_PER_SAMPLE);
- return 0;
+ return aspeed_adc_set_sampling_rate(indio_dev, val);
case IIO_CHAN_INFO_SCALE:
case IIO_CHAN_INFO_RAW:
@@ -325,6 +337,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
ret = clk_prepare_enable(data->clk_scaler->clk);
if (ret)
goto clk_enable_error;
+ aspeed_adc_set_sampling_rate(indio_dev, ASPEED_ADC_DEF_SAMPLING_RATE);
adc_engine_control_reg_val =
readl(data->base + ASPEED_REG_ENGINE_CONTROL);
/* Start all channels in normal mode. */
--
2.25.1
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next prev parent reply other threads:[~2021-07-19 8:12 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-19 8:06 [v1 0/7] Add support for ast2600 ADC Billy Tsai
2021-07-19 8:06 ` [v1 1/7] dt-bindings: iio: adc: rename the aspeed adc yaml Billy Tsai
2021-07-19 8:06 ` [v1 2/7] dt-bindings: iio: adc: Binding ast2600 adc Billy Tsai
2021-07-19 8:06 ` [v1 3/7] iio: adc: aspeed: completes the bitfield declare Billy Tsai
2021-07-19 8:06 ` [v1 4/7] iio: adc: aspeed: Allow driver to support ast2600 Billy Tsai
2021-07-19 8:06 ` Billy Tsai [this message]
2021-07-19 8:06 ` [v1 6/7] iio: adc: aspeed: Add compensation phase Billy Tsai
2021-07-19 8:06 ` [v1 7/7] iio: adc: aspeed: Fix the calculate error of clock Billy Tsai
2021-07-24 16:24 ` [v1 0/7] Add support for ast2600 ADC Jonathan Cameron
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