Peter Meerwald schrieb: > 16-bit pressure and temperature sensor > > the chip can do I2C and SPI, only the I2C interface is supported > by the driver at the moment > > datasheet: http://www.epcos.com/inf/57/ds/T5400.pdf > application note: http://www.epcos.com/blob/993154/download/1/t5403-applicationnote.pdf > > an out-of-tree driver targetting the input subsystem is at > https://github.com/unixphere/t5400, it was rejected here: > http://comments.gmane.org/gmane.linux.kernel.input/28107 > > Signed-off-by: Peter Meerwald <pmeerw@xxxxxxxxxx> > Cc: Stefan Nilsson <stefan.nilsson@xxxxxxxxxxxxx> > --- > drivers/iio/pressure/Kconfig | 10 ++ > drivers/iio/pressure/Makefile | 1 + > drivers/iio/pressure/t5403.c | 268 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 279 insertions(+) > create mode 100644 drivers/iio/pressure/t5403.c > > diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig > index ffac8ac..15afbc9 100644 > --- a/drivers/iio/pressure/Kconfig > +++ b/drivers/iio/pressure/Kconfig > @@ -70,4 +70,14 @@ config IIO_ST_PRESS_SPI > depends on IIO_ST_PRESS > depends on IIO_ST_SENSORS_SPI > > +config T5403 > + tristate "EPCOS T5403 digital barometric pressure sensor driver" > + depends on I2C > + help > + Say yes here to build support for the EPCOS T5403 pressure sensor > + connected via I2C. > + > + To compile this driver as a module, choose M here: the module > + will be called t5403. > + > endmenu > diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile > index c53d250..90a37e8 100644 > --- a/drivers/iio/pressure/Makefile > +++ b/drivers/iio/pressure/Makefile > @@ -9,6 +9,7 @@ obj-$(CONFIG_MPL3115) += mpl3115.o > obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o > st_pressure-y := st_pressure_core.o > st_pressure-$(CONFIG_IIO_BUFFER) += st_pressure_buffer.o > +obj-$(CONFIG_T5403) += t5403.o > > obj-$(CONFIG_IIO_ST_PRESS_I2C) += st_pressure_i2c.o > obj-$(CONFIG_IIO_ST_PRESS_SPI) += st_pressure_spi.o > diff --git a/drivers/iio/pressure/t5403.c b/drivers/iio/pressure/t5403.c > new file mode 100644 > index 0000000..cb01d6d > --- /dev/null > +++ b/drivers/iio/pressure/t5403.c > @@ -0,0 +1,268 @@ > +/* > + * t5403.c - Support for EPCOS T5403 pressure/temperature sensor > + * > + * Copyright (c) 2014 Peter Meerwald <pmeerw@xxxxxxxxxx> > + * > + * 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. > + * > + * (7-bit I2C slave address 0x77) > + * > + * TODO: end-of-conversion irq > + */ > + > +#include <linux/module.h> > +#include <linux/i2c.h> > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > +#include <linux/delay.h> > + > +#define T5403_DATA 0xf5 /* data, LSB first, 16 bit */ > +#define T5403_CALIB_DATA 0x8e /* 10 calibration coeff., LSB first, 16 bit */ > +#define T5403_SLAVE_ADDR 0x88 /* I2C slave address, 0x77 */ > +#define T5403_COMMAND 0xf1 > + > +/* command bits */ > +#define T5403_MODE_SHIFT 3 /* conversion time: 2, 8, 16, 66 ms */ > +#define T5403_PT BIT(1) /* 0 .. pressure, 1 .. temperature measurement */ > +#define T5403_SCO BIT(0) /* start conversion */ > + > +#define T5403_MODE_LOW 0 > +#define T5403_MODE_STANDARD 1 > +#define T5403_MODE_HIGH 1 ^That needs to be 2. > +#define T5403_MODE_ULTRA_HIGH 3 > + > +#define T5403_I2C_MASK (~BIT(7)) > +#define T5403_I2C_ADDR 0x77 > + > +static const int t5403_pressure_conv_ms[] = {2, 8, 16, 66}; > + > +struct t5403_data { > + struct i2c_client *client; > + struct mutex lock; > + int mode; > + __le16 c[10]; > +}; > + > +#define T5403_C_U16(i) le16_to_cpu(data->c[(i) - 1]) > +#define T5403_C(i) sign_extend32(T5403_C_U16(i), 15) > + > +static int t5403_read(struct t5403_data *data, bool pressure) > +{ > + int wait_time = 3; /* wakeup time in ms */ > + > + int ret = i2c_smbus_write_byte_data(data->client, T5403_COMMAND, > + (pressure ? (data->mode << T5403_MODE_SHIFT) : T5403_PT) | > + T5403_SCO); This is a bit confusing. Although not causing any harm, I would keep sending data->mode unchanged at all time and just set/clear the pt bits as needed. > + if (ret < 0) > + return ret; > + > + wait_time += pressure ? t5403_pressure_conv_ms[data->mode] : 2; > + > + msleep(wait_time); > + > + return i2c_smbus_read_word_data(data->client, T5403_DATA); > +} > + > +static int t5403_comp_pressure(struct t5403_data *data, int *val, int *val2) > +{ > + int ret; > + s16 t_r; > + u16 p_r; > + s32 S, O, X; > + > + mutex_lock(&data->lock); > + > + ret = t5403_read(data, false); > + if (ret < 0) > + goto done; > + t_r = ret; > + > + ret = t5403_read(data, true); > + if (ret < 0) > + goto done; > + p_r = ret; > + > + /* see EPCOS application note */ What about simplifying those equations, they look to me like this: S = (c9 * t_r^3)/2^46 + (c5 * t_r^2)/2^34 + (c4 * t_r)/2^17 + c3 O = (c9 * t_r^3)/2^31 + (c8 * t_r^2)/2^19 + (c7 * t_r)/2^3 + c_6 * 2^14 That should barely fit into s64. > + S = T5403_C_U16(3) + (s32) T5403_C_U16(4) * t_r / 0x20000 + > + T5403_C(5) * t_r / 0x8000 * t_r / 0x80000 + > + T5403_C(9) * t_r / 0x8000 * t_r / 0x8000 * t_r / 0x10000; > + > + O = T5403_C(6) * 0x4000 + T5403_C(7) * t_r / 8 + > + T5403_C(8) * t_r / 0x8000 * t_r / 16 + > + T5403_C(9) * t_r / 0x8000 * t_r / 0x10000 * t_r; > + > + X = (S * p_r + O) / 0x4000; > + > + X += ((X - 75000) * (X - 75000) / 0x10000 - 9537) * > + T5403_C(10) / 0x10000; > + > + *val = X / 1000; > + *val2 = (X % 1000) * 1000; > + > +done: > + mutex_unlock(&data->lock); > + return ret; > +} > + > +static int t5403_comp_temp(struct t5403_data *data, int *val) > +{ > + int ret; > + s16 t_r; > + > + mutex_lock(&data->lock); > + ret = t5403_read(data, false); > + if (ret < 0) > + goto done; > + t_r = ret; > + > + /* see EPCOS application note */ > + *val = ((s32) T5403_C_U16(1) * t_r / 0x100 + > + (s32) T5403_C_U16(2) * 0x40) * 1000 / 0x10000; > + > +done: > + mutex_unlock(&data->lock); > + return ret; > +} > + > +static int t5403_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + struct t5403_data *data = iio_priv(indio_dev); > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_PROCESSED: > + switch (chan->type) { > + case IIO_PRESSURE: > + ret = t5403_comp_pressure(data, val, val2); > + if (ret < 0) > + return ret; > + return IIO_VAL_INT_PLUS_MICRO; > + case IIO_TEMP: > + ret = t5403_comp_temp(data, val); > + if (ret < 0) > + return ret; > + return IIO_VAL_INT; > + default: > + return -EINVAL; > + } > + case IIO_CHAN_INFO_INT_TIME: > + *val = 0; > + *val2 = t5403_pressure_conv_ms[data->mode] * 1000; > + return IIO_VAL_INT_PLUS_MICRO; > + default: > + return -EINVAL; > + } > +} > + > +static int t5403_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + struct t5403_data *data = iio_priv(indio_dev); > + int i; > + Check for the right mask (IIO_CHAN_INFO_INT_TIME). > + for (i = 0; i < ARRAY_SIZE(t5403_pressure_conv_ms); i++) > + if (val == 0 && val2 == t5403_pressure_conv_ms[i] * 1000) { > + mutex_lock(&data->lock); > + data->mode = i; > + mutex_unlock(&data->lock); > + return 0; > + } > + return -EINVAL; > +} > + > +static const struct iio_chan_spec t5403_channels[] = { > + { > + .type = IIO_PRESSURE, > + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | > + BIT(IIO_CHAN_INFO_INT_TIME), > + }, > + { > + .type = IIO_TEMP, > + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), > + }, > +}; > + > +static IIO_CONST_ATTR_INT_TIME_AVAIL("0.002 0.008 0.016 0.066"); > + > +static struct attribute *t5403_attributes[] = { > + &iio_const_attr_integration_time_available.dev_attr.attr, > + NULL > +}; > + > +static const struct attribute_group t5403_attribute_group = { > + .attrs = t5403_attributes, > +}; > + > +static const struct iio_info t5403_info = { > + .read_raw = &t5403_read_raw, > + .write_raw = &t5403_write_raw, > + .attrs = &t5403_attribute_group, > + .driver_module = THIS_MODULE, > +}; > + > +static int t5403_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct t5403_data *data; > + struct iio_dev *indio_dev; > + int ret; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA | > + I2C_FUNC_SMBUS_I2C_BLOCK)) > + return -ENODEV; > + > + ret = i2c_smbus_read_byte_data(client, T5403_SLAVE_ADDR); > + if (ret < 0) > + return ret; > + if ((ret & T5403_I2C_MASK) != T5403_I2C_ADDR) > + return -ENODEV; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); > + if (!indio_dev) > + return -ENOMEM; > + > + data = iio_priv(indio_dev); > + data->client = client; > + mutex_init(&data->lock); > + > + i2c_set_clientdata(client, indio_dev); > + indio_dev->info = &t5403_info; > + indio_dev->name = id->name; > + indio_dev->dev.parent = &client->dev; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = t5403_channels; > + indio_dev->num_channels = ARRAY_SIZE(t5403_channels); > + > + data->mode = T5403_MODE_STANDARD; > + > + ret = i2c_smbus_read_i2c_block_data(data->client, T5403_CALIB_DATA, > + sizeof(data->c), (u8 *) data->c); > + if (ret < 0) > + return ret; > + > + return devm_iio_device_register(&client->dev, indio_dev); > +} > + > +static const struct i2c_device_id t5403_id[] = { > + { "t5403", 0 }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, t5403_id); > + > +static struct i2c_driver t5403_driver = { > + .driver = { > + .name = "t5403", > + }, > + .probe = t5403_probe, > + .id_table = t5403_id, > +}; > +module_i2c_driver(t5403_driver); > + > +MODULE_AUTHOR("Peter Meerwald <pmeerw@xxxxxxxxxx>"); > +MODULE_DESCRIPTION("EPCOS T5403 pressure/temperature sensor driver"); > +MODULE_LICENSE("GPL"); -- 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
