xref: /openbmc/linux/drivers/iio/accel/mc3230.c (revision 7cf15f42)
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 
38 static 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 
49 static 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 
55 struct mc3230_data {
56 	struct i2c_client *client;
57 };
58 
mc3230_set_opcon(struct mc3230_data * data,int opcon)59 static 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 
mc3230_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)82 static 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 
105 static const struct iio_info mc3230_info = {
106 	.read_raw	= mc3230_read_raw,
107 };
108 
mc3230_probe(struct i2c_client * client)109 static 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 
mc3230_remove(struct i2c_client * client)153 static 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 
mc3230_suspend(struct device * dev)162 static 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 
mc3230_resume(struct device * dev)171 static 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 
180 static DEFINE_SIMPLE_DEV_PM_OPS(mc3230_pm_ops, mc3230_suspend, mc3230_resume);
181 
182 static const struct i2c_device_id mc3230_i2c_id[] = {
183 	{"mc3230", 0},
184 	{}
185 };
186 MODULE_DEVICE_TABLE(i2c, mc3230_i2c_id);
187 
188 static 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 
198 module_i2c_driver(mc3230_driver);
199 
200 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
201 MODULE_DESCRIPTION("mCube MC3230 3-Axis Accelerometer driver");
202 MODULE_LICENSE("GPL v2");
203