forked from Minki/linux
hwmon: (ads1015) Make gain and datarate configurable
Configuration for ads1015 gain and datarate is possible via devicetree or platform data. This is a followup patch to previous ads1015 patches on Jean Delvares tree. Signed-off-by: Dirk Eibach <eibach@gdsys.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
Dirk Eibach
Jean Delvare
parent
fdf241a8ed
commit
c0046867f3
@ -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.
|
||||
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:
|
||||
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
|
||||
|
||||
- exported-channels : exported_channels is a bitmask that specifies which
|
||||
channels should be accessable by the user.
|
||||
1) The /ads1015 node
|
||||
|
||||
Example:
|
||||
ads1015@49 {
|
||||
compatible = "ti,ads1015";
|
||||
reg = <0x49>;
|
||||
exported-channels = <0x14>;
|
||||
};
|
||||
Required properties:
|
||||
|
||||
In this example only channel 2 and 4 would be accessable by the user.
|
||||
- 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>;
|
||||
};
|
||||
|
||||
@ -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
|
||||
|
||||
@ -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);
|
||||
|
||||
@ -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 */
|
||||
|
||||
Loading…
Reference in New Issue
Block a user