2 * Hardware monitoring driver for ZL6100 and compatibles
4 * Copyright (c) 2011 Ericsson AB.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/err.h>
25 #include <linux/slab.h>
26 #include <linux/i2c.h>
27 #include <linux/ktime.h>
28 #include <linux/delay.h>
31 enum chips { zl2004, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105 };
35 ktime_t access; /* chip access time */
36 int delay; /* Delay between chip accesses in uS */
37 struct pmbus_driver_info info;
40 #define to_zl6100_data(x) container_of(x, struct zl6100_data, info)
42 #define ZL6100_DEVICE_ID 0xe4
44 #define ZL6100_WAIT_TIME 1000 /* uS */
46 static ushort delay = ZL6100_WAIT_TIME;
47 module_param(delay, ushort, 0644);
48 MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");
50 /* Some chips need a delay between accesses */
51 static inline void zl6100_wait(const struct zl6100_data *data)
54 s64 delta = ktime_us_delta(ktime_get(), data->access);
55 if (delta < data->delay)
56 udelay(data->delay - delta);
60 static int zl6100_read_word_data(struct i2c_client *client, int page, int reg)
62 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
63 struct zl6100_data *data = to_zl6100_data(info);
66 if (page || reg >= PMBUS_VIRT_BASE)
70 ret = pmbus_read_word_data(client, page, reg);
71 data->access = ktime_get();
76 static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
78 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
79 struct zl6100_data *data = to_zl6100_data(info);
86 ret = pmbus_read_byte_data(client, page, reg);
87 data->access = ktime_get();
92 static int zl6100_write_word_data(struct i2c_client *client, int page, int reg,
95 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
96 struct zl6100_data *data = to_zl6100_data(info);
99 if (page || reg >= PMBUS_VIRT_BASE)
103 ret = pmbus_write_word_data(client, page, reg, word);
104 data->access = ktime_get();
109 static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
111 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
112 struct zl6100_data *data = to_zl6100_data(info);
119 ret = pmbus_write_byte(client, page, value);
120 data->access = ktime_get();
125 static const struct i2c_device_id zl6100_id[] = {
135 MODULE_DEVICE_TABLE(i2c, zl6100_id);
137 static int zl6100_probe(struct i2c_client *client,
138 const struct i2c_device_id *id)
141 struct zl6100_data *data;
142 struct pmbus_driver_info *info;
143 u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
144 const struct i2c_device_id *mid;
146 if (!i2c_check_functionality(client->adapter,
147 I2C_FUNC_SMBUS_READ_BYTE_DATA
148 | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
151 ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
154 dev_err(&client->dev, "Failed to read device ID\n");
157 device_id[ret] = '\0';
158 dev_info(&client->dev, "Device ID %s\n", device_id);
161 for (mid = zl6100_id; mid->name[0]; mid++) {
162 if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
166 dev_err(&client->dev, "Unsupported device\n");
169 if (id->driver_data != mid->driver_data)
170 dev_notice(&client->dev,
171 "Device mismatch: Configured %s, detected %s\n",
172 id->name, mid->name);
174 data = kzalloc(sizeof(struct zl6100_data), GFP_KERNEL);
178 data->id = mid->driver_data;
181 * ZL2008, ZL2105, and ZL6100 are known to require a wait time
182 * between I2C accesses. ZL2004 and ZL6105 are known to be safe.
184 * Only clear the wait time for chips known to be safe. The wait time
185 * can be cleared later for additional chips if tests show that it
186 * is not needed (in other words, better be safe than sorry).
189 if (data->id == zl2004 || data->id == zl6105)
193 * Since there was a direct I2C device access above, wait before
194 * accessing the chip again.
195 * Set the timestamp, wait, then set it again. This should provide
196 * enough buffer time to be safe.
198 data->access = ktime_get();
200 data->access = ktime_get();
205 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
206 | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
207 | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
208 | PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
210 info->read_word_data = zl6100_read_word_data;
211 info->read_byte_data = zl6100_read_byte_data;
212 info->write_word_data = zl6100_write_word_data;
213 info->write_byte = zl6100_write_byte;
215 ret = pmbus_do_probe(client, mid, info);
225 static int zl6100_remove(struct i2c_client *client)
227 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
228 const struct zl6100_data *data = to_zl6100_data(info);
230 pmbus_do_remove(client);
235 static struct i2c_driver zl6100_driver = {
239 .probe = zl6100_probe,
240 .remove = zl6100_remove,
241 .id_table = zl6100_id,
244 static int __init zl6100_init(void)
246 return i2c_add_driver(&zl6100_driver);
249 static void __exit zl6100_exit(void)
251 i2c_del_driver(&zl6100_driver);
254 MODULE_AUTHOR("Guenter Roeck");
255 MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
256 MODULE_LICENSE("GPL");
257 module_init(zl6100_init);
258 module_exit(zl6100_exit);