[PATCH] Add support for ads1110

[Duss Pirmin <pirmin.duss@flytec.ch>]

Hi

This patch adds support for the ads1110 adc from Texas Instruments.

This is my first submission to the Linux kernel.

Comments welcome


diff -Naur aaa/drivers/staging/iio/adc//ads1110.c 
bbb/drivers/staging/iio/adc//ads1110.c
--- aaa/drivers/staging/iio/adc//ads1110.c    1970-01-01 
01:00:00.000000000 +0100
+++ bbb/drivers/staging/iio/adc//ads1110.c    2011-12-15 
13:53:32.000000000 +0100
@@ -0,0 +1,521 @@
+/*
+ * Driver for Texas Instruments ads1110 ADC.
+ *
+ * Datashhet con be found on: http://www.ti.com/lit/ds/symlink/ads1110.pdf
+ *
+ * Copyright 2011 Flytec AG.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+
+/*
+ * ADS1110 definitions
+ */
+
+#define ADS1110_CONFIG_ST_NDRDY        (1 << 7)
+#define ADS1110_CONFIG_SC              (1 << 4)
+
+#define ADS1110_CONFIG_DR_240          (0 << 2)
+#define ADS1110_CONFIG_DR_60           (1 << 2)
+#define ADS1110_CONFIG_DR_30           (2 << 2)
+#define ADS1110_CONFIG_DR_15           (3 << 2)
+
+#define ADS1110_CONFIG_PGA_1           0
+#define ADS1110_CONFIG_PGA_2           1
+#define ADS1110_CONFIG_PGA_4           2
+#define ADS1110_CONFIG_PGA_8           3
+
+#define ADS1110_MAX_CONV_MODE          2
+#define ADS1110_MAX_DATA_RATE          4
+#define ADS1110_MAX_PGA                4
+
+/*
+ * struct ads1110_chip_info  - chip specifig information
+ */
+
+struct ads1110_chip_info {
+    struct i2c_client        *client;
+    struct iio_dev            *indio_dev;
+
+    char *conversion_mode;
+    char *data_rate;
+    char *gain;
+};
+
+struct ads1110_conversion_mode {
+  char *name;
+  u8 reg_cfg;
+};
+
+static struct ads1110_conversion_mode
+ads1110_conv_mode_table[ADS1110_MAX_CONV_MODE] = {
+  { "continuous-conversion", 0 },
+  { "single-conversion", 1 },
+};
+
+struct ads1110_data_rate {
+    char *name;
+    u8 reg_cfg;
+};
+
+static struct ads1110_data_rate
+ads1110_dr_table[ADS1110_MAX_DATA_RATE] = {
+  { "dr-15_SPS",  ADS1110_CONFIG_DR_15 },
+  { "dr-30_SPS",  ADS1110_CONFIG_DR_30 },
+  { "dr-60_SPS",  ADS1110_CONFIG_DR_60 },
+  { "dr-240_SPS", ADS1110_CONFIG_DR_240 },
+};
+
+struct ads1110_pga {
+    char *name;
+    u8 reg_cfg;
+};
+
+static struct ads1110_pga
+ads1110_pga_table[ADS1110_MAX_PGA] = {
+    { "gain-1",  ADS1110_CONFIG_PGA_1 },
+    { "gain-2",  ADS1110_CONFIG_PGA_2 },
+    { "gain-4",  ADS1110_CONFIG_PGA_4 },
+    { "gain-8",  ADS1110_CONFIG_PGA_8 },
+};
+
+/*
+ * cummunication functions for i2c
+ */
+
+static int ads1110_i2c_read_config(struct ads1110_chip_info *chip, u8 
*data)
+{
+    struct i2c_client *client = chip->client;
+    int ret = 0;
+    u8 tmp[3];        // read three bytes ; first two are data third is 
the config
+
+    ret = i2c_master_recv(client, tmp, 3);
+    if (ret < 3) {
+        dev_err(&client->dev, "I2C read error\n");
+        return ret;
+    }
+
+    *data = tmp[2];
+
+    return ret;
+}
+
+static int ads1110_i2c_read_data(struct ads1110_chip_info *chip, int *data)
+{
+    struct i2c_client *client = chip->client;
+    int ret = 0;
+    u8 tmp[3];        // read three bytes ; first two are data third is 
the config
+
+    ret = i2c_master_recv(client, tmp, 3);
+    if (ret < 3) {
+        dev_err(&client->dev, "I2C read error\n");
+        return ret;
+    }
+
+    *data = (int)(tmp[0] << 8) + tmp[1];
+
+    return ret;
+}
+
+
+static int ads1110_i2c_write_config(struct ads1110_chip_info *chip, u8 
data)
+{
+  struct i2c_client *client = chip->client;
+  int ret = 0;
+
+    ret = i2c_master_send(client, &data, 1);        // there is only 
one register to write to.
+    if (ret < 0)
+        dev_err(&client->dev, "I2C write error\n");
+
+    return ret;
+}
+
+/*
+ * sysfs nodes
+ */
+
+#define IIO_DEV_ATTR_AVAIL_CONVERSION_MODES(_show)        \
+    IIO_DEVICE_ATTR(available_conversion_modes, S_IRUGO, _show, NULL, 0)
+#define IIO_DEV_ATTR_AVAIL_DATA_RATES(_show)        \
+    IIO_DEVICE_ATTR(available_data_rates, S_IRUGO, _show, NULL, 0)
+#define IIO_DEV_ATTR_AVAIL_GAINS(_show)        \
+    IIO_DEVICE_ATTR(available_gains, S_IRUGO, _show, NULL, 0)
+#define IIO_DEV_ATTR_VALUE(_show)        \
+    IIO_DEVICE_ATTR(value, S_IRUGO, _show, NULL, 0)
+#define IIO_DEV_ATTR_CONVERSION_MODE(_mode, _show, _store)              \
+    IIO_DEVICE_ATTR(conversion_mode, _mode, _show, _store, 0)
+#define IIO_DEV_ATTR_DATA_RATE(_data_rate, _show, _store)              \
+    IIO_DEVICE_ATTR(data_rate, _data_rate, _show, _store, 0)
+#define IIO_DEV_ATTR_GAIN(_gain, _show, _store)              \
+    IIO_DEVICE_ATTR(gain, _gain, _show, _store, 0)
+#define IIO_DEV_ATTR_START_CONVERSION(_start_conversion, NULL, 
_store)              \
+    IIO_DEVICE_ATTR(start_conversion, _start_conversion, NULL, _store, 0)
+
+/*
+ * setter- / getter functions for the sysfs nodes.
+ */
+
+static ssize_t ads1110_show_conversion_modes(struct device *dev,
+    struct device_attribute *attr,
+    char *buf)
+{
+    int i;
+    int len = 0;
+
+    for (i = 0; i < ADS1110_MAX_CONV_MODE; i++)
+        len += sprintf(buf + len, "%s\n", ads1110_conv_mode_table[i].name);
+
+    return len;
+}
+
+static IIO_DEV_ATTR_AVAIL_CONVERSION_MODES(ads1110_show_conversion_modes);
+
+static ssize_t ads1110_show_data_rates(struct device *dev,
+    struct device_attribute *attr,
+    char *buf)
+{
+    int i;
+    int len = 0;
+
+    for (i = 0; i < ADS1110_MAX_DATA_RATE; i++)
+        len += sprintf(buf + len, "%s\n", ads1110_dr_table[i].name);
+
+    return len;
+}
+
+static IIO_DEV_ATTR_AVAIL_DATA_RATES(ads1110_show_data_rates);
+
+static ssize_t ads1110_show_gains(struct device *dev,
+    struct device_attribute *attr,
+    char *buf)
+{
+    int i;
+    int len = 0;
+
+    for (i = 0; i < ADS1110_MAX_PGA; i++)
+        len += sprintf(buf + len, "%s\n", ads1110_pga_table[i].name);
+
+    return len;
+}
+
+static IIO_DEV_ATTR_AVAIL_GAINS(ads1110_show_gains);
+
+static ssize_t ads1110_show_value(struct device *dev,
+        struct device_attribute *attr,
+        char *buf)
+{
+    struct iio_dev *dev_info = dev_get_drvdata(dev);
+    struct ads1110_chip_info *chip = dev_info->dev_data;
+    int data=0;
+
+    ads1110_i2c_read_data(chip, &data);
+    return sprintf(buf, "%d\n", data);
+}
+
+static IIO_DEV_ATTR_VALUE(ads1110_show_value);
+
+static ssize_t ads1110_show_conversion_mode(struct device *dev,
+        struct device_attribute *attr,
+        char *buf)
+{
+    struct iio_dev *dev_info = dev_get_drvdata(dev);
+    struct ads1110_chip_info *chip = dev_info->dev_data;
+
+    return sprintf(buf, "%s\n", chip->conversion_mode);
+}
+
+static ssize_t ads1110_store_conversion_mode(struct device *dev,
+        struct device_attribute *attr,
+        const char *buf,
+        size_t len)
+{
+    struct iio_dev *dev_info = dev_get_drvdata(dev);
+    struct ads1110_chip_info *chip = dev_info->dev_data;
+    u8 cfg;
+    int i;
+
+    for (i = 0; i < ADS1110_MAX_CONV_MODE; i++) {
+        if (strncmp(buf, ads1110_conv_mode_table[i].name,
+                strlen(ads1110_conv_mode_table[i].name)) == 0) {
+            ads1110_i2c_read_config(chip, &cfg);
+            chip->conversion_mode = ads1110_conv_mode_table[i].name;
+            cfg &= 0x9F;
+            cfg |= ads1110_conv_mode_table[i].reg_cfg;
+            ads1110_i2c_write_config(chip, cfg);
+            return len;
+        }
+    }
+
+    dev_err(dev, "not supported conversion mode\n");
+
+    return -EINVAL;
+}
+
+static IIO_DEV_ATTR_CONVERSION_MODE(S_IRUGO | S_IWUSR,
+        ads1110_show_conversion_mode,
+        ads1110_store_conversion_mode);
+
+static ssize_t ads1110_show_data_rate(struct device *dev,
+        struct device_attribute *attr,
+        char *buf)
+{
+    struct iio_dev *dev_info = dev_get_drvdata(dev);
+    struct ads1110_chip_info *chip = dev_info->dev_data;
+
+    return sprintf(buf, "%s\n", chip->data_rate);
+}
+
+static ssize_t ads1110_store_data_rate(struct device *dev,
+        struct device_attribute *attr,
+        const char *buf,
+        size_t len)
+{
+    struct iio_dev *dev_info = dev_get_drvdata(dev);
+    struct ads1110_chip_info *chip = dev_info->dev_data;
+    u8 cfg;
+    int i;
+
+    for (i = 0; i < ADS1110_MAX_DATA_RATE; i++) {
+        if (strncmp(buf, ads1110_dr_table[i].name,
+                strlen(ads1110_dr_table[i].name)) == 0) {
+            ads1110_i2c_read_config(chip, &cfg);
+            chip->data_rate = ads1110_dr_table[i].name;
+            cfg &= 0x93;
+            cfg |= ads1110_dr_table[i].reg_cfg;
+            ads1110_i2c_write_config(chip, cfg);
+            return len;
+        }
+    }
+
+    dev_err(dev, "not supported data rate\n");
+
+    return -EINVAL;
+}
+
+static IIO_DEV_ATTR_DATA_RATE(S_IRUGO | S_IWUSR,
+        ads1110_show_data_rate,
+        ads1110_store_data_rate);
+
+static ssize_t ads1110_show_gain(struct device *dev,
+        struct device_attribute *attr,
+        char *buf)
+{
+    struct iio_dev *dev_info = dev_get_drvdata(dev);
+    struct ads1110_chip_info *chip = dev_info->dev_data;
+
+    return sprintf(buf, "%s\n", chip->gain);
+}
+
+static ssize_t ads1110_store_gain(struct device *dev,
+        struct device_attribute *attr,
+        const char *buf,
+        size_t len)
+{
+    struct iio_dev *dev_info = dev_get_drvdata(dev);
+    struct ads1110_chip_info *chip = dev_info->dev_data;
+    u8 cfg;
+    int i;
+
+    for (i = 0; i < ADS1110_MAX_PGA; i++) {
+        if (strncmp(buf, ads1110_pga_table[i].name,
+                strlen(ads1110_pga_table[i].name)) == 0) {
+            ads1110_i2c_read_config(chip, &cfg);
+            chip->gain = ads1110_pga_table[i].name;
+            cfg &= 0x9C;
+            cfg |= ads1110_pga_table[i].reg_cfg;
+            ads1110_i2c_write_config(chip, cfg);
+            return len;
+        }
+    }
+
+    dev_err(dev, "not supported gain\n");
+
+    return -EINVAL;
+}
+
+static IIO_DEV_ATTR_GAIN(S_IRUGO | S_IWUSR,
+        ads1110_show_gain,
+        ads1110_store_gain);
+
+static ssize_t ads1110_store_start_conversion(struct device *dev,
+        struct device_attribute *attr,
+        const char *buf,
+        size_t len)
+{
+    struct iio_dev *dev_info = dev_get_drvdata(dev);
+    struct ads1110_chip_info *chip = dev_info->dev_data;
+    u8 cfg;
+  int ret;
+  long val;
+
+    ret = kstrtoul(buf, 10, &val);
+    if (ret)
+        goto error_ret;
+
+    if ((val > 1) || (val < 0) ) {
+        ret = -EINVAL;
+        goto error_ret;
+    }
+
+    ads1110_i2c_read_config(chip, &cfg);
+
+    if(val)
+      cfg |= ADS1110_CONFIG_SC;
+    else
+      cfg &= ~ADS1110_CONFIG_SC;
+
+
+    ads1110_i2c_write_config(chip, cfg);
+
+error_ret:
+    return ret ? ret : len;
+}
+
+static IIO_DEV_ATTR_START_CONVERSION(S_IWUSR,
+        NULL,
+        ads1110_store_start_conversion);
+
+/*
+ * attributes for ysfs
+ */
+
+static struct attribute *ads1110_attributes[] = {
+ &iio_dev_attr_available_conversion_modes.dev_attr.attr,
+ &iio_dev_attr_available_data_rates.dev_attr.attr,
+ &iio_dev_attr_available_gains.dev_attr.attr,
+ &iio_dev_attr_value.dev_attr.attr,
+ &iio_dev_attr_conversion_mode.dev_attr.attr,
+ &iio_dev_attr_data_rate.dev_attr.attr,
+ &iio_dev_attr_gain.dev_attr.attr,
+ &iio_dev_attr_start_conversion.dev_attr.attr,
+  NULL,
+};
+
+static const struct attribute_group ads1110_attribute_group = {
+  .attrs = ads1110_attributes,
+};
+
+static struct attribute_group ads1110_event_attribute_group = {
+  .attrs = NULL,
+};
+
+static const struct iio_info ads1110_info = {
+  .attrs = &ads1110_attribute_group,
+  .num_interrupt_lines = 1,
+  .event_attrs = &ads1110_event_attribute_group,
+  .driver_module = THIS_MODULE,
+};
+
+/*
+ * device probe and remove
+ */
+
+static int __devinit ads1110_probe(struct i2c_client *client,
+        const struct i2c_device_id *id)
+{
+    int ret = 0, regdone = 0;
+    struct ads1110_chip_info *chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+    if (chip == NULL) {
+        ret = -ENOMEM;
+        goto error_ret;
+    }
+
+    // this is only used for device removal purposes
+    i2c_set_clientdata(client, chip);
+
+    chip->client = client;
+
+    chip->indio_dev = iio_allocate_device(0);
+    if (chip->indio_dev == NULL) {
+        ret = -ENOMEM;
+        goto error_free_chip;
+    }
+
+    // Establish that the iio_dev is a child of the i2c device
+    chip->indio_dev->name = id->name;
+    chip->indio_dev->dev.parent = &client->dev;
+
+    chip->indio_dev->info = &ads1110_info;
+    chip->indio_dev->dev_data = (void *)(chip);
+
+    chip->indio_dev->modes = INDIO_DIRECT_MODE;
+
+    ret = iio_device_register(chip->indio_dev);
+    if (ret)
+        goto error_free_dev;
+    regdone = 1;
+
+    dev_err(&client->dev, "%s ADC registered.\n", id->name);
+
+    return 0;
+
+error_free_dev:
+    if (regdone)
+        iio_device_unregister(chip->indio_dev);
+    else
+        iio_free_device(chip->indio_dev);
+error_free_chip:
+    kfree(chip);
+error_ret:
+    return ret;
+}
+
+static int __devexit ads1110_remove(struct i2c_client *client)
+{
+    struct ads1110_chip_info *chip = i2c_get_clientdata(client);
+    struct iio_dev *indio_dev = chip->indio_dev;
+
+    iio_device_unregister(indio_dev);
+    kfree(chip);
+
+    return 0;
+}
+
+static const struct i2c_device_id ads1110_id[] = {
+    { "ads1110-ed0", 0x48 },
+    { "ads1110-ed1", 0x49 },
+    { "ads1110-ed2", 0x50 },
+    { "ads1110-ed3", 0x51 },
+    { "ads1110-ed4", 0x52 },
+    { "ads1110-ed5", 0x53 },
+    { "ads1110-ed6", 0x54 },
+    { "ads1110-ed7", 0x55 },
+    {}
+};
+
+MODULE_DEVICE_TABLE(i2c, ads1110_id);
+
+static struct i2c_driver ads1110_driver = {
+    .driver = {
+        .name = "ads1110",
+    },
+    .probe = ads1110_probe,
+    .remove = __devexit_p(ads1110_remove),
+    .id_table = ads1110_id,
+};
+
+static __init int ads1110_init(void)
+{
+    return i2c_add_driver(&ads1110_driver);
+}
+
+static __exit void ads1110_exit(void)
+{
+    i2c_del_driver(&ads1110_driver);
+}
+
+MODULE_AUTHOR("Duss Pirmin <pirmin.duss@flytec.ch>");
+MODULE_DESCRIPTION("Texas Instruments ads1110 adc driver");
+MODULE_LICENSE("GPL v2");
+
+module_init(ads1110_init);
+module_exit(ads1110_exit);
diff -Naur aaa/drivers/staging/iio/adc//Kconfig 
bbb/drivers/staging/iio/adc//Kconfig
--- aaa/drivers/staging/iio/adc//Kconfig    2011-12-14 
14:46:58.000000000 +0100
+++ bbb/drivers/staging/iio/adc//Kconfig    2011-12-14 
14:33:01.000000000 +0100
@@ -191,3 +191,14 @@
      help
        Say yes here to include ring buffer support in the MAX1363
        ADC driver.
+
+config ADS1110
+    tristate "Texas Instruments ADS1110 ADC driver"
+    depends on I2C
+    help
+      Say yes here to build support for Texas Instruments ads1110 ADC.
+      Provides direct access via sysfs.
+
+      To compile this driver as a module, choose M here: the
+      module will be called ads1110.
+
diff -Naur aaa/drivers/staging/iio/adc//Makefile 
bbb/drivers/staging/iio/adc//Makefile
--- aaa/drivers/staging/iio/adc//Makefile    2011-12-14 
14:46:58.000000000 +0100
+++ bbb/drivers/staging/iio/adc//Makefile    2011-12-14 
14:32:47.000000000 +0100
@@ -39,3 +39,4 @@
  obj-$(CONFIG_ADT75) += adt75.o
  obj-$(CONFIG_ADT7310) += adt7310.o
  obj-$(CONFIG_ADT7410) += adt7410.o
+obj-$(CONFIG_ADS1110) += ads1110.o