Re: [PATCH v2 1/1] iio: jsa1212: Add JSA1212 proximity/ALS sensor

[Jonathan Cameron <jic23@kernel.org>]

On 01/08/14 04:02, Kuppuswamy Sathyanarayanan wrote:
> This patch adds a new driver for solteam opto JSA1212 proximity and
> ambient light sensor.
>
> Basic details of the chip can be found here.
>
> http://www.solteamopto.com.tw/detail.php?ms=3&po_unit=2&pt_unit=29&p_unit=120
>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Very nice.  Some small comments inline.

The only element I really care about is the opaque use of a flags field
when a bitfield (or even booleans) would lead to clearer / simpler code.

Jonathan

> ---
>  drivers/iio/light/Kconfig   |   10 +
>  drivers/iio/light/Makefile  |    1 +
>  drivers/iio/light/jsa1212.c |  490 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 501 insertions(+)
>  create mode 100644 drivers/iio/light/jsa1212.c
>
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index c89740d..07d0a76 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -87,6 +87,16 @@ config HID_SENSOR_PROX
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called hid-sensor-prox.
>
> +config JSA1212
> +	tristate "JSA1212 ALS and proximity sensor driver"
> +	depends on I2C
> +	help
> +	 Say Y here if you want to build a IIO driver for JSA1212
> +	 proximity & ALS sensor device.
> +
> +	 To compile this driver as a module, choose M here:
> +	 the module will be called jsa1212.
> +
>  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 3eb36e5..ce85c86 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_CM36651)		+= cm36651.o
>  obj-$(CONFIG_GP2AP020A00F)	+= gp2ap020a00f.o
>  obj-$(CONFIG_HID_SENSOR_ALS)	+= hid-sensor-als.o
>  obj-$(CONFIG_HID_SENSOR_PROX)	+= hid-sensor-prox.o
> +obj-$(CONFIG_JSA1212)		+= jsa1212.o
>  obj-$(CONFIG_SENSORS_LM3533)	+= lm3533-als.o
>  obj-$(CONFIG_LTR501)		+= ltr501.o
>  obj-$(CONFIG_SENSORS_TSL2563)	+= tsl2563.o
> diff --git a/drivers/iio/light/jsa1212.c b/drivers/iio/light/jsa1212.c
> new file mode 100644
> index 0000000..1597183
> --- /dev/null
> +++ b/drivers/iio/light/jsa1212.c
> @@ -0,0 +1,490 @@
> +/*
> + * JSA1212 Ambient Light & Proximity Sensor Driver
> + *
> + * Copyright (c) 2014, Intel Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions 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.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/acpi.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/events.h>
> +
> +/* JSA1212 reg address */
> +#define JSA1212_CONF_REG		0x01
> +#define JSA1212_INT_REG			0x02
> +#define JSA1212_PXS_LT_REG		0x03
> +#define JSA1212_PXS_HT_REG		0x04
> +#define JSA1212_ALS_TH1_REG		0x05
> +#define JSA1212_ALS_TH2_REG		0x06
> +#define JSA1212_ALS_TH3_REG		0x07
> +#define JSA1212_PXS_DATA_REG		0x08
> +#define JSA1212_ALS_DT1_REG		0x09
> +#define JSA1212_ALS_DT2_REG		0x0A
> +#define JSA1212_ALS_RNG_REG		0x0B
> +#define JSA1212_MAX_REG			0x0C
> +
> +/* JSA1212 reg defaults */
> +#define JSA1212_CONF_REG_DEF		0x58
> +#define JSA1212_INT_REG_DEF		0x02
> +#define JSA1212_PXS_LT_REG_DEF		0x00
> +#define JSA1212_PXS_HT_REG_DEF		0xFF
> +#define JSA1212_ALS_TH1_REG_DEF		0x00
> +#define JSA1212_ALS_TH2_REG_DEF		0xF0
> +#define JSA1212_ALS_TH3_REG_DEF		0xFF
> +#define JSA1212_ALS_RNG_REG_DEF		0x00
> +
> +/* JSA1212 reg masks */
> +#define JSA1212_CONF_MASK		0xFF
> +#define JSA1212_INT_MASK		0xFF
> +#define JSA1212_PXS_LT_MASK		0xFF
> +#define JSA1212_PXS_HT_MASK		0xFF
> +#define JSA1212_ALS_TH1_MASK		0xFF
> +#define JSA1212_ALS_TH2_LT_MASK		0x0F
> +#define JSA1212_ALS_TH2_HT_MASK		0xF0
> +#define JSA1212_ALS_TH3_MASK		0xFF
> +#define JSA1212_PXS_DATA_MASK		0xFF
> +#define JSA1212_ALS_DATA_MASK		0xFFF
> +#define JSA1212_ALS_DT1_MASK		0xFF
> +#define JSA1212_ALS_DT2_MASK		0x0F
> +#define JSA1212_ALS_RNG_MASK		0x07
> +#define JSA1212_REG_MASK		0xFF
> +
> +/* JSA1212 CONF REG bits */
> +#define JSA1212_CONF_PXS_MASK		0x80
> +#define JSA1212_CONF_PXS_ENABLE		0x80
> +#define JSA1212_CONF_PXS_DISABLE	0x00
> +#define JSA1212_CONF_ALS_MASK		0x04
> +#define JSA1212_CONF_ALS_ENABLE		0x04
> +#define JSA1212_CONF_ALS_DISABLE	0x00
> +
> +/* JSA1212 INT REG bits */
> +#define JSA1212_INT_CTRL_MASK		0x01
> +#define JSA1212_INT_CTRL_EITHER		0x00
> +#define JSA1212_INT_CTRL_BOTH		0x01
> +#define JSA1212_INT_ALS_PRST_MASK	0x06
> +#define JSA1212_INT_ALS_PRST_1CONV	0x00
> +#define JSA1212_INT_ALS_PRST_4CONV	0x02
> +#define JSA1212_INT_ALS_PRST_8CONV	0x04
> +#define JSA1212_INT_ALS_PRST_16CONV	0x06
> +#define JSA1212_INT_ALS_FLAG_MASK	0x08
> +#define JSA1212_INT_ALS_FLAG_CLR	0x00
> +#define JSA1212_INT_PXS_PRST_MASK	0x60
> +#define JSA1212_INT_PXS_PRST_1CONV	0x00
> +#define JSA1212_INT_PXS_PRST_4CONV	0x20
> +#define JSA1212_INT_PXS_PRST_8CONV	0x40
> +#define JSA1212_INT_PXS_PRST_16CONV	0x60
> +#define JSA1212_INT_PXS_FLAG_MASK	0x80
> +#define JSA1212_INT_PXS_FLAG_CLR	0x00
> +
> +/* JSA1212 ALS RNG REG bits */
> +#define JSA1212_ALS_RNG_0_2048		0x00
> +#define JSA1212_ALS_RNG_0_1024		0x01
> +#define JSA1212_ALS_RNG_0_512		0x02
> +#define JSA1212_ALS_RNG_0_256		0x03
> +#define JSA1212_ALS_RNG_0_128		0x04
> +
> +/* JSA1212 INT threshold range */
> +#define JSA1212_ALS_TH_MIN	0x0000
> +#define JSA1212_ALS_TH_MAX	0x0FFF
> +#define JSA1212_PXS_TH_MIN	0x00
> +#define JSA1212_PXS_TH_MAX	0xFF
> +
> +#define JSA1212_ALS_DELAY_MS	0xC8
> +#define JSA1212_PXS_DELAY_MS	0x64
> +
> +enum jsa1212_op_mode {
> +	JSA1212_OPMODE_ALS_EN,
> +	JSA1212_OPMODE_PXS_EN,
> +};
> +
> +struct jsa1212_data {
> +	struct i2c_client *client;
> +	struct mutex lock;
> +	u8 als_rng_idx;

I'd be tempted to use a bit field in place of the opaque flags.
That way it is obvious what this can contain.

> +	unsigned long flags;
> +};
> +
> +/* ALS range idx to val mapping */
> +static const int jsa1212_als_range_val[] = {2048, 1024, 512, 256, 128,
> +						128, 128, 128};
> +
> +static int jsa1212_reg_update(struct jsa1212_data *data, u8 reg, u8 bit_mask,
> +					u8 new_val)
> +{
> +	u8 old_cmd, new_cmd;
> +	int ret;
> +
> +	ret = i2c_smbus_read_byte_data(data->client, reg);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev,
> +			"%s: read reg (0X%02X) cmd failed\n",
> +			__func__, reg);
> +		return ret;
> +	}
> +
> +	old_cmd = ret & JSA1212_REG_MASK;
> +	new_cmd = old_cmd & ~bit_mask;
> +	new_cmd |= new_val & bit_mask;
> +
> +	if (new_cmd != old_cmd) {
> +		ret = i2c_smbus_write_byte_data(data->client, reg, new_cmd);
> +		if (ret < 0) {
> +			dev_err(&data->client->dev,
> +				"%s: write reg (0X%02X) cmd (0X%02X) failed\n",
> +				__func__, reg, new_cmd);
> +			return ret;
> +		 }
> +	}
Perhaps it would be better to use regmap and avoid rerolling standard
functionality?
> +
> +	 return 0;
> +}
> +
> +/* Enables or disables ALS function based on status */
> +static int jsa1212_als_enable(struct jsa1212_data *data, u8 status)
> +{
> +	int ret;
> +
> +	ret = jsa1212_reg_update(data, JSA1212_CONF_REG,
> +				JSA1212_CONF_ALS_MASK,
> +				status);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (status)
> +		set_bit(JSA1212_OPMODE_ALS_EN, &data->flags);
> +	else
> +		clear_bit(JSA1212_OPMODE_ALS_EN, &data->flags);
> +
> +	return ret;
> +}
> +
> +/* Enables or disables PXS function based on status */
> +static int jsa1212_pxs_enable(struct jsa1212_data *data, u8 status)
> +{
> +	int ret;
> +
> +	ret = jsa1212_reg_update(data, JSA1212_CONF_REG,
> +				JSA1212_CONF_PXS_MASK,
> +				status);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (status)
> +		set_bit(JSA1212_OPMODE_PXS_EN, &data->flags);
> +	else
> +		clear_bit(JSA1212_OPMODE_PXS_EN, &data->flags);
> +
> +	return ret;
> +}
> +
> +static int jsa1212_read_als_data(struct jsa1212_data *data,
> +				unsigned int *val)
> +{
> +	int ret;
> +
> +	ret = jsa1212_als_enable(data, JSA1212_CONF_ALS_ENABLE);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Delay for data output */
> +	msleep(JSA1212_ALS_DELAY_MS);
> +
> +	/* Read 12 bit data */
> +	ret = i2c_smbus_read_word_data(data->client, JSA1212_ALS_DT1_REG);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "als data read err\n");
> +		return ret;
> +	}
> +
> +	*val = ret & JSA1212_ALS_DATA_MASK;
> +
> +	ret = jsa1212_als_enable(data, JSA1212_CONF_ALS_DISABLE);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int jsa1212_read_pxs_data(struct jsa1212_data *data,
> +				unsigned int *val)
> +{
> +	int ret;
> +
> +	ret = jsa1212_pxs_enable(data, JSA1212_CONF_PXS_ENABLE);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Delay for data output */
> +	msleep(JSA1212_PXS_DELAY_MS);
> +
> +	/* Read out all data */
> +	ret = i2c_smbus_read_byte_data(data->client, JSA1212_PXS_DATA_REG);
> +	if (ret < 0) {
> +		dev_err(&data->client->dev, "pxs data read err\n");
> +		return ret;
> +	}
> +
> +	*val = ret & JSA1212_PXS_DATA_MASK;
> +
> +	ret = jsa1212_pxs_enable(data, JSA1212_CONF_PXS_DISABLE);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int jsa1212_read_raw(struct iio_dev *indio_dev,
> +				struct iio_chan_spec const *chan,
> +				int *val, int *val2, long mask)
> +{
> +	int ret;
> +	struct jsa1212_data *data = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		mutex_lock(&data->lock);
> +		switch (chan->type) {
> +		case IIO_LIGHT:
> +			ret = jsa1212_read_als_data(data, val);
> +			break;
> +		case IIO_PROXIMITY:
> +			ret = jsa1212_read_pxs_data(data, val);
> +			break;
> +		default:
> +			ret = -EINVAL;
> +			break;
> +		}
You could simplify this a tiny bit by having the read functions return
IIO_VAL_INT on success, but it's probably not worth doing..

> +		ret = ret < 0 ? ret : IIO_VAL_INT;
> +		mutex_unlock(&data->lock);
> +		break;
> +	case IIO_CHAN_INFO_SCALE:
> +		switch (chan->type) {
> +		case IIO_LIGHT:
> +			*val = jsa1212_als_range_val[data->als_rng_idx];
> +			*val2 = BIT(12); /* Max 12 bit value */
> +			ret = IIO_VAL_FRACTIONAL;
> +			break;
> +		default:
> +			ret = -EINVAL;
> +			break;
> +		}
> +		break;
> +	default:
> +		ret = -EINVAL;
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +static const struct iio_chan_spec jsa1212_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 const struct iio_info jsa1212_info = {
> +	.driver_module		= THIS_MODULE,
> +	.read_raw		= &jsa1212_read_raw,
> +};
> +
> +static int jsa1212_chip_init(struct jsa1212_data *data)
> +{
> +	int ret;
> +
> +	ret = i2c_smbus_write_byte_data(data->client, JSA1212_CONF_REG,
> +					JSA1212_CONF_REG_DEF);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = i2c_smbus_write_byte_data(data->client, JSA1212_INT_REG,
> +					JSA1212_INT_REG_DEF);
> +	if (ret < 0)
> +		return ret;
> +
> +	data->als_rng_idx = JSA1212_ALS_RNG_0_2048;
> +	data->flags = 0x00;
This will already be true as it is created with a kzalloc call.
> +
> +	return 0;
> +}
> +
> +static int jsa1212_probe(struct i2c_client *client,
> +			     const struct i2c_device_id *id)
> +{
> +	struct jsa1212_data *jsa1212_data;
> +	struct iio_dev *indio_dev;
> +	int ret;
> +
> +	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
> +		return -ENODEV;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*jsa1212_data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	jsa1212_data = iio_priv(indio_dev);
> +
> +	i2c_set_clientdata(client, indio_dev);
> +	jsa1212_data->client = client;
> +
> +	mutex_init(&jsa1212_data->lock);
> +
> +	ret = jsa1212_chip_init(jsa1212_data);
> +	if (ret < 0)
> +		return ret;
> +
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->channels = jsa1212_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(jsa1212_channels);
> +	indio_dev->name = id->name;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	indio_dev->info = &jsa1212_info;
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "%s: register device failed\n", __func__);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int jsa1212_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +	struct jsa1212_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->lock);
> +
> +	ret = jsa1212_reg_update(data, JSA1212_CONF_REG,
> +			JSA1212_CONF_ALS_MASK |
> +			JSA1212_CONF_PXS_MASK,
> +			JSA1212_CONF_ALS_DISABLE |
> +			JSA1212_CONF_PXS_DISABLE);
> +
> +	if (ret < 0)
> +		dev_err(&client->dev, "power off cmd failed\n");
> +
> +	mutex_unlock(&data->lock);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	return ret;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int jsa1212_suspend(struct device *dev)
> +{
> +	int ret;
> +	struct jsa1212_data *data;
> +
> +	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
> +
> +	mutex_lock(&data->lock);
> +
> +	ret = jsa1212_reg_update(data, JSA1212_CONF_REG,
> +			JSA1212_CONF_ALS_MASK |
> +			JSA1212_CONF_PXS_MASK,
> +			JSA1212_CONF_ALS_DISABLE |
> +			JSA1212_CONF_PXS_DISABLE);
> +
> +	if (ret < 0)
> +		dev_err(dev, "suspend cmd failed\n");
> +
> +	mutex_unlock(&data->lock);
> +
> +	return ret;
Given the remove and the suspend have ended up pretty similar,
perhaps a utility function would cut down on code repitition?
> +}
> +
> +static int jsa1212_resume(struct device *dev)
> +{
> +	int ret = 0;
> +	struct jsa1212_data *data;
> +
> +	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
> +
> +	mutex_lock(&data->lock);
> +
> +	if (test_bit(JSA1212_OPMODE_ALS_EN, &data->flags)) {
> +		ret = jsa1212_als_enable(data, JSA1212_CONF_ALS_ENABLE);
> +		if (ret < 0) {
> +			dev_err(dev, "als resume failed\n");
> +			mutex_unlock(&data->lock);
> +			return ret;
> +		}
> +	}
> +
> +	if (test_bit(JSA1212_OPMODE_PXS_EN, &data->flags)) {
> +		ret = jsa1212_pxs_enable(data, JSA1212_CONF_PXS_ENABLE);
> +		if (ret < 0)
> +			dev_err(dev, "pxs resume failed\n");
> +	}
> +
> +	mutex_unlock(&data->lock);
> +
> +	return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(jsa1212_pm_ops, jsa1212_suspend, jsa1212_resume);
> +
> +#define JSA1212_PM_OPS (&jsa1212_pm_ops)
> +#else
> +#define JSA1212_PM_OPS NULL
> +#endif
> +
> +static const struct acpi_device_id jsa1212_acpi_match[] = {
> +	{"JSA1212", 0},
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(acpi, jsa1212_acpi_match);
> +
> +static const struct i2c_device_id jsa1212_id[] = {
> +	{ "jsa1212", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, jsa1212_id);
> +
> +static struct i2c_driver jsa1212_driver = {
> +	.driver = {
> +		.name	= "jsa1212",
> +		.pm	= JSA1212_PM_OPS,
> +		.owner	= THIS_MODULE,
> +		.acpi_match_table = ACPI_PTR(jsa1212_acpi_match),
> +	},
> +	.probe		= jsa1212_probe,
> +	.remove		= jsa1212_remove,
> +	.id_table	= jsa1212_id,
> +};
> +module_i2c_driver(jsa1212_driver);
> +
> +MODULE_AUTHOR("Sathya Kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com>");
> +MODULE_DESCRIPTION("JSA1212 proximity/ambient light sensor driver");
> +MODULE_LICENSE("GPL v2");
>