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authorFreeman Liu <freeman.liu@unisoc.com>2019-07-25 14:33:50 +0800
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2019-08-18 20:26:47 +0100
commit8de877d2bba5c3b83f6fce48965fbd89677be097 (patch)
treed7371833516627fb6d9678f1ded25bb41cd58b87 /drivers/iio
parent473d12f7638c93acbd9296a8cd455b203d5eb528 (diff)
downloadlinux-8de877d2bba5c3b83f6fce48965fbd89677be097.tar.bz2
iio: adc: sc27xx: Change to polling mode to read data
On Spreadtrum platform, the headphone will read one ADC channel multiple times to identify the headphone type, and the headphone identification is sensitive of the ADC reading time. And we found it will take longer time to reading ADC data by using interrupt mode comparing with the polling mode, thus we should change to polling mode to improve the efficiency of reading data, which can identify the headphone type successfully. Signed-off-by: Freeman Liu <freeman.liu@unisoc.com> Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
-rw-r--r--drivers/iio/adc/sc27xx_adc.c81
1 files changed, 27 insertions, 54 deletions
diff --git a/drivers/iio/adc/sc27xx_adc.c b/drivers/iio/adc/sc27xx_adc.c
index c2203a46f0d8..a6c046575ec3 100644
--- a/drivers/iio/adc/sc27xx_adc.c
+++ b/drivers/iio/adc/sc27xx_adc.c
@@ -3,7 +3,6 @@
#include <linux/hwspinlock.h>
#include <linux/iio/iio.h>
-#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/nvmem-consumer.h>
#include <linux/of.h>
@@ -46,14 +45,18 @@
/* Bits definitions for SC27XX_ADC_INT_CLR registers */
#define SC27XX_ADC_IRQ_CLR BIT(0)
+/* Bits definitions for SC27XX_ADC_INT_RAW registers */
+#define SC27XX_ADC_IRQ_RAW BIT(0)
+
/* Mask definition for SC27XX_ADC_DATA register */
#define SC27XX_ADC_DATA_MASK GENMASK(11, 0)
/* Timeout (ms) for the trylock of hardware spinlocks */
#define SC27XX_ADC_HWLOCK_TIMEOUT 5000
-/* Timeout (ms) for ADC data conversion according to ADC datasheet */
-#define SC27XX_ADC_RDY_TIMEOUT 100
+/* Timeout (us) for ADC data conversion according to ADC datasheet */
+#define SC27XX_ADC_RDY_TIMEOUT 1000000
+#define SC27XX_ADC_POLL_RAW_STATUS 500
/* Maximum ADC channel number */
#define SC27XX_ADC_CHANNEL_MAX 32
@@ -72,10 +75,8 @@ struct sc27xx_adc_data {
* subsystems which will access the unique ADC controller.
*/
struct hwspinlock *hwlock;
- struct completion completion;
int channel_scale[SC27XX_ADC_CHANNEL_MAX];
u32 base;
- int value;
int irq;
};
@@ -188,9 +189,7 @@ static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel,
int scale, int *val)
{
int ret;
- u32 tmp;
-
- reinit_completion(&data->completion);
+ u32 tmp, value, status;
ret = hwspin_lock_timeout_raw(data->hwlock, SC27XX_ADC_HWLOCK_TIMEOUT);
if (ret) {
@@ -203,6 +202,11 @@ static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel,
if (ret)
goto unlock_adc;
+ ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_CLR,
+ SC27XX_ADC_IRQ_CLR, SC27XX_ADC_IRQ_CLR);
+ if (ret)
+ goto disable_adc;
+
/* Configure the channel id and scale */
tmp = (scale << SC27XX_ADC_SCALE_SHIFT) & SC27XX_ADC_SCALE_MASK;
tmp |= channel & SC27XX_ADC_CHN_ID_MASK;
@@ -226,15 +230,22 @@ static int sc27xx_adc_read(struct sc27xx_adc_data *data, int channel,
if (ret)
goto disable_adc;
- ret = wait_for_completion_timeout(&data->completion,
- msecs_to_jiffies(SC27XX_ADC_RDY_TIMEOUT));
- if (!ret) {
- dev_err(data->dev, "read ADC data timeout\n");
- ret = -ETIMEDOUT;
- } else {
- ret = 0;
+ ret = regmap_read_poll_timeout(data->regmap,
+ data->base + SC27XX_ADC_INT_RAW,
+ status, (status & SC27XX_ADC_IRQ_RAW),
+ SC27XX_ADC_POLL_RAW_STATUS,
+ SC27XX_ADC_RDY_TIMEOUT);
+ if (ret) {
+ dev_err(data->dev, "read adc timeout, status = 0x%x\n", status);
+ goto disable_adc;
}
+ ret = regmap_read(data->regmap, data->base + SC27XX_ADC_DATA, &value);
+ if (ret)
+ goto disable_adc;
+
+ value &= SC27XX_ADC_DATA_MASK;
+
disable_adc:
regmap_update_bits(data->regmap, data->base + SC27XX_ADC_CTL,
SC27XX_ADC_EN, 0);
@@ -242,32 +253,11 @@ unlock_adc:
hwspin_unlock_raw(data->hwlock);
if (!ret)
- *val = data->value;
+ *val = value;
return ret;
}
-static irqreturn_t sc27xx_adc_isr(int irq, void *dev_id)
-{
- struct sc27xx_adc_data *data = dev_id;
- int ret;
-
- ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_CLR,
- SC27XX_ADC_IRQ_CLR, SC27XX_ADC_IRQ_CLR);
- if (ret)
- return IRQ_RETVAL(ret);
-
- ret = regmap_read(data->regmap, data->base + SC27XX_ADC_DATA,
- &data->value);
- if (ret)
- return IRQ_RETVAL(ret);
-
- data->value &= SC27XX_ADC_DATA_MASK;
- complete(&data->completion);
-
- return IRQ_HANDLED;
-}
-
static void sc27xx_adc_volt_ratio(struct sc27xx_adc_data *data,
int channel, int scale,
u32 *div_numerator, u32 *div_denominator)
@@ -454,11 +444,6 @@ static int sc27xx_adc_enable(struct sc27xx_adc_data *data)
if (ret)
goto disable_adc;
- ret = regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_EN,
- SC27XX_ADC_IRQ_EN, SC27XX_ADC_IRQ_EN);
- if (ret)
- goto disable_clk;
-
/* ADC channel scales' calibration from nvmem device */
ret = sc27xx_adc_scale_calibration(data, true);
if (ret)
@@ -484,9 +469,6 @@ static void sc27xx_adc_disable(void *_data)
{
struct sc27xx_adc_data *data = _data;
- regmap_update_bits(data->regmap, data->base + SC27XX_ADC_INT_EN,
- SC27XX_ADC_IRQ_EN, 0);
-
/* Disable ADC work clock and controller clock */
regmap_update_bits(data->regmap, SC27XX_ARM_CLK_EN,
SC27XX_CLK_ADC_EN | SC27XX_CLK_ADC_CLK_EN, 0);
@@ -551,7 +533,6 @@ static int sc27xx_adc_probe(struct platform_device *pdev)
return ret;
}
- init_completion(&sc27xx_data->completion);
sc27xx_data->dev = dev;
ret = sc27xx_adc_enable(sc27xx_data);
@@ -566,14 +547,6 @@ static int sc27xx_adc_probe(struct platform_device *pdev)
return ret;
}
- ret = devm_request_threaded_irq(dev, sc27xx_data->irq, NULL,
- sc27xx_adc_isr, IRQF_ONESHOT,
- pdev->name, sc27xx_data);
- if (ret) {
- dev_err(dev, "failed to request ADC irq\n");
- return ret;
- }
-
indio_dev->dev.parent = dev;
indio_dev->name = dev_name(dev);
indio_dev->modes = INDIO_DIRECT_MODE;