4 files changed, 211 insertions, 85 deletions

diff --git a/Documentation/devicetree/bindings/hwmon/ads1015.txt b/Documentation/devicetree/bindings/hwmon/ads1015.txt
index 0f30616384c5..918a507d1159 100644
--- a/Documentation/devicetree/bindings/hwmon/ads1015.txt
+++ b/Documentation/devicetree/bindings/hwmon/ads1015.txt
@@ -5,25 +5,69 @@ This device is a 12-bit A-D converter with 4 inputs.
 The inputs can be used single ended or in certain differential combinations.
 
 For configuration all possible combinations are mapped to 8 channels:
-0: Voltage over AIN0 and AIN1.
-1: Voltage over AIN0 and AIN3.
-2: Voltage over AIN1 and AIN3.
-3: Voltage over AIN2 and AIN3.
-4: Voltage over AIN0 and GND.
-5: Voltage over AIN1 and GND.
-6: Voltage over AIN2 and GND.
-7: Voltage over AIN3 and GND.
-
-Optional properties:
-
- - exported-channels : exported_channels is a bitmask that specifies which
-                       channels should be accessable by the user.
-
-Example:
-ads1015@49 {
-        compatible = "ti,ads1015";
-        reg = <0x49>;
-        exported-channels = <0x14>;
-};
-
-In this example only channel 2 and 4 would be accessable by the user.
+  0: Voltage over AIN0 and AIN1.
+  1: Voltage over AIN0 and AIN3.
+  2: Voltage over AIN1 and AIN3.
+  3: Voltage over AIN2 and AIN3.
+  4: Voltage over AIN0 and GND.
+  5: Voltage over AIN1 and GND.
+  6: Voltage over AIN2 and GND.
+  7: Voltage over AIN3 and GND.
+
+Each channel can be configured individually:
+ - pga is the programmable gain amplifier (values are full scale)
+    0: +/- 6.144 V
+    1: +/- 4.096 V
+    2: +/- 2.048 V (default)
+    3: +/- 1.024 V
+    4: +/- 0.512 V
+    5: +/- 0.256 V
+ - data_rate in samples per second
+    0: 128
+    1: 250
+    2: 490
+    3: 920
+    4: 1600 (default)
+    5: 2400
+    6: 3300
+
+1) The /ads1015 node
+
+  Required properties:
+
+   - compatible : must be "ti,ads1015"
+   - reg : I2C bus address of the device
+   - #address-cells : must be <1>
+   - #size-cells : must be <0>
+
+  The node contains child nodes for each channel that the platform uses.
+
+  Example ADS1015 node:
+
+    ads1015@49 {
+            compatible = "ti,ads1015";
+            reg = <0x49>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            [ child node definitions... ]
+    }
+
+2) channel nodes
+
+  Required properties:
+
+   - reg : the channel number
+
+  Optional properties:
+
+   - ti,gain : the programmable gain amplifier setting
+   - ti,datarate : the converter data rate
+
+  Example ADS1015 channel node:
+
+    channel@4 {
+            reg = <4>;
+            ti,gain = <3>;
+            ti,datarate = <5>;
+    };
diff --git a/Documentation/hwmon/ads1015 b/Documentation/hwmon/ads1015
index 56ee7977b1a8..f6fe9c203733 100644
--- a/Documentation/hwmon/ads1015
+++ b/Documentation/hwmon/ads1015
@@ -19,7 +19,7 @@ This device is a 12-bit A-D converter with 4 inputs.
 
 The inputs can be used single ended or in certain differential combinations.
 
-The inputs can be exported to 8 sysfs input files in0_input - in7_input:
+The inputs can be made available by 8 sysfs input files in0_input - in7_input:
 in0: Voltage over AIN0 and AIN1.
 in1: Voltage over AIN0 and AIN3.
 in2: Voltage over AIN1 and AIN3.
@@ -29,39 +29,44 @@ in5: Voltage over AIN1 and GND.
 in6: Voltage over AIN2 and GND.
 in7: Voltage over AIN3 and GND.
 
-Which inputs are exported can be configured using platform data or devicetree.
+Which inputs are available can be configured using platform data or devicetree.
 
 By default all inputs are exported.
 
 Platform Data
 -------------
 
-In linux/i2c/ads1015.h platform data is defined as:
-
-struct ads1015_platform_data {
-        unsigned int exported_channels;
-};
-
-exported_channels is a bitmask that specifies which inputs should be exported.
+In linux/i2c/ads1015.h platform data is defined, channel_data contains
+configuration data for the used input combinations:
+- pga is the programmable gain amplifier (values are full scale)
+  0: +/- 6.144 V
+  1: +/- 4.096 V
+  2: +/- 2.048 V
+  3: +/- 1.024 V
+  4: +/- 0.512 V
+  5: +/- 0.256 V
+- data_rate in samples per second
+  0: 128
+  1: 250
+  2: 490
+  3: 920
+  4: 1600
+  5: 2400
+  6: 3300
 
 Example:
 struct ads1015_platform_data data = {
-        .exported_channels = (1 << 2) | (1 << 4)
+        .channel_data = {
+                [2] = { .enabled = true, .pga = 1, .data_rate = 0 },
+                [4] = { .enabled = true, .pga = 4, .data_rate = 5 },
+        }
 };
 
-In this case only in2_input and in4_input would be created.
+In this case only in2_input (FS +/- 4.096 V, 128 SPS) and in4_input
+(FS +/- 0.512 V, 2400 SPS) would be created.
 
 Devicetree
 ----------
 
-The ads1015 node may have an "exported-channels" property.
-exported_channels is a bitmask that specifies which inputs should be exported.
-
-Example:
-ads1015@49 {
-        compatible = "ti,ads1015";
-        reg = <0x49>;
-        exported-channels = < 0x14 >;
-};
-
-In this case only in2_input and in4_input would be created.
+Configuration is also possible via devicetree:
+Documentation/devicetree/bindings/hwmon/ads1015.txt
diff --git a/drivers/hwmon/ads1015.c b/drivers/hwmon/ads1015.c
index fa02f20b79ff..e9beeda4cbe5 100644
--- a/drivers/hwmon/ads1015.c
+++ b/drivers/hwmon/ads1015.c
@@ -45,12 +45,18 @@ enum {
 static const unsigned int fullscale_table[8] = {
         6144, 4096, 2048, 1024, 512, 256, 256, 256 };
 
-#define ADS1015_CONFIG_CHANNELS 8
+/* Data rates in samples per second */
+static const unsigned int data_rate_table[8] = {
+        128, 250, 490, 920, 1600, 2400, 3300, 3300 };
+
 #define ADS1015_DEFAULT_CHANNELS 0xff
+#define ADS1015_DEFAULT_PGA 2
+#define ADS1015_DEFAULT_DATA_RATE 4
 
 struct ads1015_data {
         struct device *hwmon_dev;
         struct mutex update_lock; /* mutex protect updates */
+        struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
 };
 
 static s32 ads1015_read_reg(struct i2c_client *client, unsigned int reg)
@@ -71,40 +77,42 @@ static int ads1015_read_value(struct i2c_client *client, unsigned int channel,
 {
         u16 config;
         s16 conversion;
-        unsigned int pga;
-        int fullscale;
-        unsigned int k;
         struct ads1015_data *data = i2c_get_clientdata(client);
+        unsigned int pga = data->channel_data[channel].pga;
+        int fullscale;
+        unsigned int data_rate = data->channel_data[channel].data_rate;
+        unsigned int conversion_time_ms;
         int res;
 
         mutex_lock(&data->update_lock);
 
-        /* get fullscale voltage */
+        /* get channel parameters */
         res = ads1015_read_reg(client, ADS1015_CONFIG);
         if (res < 0)
                 goto err_unlock;
         config = res;
-        pga = (config >> 9) & 0x0007;
         fullscale = fullscale_table[pga];
+        conversion_time_ms = DIV_ROUND_UP(1000, data_rate_table[data_rate]);
 
-        /* set channel and start single conversion */
-        config &= ~(0x0007 << 12);
-        config |= (1 << 15) | (1 << 8) | (channel & 0x0007) << 12;
+        /* setup and start single conversion */
+        config &= 0x001f;
+        config |= (1 << 15) | (1 << 8);
+        config |= (channel & 0x0007) << 12;
+        config |= (pga & 0x0007) << 9;
+        config |= (data_rate & 0x0007) << 5;
 
-        /* wait until conversion finished */
         res = ads1015_write_reg(client, ADS1015_CONFIG, config);
         if (res < 0)
                 goto err_unlock;
-        for (k = 0; k < 5; ++k) {
-                msleep(1);
-                res = ads1015_read_reg(client, ADS1015_CONFIG);
-                if (res < 0)
-                        goto err_unlock;
-                config = res;
-                if (config & (1 << 15))
-                        break;
-        }
-        if (k == 5) {
+
+        /* wait until conversion finished */
+        msleep(conversion_time_ms);
+        res = ads1015_read_reg(client, ADS1015_CONFIG);
+        if (res < 0)
+                goto err_unlock;
+        config = res;
+        if (!(config & (1 << 15))) {
+                /* conversion not finished in time */
                 res = -EIO;
                 goto err_unlock;
         }
@@ -160,35 +168,97 @@ static int ads1015_remove(struct i2c_client *client)
         int k;
 
         hwmon_device_unregister(data->hwmon_dev);
-        for (k = 0; k < ADS1015_CONFIG_CHANNELS; ++k)
+        for (k = 0; k < ADS1015_CHANNELS; ++k)
                 device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
         kfree(data);
         return 0;
 }
 
-static unsigned int ads1015_get_exported_channels(struct i2c_client *client)
-{
-        struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
 #ifdef CONFIG_OF
-        struct device_node *np = client->dev.of_node;
-        const __be32 *of_channels;
-        int of_channels_size;
+static int ads1015_get_channels_config_of(struct i2c_client *client)
+{
+        struct ads1015_data *data = i2c_get_clientdata(client);
+        struct device_node *node;
+
+        if (!client->dev.of_node
+            || !of_get_next_child(client->dev.of_node, NULL))
+                return -EINVAL;
+
+        for_each_child_of_node(client->dev.of_node, node) {
+                const __be32 *property;
+                int len;
+                unsigned int channel;
+                unsigned int pga = ADS1015_DEFAULT_PGA;
+                unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
+
+                property = of_get_property(node, "reg", &len);
+                if (!property || len != sizeof(int)) {
+                        dev_err(&client->dev, "invalid reg on %s\n",
+                                node->full_name);
+                        continue;
+                }
+
+                channel = be32_to_cpup(property);
+                if (channel > ADS1015_CHANNELS) {
+                        dev_err(&client->dev,
+                                "invalid channel index %d on %s\n",
+                                channel, node->full_name);
+                        continue;
+                }
+
+                property = of_get_property(node, "ti,gain", &len);
+                if (property && len == sizeof(int)) {
+                        pga = be32_to_cpup(property);
+                        if (pga > 6) {
+                                dev_err(&client->dev,
+                                        "invalid gain on %s\n",
+                                        node->full_name);
+                        }
+                }
+
+                property = of_get_property(node, "ti,datarate", &len);
+                if (property && len == sizeof(int)) {
+                        data_rate = be32_to_cpup(property);
+                        if (data_rate > 7) {
+                                dev_err(&client->dev,
+                                        "invalid data_rate on %s\n",
+                                        node->full_name);
+                        }
+                }
+
+                data->channel_data[channel].enabled = true;
+                data->channel_data[channel].pga = pga;
+                data->channel_data[channel].data_rate = data_rate;
+        }
+
+        return 0;
+}
 #endif
 
+static void ads1015_get_channels_config(struct i2c_client *client)
+{
+        unsigned int k;
+        struct ads1015_data *data = i2c_get_clientdata(client);
+        struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
+
         /* prefer platform data */
-        if (pdata)
-                return pdata->exported_channels;
+        if (pdata) {
+                memcpy(data->channel_data, pdata->channel_data,
+                       sizeof(data->channel_data));
+                return;
+        }
 
 #ifdef CONFIG_OF
-        /* fallback on OF */
-        of_channels = of_get_property(np, "exported-channels",
-                                      &of_channels_size);
-        if (of_channels && (of_channels_size == sizeof(*of_channels)))
-                return be32_to_cpup(of_channels);
+        if (!ads1015_get_channels_config_of(client))
+                return;
 #endif
 
         /* fallback on default configuration */
-        return ADS1015_DEFAULT_CHANNELS;
+        for (k = 0; k < ADS1015_CHANNELS; ++k) {
+                data->channel_data[k].enabled = true;
+                data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
+                data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
+        }
 }
 
 static int ads1015_probe(struct i2c_client *client,
@@ -196,7 +266,6 @@ static int ads1015_probe(struct i2c_client *client,
 {
         struct ads1015_data *data;
         int err;
-        unsigned int exported_channels;
         unsigned int k;
 
         data = kzalloc(sizeof(struct ads1015_data), GFP_KERNEL);
@@ -209,9 +278,9 @@ static int ads1015_probe(struct i2c_client *client,
         mutex_init(&data->update_lock);
 
         /* build sysfs attribute group */
-        exported_channels = ads1015_get_exported_channels(client);
-        for (k = 0; k < ADS1015_CONFIG_CHANNELS; ++k) {
-                if (!(exported_channels & (1<<k)))
+        ads1015_get_channels_config(client);
+        for (k = 0; k < ADS1015_CHANNELS; ++k) {
+                if (!data->channel_data[k].enabled)
                         continue;
                 err = device_create_file(&client->dev, &ads1015_in[k].dev_attr);
                 if (err)
@@ -227,7 +296,7 @@ static int ads1015_probe(struct i2c_client *client,
         return 0;
 
 exit_remove:
-        for (k = 0; k < ADS1015_CONFIG_CHANNELS; ++k)
+        for (k = 0; k < ADS1015_CHANNELS; ++k)
                 device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
 exit_free:
         kfree(data);
diff --git a/include/linux/i2c/ads1015.h b/include/linux/i2c/ads1015.h
index 8541c6acfafd..d5aa2a045669 100644
--- a/include/linux/i2c/ads1015.h
+++ b/include/linux/i2c/ads1015.h
@@ -21,8 +21,16 @@
 #ifndef LINUX_ADS1015_H
 #define LINUX_ADS1015_H
 
+#define ADS1015_CHANNELS 8
+
+struct ads1015_channel_data {
+        bool enabled;
+        unsigned int pga;
+        unsigned int data_rate;
+};
+
 struct ads1015_platform_data {
-        unsigned int exported_channels;
+        struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
 };
 
 #endif /* LINUX_ADS1015_H */