lkml.org 
[lkml]   [2022]   [Jun]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 06/10] iio: adc: mcp3911: add support for oversampling ratio
Date
The chip support oversampling ratio so expose it to userspace.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---
drivers/iio/adc/mcp3911.c | 72 +++++++++++++++++++++++++++++++++++++++
1 file changed, 72 insertions(+)

diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index e761feed5303..65831bef12f6 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -5,6 +5,8 @@
* Copyright (C) 2018 Marcus Folkesson <marcus.folkesson@gmail.com>
* Copyright (C) 2018 Kent Gustavsson <kent@minoris.se>
*/
+#include <linux/bitfield.h>
+#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
@@ -35,6 +37,7 @@
#define MCP3911_REG_CONFIG 0x0c
#define MCP3911_CONFIG_CLKEXT BIT(1)
#define MCP3911_CONFIG_VREFEXT BIT(2)
+#define MCP3911_CONFIG_OSR GENMASK(13, 11)

#define MCP3911_REG_OFFCAL_CH0 0x0e
#define MCP3911_REG_GAINCAL_CH0 0x11
@@ -53,6 +56,8 @@

#define MCP3911_NUM_CHANNELS 2

+static const int mcp3911_osr_table[] = {32, 64, 128, 256, 512, 1024, 2048, 4096};
+
struct mcp3911 {
struct spi_device *spi;
struct mutex lock;
@@ -108,6 +113,22 @@ static int mcp3911_update(struct mcp3911 *adc, u8 reg, u32 mask,
return mcp3911_write(adc, reg, val, len);
}

+
+static int mcp3911_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ *type = IIO_VAL_INT;
+ *vals = mcp3911_osr_table;
+ *length = ARRAY_SIZE(mcp3911_osr_table);
+ return IIO_AVAIL_LIST;
+ default:
+ return -EINVAL;
+ }
+}
static int mcp3911_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *channel, int *val,
int *val2, long mask)
@@ -134,6 +155,16 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,

ret = IIO_VAL_INT;
break;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ ret = mcp3911_read(adc,
+ MCP3911_REG_CONFIG, val, 2);
+ if (ret)
+ goto out;
+
+ *val = FIELD_GET(MCP3911_CONFIG_OSR, *val);
+ *val = 32 << *val;
+ ret = IIO_VAL_INT;
+ break;

case IIO_CHAN_INFO_SCALE:
if (adc->vref) {
@@ -186,6 +217,42 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
MCP3911_STATUSCOM_EN_OFFCAL,
MCP3911_STATUSCOM_EN_OFFCAL, 2);
break;
+
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ switch (val) {
+ case 4096:
+ val = FIELD_PREP(MCP3911_CONFIG_OSR, 0x07);
+ break;
+ case 2048:
+ val = FIELD_PREP(MCP3911_CONFIG_OSR, 0x06);
+ break;
+ case 1024:
+ val = FIELD_PREP(MCP3911_CONFIG_OSR, 0x05);
+ break;
+ case 512:
+ val = FIELD_PREP(MCP3911_CONFIG_OSR, 0x04);
+ break;
+ case 256:
+ val = FIELD_PREP(MCP3911_CONFIG_OSR, 0x03);
+ break;
+ case 128:
+ val = FIELD_PREP(MCP3911_CONFIG_OSR, 0x02);
+ break;
+ case 64:
+ val = FIELD_PREP(MCP3911_CONFIG_OSR, 0x01);
+ break;
+ case 32:
+ val = FIELD_PREP(MCP3911_CONFIG_OSR, 0x00);
+ break;
+ default:
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = mcp3911_update(adc, MCP3911_REG_CONFIG,
+ MCP3911_CONFIG_OSR,
+ val, 2);
+ break;
}

out:
@@ -198,9 +265,13 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
.indexed = 1, \
.channel = idx, \
.scan_index = idx, \
+ .scan_index = idx, \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_OFFSET) | \
BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_shared_by_type_available = \
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
.scan_type = { \
.sign = 's', \
.realbits = 24, \
@@ -252,6 +323,7 @@ static irqreturn_t mcp3911_trigger_handler(int irq, void *p)
static const struct iio_info mcp3911_info = {
.read_raw = mcp3911_read_raw,
.write_raw = mcp3911_write_raw,
+ .read_avail = mcp3911_read_avail,
};

static irqreturn_t mcp3911_interrupt(int irq, void *dev_id)
--
2.36.1
\
 
 \ /
  Last update: 2022-06-23 19:41    [W:0.170 / U:1.436 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site