On 10/04/16 21:52, Marek Vasut wrote:
> Add support for HopeRF pressure and temperature sensor.
>
> This device uses two fixed I2C addresses, one for storing
> calibration coefficients and another for accessing the ADC.
>
> Signed-off-by: Marek Vasut <marex@xxxxxxx>
> Cc: Matt Ranostay <mranostay@xxxxxxxxx>
> Cc: Jonathan Cameron <jic23@xxxxxxxxxx>
Sorry I didn't get to this earlier in the week.
Unfortunately the resulting scales don't match the standard ABI for these
two channel types.
Otherwise, looks good. I've cc'd the devicetree list and maintainers.
The binding is trivial I think, but always good to give people a
opportunity to comment.
Jonathan
> ---
> V2: - Expand the binding document with more details on the XCLR pin
> - Switch from IIO_CHAN_INFO_PROCESSED to RAW + SCALE
> - Add failpath into hp03_update_temp_pressure() for the case
> when ADC readout fails. This correctly sets the XCLR pin back
> to LO now.
> - Add comment explaining the need for allocation of child device
> in hp03_probe().
> V3: - Fix indent in the DT binding documentation
> - Report raw pressure and temperature unmodified
Good
> - Report pressure scale to be 1 , since pressure is in Pa
Standard units for pressure (see Documentation/ABI/testing/sysfs-bus-iio
are KPa so it wants to report 0.001)
> - Report temperature scale to be 0.01 , since temp is in 0.01C steps
Unfortunately the documented base unit for temp (originally from hwmon before
we started going for SI units every time) are milli Celcius. Thus the value
reported * scale should end up in milli degrees Celcius. Hence if it is in 0.01
steps the scale should be 0.1
> ---
> .../devicetree/bindings/iio/pressure/hp03.txt | 17 ++
> drivers/iio/pressure/Kconfig | 11 +
> drivers/iio/pressure/Makefile | 1 +
> drivers/iio/pressure/hp03.c | 307 +++++++++++++++++++++
> 4 files changed, 336 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/pressure/hp03.txt
> create mode 100644 drivers/iio/pressure/hp03.c
>
> diff --git a/Documentation/devicetree/bindings/iio/pressure/hp03.txt b/Documentation/devicetree/bindings/iio/pressure/hp03.txt
> new file mode 100644
> index 0000000..54e7e70
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/pressure/hp03.txt
> @@ -0,0 +1,17 @@
> +HopeRF HP03 digital pressure/temperature sensors
> +
> +Required properties:
> +- compatible: must be "hoperf,hp03"
> +- xclr-gpio: must be device tree identifier of the XCLR pin.
> + The XCLR pin is a reset of the ADC in the chip,
> + it must be pulled HI before the conversion and
> + readout of the value from the ADC registers and
> + pulled LO afterward.
> +
> +Example:
> +
> +hp03@0x77 {
> + compatible = "hoperf,hp03";
> + reg = <0x77>;
> + xclr-gpio = <&portc 0 0x0>;
> +};
Whilst it is simple enough I doubt anyone cares, all bindings should be
cc'd to devicetree list and maintainers (I'll add them).
> diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
> index 8de0192..54c6165 100644
> --- a/drivers/iio/pressure/Kconfig
> +++ b/drivers/iio/pressure/Kconfig
> @@ -30,6 +30,17 @@ config HID_SENSOR_PRESS
> To compile this driver as a module, choose M here: the module
> will be called hid-sensor-press.
>
> +config HP03
> + tristate "Hope RF HP03 temperature and pressure sensor driver"
> + depends on I2C
> + select REGMAP_I2C
> + help
> + Say yes here to build support for Hope RF HP03 pressure and
> + temperature sensor.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called hp03.
> +
> config MPL115
> tristate
>
> diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile
> index 6e60863..17d6e7a 100644
> --- a/drivers/iio/pressure/Makefile
> +++ b/drivers/iio/pressure/Makefile
> @@ -5,6 +5,7 @@
> # When adding new entries keep the list in alphabetical order
> obj-$(CONFIG_BMP280) += bmp280.o
> obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o
> +obj-$(CONFIG_HP03) += hp03.o
> obj-$(CONFIG_MPL115) += mpl115.o
> obj-$(CONFIG_MPL115_I2C) += mpl115_i2c.o
> obj-$(CONFIG_MPL115_SPI) += mpl115_spi.o
> diff --git a/drivers/iio/pressure/hp03.c b/drivers/iio/pressure/hp03.c
> new file mode 100644
> index 0000000..202a028
> --- /dev/null
> +++ b/drivers/iio/pressure/hp03.c
> @@ -0,0 +1,307 @@
> +/*
> + * Copyright (c) 2016 Marek Vasut <marex@xxxxxxx>
> + *
> + * Driver for Hope RF HP03 digital temperature and pressure sensor.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#define pr_fmt(fmt) "hp03: " fmt
> +
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +/*
> + * The HP03 sensor occupies two fixed I2C addresses:
> + * 0x50 ... read-only EEPROM with calibration data
> + * 0x77 ... read-write ADC for pressure and temperature
> + */
> +#define HP03_EEPROM_ADDR 0x50
> +#define HP03_ADC_ADDR 0x77
> +
> +#define HP03_EEPROM_CX_OFFSET 0x10
> +#define HP03_EEPROM_AB_OFFSET 0x1e
> +#define HP03_EEPROM_CD_OFFSET 0x20
> +
> +#define HP03_ADC_WRITE_REG 0xff
> +#define HP03_ADC_READ_REG 0xfd
> +#define HP03_ADC_READ_PRESSURE 0xf0 /* D1 in datasheet */
> +#define HP03_ADC_READ_TEMP 0xe8 /* D2 in datasheet */
> +
> +struct hp03_priv {
> + struct i2c_client *client;
> + struct mutex lock;
> + struct gpio_desc *xclr_gpio;
> +
> + struct i2c_client *eeprom_client;
> + struct regmap *eeprom_regmap;
> +
> + s32 pressure; /* kPa */
> + s32 temp; /* Deg. C */
> +};
> +
> +static const struct iio_chan_spec hp03_channels[] = {
> + {
> + .type = IIO_PRESSURE,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
> + },
> + {
> + .type = IIO_TEMP,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
> + },
> +};
> +
> +static bool hp03_is_writeable_reg(struct device *dev, unsigned int reg)
> +{
> + return false;
> +}
> +
> +static bool hp03_is_volatile_reg(struct device *dev, unsigned int reg)
> +{
> + return false;
> +}
> +
> +static const struct regmap_config hp03_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> +
> + .max_register = HP03_EEPROM_CD_OFFSET + 1,
> + .cache_type = REGCACHE_RBTREE,
> +
> + .writeable_reg = hp03_is_writeable_reg,
> + .volatile_reg = hp03_is_volatile_reg,
> +};
> +
> +static int hp03_get_temp_pressure(struct hp03_priv *priv, const u8 reg)
> +{
> + int ret;
> +
> + ret = i2c_smbus_write_byte_data(priv->client, HP03_ADC_WRITE_REG, reg);
> + if (ret < 0)
> + return ret;
> +
> + msleep(50); /* Wait for conversion to finish */
> +
> + return i2c_smbus_read_word_data(priv->client, HP03_ADC_READ_REG);
> +}
> +
> +static int hp03_update_temp_pressure(struct hp03_priv *priv)
> +{
> + struct device *dev = &priv->client->dev;
> + u8 coefs[18];
> + u16 cx_val[7];
> + int ab_val, d1_val, d2_val, diff_val, dut, off, sens, x;
> + int i, ret;
> +
> + /* Sample coefficients from EEPROM */
> + ret = regmap_bulk_read(priv->eeprom_regmap, HP03_EEPROM_CX_OFFSET,
> + coefs, sizeof(coefs));
> + if (ret < 0) {
> + dev_err(dev, "Failed to read EEPROM (reg=%02x)\n",
> + HP03_EEPROM_CX_OFFSET);
> + return ret;
> + }
> +
> + /* Sample Temperature and Pressure */
> + gpiod_set_value_cansleep(priv->xclr_gpio, 1);
> +
> + ret = hp03_get_temp_pressure(priv, HP03_ADC_READ_PRESSURE);
> + if (ret < 0) {
> + dev_err(dev, "Failed to read pressure\n");
> + goto err_adc;
> + }
> + d1_val = ret;
> +
> + ret = hp03_get_temp_pressure(priv, HP03_ADC_READ_TEMP);
> + if (ret < 0) {
> + dev_err(dev, "Failed to read temperature\n");
> + goto err_adc;
> + }
> + d2_val = ret;
> +
> + gpiod_set_value_cansleep(priv->xclr_gpio, 0);
> +
> + /* The Cx coefficients and Temp/Pressure values are MSB first. */
> + for (i = 0; i < 7; i++)
> + cx_val[i] = (coefs[2 * i] << 8) | (coefs[(2 * i) + 1] << 0);
> + d1_val = ((d1_val >> 8) & 0xff) | ((d1_val & 0xff) << 8);
> + d2_val = ((d2_val >> 8) & 0xff) | ((d2_val & 0xff) << 8);
> +
> + /* Coefficient voodoo from the HP03 datasheet. */
> + if (d2_val >= cx_val[4])
> + ab_val = coefs[14]; /* A-value */
> + else
> + ab_val = coefs[15]; /* B-value */
> +
> + diff_val = d2_val - cx_val[4];
> + dut = (ab_val * (diff_val >> 7) * (diff_val >> 7)) >> coefs[16];
> + dut = diff_val - dut;
> +
> + off = (cx_val[1] + (((cx_val[3] - 1024) * dut) >> 14)) * 4;
> + sens = cx_val[0] + ((cx_val[2] * dut) >> 10);
> + x = ((sens * (d1_val - 7168)) >> 14) - off;
> +
> + priv->pressure = ((x * 100) >> 5) + (cx_val[6] * 10);
> + priv->temp = 250 + ((dut * cx_val[5]) >> 16) - (dut >> coefs[17]);
> +
> + return 0;
> +
> +err_adc:
> + gpiod_set_value_cansleep(priv->xclr_gpio, 0);
> + return ret;
> +}
> +
> +static int hp03_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct hp03_priv *priv = iio_priv(indio_dev);
> + int ret;
> +
> + mutex_lock(&priv->lock);
> + ret = hp03_update_temp_pressure(priv);
> + mutex_unlock(&priv->lock);
> +
> + if (ret)
> + return ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + switch (chan->type) {
> + case IIO_PRESSURE:
> + *val = priv->pressure;
> + return IIO_VAL_INT;
> + case IIO_TEMP:
> + *val = priv->temp;
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> + break;
> + case IIO_CHAN_INFO_SCALE:
> + switch (chan->type) {
> + case IIO_PRESSURE:
> + *val = 1;
> + return IIO_VAL_INT;
*val = 0, *val2 = 1000;
return IIO_VAL_INT_PLUS_MICRO;
> + case IIO_TEMP:
> + *val = 0;
> + *val2 = 10000;
Val2 should I think be 100000 giving scale * lsb of 0.001 degrees.
> + return IIO_VAL_INT_PLUS_MICRO;
> + default:
> + return -EINVAL;
> + }
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static const struct iio_info hp03_info = {
> + .driver_module = THIS_MODULE,
> + .read_raw = &hp03_read_raw,
> +};
> +
> +static int hp03_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct device *dev = &client->dev;
> + struct iio_dev *indio_dev;
> + struct hp03_priv *priv;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + priv = iio_priv(indio_dev);
> + priv->client = client;
> + mutex_init(&priv->lock);
> +
> + indio_dev->dev.parent = dev;
> + indio_dev->name = id->name;
> + indio_dev->channels = hp03_channels;
> + indio_dev->num_channels = ARRAY_SIZE(hp03_channels);
> + indio_dev->info = &hp03_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + /*
> + * Allocate another device for the on-sensor EEPROM,
> + * which has it's dedicated I2C address and contains
> + * the calibration constants for the sensor.
> + */
> + priv->eeprom_client = i2c_new_dummy(client->adapter, HP03_EEPROM_ADDR);
> + if (!priv->eeprom_client) {
> + dev_err(dev, "New EEPROM I2C device failed\n");
> + return -ENODEV;
> + }
> +
> + priv->eeprom_regmap = devm_regmap_init_i2c(priv->eeprom_client,
> + &hp03_regmap_config);
> + if (IS_ERR(priv->eeprom_regmap)) {
> + dev_err(dev, "Failed to allocate EEPROM regmap\n");
> + ret = PTR_ERR(priv->eeprom_regmap);
> + goto err;
> + }
> +
> + priv->xclr_gpio = devm_gpiod_get_index(dev, "xclr", 0, GPIOD_OUT_HIGH);
> + if (IS_ERR(priv->xclr_gpio)) {
> + dev_err(dev, "Failed to claim XCLR GPIO\n");
> + ret = PTR_ERR(priv->xclr_gpio);
> + goto err;
> + }
> +
> + ret = devm_iio_device_register(dev, indio_dev);
> + if (ret) {
> + dev_err(dev, "Failed to register IIO device\n");
> + goto err;
> + }
> +
> + i2c_set_clientdata(client, indio_dev);
> +
> + return 0;
> +
> +err:
> + i2c_unregister_device(priv->eeprom_client);
> + return ret;
> +}
> +
> +static int hp03_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> + struct hp03_priv *priv = iio_priv(indio_dev);
> +
> + i2c_unregister_device(priv->eeprom_client);
> +
> + return 0;
> +}
> +
> +static const struct i2c_device_id hp03_id[] = {
> + { "hp03", 0 },
> + { },
> +};
> +MODULE_DEVICE_TABLE(i2c, hp03_id);
> +
> +static struct i2c_driver hp03_driver = {
> + .driver = {
> + .name = "hp03",
> + },
> + .probe = hp03_probe,
> + .remove = hp03_remove,
> + .id_table = hp03_id,
> +};
> +module_i2c_driver(hp03_driver);
> +
> +MODULE_AUTHOR("Marek Vasut <marex@xxxxxxx>");
> +MODULE_DESCRIPTION("Driver for Hope RF HP03 pressure and temperature sensor");
> +MODULE_LICENSE("GPL v2");
>
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