da280.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * IIO driver for the MiraMEMS DA217 and DA280 3-axis accelerometer and
  4 * IIO driver for the MiraMEMS DA226 2-axis accelerometer
  5 *
  6 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
  7 */
  8
  9#include <linux/module.h>
 10#include <linux/i2c.h>
 11#include <linux/acpi.h>
 12#include <linux/iio/iio.h>
 13#include <linux/iio/sysfs.h>
 14#include <linux/byteorder/generic.h>
 15
 16#define DA280_REG_CHIP_ID		0x01
 17#define DA280_REG_ACC_X_LSB		0x02
 18#define DA280_REG_ACC_Y_LSB		0x04
 19#define DA280_REG_ACC_Z_LSB		0x06
 20#define DA280_REG_MODE_BW		0x11
 21
 22#define DA280_CHIP_ID			0x13
 23#define DA280_MODE_ENABLE		0x1e
 24#define DA280_MODE_DISABLE		0x9e
 25
 26/*
 27 * a value of + or -4096 corresponds to + or - 1G
 28 * scale = 9.81 / 4096 = 0.002395019
 29 */
 30
 31static const int da280_nscale = 2395019;
 32
 33#define DA280_CHANNEL(reg, axis) {	\
 34	.type = IIO_ACCEL,	\
 35	.address = reg,	\
 36	.modified = 1,	\
 37	.channel2 = IIO_MOD_##axis,	\
 38	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
 39	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
 40}
 41
 42static const struct iio_chan_spec da280_channels[] = {
 43	DA280_CHANNEL(DA280_REG_ACC_X_LSB, X),
 44	DA280_CHANNEL(DA280_REG_ACC_Y_LSB, Y),
 45	DA280_CHANNEL(DA280_REG_ACC_Z_LSB, Z),
 46};
 47
 48struct da280_match_data {
 49	const char *name;
 50	int num_channels;
 51};
 52
 53struct da280_data {
 54	struct i2c_client *client;
 55};
 56
 57static int da280_enable(struct i2c_client *client, bool enable)
 58{
 59	u8 data = enable ? DA280_MODE_ENABLE : DA280_MODE_DISABLE;
 60
 61	return i2c_smbus_write_byte_data(client, DA280_REG_MODE_BW, data);
 62}
 63
 64static int da280_read_raw(struct iio_dev *indio_dev,
 65				struct iio_chan_spec const *chan,
 66				int *val, int *val2, long mask)
 67{
 68	struct da280_data *data = iio_priv(indio_dev);
 69	int ret;
 70
 71	switch (mask) {
 72	case IIO_CHAN_INFO_RAW:
 73		ret = i2c_smbus_read_word_data(data->client, chan->address);
 74		if (ret < 0)
 75			return ret;
 76		/*
 77		 * Values are 14 bits, stored as 16 bits with the 2
 78		 * least significant bits always 0.
 79		 */
 80		*val = (short)ret >> 2;
 81		return IIO_VAL_INT;
 82	case IIO_CHAN_INFO_SCALE:
 83		*val = 0;
 84		*val2 = da280_nscale;
 85		return IIO_VAL_INT_PLUS_NANO;
 86	default:
 87		return -EINVAL;
 88	}
 89}
 90
 91static const struct iio_info da280_info = {
 92	.read_raw	= da280_read_raw,
 93};
 94
 95static void da280_disable(void *client)
 96{
 97	da280_enable(client, false);
 98}
 99
100static int da280_probe(struct i2c_client *client)
101{
102	const struct da280_match_data *match_data;
103	struct iio_dev *indio_dev;
104	struct da280_data *data;
105	int ret;
106
107	ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID);
108	if (ret != DA280_CHIP_ID)
109		return (ret < 0) ? ret : -ENODEV;
110
111	match_data = i2c_get_match_data(client);
112	if (!match_data) {
113		dev_err(&client->dev, "Error match-data not set\n");
114		return -EINVAL;
115	}
116
117	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
118	if (!indio_dev)
119		return -ENOMEM;
120
121	data = iio_priv(indio_dev);
122	data->client = client;
123
124	indio_dev->info = &da280_info;
125	indio_dev->modes = INDIO_DIRECT_MODE;
126	indio_dev->channels = da280_channels;
127	indio_dev->num_channels = match_data->num_channels;
128	indio_dev->name = match_data->name;
129
130	ret = da280_enable(client, true);
131	if (ret < 0)
132		return ret;
133
134	ret = devm_add_action_or_reset(&client->dev, da280_disable, client);
135	if (ret)
136		return ret;
137
138	return devm_iio_device_register(&client->dev, indio_dev);
139}
140
141static int da280_suspend(struct device *dev)
142{
143	return da280_enable(to_i2c_client(dev), false);
144}
145
146static int da280_resume(struct device *dev)
147{
148	return da280_enable(to_i2c_client(dev), true);
149}
150
151static DEFINE_SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume);
152
153static const struct da280_match_data da217_match_data = { "da217", 3 };
154static const struct da280_match_data da226_match_data = { "da226", 2 };
155static const struct da280_match_data da280_match_data = { "da280", 3 };
156
157static const struct acpi_device_id da280_acpi_match[] = {
158	{ "NSA2513", (kernel_ulong_t)&da217_match_data },
159	{ "MIRAACC", (kernel_ulong_t)&da280_match_data },
160	{ }
161};
162MODULE_DEVICE_TABLE(acpi, da280_acpi_match);
163
164static const struct i2c_device_id da280_i2c_id[] = {
165	{ "da217", (kernel_ulong_t)&da217_match_data },
166	{ "da226", (kernel_ulong_t)&da226_match_data },
167	{ "da280", (kernel_ulong_t)&da280_match_data },
168	{ }
169};
170MODULE_DEVICE_TABLE(i2c, da280_i2c_id);
171
172static struct i2c_driver da280_driver = {
173	.driver = {
174		.name = "da280",
175		.acpi_match_table = da280_acpi_match,
176		.pm = pm_sleep_ptr(&da280_pm_ops),
177	},
178	.probe		= da280_probe,
179	.id_table	= da280_i2c_id,
180};
181
182module_i2c_driver(da280_driver);
183
184MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
185MODULE_DESCRIPTION("MiraMEMS DA280 3-Axis Accelerometer driver");
186MODULE_LICENSE("GPL v2");