[linux-block.git] / drivers / hwmon / ads7828.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * ads7828.c - driver for TI ADS7828 8-channel A/D converter and compatibles
 * (C) 2007 EADS Astrium
 *
 * This driver is based on the lm75 and other lm_sensors/hwmon drivers
 *
 * Written by Steve Hardy <shardy@redhat.com>
 *
 * ADS7830 support, by Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
 *
 * For further information, see the Documentation/hwmon/ads7828.rst file.
 */

#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_data/ads7828.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/regulator/consumer.h>

/* The ADS7828 registers */
#define ADS7828_CMD_SD_SE	0x80	/* Single ended inputs */
#define ADS7828_CMD_PD1		0x04	/* Internal vref OFF && A/D ON */
#define ADS7828_CMD_PD3		0x0C	/* Internal vref ON && A/D ON */
#define ADS7828_INT_VREF_MV	2500	/* Internal vref is 2.5V, 2500mV */
#define ADS7828_EXT_VREF_MV_MIN	50	/* External vref min value 0.05V */
#define ADS7828_EXT_VREF_MV_MAX	5250	/* External vref max value 5.25V */

/* List of supported devices */
enum ads7828_chips { ads7828, ads7830 };

/* Client specific data */
struct ads7828_data {
	struct regmap *regmap;
	u8 cmd_byte;			/* Command byte without channel bits */
	unsigned int lsb_resol;		/* Resolution of the ADC sample LSB */
};

/* Command byte C2,C1,C0 - see datasheet */
static inline u8 ads7828_cmd_byte(u8 cmd, int ch)
{
	return cmd | (((ch >> 1) | (ch & 0x01) << 2) << 4);
}

/* sysfs callback function */
static ssize_t ads7828_in_show(struct device *dev,
			       struct device_attribute *da, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct ads7828_data *data = dev_get_drvdata(dev);
	u8 cmd = ads7828_cmd_byte(data->cmd_byte, attr->index);
	unsigned int regval;
	int err;

	err = regmap_read(data->regmap, cmd, &regval);
	if (err < 0)
		return err;

	return sprintf(buf, "%d\n",
		       DIV_ROUND_CLOSEST(regval * data->lsb_resol, 1000));
}

static SENSOR_DEVICE_ATTR_RO(in0_input, ads7828_in, 0);
static SENSOR_DEVICE_ATTR_RO(in1_input, ads7828_in, 1);
static SENSOR_DEVICE_ATTR_RO(in2_input, ads7828_in, 2);
static SENSOR_DEVICE_ATTR_RO(in3_input, ads7828_in, 3);
static SENSOR_DEVICE_ATTR_RO(in4_input, ads7828_in, 4);
static SENSOR_DEVICE_ATTR_RO(in5_input, ads7828_in, 5);
static SENSOR_DEVICE_ATTR_RO(in6_input, ads7828_in, 6);
static SENSOR_DEVICE_ATTR_RO(in7_input, ads7828_in, 7);

static struct attribute *ads7828_attrs[] = {
	&sensor_dev_attr_in0_input.dev_attr.attr,
	&sensor_dev_attr_in1_input.dev_attr.attr,
	&sensor_dev_attr_in2_input.dev_attr.attr,
	&sensor_dev_attr_in3_input.dev_attr.attr,
	&sensor_dev_attr_in4_input.dev_attr.attr,
	&sensor_dev_attr_in5_input.dev_attr.attr,
	&sensor_dev_attr_in6_input.dev_attr.attr,
	&sensor_dev_attr_in7_input.dev_attr.attr,
	NULL
};

ATTRIBUTE_GROUPS(ads7828);

static const struct regmap_config ads2828_regmap_config = {
	.reg_bits = 8,
	.val_bits = 16,
};

static const struct regmap_config ads2830_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
};

static int ads7828_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct ads7828_platform_data *pdata = dev_get_platdata(dev);
	struct ads7828_data *data;
	struct device *hwmon_dev;
	unsigned int vref_mv = ADS7828_INT_VREF_MV;
	unsigned int vref_uv;
	bool diff_input = false;
	bool ext_vref = false;
	unsigned int regval;
	enum ads7828_chips chip;
	struct regulator *reg;

	data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	if (pdata) {
		diff_input = pdata->diff_input;
		ext_vref = pdata->ext_vref;
		if (ext_vref && pdata->vref_mv)
			vref_mv = pdata->vref_mv;
	} else if (dev->of_node) {
		diff_input = of_property_read_bool(dev->of_node,
						   "ti,differential-input");
		reg = devm_regulator_get_optional(dev, "vref");
		if (!IS_ERR(reg)) {
			vref_uv = regulator_get_voltage(reg);
			vref_mv = DIV_ROUND_CLOSEST(vref_uv, 1000);
			if (vref_mv < ADS7828_EXT_VREF_MV_MIN ||
			    vref_mv > ADS7828_EXT_VREF_MV_MAX)
				return -EINVAL;
			ext_vref = true;
		}
	}

	if (client->dev.of_node)
		chip = (enum ads7828_chips)
			of_device_get_match_data(&client->dev);
	else
		chip = id->driver_data;

	/* Bound Vref with min/max values */
	vref_mv = clamp_val(vref_mv, ADS7828_EXT_VREF_MV_MIN,
			    ADS7828_EXT_VREF_MV_MAX);

	/* ADS7828 uses 12-bit samples, while ADS7830 is 8-bit */
	if (chip == ads7828) {
		data->lsb_resol = DIV_ROUND_CLOSEST(vref_mv * 1000, 4096);
		data->regmap = devm_regmap_init_i2c(client,
						    &ads2828_regmap_config);
	} else {
		data->lsb_resol = DIV_ROUND_CLOSEST(vref_mv * 1000, 256);
		data->regmap = devm_regmap_init_i2c(client,
						    &ads2830_regmap_config);
	}

	if (IS_ERR(data->regmap))
		return PTR_ERR(data->regmap);

	data->cmd_byte = ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3;
	if (!diff_input)
		data->cmd_byte |= ADS7828_CMD_SD_SE;

	/*
	 * Datasheet specifies internal reference voltage is disabled by
	 * default. The internal reference voltage needs to be enabled and
	 * voltage needs to settle before getting valid ADC data. So perform a
	 * dummy read to enable the internal reference voltage.
	 */
	if (!ext_vref)
		regmap_read(data->regmap, data->cmd_byte, &regval);

	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
							   data,
							   ads7828_groups);
	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static const struct i2c_device_id ads7828_device_ids[] = {
	{ "ads7828", ads7828 },
	{ "ads7830", ads7830 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ads7828_device_ids);

static const struct of_device_id __maybe_unused ads7828_of_match[] = {
	{
		.compatible = "ti,ads7828",
		.data = (void *)ads7828
	},
	{
		.compatible = "ti,ads7830",
		.data = (void *)ads7830
	},
	{ },
};
MODULE_DEVICE_TABLE(of, ads7828_of_match);

static struct i2c_driver ads7828_driver = {
	.driver = {
		.name = "ads7828",
		.of_match_table = of_match_ptr(ads7828_of_match),
	},

	.id_table = ads7828_device_ids,
	.probe = ads7828_probe,
};

module_i2c_driver(ads7828_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steve Hardy <shardy@redhat.com>");
MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter and compatibles");
Commit	Line	Data
74ba9207	1	// SPDX-License-Identifier: GPL-2.0-or-later
5812f928	2	/*
0962e0f1	3	* ads7828.c - driver for TI ADS7828 8-channel A/D converter and compatibles
d13d6232 GR	4	* (C) 2007 EADS Astrium
	5	*
	6	* This driver is based on the lm75 and other lm_sensors/hwmon drivers
	7	*
	8	* Written by Steve Hardy <shardy@redhat.com>
	9	*
0962e0f1 GR	10	* ADS7830 support, by Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
0962e0f1 GR	11	*
7ebd8b66	12	* For further information, see the Documentation/hwmon/ads7828.rst file.
d13d6232	13	*/
5812f928	14
46d78462	15	#include <linux/err.h>
5812f928 SH	16	#include <linux/hwmon.h>
5812f928 SH	17	#include <linux/hwmon-sysfs.h>
46d78462 VD	18	#include <linux/i2c.h>
46d78462 VD	19	#include <linux/init.h>
46d78462	20	#include <linux/module.h>
2d688f14	21	#include <linux/of_device.h>
46d78462	22	#include <linux/platform_data/ads7828.h>
bea0bab0	23	#include <linux/regmap.h>
46d78462	24	#include <linux/slab.h>
a8ddfea0	25	#include <linux/regulator/consumer.h>
5812f928 SH	26
5812f928 SH	27	/* The ADS7828 registers */
46d78462 VD	28	#define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */
	29	#define ADS7828_CMD_PD1 0x04 /* Internal vref OFF && A/D ON */
	30	#define ADS7828_CMD_PD3 0x0C /* Internal vref ON && A/D ON */
	31	#define ADS7828_INT_VREF_MV 2500 /* Internal vref is 2.5V, 2500mV */
	32	#define ADS7828_EXT_VREF_MV_MIN 50 /* External vref min value 0.05V */
	33	#define ADS7828_EXT_VREF_MV_MAX 5250 /* External vref max value 5.25V */
	34
0962e0f1 GR	35	/* List of supported devices */
	36	enum ads7828_chips { ads7828, ads7830 };
	37
46d78462	38	/* Client specific data */
5812f928	39	struct ads7828_data {
bea0bab0	40	struct regmap *regmap;
46d78462 VD	41	u8 cmd_byte; /* Command byte without channel bits */
46d78462 VD	42	unsigned int lsb_resol; /* Resolution of the ADC sample LSB */
5812f928 SH	43	};
5812f928 SH	44
46d78462 VD	45	/* Command byte C2,C1,C0 - see datasheet */
46d78462 VD	46	static inline u8 ads7828_cmd_byte(u8 cmd, int ch)
5812f928	47	{
46d78462	48	return cmd \| (((ch >> 1) \| (ch & 0x01) << 2) << 4);
5812f928 SH	49	}
5812f928 SH	50
5812f928	51	/* sysfs callback function */
3ecd2783 GR	52	static ssize_t ads7828_in_show(struct device *dev,
3ecd2783 GR	53	struct device_attribute da, char buf)
5812f928 SH	54	{
5812f928 SH	55	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
bea0bab0 GR	56	struct ads7828_data *data = dev_get_drvdata(dev);
	57	u8 cmd = ads7828_cmd_byte(data->cmd_byte, attr->index);
	58	unsigned int regval;
	59	int err;
5812f928	60
bea0bab0 GR	61	err = regmap_read(data->regmap, cmd, &regval);
	62	if (err < 0)
	63	return err;
	64
	65	return sprintf(buf, "%d\n",
	66	DIV_ROUND_CLOSEST(regval * data->lsb_resol, 1000));
46d78462	67	}
5812f928	68
3ecd2783 GR	69	static SENSOR_DEVICE_ATTR_RO(in0_input, ads7828_in, 0);
	70	static SENSOR_DEVICE_ATTR_RO(in1_input, ads7828_in, 1);
	71	static SENSOR_DEVICE_ATTR_RO(in2_input, ads7828_in, 2);
	72	static SENSOR_DEVICE_ATTR_RO(in3_input, ads7828_in, 3);
	73	static SENSOR_DEVICE_ATTR_RO(in4_input, ads7828_in, 4);
	74	static SENSOR_DEVICE_ATTR_RO(in5_input, ads7828_in, 5);
	75	static SENSOR_DEVICE_ATTR_RO(in6_input, ads7828_in, 6);
	76	static SENSOR_DEVICE_ATTR_RO(in7_input, ads7828_in, 7);
5812f928	77
f82b2c34	78	static struct attribute *ads7828_attrs[] = {
5812f928 SH	79	&sensor_dev_attr_in0_input.dev_attr.attr,
	80	&sensor_dev_attr_in1_input.dev_attr.attr,
	81	&sensor_dev_attr_in2_input.dev_attr.attr,
	82	&sensor_dev_attr_in3_input.dev_attr.attr,
	83	&sensor_dev_attr_in4_input.dev_attr.attr,
	84	&sensor_dev_attr_in5_input.dev_attr.attr,
	85	&sensor_dev_attr_in6_input.dev_attr.attr,
	86	&sensor_dev_attr_in7_input.dev_attr.attr,
	87	NULL
	88	};
	89
f82b2c34	90	ATTRIBUTE_GROUPS(ads7828);
5812f928	91
bea0bab0 GR	92	static const struct regmap_config ads2828_regmap_config = {
	93	.reg_bits = 8,
	94	.val_bits = 16,
	95	};
	96
	97	static const struct regmap_config ads2830_regmap_config = {
	98	.reg_bits = 8,
	99	.val_bits = 8,
	100	};
	101
7347cb38 JD	102	static int ads7828_probe(struct i2c_client *client,
	103	const struct i2c_device_id *id)
	104	{
f82b2c34 AL	105	struct device *dev = &client->dev;
f82b2c34 AL	106	struct ads7828_platform_data *pdata = dev_get_platdata(dev);
7347cb38	107	struct ads7828_data *data;
f82b2c34	108	struct device *hwmon_dev;
7f444bf0	109	unsigned int vref_mv = ADS7828_INT_VREF_MV;
a8ddfea0	110	unsigned int vref_uv;
7f444bf0 GR	111	bool diff_input = false;
7f444bf0 GR	112	bool ext_vref = false;
7a18afe8	113	unsigned int regval;
2d688f14	114	enum ads7828_chips chip;
a8ddfea0	115	struct regulator *reg;
5812f928	116
f82b2c34	117	data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL);
34e3f7f5 GR	118	if (!data)
34e3f7f5 GR	119	return -ENOMEM;
5812f928	120
46d78462	121	if (pdata) {
7f444bf0 GR	122	diff_input = pdata->diff_input;
	123	ext_vref = pdata->ext_vref;
	124	if (ext_vref && pdata->vref_mv)
	125	vref_mv = pdata->vref_mv;
a8ddfea0 SP	126	} else if (dev->of_node) {
	127	diff_input = of_property_read_bool(dev->of_node,
	128	"ti,differential-input");
	129	reg = devm_regulator_get_optional(dev, "vref");
	130	if (!IS_ERR(reg)) {
	131	vref_uv = regulator_get_voltage(reg);
	132	vref_mv = DIV_ROUND_CLOSEST(vref_uv, 1000);
	133	if (vref_mv < ADS7828_EXT_VREF_MV_MIN \|\|
	134	vref_mv > ADS7828_EXT_VREF_MV_MAX)
	135	return -EINVAL;
	136	ext_vref = true;
	137	}
46d78462 VD	138	}
46d78462 VD	139
2d688f14 JMC	140	if (client->dev.of_node)
	141	chip = (enum ads7828_chips)
	142	of_device_get_match_data(&client->dev);
	143	else
	144	chip = id->driver_data;
	145
7f444bf0 GR	146	/* Bound Vref with min/max values */
	147	vref_mv = clamp_val(vref_mv, ADS7828_EXT_VREF_MV_MIN,
	148	ADS7828_EXT_VREF_MV_MAX);
46d78462	149
0962e0f1	150	/* ADS7828 uses 12-bit samples, while ADS7830 is 8-bit */
2d688f14	151	if (chip == ads7828) {
7f444bf0	152	data->lsb_resol = DIV_ROUND_CLOSEST(vref_mv * 1000, 4096);
bea0bab0 GR	153	data->regmap = devm_regmap_init_i2c(client,
bea0bab0 GR	154	&ads2828_regmap_config);
0962e0f1	155	} else {
7f444bf0	156	data->lsb_resol = DIV_ROUND_CLOSEST(vref_mv * 1000, 256);
bea0bab0 GR	157	data->regmap = devm_regmap_init_i2c(client,
bea0bab0 GR	158	&ads2830_regmap_config);
0962e0f1	159	}
46d78462	160
d9ef72cd AL	161	if (IS_ERR(data->regmap))
	162	return PTR_ERR(data->regmap);
	163
7f444bf0 GR	164	data->cmd_byte = ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3;
7f444bf0 GR	165	if (!diff_input)
46d78462 VD	166	data->cmd_byte \|= ADS7828_CMD_SD_SE;
46d78462 VD	167
7a18afe8 AB	168	/*
	169	* Datasheet specifies internal reference voltage is disabled by
	170	* default. The internal reference voltage needs to be enabled and
	171	* voltage needs to settle before getting valid ADC data. So perform a
	172	* dummy read to enable the internal reference voltage.
	173	*/
	174	if (!ext_vref)
	175	regmap_read(data->regmap, data->cmd_byte, &regval);
	176
f82b2c34 AL	177	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
	178	data,
	179	ads7828_groups);
	180	return PTR_ERR_OR_ZERO(hwmon_dev);
5812f928 SH	181	}
5812f928 SH	182
46d78462	183	static const struct i2c_device_id ads7828_device_ids[] = {
0962e0f1 GR	184	{ "ads7828", ads7828 },
0962e0f1 GR	185	{ "ads7830", ads7830 },
46d78462 VD	186	{ }
	187	};
	188	MODULE_DEVICE_TABLE(i2c, ads7828_device_ids);
5812f928	189
0337dd9b	190	static const struct of_device_id __maybe_unused ads7828_of_match[] = {
2d688f14 JMC	191	{
	192	.compatible = "ti,ads7828",
	193	.data = (void *)ads7828
	194	},
	195	{
	196	.compatible = "ti,ads7830",
	197	.data = (void *)ads7830
	198	},
	199	{ },
	200	};
	201	MODULE_DEVICE_TABLE(of, ads7828_of_match);
	202
46d78462 VD	203	static struct i2c_driver ads7828_driver = {
	204	.driver = {
	205	.name = "ads7828",
2d688f14	206	.of_match_table = of_match_ptr(ads7828_of_match),
46d78462	207	},
5812f928	208
46d78462 VD	209	.id_table = ads7828_device_ids,
46d78462 VD	210	.probe = ads7828_probe,
46d78462	211	};
5812f928	212
46d78462	213	module_i2c_driver(ads7828_driver);
5812f928	214
5812f928	215	MODULE_LICENSE("GPL");
46d78462	216	MODULE_AUTHOR("Steve Hardy <shardy@redhat.com>");
0962e0f1	217	MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter and compatibles");