This a patch re-submission taking into account feebdack from Peter and Tomasz.
Thank you for your feedback
Ludovic
Signed-off-by: Ludovic <ludovic.tancerel@xxxxxxxxxxxxxxxxx>
---
drivers/iio/pressure/Kconfig | 9 +
drivers/iio/pressure/Makefile | 1 +
drivers/iio/pressure/ms5637.c | 457 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 467 insertions(+)
create mode 100644 drivers/iio/pressure/ms5637.c
diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
index fa62950..69675ef2 100644
--- a/drivers/iio/pressure/Kconfig
+++ b/drivers/iio/pressure/Kconfig
@@ -78,6 +78,15 @@ config MS5611_SPI
To compile this driver as a module, choose M here: the module will
be called ms5611_spi.
+config MS5637
+ tristate "MS5637 pressure & temperature sensor"
+ depends on I2C
+ help
+ If you say yes here you get support for the Measurement Specialties
+ MS5637 pressure and temperature sensor.
+
+ This driver can also be built as a module. If so, the module will
+ be called ms5637.
config IIO_ST_PRESS
tristate "STMicroelectronics pressure sensor Driver"
diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile
index a4f98f8..46571c96 100644
--- a/drivers/iio/pressure/Makefile
+++ b/drivers/iio/pressure/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_MPL3115) += mpl3115.o
obj-$(CONFIG_MS5611) += ms5611_core.o
obj-$(CONFIG_MS5611_I2C) += ms5611_i2c.o
obj-$(CONFIG_MS5611_SPI) += ms5611_spi.o
+obj-$(CONFIG_MS5637) += ms5637.o
obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o
st_pressure-y := st_pressure_core.o
st_pressure-$(CONFIG_IIO_BUFFER) += st_pressure_buffer.o
diff --git a/drivers/iio/pressure/ms5637.c b/drivers/iio/pressure/ms5637.c
new file mode 100644
index 0000000..bda7206
--- /dev/null
+++ b/drivers/iio/pressure/ms5637.c
@@ -0,0 +1,457 @@
+/*
+ * ms5637.c - Support for Measurement-Specialties ms5637
+ * pressure & temperature sensor
+ *
+ * Copyright (c) 2014 Measurement-Specialties
+ *
+ * Licensed under the GPL-2.
+ *
+ * (7-bit I2C slave address 0x76)
+ *
+ */
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/stat.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+
+/* MS5637 Commands */
+#define MS5637_RESET 0x1E
+#define MS5637_TEMPERATURE_CONVERSION_START 0x50
+#define MS5637_PRESSURE_CONVERSION_START 0x40
+#define MS5637_ADC_READ 0x00
+#define MS5637_PROM_READ 0xA0
+#define MS5637_PROM_ELEMENTS_NB 7
+
+#define MS5637_CONVERSION_SLEEP(index) \
+ usleep_range(ms5637_conversion_time[index],\
+ ms5637_conversion_time[index] + 3000)
+
+static const u16 ms5637_conversion_time[6] = { 1000, 2000,
+ 3000, 5000,
+ 9000, 17000 };
+
+static const int ms5637_samp_freq[6][2] = { {1800, 0}, {900, 0},
+ {450, 0}, {225, 0},
+ {112, 500000}, {56, 250000}
+ };
+
+struct ms5637_dev {
+ struct i2c_client *client;
+ struct mutex lock; /* Mutex protecting this data structure */
+ /* Added element for CRC computation */
+ u16 calibration_coeffs[MS5637_PROM_ELEMENTS_NB + 1];
+ unsigned long last_update;
+ int temperature;
+ unsigned int pressure;
+ u8 resolution_index;
+};
+
+static int ms5637_get_calibration_coeffs(struct ms5637_dev *dev_data,
+ u8 index, u16 *word)
+{
+ int ret;
+
+ ret = i2c_smbus_read_word_swapped(dev_data->client,
+ MS5637_PROM_READ + (index << 1));
+ if (ret < 0)
+ return ret;
+ *word = ret;
+ return 0;
+}
+
+static bool ms5637_crc_check(u16 *n_prom, u8 crc)
+{
+ unsigned int cnt, n_bit;
+ u16 n_rem, crc_read;
+
+ n_rem = 0x0000;
+ crc_read = n_prom[0];
+ n_prom[MS5637_PROM_ELEMENTS_NB] = 0;
+ n_prom[0] &= 0x0FFF; /* Clear the CRC computation part */
+
+ for (cnt = 0; cnt < (MS5637_PROM_ELEMENTS_NB + 1) * 2; cnt++) {
+ if (cnt % 2 == 1)
+ n_rem ^= n_prom[cnt >> 1] & 0x00FF;
+ else
+ n_rem ^= n_prom[cnt >> 1] >> 8;
+
+ for (n_bit = 8; n_bit > 0; n_bit--) {
+ if (n_rem & 0x8000)
+ n_rem = (n_rem << 1) ^ 0x3000;
+ else
+ n_rem <<= 1;
+ }
+ }
+ n_rem >>= 12;
+ n_prom[0] = crc_read;
+ return n_rem == crc;
+}
+
+static int ms5637_fill_calibration_coeffs(struct ms5637_dev *dev_data)
+{
+ int i, ret;
+
+ for (i = 0; i < MS5637_PROM_ELEMENTS_NB; i++) {
+ ret = ms5637_get_calibration_coeffs(
+ dev_data, i,
+ &dev_data->calibration_coeffs[i]);
+
+ if (ret < 0) {
+ dev_err(&dev_data->client->dev,
+ "Unable to get calibration coefficients at address %d\n",
+ i + 1);
+ return ret;
+ }
+
+ dev_dbg(&dev_data->client->dev, "Coeff %d : %d", i,
+ dev_data->calibration_coeffs[i]);
+ }
+
+ if ( ms5637_crc_check(
+ dev_data->calibration_coeffs,
+ (dev_data->calibration_coeffs[0] & 0xF000) >> 12) == false) {
+ dev_err(&dev_data->client->dev,
+ "Calibration coefficients crc check error\n");
+ return -ENODEV;
+ }
+ return 0;
+}
+
+static int ms5637_read_adc_value(struct ms5637_dev *dev_data, u32 *adc_value)
+{
+ int ret;
+ u8 buf[3];
+
+ ret =
+ i2c_smbus_read_i2c_block_data(dev_data->client, MS5637_ADC_READ, 3,
+ buf);
+ if (ret < 0)
+ return ret;
+
+ dev_dbg(&dev_data->client->dev, "ADC raw value : %x %x %x\n", buf[0],
+ buf[1], buf[2]);
+
+ *adc_value = (buf[0] << 16) + (buf[1] << 8) + buf[2];
+
+ return 0;
+}
+
+static int ms5637_conversion_and_read_adc(struct ms5637_dev *dev_data,
+ u32 *t_adc, u32 *p_adc)
+{
+ int ret;
+
+ /* Trigger Temperature conversion */
+ ret = i2c_smbus_write_byte(dev_data->client,
+ MS5637_TEMPERATURE_CONVERSION_START
+ + dev_data->resolution_index * 2);
+ if (ret < 0)
+ return ret;
+ MS5637_CONVERSION_SLEEP(dev_data->resolution_index);
+
+ /* Retrieve ADC value */
+ ret = ms5637_read_adc_value(dev_data, t_adc);
+ if (ret < 0)
+ return ret;
+
+ /* Trigger Pressure conversion */
+ ret = i2c_smbus_write_byte(dev_data->client,
+ MS5637_PRESSURE_CONVERSION_START
+ + dev_data->resolution_index * 2);
+ if (ret < 0)
+ return ret;
+ MS5637_CONVERSION_SLEEP(dev_data->resolution_index);
+
+ /* Retrieve ADC value */
+ ret = ms5637_read_adc_value(dev_data, p_adc);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int ms5637_read_temperature_and_pressure(struct ms5637_dev *dev_data)
+{
+ int ret = 0;
+ u32 t_adc, p_adc;
+ s32 dt, temp;
+ s64 off, sens, t2, off2, sens2;
+
+ mutex_lock(&dev_data->lock);
+
+ if (time_after(jiffies, dev_data->last_update + HZ / 2)) {
+ ret = ms5637_conversion_and_read_adc(dev_data, &t_adc, &p_adc);
+ if (ret < 0) {
+ dev_err(&dev_data->client->dev,
+ "Unable to make sensor adc conversion\n");
+ goto out;
+ }
+
+ dt = (s32)t_adc - (dev_data->calibration_coeffs[5] << 8);
+
+ /* Actual temperature = 2000 + dT * TEMPSENS */
+ temp =
+ 2000 + (((s64)dt * dev_data->calibration_coeffs[6]) >> 23);
+
+ /* Second order temperature compensation */
+ if (temp < 2000) {
+ s64 tmp = (s64)temp - 2000;
+
+ t2 = (3 * ((s64)dt * (s64)dt)) >> 33;
+ off2 = (61 * tmp * tmp) >> 4;
+ sens2 = (29 * tmp * tmp) >> 4;
+
+ if (temp < -1500) {
+ s64 tmp = (s64)temp + 1500;
+
+ off2 += 17 * tmp * tmp;
+ sens2 += 9 * tmp * tmp;
+ }
+ } else {
+ t2 = (5 * ((s64)dt * (s64)dt)) >> 38;
+ off2 = 0;
+ sens2 = 0;
+ }
+
+ /* OFF = OFF_T1 + TCO * dT */
+ off = (((s64)dev_data->calibration_coeffs[2]) << 17) +
+ ((((s64)dev_data->calibration_coeffs[4]) * (s64)dt) >> 6);
+ off -= off2;
+
+ /* Sensitivity at actual temperature = SENS_T1 + TCS * dT */
+ sens = (((s64)dev_data->calibration_coeffs[1]) << 16)
+ + (((s64)dev_data->calibration_coeffs[3] * dt) >> 7);
+ sens -= sens2;
+
+ /* Temperature compensated pressure = D1 * SENS - OFF */
+ dev_data->temperature = (temp - t2) * 10;
+ dev_data->pressure = (u32)(((((s64)p_adc * sens) >> 21)
+ - off) >> 15);
+
+ dev_data->last_update = jiffies;
+ }
+ out:
+ mutex_unlock(&dev_data->lock);
+
+ return ret >= 0 ? 0 : ret;
+}
+
+static int ms5637_get_int_plus_micros_index(const int (*vals)[2], int n,
+ int val, int val2)
+{
+ while (n-- > 0)
+ if (val == vals[n][0] && val2 == vals[n][1])
+ return n;
+ return -EINVAL;
+}
+
+static int ms5637_get_samp_freq_index(struct ms5637_dev *dev_data,
+ int val, int val2)
+{
+ return ms5637_get_int_plus_micros_index(ms5637_samp_freq,
+ ARRAY_SIZE(ms5637_samp_freq), val, val2);
+}
+
+static ssize_t ms5637_show_int_plus_micros(char *buf,
+ const int (*vals)[2], int n)
+{
+ size_t len = 0;
+
+ while (n-- > 0)
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "%d.%06d ", vals[n][0], vals[n][1]);
+
+ /* replace trailing space by newline */
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
+static ssize_t ms5637_show_samp_freq_avail(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return ms5637_show_int_plus_micros(buf, ms5637_samp_freq,
+ ARRAY_SIZE(ms5637_samp_freq));
+}
+
+static int ms5637_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int *val,
+ int *val2, long mask)
+{
+ int ret;
+ struct ms5637_dev *dev_data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_PROCESSED:
+ ret = ms5637_read_temperature_and_pressure(dev_data);
+ if (ret)
+ goto err;
+ switch (channel->type) {
+ case IIO_TEMP: /* in °C */
+ *val = dev_data->temperature / 1000;
+ *val2 = (dev_data->temperature % 1000) * 1000;
+ break;
+ case IIO_PRESSURE: /* in kPa */
+ *val = dev_data->pressure / 1000;
+ *val2 = (dev_data->pressure % 1000) * 1000;
+ break;
+ default:
+ return -EINVAL;
+ }
+ break;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = ms5637_samp_freq[dev_data->resolution_index][0];
+ *val2 = ms5637_samp_freq[dev_data->resolution_index][1];
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return IIO_VAL_INT_PLUS_MICRO;
+ err:
+ dev_err(&indio_dev->dev, "Device read error\n");
+ return ret;
+}
+
+static int ms5637_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct ms5637_dev *dev_data = iio_priv(indio_dev);
+ int i;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ i = ms5637_get_samp_freq_index(dev_data, val, val2);
+ if (i < 0)
+ return -EINVAL;
+
+ dev_data->resolution_index = i;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_chan_spec ms5637_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ },
+ {
+ .type = IIO_PRESSURE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ }
+};
+
+static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(ms5637_show_samp_freq_avail);
+
+static struct attribute *ms5637_attributes[] = {
+ &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ms5637_attribute_group = {
+ .attrs = ms5637_attributes,
+};
+
+static const struct iio_info ms5637_info = {
+ .read_raw = ms5637_read_raw,
+ .write_raw = ms5637_write_raw,
+ .attrs = &ms5637_attribute_group,
+ .driver_module = THIS_MODULE,
+};
+
+static int ms5637_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct ms5637_dev *dev_data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_READ_WORD_DATA)) {
+ dev_err(&client->dev,
+ "Adapter does not support SMBus read word transactions\n");
+ return -ENODEV;
+ }
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_WRITE_BYTE)) {
+ dev_err(&client->dev,
+ "Adapter does not support SMBus write byte transactions\n");
+ return -ENODEV;
+ }
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
+ dev_err(&client->dev,
+ "Adapter does not support SMBus read block transactions\n");
+ return -ENODEV;
+ }
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ dev_data = iio_priv(indio_dev);
+ dev_data->client = client;
+ dev_data->resolution_index = 5;
+ dev_data->last_update = jiffies - HZ / 2;
+ mutex_init(&dev_data->lock);
+
+ indio_dev->info = &ms5637_info;
+ indio_dev->name = id->name;
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = ms5637_channels;
+ indio_dev->num_channels = ARRAY_SIZE(ms5637_channels);
+
+ i2c_set_clientdata(client, indio_dev);
+ ret = i2c_smbus_write_byte(client, MS5637_RESET);
+ if (ret < 0)
+ return ret;
+ usleep_range(3000, 6000);
+
+ ret = ms5637_fill_calibration_coeffs(dev_data);
+ if (ret < 0)
+ return ret;
+
+ ret = devm_iio_device_register(&client->dev, indio_dev);
+ if (ret < 0)
+ return ret;
+
+ dev_dbg(&client->dev, "Driver initialization done");
+ return 0;
+}
+
+static const struct i2c_device_id ms5637_id[] = {
+ {"ms5637", 0},
+ {}
+};
+
+static struct i2c_driver ms5637_driver = {
+ .probe = ms5637_probe,
+ .id_table = ms5637_id,
+ .driver = {
+ .name = "ms5637",
+ .owner = THIS_MODULE,
+ },
+};
+
+module_i2c_driver(ms5637_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Measurement-Specialties ms5637 temperature & pressure driver");
+MODULE_AUTHOR("William Markezana <william.markezana@xxxxxxxxxxxxx>");
+MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@xxxxxxxxxxxxxxxxx>");
--
2.3.7
--
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