diff options
| -rw-r--r-- | Documentation/devicetree/bindings/hwmon/ads1015.txt | 88 | ||||
| -rw-r--r-- | Documentation/hwmon/ads1015 | 49 | ||||
| -rw-r--r-- | drivers/hwmon/ads1015.c | 149 | ||||
| -rw-r--r-- | include/linux/i2c/ads1015.h | 10 |
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 */ |