--- /dev/null
+/**
+ * IIO driver for the 3-axis accelerometer Domintech ARD10.
+ *
+ * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
+ * Copyright (c) 2012 Domintech Technology Co., Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/byteorder/generic.h>
+
+#define DMARD10_REG_ACTR 0x00
+#define DMARD10_REG_AFEM 0x0c
+#define DMARD10_REG_STADR 0x12
+#define DMARD10_REG_STAINT 0x1c
+#define DMARD10_REG_MISC2 0x1f
+#define DMARD10_REG_PD 0x21
+
+#define DMARD10_MODE_OFF 0x00
+#define DMARD10_MODE_STANDBY 0x02
+#define DMARD10_MODE_ACTIVE 0x06
+#define DMARD10_MODE_READ_OTP 0x12
+#define DMARD10_MODE_RESET_DATA_PATH 0x82
+
+/* AFEN set 1, ATM[2:0]=b'000 (normal), EN_Z/Y/X/T=1 */
+#define DMARD10_VALUE_AFEM_AFEN_NORMAL 0x8f
+/* ODR[3:0]=b'0111 (100Hz), CCK[3:0]=b'0100 (204.8kHZ) */
+#define DMARD10_VALUE_CKSEL_ODR_100_204 0x74
+/* INTC[6:5]=b'00 */
+#define DMARD10_VALUE_INTC 0x00
+/* TAP1/TAP2 Average 2 */
+#define DMARD10_VALUE_TAPNS_AVE_2 0x11
+
+#define DMARD10_VALUE_STADR 0x55
+#define DMARD10_VALUE_STAINT 0xaa
+#define DMARD10_VALUE_MISC2_OSCA_EN 0x08
+#define DMARD10_VALUE_PD_RST 0x52
+
+/* Offsets into the buffer read in dmard10_read_raw() */
+#define DMARD10_X_OFFSET 1
+#define DMARD10_Y_OFFSET 2
+#define DMARD10_Z_OFFSET 3
+
+/*
+ * a value of + or -128 corresponds to + or - 1G
+ * scale = 9.81 / 128 = 0.076640625
+ */
+
+static const int dmard10_nscale = 76640625;
+
+#define DMARD10_CHANNEL(reg, axis) { \
+ .type = IIO_ACCEL, \
+ .address = reg, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_##axis, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+}
+
+static const struct iio_chan_spec dmard10_channels[] = {
+ DMARD10_CHANNEL(DMARD10_X_OFFSET, X),
+ DMARD10_CHANNEL(DMARD10_Y_OFFSET, Y),
+ DMARD10_CHANNEL(DMARD10_Z_OFFSET, Z),
+};
+
+struct dmard10_data {
+ struct i2c_client *client;
+};
+
+/* Init sequence taken from the android driver */
+static int dmard10_reset(struct i2c_client *client)
+{
+ unsigned char buffer[7];
+ int ret;
+
+ /* 1. Powerdown reset */
+ ret = i2c_smbus_write_byte_data(client, DMARD10_REG_PD,
+ DMARD10_VALUE_PD_RST);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * 2. ACTR => Standby mode => Download OTP to parameter reg =>
+ * Standby mode => Reset data path => Standby mode
+ */
+ buffer[0] = DMARD10_REG_ACTR;
+ buffer[1] = DMARD10_MODE_STANDBY;
+ buffer[2] = DMARD10_MODE_READ_OTP;
+ buffer[3] = DMARD10_MODE_STANDBY;
+ buffer[4] = DMARD10_MODE_RESET_DATA_PATH;
+ buffer[5] = DMARD10_MODE_STANDBY;
+ ret = i2c_master_send(client, buffer, 6);
+ if (ret < 0)
+ return ret;
+
+ /* 3. OSCA_EN = 1, TSTO = b'000 (INT1 = normal, TEST0 = normal) */
+ ret = i2c_smbus_write_byte_data(client, DMARD10_REG_MISC2,
+ DMARD10_VALUE_MISC2_OSCA_EN);
+ if (ret < 0)
+ return ret;
+
+ /* 4. AFEN = 1 (AFE will powerdown after ADC) */
+ buffer[0] = DMARD10_REG_AFEM;
+ buffer[1] = DMARD10_VALUE_AFEM_AFEN_NORMAL;
+ buffer[2] = DMARD10_VALUE_CKSEL_ODR_100_204;
+ buffer[3] = DMARD10_VALUE_INTC;
+ buffer[4] = DMARD10_VALUE_TAPNS_AVE_2;
+ buffer[5] = 0x00; /* DLYC, no delay timing */
+ buffer[6] = 0x07; /* INTD=1 push-pull, INTA=1 active high, AUTOT=1 */
+ ret = i2c_master_send(client, buffer, 7);
+ if (ret < 0)
+ return ret;
+
+ /* 5. Activation mode */
+ ret = i2c_smbus_write_byte_data(client, DMARD10_REG_ACTR,
+ DMARD10_MODE_ACTIVE);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+/* Shutdown sequence taken from the android driver */
+static int dmard10_shutdown(struct i2c_client *client)
+{
+ unsigned char buffer[3];
+
+ buffer[0] = DMARD10_REG_ACTR;
+ buffer[1] = DMARD10_MODE_STANDBY;
+ buffer[2] = DMARD10_MODE_OFF;
+
+ return i2c_master_send(client, buffer, 3);
+}
+
+static int dmard10_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct dmard10_data *data = iio_priv(indio_dev);
+ __le16 buf[4];
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ /*
+ * Read 8 bytes starting at the REG_STADR register, trying to
+ * read the individual X, Y, Z registers will always read 0.
+ */
+ ret = i2c_smbus_read_i2c_block_data(data->client,
+ DMARD10_REG_STADR,
+ sizeof(buf), (u8 *)buf);
+ if (ret < 0)
+ return ret;
+ ret = le16_to_cpu(buf[chan->address]);
+ *val = sign_extend32(ret, 12);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = 0;
+ *val2 = dmard10_nscale;
+ return IIO_VAL_INT_PLUS_NANO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info dmard10_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = dmard10_read_raw,
+};
+
+static int dmard10_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int ret;
+ struct iio_dev *indio_dev;
+ struct dmard10_data *data;
+
+ /* These 2 registers have special POR reset values used for id */
+ ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STADR);
+ if (ret != DMARD10_VALUE_STADR)
+ return (ret < 0) ? ret : -ENODEV;
+
+ ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STAINT);
+ if (ret != DMARD10_VALUE_STAINT)
+ return (ret < 0) ? ret : -ENODEV;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev) {
+ dev_err(&client->dev, "iio allocation failed!\n");
+ return -ENOMEM;
+ }
+
+ data = iio_priv(indio_dev);
+ data->client = client;
+ i2c_set_clientdata(client, indio_dev);
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &dmard10_info;
+ indio_dev->name = "dmard10";
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = dmard10_channels;
+ indio_dev->num_channels = ARRAY_SIZE(dmard10_channels);
+
+ ret = dmard10_reset(client);
+ if (ret < 0)
+ return ret;
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "device_register failed\n");
+ dmard10_shutdown(client);
+ }
+
+ return ret;
+}
+
+static int dmard10_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+ iio_device_unregister(indio_dev);
+
+ return dmard10_shutdown(client);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int dmard10_suspend(struct device *dev)
+{
+ return dmard10_shutdown(to_i2c_client(dev));
+}
+
+static int dmard10_resume(struct device *dev)
+{
+ return dmard10_reset(to_i2c_client(dev));
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(dmard10_pm_ops, dmard10_suspend, dmard10_resume);
+
+static const struct i2c_device_id dmard10_i2c_id[] = {
+ {"dmard10", 0},
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, dmard10_i2c_id);
+
+static struct i2c_driver dmard10_driver = {
+ .driver = {
+ .name = "dmard10",
+ .pm = &dmard10_pm_ops,
+ },
+ .probe = dmard10_probe,
+ .remove = dmard10_remove,
+ .id_table = dmard10_i2c_id,
+};
+
+module_i2c_driver(dmard10_driver);
+
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
+MODULE_DESCRIPTION("Domintech ARD10 3-Axis Accelerometer driver");
+MODULE_LICENSE("GPL v2");
projects / linux-beck.git / commitdiff