Thanks for the reviews. The accelerometer has 3 measurement ranges: -1.5g - +1.5g (6 bit, signed) -6g - +6g (8 bit, signed) -16g - +16g (8 bit, signed) scale1 = 1.5 * 9.81 / 31 ~= 0.4747 scale2 = 6 * 9.81 / 127 ~= 0.4634 scale3 = 16 * 9.81 / 127 ~= 1.2359 Thus the resulting, non-monotonic scales. I'll upload v2 with the rest of the suggested changes. Regards, Tiberiu ________________________________________ From: linux-iio-owner@xxxxxxxxxxxxxxx [linux-iio-owner@xxxxxxxxxxxxxxx] on behalf of Jonathan Cameron [jic23@xxxxxxxxxxxxxxxxxxxxx] Sent: Tuesday, May 05, 2015 4:43 PM To: Breana, Tiberiu A; linux-iio@xxxxxxxxxxxxxxx Cc: Jonathan Cameron Subject: Re: [PATCH] iio: accel: Add support for Sensortek STK8312 On 5 May 2015 14:20:38 GMT+01:00, Tiberiu Breana <tiberiu.a.breana@xxxxxxxxx> wrote: >Minimal implementation of an IIO driver for the Sensortek >STK8312 3-axis accelerometer. >Datasheet: >http://www.syi-group.com/uploadpic/data/201361817562681623.pdf > >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> Looks good. Will take another look when not stuck with only my phone (and a case of broken circuit boards) whilst my laptop is in the hold of the plane... >--- > drivers/iio/accel/Kconfig | 11 ++ > drivers/iio/accel/Makefile | 2 + >drivers/iio/accel/stk8312.c | 375 >++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 388 insertions(+) > create mode 100644 drivers/iio/accel/stk8312.c > >diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig >index 7c9a9a9..8bd8ccb 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 STK8312 >+ tristate "Sensortek STK8312 3-Axis Accelerometer Driver" >+ depends on I2C >+ help >+ Say yes here to get support for the Sensortek STK8312 3-axis >+ accelerometer. >+ >+ Choosing M will build the driver as a module. If so, the module >+ will be called stk8312. >+ > endmenu >diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile >index 99d89e4..8b327c1 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_STK8312) += stk8312.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/stk8312.c b/drivers/iio/accel/stk8312.c >new file mode 100644 >index 0000000..ff27e6b >--- /dev/null >+++ b/drivers/iio/accel/stk8312.c >@@ -0,0 +1,375 @@ >+/** >+ * Sensortek STK8312 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. >+ * >+ * IIO driver for STK8312; 7-bit I2C address: 0x3D. >+ */ >+ >+#include <linux/acpi.h> >+#include <linux/i2c.h> >+#include <linux/kernel.h> >+#include <linux/module.h> >+#include <linux/delay.h> >+#include <linux/iio/iio.h> >+#include <linux/iio/sysfs.h> >+ >+#define STK8312_REG_XOUT 0x00 >+#define STK8312_REG_YOUT 0x01 >+#define STK8312_REG_ZOUT 0x02 >+#define STK8312_REG_MODE 0x07 >+#define STK8312_REG_STH 0x13 >+#define STK8312_REG_RESET 0x20 >+ >+#define STK8312_MODE_ACTIVE 1 >+#define STK8312_MODE_STANDBY 0 >+#define STK8312_MODE_MASK 0x01 >+#define STK8312_RNG_MASK 0xC0 >+#define STK8312_ALERT_MASK 0x40 >+#define STK8312_DATA6_MASK 0x3F >+#define STK8312_RNG_SHIFT 6 >+#define STK8312_READ_RETRIES 16 >+ >+#define STK8312_DRIVER_NAME "stk8312" >+ >+#define STK8312_SCALE_AVAIL "0.4747 0.4632 1.2354" >+ >+static const int stk8312_scale_table[][2] = { >+ {0, 474700}, {0, 463200}, {1, 235400} >+}; >+ >+#define STK8312_ACCEL_CHANNEL(axis) { \ >+ .type = IIO_ACCEL, \ >+ .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 stk8312_channels[] = { >+ STK8312_ACCEL_CHANNEL(X), >+ STK8312_ACCEL_CHANNEL(Y), >+ STK8312_ACCEL_CHANNEL(Z), >+}; >+ >+struct stk8312_data { >+ struct i2c_client *client; >+ struct mutex lock; >+ int range; >+ u8 mode; >+}; >+ >+static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL); >+ >+static struct attribute *stk8312_attributes[] = { >+ &iio_const_attr_in_accel_scale_available.dev_attr.attr, >+ NULL, >+}; >+ >+static const struct attribute_group stk8312_attribute_group = { >+ .attrs = stk8312_attributes >+}; >+ >+static int stk8312_set_mode(struct stk8312_data *data, u8 mode) >+{ >+ int ret; >+ u8 masked_reg; >+ struct i2c_client *client = data->client; >+ >+ if (mode > 1) >+ return -EINVAL; >+ else if (mode == data->mode) >+ return 0; >+ >+ ret = i2c_smbus_read_byte_data(client, STK8312_REG_MODE); >+ if (ret < 0) { >+ dev_err(&client->dev, "register read failed\n"); >+ return ret; >+ } >+ masked_reg = ret & (~STK8312_MODE_MASK); >+ masked_reg |= mode; >+ >+ ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, >+ masked_reg); >+ if (ret < 0) >+ dev_err(&client->dev, "failed to change sensor mode\n"); >+ else >+ data->mode = mode; >+ >+ return ret; >+} >+ >+static int stk8312_set_range(struct stk8312_data *data, u8 range) >+{ >+ int ret; >+ int masked_reg; >+ u8 mode; >+ struct i2c_client *client = data->client; >+ >+ if (range < 0 || range > 2) >+ return -EINVAL; >+ >+ if (range == data->range) >+ return 0; >+ >+ mode = data->mode; >+ /* We need to go in standby mode to modify registers */ >+ ret = stk8312_set_mode(data, STK8312_MODE_STANDBY); >+ if (ret < 0) >+ return ret; >+ >+ ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH); >+ if (ret < 0) { >+ dev_err(&client->dev, "register read failed\n"); >+ return ret; >+ } >+ >+ masked_reg = ret & (~STK8312_RNG_MASK); >+ masked_reg |= range << STK8312_RNG_SHIFT; >+ >+ ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg); >+ if (ret < 0) >+ dev_err(&client->dev, "failed to change sensor range\n"); >+ else >+ data->range = range; >+ >+ return stk8312_set_mode(data, mode); >+} >+ >+static int stk8312_read_accel(struct stk8312_data *data, int axis) >+{ >+ int ret; >+ u8 reg; >+ int retries = STK8312_READ_RETRIES; >+ struct i2c_client *client = data->client; >+ >+ switch (axis) { >+ case IIO_MOD_X: >+ reg = STK8312_REG_XOUT; >+ break; >+ case IIO_MOD_Y: >+ reg = STK8312_REG_YOUT; >+ break; >+ case IIO_MOD_Z: >+ reg = STK8312_REG_ZOUT; >+ break; >+ default: >+ return -EINVAL; >+ } >+ >+ ret = i2c_smbus_read_byte_data(client, reg); >+ if (ret < 0) { >+ dev_err(&client->dev, "register read failed\n"); >+ return ret; >+ } >+ if (data->range == 0) { >+ /* 6bit mode */ >+ while (retries--) { >+ if (ret & STK8312_ALERT_MASK) { >+ /* The register is being updated. Try again. */ >+ msleep(20); >+ ret = i2c_smbus_read_byte_data(client, reg); >+ if (ret < 0) { >+ dev_err(&data->client->dev, >+ "register read failed\n"); >+ return ret; >+ } >+ } else { >+ ret &= STK8312_DATA6_MASK; >+ return sign_extend32(ret, 5); >+ } >+ } >+ dev_err(&data->client->dev, >+ "register read failed, data not ready\n"); >+ return -EIO; >+ } >+ /* 8bit mode */ >+ return sign_extend32(ret, 7); >+} >+ >+static int stk8312_read_raw(struct iio_dev *indio_dev, >+ struct iio_chan_spec const *chan, >+ int *val, int *val2, long mask) >+{ >+ struct stk8312_data *data = iio_priv(indio_dev); >+ >+ if (chan->type != IIO_ACCEL) >+ return -EINVAL; >+ >+ switch (mask) { >+ case IIO_CHAN_INFO_RAW: >+ mutex_lock(&data->lock); >+ *val = stk8312_read_accel(data, chan->channel2); >+ mutex_unlock(&data->lock); >+ return IIO_VAL_INT; >+ case IIO_CHAN_INFO_SCALE: >+ *val = stk8312_scale_table[data->range][0]; >+ *val2 = stk8312_scale_table[data->range][1]; >+ return IIO_VAL_INT_PLUS_MICRO; >+ } >+ >+ return -EINVAL; >+} >+ >+static int stk8312_write_raw(struct iio_dev *indio_dev, >+ struct iio_chan_spec const *chan, >+ int val, int val2, long mask) >+{ >+ int i; >+ int index = -1; >+ int ret; >+ struct stk8312_data *data = iio_priv(indio_dev); >+ >+ switch (mask) { >+ case IIO_CHAN_INFO_SCALE: >+ for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++) >+ if (val == stk8312_scale_table[i][0] && >+ val2 == stk8312_scale_table[i][1]) { >+ index = i; >+ break; >+ } >+ if (index < 0) >+ return -EINVAL; >+ >+ mutex_lock(&data->lock); >+ ret = stk8312_set_range(data, index); >+ mutex_unlock(&data->lock); >+ >+ return ret; >+ } >+ >+ return -EINVAL; >+} >+ >+static const struct iio_info stk8312_info = { >+ .driver_module = THIS_MODULE, >+ .read_raw = stk8312_read_raw, >+ .write_raw = stk8312_write_raw, >+ .attrs = &stk8312_attribute_group, >+}; >+ >+static int stk8312_init(struct iio_dev *indio_dev) >+{ >+ int ret; >+ struct stk8312_data *data = iio_priv(indio_dev); >+ struct i2c_client *client = data->client; >+ >+ /* A software reset is recommended at power-on */ >+ ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, >0x00); >+ if (ret < 0) >+ dev_err(&client->dev, "failed to reset sensor"); >+ >+ ret = stk8312_set_mode(data, STK8312_MODE_ACTIVE); >+ if (ret < 0) >+ dev_err(&client->dev, "failed to enable sensor"); >+ >+ return ret; >+} >+ >+static int stk8312_probe(struct i2c_client *client, >+ const struct i2c_device_id *id) >+{ >+ int ret; >+ struct iio_dev *indio_dev; >+ struct stk8312_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 = &stk8312_info; >+ indio_dev->name = STK8312_DRIVER_NAME; >+ indio_dev->modes = INDIO_DIRECT_MODE; >+ indio_dev->channels = stk8312_channels; >+ indio_dev->num_channels = ARRAY_SIZE(stk8312_channels); >+ >+ ret = stk8312_init(indio_dev); >+ if (ret < 0) { >+ dev_err(&client->dev, "sensor initialization failed\n"); >+ return ret; >+ } >+ >+ ret = iio_device_register(indio_dev); >+ if (ret < 0) { >+ dev_err(&client->dev, "device_register failed\n"); >+ stk8312_set_mode(data, STK8312_MODE_STANDBY); >+ } >+ >+ return ret; >+} >+ >+static int stk8312_remove(struct i2c_client *client) >+{ >+ struct iio_dev *indio_dev = i2c_get_clientdata(client); >+ >+ iio_device_unregister(indio_dev); >+ >+ return stk8312_set_mode(iio_priv(indio_dev), STK8312_MODE_STANDBY); >+} >+ >+#ifdef CONFIG_PM_SLEEP >+static int stk8312_suspend(struct device *dev) >+{ >+ struct stk8312_data *data; >+ >+ data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); >+ >+ return stk8312_set_mode(data, STK8312_MODE_STANDBY); >+} >+ >+static int stk8312_resume(struct device *dev) >+{ >+ struct stk8312_data *data; >+ >+ data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); >+ >+ return stk8312_set_mode(data, STK8312_MODE_ACTIVE); >+} >+ >+static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, >stk8312_resume); >+ >+#define STK8312_PM_OPS (&stk8312_pm_ops) >+#else >+#define STK8312_PM_OPS NULL >+#endif >+ >+static const struct i2c_device_id stk8312_i2c_id[] = { >+ {"STK8312", 0}, >+ {} >+}; >+ >+static const struct acpi_device_id stk8312_acpi_id[] = { >+ {"STK8312", 0}, >+ {} >+}; >+ >+MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id); >+ >+static struct i2c_driver stk8312_driver = { >+ .driver = { >+ .name = "stk8312", >+ .pm = STK8312_PM_OPS, >+ .acpi_match_table = ACPI_PTR(stk8312_acpi_id), >+ }, >+ .probe = stk8312_probe, >+ .remove = stk8312_remove, >+ .id_table = stk8312_i2c_id, >+}; >+ >+module_i2c_driver(stk8312_driver); >+ >+MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@xxxxxxxxx>"); >+MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver"); >+MODULE_LICENSE("GPL v2"); -- Sent from my Android device with K-9 Mail. 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