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author | Marcus Folkesson <marcus.folkesson@gmail.com> | 2022-08-15 09:16:24 +0300 |
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committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2022-09-21 23:15:10 +0300 |
commit | 6d965885f4ea82f916d31f17f67b2ad771bdabac (patch) | |
tree | aa1b324559497747f4f488ede8f8484e43168cfe /drivers/iio | |
parent | 1a84fa695c7385b4f5547795149cb0bdd1073be8 (diff) | |
download | linux-6d965885f4ea82f916d31f17f67b2ad771bdabac.tar.xz |
iio: adc: mcp3911: add support for oversampling ratio
The chip supports oversampling ratio, so expose it to userspace.
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220815061625.35568-9-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
-rw-r--r-- | drivers/iio/adc/mcp3911.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c index 4e45cccef085..b35fd2c9c3c0 100644 --- a/drivers/iio/adc/mcp3911.c +++ b/drivers/iio/adc/mcp3911.c @@ -41,6 +41,7 @@ #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 @@ -59,6 +60,8 @@ #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; @@ -117,6 +120,36 @@ static int mcp3911_update(struct mcp3911 *adc, u8 reg, u32 mask, return mcp3911_write(adc, reg, val, len); } +static int mcp3911_write_raw_get_fmt(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_SCALE: + return IIO_VAL_INT_PLUS_NANO; + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + return IIO_VAL_INT; + default: + return IIO_VAL_INT_PLUS_NANO; + } +} + +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) @@ -145,6 +178,15 @@ 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) { @@ -204,6 +246,17 @@ 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: + for (int i = 0; i < sizeof(mcp3911_osr_table); i++) { + if (val == mcp3911_osr_table[i]) { + val = FIELD_PREP(MCP3911_CONFIG_OSR, i); + ret = mcp3911_update(adc, MCP3911_REG_CONFIG, MCP3911_CONFIG_OSR, + val, 2); + break; + } + } + break; } out: @@ -216,9 +269,12 @@ out: .indexed = 1, \ .channel = 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, \ @@ -278,6 +334,8 @@ out: static const struct iio_info mcp3911_info = { .read_raw = mcp3911_read_raw, .write_raw = mcp3911_write_raw, + .read_avail = mcp3911_read_avail, + .write_raw_get_fmt = mcp3911_write_raw_get_fmt, }; static int mcp3911_config(struct mcp3911 *adc) |