1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * mCube MC3230 3-Axis Accelerometer
  4 *
  5 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
  6 *
  7 * IIO driver for mCube MC3230; 7-bit I2C address: 0x4c.
  8 */
  9
 10#include <linux/i2c.h>
 11#include <linux/module.h>
 12#include <linux/iio/iio.h>
 13#include <linux/iio/sysfs.h>
 14
 15#define MC3230_REG_XOUT			0x00
 16#define MC3230_REG_YOUT			0x01
 17#define MC3230_REG_ZOUT			0x02
 18
 19#define MC3230_REG_MODE			0x07
 20#define MC3230_MODE_OPCON_MASK		0x03
 21#define MC3230_MODE_OPCON_WAKE		0x01
 22#define MC3230_MODE_OPCON_STANDBY	0x03
 23
 24#define MC3230_REG_CHIP_ID		0x18
 25#define MC3230_CHIP_ID			0x01
 26
 27#define MC3230_REG_PRODUCT_CODE		0x3b
 28#define MC3230_PRODUCT_CODE		0x19
 29
 30/*
 31 * The accelerometer has one measurement range:
 32 *
 33 * -1.5g - +1.5g (8-bit, signed)
 34 *
 35 * scale = (1.5 + 1.5) * 9.81 / (2^8 - 1)	= 0.115411765
 36 */
 37
 38static const int mc3230_nscale = 115411765;
 39
 40#define MC3230_CHANNEL(reg, axis) {	\
 41	.type = IIO_ACCEL,	\
 42	.address = reg,	\
 43	.modified = 1,	\
 44	.channel2 = IIO_MOD_##axis,	\
 45	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
 46	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
 47}
 48
 49static const struct iio_chan_spec mc3230_channels[] = {
 50	MC3230_CHANNEL(MC3230_REG_XOUT, X),
 51	MC3230_CHANNEL(MC3230_REG_YOUT, Y),
 52	MC3230_CHANNEL(MC3230_REG_ZOUT, Z),
 53};
 54
 55struct mc3230_data {
 56	struct i2c_client *client;
 57};
 58
 59static int mc3230_set_opcon(struct mc3230_data *data, int opcon)
 60{
 61	int ret;
 62	struct i2c_client *client = data->client;
 63
 64	ret = i2c_smbus_read_byte_data(client, MC3230_REG_MODE);
 65	if (ret < 0) {
 66		dev_err(&client->dev, "failed to read mode reg: %d\n", ret);
 67		return ret;
 68	}
 69
 70	ret &= ~MC3230_MODE_OPCON_MASK;
 71	ret |= opcon;
 72
 73	ret = i2c_smbus_write_byte_data(client, MC3230_REG_MODE, ret);
 74	if (ret < 0) {
 75		dev_err(&client->dev, "failed to write mode reg: %d\n", ret);
 76		return ret;
 77	}
 78
 79	return 0;
 80}
 81
 82static int mc3230_read_raw(struct iio_dev *indio_dev,
 83				struct iio_chan_spec const *chan,
 84				int *val, int *val2, long mask)
 85{
 86	struct mc3230_data *data = iio_priv(indio_dev);
 87	int ret;
 88
 89	switch (mask) {
 90	case IIO_CHAN_INFO_RAW:
 91		ret = i2c_smbus_read_byte_data(data->client, chan->address);
 92		if (ret < 0)
 93			return ret;
 94		*val = sign_extend32(ret, 7);
 95		return IIO_VAL_INT;
 96	case IIO_CHAN_INFO_SCALE:
 97		*val = 0;
 98		*val2 = mc3230_nscale;
 99		return IIO_VAL_INT_PLUS_NANO;
100	default:
101		return -EINVAL;
102	}
103}
104
105static const struct iio_info mc3230_info = {
106	.read_raw	= mc3230_read_raw,
107};
108
109static int mc3230_probe(struct i2c_client *client)
110{
111	int ret;
112	struct iio_dev *indio_dev;
113	struct mc3230_data *data;
114
115	/* First check chip-id and product-id */
116	ret = i2c_smbus_read_byte_data(client, MC3230_REG_CHIP_ID);
117	if (ret != MC3230_CHIP_ID)
118		return (ret < 0) ? ret : -ENODEV;
119
120	ret = i2c_smbus_read_byte_data(client, MC3230_REG_PRODUCT_CODE);
121	if (ret != MC3230_PRODUCT_CODE)
122		return (ret < 0) ? ret : -ENODEV;
123
124	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
125	if (!indio_dev) {
126		dev_err(&client->dev, "iio allocation failed!\n");
127		return -ENOMEM;
128	}
129
130	data = iio_priv(indio_dev);
131	data->client = client;
132	i2c_set_clientdata(client, indio_dev);
133
134	indio_dev->info = &mc3230_info;
135	indio_dev->name = "mc3230";
136	indio_dev->modes = INDIO_DIRECT_MODE;
137	indio_dev->channels = mc3230_channels;
138	indio_dev->num_channels = ARRAY_SIZE(mc3230_channels);
139
140	ret = mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
141	if (ret < 0)
142		return ret;
143
144	ret = iio_device_register(indio_dev);
145	if (ret < 0) {
146		dev_err(&client->dev, "device_register failed\n");
147		mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
148	}
149
150	return ret;
151}
152
153static void mc3230_remove(struct i2c_client *client)
154{
155	struct iio_dev *indio_dev = i2c_get_clientdata(client);
156
157	iio_device_unregister(indio_dev);
158
159	mc3230_set_opcon(iio_priv(indio_dev), MC3230_MODE_OPCON_STANDBY);
160}
161
162static int mc3230_suspend(struct device *dev)
163{
164	struct mc3230_data *data;
165
166	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
167
168	return mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
169}
170
171static int mc3230_resume(struct device *dev)
172{
173	struct mc3230_data *data;
174
175	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
176
177	return mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
178}
179
180static DEFINE_SIMPLE_DEV_PM_OPS(mc3230_pm_ops, mc3230_suspend, mc3230_resume);
181
182static const struct i2c_device_id mc3230_i2c_id[] = {
183	{ "mc3230" },
184	{}
185};
186MODULE_DEVICE_TABLE(i2c, mc3230_i2c_id);
187
188static struct i2c_driver mc3230_driver = {
189	.driver = {
190		.name = "mc3230",
191		.pm = pm_sleep_ptr(&mc3230_pm_ops),
192	},
193	.probe		= mc3230_probe,
194	.remove		= mc3230_remove,
195	.id_table	= mc3230_i2c_id,
196};
197
198module_i2c_driver(mc3230_driver);
199
200MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
201MODULE_DESCRIPTION("mCube MC3230 3-Axis Accelerometer driver");
202MODULE_LICENSE("GPL v2");