On Fri, 15 May 2015, Tiberiu Breana wrote: > Minimal implementation of an IIO driver for the Sensortek > STK8BA50 3-axis accelerometer. Datasheet: > http://szgsensor.com/uploads/soft/141229/STK8BA50%D2%E5%BC%CE.pdf comments below > Includes: > - ACPI support; > - read_raw for x,y,z axes; > - reading and setting the scale (range) parameter. > - power management > > Signed-off-by: Tiberiu Breana <tiberiu.a.breana@xxxxxxxxx> > --- > drivers/iio/accel/Kconfig | 11 ++ > drivers/iio/accel/Makefile | 2 + > drivers/iio/accel/stk8ba50.c | 312 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 325 insertions(+) > create mode 100644 drivers/iio/accel/stk8ba50.c > > diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig > index 7c9a9a9..059e119 100644 > --- a/drivers/iio/accel/Kconfig > +++ b/drivers/iio/accel/Kconfig > @@ -136,4 +136,15 @@ config MMA9553 > > To compile this driver as a module, choose M here: the module > will be called mma9553. > + > +config STK8BA50 > + tristate "Sensortek STK8BA50 3-Axis Accelerometer Driver" > + depends on I2C > + help > + Say yes here to get support for the Sensortek STK8BA50 3-axis > + accelerometer. > + > + Choosing M will build the driver as a module. If so, the module > + will be called stk8ba50. > + > endmenu > diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile > index 99d89e4..339d80c 100644 > --- a/drivers/iio/accel/Makefile > +++ b/drivers/iio/accel/Makefile > @@ -14,6 +14,8 @@ obj-$(CONFIG_MMA9551_CORE) += mma9551_core.o > obj-$(CONFIG_MMA9551) += mma9551.o > obj-$(CONFIG_MMA9553) += mma9553.o > > +obj-$(CONFIG_STK8BA50) += stk8ba50.o > + > obj-$(CONFIG_IIO_SSP_SENSORS_COMMONS) += ssp_accel_sensor.o > > obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o > diff --git a/drivers/iio/accel/stk8ba50.c b/drivers/iio/accel/stk8ba50.c > new file mode 100644 > index 0000000..663c0fd > --- /dev/null > +++ b/drivers/iio/accel/stk8ba50.c > @@ -0,0 +1,312 @@ > +/** > + * Sensortek STK8BA50 3-Axis Accelerometer > + * > + * Copyright (c) 2015, Intel Corporation. > + * > + * This file is subject to the terms and conditions of version 2 of > + * the GNU General Public License. See the file COPYING in the main > + * directory of this archive for more details. > + * > + * STK8BA50 7-bit I2C address: 0x18. > + */ > + > +#include <linux/acpi.h> > +#include <linux/i2c.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > + > +#define STK8BA50_REG_XOUT 0x02 > +#define STK8BA50_REG_YOUT 0x04 > +#define STK8BA50_REG_ZOUT 0x06 > +#define STK8BA50_REG_RANGE 0x0F > +#define STK8BA50_REG_POWMODE 0x11 > +#define STK8BA50_REG_SWRST 0x14 > + > +#define STK8BA50_MODE_NORMAL 0 > +#define STK8BA50_MODE_SUSPEND 1 > +#define STK8BA50_MODE_MASK 0x80 > +#define STK8BA50_MODE_SHIFT 7 > +#define STK8BA50_LSB_MASK 0xC000 > +#define STK8BA50_MSB_MASK 0x00FF > +#define STK8BA50_LSB_SHIFT 14 > +#define STK8BA50_MSB_SHIFT 2 > +#define STK8BA50_RESET_CMD 0xB6 > + > +#define STK8BA50_DRIVER_NAME "stk8ba50" > + > +#define STK8BA50_SCALE_AVAIL "0.0384 0.0767 0.1534 0.3069" > + > +/* > + * The accelerometer has four measurement ranges: > + * +/-2g; +/-4g; +/-8g; +/-16g > + * > + * Acceleration values are 10-bit, 2's complement. > + * Scales are calculated as following: > + * > + * scale1 = (2 + 2) * 9.81 / (2^10 - 1) = 0.0384 > + * scale2 = (4 + 4) * 9.81 / (2^10 - 1) = 0.0767 > + * etc. > + * > + * Scales are stored in this format: > + * { <register value>, <scale value> } > + * Locally the range is stored as a table index. > + */ > +static const int stk8ba50_scale_table[][2] = { > + {3, 38400}, {5, 76700}, {8, 153400}, {12, 306900} > +}; > + > +struct stk8ba50_data { > + struct i2c_client *client; > + struct mutex lock; > + int range; > +}; > + > +#define STK8BA50_ACCEL_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 stk8ba50_channels[] = { > + STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_XOUT, X), > + STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_YOUT, Y), > + STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_ZOUT, Z), > +}; > + > +static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL); > + > +static struct attribute *stk8ba50_attributes[] = { > + &iio_const_attr_in_accel_scale_available.dev_attr.attr, > + NULL, > +}; > + > +static const struct attribute_group stk8ba50_attribute_group = { > + .attrs = stk8ba50_attributes > +}; > + > +static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg) > +{ > + int ret; > + u8 lsb; > + u8 msb; > + struct i2c_client *client = data->client; > + > + ret = i2c_smbus_read_word_swapped(client, reg); > + if (ret < 0) { > + dev_err(&client->dev, "register read failed\n"); > + return ret; > + } the chip stores XOUT in little-endian order, i.e. XOUT1 has least significant bits and XOUT2 has the most significant bits -- hence i2c_smbus_read_word_data() should be used ret will contain the 10 data bits in CPU endianess, but shifted left by 6 bits so I suggest: ret = i2c_smbus_read_word_data(client, reg); if (ret < 0) { dev_err(&client->dev, "register read failed\n"); // this this msg really necessary? return ret; } #define OUT_SHIFT 6 return sign_extend32(ret >> OUT_SHIFT, 9); > + > + lsb = (ret & STK8BA50_LSB_MASK) >> STK8BA50_LSB_SHIFT; > + msb = ret & STK8BA50_MSB_MASK; > + ret = (msb << STK8BA50_MSB_SHIFT) | lsb; > + > + return sign_extend32(ret, 9); > +} > + > +static int stk8ba50_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct stk8ba50_data *data = iio_priv(indio_dev); > + > + if (chan->type != IIO_ACCEL) > + return -EINVAL; this check is not needed I think; _write_raw() doesn't check either > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + mutex_lock(&data->lock); > + *val = stk8ba50_read_accel(data, chan->address); > + mutex_unlock(&data->lock); > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + *val = 0; > + *val2 = stk8ba50_scale_table[data->range][1]; > + return IIO_VAL_INT_PLUS_MICRO; > + } > + > + return -EINVAL; > +} > + > +static int stk8ba50_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + int ret; > + int i; > + int index = -1; > + struct stk8ba50_data *data = iio_priv(indio_dev); > + > + switch (mask) { > + case IIO_CHAN_INFO_SCALE: > + if (val != 0) > + return -EINVAL; > + > + for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++) > + if (val2 == stk8ba50_scale_table[i][1]) { > + index = i; > + break; > + } > + if (index < 0) > + return -EINVAL; > + > + ret = i2c_smbus_write_byte_data(data->client, > + STK8BA50_REG_RANGE, > + stk8ba50_scale_table[index][0]); > + if (ret < 0) > + dev_err(&data->client->dev, > + "failed to set measurement range\n"); > + else > + data->range = index; > + > + return ret; > + } > + > + return -EINVAL; > +} > + > +static const struct iio_info stk8ba50_info = { > + .driver_module = THIS_MODULE, > + .read_raw = stk8ba50_read_raw, > + .write_raw = stk8ba50_write_raw, > + .attrs = &stk8ba50_attribute_group, > +}; > + > +static int stk8ba50_set_mode(struct stk8ba50_data *data, u8 mode) > +{ > + int ret; > + u8 masked_reg; > + struct i2c_client *client = data->client; > + > + if (mode > 1) how about bool mode? or bool on? and rename to set_power()? > + return -EINVAL; > + > + ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE); > + if (ret < 0) > + goto exit_err; > + > + masked_reg = ret & (~STK8BA50_MODE_MASK); > + masked_reg |= mode >> STK8BA50_MODE_SHIFT; this should be << STK8BA50_MODE_SHIFT?! how about: #define STK8BA50_MODE_POWERBIT BIT(7) if (mode) masked_reg = ret | STK8BA50_MODE_POWERBIT else masked_reg = ret & (~STK8BA50_MODE_POWERBIT) > + > + ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE, > + masked_reg); > + if (ret < 0) > + goto exit_err; > + > + return ret; > + > +exit_err: > + dev_err(&client->dev, "failed to change sensor mode\n"); > + return ret; > +} > + > +static int stk8ba50_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + int ret; > + struct iio_dev *indio_dev; > + struct stk8ba50_data *data; > + > + 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); > + mutex_init(&data->lock); > + > + indio_dev->dev.parent = &client->dev; > + indio_dev->info = &stk8ba50_info; > + indio_dev->name = STK8BA50_DRIVER_NAME; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = stk8ba50_channels; > + indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels); > + > + /* Reset all registers on startup */ > + ret = i2c_smbus_write_byte_data(client, > + STK8BA50_REG_SWRST, STK8BA50_RESET_CMD); > + if (ret < 0) { > + dev_err(&client->dev, "failed to reset sensor\n"); > + return ret; > + } > + > + ret = iio_device_register(indio_dev); > + if (ret < 0) { > + dev_err(&client->dev, "device_register failed\n"); > + stk8ba50_set_mode(data, STK8BA50_MODE_SUSPEND); > + } > + > + return ret; > +} > + > +static int stk8ba50_remove(struct i2c_client *client) > +{ > + struct iio_dev *indio_dev = i2c_get_clientdata(client); > + > + iio_device_unregister(indio_dev); > + > + return stk8ba50_set_mode(iio_priv(indio_dev), STK8BA50_MODE_SUSPEND); > +} > + > +#ifdef CONFIG_PM_SLEEP > +static int stk8ba50_suspend(struct device *dev) > +{ > + struct stk8ba50_data *data; > + > + data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); > + > + return stk8ba50_set_mode(data, STK8BA50_MODE_SUSPEND); > +} > + > +static int stk8ba50_resume(struct device *dev) > +{ > + struct stk8ba50_data *data; > + > + data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); > + > + return stk8ba50_set_mode(data, STK8BA50_MODE_NORMAL); > +} > + > +static SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, stk8ba50_resume); > + > +#define STK8BA50_PM_OPS (&stk8ba50_pm_ops) > +#else > +#define STK8BA50_PM_OPS NULL > +#endif > + > +static const struct i2c_device_id stk8ba50_i2c_id[] = { > + {"STK8BA50", 0}, > + {} > +}; > + > +static const struct acpi_device_id stk8ba50_acpi_id[] = { > + {"STK8BA50", 0}, > + {} > +}; > + > +MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id); > + > +static struct i2c_driver stk8ba50_driver = { > + .driver = { > + .name = "stk8ba50", > + .pm = STK8BA50_PM_OPS, > + .acpi_match_table = ACPI_PTR(stk8ba50_acpi_id), > + }, > + .probe = stk8ba50_probe, > + .remove = stk8ba50_remove, > + .id_table = stk8ba50_i2c_id, > +}; > + > +module_i2c_driver(stk8ba50_driver); > + > +MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@xxxxxxxxx>"); > +MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver"); > +MODULE_LICENSE("GPL v2"); > -- Peter Meerwald +43-664-2444418 (mobile) -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
