> 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 that explains things :) probably worth a comment thanks, p. > 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. Please excuse my brevity. > -- > 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 > -- 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
