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
2011-03-21 17:59:37 +01:00
کامیت شده توسط Jean Delvare
والد fdf241a8ed
کامیت c0046867f3
4فایلهای تغییر یافته به همراه207 افزوده شده و 81 حذف شده

مشاهده پرونده

@@ -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);