hwmon: (ads7828) add support for ADS7830
The ADS7830 device is almost the same as the ADS7828,
except that it does 8-bit sampling, instead of 12-bit.
This patch extends the ads7828 driver to support this chip.
Signed-off-by: Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c
index 42914fc..409b5c1 100644
--- a/drivers/hwmon/ads7828.c
+++ b/drivers/hwmon/ads7828.c
@@ -1,11 +1,13 @@
/*
- * ads7828.c - lm_sensors driver for ads7828 12-bit 8-channel ADC
+ * ads7828.c - driver for TI ADS7828 8-channel A/D converter and compatibles
* (C) 2007 EADS Astrium
*
* This driver is based on the lm75 and other lm_sensors/hwmon drivers
*
* Written by Steve Hardy <shardy@redhat.com>
*
+ * ADS7830 support, by Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
+ *
* For further information, see the Documentation/hwmon/ads7828 file.
*
* This program is free software; you can redistribute it and/or modify
@@ -43,6 +45,9 @@
#define ADS7828_EXT_VREF_MV_MIN 50 /* External vref min value 0.05V */
#define ADS7828_EXT_VREF_MV_MAX 5250 /* External vref max value 5.25V */
+/* List of supported devices */
+enum ads7828_chips { ads7828, ads7830 };
+
/* Client specific data */
struct ads7828_data {
struct device *hwmon_dev;
@@ -55,6 +60,7 @@
unsigned int vref_mv; /* voltage reference value */
u8 cmd_byte; /* Command byte without channel bits */
unsigned int lsb_resol; /* Resolution of the ADC sample LSB */
+ s32 (*read_channel)(const struct i2c_client *client, u8 command);
};
/* Command byte C2,C1,C0 - see datasheet */
@@ -78,8 +84,7 @@
for (ch = 0; ch < ADS7828_NCH; ch++) {
u8 cmd = ads7828_cmd_byte(data->cmd_byte, ch);
- data->adc_input[ch] =
- i2c_smbus_read_word_swapped(client, cmd);
+ data->adc_input[ch] = data->read_channel(client, cmd);
}
data->last_updated = jiffies;
data->valid = true;
@@ -164,7 +169,14 @@
else
data->vref_mv = ADS7828_INT_VREF_MV;
- data->lsb_resol = DIV_ROUND_CLOSEST(data->vref_mv * 1000, 4096);
+ /* ADS7828 uses 12-bit samples, while ADS7830 is 8-bit */
+ if (id->driver_data == ads7828) {
+ data->lsb_resol = DIV_ROUND_CLOSEST(data->vref_mv * 1000, 4096);
+ data->read_channel = i2c_smbus_read_word_swapped;
+ } else {
+ data->lsb_resol = DIV_ROUND_CLOSEST(data->vref_mv * 1000, 256);
+ data->read_channel = i2c_smbus_read_byte_data;
+ }
data->cmd_byte = data->ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3;
if (!data->diff_input)
@@ -191,7 +203,8 @@
}
static const struct i2c_device_id ads7828_device_ids[] = {
- { "ads7828", 0 },
+ { "ads7828", ads7828 },
+ { "ads7830", ads7830 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ads7828_device_ids);
@@ -210,4 +223,4 @@
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Steve Hardy <shardy@redhat.com>");
-MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter");
+MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter and compatibles");