staging: iio: add support for hmc5883/hmc5883l to hmc5843 magnetometer driver

v3 addresses review comments:
* rotate tables (Jonathan Cameron)
* remove trailing space, add newline in sysfs output (Jonathan Cameron)
* split out patch for reorganization of hmc5843_set_rate() (Jonathan Cameron)
* use static table to describe chip variants (Jonathan Cameron)

v2 addresses review comments:
* fixes and cleanups have been split out (Jonathan Cameron)
* constants are generally prefixed HMC5843_, except when related
  specifically to hmc5883 (Jonathan Cameron)
* simplify code and avoid temp buffer in
  hmc5843_show_sampling_frequencies_available() (Lars-Peter Clausen)
* use sysfs_streq() instead of strncmp()/strlen() in
  hmc5843_check_sampling_frequency() (Lars-Peter Clausen)

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/iio/magnetometer/Kconfig b/drivers/staging/iio/magnetometer/Kconfig
index 722c4e1..b9d9325 100644 (file)
--- a/drivers/staging/iio/magnetometer/Kconfig
+++ b/drivers/staging/iio/magnetometer/Kconfig
@@ -15,13 +15,13 @@ config SENSORS_AK8975
          will be called ak8975.
 
 config SENSORS_HMC5843
-       tristate "Honeywell HMC5843 3-Axis Magnetometer"
+       tristate "Honeywell HMC5843/5883/5883L 3-Axis Magnetometer"
        depends on I2C
        help
-         Say Y here to add support for the Honeywell HMC 5843 3-Axis
-         Magnetometer (digital compass).
+         Say Y here to add support for the Honeywell HMC5843, HMC5883 and
+         HMC5883L 3-Axis Magnetometer (digital compass).
 
          To compile this driver as a module, choose M here: the module
-         will be called hmc5843
+         will be called hmc5843.
 
 endmenu

diff --git a/drivers/staging/iio/magnetometer/hmc5843.c b/drivers/staging/iio/magnetometer/hmc5843.c
index 32f19b7..c1fa09f 100644 (file)
--- a/drivers/staging/iio/magnetometer/hmc5843.c
+++ b/drivers/staging/iio/magnetometer/hmc5843.c
@@ -2,6 +2,8 @@
     Author: Shubhrajyoti Datta <shubhrajyoti@ti.com>
     Acknowledgement: Jonathan Cameron <jic23@cam.ac.uk> for valuable inputs.
 
+    Support for HMC5883 and HMC5883L by Peter Meerwald <pmeerw@pmeerw.net>.
+
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
@@ -44,6 +46,11 @@
 #define HMC5843_ID_REG_B                       0x0B
 #define HMC5843_ID_REG_C                       0x0C
 
+enum hmc5843_ids {
+       HMC5843_ID,
+       HMC5883_ID,
+       HMC5883L_ID,
+};
 
 /*
  * Beware: identification of the HMC5883 is still "H43";
@@ -103,8 +110,16 @@ static const int hmc5843_regval_to_nanoscale[] = {
        6173, 7692, 10309, 12821, 18868, 21739, 25641, 35714
 };
 
+static const int hmc5883_regval_to_nanoscale[] = {
+       7812, 9766, 13021, 16287, 24096, 27701, 32573, 45662
+};
+
+static const int hmc5883l_regval_to_nanoscale[] = {
+       7299, 9174, 12195, 15152, 22727, 25641, 30303, 43478
+};
+
 /*
- * From the datasheet:
+ * From the HMC5843 datasheet:
  * Value       | Sensor input field range (Ga) | Gain (counts/milli-Gauss)
  * 0           | (+-)0.7                       | 1620
  * 1           | (+-)1.0                       | 1300
@@ -114,44 +129,75 @@ static const int hmc5843_regval_to_nanoscale[] = {
  * 5           | (+-)3.8                       | 460
  * 6           | (+-)4.5                       | 390
  * 7           | (+-)6.5                       | 280
+ *
+ * From the HMC5883 datasheet:
+ * Value       | Recommended sensor field range (Ga)   | Gain (counts/Gauss)
+ * 0           | (+-)0.9                               | 1280
+ * 1           | (+-)1.2                               | 1024
+ * 2           | (+-)1.9                               | 768
+ * 3           | (+-)2.5                               | 614
+ * 4           | (+-)4.0                               | 415
+ * 5           | (+-)4.6                               | 361
+ * 6           | (+-)5.5                               | 307
+ * 7           | (+-)7.9                               | 219
+ *
+ * From the HMC5883L datasheet:
+ * Value       | Recommended sensor field range (Ga)   | Gain (LSB/Gauss)
+ * 0           | (+-)0.88                              | 1370
+ * 1           | (+-)1.3                               | 1090
+ * 2           | (+-)1.9                               | 820
+ * 3           | (+-)2.5                               | 660
+ * 4           | (+-)4.0                               | 440
+ * 5           | (+-)4.7                               | 390
+ * 6           | (+-)5.6                               | 330
+ * 7           | (+-)8.1                               | 230
  */
 static const int hmc5843_regval_to_input_field_mga[] = {
-       700,
-       1000,
-       1500,
-       2000,
-       3200,
-       3800,
-       4500,
-       6500
+       700, 1000, 1500, 2000, 3200, 3800, 4500, 6500
+};
+
+static const int hmc5883_regval_to_input_field_mga[] = {
+       900, 1200, 1900, 2500, 4000, 4600, 5500, 7900
+};
+
+static const int hmc5883l_regval_to_input_field_mga[] = {
+       880, 1300, 1900, 2500, 4000, 4700, 5600, 8100
 };
 
 /*
  * From the datasheet:
- * Value       | Data output rate (Hz)
- * 0           | 0.5
- * 1           | 1
- * 2           | 2
- * 3           | 5
- * 4           | 10 (default)
- * 5           | 20
- * 6           | 50
- * 7           | Not used
+ * Value       | HMC5843               | HMC5883/HMC5883L
+ *             | Data output rate (Hz) | Data output rate (Hz)
+ * 0           | 0.5                   | 0.75
+ * 1           | 1                     | 1.5
+ * 2           | 2                     | 3
+ * 3           | 5                     | 7.5
+ * 4           | 10 (default)          | 15
+ * 5           | 20                    | 30
+ * 6           | 50                    | 75
+ * 7           | Not used              | Not used
  */
 static const char * const hmc5843_regval_to_sample_freq[] = {
-       "0.5",
-       "1",
-       "2",
-       "5",
-       "10",
-       "20",
-       "50",
+       "0.5", "1", "2", "5", "10", "20", "50",
+};
+
+static const char * const hmc5883_regval_to_sample_freq[] = {
+       "0.75", "1.5", "3", "7.5", "15", "30", "75",
 };
 
 /* Addresses to scan: 0x1E */
 static const unsigned short normal_i2c[] = { HMC5843_I2C_ADDRESS,
                                             I2C_CLIENT_END };
 
+/* Describe chip variants */
+struct hmc5843_chip_info {
+       const struct iio_chan_spec *channels;
+       int num_channels;
+       const char * const *regval_to_sample_freq;
+       const int *regval_to_input_field_mga;
+       const int *regval_to_nanoscale;
+};
+
 /* Each client has this additional data */
 struct hmc5843_data {
        struct mutex lock;
@@ -159,6 +205,7 @@ struct hmc5843_data {
        u8 meas_conf;
        u8 operating_mode;
        u8 range;
+       const struct hmc5843_chip_info *variant;
 };
 
 /* The lower two bits contain the current conversion mode */
@@ -334,7 +381,27 @@ static IIO_DEVICE_ATTR(meas_conf,
                        hmc5843_set_measurement_configuration,
                        0);
 
-static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("0.5 1 2 5 10 20 50");
+static ssize_t hmc5843_show_sampling_frequencies_available(struct device *dev,
+                                               struct device_attribute *attr,
+                                               char *buf)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct hmc5843_data *data = iio_priv(indio_dev);
+       ssize_t total_n = 0;
+       int i;
+
+       for (i = 0; i < HMC5843_RATE_NOT_USED; i++) {
+               ssize_t n = sprintf(buf, "%s ", data->variant->regval_to_sample_freq[i]);
+               buf += n;
+               total_n += n;
+       }
+       /* replace trailing space by newline */
+       buf[-1] = '\n';
+
+       return total_n;
+}
+
+static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(hmc5843_show_sampling_frequencies_available);
 
 static s32 hmc5843_set_rate(struct i2c_client *client,
                                u8 rate)
@@ -356,12 +423,11 @@ static s32 hmc5843_set_rate(struct i2c_client *client,
 static int hmc5843_check_sampling_frequency(struct hmc5843_data *data,
                                                const char *buf)
 {
-       const char * const *samp_freq = hmc5843_regval_to_sample_freq;
+       const char * const *samp_freq = data->variant->regval_to_sample_freq;
        int i;
 
        for (i = 0; i < HMC5843_RATE_NOT_USED; i++) {
-               if (strncmp(buf, samp_freq[i],
-                       strlen(samp_freq[i])) == 0)
+               if (sysfs_streq(buf, samp_freq[i]))
                        return i;
        }
 
@@ -404,13 +470,14 @@ static ssize_t hmc5843_show_sampling_frequency(struct device *dev,
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);
        struct i2c_client *client = to_i2c_client(indio_dev->dev.parent);
        struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+       struct hmc5843_data *data = iio_priv(indio_dev);
        s32 rate;
 
        rate = i2c_smbus_read_byte_data(client, this_attr->address);
        if (rate < 0)
                return rate;
        rate = (rate & HMC5843_RATE_BITMASK) >> HMC5843_RATE_OFFSET;
-       return sprintf(buf, "%s\n", hmc5843_regval_to_sample_freq[rate]);
+       return sprintf(buf, "%s\n", data->variant->regval_to_sample_freq[rate]);
 }
 
 static IIO_DEVICE_ATTR(sampling_frequency,
@@ -428,7 +495,7 @@ static ssize_t hmc5843_show_range_gain(struct device *dev,
        struct hmc5843_data *data = iio_priv(indio_dev);
 
        range = data->range;
-       return sprintf(buf, "%d\n", hmc5843_regval_to_input_field_mga[range]);
+       return sprintf(buf, "%d\n", data->variant->regval_to_input_field_mga[range]);
 }
 
 static ssize_t hmc5843_set_range_gain(struct device *dev,
@@ -486,7 +553,7 @@ static int hmc5843_read_raw(struct iio_dev *indio_dev,
                                                val);
        case IIO_CHAN_INFO_SCALE:
                *val = 0;
-               *val2 = hmc5843_regval_to_nanoscale[data->range];
+               *val2 = data->variant->regval_to_nanoscale[data->range];
                return IIO_VAL_INT_PLUS_NANO;
        };
        return -EINVAL;
@@ -508,12 +575,18 @@ static const struct iio_chan_spec hmc5843_channels[] = {
        HMC5843_CHANNEL(Z, HMC5843_DATA_OUT_Z_MSB_REG),
 };
 
+static const struct iio_chan_spec hmc5883_channels[] = {
+       HMC5843_CHANNEL(X, HMC5843_DATA_OUT_X_MSB_REG),
+       HMC5843_CHANNEL(Y, HMC5883_DATA_OUT_Y_MSB_REG),
+       HMC5843_CHANNEL(Z, HMC5883_DATA_OUT_Z_MSB_REG),
+};
+
 static struct attribute *hmc5843_attributes[] = {
        &iio_dev_attr_meas_conf.dev_attr.attr,
        &iio_dev_attr_operating_mode.dev_attr.attr,
        &iio_dev_attr_sampling_frequency.dev_attr.attr,
        &iio_dev_attr_in_magn_range.dev_attr.attr,
-       &iio_const_attr_sampling_frequency_available.dev_attr.attr,
+       &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
        NULL
 };
 
@@ -521,6 +594,33 @@ static const struct attribute_group hmc5843_group = {
        .attrs = hmc5843_attributes,
 };
 
+static const struct hmc5843_chip_info hmc5843_chip_info_tbl[] = {
+       [HMC5843_ID] = {
+               .channels = hmc5843_channels,
+               .num_channels = ARRAY_SIZE(hmc5843_channels),
+               .regval_to_sample_freq = hmc5843_regval_to_sample_freq,
+               .regval_to_input_field_mga =
+                       hmc5843_regval_to_input_field_mga,
+               .regval_to_nanoscale = hmc5843_regval_to_nanoscale,
+       },
+       [HMC5883_ID] = {
+               .channels = hmc5883_channels,
+               .num_channels = ARRAY_SIZE(hmc5883_channels),
+               .regval_to_sample_freq = hmc5883_regval_to_sample_freq,
+               .regval_to_input_field_mga =
+                       hmc5883_regval_to_input_field_mga,
+               .regval_to_nanoscale = hmc5883_regval_to_nanoscale,
+       },
+       [HMC5883L_ID] = {
+               .channels = hmc5883_channels,
+               .num_channels = ARRAY_SIZE(hmc5883_channels),
+               .regval_to_sample_freq = hmc5883_regval_to_sample_freq,
+               .regval_to_input_field_mga =
+                       hmc5883l_regval_to_input_field_mga,
+               .regval_to_nanoscale = hmc5883l_regval_to_nanoscale,
+       },
+};
+
 static int hmc5843_detect(struct i2c_client *client,
                          struct i2c_board_info *info)
 {
@@ -540,19 +640,23 @@ static int hmc5843_detect(struct i2c_client *client,
        return 0;
 }
 
-/* Called when we have found a new HMC5843 */
-static void hmc5843_init_client(struct i2c_client *client)
+/* Called when we have found a new HMC58X3 */
+static void hmc5843_init_client(struct i2c_client *client,
+                               const struct i2c_device_id *id)
 {
        struct iio_dev *indio_dev = i2c_get_clientdata(client);
        struct hmc5843_data *data = iio_priv(indio_dev);
 
+       data->variant = &hmc5843_chip_info_tbl[id->driver_data];
+       indio_dev->channels = data->variant->channels;
+       indio_dev->num_channels = data->variant->num_channels;
        hmc5843_set_meas_conf(client, data->meas_conf);
        hmc5843_set_rate(client, data->rate);
        hmc5843_configure(client, data->operating_mode);
        i2c_smbus_write_byte_data(client, HMC5843_CONFIG_REG_B, data->range);
        mutex_init(&data->lock);
 
-       pr_info("HMC5843 initialized\n");
+       pr_info("%s initialized\n", id->name);
 }
 
 static const struct iio_info hmc5843_info = {
@@ -581,12 +685,10 @@ static int hmc5843_probe(struct i2c_client *client,
        data->operating_mode = HMC5843_MODE_CONVERSION_CONTINUOUS;
 
        i2c_set_clientdata(client, indio_dev);
-       hmc5843_init_client(client);
+       hmc5843_init_client(client, id);
 
        indio_dev->info = &hmc5843_info;
        indio_dev->name = id->name;
-       indio_dev->channels = hmc5843_channels;
-       indio_dev->num_channels = ARRAY_SIZE(hmc5843_channels);
        indio_dev->dev.parent = &client->dev;
        indio_dev->modes = INDIO_DIRECT_MODE;
 
@@ -639,7 +741,9 @@ static SIMPLE_DEV_PM_OPS(hmc5843_pm_ops, hmc5843_suspend, hmc5843_resume);
 #endif
 
 static const struct i2c_device_id hmc5843_id[] = {
-       { "hmc5843", 0 },
+       { "hmc5843", HMC5843_ID },
+       { "hmc5883", HMC5883_ID },
+       { "hmc5883l", HMC5883L_ID },
        { }
 };
 MODULE_DEVICE_TABLE(i2c, hmc5843_id);
@@ -658,5 +762,5 @@ static struct i2c_driver hmc5843_driver = {
 module_i2c_driver(hmc5843_driver);
 
 MODULE_AUTHOR("Shubhrajyoti Datta <shubhrajyoti@ti.com");
-MODULE_DESCRIPTION("HMC5843 driver");
+MODULE_DESCRIPTION("HMC5843/5883/5883L driver");
 MODULE_LICENSE("GPL");