Re: [PATCH] iio: light: Add support for ROHM RPR0521 sensor

From: Jonathan Cameron
Date: Sat May 23 2015 - 06:51:50 EST

On 22/05/15 13:36, Daniel Baluta wrote:
> This patch adds support for ROHM RPR0521 ambient light and proximity
> sensor. It offers raw readings for intensity and proximity.
>
> Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
A simple driver with some fiddly power management!
Mostly looks fine, but I'm not sure why there is an explicit enable in
the set_power_state function as well as the runtime ones.

Just to check, for the calibscale attributes... Does the device always report
at the same scale whatever the calibscale value?

E.g. Setting calibscale = 16 gives same answer from a raw read as calibscale = 2?

Just would be a bit unusual for a device to do this over such a range so I thought I'd
check.
> ---
> drivers/iio/light/Kconfig | 11 +
> drivers/iio/light/Makefile | 1 +
> drivers/iio/light/rpr0521.c | 579 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 591 insertions(+)
> create mode 100644 drivers/iio/light/rpr0521.c
>
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index e6198b7..cbc4677 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -168,6 +168,17 @@ config JSA1212
> To compile this driver as a module, choose M here:
> the module will be called jsa1212.
>
> +config RPR0521
> + tristate "ROHM RPR0521 ALS and proximity sensor driver"
> + depends on I2C
> + select REGMAP_I2C
> + help
> + Say Y here if you want to build support for ROHM's RPR0521
> + ambient light and proximity sensor device.
> +
> + To compile this driver as a module, choose M here:
> + the module will be called rpr0521.
> +
> config SENSORS_LM3533
> tristate "LM3533 ambient light sensor"
> depends on MFD_LM3533
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index e2d50fd..66fc2fd 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_HID_SENSOR_ALS) += hid-sensor-als.o
> obj-$(CONFIG_HID_SENSOR_PROX) += hid-sensor-prox.o
> obj-$(CONFIG_ISL29125) += isl29125.o
> obj-$(CONFIG_JSA1212) += jsa1212.o
> +obj-$(CONFIG_RPR0521) += rpr0521.o
> obj-$(CONFIG_SENSORS_LM3533) += lm3533-als.o
> obj-$(CONFIG_LTR501) += ltr501.o
> obj-$(CONFIG_SENSORS_TSL2563) += tsl2563.o
> diff --git a/drivers/iio/light/rpr0521.c b/drivers/iio/light/rpr0521.c
> new file mode 100644
> index 0000000..9d3d312
> --- /dev/null
> +++ b/drivers/iio/light/rpr0521.c
> @@ -0,0 +1,579 @@
> +/*
> + * RPR-0521 ROHM Ambient Light and Proximity Sensor
> + *
> + * Copyright (c) 2015, Intel Corporation.
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License. See the file COPYING in the main
> + * directory of this archive for more details.
> + *
> + * IIO driver for RPR-0521RS (7-bit I2C slave address 0x38).
> + *
> + * TODO: illuminance channel, PM support, buffer
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/delay.h>
> +#include <linux/acpi.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/pm_runtime.h>
> +
> +#define RPR0521_REG_SYSTEM_CTRL 0x40
> +#define RPR0521_REG_MODE_CTRL 0x41
> +#define RPR0521_REG_ALS_CTRL 0x42
> +#define RPR0521_REG_PXS_CTRL 0x43
> +#define RPR0521_REG_PXS_DATA 0x44 /* 16-bit, little endian */
> +#define RPR0521_REG_ALS_DATA0 0x46 /* 16-bit, little endian */
> +#define RPR0521_REG_ALS_DATA1 0x48 /* 16-bit, little endian */
> +#define RPR0521_REG_ID 0x92
> +
> +#define RPR0521_MODE_ALS_MASK BIT(7)
> +#define RPR0521_MODE_PXS_MASK BIT(6)
> +#define RPR0521_MODE_MEAS_TIME_MASK GENMASK(3, 0)
> +#define RPR0521_ALS_DATA0_GAIN_MASK (BIT(4) | BIT(5))
> +#define RPR0521_ALS_DATA0_GAIN_SHIFT 4
> +#define RPR0521_ALS_DATA1_GAIN_MASK (BIT(2) | BIT(3))
> +#define RPR0521_ALS_DATA1_GAIN_SHIFT 2
> +#define RPR0521_PXS_GAIN_MASK (BIT(4) | BIT(5))
> +#define RPR0521_PXS_GAIN_SHIFT 4
> +
> +#define RPR0521_MODE_ALS_ENABLE BIT(7)
> +#define RPR0521_MODE_ALS_DISABLE 0x00
> +#define RPR0521_MODE_PXS_ENABLE BIT(6)
> +#define RPR0521_MODE_PXS_DISABLE 0x00
> +
> +#define RPR0521_PXS_MAX_VAL (BIT(13) - 1)
> +#define RPR0521_MANUFACT_ID 0xE0
> +#define RPR0521_DEFAULT_MEAS_TIME 0x06 /* ALS - 100ms, PXS - 100ms */
> +
> +#define RPR0521_DRV_NAME "RPR0521"
> +#define RPR0521_REGMAP_NAME "rpr0521_regmap"
> +
> +#define RPR0521_SLEEP_DELAY_MS 2000
> +
static const
> +int rpr0521_als_gain[4] = {1, 2, 64, 128};
> +int rpr0521_pxs_gain[3] = {1, 2, 4};
> +
> +enum rpr0521_channel {
> + RPR0521_CHAN_ALS_DATA0,
> + RPR0521_CHAN_ALS_DATA1,
> + RPR0521_CHAN_PXS,
> +};
> +
static const
> +int rpr0521_data_reg[] = {
> + [RPR0521_CHAN_ALS_DATA0] = RPR0521_REG_ALS_DATA0,
> + [RPR0521_CHAN_ALS_DATA1] = RPR0521_REG_ALS_DATA1,
> + [RPR0521_CHAN_PXS] = RPR0521_REG_PXS_DATA,
> +};
> +
const
> +struct rpr0521_gain_info {
> + u8 reg;
> + u8 mask;
> + u8 shift;
> + int *gain;
> + int size;
> +} rpr0521_gain[] = {
> + [RPR0521_CHAN_ALS_DATA0] = {
> + .reg = RPR0521_REG_ALS_CTRL,
> + .mask = RPR0521_ALS_DATA0_GAIN_MASK,
> + .shift = RPR0521_ALS_DATA0_GAIN_SHIFT,
> + .gain = rpr0521_als_gain,
> + .size = ARRAY_SIZE(rpr0521_als_gain),
> + },
> + [RPR0521_CHAN_ALS_DATA1] = {
> + .reg = RPR0521_REG_ALS_CTRL,
> + .mask = RPR0521_ALS_DATA1_GAIN_MASK,
> + .shift = RPR0521_ALS_DATA1_GAIN_SHIFT,
> + .gain = rpr0521_als_gain,
> + .size = ARRAY_SIZE(rpr0521_als_gain),
> + },
> + [RPR0521_CHAN_PXS] = {
> + .reg = RPR0521_REG_PXS_CTRL,
> + .mask = RPR0521_PXS_GAIN_MASK,
> + .shift = RPR0521_PXS_GAIN_SHIFT,
> + .gain = rpr0521_pxs_gain,
> + .size = ARRAY_SIZE(rpr0521_pxs_gain),
> + },
> +};
> +
> +struct rpr0521_data {
> + struct i2c_client *client;
> +
> + /* protect device params updates (e.g state, gain) */
> + struct mutex lock;
> +
> + /* device active status */
> + bool als_dev_en;
> + bool pxs_dev_en;
> +
> + /* optimize runtime pm ops - enable device only if needed */
> + bool als_ps_need_en;
> + bool pxs_ps_need_en;
> +
> + struct regmap *regmap;
> +};
> +
> +static const struct iio_chan_spec rpr0521_channels[] = {
> + {
> + .type = IIO_INTENSITY,
> + .modified = 1,
> + .address = RPR0521_CHAN_ALS_DATA0,
> + .channel2 = IIO_MOD_LIGHT_BOTH,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_CALIBSCALE),
> + },
> + {
> + .type = IIO_INTENSITY,
> + .modified = 1,
> + .address = RPR0521_CHAN_ALS_DATA1,
> + .channel2 = IIO_MOD_LIGHT_IR,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_CALIBSCALE),
> + },
> + {
> + .type = IIO_PROXIMITY,
> + .address = RPR0521_CHAN_PXS,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_CALIBSCALE),
> + }
> +};
> +
> +static int rpr0521_als_enable(struct rpr0521_data *data, u8 status)
> +{
> + int ret;
> +
> + ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL,
> + RPR0521_MODE_ALS_MASK,
> + status);
> + if (ret < 0)
> + return ret;
> +
> + data->als_dev_en = true;
> +
> + return 0;
> +}
> +
> +static int rpr0521_pxs_enable(struct rpr0521_data *data, u8 status)
> +{
> + int ret;
> +
> + ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL,
> + RPR0521_MODE_PXS_MASK,
> + status);
> + if (ret < 0)
> + return ret;
> +
> + data->pxs_dev_en = true;
> +
> + return 0;
> +}
> +
> +static int rpr0521_set_power_state(struct rpr0521_data *data, bool on,
> + u8 device_mask)
> +{
> +#ifdef CONFIG_PM
> + int ret;
> + u8 update_mask = 0;
> +
> + if (device_mask & RPR0521_MODE_ALS_MASK) {
This is a rather fiddly bit of power management isn't it!

If we are enabling the channel and als_ps_need_en is not set (which means we
are not in runtime power saving?) and the channel is currently enabled then
set the update mask that turns the channel on then carry on.

If it's currently enabled, why would we want to set it at all?

> + if (on && !data->als_ps_need_en && data->pxs_dev_en)
> + update_mask |= RPR0521_MODE_ALS_MASK;
> + else
Otherwise we flag that we want the channel on when we do the get_sync below
which makes sense.

> + data->als_ps_need_en = on;
> + }
> +
> + if (device_mask & RPR0521_MODE_PXS_MASK) {
> + if (on && !data->pxs_ps_need_en && data->als_dev_en)
> + update_mask |= RPR0521_MODE_PXS_MASK;
> + else
> + data->pxs_ps_need_en = on;
> + }
> +
> + ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL,
> + update_mask, update_mask);
> + if (ret < 0)
> + return ret;
> +
> + if (on) {
> + ret = pm_runtime_get_sync(&data->client->dev);
> + } else {
> + pm_runtime_mark_last_busy(&data->client->dev);
> + ret = pm_runtime_put_autosuspend(&data->client->dev);
> + }
> + if (ret < 0) {
> + dev_err(&data->client->dev,
> + "Failed: rpr0521_set_power_state for %d, ret %d\n",
> + on, ret);
> + if (on)
> + pm_runtime_put_noidle(&data->client->dev);
> +
> + return ret;
> + }
> +#endif
> + return 0;
> +}
> +
> +int rpr0521_get_gain_index(int *gainv, int size, int gain)
> +{
> + int i;
> +
> + for (i = 0; i < size; i++)
> + if (gain == gainv[i])
> + return i;
blank line here.
> + return -EINVAL;
> +}
> +
> +int rpr0521_get_gain(struct rpr0521_data *data, int chan, int *val)
> +{
> + int ret, reg, idx;
> +
> + ret = regmap_read(data->regmap, rpr0521_gain[chan].reg, &reg);
> + if (ret < 0)
> + return ret;
> +
> + idx = (rpr0521_gain[chan].mask & reg) >> rpr0521_gain[chan].shift;
> + *val = rpr0521_gain[chan].gain[idx];
> +
> + return 0;
> +}
> +
> +int rpr0521_set_gain(struct rpr0521_data *data, int chan, int val)
> +{
> + int idx;
> +
> + idx = rpr0521_get_gain_index(rpr0521_gain[chan].gain,
> + rpr0521_gain[chan].size, val);
> + if (idx < 0)
> + return idx;
> +
> + return regmap_update_bits(data->regmap, rpr0521_gain[chan].reg,
> + rpr0521_gain[chan].mask,
> + idx << rpr0521_gain[chan].shift);
> +}
> +
> +static int rpr0521_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int *val,
> + int *val2, long mask)
> +{
> + struct rpr0521_data *data = iio_priv(indio_dev);
> + int ret;
> + u8 device_mask;
> + __le16 raw_data;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + switch (chan->type) {
> + case IIO_INTENSITY:
> + device_mask = RPR0521_MODE_ALS_MASK;
> + break;
> + case IIO_PROXIMITY:
> + device_mask = RPR0521_MODE_PXS_MASK;
> + break;
> + default:
> + return -EINVAL;
> + }
> + mutex_lock(&data->lock);
> + ret = rpr0521_set_power_state(data, true, device_mask);
> + if (ret < 0) {
> + mutex_unlock(&data->lock);
> + return ret;
> + }
> +
> + ret = regmap_bulk_read(data->regmap,
> + rpr0521_data_reg[chan->address],
> + &raw_data, 2);
> + if (ret < 0) {
> + rpr0521_set_power_state(data, false, device_mask);
> + mutex_unlock(&data->lock);
> + return ret;
> + }
> +
> + ret = rpr0521_set_power_state(data, false, device_mask);
> + mutex_unlock(&data->lock);
> + if (ret < 0)
> + return ret;
> +
> + *val = le16_to_cpu(raw_data);
> + /*
> + * proximity uses 12 bits, with bits 7:4 of PXS MSB DATA
> + * being always zero. Also, proximity MUST be exposed as
> + * a distance with lower values for closer objects.
> + */
> + if (chan->type == IIO_PROXIMITY)
> + *val = RPR0521_PXS_MAX_VAL - *val;
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_CALIBSCALE:
> + mutex_lock(&data->lock);
> + ret = rpr0521_get_gain(data, chan->address, val);
> + mutex_unlock(&data->lock);
> + if (ret < 0)
> + return ret;
> +
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int rpr0521_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int val,
> + int val2, long mask)
> +{
> + struct rpr0521_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_CALIBSCALE:
> + mutex_lock(&data->lock);
> + ret = rpr0521_set_gain(data, chan->address, val);
> + mutex_unlock(&data->lock);
> +
> + return ret;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static IIO_CONST_ATTR(in_intensity_calibscale_available, "1 2 64 128");
> +static IIO_CONST_ATTR(in_proximity_calibscale_available, "1 2 4");
> +
> +static struct attribute *rpr0521_attributes[] = {
> + &iio_const_attr_in_intensity_calibscale_available.dev_attr.attr,
> + &iio_const_attr_in_proximity_calibscale_available.dev_attr.attr,
> + NULL
> +};
> +
> +static const struct attribute_group rpr0521_attribute_group = {
> + .attrs = rpr0521_attributes,
> +};
> +
> +static const struct iio_info rpr0521_info = {
> + .driver_module = THIS_MODULE,
> + .read_raw = rpr0521_read_raw,
> + .write_raw = rpr0521_write_raw,
> + .attrs = &rpr0521_attribute_group,
> +};
> +
> +static int rpr0521_init(struct rpr0521_data *data)
> +{
> + int ret;
> + int id;
> +
> + ret = regmap_read(data->regmap, RPR0521_REG_ID, &id);
> + if (ret < 0) {
> + dev_err(&data->client->dev, "Failed to read REG_ID register\n");
> + return ret;
> + }
> +
> + if (id != RPR0521_MANUFACT_ID) {
> + dev_err(&data->client->dev, "Wrong id, got %x expected %x\n",
> + id, RPR0521_MANUFACT_ID);
> + return -ENODEV;
> + }
> +
> + /* set default measurement time - 100 ms for both ALS and PS */
> + ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL,
> + RPR0521_MODE_MEAS_TIME_MASK,
> + RPR0521_DEFAULT_MEAS_TIME);
> + if (ret) {
> + pr_err("regmap_update bits returned %d\n", ret);
> + return ret;
> + }
> +
> + ret = rpr0521_als_enable(data, RPR0521_MODE_ALS_ENABLE);
> + if (ret < 0)
> + return ret;
> + ret = rpr0521_pxs_enable(data, RPR0521_MODE_PXS_ENABLE);
> + if (ret < 0)
> + return ret;
> +
> + return 0;
> +}
> +
> +static int rpr0521_poweroff(struct rpr0521_data *data)
> +{
> + int ret;
> +
> + ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL,
> + RPR0521_MODE_ALS_MASK |
> + RPR0521_MODE_PXS_MASK,
> + 0x00);
> + if (ret < 0)
> + return ret;
> +
> + data->als_dev_en = false;
> + data->pxs_dev_en = false;
> +
> + return 0;
> +}
> +
> +static bool rpr0521_is_volatile_reg(struct device *dev, unsigned int reg)
> +{
> + switch (reg) {
> + case RPR0521_REG_MODE_CTRL:
> + case RPR0521_REG_ALS_CTRL:
> + case RPR0521_REG_PXS_CTRL:
> + return false;
> + default:
> + return true;
> + }
> +}
> +
> +static const struct regmap_config rpr0521_regmap_config = {
> + .name = RPR0521_REGMAP_NAME,
> +
> + .reg_bits = 8,
> + .val_bits = 8,
> +
> + .max_register = RPR0521_REG_ID,
> + .cache_type = REGCACHE_RBTREE,
> + .volatile_reg = rpr0521_is_volatile_reg,
> +};
> +
> +static int rpr0521_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct rpr0521_data *data;
> + struct iio_dev *indio_dev;
> + struct regmap *regmap;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + regmap = devm_regmap_init_i2c(client, &rpr0521_regmap_config);
> + if (IS_ERR(regmap)) {
> + dev_err(&client->dev, "Regmap init failed!\n");
> + return PTR_ERR(regmap);
> + }
> +
> + data = iio_priv(indio_dev);
> + i2c_set_clientdata(client, indio_dev);
> + data->client = client;
> + data->regmap = regmap;
> +
> + mutex_init(&data->lock);
> +
> + indio_dev->dev.parent = &client->dev;
> + indio_dev->info = &rpr0521_info;
> + indio_dev->name = RPR0521_DRV_NAME;
> + indio_dev->channels = rpr0521_channels;
> + indio_dev->num_channels = ARRAY_SIZE(rpr0521_channels);
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + ret = rpr0521_init(data);
> + if (ret < 0) {
> + dev_err(&client->dev, "rpr0521 chip init failed\n");
> + return ret;
> + }
> + ret = iio_device_register(indio_dev);
> + if (ret < 0)
> + return ret;
> +
> + ret = pm_runtime_set_active(&client->dev);
> + if (ret < 0)
> + goto err_iio_unregister;
> +
> + pm_runtime_enable(&client->dev);
> + pm_runtime_set_autosuspend_delay(&client->dev, RPR0521_SLEEP_DELAY_MS);
> + pm_runtime_use_autosuspend(&client->dev);
> +
> + return 0;
> +err_iio_unregister:
> + iio_device_unregister(indio_dev);
> + return ret;
> +}
> +
> +static int rpr0521_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> + pm_runtime_disable(&client->dev);
> + pm_runtime_set_suspended(&client->dev);
> + pm_runtime_put_noidle(&client->dev);
> +
> + iio_device_unregister(indio_dev);
> + rpr0521_poweroff(iio_priv(indio_dev));
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static int rpr0521_runtime_suspend(struct device *dev)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> + struct rpr0521_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + mutex_lock(&data->lock);
> + ret = rpr0521_poweroff(data);
//Disables the channels and sets *_dev_en = false.
> + mutex_unlock(&data->lock);
> +
> + return ret;
> +}
> +
> +static int rpr0521_runtime_resume(struct device *dev)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> + struct rpr0521_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + if (data->als_ps_need_en) {
> + ret = rpr0521_als_enable(data, RPR0521_MODE_ALS_ENABLE);
> + if (ret < 0)
> + return ret;
> + data->als_ps_need_en = false;
> + }
> +
> + if (data->pxs_ps_need_en) {
> + ret = rpr0521_pxs_enable(data, RPR0521_MODE_PXS_ENABLE);
> + if (ret < 0)
> + return ret;
> + data->pxs_ps_need_en = false;
> + }
> +
> + return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops rpr0521_pm_ops = {
> + SET_RUNTIME_PM_OPS(rpr0521_runtime_suspend,
> + rpr0521_runtime_resume, NULL)
> +};
> +
> +static const struct acpi_device_id rpr0521_acpi_match[] = {
> + {"RPR0521", 0},
> + { }
> +};
> +MODULE_DEVICE_TABLE(acpi, rpr0521_acpi_match);
> +
> +static const struct i2c_device_id rpr0521_id[] = {
> + {"rpr0521", 0},
> + { }
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, rpr0521_id);
> +
> +static struct i2c_driver rpr0521_driver = {
> + .driver = {
> + .name = RPR0521_DRV_NAME,
> + .pm = &rpr0521_pm_ops,
> + .acpi_match_table = ACPI_PTR(rpr0521_acpi_match),
> + },
> + .probe = rpr0521_probe,
> + .remove = rpr0521_remove,
> + .id_table = rpr0521_id,
> +};
> +
> +module_i2c_driver(rpr0521_driver);
> +
> +MODULE_AUTHOR("Daniel Baluta <daniel.baluta@xxxxxxxxx>");
> +MODULE_DESCRIPTION("RPR0521 ROHM Ambient Light and Proximity Sensor driver");
> +MODULE_LICENSE("GPL v2");
>

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