iio: humidity: add support to hts221 rh/temp combo device
authorLorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Thu, 13 Oct 2016 20:06:04 +0000 (22:06 +0200)
committerJonathan Cameron <jic23@kernel.org>
Sun, 23 Oct 2016 18:34:09 +0000 (19:34 +0100)
Add support to STM HTS221 humidity + temperature sensor

http://www.st.com/resource/en/datasheet/hts221.pdf

- continuous mode support
- i2c support
- spi support
- trigger mode support

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
drivers/iio/humidity/Kconfig
drivers/iio/humidity/Makefile
drivers/iio/humidity/hts221.h [new file with mode: 0644]
drivers/iio/humidity/hts221_buffer.c [new file with mode: 0644]
drivers/iio/humidity/hts221_core.c [new file with mode: 0644]
drivers/iio/humidity/hts221_i2c.c [new file with mode: 0644]
drivers/iio/humidity/hts221_spi.c [new file with mode: 0644]

index b17e2e2bd4f50736056fbbd3dfa56eafb3308499..6fd11d0813ad6d77bafa5dc3e2b89b67956c4171 100644 (file)
@@ -34,6 +34,28 @@ config HDC100X
          To compile this driver as a module, choose M here: the module
          will be called hdc100x.
 
+config HTS221
+       tristate "STMicroelectronics HTS221 sensor Driver"
+       depends on (I2C || SPI)
+       select IIO_BUFFER
+       select IIO_TRIGGERED_BUFFER
+       select HTS221_I2C if (I2C)
+       select HTS221_SPI if (SPI_MASTER)
+       help
+         Say yes here to build support for STMicroelectronics HTS221
+         temperature-humidity sensor
+
+         To compile this driver as a module, choose M here: the module
+         will be called hts221.
+
+config HTS221_I2C
+       tristate
+       depends on HTS221
+
+config HTS221_SPI
+       tristate
+       depends on HTS221
+
 config HTU21
        tristate "Measurement Specialties HTU21 humidity & temperature sensor"
        depends on I2C
index 4a73442fcd9c03b87adb8101ee9752e0cdb538b2..a6850e47c100981264081310855e5e061620728e 100644 (file)
@@ -5,6 +5,13 @@
 obj-$(CONFIG_AM2315) += am2315.o
 obj-$(CONFIG_DHT11) += dht11.o
 obj-$(CONFIG_HDC100X) += hdc100x.o
+
+hts221-y := hts221_core.o \
+           hts221_buffer.o
+obj-$(CONFIG_HTS221) += hts221.o
+obj-$(CONFIG_HTS221_I2C) += hts221_i2c.o
+obj-$(CONFIG_HTS221_SPI) += hts221_spi.o
+
 obj-$(CONFIG_HTU21) += htu21.o
 obj-$(CONFIG_SI7005) += si7005.o
 obj-$(CONFIG_SI7020) += si7020.o
diff --git a/drivers/iio/humidity/hts221.h b/drivers/iio/humidity/hts221.h
new file mode 100644 (file)
index 0000000..c715466
--- /dev/null
@@ -0,0 +1,73 @@
+/*
+ * STMicroelectronics hts221 sensor driver
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef HTS221_H
+#define HTS221_H
+
+#define HTS221_DEV_NAME                "hts221"
+
+#include <linux/iio/iio.h>
+
+#define HTS221_RX_MAX_LENGTH   8
+#define HTS221_TX_MAX_LENGTH   8
+
+#define HTS221_DATA_SIZE       2
+
+struct hts221_transfer_buffer {
+       u8 rx_buf[HTS221_RX_MAX_LENGTH];
+       u8 tx_buf[HTS221_TX_MAX_LENGTH] ____cacheline_aligned;
+};
+
+struct hts221_transfer_function {
+       int (*read)(struct device *dev, u8 addr, int len, u8 *data);
+       int (*write)(struct device *dev, u8 addr, int len, u8 *data);
+};
+
+#define HTS221_AVG_DEPTH       8
+struct hts221_avg_avl {
+       u16 avg;
+       u8 val;
+};
+
+enum hts221_sensor_type {
+       HTS221_SENSOR_H,
+       HTS221_SENSOR_T,
+       HTS221_SENSOR_MAX,
+};
+
+struct hts221_sensor {
+       u8 cur_avg_idx;
+       int slope, b_gen;
+};
+
+struct hts221_hw {
+       const char *name;
+       struct device *dev;
+
+       struct mutex lock;
+       struct iio_trigger *trig;
+       int irq;
+
+       struct hts221_sensor sensors[HTS221_SENSOR_MAX];
+
+       u8 odr;
+
+       const struct hts221_transfer_function *tf;
+       struct hts221_transfer_buffer tb;
+};
+
+int hts221_config_drdy(struct hts221_hw *hw, bool enable);
+int hts221_probe(struct iio_dev *iio_dev);
+int hts221_power_on(struct hts221_hw *hw);
+int hts221_power_off(struct hts221_hw *hw);
+int hts221_allocate_buffers(struct hts221_hw *hw);
+int hts221_allocate_trigger(struct hts221_hw *hw);
+
+#endif /* HTS221_H */
diff --git a/drivers/iio/humidity/hts221_buffer.c b/drivers/iio/humidity/hts221_buffer.c
new file mode 100644 (file)
index 0000000..76b2e81
--- /dev/null
@@ -0,0 +1,169 @@
+/*
+ * STMicroelectronics hts221 sensor driver
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/irqreturn.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/interrupt.h>
+#include <linux/iio/events.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/buffer.h>
+
+#include "hts221.h"
+
+#define HTS221_REG_STATUS_ADDR         0x27
+#define HTS221_RH_DRDY_MASK            BIT(1)
+#define HTS221_TEMP_DRDY_MASK          BIT(0)
+
+static int hts221_trig_set_state(struct iio_trigger *trig, bool state)
+{
+       struct iio_dev *iio_dev = iio_trigger_get_drvdata(trig);
+       struct hts221_hw *hw = iio_priv(iio_dev);
+
+       return hts221_config_drdy(hw, state);
+}
+
+static const struct iio_trigger_ops hts221_trigger_ops = {
+       .owner = THIS_MODULE,
+       .set_trigger_state = hts221_trig_set_state,
+};
+
+static irqreturn_t hts221_trigger_handler_thread(int irq, void *private)
+{
+       struct hts221_hw *hw = (struct hts221_hw *)private;
+       u8 status;
+       int err;
+
+       err = hw->tf->read(hw->dev, HTS221_REG_STATUS_ADDR, sizeof(status),
+                          &status);
+       if (err < 0)
+               return IRQ_HANDLED;
+
+       /* 
+        * H_DA bit (humidity data available) is routed to DRDY line.
+        * Humidity sample is computed after temperature one.
+        * Here we can assume data channels are both available if H_DA bit
+        * is set in status register
+        */
+       if (!(status & HTS221_RH_DRDY_MASK))
+               return IRQ_NONE;
+
+       iio_trigger_poll_chained(hw->trig);
+
+       return IRQ_HANDLED;
+}
+
+int hts221_allocate_trigger(struct hts221_hw *hw)
+{
+       struct iio_dev *iio_dev = iio_priv_to_dev(hw);
+       unsigned long irq_type;
+       int err;
+
+       irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));
+
+       switch (irq_type) {
+       case IRQF_TRIGGER_HIGH:
+       case IRQF_TRIGGER_RISING:
+               break;
+       default:
+               dev_info(hw->dev,
+                        "mode %lx unsupported, using IRQF_TRIGGER_RISING\n",
+                        irq_type);
+               irq_type = IRQF_TRIGGER_RISING;
+               break;
+       }
+
+       err = devm_request_threaded_irq(hw->dev, hw->irq, NULL,
+                                       hts221_trigger_handler_thread,
+                                       irq_type | IRQF_ONESHOT,
+                                       hw->name, hw);
+       if (err) {
+               dev_err(hw->dev, "failed to request trigger irq %d\n",
+                       hw->irq);
+               return err;
+       }
+
+       hw->trig = devm_iio_trigger_alloc(hw->dev, "%s-trigger",
+                                         iio_dev->name);
+       if (!hw->trig)
+               return -ENOMEM;
+
+       iio_trigger_set_drvdata(hw->trig, iio_dev);
+       hw->trig->ops = &hts221_trigger_ops;
+       hw->trig->dev.parent = hw->dev;
+       iio_dev->trig = iio_trigger_get(hw->trig);
+
+       return devm_iio_trigger_register(hw->dev, hw->trig);
+}
+
+static int hts221_buffer_preenable(struct iio_dev *iio_dev)
+{
+       return hts221_power_on(iio_priv(iio_dev));
+}
+
+static int hts221_buffer_postdisable(struct iio_dev *iio_dev)
+{
+       return hts221_power_off(iio_priv(iio_dev));
+}
+
+static const struct iio_buffer_setup_ops hts221_buffer_ops = {
+       .preenable = hts221_buffer_preenable,
+       .postenable = iio_triggered_buffer_postenable,
+       .predisable = iio_triggered_buffer_predisable,
+       .postdisable = hts221_buffer_postdisable,
+};
+
+static irqreturn_t hts221_buffer_handler_thread(int irq, void *p)
+{
+       u8 buffer[ALIGN(2 * HTS221_DATA_SIZE, sizeof(s64)) + sizeof(s64)];
+       struct iio_poll_func *pf = p;
+       struct iio_dev *iio_dev = pf->indio_dev;
+       struct hts221_hw *hw = iio_priv(iio_dev);
+       struct iio_chan_spec const *ch;
+       int err;
+
+       /* humidity data */
+       ch = &iio_dev->channels[HTS221_SENSOR_H];
+       err = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
+                          buffer);
+       if (err < 0)
+               goto out;
+
+       /* temperature data */
+       ch = &iio_dev->channels[HTS221_SENSOR_T];
+       err = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
+                          buffer + HTS221_DATA_SIZE);
+       if (err < 0)
+               goto out;
+
+       iio_push_to_buffers_with_timestamp(iio_dev, buffer,
+                                          iio_get_time_ns(iio_dev));
+
+out:
+       iio_trigger_notify_done(hw->trig);
+
+       return IRQ_HANDLED;
+}
+
+int hts221_allocate_buffers(struct hts221_hw *hw)
+{
+       return devm_iio_triggered_buffer_setup(hw->dev, iio_priv_to_dev(hw),
+                                       NULL, hts221_buffer_handler_thread,
+                                       &hts221_buffer_ops);
+}
+
+MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics hts221 buffer driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/humidity/hts221_core.c b/drivers/iio/humidity/hts221_core.c
new file mode 100644 (file)
index 0000000..3f3ef4a
--- /dev/null
@@ -0,0 +1,687 @@
+/*
+ * STMicroelectronics hts221 sensor driver
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/iio/sysfs.h>
+#include <linux/delay.h>
+#include <asm/unaligned.h>
+
+#include "hts221.h"
+
+#define HTS221_REG_WHOAMI_ADDR         0x0f
+#define HTS221_REG_WHOAMI_VAL          0xbc
+
+#define HTS221_REG_CNTRL1_ADDR         0x20
+#define HTS221_REG_CNTRL2_ADDR         0x21
+#define HTS221_REG_CNTRL3_ADDR         0x22
+
+#define HTS221_REG_AVG_ADDR            0x10
+#define HTS221_REG_H_OUT_L             0x28
+#define HTS221_REG_T_OUT_L             0x2a
+
+#define HTS221_HUMIDITY_AVG_MASK       0x07
+#define HTS221_TEMP_AVG_MASK           0x38
+
+#define HTS221_ODR_MASK                        0x87
+#define HTS221_BDU_MASK                        BIT(2)
+
+#define HTS221_DRDY_MASK               BIT(2)
+
+#define HTS221_ENABLE_SENSOR           BIT(7)
+
+#define HTS221_HUMIDITY_AVG_4          0x00 /* 0.4 %RH */
+#define HTS221_HUMIDITY_AVG_8          0x01 /* 0.3 %RH */
+#define HTS221_HUMIDITY_AVG_16         0x02 /* 0.2 %RH */
+#define HTS221_HUMIDITY_AVG_32         0x03 /* 0.15 %RH */
+#define HTS221_HUMIDITY_AVG_64         0x04 /* 0.1 %RH */
+#define HTS221_HUMIDITY_AVG_128                0x05 /* 0.07 %RH */
+#define HTS221_HUMIDITY_AVG_256                0x06 /* 0.05 %RH */
+#define HTS221_HUMIDITY_AVG_512                0x07 /* 0.03 %RH */
+
+#define HTS221_TEMP_AVG_2              0x00 /* 0.08 degC */
+#define HTS221_TEMP_AVG_4              0x08 /* 0.05 degC */
+#define HTS221_TEMP_AVG_8              0x10 /* 0.04 degC */
+#define HTS221_TEMP_AVG_16             0x18 /* 0.03 degC */
+#define HTS221_TEMP_AVG_32             0x20 /* 0.02 degC */
+#define HTS221_TEMP_AVG_64             0x28 /* 0.015 degC */
+#define HTS221_TEMP_AVG_128            0x30 /* 0.01 degC */
+#define HTS221_TEMP_AVG_256            0x38 /* 0.007 degC */
+
+/* calibration registers */
+#define HTS221_REG_0RH_CAL_X_H         0x36
+#define HTS221_REG_1RH_CAL_X_H         0x3a
+#define HTS221_REG_0RH_CAL_Y_H         0x30
+#define HTS221_REG_1RH_CAL_Y_H         0x31
+#define HTS221_REG_0T_CAL_X_L          0x3c
+#define HTS221_REG_1T_CAL_X_L          0x3e
+#define HTS221_REG_0T_CAL_Y_H          0x32
+#define HTS221_REG_1T_CAL_Y_H          0x33
+#define HTS221_REG_T1_T0_CAL_Y_H       0x35
+
+struct hts221_odr {
+       u8 hz;
+       u8 val;
+};
+
+struct hts221_avg {
+       u8 addr;
+       u8 mask;
+       struct hts221_avg_avl avg_avl[HTS221_AVG_DEPTH];
+};
+
+static const struct hts221_odr hts221_odr_table[] = {
+       {  1, 0x01 },   /* 1Hz */
+       {  7, 0x02 },   /* 7Hz */
+       { 13, 0x03 },   /* 12.5Hz */
+};
+
+static const struct hts221_avg hts221_avg_list[] = {
+       {
+               .addr = HTS221_REG_AVG_ADDR,
+               .mask = HTS221_HUMIDITY_AVG_MASK,
+               .avg_avl = {
+                       { 4, HTS221_HUMIDITY_AVG_4 },
+                       { 8, HTS221_HUMIDITY_AVG_8 },
+                       { 16, HTS221_HUMIDITY_AVG_16 },
+                       { 32, HTS221_HUMIDITY_AVG_32 },
+                       { 64, HTS221_HUMIDITY_AVG_64 },
+                       { 128, HTS221_HUMIDITY_AVG_128 },
+                       { 256, HTS221_HUMIDITY_AVG_256 },
+                       { 512, HTS221_HUMIDITY_AVG_512 },
+               },
+       },
+       {
+               .addr = HTS221_REG_AVG_ADDR,
+               .mask = HTS221_TEMP_AVG_MASK,
+               .avg_avl = {
+                       { 2, HTS221_TEMP_AVG_2 },
+                       { 4, HTS221_TEMP_AVG_4 },
+                       { 8, HTS221_TEMP_AVG_8 },
+                       { 16, HTS221_TEMP_AVG_16 },
+                       { 32, HTS221_TEMP_AVG_32 },
+                       { 64, HTS221_TEMP_AVG_64 },
+                       { 128, HTS221_TEMP_AVG_128 },
+                       { 256, HTS221_TEMP_AVG_256 },
+               },
+       },
+};
+
+static const struct iio_chan_spec hts221_channels[] = {
+       {
+               .type = IIO_HUMIDITYRELATIVE,
+               .address = HTS221_REG_H_OUT_L,
+               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+                                     BIT(IIO_CHAN_INFO_OFFSET) |
+                                     BIT(IIO_CHAN_INFO_SCALE) |
+                                     BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+               .scan_index = 0,
+               .scan_type = {
+                       .sign = 's',
+                       .realbits = 16,
+                       .storagebits = 16,
+                       .endianness = IIO_LE,
+               },
+       },
+       {
+               .type = IIO_TEMP,
+               .address = HTS221_REG_T_OUT_L,
+               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+                                     BIT(IIO_CHAN_INFO_OFFSET) |
+                                     BIT(IIO_CHAN_INFO_SCALE) |
+                                     BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+               .scan_index = 1,
+               .scan_type = {
+                       .sign = 's',
+                       .realbits = 16,
+                       .storagebits = 16,
+                       .endianness = IIO_LE,
+               },
+       },
+       IIO_CHAN_SOFT_TIMESTAMP(2),
+};
+
+static int hts221_write_with_mask(struct hts221_hw *hw, u8 addr, u8 mask,
+                                 u8 val)
+{
+       u8 data;
+       int err;
+
+       mutex_lock(&hw->lock);
+
+       err = hw->tf->read(hw->dev, addr, sizeof(data), &data);
+       if (err < 0) {
+               dev_err(hw->dev, "failed to read %02x register\n", addr);
+               goto unlock;
+       }
+
+       data = (data & ~mask) | (val & mask);
+
+       err = hw->tf->write(hw->dev, addr, sizeof(data), &data);
+       if (err < 0)
+               dev_err(hw->dev, "failed to write %02x register\n", addr);
+
+unlock:
+       mutex_unlock(&hw->lock);
+
+       return err;
+}
+
+static int hts221_check_whoami(struct hts221_hw *hw)
+{
+       u8 data;
+       int err;
+
+       err = hw->tf->read(hw->dev, HTS221_REG_WHOAMI_ADDR, sizeof(data),
+                          &data);
+       if (err < 0) {
+               dev_err(hw->dev, "failed to read whoami register\n");
+               return err;
+       }
+
+       if (data != HTS221_REG_WHOAMI_VAL) {
+               dev_err(hw->dev, "wrong whoami {%02x vs %02x}\n",
+                       data, HTS221_REG_WHOAMI_VAL);
+               return -ENODEV;
+       }
+
+       return 0;
+}
+
+int hts221_config_drdy(struct hts221_hw *hw, bool enable)
+{
+       u8 val = enable ? BIT(2) : 0;
+       int err;
+
+       err = hts221_write_with_mask(hw, HTS221_REG_CNTRL3_ADDR,
+                                    HTS221_DRDY_MASK, val);
+
+       return err < 0 ? err : 0;
+}
+
+static int hts221_update_odr(struct hts221_hw *hw, u8 odr)
+{
+       int i, err;
+       u8 val;
+
+       for (i = 0; i < ARRAY_SIZE(hts221_odr_table); i++)
+               if (hts221_odr_table[i].hz == odr)
+                       break;
+
+       if (i == ARRAY_SIZE(hts221_odr_table))
+               return -EINVAL;
+
+       val = HTS221_ENABLE_SENSOR | HTS221_BDU_MASK | hts221_odr_table[i].val;
+       err = hts221_write_with_mask(hw, HTS221_REG_CNTRL1_ADDR,
+                                    HTS221_ODR_MASK, val);
+       if (err < 0)
+               return err;
+
+       hw->odr = odr;
+
+       return 0;
+}
+
+static int hts221_update_avg(struct hts221_hw *hw,
+                            enum hts221_sensor_type type,
+                            u16 val)
+{
+       int i, err;
+       const struct hts221_avg *avg = &hts221_avg_list[type];
+
+       for (i = 0; i < HTS221_AVG_DEPTH; i++)
+               if (avg->avg_avl[i].avg == val)
+                       break;
+
+       if (i == HTS221_AVG_DEPTH)
+               return -EINVAL;
+
+       err = hts221_write_with_mask(hw, avg->addr, avg->mask,
+                                    avg->avg_avl[i].val);
+       if (err < 0)
+               return err;
+
+       hw->sensors[type].cur_avg_idx = i;
+
+       return 0;
+}
+
+static ssize_t hts221_sysfs_sampling_freq(struct device *dev,
+                                         struct device_attribute *attr,
+                                         char *buf)
+{
+       int i;
+       ssize_t len = 0;
+
+       for (i = 0; i < ARRAY_SIZE(hts221_odr_table); i++)
+               len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
+                                hts221_odr_table[i].hz);
+       buf[len - 1] = '\n';
+
+       return len;
+}
+
+static ssize_t
+hts221_sysfs_rh_oversampling_avail(struct device *dev,
+                                  struct device_attribute *attr,
+                                  char *buf)
+{
+       const struct hts221_avg *avg = &hts221_avg_list[HTS221_SENSOR_H];
+       ssize_t len = 0;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(avg->avg_avl); i++)
+               len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
+                                avg->avg_avl[i].avg);
+       buf[len - 1] = '\n';
+
+       return len;
+}
+
+static ssize_t
+hts221_sysfs_temp_oversampling_avail(struct device *dev,
+                                    struct device_attribute *attr,
+                                    char *buf)
+{
+       const struct hts221_avg *avg = &hts221_avg_list[HTS221_SENSOR_T];
+       ssize_t len = 0;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(avg->avg_avl); i++)
+               len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
+                                avg->avg_avl[i].avg);
+       buf[len - 1] = '\n';
+
+       return len;
+}
+
+int hts221_power_on(struct hts221_hw *hw)
+{
+       return hts221_update_odr(hw, hw->odr);
+}
+
+int hts221_power_off(struct hts221_hw *hw)
+{
+       u8 data[] = {0x00, 0x00};
+
+       return hw->tf->write(hw->dev, HTS221_REG_CNTRL1_ADDR, sizeof(data),
+                            data);
+}
+
+static int hts221_parse_temp_caldata(struct hts221_hw *hw)
+{
+       int err, *slope, *b_gen;
+       s16 cal_x0, cal_x1, cal_y0, cal_y1;
+       u8 cal0, cal1;
+
+       err = hw->tf->read(hw->dev, HTS221_REG_0T_CAL_Y_H,
+                          sizeof(cal0), &cal0);
+       if (err < 0)
+               return err;
+
+       err = hw->tf->read(hw->dev, HTS221_REG_T1_T0_CAL_Y_H,
+                          sizeof(cal1), &cal1);
+       if (err < 0)
+               return err;
+       cal_y0 = (le16_to_cpu(cal1 & 0x3) << 8) | cal0;
+
+       err = hw->tf->read(hw->dev, HTS221_REG_1T_CAL_Y_H,
+                          sizeof(cal0), &cal0);
+       if (err < 0)
+               return err;
+       cal_y1 = (((cal1 & 0xc) >> 2) << 8) | cal0;
+
+       err = hw->tf->read(hw->dev, HTS221_REG_0T_CAL_X_L, sizeof(cal_x0),
+                          (u8 *)&cal_x0);
+       if (err < 0)
+               return err;
+       cal_x0 = le16_to_cpu(cal_x0);
+
+       err = hw->tf->read(hw->dev, HTS221_REG_1T_CAL_X_L, sizeof(cal_x1),
+                          (u8 *)&cal_x1);
+       if (err < 0)
+               return err;
+       cal_x1 = le16_to_cpu(cal_x1);
+
+       slope = &hw->sensors[HTS221_SENSOR_T].slope;
+       b_gen = &hw->sensors[HTS221_SENSOR_T].b_gen;
+
+       *slope = ((cal_y1 - cal_y0) * 8000) / (cal_x1 - cal_x0);
+       *b_gen = (((s32)cal_x1 * cal_y0 - (s32)cal_x0 * cal_y1) * 1000) /
+                (cal_x1 - cal_x0);
+       *b_gen *= 8;
+
+       return 0;
+}
+
+static int hts221_parse_rh_caldata(struct hts221_hw *hw)
+{
+       int err, *slope, *b_gen;
+       s16 cal_x0, cal_x1, cal_y0, cal_y1;
+       u8 data;
+
+       err = hw->tf->read(hw->dev, HTS221_REG_0RH_CAL_Y_H, sizeof(data),
+                          &data);
+       if (err < 0)
+               return err;
+       cal_y0 = data;
+
+       err = hw->tf->read(hw->dev, HTS221_REG_1RH_CAL_Y_H, sizeof(data),
+                          &data);
+       if (err < 0)
+               return err;
+       cal_y1 = data;
+
+       err = hw->tf->read(hw->dev, HTS221_REG_0RH_CAL_X_H, sizeof(cal_x0),
+                          (u8 *)&cal_x0);
+       if (err < 0)
+               return err;
+       cal_x0 = le16_to_cpu(cal_x0);
+
+       err = hw->tf->read(hw->dev, HTS221_REG_1RH_CAL_X_H, sizeof(cal_x1),
+                          (u8 *)&cal_x1);
+       if (err < 0)
+               return err;
+       cal_x1 = le16_to_cpu(cal_x1);
+
+       slope = &hw->sensors[HTS221_SENSOR_H].slope;
+       b_gen = &hw->sensors[HTS221_SENSOR_H].b_gen;
+
+       *slope = ((cal_y1 - cal_y0) * 8000) / (cal_x1 - cal_x0);
+       *b_gen = (((s32)cal_x1 * cal_y0 - (s32)cal_x0 * cal_y1) * 1000) /
+                (cal_x1 - cal_x0);
+       *b_gen *= 8;
+
+       return 0;
+}
+
+static int hts221_get_sensor_scale(struct hts221_hw *hw,
+                                  enum iio_chan_type ch_type,
+                                  int *val, int *val2)
+{
+       s64 tmp;
+       s32 rem, div, data;
+
+       switch (ch_type) {
+       case IIO_HUMIDITYRELATIVE:
+               data = hw->sensors[HTS221_SENSOR_H].slope;
+               div = (1 << 4) * 1000;
+               break;
+       case IIO_TEMP:
+               data = hw->sensors[HTS221_SENSOR_T].slope;
+               div = (1 << 6) * 1000;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       tmp = div_s64(data * 1000000000LL, div);
+       tmp = div_s64_rem(tmp, 1000000000LL, &rem);
+
+       *val = tmp;
+       *val2 = rem;
+
+       return IIO_VAL_INT_PLUS_NANO;
+}
+
+static int hts221_get_sensor_offset(struct hts221_hw *hw,
+                                   enum iio_chan_type ch_type,
+                                   int *val, int *val2)
+{
+       s64 tmp;
+       s32 rem, div, data;
+
+       switch (ch_type) {
+       case IIO_HUMIDITYRELATIVE:
+               data = hw->sensors[HTS221_SENSOR_H].b_gen;
+               div = hw->sensors[HTS221_SENSOR_H].slope;
+               break;
+       case IIO_TEMP:
+               data = hw->sensors[HTS221_SENSOR_T].b_gen;
+               div = hw->sensors[HTS221_SENSOR_T].slope;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       tmp = div_s64(data * 1000000000LL, div);
+       tmp = div_s64_rem(tmp, 1000000000LL, &rem);
+
+       *val = tmp;
+       *val2 = rem;
+
+       return IIO_VAL_INT_PLUS_NANO;
+}
+
+static int hts221_read_oneshot(struct hts221_hw *hw, u8 addr, int *val)
+{
+       u8 data[HTS221_DATA_SIZE];
+       int err;
+
+       err = hts221_power_on(hw);
+       if (err < 0)
+               return err;
+
+       msleep(50);
+
+       err = hw->tf->read(hw->dev, addr, sizeof(data), data);
+       if (err < 0)
+               return err;
+
+       hts221_power_off(hw);
+
+       *val = (s16)get_unaligned_le16(data);
+
+       return IIO_VAL_INT;
+}
+
+static int hts221_read_raw(struct iio_dev *iio_dev,
+                          struct iio_chan_spec const *ch,
+                          int *val, int *val2, long mask)
+{
+       struct hts221_hw *hw = iio_priv(iio_dev);
+       int ret;
+
+       ret = iio_device_claim_direct_mode(iio_dev);
+       if (ret)
+               return ret;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_RAW:
+               ret = hts221_read_oneshot(hw, ch->address, val);
+               break;
+       case IIO_CHAN_INFO_SCALE:
+               ret = hts221_get_sensor_scale(hw, ch->type, val, val2);
+               break;
+       case IIO_CHAN_INFO_OFFSET:
+               ret = hts221_get_sensor_offset(hw, ch->type, val, val2);
+               break;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               *val = hw->odr;
+               ret = IIO_VAL_INT;
+               break;
+       case IIO_CHAN_INFO_OVERSAMPLING_RATIO: {
+               u8 idx;
+               const struct hts221_avg *avg;
+
+               switch (ch->type) {
+               case IIO_HUMIDITYRELATIVE:
+                       avg = &hts221_avg_list[HTS221_SENSOR_H];
+                       idx = hw->sensors[HTS221_SENSOR_H].cur_avg_idx;
+                       *val = avg->avg_avl[idx].avg;
+                       ret = IIO_VAL_INT;
+                       break;
+               case IIO_TEMP:
+                       avg = &hts221_avg_list[HTS221_SENSOR_T];
+                       idx = hw->sensors[HTS221_SENSOR_T].cur_avg_idx;
+                       *val = avg->avg_avl[idx].avg;
+                       ret = IIO_VAL_INT;
+                       break;
+               default:
+                       ret = -EINVAL;
+                       break;
+               }
+               break;
+       }
+       default:
+               ret = -EINVAL;
+               break;
+       }
+
+       iio_device_release_direct_mode(iio_dev);
+
+       return ret;
+}
+
+static int hts221_write_raw(struct iio_dev *iio_dev,
+                           struct iio_chan_spec const *chan,
+                           int val, int val2, long mask)
+{
+       struct hts221_hw *hw = iio_priv(iio_dev);
+       int ret;
+
+       ret = iio_device_claim_direct_mode(iio_dev);
+       if (ret)
+               return ret;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               ret = hts221_update_odr(hw, val);
+               break;
+       case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+               switch (chan->type) {
+               case IIO_HUMIDITYRELATIVE:
+                       ret = hts221_update_avg(hw, HTS221_SENSOR_H, val);
+                       break;
+               case IIO_TEMP:
+                       ret = hts221_update_avg(hw, HTS221_SENSOR_T, val);
+                       break;
+               default:
+                       ret = -EINVAL;
+                       break;
+               }
+               break;
+       default:
+               ret = -EINVAL;
+               break;
+       }
+
+       iio_device_release_direct_mode(iio_dev);
+
+       return ret;
+}
+
+static int hts221_validate_trigger(struct iio_dev *iio_dev,
+                                  struct iio_trigger *trig)
+{
+       struct hts221_hw *hw = iio_priv(iio_dev);
+
+       return hw->trig == trig ? 0 : -EINVAL;
+}
+
+static IIO_DEVICE_ATTR(in_humidity_oversampling_ratio_available, S_IRUGO,
+                      hts221_sysfs_rh_oversampling_avail, NULL, 0);
+static IIO_DEVICE_ATTR(in_temp_oversampling_ratio_available, S_IRUGO,
+                      hts221_sysfs_temp_oversampling_avail, NULL, 0);
+static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(hts221_sysfs_sampling_freq);
+
+static struct attribute *hts221_attributes[] = {
+       &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+       &iio_dev_attr_in_humidity_oversampling_ratio_available.dev_attr.attr,
+       &iio_dev_attr_in_temp_oversampling_ratio_available.dev_attr.attr,
+       NULL,
+};
+
+static const struct attribute_group hts221_attribute_group = {
+       .attrs = hts221_attributes,
+};
+
+static const struct iio_info hts221_info = {
+       .driver_module = THIS_MODULE,
+       .attrs = &hts221_attribute_group,
+       .read_raw = hts221_read_raw,
+       .write_raw = hts221_write_raw,
+       .validate_trigger = hts221_validate_trigger,
+};
+
+static const unsigned long hts221_scan_masks[] = {0x3, 0x0};
+
+int hts221_probe(struct iio_dev *iio_dev)
+{
+       struct hts221_hw *hw = iio_priv(iio_dev);
+       int err;
+       u8 data;
+
+       mutex_init(&hw->lock);
+
+       err = hts221_check_whoami(hw);
+       if (err < 0)
+               return err;
+
+       hw->odr = hts221_odr_table[0].hz;
+
+       iio_dev->modes = INDIO_DIRECT_MODE;
+       iio_dev->dev.parent = hw->dev;
+       iio_dev->available_scan_masks = hts221_scan_masks;
+       iio_dev->channels = hts221_channels;
+       iio_dev->num_channels = ARRAY_SIZE(hts221_channels);
+       iio_dev->name = HTS221_DEV_NAME;
+       iio_dev->info = &hts221_info;
+
+       /* configure humidity sensor */
+       err = hts221_parse_rh_caldata(hw);
+       if (err < 0) {
+               dev_err(hw->dev, "failed to get rh calibration data\n");
+               return err;
+       }
+
+       data = hts221_avg_list[HTS221_SENSOR_H].avg_avl[3].avg;
+       err = hts221_update_avg(hw, HTS221_SENSOR_H, data);
+       if (err < 0) {
+               dev_err(hw->dev, "failed to set rh oversampling ratio\n");
+               return err;
+       }
+
+       /* configure temperature sensor */
+       err = hts221_parse_temp_caldata(hw);
+       if (err < 0) {
+               dev_err(hw->dev,
+                       "failed to get temperature calibration data\n");
+               return err;
+       }
+
+       data = hts221_avg_list[HTS221_SENSOR_T].avg_avl[3].avg;
+       err = hts221_update_avg(hw, HTS221_SENSOR_T, data);
+       if (err < 0) {
+               dev_err(hw->dev,
+                       "failed to set temperature oversampling ratio\n");
+               return err;
+       }
+
+       if (hw->irq > 0) {
+               err = hts221_allocate_buffers(hw);
+               if (err < 0)
+                       return err;
+
+               err = hts221_allocate_trigger(hw);
+               if (err)
+                       return err;
+       }
+
+       return devm_iio_device_register(hw->dev, iio_dev);
+}
+EXPORT_SYMBOL(hts221_probe);
+
+MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics hts221 sensor driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/humidity/hts221_i2c.c b/drivers/iio/humidity/hts221_i2c.c
new file mode 100644 (file)
index 0000000..367ecd5
--- /dev/null
@@ -0,0 +1,110 @@
+/*
+ * STMicroelectronics hts221 i2c driver
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include "hts221.h"
+
+#define I2C_AUTO_INCREMENT     0x80
+
+static int hts221_i2c_read(struct device *dev, u8 addr, int len, u8 *data)
+{
+       struct i2c_msg msg[2];
+       struct i2c_client *client = to_i2c_client(dev);
+
+       if (len > 1)
+               addr |= I2C_AUTO_INCREMENT;
+
+       msg[0].addr = client->addr;
+       msg[0].flags = client->flags;
+       msg[0].len = 1;
+       msg[0].buf = &addr;
+
+       msg[1].addr = client->addr;
+       msg[1].flags = client->flags | I2C_M_RD;
+       msg[1].len = len;
+       msg[1].buf = data;
+
+       return i2c_transfer(client->adapter, msg, 2);
+}
+
+static int hts221_i2c_write(struct device *dev, u8 addr, int len, u8 *data)
+{
+       u8 send[len + 1];
+       struct i2c_msg msg;
+       struct i2c_client *client = to_i2c_client(dev);
+
+       if (len > 1)
+               addr |= I2C_AUTO_INCREMENT;
+
+       send[0] = addr;
+       memcpy(&send[1], data, len * sizeof(u8));
+
+       msg.addr = client->addr;
+       msg.flags = client->flags;
+       msg.len = len + 1;
+       msg.buf = send;
+
+       return i2c_transfer(client->adapter, &msg, 1);
+}
+
+static const struct hts221_transfer_function hts221_transfer_fn = {
+       .read = hts221_i2c_read,
+       .write = hts221_i2c_write,
+};
+
+static int hts221_i2c_probe(struct i2c_client *client,
+                           const struct i2c_device_id *id)
+{
+       struct hts221_hw *hw;
+       struct iio_dev *iio_dev;
+
+       iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*hw));
+       if (!iio_dev)
+               return -ENOMEM;
+
+       i2c_set_clientdata(client, iio_dev);
+
+       hw = iio_priv(iio_dev);
+       hw->name = client->name;
+       hw->dev = &client->dev;
+       hw->irq = client->irq;
+       hw->tf = &hts221_transfer_fn;
+
+       return hts221_probe(iio_dev);
+}
+
+static const struct of_device_id hts221_i2c_of_match[] = {
+       { .compatible = "st,hts221", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, hts221_i2c_of_match);
+
+static const struct i2c_device_id hts221_i2c_id_table[] = {
+       { HTS221_DEV_NAME },
+       {},
+};
+MODULE_DEVICE_TABLE(i2c, hts221_i2c_id_table);
+
+static struct i2c_driver hts221_driver = {
+       .driver = {
+               .name = "hts221_i2c",
+               .of_match_table = of_match_ptr(hts221_i2c_of_match),
+       },
+       .probe = hts221_i2c_probe,
+       .id_table = hts221_i2c_id_table,
+};
+module_i2c_driver(hts221_driver);
+
+MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics hts221 i2c driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/humidity/hts221_spi.c b/drivers/iio/humidity/hts221_spi.c
new file mode 100644 (file)
index 0000000..70df5e7
--- /dev/null
@@ -0,0 +1,125 @@
+/*
+ * STMicroelectronics hts221 spi driver
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi@st.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include "hts221.h"
+
+#define SENSORS_SPI_READ       0x80
+#define SPI_AUTO_INCREMENT     0x40
+
+static int hts221_spi_read(struct device *dev, u8 addr, int len, u8 *data)
+{
+       int err;
+       struct spi_device *spi = to_spi_device(dev);
+       struct iio_dev *iio_dev = spi_get_drvdata(spi);
+       struct hts221_hw *hw = iio_priv(iio_dev);
+
+       struct spi_transfer xfers[] = {
+               {
+                       .tx_buf = hw->tb.tx_buf,
+                       .bits_per_word = 8,
+                       .len = 1,
+               },
+               {
+                       .rx_buf = hw->tb.rx_buf,
+                       .bits_per_word = 8,
+                       .len = len,
+               }
+       };
+
+       if (len > 1)
+               addr |= SPI_AUTO_INCREMENT;
+       hw->tb.tx_buf[0] = addr | SENSORS_SPI_READ;
+
+       err = spi_sync_transfer(spi, xfers,  ARRAY_SIZE(xfers));
+       if (err < 0)
+               return err;
+
+       memcpy(data, hw->tb.rx_buf, len * sizeof(u8));
+
+       return len;
+}
+
+static int hts221_spi_write(struct device *dev, u8 addr, int len, u8 *data)
+{
+       struct spi_device *spi = to_spi_device(dev);
+       struct iio_dev *iio_dev = spi_get_drvdata(spi);
+       struct hts221_hw *hw = iio_priv(iio_dev);
+
+       struct spi_transfer xfers = {
+               .tx_buf = hw->tb.tx_buf,
+               .bits_per_word = 8,
+               .len = len + 1,
+       };
+
+       if (len >= HTS221_TX_MAX_LENGTH)
+               return -ENOMEM;
+
+       if (len > 1)
+               addr |= SPI_AUTO_INCREMENT;
+       hw->tb.tx_buf[0] = addr;
+       memcpy(&hw->tb.tx_buf[1], data, len);
+
+       return spi_sync_transfer(spi, &xfers, 1);
+}
+
+static const struct hts221_transfer_function hts221_transfer_fn = {
+       .read = hts221_spi_read,
+       .write = hts221_spi_write,
+};
+
+static int hts221_spi_probe(struct spi_device *spi)
+{
+       struct hts221_hw *hw;
+       struct iio_dev *iio_dev;
+
+       iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*hw));
+       if (!iio_dev)
+               return -ENOMEM;
+
+       spi_set_drvdata(spi, iio_dev);
+
+       hw = iio_priv(iio_dev);
+       hw->name = spi->modalias;
+       hw->dev = &spi->dev;
+       hw->irq = spi->irq;
+       hw->tf = &hts221_transfer_fn;
+
+       return hts221_probe(iio_dev);
+}
+
+static const struct of_device_id hts221_spi_of_match[] = {
+       { .compatible = "st,hts221", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, hts221_spi_of_match);
+
+static const struct spi_device_id hts221_spi_id_table[] = {
+       { HTS221_DEV_NAME },
+       {},
+};
+MODULE_DEVICE_TABLE(spi, hts221_spi_id_table);
+
+static struct spi_driver hts221_driver = {
+       .driver = {
+               .name = "hts221_spi",
+               .of_match_table = of_match_ptr(hts221_spi_of_match),
+       },
+       .probe = hts221_spi_probe,
+       .id_table = hts221_spi_id_table,
+};
+module_spi_driver(hts221_driver);
+
+MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics hts221 spi driver");
+MODULE_LICENSE("GPL v2");