[mirror_ubuntu-bionic-kernel.git] / drivers / hwmon / mcp3021.c

/*
 * 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 export 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.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#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>
#include <linux/of_device.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 device *hwmon_dev;
	u32 vdd;        /* supply and reference voltage in millivolt */
	u16 sar_shift;
	u16 sar_mask;
	u8 output_res;
};

static int mcp3021_read16(struct i2c_client *client)
{
	struct mcp3021_data *data = i2c_get_clientdata(client);
	int ret;
	u16 reg;
	__be16 buf;

	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;

	return reg;
}

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

static ssize_t in0_input_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct mcp3021_data *data = i2c_get_clientdata(client);
	int reg, in_input;

	reg = mcp3021_read16(client);
	if (reg < 0)
		return reg;

	in_input = volts_from_reg(data, reg);

	return sprintf(buf, "%d\n", in_input);
}

static DEVICE_ATTR_RO(in0_input);

static int mcp3021_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	int err;
	struct mcp3021_data *data = NULL;
	struct device_node *np = client->dev.of_node;

	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 (id->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;
	}

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

	err = sysfs_create_file(&client->dev.kobj, &dev_attr_in0_input.attr);
	if (err)
		return err;

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(data->hwmon_dev)) {
		err = PTR_ERR(data->hwmon_dev);
		goto exit_remove;
	}

	return 0;

exit_remove:
	sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr);
	return err;
}

static int mcp3021_remove(struct i2c_client *client)
{
	struct mcp3021_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr);

	return 0;
}

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,
	.remove = mcp3021_remove,
	.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
5510e62a	1	/*
592758b1	2	* mcp3021.c - driver for Microchip MCP3021 and MCP3221
5510e62a XX	3	*
	4	* Copyright (C) 2008-2009, 2012 Freescale Semiconductor, Inc.
	5	* Author: Mingkai Hu <Mingkai.hu@freescale.com>
8b662f38	6	* Reworked by Sven Schuchmann <schuchmann@schleissheimer.de>
f4dc811c	7	* DT support added by Clemens Gruber <clemens.gruber@pqgruber.com>
5510e62a XX	8	*
	9	* This driver export the value of analog input voltage to sysfs, the
	10	* voltage unit is mV. Through the sysfs interface, lm-sensors tool
	11	* can also display the input voltage.
	12	*
	13	* This program is free software; you can redistribute it and/or modify
	14	* it under the terms of the GNU General Public License as published by
	15	* the Free Software Foundation; either version 2 of the License, or
	16	* (at your option) any later version.
	17	*/
	18
	19	#include <linux/kernel.h>
	20	#include <linux/module.h>
	21	#include <linux/hwmon.h>
	22	#include <linux/slab.h>
	23	#include <linux/i2c.h>
	24	#include <linux/err.h>
	25	#include <linux/device.h>
f4dc811c CG	26	#include <linux/of.h>
f4dc811c CG	27	#include <linux/of_device.h>
5510e62a	28
f4dc811c CG	29	/* Vdd / reference voltage in millivolt */
	30	#define MCP3021_VDD_REF_MAX 5500
	31	#define MCP3021_VDD_REF_MIN 2700
	32	#define MCP3021_VDD_REF_DEFAULT 3300
5510e62a XX	33
	34	/* output format */
	35	#define MCP3021_SAR_SHIFT 2
	36	#define MCP3021_SAR_MASK 0x3ff
5510e62a	37	#define MCP3021_OUTPUT_RES 10 /* 10-bit resolution */
5510e62a	38
592758b1 SS	39	#define MCP3221_SAR_SHIFT 0
	40	#define MCP3221_SAR_MASK 0xfff
	41	#define MCP3221_OUTPUT_RES 12 /* 12-bit resolution */
592758b1	42
8b662f38	43	enum chips {
592758b1 SS	44	mcp3021,
592758b1 SS	45	mcp3221
8b662f38	46	};
592758b1	47
5510e62a XX	48	/*
	49	* Client data (each client gets its own)
	50	*/
	51	struct mcp3021_data {
	52	struct device *hwmon_dev;
f4dc811c	53	u32 vdd; /* supply and reference voltage in millivolt */
8b662f38 SS	54	u16 sar_shift;
	55	u16 sar_mask;
	56	u8 output_res;
5510e62a XX	57	};
	58
	59	static int mcp3021_read16(struct i2c_client *client)
	60	{
8b662f38	61	struct mcp3021_data *data = i2c_get_clientdata(client);
5510e62a XX	62	int ret;
	63	u16 reg;
	64	__be16 buf;
	65
	66	ret = i2c_master_recv(client, (char *)&buf, 2);
	67	if (ret < 0)
	68	return ret;
	69	if (ret != 2)
	70	return -EIO;
	71
	72	/* The output code of the MCP3021 is transmitted with MSB first. */
	73	reg = be16_to_cpu(buf);
	74
	75	/*
	76	* The ten-bit output code is composed of the lower 4-bit of the
	77	* first byte and the upper 6-bit of the second byte.
	78	*/
8b662f38	79	reg = (reg >> data->sar_shift) & data->sar_mask;
5510e62a XX	80
	81	return reg;
	82	}
	83
8b662f38	84	static inline u16 volts_from_reg(struct mcp3021_data *data, u16 val)
5510e62a	85	{
347d7e45	86	return DIV_ROUND_CLOSEST(data->vdd * val, 1 << data->output_res);
5510e62a XX	87	}
5510e62a XX	88
5c2f0dd5 JL	89	static ssize_t in0_input_show(struct device *dev,
5c2f0dd5 JL	90	struct device_attribute attr, char buf)
5510e62a XX	91	{
	92	struct i2c_client *client = to_i2c_client(dev);
	93	struct mcp3021_data *data = i2c_get_clientdata(client);
	94	int reg, in_input;
	95
	96	reg = mcp3021_read16(client);
	97	if (reg < 0)
	98	return reg;
	99
8b662f38 SS	100	in_input = volts_from_reg(data, reg);
8b662f38 SS	101
5510e62a XX	102	return sprintf(buf, "%d\n", in_input);
	103	}
	104
5c2f0dd5	105	static DEVICE_ATTR_RO(in0_input);
5510e62a XX	106
	107	static int mcp3021_probe(struct i2c_client *client,
	108	const struct i2c_device_id *id)
	109	{
	110	int err;
	111	struct mcp3021_data *data = NULL;
f4dc811c	112	struct device_node *np = client->dev.of_node;
5510e62a XX	113
	114	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	115	return -ENODEV;
	116
79831fd4 GR	117	data = devm_kzalloc(&client->dev, sizeof(struct mcp3021_data),
79831fd4 GR	118	GFP_KERNEL);
5510e62a XX	119	if (!data)
	120	return -ENOMEM;
	121
	122	i2c_set_clientdata(client, data);
	123
f4dc811c CG	124	if (np) {
	125	if (!of_property_read_u32(np, "reference-voltage-microvolt",
	126	&data->vdd))
	127	data->vdd /= 1000;
	128	else
	129	data->vdd = MCP3021_VDD_REF_DEFAULT;
	130	} else {
	131	u32 *pdata = dev_get_platdata(&client->dev);
	132
	133	if (pdata)
	134	data->vdd = *pdata;
	135	else
	136	data->vdd = MCP3021_VDD_REF_DEFAULT;
	137	}
	138
8b662f38 SS	139	switch (id->driver_data) {
	140	case mcp3021:
	141	data->sar_shift = MCP3021_SAR_SHIFT;
	142	data->sar_mask = MCP3021_SAR_MASK;
	143	data->output_res = MCP3021_OUTPUT_RES;
8b662f38	144	break;
592758b1 SS	145
	146	case mcp3221:
	147	data->sar_shift = MCP3221_SAR_SHIFT;
	148	data->sar_mask = MCP3221_SAR_MASK;
	149	data->output_res = MCP3221_OUTPUT_RES;
592758b1	150	break;
8b662f38 SS	151	}
8b662f38 SS	152
f4dc811c CG	153	if (data->vdd > MCP3021_VDD_REF_MAX \|\| data->vdd < MCP3021_VDD_REF_MIN)
f4dc811c CG	154	return -EINVAL;
5510e62a XX	155
	156	err = sysfs_create_file(&client->dev.kobj, &dev_attr_in0_input.attr);
	157	if (err)
79831fd4	158	return err;
5510e62a XX	159
	160	data->hwmon_dev = hwmon_device_register(&client->dev);
	161	if (IS_ERR(data->hwmon_dev)) {
	162	err = PTR_ERR(data->hwmon_dev);
	163	goto exit_remove;
	164	}
	165
	166	return 0;
	167
	168	exit_remove:
	169	sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr);
5510e62a XX	170	return err;
	171	}
	172
	173	static int mcp3021_remove(struct i2c_client *client)
	174	{
	175	struct mcp3021_data *data = i2c_get_clientdata(client);
	176
	177	hwmon_device_unregister(data->hwmon_dev);
	178	sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr);
5510e62a XX	179
	180	return 0;
	181	}
	182
	183	static const struct i2c_device_id mcp3021_id[] = {
8b662f38	184	{ "mcp3021", mcp3021 },
592758b1	185	{ "mcp3221", mcp3221 },
5510e62a XX	186	{ }
	187	};
	188	MODULE_DEVICE_TABLE(i2c, mcp3021_id);
	189
f4dc811c CG	190	#ifdef CONFIG_OF
	191	static const struct of_device_id of_mcp3021_match[] = {
	192	{ .compatible = "microchip,mcp3021", .data = (void *)mcp3021 },
	193	{ .compatible = "microchip,mcp3221", .data = (void *)mcp3221 },
	194	{ }
	195	};
	196	MODULE_DEVICE_TABLE(of, of_mcp3021_match);
	197	#endif
	198
5510e62a XX	199	static struct i2c_driver mcp3021_driver = {
	200	.driver = {
	201	.name = "mcp3021",
f4dc811c	202	.of_match_table = of_match_ptr(of_mcp3021_match),
5510e62a XX	203	},
	204	.probe = mcp3021_probe,
	205	.remove = mcp3021_remove,
	206	.id_table = mcp3021_id,
	207	};
	208
	209	module_i2c_driver(mcp3021_driver);
	210
	211	MODULE_AUTHOR("Mingkai Hu <Mingkai.hu@freescale.com>");
592758b1	212	MODULE_DESCRIPTION("Microchip MCP3021/MCP3221 driver");
5510e62a	213	MODULE_LICENSE("GPL");