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Steve Hardy5812f922008-01-22 23:00:02 +00001/*
Guillaume Roguez0962e0f2012-10-03 16:54:08 -04002 * ads7828.c - driver for TI ADS7828 8-channel A/D converter and compatibles
Guenter Roeckd13d6232012-01-19 11:02:14 -08003 * (C) 2007 EADS Astrium
4 *
5 * This driver is based on the lm75 and other lm_sensors/hwmon drivers
6 *
7 * Written by Steve Hardy <shardy@redhat.com>
8 *
Guillaume Roguez0962e0f2012-10-03 16:54:08 -04009 * ADS7830 support, by Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
10 *
Vivien Didelot46d78462012-10-03 16:54:07 -040011 * For further information, see the Documentation/hwmon/ads7828 file.
Guenter Roeckd13d6232012-01-19 11:02:14 -080012 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 */
Steve Hardy5812f922008-01-22 23:00:02 +000027
Vivien Didelot46d78462012-10-03 16:54:07 -040028#include <linux/err.h>
Steve Hardy5812f922008-01-22 23:00:02 +000029#include <linux/hwmon.h>
30#include <linux/hwmon-sysfs.h>
Vivien Didelot46d78462012-10-03 16:54:07 -040031#include <linux/i2c.h>
32#include <linux/init.h>
Vivien Didelot46d78462012-10-03 16:54:07 -040033#include <linux/module.h>
Vivien Didelot46d78462012-10-03 16:54:07 -040034#include <linux/platform_data/ads7828.h>
Guenter Roeckbea0bab2015-01-16 10:08:27 -080035#include <linux/regmap.h>
Vivien Didelot46d78462012-10-03 16:54:07 -040036#include <linux/slab.h>
Steve Hardy5812f922008-01-22 23:00:02 +000037
38/* The ADS7828 registers */
Vivien Didelot46d78462012-10-03 16:54:07 -040039#define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */
40#define ADS7828_CMD_PD1 0x04 /* Internal vref OFF && A/D ON */
41#define ADS7828_CMD_PD3 0x0C /* Internal vref ON && A/D ON */
42#define ADS7828_INT_VREF_MV 2500 /* Internal vref is 2.5V, 2500mV */
43#define ADS7828_EXT_VREF_MV_MIN 50 /* External vref min value 0.05V */
44#define ADS7828_EXT_VREF_MV_MAX 5250 /* External vref max value 5.25V */
Steve Hardy5812f922008-01-22 23:00:02 +000045
Guillaume Roguez0962e0f2012-10-03 16:54:08 -040046/* List of supported devices */
47enum ads7828_chips { ads7828, ads7830 };
48
Vivien Didelot46d78462012-10-03 16:54:07 -040049/* Client specific data */
Steve Hardy5812f922008-01-22 23:00:02 +000050struct ads7828_data {
Guenter Roeckbea0bab2015-01-16 10:08:27 -080051 struct regmap *regmap;
Vivien Didelot46d78462012-10-03 16:54:07 -040052 u8 cmd_byte; /* Command byte without channel bits */
53 unsigned int lsb_resol; /* Resolution of the ADC sample LSB */
Steve Hardy5812f922008-01-22 23:00:02 +000054};
55
Vivien Didelot46d78462012-10-03 16:54:07 -040056/* Command byte C2,C1,C0 - see datasheet */
57static inline u8 ads7828_cmd_byte(u8 cmd, int ch)
Steve Hardy5812f922008-01-22 23:00:02 +000058{
Vivien Didelot46d78462012-10-03 16:54:07 -040059 return cmd | (((ch >> 1) | (ch & 0x01) << 2) << 4);
Steve Hardy5812f922008-01-22 23:00:02 +000060}
61
Steve Hardy5812f922008-01-22 23:00:02 +000062/* sysfs callback function */
Vivien Didelot46d78462012-10-03 16:54:07 -040063static ssize_t ads7828_show_in(struct device *dev, struct device_attribute *da,
64 char *buf)
Steve Hardy5812f922008-01-22 23:00:02 +000065{
66 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
Guenter Roeckbea0bab2015-01-16 10:08:27 -080067 struct ads7828_data *data = dev_get_drvdata(dev);
68 u8 cmd = ads7828_cmd_byte(data->cmd_byte, attr->index);
69 unsigned int regval;
70 int err;
Vivien Didelot46d78462012-10-03 16:54:07 -040071
Guenter Roeckbea0bab2015-01-16 10:08:27 -080072 err = regmap_read(data->regmap, cmd, &regval);
73 if (err < 0)
74 return err;
75
76 return sprintf(buf, "%d\n",
77 DIV_ROUND_CLOSEST(regval * data->lsb_resol, 1000));
Steve Hardy5812f922008-01-22 23:00:02 +000078}
79
Vivien Didelot46d78462012-10-03 16:54:07 -040080static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ads7828_show_in, NULL, 0);
81static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ads7828_show_in, NULL, 1);
82static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ads7828_show_in, NULL, 2);
83static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ads7828_show_in, NULL, 3);
84static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ads7828_show_in, NULL, 4);
85static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, ads7828_show_in, NULL, 5);
86static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, ads7828_show_in, NULL, 6);
87static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, ads7828_show_in, NULL, 7);
Steve Hardy5812f922008-01-22 23:00:02 +000088
Axel Linf82b2c32014-06-17 15:38:23 +080089static struct attribute *ads7828_attrs[] = {
Steve Hardy5812f922008-01-22 23:00:02 +000090 &sensor_dev_attr_in0_input.dev_attr.attr,
91 &sensor_dev_attr_in1_input.dev_attr.attr,
92 &sensor_dev_attr_in2_input.dev_attr.attr,
93 &sensor_dev_attr_in3_input.dev_attr.attr,
94 &sensor_dev_attr_in4_input.dev_attr.attr,
95 &sensor_dev_attr_in5_input.dev_attr.attr,
96 &sensor_dev_attr_in6_input.dev_attr.attr,
97 &sensor_dev_attr_in7_input.dev_attr.attr,
98 NULL
99};
100
Axel Linf82b2c32014-06-17 15:38:23 +0800101ATTRIBUTE_GROUPS(ads7828);
Steve Hardy5812f922008-01-22 23:00:02 +0000102
Guenter Roeckbea0bab2015-01-16 10:08:27 -0800103static const struct regmap_config ads2828_regmap_config = {
104 .reg_bits = 8,
105 .val_bits = 16,
106};
107
108static const struct regmap_config ads2830_regmap_config = {
109 .reg_bits = 8,
110 .val_bits = 8,
111};
112
Jean Delvare7347cb32008-07-16 19:30:10 +0200113static int ads7828_probe(struct i2c_client *client,
114 const struct i2c_device_id *id)
115{
Axel Linf82b2c32014-06-17 15:38:23 +0800116 struct device *dev = &client->dev;
117 struct ads7828_platform_data *pdata = dev_get_platdata(dev);
Jean Delvare7347cb32008-07-16 19:30:10 +0200118 struct ads7828_data *data;
Axel Linf82b2c32014-06-17 15:38:23 +0800119 struct device *hwmon_dev;
Guenter Roeck7f444bf2015-01-16 10:12:50 -0800120 unsigned int vref_mv = ADS7828_INT_VREF_MV;
121 bool diff_input = false;
122 bool ext_vref = false;
Steve Hardy5812f922008-01-22 23:00:02 +0000123
Axel Linf82b2c32014-06-17 15:38:23 +0800124 data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL);
Guenter Roeck34e3f7f2012-06-02 09:58:00 -0700125 if (!data)
126 return -ENOMEM;
Steve Hardy5812f922008-01-22 23:00:02 +0000127
Vivien Didelot46d78462012-10-03 16:54:07 -0400128 if (pdata) {
Guenter Roeck7f444bf2015-01-16 10:12:50 -0800129 diff_input = pdata->diff_input;
130 ext_vref = pdata->ext_vref;
131 if (ext_vref && pdata->vref_mv)
132 vref_mv = pdata->vref_mv;
Vivien Didelot46d78462012-10-03 16:54:07 -0400133 }
134
Guenter Roeck7f444bf2015-01-16 10:12:50 -0800135 /* Bound Vref with min/max values */
136 vref_mv = clamp_val(vref_mv, ADS7828_EXT_VREF_MV_MIN,
137 ADS7828_EXT_VREF_MV_MAX);
Vivien Didelot46d78462012-10-03 16:54:07 -0400138
Guillaume Roguez0962e0f2012-10-03 16:54:08 -0400139 /* ADS7828 uses 12-bit samples, while ADS7830 is 8-bit */
140 if (id->driver_data == ads7828) {
Guenter Roeck7f444bf2015-01-16 10:12:50 -0800141 data->lsb_resol = DIV_ROUND_CLOSEST(vref_mv * 1000, 4096);
Guenter Roeckbea0bab2015-01-16 10:08:27 -0800142 data->regmap = devm_regmap_init_i2c(client,
143 &ads2828_regmap_config);
Guillaume Roguez0962e0f2012-10-03 16:54:08 -0400144 } else {
Guenter Roeck7f444bf2015-01-16 10:12:50 -0800145 data->lsb_resol = DIV_ROUND_CLOSEST(vref_mv * 1000, 256);
Guenter Roeckbea0bab2015-01-16 10:08:27 -0800146 data->regmap = devm_regmap_init_i2c(client,
147 &ads2830_regmap_config);
Guillaume Roguez0962e0f2012-10-03 16:54:08 -0400148 }
Vivien Didelot46d78462012-10-03 16:54:07 -0400149
Axel Lind9ef72c2015-02-10 18:24:07 +0800150 if (IS_ERR(data->regmap))
151 return PTR_ERR(data->regmap);
152
Guenter Roeck7f444bf2015-01-16 10:12:50 -0800153 data->cmd_byte = ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3;
154 if (!diff_input)
Vivien Didelot46d78462012-10-03 16:54:07 -0400155 data->cmd_byte |= ADS7828_CMD_SD_SE;
156
Axel Linf82b2c32014-06-17 15:38:23 +0800157 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
158 data,
159 ads7828_groups);
160 return PTR_ERR_OR_ZERO(hwmon_dev);
Steve Hardy5812f922008-01-22 23:00:02 +0000161}
162
Vivien Didelot46d78462012-10-03 16:54:07 -0400163static const struct i2c_device_id ads7828_device_ids[] = {
Guillaume Roguez0962e0f2012-10-03 16:54:08 -0400164 { "ads7828", ads7828 },
165 { "ads7830", ads7830 },
Vivien Didelot46d78462012-10-03 16:54:07 -0400166 { }
167};
168MODULE_DEVICE_TABLE(i2c, ads7828_device_ids);
Steve Hardy5812f922008-01-22 23:00:02 +0000169
Vivien Didelot46d78462012-10-03 16:54:07 -0400170static struct i2c_driver ads7828_driver = {
171 .driver = {
172 .name = "ads7828",
173 },
Steve Hardy5812f922008-01-22 23:00:02 +0000174
Vivien Didelot46d78462012-10-03 16:54:07 -0400175 .id_table = ads7828_device_ids,
176 .probe = ads7828_probe,
Vivien Didelot46d78462012-10-03 16:54:07 -0400177};
Steve Hardy5812f922008-01-22 23:00:02 +0000178
Vivien Didelot46d78462012-10-03 16:54:07 -0400179module_i2c_driver(ads7828_driver);
Steve Hardy5812f922008-01-22 23:00:02 +0000180
Steve Hardy5812f922008-01-22 23:00:02 +0000181MODULE_LICENSE("GPL");
Vivien Didelot46d78462012-10-03 16:54:07 -0400182MODULE_AUTHOR("Steve Hardy <shardy@redhat.com>");
Guillaume Roguez0962e0f2012-10-03 16:54:08 -0400183MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter and compatibles");