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1/*
2 * Hardware monitoring driver for ZL6100 and compatibles
3 *
4 * Copyright (c) 2011 Ericsson AB.
5 *
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.
10 *
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.
15 *
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.
19 */
20
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>
29#include "pmbus.h"
30
31enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105,
32 zl9101, zl9117 };
33
34struct zl6100_data {
35 int id;
36 ktime_t access; /* chip access time */
37 int delay; /* Delay between chip accesses in uS */
38 struct pmbus_driver_info info;
39};
40
41#define to_zl6100_data(x) container_of(x, struct zl6100_data, info)
42
43#define ZL6100_MFR_CONFIG 0xd0
44#define ZL6100_DEVICE_ID 0xe4
45
46#define ZL6100_MFR_XTEMP_ENABLE (1 << 7)
47
48#define ZL6100_WAIT_TIME 1000 /* uS */
49
50static ushort delay = ZL6100_WAIT_TIME;
51module_param(delay, ushort, 0644);
52MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");
53
54/* Some chips need a delay between accesses */
55static inline void zl6100_wait(const struct zl6100_data *data)
56{
57 if (data->delay) {
58 s64 delta = ktime_us_delta(ktime_get(), data->access);
59 if (delta < data->delay)
60 udelay(data->delay - delta);
61 }
62}
63
64static int zl6100_read_word_data(struct i2c_client *client, int page, int reg)
65{
66 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
67 struct zl6100_data *data = to_zl6100_data(info);
68 int ret;
69
70 if (page || reg >= PMBUS_VIRT_BASE)
71 return -ENXIO;
72
73 if (data->id == zl2005) {
74 /*
75 * Limit register detection is not reliable on ZL2005.
76 * Make sure registers are not erroneously detected.
77 */
78 switch (reg) {
79 case PMBUS_VOUT_OV_WARN_LIMIT:
80 case PMBUS_VOUT_UV_WARN_LIMIT:
81 case PMBUS_IOUT_OC_WARN_LIMIT:
82 return -ENXIO;
83 }
84 }
85
86 zl6100_wait(data);
87 ret = pmbus_read_word_data(client, page, reg);
88 data->access = ktime_get();
89
90 return ret;
91}
92
93static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
94{
95 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
96 struct zl6100_data *data = to_zl6100_data(info);
97 int ret;
98
99 if (page > 0)
100 return -ENXIO;
101
102 zl6100_wait(data);
103 ret = pmbus_read_byte_data(client, page, reg);
104 data->access = ktime_get();
105
106 return ret;
107}
108
109static int zl6100_write_word_data(struct i2c_client *client, int page, int reg,
110 u16 word)
111{
112 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
113 struct zl6100_data *data = to_zl6100_data(info);
114 int ret;
115
116 if (page || reg >= PMBUS_VIRT_BASE)
117 return -ENXIO;
118
119 zl6100_wait(data);
120 ret = pmbus_write_word_data(client, page, reg, word);
121 data->access = ktime_get();
122
123 return ret;
124}
125
126static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
127{
128 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
129 struct zl6100_data *data = to_zl6100_data(info);
130 int ret;
131
132 if (page > 0)
133 return -ENXIO;
134
135 zl6100_wait(data);
136 ret = pmbus_write_byte(client, page, value);
137 data->access = ktime_get();
138
139 return ret;
140}
141
142static const struct i2c_device_id zl6100_id[] = {
143 {"bmr450", zl2005},
144 {"bmr451", zl2005},
145 {"bmr462", zl2008},
146 {"bmr463", zl2008},
147 {"bmr464", zl2008},
148 {"zl2004", zl2004},
149 {"zl2005", zl2005},
150 {"zl2006", zl2006},
151 {"zl2008", zl2008},
152 {"zl2105", zl2105},
153 {"zl2106", zl2106},
154 {"zl6100", zl6100},
155 {"zl6105", zl6105},
156 {"zl9101", zl9101},
157 {"zl9117", zl9117},
158 { }
159};
160MODULE_DEVICE_TABLE(i2c, zl6100_id);
161
162static int zl6100_probe(struct i2c_client *client,
163 const struct i2c_device_id *id)
164{
165 int ret;
166 struct zl6100_data *data;
167 struct pmbus_driver_info *info;
168 u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
169 const struct i2c_device_id *mid;
170
171 if (!i2c_check_functionality(client->adapter,
172 I2C_FUNC_SMBUS_READ_WORD_DATA
173 | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
174 return -ENODEV;
175
176 ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
177 device_id);
178 if (ret < 0) {
179 dev_err(&client->dev, "Failed to read device ID\n");
180 return ret;
181 }
182 device_id[ret] = '\0';
183 dev_info(&client->dev, "Device ID %s\n", device_id);
184
185 mid = NULL;
186 for (mid = zl6100_id; mid->name[0]; mid++) {
187 if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
188 break;
189 }
190 if (!mid->name[0]) {
191 dev_err(&client->dev, "Unsupported device\n");
192 return -ENODEV;
193 }
194 if (id->driver_data != mid->driver_data)
195 dev_notice(&client->dev,
196 "Device mismatch: Configured %s, detected %s\n",
197 id->name, mid->name);
198
199 data = devm_kzalloc(&client->dev, sizeof(struct zl6100_data),
200 GFP_KERNEL);
201 if (!data)
202 return -ENOMEM;
203
204 data->id = mid->driver_data;
205
206 /*
207 * According to information from the chip vendor, all currently
208 * supported chips are known to require a wait time between I2C
209 * accesses.
210 */
211 data->delay = delay;
212
213 /*
214 * Since there was a direct I2C device access above, wait before
215 * accessing the chip again.
216 */
217 data->access = ktime_get();
218 zl6100_wait(data);
219
220 info = &data->info;
221
222 info->pages = 1;
223 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
224 | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
225 | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
226 | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
227
228 ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG);
229 if (ret < 0)
230 return ret;
231
232 if (ret & ZL6100_MFR_XTEMP_ENABLE)
233 info->func[0] |= PMBUS_HAVE_TEMP2;
234
235 data->access = ktime_get();
236 zl6100_wait(data);
237
238 info->read_word_data = zl6100_read_word_data;
239 info->read_byte_data = zl6100_read_byte_data;
240 info->write_word_data = zl6100_write_word_data;
241 info->write_byte = zl6100_write_byte;
242
243 return pmbus_do_probe(client, mid, info);
244}
245
246static struct i2c_driver zl6100_driver = {
247 .driver = {
248 .name = "zl6100",
249 },
250 .probe = zl6100_probe,
251 .remove = pmbus_do_remove,
252 .id_table = zl6100_id,
253};
254
255module_i2c_driver(zl6100_driver);
256
257MODULE_AUTHOR("Guenter Roeck");
258MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
259MODULE_LICENSE("GPL");