iio/accel/dmard10.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * IIO driver for the 3-axis accelerometer Domintech ARD10.
0004  *
0005  * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
0006  * Copyright (c) 2012 Domintech Technology Co., Ltd
0007  */
0008
0009 #include <linux/module.h>
0010 #include <linux/i2c.h>
0011 #include <linux/iio/iio.h>
0012 #include <linux/iio/sysfs.h>
0013 #include <linux/byteorder/generic.h>
0014
0015 #define DMARD10_REG_ACTR            0x00
0016 #define DMARD10_REG_AFEM            0x0c
0017 #define DMARD10_REG_STADR           0x12
0018 #define DMARD10_REG_STAINT          0x1c
0019 #define DMARD10_REG_MISC2           0x1f
0020 #define DMARD10_REG_PD              0x21
0021
0022 #define DMARD10_MODE_OFF            0x00
0023 #define DMARD10_MODE_STANDBY            0x02
0024 #define DMARD10_MODE_ACTIVE         0x06
0025 #define DMARD10_MODE_READ_OTP           0x12
0026 #define DMARD10_MODE_RESET_DATA_PATH        0x82
0027
0028 /* AFEN set 1, ATM[2:0]=b'000 (normal), EN_Z/Y/X/T=1 */
0029 #define DMARD10_VALUE_AFEM_AFEN_NORMAL      0x8f
0030 /* ODR[3:0]=b'0111 (100Hz), CCK[3:0]=b'0100 (204.8kHZ) */
0031 #define DMARD10_VALUE_CKSEL_ODR_100_204     0x74
0032 /* INTC[6:5]=b'00 */
0033 #define DMARD10_VALUE_INTC          0x00
0034 /* TAP1/TAP2 Average 2 */
0035 #define DMARD10_VALUE_TAPNS_AVE_2       0x11
0036
0037 #define DMARD10_VALUE_STADR         0x55
0038 #define DMARD10_VALUE_STAINT            0xaa
0039 #define DMARD10_VALUE_MISC2_OSCA_EN     0x08
0040 #define DMARD10_VALUE_PD_RST            0x52
0041
0042 /* Offsets into the buffer read in dmard10_read_raw() */
0043 #define DMARD10_X_OFFSET            1
0044 #define DMARD10_Y_OFFSET            2
0045 #define DMARD10_Z_OFFSET            3
0046
0047 /*
0048  * a value of + or -128 corresponds to + or - 1G
0049  * scale = 9.81 / 128 = 0.076640625
0050  */
0051
0052 static const int dmard10_nscale = 76640625;
0053
0054 #define DMARD10_CHANNEL(reg, axis) {    \
0055     .type = IIO_ACCEL,  \
0056     .address = reg, \
0057     .modified = 1,  \
0058     .channel2 = IIO_MOD_##axis, \
0059     .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
0060     .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
0061 }
0062
0063 static const struct iio_chan_spec dmard10_channels[] = {
0064     DMARD10_CHANNEL(DMARD10_X_OFFSET, X),
0065     DMARD10_CHANNEL(DMARD10_Y_OFFSET, Y),
0066     DMARD10_CHANNEL(DMARD10_Z_OFFSET, Z),
0067 };
0068
0069 struct dmard10_data {
0070     struct i2c_client *client;
0071 };
0072
0073 /* Init sequence taken from the android driver */
0074 static int dmard10_reset(struct i2c_client *client)
0075 {
0076     unsigned char buffer[7];
0077     int ret;
0078
0079     /* 1. Powerdown reset */
0080     ret = i2c_smbus_write_byte_data(client, DMARD10_REG_PD,
0081                         DMARD10_VALUE_PD_RST);
0082     if (ret < 0)
0083         return ret;
0084
0085     /*
0086      * 2. ACTR => Standby mode => Download OTP to parameter reg =>
0087      *    Standby mode => Reset data path => Standby mode
0088      */
0089     buffer[0] = DMARD10_REG_ACTR;
0090     buffer[1] = DMARD10_MODE_STANDBY;
0091     buffer[2] = DMARD10_MODE_READ_OTP;
0092     buffer[3] = DMARD10_MODE_STANDBY;
0093     buffer[4] = DMARD10_MODE_RESET_DATA_PATH;
0094     buffer[5] = DMARD10_MODE_STANDBY;
0095     ret = i2c_master_send(client, buffer, 6);
0096     if (ret < 0)
0097         return ret;
0098
0099     /* 3. OSCA_EN = 1, TSTO = b'000 (INT1 = normal, TEST0 = normal) */
0100     ret = i2c_smbus_write_byte_data(client, DMARD10_REG_MISC2,
0101                         DMARD10_VALUE_MISC2_OSCA_EN);
0102     if (ret < 0)
0103         return ret;
0104
0105     /* 4. AFEN = 1 (AFE will powerdown after ADC) */
0106     buffer[0] = DMARD10_REG_AFEM;
0107     buffer[1] = DMARD10_VALUE_AFEM_AFEN_NORMAL;
0108     buffer[2] = DMARD10_VALUE_CKSEL_ODR_100_204;
0109     buffer[3] = DMARD10_VALUE_INTC;
0110     buffer[4] = DMARD10_VALUE_TAPNS_AVE_2;
0111     buffer[5] = 0x00; /* DLYC, no delay timing */
0112     buffer[6] = 0x07; /* INTD=1 push-pull, INTA=1 active high, AUTOT=1 */
0113     ret = i2c_master_send(client, buffer, 7);
0114     if (ret < 0)
0115         return ret;
0116
0117     /* 5. Activation mode */
0118     ret = i2c_smbus_write_byte_data(client, DMARD10_REG_ACTR,
0119                         DMARD10_MODE_ACTIVE);
0120     if (ret < 0)
0121         return ret;
0122
0123     return 0;
0124 }
0125
0126 /* Shutdown sequence taken from the android driver */
0127 static int dmard10_shutdown(struct i2c_client *client)
0128 {
0129     unsigned char buffer[3];
0130
0131     buffer[0] = DMARD10_REG_ACTR;
0132     buffer[1] = DMARD10_MODE_STANDBY;
0133     buffer[2] = DMARD10_MODE_OFF;
0134
0135     return i2c_master_send(client, buffer, 3);
0136 }
0137
0138 static int dmard10_read_raw(struct iio_dev *indio_dev,
0139                 struct iio_chan_spec const *chan,
0140                 int *val, int *val2, long mask)
0141 {
0142     struct dmard10_data *data = iio_priv(indio_dev);
0143     __le16 buf[4];
0144     int ret;
0145
0146     switch (mask) {
0147     case IIO_CHAN_INFO_RAW:
0148         /*
0149          * Read 8 bytes starting at the REG_STADR register, trying to
0150          * read the individual X, Y, Z registers will always read 0.
0151          */
0152         ret = i2c_smbus_read_i2c_block_data(data->client,
0153                             DMARD10_REG_STADR,
0154                             sizeof(buf), (u8 *)buf);
0155         if (ret < 0)
0156             return ret;
0157         ret = le16_to_cpu(buf[chan->address]);
0158         *val = sign_extend32(ret, 12);
0159         return IIO_VAL_INT;
0160     case IIO_CHAN_INFO_SCALE:
0161         *val = 0;
0162         *val2 = dmard10_nscale;
0163         return IIO_VAL_INT_PLUS_NANO;
0164     default:
0165         return -EINVAL;
0166     }
0167 }
0168
0169 static const struct iio_info dmard10_info = {
0170     .read_raw   = dmard10_read_raw,
0171 };
0172
0173 static void dmard10_shutdown_cleanup(void *client)
0174 {
0175     dmard10_shutdown(client);
0176 }
0177
0178 static int dmard10_probe(struct i2c_client *client,
0179             const struct i2c_device_id *id)
0180 {
0181     int ret;
0182     struct iio_dev *indio_dev;
0183     struct dmard10_data *data;
0184
0185     /* These 2 registers have special POR reset values used for id */
0186     ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STADR);
0187     if (ret != DMARD10_VALUE_STADR)
0188         return (ret < 0) ? ret : -ENODEV;
0189
0190     ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STAINT);
0191     if (ret != DMARD10_VALUE_STAINT)
0192         return (ret < 0) ? ret : -ENODEV;
0193
0194     indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
0195     if (!indio_dev) {
0196         dev_err(&client->dev, "iio allocation failed!\n");
0197         return -ENOMEM;
0198     }
0199
0200     data = iio_priv(indio_dev);
0201     data->client = client;
0202
0203     indio_dev->info = &dmard10_info;
0204     indio_dev->name = "dmard10";
0205     indio_dev->modes = INDIO_DIRECT_MODE;
0206     indio_dev->channels = dmard10_channels;
0207     indio_dev->num_channels = ARRAY_SIZE(dmard10_channels);
0208
0209     ret = dmard10_reset(client);
0210     if (ret < 0)
0211         return ret;
0212
0213     ret = devm_add_action_or_reset(&client->dev, dmard10_shutdown_cleanup,
0214                        client);
0215     if (ret)
0216         return ret;
0217
0218     return devm_iio_device_register(&client->dev, indio_dev);
0219 }
0220
0221 static int dmard10_suspend(struct device *dev)
0222 {
0223     return dmard10_shutdown(to_i2c_client(dev));
0224 }
0225
0226 static int dmard10_resume(struct device *dev)
0227 {
0228     return dmard10_reset(to_i2c_client(dev));
0229 }
0230
0231 static DEFINE_SIMPLE_DEV_PM_OPS(dmard10_pm_ops, dmard10_suspend,
0232                 dmard10_resume);
0233
0234 static const struct i2c_device_id dmard10_i2c_id[] = {
0235     {"dmard10", 0},
0236     {}
0237 };
0238 MODULE_DEVICE_TABLE(i2c, dmard10_i2c_id);
0239
0240 static struct i2c_driver dmard10_driver = {
0241     .driver = {
0242         .name = "dmard10",
0243         .pm = pm_sleep_ptr(&dmard10_pm_ops),
0244     },
0245     .probe      = dmard10_probe,
0246     .id_table   = dmard10_i2c_id,
0247 };
0248
0249 module_i2c_driver(dmard10_driver);
0250
0251 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
0252 MODULE_DESCRIPTION("Domintech ARD10 3-Axis Accelerometer driver");
0253 MODULE_LICENSE("GPL v2");