Patched in Tegra support.

1 files changed, 180 insertions, 127 deletions

diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c
index 409b5c16def..c42c5a69a66 100644
--- a/drivers/hwmon/ads7828.c
+++ b/drivers/hwmon/ads7828.c
@@ -1,72 +1,92 @@
 /*
- * 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
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
+        ads7828.c - lm_sensors driver for ads7828 12-bit 8-channel ADC
+        (C) 2007 EADS Astrium
 
-#include <linux/err.h>
-#include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
-#include <linux/i2c.h>
+        This driver is based on the lm75 and other lm_sensors/hwmon drivers
+
+        Written by Steve Hardy <shardy@redhat.com>
+
+        Datasheet available at: http://focus.ti.com/lit/ds/symlink/ads7828.pdf
+
+        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
+        the Free Software Foundation; either version 2 of the License, or
+        (at your option) any later version.
+
+        This program is distributed in the hope that it will be useful,
+        but WITHOUT ANY WARRANTY; without even the implied warranty of
+        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.    See the
+        GNU General Public License for more details.
+
+        You should have received a copy of the GNU General Public License
+        along with this program; if not, write to the Free Software
+        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/module.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
 #include <linux/mutex.h>
-#include <linux/platform_data/ads7828.h>
-#include <linux/slab.h>
 
 /* The ADS7828 registers */
-#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 */
-
-/* List of supported devices */
-enum ads7828_chips { ads7828, ads7830 };
-
-/* Client specific data */
+#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 int se_input = 1; /* Default is SE, 0 == diff */
+static int 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 */
 struct ads7828_data {
         struct device *hwmon_dev;
-        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 */
-        s32 (*read_channel)(const struct i2c_client *client, u8 command);
+        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 */
 };
 
-/* Command byte C2,C1,C0 - see datasheet */
-static inline u8 ads7828_cmd_byte(u8 cmd, int ch)
+/* 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);
+
+/* The ADS7828 returns the 12-bit sample in two bytes,
+        these are read as a word then byte-swapped */
+static u16 ads7828_read_value(struct i2c_client *client, u8 reg)
 {
-        return cmd | (((ch >> 1) | (ch & 0x01) << 2) << 4);
+        return swab16(i2c_smbus_read_word_data(client, reg));
+}
+
+static inline u8 channel_cmd_byte(int ch)
+{
+        /* cmd byte C2,C1,C0 - see datasheet */
+        u8 cmd = (((ch>>1) | (ch&0x01)<<2)<<4);
+        cmd |= ads7828_cmd_byte;
+        return cmd;
 }
 
 /* Update data for the device (all 8 channels) */
@@ -83,11 +103,11 @@ static struct ads7828_data *ads7828_update_device(struct device *dev)
                 dev_dbg(&client->dev, "Starting ads7828 update\n");
 
                 for (ch = 0; ch < ADS7828_NCH; ch++) {
-                        u8 cmd = ads7828_cmd_byte(data->cmd_byte, ch);
-                        data->adc_input[ch] = data->read_channel(client, cmd);
+                        u8 cmd = channel_cmd_byte(ch);
+                        data->adc_input[ch] = ads7828_read_value(client, cmd);
                 }
                 data->last_updated = jiffies;
-                data->valid = true;
+                data->valid = 1;
         }
 
         mutex_unlock(&data->update_lock);
@@ -96,25 +116,28 @@ static struct ads7828_data *ads7828_update_device(struct device *dev)
 }
 
 /* sysfs callback function */
-static ssize_t ads7828_show_in(struct device *dev, struct device_attribute *da,
-                               char *buf)
+static ssize_t 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);
-        unsigned int value = DIV_ROUND_CLOSEST(data->adc_input[attr->index] *
-                                               data->lsb_resol, 1000);
-
-        return sprintf(buf, "%d\n", value);
+        /* Print value (in mV as specified in sysfs-interface documentation) */
+        return sprintf(buf, "%d\n", (data->adc_input[attr->index] *
+                ads7828_lsb_resol)/1000);
 }
 
-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);
+#define in_reg(offset)\
+static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO, show_in,\
+        NULL, offset)
+
+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 struct attribute *ads7828_attributes[] = {
         &sensor_dev_attr_in0_input.dev_attr.attr,
@@ -135,9 +158,60 @@ static const struct attribute_group ads7828_group = {
 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);
+        kfree(i2c_get_clientdata(client));
+        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 = ads7828_read_value(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;
 }
@@ -145,82 +219,61 @@ static int ads7828_remove(struct i2c_client *client)
 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;
 
-        data = devm_kzalloc(&client->dev, sizeof(struct ads7828_data),
-                            GFP_KERNEL);
-        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;
-
-        /* 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 = kzalloc(sizeof(struct ads7828_data), GFP_KERNEL);
+        if (!data) {
+                err = -ENOMEM;
+                goto exit;
         }
 
-        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;
+                goto exit_free;
 
         data->hwmon_dev = hwmon_device_register(&client->dev);
         if (IS_ERR(data->hwmon_dev)) {
                 err = PTR_ERR(data->hwmon_dev);
-                goto error;
+                goto exit_remove;
         }
 
         return 0;
 
-error:
+exit_remove:
         sysfs_remove_group(&client->dev.kobj, &ads7828_group);
+exit_free:
+        kfree(data);
+exit:
         return err;
 }
 
-static const struct i2c_device_id ads7828_device_ids[] = {
-        { "ads7828", ads7828 },
-        { "ads7830", ads7830 },
-        { }
-};
-MODULE_DEVICE_TABLE(i2c, ads7828_device_ids);
+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 struct i2c_driver ads7828_driver = {
-        .driver = {
-                .name = "ads7828",
-        },
+        /* Calculate the LSB resolution */
+        ads7828_lsb_resol = (vref_mv*1000)/4096;
 
-        .id_table = ads7828_device_ids,
-        .probe = ads7828_probe,
-        .remove = ads7828_remove,
-};
+        return i2c_add_driver(&ads7828_driver);
+}
 
-module_i2c_driver(ads7828_driver);
+static void __exit sensors_ads7828_exit(void)
+{
+        i2c_del_driver(&ads7828_driver);
+}
 
-MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Steve Hardy <shardy@redhat.com>");
-MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter and compatibles");
+MODULE_DESCRIPTION("ADS7828 driver");
+MODULE_LICENSE("GPL");
+
+module_init(sensors_ads7828_init);
+module_exit(sensors_ads7828_exit);