* [PATCH v3 1/2] iio: gts-helper: add helpers to ease searches of gain_sel and new_gain
2024-12-30 15:13 [PATCH v3 0/2] iio: light: fix scale in veml3235 and add helpers to iio-gts Javier Carrasco
@ 2024-12-30 15:13 ` Javier Carrasco
2024-12-30 15:13 ` [PATCH v3 2/2] iio: veml3235: fix scale to conform to ABI Javier Carrasco
1 sibling, 0 replies; 5+ messages in thread
From: Javier Carrasco @ 2024-12-30 15:13 UTC (permalink / raw)
To: Matti Vaittinen, Jonathan Cameron, Lars-Peter Clausen
Cc: linux-iio, linux-kernel, Jonathan Cameron, Javier Carrasco
This helper functions reduce the burden in the drivers that want to
fetch a gain and time selector for a given scale or a new optimal gain.
The former is currently achieved by calling
iio_gts_find_gain_sel_for_scale_using_time() for the current time
selector, and then iterating over the rest of time selectors if the
gain selector was not found.
The latter requires a combination of multiple iio-gts helpers to find
the new gain, look for an optimal gain if there was no exact match, and
set a minimum gain if the optimal gain is not in the range of available
gains.
Provide simpler workflows by means of functions that address common
patterns in the users of the iio-gts helpers.
Acked-by: Matti Vaittinen <mazziesaccount@gmail.com>
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
---
drivers/iio/industrialio-gts-helper.c | 77 +++++++++++++++++++++++++++++++++++
include/linux/iio/iio-gts-helper.h | 6 +++
2 files changed, 83 insertions(+)
diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c
index 3b5a998150623ba43c2f015c2c5d8a757743b893..d70ebe3bf7742906960c6af22102682c5b8dcdfa 100644
--- a/drivers/iio/industrialio-gts-helper.c
+++ b/drivers/iio/industrialio-gts-helper.c
@@ -915,6 +915,41 @@ int iio_gts_find_gain_sel_for_scale_using_time(struct iio_gts *gts, int time_sel
}
EXPORT_SYMBOL_NS_GPL(iio_gts_find_gain_sel_for_scale_using_time, "IIO_GTS_HELPER");
+/**
+ * iio_gts_find_gain_time_sel_for_scale - Fetch gain and time selectors for scale
+ * @gts: Gain time scale descriptor
+ * @scale_int: Integral part of the scale (typically val1)
+ * @scale_nano: Fractional part of the scale (nano or ppb)
+ * @gain_sel: Pointer to value where gain selector is stored.
+ * @time_sel: Pointer to value where time selector is stored.
+ *
+ * Wrapper around iio_gts_find_gain_for_scale_using_time() to fetch the
+ * gain and time selectors for a given scale.
+ *
+ * Return: 0 on success and -EINVAL on error.
+ */
+int iio_gts_find_gain_time_sel_for_scale(struct iio_gts *gts, int scale_int,
+ int scale_nano, int *gain_sel,
+ int *time_sel)
+{
+ int i, ret;
+
+ for (i = 0; i < gts->num_itime; i++) {
+ *time_sel = gts->itime_table[i].sel;
+ ret = iio_gts_find_gain_sel_for_scale_using_time(gts, *time_sel,
+ scale_int,
+ scale_nano,
+ gain_sel);
+ if (ret)
+ continue;
+
+ return 0;
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL_NS_GPL(iio_gts_find_gain_time_sel_for_scale, "IIO_GTS_HELPER");
+
static int iio_gts_get_total_gain(struct iio_gts *gts, int gain, int time)
{
const struct iio_itime_sel_mul *itime;
@@ -1086,6 +1121,48 @@ int iio_gts_find_new_gain_by_old_gain_time(struct iio_gts *gts, int old_gain,
}
EXPORT_SYMBOL_NS_GPL(iio_gts_find_new_gain_by_old_gain_time, "IIO_GTS_HELPER");
+/**
+ * iio_gts_find_new_gain_by_gain_time_min - compensate for time change
+ * @gts: Gain time scale descriptor
+ * @old_gain: Previously set gain
+ * @old_time: Selector corresponding previously set time
+ * @new_time: Selector corresponding new time to be set
+ * @new_gain: Pointer to value where new gain is to be written
+ * @in_range: Indicate if the @new_gain was in the range of
+ * supported gains.
+ *
+ * Wrapper around iio_gts_find_new_gain_by_old_gain_time() that tries to
+ * set an optimal value if no exact match was found, defaulting to the
+ * minimum gain to avoid saturations if the optimal value is not in the
+ * range of supported gains.
+ *
+ * Return: 0 on success and a negative value if no gain was found.
+ */
+int iio_gts_find_new_gain_by_gain_time_min(struct iio_gts *gts, int old_gain,
+ int old_time, int new_time,
+ int *new_gain, bool *in_range)
+{
+ int ret;
+
+ *in_range = true;
+ ret = iio_gts_find_new_gain_by_old_gain_time(gts, old_gain, old_time,
+ new_time, new_gain);
+ if (*new_gain < 0)
+ return -EINVAL;
+
+ if (ret) {
+ *new_gain = iio_find_closest_gain_low(gts, *new_gain, in_range);
+ if (*new_gain < 0) {
+ *new_gain = iio_gts_get_min_gain(gts);
+ if (*new_gain < 0)
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(iio_gts_find_new_gain_by_gain_time_min, "IIO_GTS_HELPER");
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Matti Vaittinen <mazziesaccount@gmail.com>");
MODULE_DESCRIPTION("IIO light sensor gain-time-scale helpers");
diff --git a/include/linux/iio/iio-gts-helper.h b/include/linux/iio/iio-gts-helper.h
index 9cb6c80dea716cb80b69bee5277230bafe1c9a95..e5de7a124bad6eb65414df364f84e81301b0690b 100644
--- a/include/linux/iio/iio-gts-helper.h
+++ b/include/linux/iio/iio-gts-helper.h
@@ -188,6 +188,9 @@ int iio_gts_total_gain_to_scale(struct iio_gts *gts, int total_gain,
int iio_gts_find_gain_sel_for_scale_using_time(struct iio_gts *gts, int time_sel,
int scale_int, int scale_nano,
int *gain_sel);
+int iio_gts_find_gain_time_sel_for_scale(struct iio_gts *gts, int scale_int,
+ int scale_nano, int *gain_sel,
+ int *time_sel);
int iio_gts_get_scale(struct iio_gts *gts, int gain, int time, int *scale_int,
int *scale_nano);
int iio_gts_find_new_gain_sel_by_old_gain_time(struct iio_gts *gts,
@@ -196,6 +199,9 @@ int iio_gts_find_new_gain_sel_by_old_gain_time(struct iio_gts *gts,
int iio_gts_find_new_gain_by_old_gain_time(struct iio_gts *gts, int old_gain,
int old_time, int new_time,
int *new_gain);
+int iio_gts_find_new_gain_by_gain_time_min(struct iio_gts *gts, int old_gain,
+ int old_time, int new_time,
+ int *new_gain, bool *in_range);
int iio_gts_avail_times(struct iio_gts *gts, const int **vals, int *type,
int *length);
int iio_gts_all_avail_scales(struct iio_gts *gts, const int **vals, int *type,
--
2.43.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v3 2/2] iio: veml3235: fix scale to conform to ABI
2024-12-30 15:13 [PATCH v3 0/2] iio: light: fix scale in veml3235 and add helpers to iio-gts Javier Carrasco
2024-12-30 15:13 ` [PATCH v3 1/2] iio: gts-helper: add helpers to ease searches of gain_sel and new_gain Javier Carrasco
@ 2024-12-30 15:13 ` Javier Carrasco
2024-12-31 8:39 ` Javier Carrasco
1 sibling, 1 reply; 5+ messages in thread
From: Javier Carrasco @ 2024-12-30 15:13 UTC (permalink / raw)
To: Matti Vaittinen, Jonathan Cameron, Lars-Peter Clausen
Cc: linux-iio, linux-kernel, Jonathan Cameron, Javier Carrasco
The current scale is not ABI-compliant as it is just the sensor gain
instead of the value that acts as a multiplier to be applied to the raw
value (there is no offset).
Use the iio-gts helpers to obtain the proper scale values according to
the gain and integration time to match the resolution tables from the
datasheet. When at it, use 'scale' instead of 'gain' consistently for
the get/set functions to avoid misunderstandings.
Fixes: c5a23f80c164 ("iio: light: add support for veml3235")
Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
---
drivers/iio/light/Kconfig | 1 +
drivers/iio/light/veml3235.c | 237 +++++++++++++++++++++++--------------------
2 files changed, 130 insertions(+), 108 deletions(-)
diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 4897258e3da5519f2757e5f105552596dc4473cf..e34e551eef3e8db006de56724ce3873c07b3360a 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -669,6 +669,7 @@ config VCNL4035
config VEML3235
tristate "VEML3235 ambient light sensor"
select REGMAP_I2C
+ select IIO_GTS_HELPER
depends on I2C
help
Say Y here if you want to build a driver for the Vishay VEML3235
diff --git a/drivers/iio/light/veml3235.c b/drivers/iio/light/veml3235.c
index f754980ea156a6e128ff159b816e09099197c5c7..77c9ae17ed4715a453075fcdd6a17c21e52bf137 100644
--- a/drivers/iio/light/veml3235.c
+++ b/drivers/iio/light/veml3235.c
@@ -11,6 +11,7 @@
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
+#include <linux/iio/iio-gts-helper.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
@@ -35,17 +36,33 @@ struct veml3235_data {
struct device *dev;
struct regmap *regmap;
struct veml3235_rf rf;
+ struct iio_gts gts;
};
-static const int veml3235_it_times[][2] = {
- { 0, 50000 },
- { 0, 100000 },
- { 0, 200000 },
- { 0, 400000 },
- { 0, 800000 },
+static const struct iio_itime_sel_mul veml3235_it_sel[] = {
+ GAIN_SCALE_ITIME_US(50000, 0, 1),
+ GAIN_SCALE_ITIME_US(100000, 1, 2),
+ GAIN_SCALE_ITIME_US(200000, 2, 4),
+ GAIN_SCALE_ITIME_US(400000, 3, 8),
+ GAIN_SCALE_ITIME_US(800000, 4, 16),
};
-static const int veml3235_scale_vals[] = { 1, 2, 4, 8 };
+/*
+ * The MSB (DG) doubles the value of the rest of the field, which leads to
+ * two possible combinations to obtain gain = 2 and gain = 4. The gain
+ * handling can be simplified by restricting DG = 1 to the only gain that
+ * really requires it, gain = 8. Note that "X10" is a reserved value.
+ */
+#define VEML3235_SEL_GAIN_X1 0
+#define VEML3235_SEL_GAIN_X2 1
+#define VEML3235_SEL_GAIN_X4 3
+#define VEML3235_SEL_GAIN_X8 7
+static const struct iio_gain_sel_pair veml3235_gain_sel[] = {
+ GAIN_SCALE_GAIN(1, VEML3235_SEL_GAIN_X1),
+ GAIN_SCALE_GAIN(2, VEML3235_SEL_GAIN_X2),
+ GAIN_SCALE_GAIN(4, VEML3235_SEL_GAIN_X4),
+ GAIN_SCALE_GAIN(8, VEML3235_SEL_GAIN_X8),
+};
static int veml3235_power_on(struct veml3235_data *data)
{
@@ -142,32 +159,17 @@ static const struct regmap_config veml3235_regmap_config = {
static int veml3235_get_it(struct veml3235_data *data, int *val, int *val2)
{
- int ret, reg;
+ int ret, it_idx;
- ret = regmap_field_read(data->rf.it, ®);
+ ret = regmap_field_read(data->rf.it, &it_idx);
if (ret)
return ret;
- switch (reg) {
- case 0:
- *val2 = 50000;
- break;
- case 1:
- *val2 = 100000;
- break;
- case 2:
- *val2 = 200000;
- break;
- case 3:
- *val2 = 400000;
- break;
- case 4:
- *val2 = 800000;
- break;
- default:
- return -EINVAL;
- }
+ ret = iio_gts_find_int_time_by_sel(&data->gts, it_idx);
+ if (ret < 0)
+ return ret;
+ *val2 = ret;
*val = 0;
return IIO_VAL_INT_PLUS_MICRO;
@@ -176,78 +178,78 @@ static int veml3235_get_it(struct veml3235_data *data, int *val, int *val2)
static int veml3235_set_it(struct iio_dev *indio_dev, int val, int val2)
{
struct veml3235_data *data = iio_priv(indio_dev);
- int ret, new_it;
+ int ret, gain_idx, it_idx, new_gain, prev_gain, prev_it;
+ bool in_range;
- if (val)
+ if (val || !iio_gts_valid_time(&data->gts, val2))
return -EINVAL;
- switch (val2) {
- case 50000:
- new_it = 0x00;
- break;
- case 100000:
- new_it = 0x01;
- break;
- case 200000:
- new_it = 0x02;
- break;
- case 400000:
- new_it = 0x03;
- break;
- case 800000:
- new_it = 0x04;
- break;
- default:
- return -EINVAL;
- }
+ ret = regmap_field_read(data->rf.it, &it_idx);
+ if (ret)
+ return ret;
- ret = regmap_field_write(data->rf.it, new_it);
- if (ret) {
- dev_err(data->dev,
- "failed to update integration time: %d\n", ret);
+ ret = regmap_field_read(data->rf.gain, &gain_idx);
+ if (ret)
return ret;
- }
- return 0;
+ prev_it = iio_gts_find_int_time_by_sel(&data->gts, it_idx);
+ if (prev_it < 0)
+ return prev_it;
+
+ if (prev_it == val2)
+ return 0;
+
+ prev_gain = iio_gts_find_gain_by_sel(&data->gts, gain_idx);
+ if (prev_gain < 0)
+ return prev_gain;
+
+ ret = iio_gts_find_new_gain_by_gain_time_min(&data->gts, prev_gain, prev_it,
+ val2, &new_gain, &in_range);
+ if (ret)
+ return ret;
+
+ if (!in_range)
+ dev_dbg(data->dev, "Optimal gain out of range\n");
+
+ ret = iio_gts_find_sel_by_int_time(&data->gts, val2);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_field_write(data->rf.it, ret);
+ if (ret)
+ return ret;
+
+ ret = iio_gts_find_sel_by_gain(&data->gts, new_gain);
+ if (ret < 0)
+ return ret;
+
+ return regmap_field_write(data->rf.gain, ret);
}
-static int veml3235_set_gain(struct iio_dev *indio_dev, int val, int val2)
+static int veml3235_set_scale(struct iio_dev *indio_dev, int val, int val2)
{
struct veml3235_data *data = iio_priv(indio_dev);
- int ret, new_gain;
+ int ret, it_idx, gain_sel, time_sel;
- if (val2 != 0)
- return -EINVAL;
+ ret = regmap_field_read(data->rf.it, &it_idx);
+ if (ret)
+ return ret;
- switch (val) {
- case 1:
- new_gain = 0x00;
- break;
- case 2:
- new_gain = 0x01;
- break;
- case 4:
- new_gain = 0x03;
- break;
- case 8:
- new_gain = 0x07;
- break;
- default:
- return -EINVAL;
- }
+ ret = iio_gts_find_gain_time_sel_for_scale(&data->gts, val, val2,
+ &gain_sel, &time_sel);
+ if (ret)
+ return ret;
- ret = regmap_field_write(data->rf.gain, new_gain);
- if (ret) {
- dev_err(data->dev, "failed to set gain: %d\n", ret);
+ ret = regmap_field_write(data->rf.it, time_sel);
+ if (ret)
return ret;
- }
- return 0;
+ return regmap_field_write(data->rf.gain, gain_sel);
}
-static int veml3235_get_gain(struct veml3235_data *data, int *val)
+static int veml3235_get_scale(struct veml3235_data *data, int *val, int *val2)
{
- int ret, reg;
+ int gain, it, reg, ret;
ret = regmap_field_read(data->rf.gain, ®);
if (ret) {
@@ -255,25 +257,25 @@ static int veml3235_get_gain(struct veml3235_data *data, int *val)
return ret;
}
- switch (reg & 0x03) {
- case 0:
- *val = 1;
- break;
- case 1:
- *val = 2;
- break;
- case 3:
- *val = 4;
- break;
- default:
- return -EINVAL;
+ gain = iio_gts_find_gain_by_sel(&data->gts, reg);
+ if (gain < 0)
+ return gain;
+
+ ret = regmap_field_read(data->rf.it, ®);
+ if (ret) {
+ dev_err(data->dev, "failed to read integration time %d\n", ret);
+ return ret;
}
- /* Double gain */
- if (reg & 0x04)
- *val *= 2;
+ it = iio_gts_find_int_time_by_sel(&data->gts, reg);
+ if (it < 0)
+ return it;
- return IIO_VAL_INT;
+ ret = iio_gts_get_scale(&data->gts, gain, it, val, val2);
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT_PLUS_NANO;
}
static int veml3235_read_raw(struct iio_dev *indio_dev,
@@ -307,7 +309,7 @@ static int veml3235_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_INT_TIME:
return veml3235_get_it(data, val, val2);
case IIO_CHAN_INFO_SCALE:
- return veml3235_get_gain(data, val);
+ return veml3235_get_scale(data, val, val2);
default:
return -EINVAL;
}
@@ -318,17 +320,27 @@ static int veml3235_read_avail(struct iio_dev *indio_dev,
const int **vals, int *type, int *length,
long mask)
{
+ struct veml3235_data *data = iio_priv(indio_dev);
+
switch (mask) {
case IIO_CHAN_INFO_INT_TIME:
- *vals = (int *)&veml3235_it_times;
- *length = 2 * ARRAY_SIZE(veml3235_it_times);
- *type = IIO_VAL_INT_PLUS_MICRO;
- return IIO_AVAIL_LIST;
+ return iio_gts_avail_times(&data->gts, vals, type, length);
case IIO_CHAN_INFO_SCALE:
- *vals = (int *)&veml3235_scale_vals;
- *length = ARRAY_SIZE(veml3235_scale_vals);
- *type = IIO_VAL_INT;
- return IIO_AVAIL_LIST;
+ return iio_gts_all_avail_scales(&data->gts, vals, type, length);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int veml3235_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_INT_TIME:
+ return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
@@ -342,7 +354,7 @@ static int veml3235_write_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_INT_TIME:
return veml3235_set_it(indio_dev, val, val2);
case IIO_CHAN_INFO_SCALE:
- return veml3235_set_gain(indio_dev, val, val2);
+ return veml3235_set_scale(indio_dev, val, val2);
}
return -EINVAL;
@@ -402,6 +414,13 @@ static int veml3235_hw_init(struct iio_dev *indio_dev)
struct device *dev = data->dev;
int ret;
+ ret = devm_iio_init_iio_gts(data->dev, 0, 272640000,
+ veml3235_gain_sel, ARRAY_SIZE(veml3235_gain_sel),
+ veml3235_it_sel, ARRAY_SIZE(veml3235_it_sel),
+ &data->gts);
+ if (ret)
+ return dev_err_probe(data->dev, ret, "failed to init iio gts\n");
+
/* Set gain to 1 and integration time to 100 ms */
ret = regmap_field_write(data->rf.gain, 0x00);
if (ret)
@@ -423,6 +442,7 @@ static const struct iio_info veml3235_info = {
.read_raw = veml3235_read_raw,
.read_avail = veml3235_read_avail,
.write_raw = veml3235_write_raw,
+ .write_raw_get_fmt = veml3235_write_raw_get_fmt,
};
static int veml3235_probe(struct i2c_client *client)
@@ -524,3 +544,4 @@ module_i2c_driver(veml3235_driver);
MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>");
MODULE_DESCRIPTION("VEML3235 Ambient Light Sensor");
MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("IIO_GTS_HELPER");
--
2.43.0
^ permalink raw reply related [flat|nested] 5+ messages in thread