Re: [PATCH v5 1/2] iio: light: Add support for UPISEMI uS5182d als and proximity sensor

From: Peter Meerwald
Date: Thu Aug 20 2015 - 05:21:21 EST


> Add support for UPISEMI us5182d als and proximity sensor.
> Supports raw readings.
> Data sheet for this device can be found here:
> http://www.upi-semi.com/temp/uS5182D-DS-P0103-temp.pdf

nitpicking below

> Signed-off-by: Adriana Reus <adriana.reus@xxxxxxxxx>
> ---
> Changes since v4:
> * Added a comment explaining the opmode set/store behaviour.
>
> drivers/iio/light/Kconfig | 10 +
> drivers/iio/light/Makefile | 1 +
> drivers/iio/light/us5182d.c | 507 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 518 insertions(+)
> create mode 100644 drivers/iio/light/us5182d.c
>
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index 7ed859a..0442f01 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -287,6 +287,16 @@ config TSL4531
> To compile this driver as a module, choose M here: the
> module will be called tsl4531.
>
> +config US5182D
> + tristate "UPISEMI light and proximity sensor"
> + depends on I2C
> + help
> + If you say yes here you get support for the UPISEMI US5182D
> + ambient light and proximity sensor.
> +
> + This driver can also be built as a module. If so, the module
> + will be called us5182d.
> +
> config VCNL4000
> tristate "VCNL4000 combined ALS and proximity sensor"
> depends on I2C
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index 91c74c0..528cc8f 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -27,4 +27,5 @@ obj-$(CONFIG_STK3310) += stk3310.o
> obj-$(CONFIG_TCS3414) += tcs3414.o
> obj-$(CONFIG_TCS3472) += tcs3472.o
> obj-$(CONFIG_TSL4531) += tsl4531.o
> +obj-$(CONFIG_US5182D) += us5182d.o
> obj-$(CONFIG_VCNL4000) += vcnl4000.o
> diff --git a/drivers/iio/light/us5182d.c b/drivers/iio/light/us5182d.c
> new file mode 100644
> index 0000000..7d356e6
> --- /dev/null
> +++ b/drivers/iio/light/us5182d.c
> @@ -0,0 +1,507 @@
> +/*
> + * Copyright (c) 2015 Intel Corporation
> + *
> + * Driver for UPISEMI us5182d Proximity and Ambient Light Sensor.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published by
> + * the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * To do: Interrupt support.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/acpi.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/mutex.h>
> +
> +#define US5182D_REG_CFG0 0x00
> +#define US5182D_CFG0_ONESHOT_EN BIT(6)
> +#define US5182D_CFG0_SHUTDOWN_EN BIT(7)
> +#define US5182D_CFG0_WORD_ENABLE BIT(0)
> +
> +#define US5182D_REG_CFG1 0x01
> +#define US5182D_CFG1_ALS_RES16 BIT(4)
> +#define US5182D_CFG1_AGAIN_DEFAULT 0x00
> +
> +#define US5182D_REG_CFG2 0x02
> +#define US5182D_CFG2_PX_RES16 BIT(4)
> +#define US5182D_CFG2_PXGAIN_DEFAULT BIT(2)
> +
> +#define US5182D_REG_CFG3 0x03
> +#define US5182D_CFG3_LED_CURRENT100 (BIT(4) | BIT(5))
> +
> +#define US5182D_REG_CFG4 0x10
> +
> +/*
> + * Registers for tuning the auto dark current cancelling feature.
> + * DARK_TH(reg 0x27,0x28) - threshold (counts) for auto dark cancelling.
> + * when ALS > DARK_TH --> ALS_Code = ALS - Upper(0x2A) * Dark
> + * when ALS < DARK_TH --> ALS_Code = ALS - Lower(0x29) * Dark
> + */
> +#define US5182D_REG_UDARK_TH 0x27
> +#define US5182D_REG_DARK_AUTO_EN 0x2b
> +#define US5182D_REG_AUTO_LDARK_GAIN 0x29
> +#define US5182D_REG_AUTO_HDARK_GAIN 0x2a
> +
> +#define US5182D_OPMODE_ALS 0x01
> +#define US5182D_OPMODE_PX 0x02
> +#define US5182D_OPMODE_SHIFT 4
> +
> +#define US5182D_REG_DARK_AUTO_EN_DEFAULT 0x80
> +#define US5182D_REG_AUTO_LDARK_GAIN_DEFAULT 0x16
> +#define US5182D_REG_AUTO_HDARK_GAIN_DEFAULT 0x00
> +
> +#define US5182D_REG_ADL 0x0c
> +#define US5182D_REG_PDL 0x0e
> +
> +#define US5182D_REG_MODE_STORE 0x21
> +#define US5182D_STORE_MODE 0x01
> +
> +#define US5182D_REG_CHIPID 0xb2
> +
> +#define US5182D_OPMODE_MASK GENMASK(5, 4)
> +#define US5182D_AGAIN_MASK 0x07
> +#define US5182D_RESET_CHIP 0x01
> +
> +#define US5182D_CHIPID 0x26
> +#define US5182D_DRV_NAME "us5182d"
> +
> +#define US5182D_GA_RESOLUTION 1000
> +
> +#define US5182D_READ_BYTE 1
> +#define US5182D_READ_WORD 2
> +#define US5182D_OPSTORE_SLEEP_TIME 20 /* ms */
> +
> +/* Available ranges: [12354, 7065, 3998, 2202, 1285, 498, 256, 138] lux */
> +static const int us5182d_scales[] = {188500, 107800, 61000, 33600, 19600, 7600,
> + 3900, 2100};
> +
> +/*
> + * Experimental tresholds that work with US5182D sensor on evaluation board

threshold

> + * roughly between 12-32 lux
> + */
> +static u16 us5182d_dark_ths_vals[] = {170, 200, 512, 512, 800, 2000, 4000,
> + 8000};
> +
> +enum mode {
> + US5182D_ALS_PX,
> + US5182D_ALS_ONLY,
> + US5182D_PX_ONLY
> +};
> +
> +struct us5182d_data {
> + struct i2c_client *client;
> + struct mutex lock;
> +
> + /* Glass attenuation factor */
> + u32 ga;
> +
> + /* Dark gain tuning */
> + u8 lower_dark_gain;
> + u8 upper_dark_gain;
> + u16 *us5182d_dark_ths;
> +
> + u8 opmode;
> +};
> +
> +static IIO_CONST_ATTR(in_illuminance_scale_available,
> + "0.0021 0.0039 0.0076 0.0196 0.0336 0.061 0.1078 0.1885");
> +
> +static struct attribute *us5182d_attrs[] = {
> + &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
> + NULL
> +};
> +
> +static const struct attribute_group us5182d_attr_group = {
> + .attrs = us5182d_attrs,
> +};
> +
> +static const struct {
> + u8 reg;
> + u8 val;
> +} us5182d_regvals[] = {
> + {US5182D_REG_CFG0, (US5182D_CFG0_SHUTDOWN_EN |
> + US5182D_CFG0_WORD_ENABLE)},
> + {US5182D_REG_CFG1, US5182D_CFG1_ALS_RES16},
> + {US5182D_REG_CFG2, (US5182D_CFG2_PX_RES16 |
> + US5182D_CFG2_PXGAIN_DEFAULT)},
> + {US5182D_REG_CFG3, US5182D_CFG3_LED_CURRENT100},
> + {US5182D_REG_MODE_STORE, US5182D_STORE_MODE},
> + {US5182D_REG_CFG4, 0x00},
> +};
> +
> +static const struct iio_chan_spec us5182d_channels[] = {
> + {
> + .type = IIO_LIGHT,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + },
> + {
> + .type = IIO_PROXIMITY,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + }
> +};
> +
> +static int us5182d_get_als(struct us5182d_data *data)
> +{
> + int ret;
> + unsigned long result;
> +
> + ret = i2c_smbus_read_word_data(data->client,
> + US5182D_REG_ADL);
> + if (ret < 0)
> + return ret;
> +
> + result = ret * data->ga / US5182D_GA_RESOLUTION;
> + if (result > 0xffff)
> + result = 0xffff;
> +
> + return result;
> +}
> +
> +static int us5182d_set_opmode(struct us5182d_data *data, u8 mode)
> +{
> + int ret;
> +
> + ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CFG0);
> + if (ret < 0)
> + return ret;
> +
> + /*
> + * In oneshot mode the chip will power itself down after taking the
> + * required measurement.
> + */
> + ret = ret | US5182D_CFG0_ONESHOT_EN;
> +
> + /* update mode */
> + ret = ret & ~US5182D_OPMODE_MASK;
> + ret = ret | (mode << US5182D_OPMODE_SHIFT);
> +
> + /*
> + * After updating the operating mode, the chip requires that
> + * the operation is stored, by writing 1 in the STORE_MODE
> + * register (auto-clearing).
> + */
> + ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG0, ret);
> + if (ret < 0)
> + return ret;
> +
> + if (mode == data->opmode)
> + return 0;
> +
> + ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_MODE_STORE,
> + US5182D_STORE_MODE);
> + if (ret < 0)
> + return ret;
> +
> + data->opmode = mode;
> + msleep(US5182D_OPSTORE_SLEEP_TIME);
> +
> + return 0;
> +}
> +
> +static int us5182d_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int *val,
> + int *val2, long mask)
> +{
> + struct us5182d_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + switch (chan->type) {
> + case IIO_LIGHT:
> + mutex_lock(&data->lock);
> + ret = us5182d_set_opmode(data, US5182D_OPMODE_ALS);
> + if (ret < 0)
> + goto out_err;
> +
> + ret = us5182d_get_als(data);
> + if (ret < 0)
> + goto out_err;
> + mutex_unlock(&data->lock);
> + *val = ret;
> + return IIO_VAL_INT;
> + case IIO_PROXIMITY:
> + mutex_lock(&data->lock);
> + ret = us5182d_set_opmode(data, US5182D_OPMODE_PX);
> + if (ret < 0)
> + goto out_err;
> +
> + ret = i2c_smbus_read_word_data(data->client,
> + US5182D_REG_PDL);
> + if (ret < 0)
> + goto out_err;
> + mutex_unlock(&data->lock);
> + *val = ret;
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> +
> + case IIO_CHAN_INFO_SCALE:
> + ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CFG1);
> + if (ret < 0)
> + return ret;
> +
> + *val = 0;
> + *val2 = us5182d_scales[ret & US5182D_AGAIN_MASK];
> +
> + return IIO_VAL_INT_PLUS_MICRO;
> + default:
> + return -EINVAL;
> + }
> +
> + return -EINVAL;
> +out_err:
> + mutex_unlock(&data->lock);
> + return ret;
> +}
> +
> +/**`

there is an extra character (`) to remove

> + * us5182d_update_dark_th - update Darh_Th registers
> + * @data us5182d_data structure
> + * @index index in us5182d_dark_ths array to use for the updated value
> + *
> + * Function needs to be called with a lock held because it needs two i2c write
> + * byte operations as these registers (0x27 0x28) don't work in word mode
> + * accessing.
> + */
> +static int us5182d_update_dark_th(struct us5182d_data *data, int index)
> +{
> + __be16 dark_th = cpu_to_be16(data->us5182d_dark_ths[index]);
> + int ret;
> +
> + ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_UDARK_TH,
> + ((u8 *)&dark_th)[0]);
> + if (ret < 0)
> + return ret;
> +
> + return i2c_smbus_write_byte_data(data->client, US5182D_REG_UDARK_TH + 1,
> + ((u8 *)&dark_th)[1]);
> +}
> +
> +/**`
> + * us5182d_apply_scale - update the ALS scale
> + * @data us5182d_data structure
> + * @index index in us5182d_scales array to use for the updated value
> + *
> + * Function needs to be called with a lock held as we're having more than one
> + * i2c operations.

operation

> + */
> +static int us5182d_apply_scale(struct us5182d_data *data, int index)
> +{
> + int ret;
> +
> + ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CFG1);
> + if (ret < 0)
> + return ret;
> +
> + ret = ret & (~US5182D_AGAIN_MASK);
> + ret |= index;
> +
> + ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG1, ret);
> + if (ret < 0)
> + return ret;
> +
> + return us5182d_update_dark_th(data, index);
> +}
> +
> +static int us5182d_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int val,
> + int val2, long mask)
> +{
> + struct us5182d_data *data = iio_priv(indio_dev);
> + int ret, i;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_SCALE:
> + if (val != 0)
> + return -EINVAL;
> + for (i = 0; i < ARRAY_SIZE(us5182d_scales); i++)
> + if (val2 == us5182d_scales[i]) {
> + mutex_lock(&data->lock);
> + ret = us5182d_apply_scale(data, i);
> + mutex_unlock(&data->lock);
> + return ret;
> + }
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static const struct iio_info us5182d_info = {
> + .driver_module = THIS_MODULE,
> + .read_raw = us5182d_read_raw,
> + .write_raw = us5182d_write_raw,
> + .attrs = &us5182d_attr_group,
> +};
> +
> +static int us5182d_reset(struct iio_dev *indio_dev)
> +{
> + struct us5182d_data *data = iio_priv(indio_dev);
> +
> + return i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG3,
> + US5182D_RESET_CHIP);
> +}
> +
> +static int us5182d_init(struct iio_dev *indio_dev)
> +{
> + struct us5182d_data *data = iio_priv(indio_dev);
> + int i, ret;
> +
> + ret = us5182d_reset(indio_dev);
> + if (ret < 0)
> + return ret;
> +
> + data->opmode = 0;
> + for (i = 0; i < ARRAY_SIZE(us5182d_regvals); i++) {
> + ret = i2c_smbus_write_byte_data(data->client,
> + us5182d_regvals[i].reg,
> + us5182d_regvals[i].val);
> + if (ret < 0)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void us5182d_get_platform_data(struct iio_dev *indio_dev)
> +{
> + struct us5182d_data *data = iio_priv(indio_dev);
> +
> + if (device_property_read_u32(&data->client->dev, "upisemi,glass-coef",
> + &data->ga))
> + data->ga = US5182D_GA_RESOLUTION;
> + if (device_property_read_u16_array(&data->client->dev,
> + "upisemi,dark-ths",
> + data->us5182d_dark_ths,
> + ARRAY_SIZE(us5182d_dark_ths_vals)))
> + data->us5182d_dark_ths = us5182d_dark_ths_vals;
> + if (device_property_read_u8(&data->client->dev,
> + "upisemi,upper-dark-gain",
> + &data->upper_dark_gain))
> + data->upper_dark_gain = US5182D_REG_AUTO_HDARK_GAIN_DEFAULT;
> + if (device_property_read_u8(&data->client->dev,
> + "upisemi,lower-dark-gain",
> + &data->lower_dark_gain))
> + data->lower_dark_gain = US5182D_REG_AUTO_LDARK_GAIN_DEFAULT;
> +}
> +
> +static int us5182d_dark_gain_config(struct iio_dev *indio_dev)
> +{
> + struct us5182d_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + ret = us5182d_update_dark_th(data, US5182D_CFG1_AGAIN_DEFAULT);
> + if (ret < 0)
> + return ret;
> +
> + ret = i2c_smbus_write_byte_data(data->client,
> + US5182D_REG_AUTO_LDARK_GAIN,
> + data->lower_dark_gain);
> + if (ret < 0)
> + return ret;
> +
> + ret = i2c_smbus_write_byte_data(data->client,
> + US5182D_REG_AUTO_HDARK_GAIN,
> + data->upper_dark_gain);
> + if (ret < 0)
> + return ret;
> +
> + return i2c_smbus_write_byte_data(data->client, US5182D_REG_DARK_AUTO_EN,
> + US5182D_REG_DARK_AUTO_EN_DEFAULT);
> +}
> +
> +static int us5182d_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct us5182d_data *data;
> + struct iio_dev *indio_dev;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + data = iio_priv(indio_dev);
> + i2c_set_clientdata(client, indio_dev);
> + data->client = client;
> +
> + mutex_init(&data->lock);
> +
> + indio_dev->dev.parent = &client->dev;
> + indio_dev->info = &us5182d_info;
> + indio_dev->name = US5182D_DRV_NAME;
> + indio_dev->channels = us5182d_channels;
> + indio_dev->num_channels = ARRAY_SIZE(us5182d_channels);
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CHIPID);
> + if (ret != US5182D_CHIPID) {
> + dev_err(&data->client->dev,
> + "Failed to detect US5182 light chip\n");
> + return (ret < 0) ? ret : -ENODEV;
> + }
> +
> + us5182d_get_platform_data(indio_dev);
> + ret = us5182d_init(indio_dev);
> + if (ret < 0)
> + return ret;
> +
> + ret = us5182d_dark_gain_config(indio_dev);
> + if (ret < 0)
> + return ret;
> +
> + return iio_device_register(indio_dev);
> +}
> +
> +static int us5182d_remove(struct i2c_client *client)
> +{
> + iio_device_unregister(i2c_get_clientdata(client));
> + return i2c_smbus_write_byte_data(client, US5182D_REG_CFG0,
> + US5182D_CFG0_SHUTDOWN_EN);
> +}
> +
> +static const struct acpi_device_id us5182d_acpi_match[] = {
> + { "USD5182", 0},
> + {}
> +};
> +
> +MODULE_DEVICE_TABLE(acpi, us5182d_acpi_match);
> +
> +static const struct i2c_device_id us5182d_id[] = {
> + {"usd5182", 0},
> + {}
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, us5182d_id);
> +
> +static struct i2c_driver us5182d_driver = {
> + .driver = {
> + .name = US5182D_DRV_NAME,
> + .acpi_match_table = ACPI_PTR(us5182d_acpi_match),
> + },
> + .probe = us5182d_probe,
> + .remove = us5182d_remove,
> + .id_table = us5182d_id,
> +
> +};
> +module_i2c_driver(us5182d_driver);
> +
> +MODULE_AUTHOR("Adriana Reus <adriana.reus@xxxxxxxxx>");
> +MODULE_DESCRIPTION("Driver for us5182d Proximity and Light Sensor");
> +MODULE_LICENSE("GPL v2");
>

--

Peter Meerwald
+43-664-2444418 (mobile)
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