hwmon: (ads1015) Add support for ADS1115

This patch adds support for ads1115 device to ads1015 driver.
Based on work of Emiliano Carnati <carnatiatebneuro.com>.
Tested on ARM CPU based board.

Signed-off-by: Evgeniy A. Dushistov <dushistov@mail.ru>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

2 files changed, 23 insertions, 8 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index e989f7fd645b..47b3e5821cb8 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1202,8 +1202,8 @@ config SENSORS_ADS1015
         tristate "Texas Instruments ADS1015"
         depends on I2C
         help
-          If you say yes here you get support for Texas Instruments ADS1015
-          12-bit 4-input ADC device.
+          If you say yes here you get support for Texas Instruments
+          ADS1015/ADS1115 12/16-bit 4-input ADC device.
 
           This driver can also be built as a module.  If so, the module
           will be called ads1015.
diff --git a/drivers/hwmon/ads1015.c b/drivers/hwmon/ads1015.c
index 2798246ad814..7f9dc2f86b63 100644
--- a/drivers/hwmon/ads1015.c
+++ b/drivers/hwmon/ads1015.c
@@ -46,17 +46,28 @@ static const unsigned int fullscale_table[8] = {
         6144, 4096, 2048, 1024, 512, 256, 256, 256 };
 
 /* Data rates in samples per second */
-static const unsigned int data_rate_table[8] = {
-        128, 250, 490, 920, 1600, 2400, 3300, 3300 };
+static const unsigned int data_rate_table_1015[8] = {
+        128, 250, 490, 920, 1600, 2400, 3300, 3300
+};
+
+static const unsigned int data_rate_table_1115[8] = {
+        8, 16, 32, 64, 128, 250, 475, 860
+};
 
 #define ADS1015_DEFAULT_CHANNELS 0xff
 #define ADS1015_DEFAULT_PGA 2
 #define ADS1015_DEFAULT_DATA_RATE 4
 
+enum ads1015_chips {
+        ads1015,
+        ads1115,
+};
+
 struct ads1015_data {
         struct device *hwmon_dev;
         struct mutex update_lock; /* mutex protect updates */
         struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
+        enum ads1015_chips id;
 };
 
 static int ads1015_read_adc(struct i2c_client *client, unsigned int channel)
@@ -66,6 +77,8 @@ static int ads1015_read_adc(struct i2c_client *client, unsigned int channel)
         unsigned int pga = data->channel_data[channel].pga;
         unsigned int data_rate = data->channel_data[channel].data_rate;
         unsigned int conversion_time_ms;
+        const unsigned int * const rate_table = data->id == ads1115 ?
+                data_rate_table_1115 : data_rate_table_1015;
         int res;
 
         mutex_lock(&data->update_lock);
@@ -75,7 +88,7 @@ static int ads1015_read_adc(struct i2c_client *client, unsigned int channel)
         if (res < 0)
                 goto err_unlock;
         config = res;
-        conversion_time_ms = DIV_ROUND_UP(1000, data_rate_table[data_rate]);
+        conversion_time_ms = DIV_ROUND_UP(1000, rate_table[data_rate]);
 
         /* setup and start single conversion */
         config &= 0x001f;
@@ -113,8 +126,9 @@ static int ads1015_reg_to_mv(struct i2c_client *client, unsigned int channel,
         struct ads1015_data *data = i2c_get_clientdata(client);
         unsigned int pga = data->channel_data[channel].pga;
         int fullscale = fullscale_table[pga];
+        const unsigned mask = data->id == ads1115 ? 0x7fff : 0x7ff0;
 
-        return DIV_ROUND_CLOSEST(reg * fullscale, 0x7ff0);
+        return DIV_ROUND_CLOSEST(reg * fullscale, mask);
 }
 
 /* sysfs callback function */
@@ -257,7 +271,7 @@ static int ads1015_probe(struct i2c_client *client,
                             GFP_KERNEL);
         if (!data)
                 return -ENOMEM;
-
+        data->id = id->driver_data;
         i2c_set_clientdata(client, data);
         mutex_init(&data->update_lock);
 
@@ -286,7 +300,8 @@ exit_remove:
 }
 
 static const struct i2c_device_id ads1015_id[] = {
-        { "ads1015", 0 },
+        { "ads1015",  ads1015},
+        { "ads1115",  ads1115},
         { }
 };
 MODULE_DEVICE_TABLE(i2c, ads1015_id);