[linux-2.6-block.git] / drivers / hwmon / mcp3021.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * mcp3021.c - driver for Microchip MCP3021 and MCP3221
 *
 * Copyright (C) 2008-2009, 2012 Freescale Semiconductor, Inc.
 * Author: Mingkai Hu <Mingkai.hu@freescale.com>
 * Reworked by Sven Schuchmann <schuchmann@schleissheimer.de>
 * DT support added by Clemens Gruber <clemens.gruber@pqgruber.com>
 *
 * This driver exports the value of analog input voltage to sysfs, the
 * voltage unit is mV. Through the sysfs interface, lm-sensors tool
 * can also display the input voltage.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/hwmon.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/of.h>

/* Vdd / reference voltage in millivolt */
#define MCP3021_VDD_REF_MAX	5500
#define MCP3021_VDD_REF_MIN	2700
#define MCP3021_VDD_REF_DEFAULT	3300

/* output format */
#define MCP3021_SAR_SHIFT	2
#define MCP3021_SAR_MASK	0x3ff
#define MCP3021_OUTPUT_RES	10	/* 10-bit resolution */

#define MCP3221_SAR_SHIFT	0
#define MCP3221_SAR_MASK	0xfff
#define MCP3221_OUTPUT_RES	12	/* 12-bit resolution */

enum chips {
	mcp3021,
	mcp3221
};

/*
 * Client data (each client gets its own)
 */
struct mcp3021_data {
	struct i2c_client *client;
	u32 vdd;        /* supply and reference voltage in millivolt */
	u16 sar_shift;
	u16 sar_mask;
	u8 output_res;
};

static inline u16 volts_from_reg(struct mcp3021_data *data, u16 val)
{
	return DIV_ROUND_CLOSEST(data->vdd * val, 1 << data->output_res);
}

static int mcp3021_read(struct device *dev, enum hwmon_sensor_types type,
			u32 attr, int channel, long *val)
{
	struct mcp3021_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	__be16 buf;
	u16 reg;
	int ret;

	if (type != hwmon_in)
		return -EOPNOTSUPP;

	ret = i2c_master_recv(client, (char *)&buf, 2);
	if (ret < 0)
		return ret;
	if (ret != 2)
		return -EIO;

	/* The output code of the MCP3021 is transmitted with MSB first. */
	reg = be16_to_cpu(buf);

	/*
	 * The ten-bit output code is composed of the lower 4-bit of the
	 * first byte and the upper 6-bit of the second byte.
	 */
	reg = (reg >> data->sar_shift) & data->sar_mask;

	*val = volts_from_reg(data, reg);

	return 0;
}

static umode_t mcp3021_is_visible(const void *_data,
				  enum hwmon_sensor_types type,
				  u32 attr, int channel)
{
	if (type != hwmon_in)
		return 0;

	if (attr != hwmon_in_input)
		return 0;

	return 0444;
}

static const struct hwmon_channel_info * const mcp3021_info[] = {
	HWMON_CHANNEL_INFO(in, HWMON_I_INPUT),
	NULL
};

static const struct hwmon_ops mcp3021_hwmon_ops = {
	.is_visible = mcp3021_is_visible,
	.read = mcp3021_read,
};

static const struct hwmon_chip_info mcp3021_chip_info = {
	.ops = &mcp3021_hwmon_ops,
	.info = mcp3021_info,
};

static const struct i2c_device_id mcp3021_id[];

static int mcp3021_probe(struct i2c_client *client)
{
	struct mcp3021_data *data = NULL;
	struct device_node *np = client->dev.of_node;
	struct device *hwmon_dev;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
		return -ENODEV;

	data = devm_kzalloc(&client->dev, sizeof(struct mcp3021_data),
			    GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	i2c_set_clientdata(client, data);

	if (np) {
		if (!of_property_read_u32(np, "reference-voltage-microvolt",
					  &data->vdd))
			data->vdd /= 1000;
		else
			data->vdd = MCP3021_VDD_REF_DEFAULT;
	} else {
		u32 *pdata = dev_get_platdata(&client->dev);

		if (pdata)
			data->vdd = *pdata;
		else
			data->vdd = MCP3021_VDD_REF_DEFAULT;
	}

	switch (i2c_match_id(mcp3021_id, client)->driver_data) {
	case mcp3021:
		data->sar_shift = MCP3021_SAR_SHIFT;
		data->sar_mask = MCP3021_SAR_MASK;
		data->output_res = MCP3021_OUTPUT_RES;
		break;

	case mcp3221:
		data->sar_shift = MCP3221_SAR_SHIFT;
		data->sar_mask = MCP3221_SAR_MASK;
		data->output_res = MCP3221_OUTPUT_RES;
		break;
	}

	data->client = client;

	if (data->vdd > MCP3021_VDD_REF_MAX || data->vdd < MCP3021_VDD_REF_MIN)
		return -EINVAL;

	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
							 client->name,
							 data,
							 &mcp3021_chip_info,
							 NULL);
	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static const struct i2c_device_id mcp3021_id[] = {
	{ "mcp3021", mcp3021 },
	{ "mcp3221", mcp3221 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, mcp3021_id);

#ifdef CONFIG_OF
static const struct of_device_id of_mcp3021_match[] = {
	{ .compatible = "microchip,mcp3021", .data = (void *)mcp3021 },
	{ .compatible = "microchip,mcp3221", .data = (void *)mcp3221 },
	{ }
};
MODULE_DEVICE_TABLE(of, of_mcp3021_match);
#endif

static struct i2c_driver mcp3021_driver = {
	.driver = {
		.name = "mcp3021",
		.of_match_table = of_match_ptr(of_mcp3021_match),
	},
	.probe = mcp3021_probe,
	.id_table = mcp3021_id,
};

module_i2c_driver(mcp3021_driver);

MODULE_AUTHOR("Mingkai Hu <Mingkai.hu@freescale.com>");
MODULE_DESCRIPTION("Microchip MCP3021/MCP3221 driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
5510e62a	2	/*
592758b1	3	* mcp3021.c - driver for Microchip MCP3021 and MCP3221
5510e62a XX	4	*
	5	* Copyright (C) 2008-2009, 2012 Freescale Semiconductor, Inc.
	6	* Author: Mingkai Hu <Mingkai.hu@freescale.com>
8b662f38	7	* Reworked by Sven Schuchmann <schuchmann@schleissheimer.de>
f4dc811c	8	* DT support added by Clemens Gruber <clemens.gruber@pqgruber.com>
5510e62a	9	*
03508eea	10	* This driver exports the value of analog input voltage to sysfs, the
5510e62a XX	11	* voltage unit is mV. Through the sysfs interface, lm-sensors tool
5510e62a XX	12	* can also display the input voltage.
5510e62a XX	13	*/
	14
	15	#include <linux/kernel.h>
	16	#include <linux/module.h>
	17	#include <linux/hwmon.h>
	18	#include <linux/slab.h>
	19	#include <linux/i2c.h>
	20	#include <linux/err.h>
	21	#include <linux/device.h>
f4dc811c	22	#include <linux/of.h>
5510e62a	23
f4dc811c CG	24	/* Vdd / reference voltage in millivolt */
	25	#define MCP3021_VDD_REF_MAX 5500
	26	#define MCP3021_VDD_REF_MIN 2700
	27	#define MCP3021_VDD_REF_DEFAULT 3300
5510e62a XX	28
	29	/* output format */
	30	#define MCP3021_SAR_SHIFT 2
	31	#define MCP3021_SAR_MASK 0x3ff
5510e62a	32	#define MCP3021_OUTPUT_RES 10 /* 10-bit resolution */
5510e62a	33
592758b1 SS	34	#define MCP3221_SAR_SHIFT 0
	35	#define MCP3221_SAR_MASK 0xfff
	36	#define MCP3221_OUTPUT_RES 12 /* 12-bit resolution */
592758b1	37
8b662f38	38	enum chips {
592758b1 SS	39	mcp3021,
592758b1 SS	40	mcp3221
8b662f38	41	};
592758b1	42
5510e62a XX	43	/*
	44	* Client data (each client gets its own)
	45	*/
	46	struct mcp3021_data {
03508eea	47	struct i2c_client *client;
f4dc811c	48	u32 vdd; /* supply and reference voltage in millivolt */
8b662f38 SS	49	u16 sar_shift;
	50	u16 sar_mask;
	51	u8 output_res;
5510e62a XX	52	};
5510e62a XX	53
03508eea	54	static inline u16 volts_from_reg(struct mcp3021_data *data, u16 val)
5510e62a	55	{
03508eea MF	56	return DIV_ROUND_CLOSEST(data->vdd * val, 1 << data->output_res);
	57	}
	58
	59	static int mcp3021_read(struct device *dev, enum hwmon_sensor_types type,
	60	u32 attr, int channel, long *val)
	61	{
	62	struct mcp3021_data *data = dev_get_drvdata(dev);
	63	struct i2c_client *client = data->client;
5510e62a	64	__be16 buf;
03508eea MF	65	u16 reg;
	66	int ret;
	67
	68	if (type != hwmon_in)
	69	return -EOPNOTSUPP;
5510e62a XX	70
	71	ret = i2c_master_recv(client, (char *)&buf, 2);
	72	if (ret < 0)
	73	return ret;
	74	if (ret != 2)
	75	return -EIO;
	76
	77	/* The output code of the MCP3021 is transmitted with MSB first. */
	78	reg = be16_to_cpu(buf);
	79
	80	/*
	81	* The ten-bit output code is composed of the lower 4-bit of the
	82	* first byte and the upper 6-bit of the second byte.
	83	*/
8b662f38	84	reg = (reg >> data->sar_shift) & data->sar_mask;
5510e62a	85
03508eea	86	*val = volts_from_reg(data, reg);
5510e62a	87
03508eea	88	return 0;
5510e62a XX	89	}
5510e62a XX	90
03508eea MF	91	static umode_t mcp3021_is_visible(const void *_data,
	92	enum hwmon_sensor_types type,
	93	u32 attr, int channel)
5510e62a	94	{
03508eea MF	95	if (type != hwmon_in)
03508eea MF	96	return 0;
5510e62a	97
03508eea MF	98	if (attr != hwmon_in_input)
03508eea MF	99	return 0;
5510e62a	100
03508eea	101	return 0444;
5510e62a XX	102	}
5510e62a XX	103
d716e0cf	104	static const struct hwmon_channel_info * const mcp3021_info[] = {
03508eea MF	105	HWMON_CHANNEL_INFO(in, HWMON_I_INPUT),
	106	NULL
	107	};
	108
	109	static const struct hwmon_ops mcp3021_hwmon_ops = {
	110	.is_visible = mcp3021_is_visible,
	111	.read = mcp3021_read,
	112	};
	113
	114	static const struct hwmon_chip_info mcp3021_chip_info = {
	115	.ops = &mcp3021_hwmon_ops,
	116	.info = mcp3021_info,
	117	};
5510e62a	118
67487038 SK	119	static const struct i2c_device_id mcp3021_id[];
	120
	121	static int mcp3021_probe(struct i2c_client *client)
5510e62a	122	{
5510e62a	123	struct mcp3021_data *data = NULL;
f4dc811c	124	struct device_node *np = client->dev.of_node;
03508eea	125	struct device *hwmon_dev;
5510e62a XX	126
	127	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	128	return -ENODEV;
	129
79831fd4 GR	130	data = devm_kzalloc(&client->dev, sizeof(struct mcp3021_data),
79831fd4 GR	131	GFP_KERNEL);
5510e62a XX	132	if (!data)
	133	return -ENOMEM;
	134
	135	i2c_set_clientdata(client, data);
	136
f4dc811c CG	137	if (np) {
	138	if (!of_property_read_u32(np, "reference-voltage-microvolt",
	139	&data->vdd))
	140	data->vdd /= 1000;
	141	else
	142	data->vdd = MCP3021_VDD_REF_DEFAULT;
	143	} else {
	144	u32 *pdata = dev_get_platdata(&client->dev);
	145
	146	if (pdata)
	147	data->vdd = *pdata;
	148	else
	149	data->vdd = MCP3021_VDD_REF_DEFAULT;
	150	}
	151
67487038	152	switch (i2c_match_id(mcp3021_id, client)->driver_data) {
8b662f38 SS	153	case mcp3021:
	154	data->sar_shift = MCP3021_SAR_SHIFT;
	155	data->sar_mask = MCP3021_SAR_MASK;
	156	data->output_res = MCP3021_OUTPUT_RES;
8b662f38	157	break;
592758b1 SS	158
	159	case mcp3221:
	160	data->sar_shift = MCP3221_SAR_SHIFT;
	161	data->sar_mask = MCP3221_SAR_MASK;
	162	data->output_res = MCP3221_OUTPUT_RES;
592758b1	163	break;
8b662f38 SS	164	}
8b662f38 SS	165
03508eea MF	166	data->client = client;
03508eea MF	167
f4dc811c CG	168	if (data->vdd > MCP3021_VDD_REF_MAX \|\| data->vdd < MCP3021_VDD_REF_MIN)
f4dc811c CG	169	return -EINVAL;
5510e62a	170
03508eea MF	171	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
	172	client->name,
	173	data,
	174	&mcp3021_chip_info,
	175	NULL);
	176	return PTR_ERR_OR_ZERO(hwmon_dev);
5510e62a XX	177	}
	178
	179	static const struct i2c_device_id mcp3021_id[] = {
8b662f38	180	{ "mcp3021", mcp3021 },
592758b1	181	{ "mcp3221", mcp3221 },
5510e62a XX	182	{ }
	183	};
	184	MODULE_DEVICE_TABLE(i2c, mcp3021_id);
	185
f4dc811c CG	186	#ifdef CONFIG_OF
	187	static const struct of_device_id of_mcp3021_match[] = {
	188	{ .compatible = "microchip,mcp3021", .data = (void *)mcp3021 },
	189	{ .compatible = "microchip,mcp3221", .data = (void *)mcp3221 },
	190	{ }
	191	};
	192	MODULE_DEVICE_TABLE(of, of_mcp3021_match);
	193	#endif
	194
5510e62a XX	195	static struct i2c_driver mcp3021_driver = {
	196	.driver = {
	197	.name = "mcp3021",
f4dc811c	198	.of_match_table = of_match_ptr(of_mcp3021_match),
5510e62a	199	},
1975d167	200	.probe = mcp3021_probe,
5510e62a XX	201	.id_table = mcp3021_id,
	202	};
	203
	204	module_i2c_driver(mcp3021_driver);
	205
	206	MODULE_AUTHOR("Mingkai Hu <Mingkai.hu@freescale.com>");
592758b1	207	MODULE_DESCRIPTION("Microchip MCP3021/MCP3221 driver");
5510e62a	208	MODULE_LICENSE("GPL");