*
* Written by Steve Hardy <shardy@redhat.com>
*
- * Datasheet available at: http://focus.ti.com/lit/ds/symlink/ads7828.pdf
+ * For further information, see the Documentation/hwmon/ads7828 file.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/jiffies.h>
-#include <linux/i2c.h>
+#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
-#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/platform_data/ads7828.h>
+#include <linux/slab.h>
/* The ADS7828 registers */
-#define ADS7828_NCH 8 /* 8 channels of 12-bit A-D supported */
-#define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */
-#define ADS7828_CMD_SD_DIFF 0x00 /* Differential inputs */
-#define ADS7828_CMD_PD0 0x0 /* Power Down between A-D conversions */
-#define ADS7828_CMD_PD1 0x04 /* Internal ref OFF && A-D ON */
-#define ADS7828_CMD_PD2 0x08 /* Internal ref ON && A-D OFF */
-#define ADS7828_CMD_PD3 0x0C /* Internal ref ON && A-D ON */
-#define ADS7828_INT_VREF_MV 2500 /* Internal vref is 2.5V, 2500mV */
-
-/* Addresses to scan */
-static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
- I2C_CLIENT_END };
-
-/* Module parameters */
-static bool se_input = 1; /* Default is SE, 0 == diff */
-static bool int_vref = 1; /* Default is internal ref ON */
-static int vref_mv = ADS7828_INT_VREF_MV; /* set if vref != 2.5V */
-module_param(se_input, bool, S_IRUGO);
-module_param(int_vref, bool, S_IRUGO);
-module_param(vref_mv, int, S_IRUGO);
-
-/* Global Variables */
-static u8 ads7828_cmd_byte; /* cmd byte without channel bits */
-static unsigned int ads7828_lsb_resol; /* resolution of the ADC sample lsb */
-
-/* Each client has this additional data */
+#define ADS7828_NCH 8 /* 8 channels supported */
+#define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */
+#define ADS7828_CMD_PD1 0x04 /* Internal vref OFF && A/D ON */
+#define ADS7828_CMD_PD3 0x0C /* Internal vref ON && A/D ON */
+#define ADS7828_INT_VREF_MV 2500 /* Internal vref is 2.5V, 2500mV */
+#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 */
+
+/* Client specific data */
struct ads7828_data {
struct device *hwmon_dev;
- struct mutex update_lock; /* mutex protect updates */
- char valid; /* !=0 if following fields are valid */
- unsigned long last_updated; /* In jiffies */
- u16 adc_input[ADS7828_NCH]; /* ADS7828_NCH 12-bit samples */
+ struct mutex update_lock; /* Mutex protecting updates */
+ unsigned long last_updated; /* Last updated time (in jiffies) */
+ u16 adc_input[ADS7828_NCH]; /* ADS7828_NCH samples */
+ bool valid; /* Validity flag */
+ bool diff_input; /* Differential input */
+ bool ext_vref; /* External voltage reference */
+ 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 */
};
-/* Function declaration - necessary due to function dependencies */
-static int ads7828_detect(struct i2c_client *client,
- struct i2c_board_info *info);
-static int ads7828_probe(struct i2c_client *client,
- const struct i2c_device_id *id);
-
-static inline u8 channel_cmd_byte(int ch)
+/* Command byte C2,C1,C0 - see datasheet */
+static inline u8 ads7828_cmd_byte(u8 cmd, int ch)
{
- /* cmd byte C2,C1,C0 - see datasheet */
- u8 cmd = (((ch>>1) | (ch&0x01)<<2)<<4);
- cmd |= ads7828_cmd_byte;
- return cmd;
+ return cmd | (((ch >> 1) | (ch & 0x01) << 2) << 4);
}
/* Update data for the device (all 8 channels) */
dev_dbg(&client->dev, "Starting ads7828 update\n");
for (ch = 0; ch < ADS7828_NCH; ch++) {
- u8 cmd = channel_cmd_byte(ch);
+ u8 cmd = ads7828_cmd_byte(data->cmd_byte, ch);
data->adc_input[ch] =
i2c_smbus_read_word_swapped(client, cmd);
}
data->last_updated = jiffies;
- data->valid = 1;
+ data->valid = true;
}
mutex_unlock(&data->update_lock);
}
/* sysfs callback function */
-static ssize_t show_in(struct device *dev, struct device_attribute *da,
- char *buf)
+static ssize_t ads7828_show_in(struct device *dev, struct device_attribute *da,
+ char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct ads7828_data *data = ads7828_update_device(dev);
- /* Print value (in mV as specified in sysfs-interface documentation) */
- return sprintf(buf, "%d\n", (data->adc_input[attr->index] *
- ads7828_lsb_resol)/1000);
-}
+ unsigned int value = DIV_ROUND_CLOSEST(data->adc_input[attr->index] *
+ data->lsb_resol, 1000);
-#define in_reg(offset)\
-static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO, show_in,\
- NULL, offset)
+ return sprintf(buf, "%d\n", value);
+}
-in_reg(0);
-in_reg(1);
-in_reg(2);
-in_reg(3);
-in_reg(4);
-in_reg(5);
-in_reg(6);
-in_reg(7);
+static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ads7828_show_in, NULL, 0);
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ads7828_show_in, NULL, 1);
+static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ads7828_show_in, NULL, 2);
+static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ads7828_show_in, NULL, 3);
+static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ads7828_show_in, NULL, 4);
+static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, ads7828_show_in, NULL, 5);
+static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, ads7828_show_in, NULL, 6);
+static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, ads7828_show_in, NULL, 7);
static struct attribute *ads7828_attributes[] = {
&sensor_dev_attr_in0_input.dev_attr.attr,
static int ads7828_remove(struct i2c_client *client)
{
struct ads7828_data *data = i2c_get_clientdata(client);
+
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &ads7828_group);
- return 0;
-}
-
-static const struct i2c_device_id ads7828_id[] = {
- { "ads7828", 0 },
- { }
-};
-MODULE_DEVICE_TABLE(i2c, ads7828_id);
-
-/* This is the driver that will be inserted */
-static struct i2c_driver ads7828_driver = {
- .class = I2C_CLASS_HWMON,
- .driver = {
- .name = "ads7828",
- },
- .probe = ads7828_probe,
- .remove = ads7828_remove,
- .id_table = ads7828_id,
- .detect = ads7828_detect,
- .address_list = normal_i2c,
-};
-
-/* Return 0 if detection is successful, -ENODEV otherwise */
-static int ads7828_detect(struct i2c_client *client,
- struct i2c_board_info *info)
-{
- struct i2c_adapter *adapter = client->adapter;
- int ch;
-
- /* Check we have a valid client */
- if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA))
- return -ENODEV;
-
- /*
- * Now, we do the remaining detection. There is no identification
- * dedicated register so attempt to sanity check using knowledge of
- * the chip
- * - Read from the 8 channel addresses
- * - Check the top 4 bits of each result are not set (12 data bits)
- */
- for (ch = 0; ch < ADS7828_NCH; ch++) {
- u16 in_data;
- u8 cmd = channel_cmd_byte(ch);
- in_data = i2c_smbus_read_word_swapped(client, cmd);
- if (in_data & 0xF000) {
- pr_debug("%s : Doesn't look like an ads7828 device\n",
- __func__);
- return -ENODEV;
- }
- }
-
- strlcpy(info->type, "ads7828", I2C_NAME_SIZE);
return 0;
}
static int ads7828_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
+ struct ads7828_platform_data *pdata = client->dev.platform_data;
struct ads7828_data *data;
int err;
if (!data)
return -ENOMEM;
+ if (pdata) {
+ data->diff_input = pdata->diff_input;
+ data->ext_vref = pdata->ext_vref;
+ if (data->ext_vref)
+ data->vref_mv = pdata->vref_mv;
+ }
+
+ /* Bound Vref with min/max values if it was provided */
+ if (data->vref_mv)
+ data->vref_mv = SENSORS_LIMIT(data->vref_mv,
+ ADS7828_EXT_VREF_MV_MIN,
+ ADS7828_EXT_VREF_MV_MAX);
+ else
+ data->vref_mv = ADS7828_INT_VREF_MV;
+
+ data->lsb_resol = DIV_ROUND_CLOSEST(data->vref_mv * 1000, 4096);
+
+ data->cmd_byte = data->ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3;
+ if (!data->diff_input)
+ data->cmd_byte |= ADS7828_CMD_SD_SE;
+
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
- /* Register sysfs hooks */
err = sysfs_create_group(&client->dev.kobj, &ads7828_group);
if (err)
return err;
data->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
- goto exit_remove;
+ goto error;
}
return 0;
-exit_remove:
+error:
sysfs_remove_group(&client->dev.kobj, &ads7828_group);
return err;
}
-static int __init sensors_ads7828_init(void)
-{
- /* Initialize the command byte according to module parameters */
- ads7828_cmd_byte = se_input ?
- ADS7828_CMD_SD_SE : ADS7828_CMD_SD_DIFF;
- ads7828_cmd_byte |= int_vref ?
- ADS7828_CMD_PD3 : ADS7828_CMD_PD1;
+static const struct i2c_device_id ads7828_device_ids[] = {
+ { "ads7828", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ads7828_device_ids);
- /* Calculate the LSB resolution */
- ads7828_lsb_resol = (vref_mv*1000)/4096;
+static struct i2c_driver ads7828_driver = {
+ .driver = {
+ .name = "ads7828",
+ },
- return i2c_add_driver(&ads7828_driver);
-}
+ .id_table = ads7828_device_ids,
+ .probe = ads7828_probe,
+ .remove = ads7828_remove,
+};
-static void __exit sensors_ads7828_exit(void)
-{
- i2c_del_driver(&ads7828_driver);
-}
+module_i2c_driver(ads7828_driver);
-MODULE_AUTHOR("Steve Hardy <shardy@redhat.com>");
-MODULE_DESCRIPTION("ADS7828 driver");
MODULE_LICENSE("GPL");
-
-module_init(sensors_ads7828_init);
-module_exit(sensors_ads7828_exit);
+MODULE_AUTHOR("Steve Hardy <shardy@redhat.com>");
+MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter");
projects / karo-tx-linux.git / commitdiff