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 31 enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105 }; 32 33 struct zl6100_data { 34 int id; 35 ktime_t access; /* chip access time */ 36 struct pmbus_driver_info info; 37 }; 38 39 #define to_zl6100_data(x) container_of(x, struct zl6100_data, info) 40 41 #define ZL6100_MFR_CONFIG 0xd0 42 #define ZL6100_DEVICE_ID 0xe4 43 44 #define ZL6100_MFR_XTEMP_ENABLE (1 << 7) 45 46 #define ZL6100_WAIT_TIME 1000 /* uS */ 47 48 static ushort delay = ZL6100_WAIT_TIME; 49 module_param(delay, ushort, 0644); 50 MODULE_PARM_DESC(delay, "Delay between chip accesses in uS"); 51 52 /* Some chips need a delay between accesses */ 53 static inline void zl6100_wait(const struct zl6100_data *data) 54 { 55 if (delay) { 56 s64 delta = ktime_us_delta(ktime_get(), data->access); 57 if (delta < delay) 58 udelay(delay - delta); 59 } 60 } 61 62 static int zl6100_read_word_data(struct i2c_client *client, int page, int reg) 63 { 64 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 65 struct zl6100_data *data = to_zl6100_data(info); 66 int ret; 67 68 if (page || reg >= PMBUS_VIRT_BASE) 69 return -ENXIO; 70 71 if (data->id == zl2005) { 72 /* 73 * Limit register detection is not reliable on ZL2005. 74 * Make sure registers are not erroneously detected. 75 */ 76 switch (reg) { 77 case PMBUS_VOUT_OV_WARN_LIMIT: 78 case PMBUS_VOUT_UV_WARN_LIMIT: 79 case PMBUS_IOUT_OC_WARN_LIMIT: 80 return -ENXIO; 81 } 82 } 83 84 zl6100_wait(data); 85 ret = pmbus_read_word_data(client, page, reg); 86 data->access = ktime_get(); 87 88 return ret; 89 } 90 91 static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg) 92 { 93 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 94 struct zl6100_data *data = to_zl6100_data(info); 95 int ret; 96 97 if (page > 0) 98 return -ENXIO; 99 100 zl6100_wait(data); 101 ret = pmbus_read_byte_data(client, page, reg); 102 data->access = ktime_get(); 103 104 return ret; 105 } 106 107 static int zl6100_write_word_data(struct i2c_client *client, int page, int reg, 108 u16 word) 109 { 110 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 111 struct zl6100_data *data = to_zl6100_data(info); 112 int ret; 113 114 if (page || reg >= PMBUS_VIRT_BASE) 115 return -ENXIO; 116 117 zl6100_wait(data); 118 ret = pmbus_write_word_data(client, page, reg, word); 119 data->access = ktime_get(); 120 121 return ret; 122 } 123 124 static int zl6100_write_byte(struct i2c_client *client, int page, u8 value) 125 { 126 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 127 struct zl6100_data *data = to_zl6100_data(info); 128 int ret; 129 130 if (page > 0) 131 return -ENXIO; 132 133 zl6100_wait(data); 134 ret = pmbus_write_byte(client, page, value); 135 data->access = ktime_get(); 136 137 return ret; 138 } 139 140 static const struct i2c_device_id zl6100_id[] = { 141 {"bmr450", zl2005}, 142 {"bmr451", zl2005}, 143 {"bmr462", zl2008}, 144 {"bmr463", zl2008}, 145 {"bmr464", zl2008}, 146 {"zl2004", zl2004}, 147 {"zl2005", zl2005}, 148 {"zl2006", zl2006}, 149 {"zl2008", zl2008}, 150 {"zl2105", zl2105}, 151 {"zl2106", zl2106}, 152 {"zl6100", zl6100}, 153 {"zl6105", zl6105}, 154 { } 155 }; 156 MODULE_DEVICE_TABLE(i2c, zl6100_id); 157 158 static int zl6100_probe(struct i2c_client *client, 159 const struct i2c_device_id *id) 160 { 161 int ret; 162 struct zl6100_data *data; 163 struct pmbus_driver_info *info; 164 u8 device_id[I2C_SMBUS_BLOCK_MAX + 1]; 165 const struct i2c_device_id *mid; 166 167 if (!i2c_check_functionality(client->adapter, 168 I2C_FUNC_SMBUS_READ_WORD_DATA 169 | I2C_FUNC_SMBUS_READ_BLOCK_DATA)) 170 return -ENODEV; 171 172 ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID, 173 device_id); 174 if (ret < 0) { 175 dev_err(&client->dev, "Failed to read device ID\n"); 176 return ret; 177 } 178 device_id[ret] = '\0'; 179 dev_info(&client->dev, "Device ID %s\n", device_id); 180 181 mid = NULL; 182 for (mid = zl6100_id; mid->name[0]; mid++) { 183 if (!strncasecmp(mid->name, device_id, strlen(mid->name))) 184 break; 185 } 186 if (!mid->name[0]) { 187 dev_err(&client->dev, "Unsupported device\n"); 188 return -ENODEV; 189 } 190 if (id->driver_data != mid->driver_data) 191 dev_notice(&client->dev, 192 "Device mismatch: Configured %s, detected %s\n", 193 id->name, mid->name); 194 195 data = kzalloc(sizeof(struct zl6100_data), GFP_KERNEL); 196 if (!data) 197 return -ENOMEM; 198 199 data->id = mid->driver_data; 200 201 /* 202 * ZL2005, ZL2008, ZL2105, and ZL6100 are known to require a wait time 203 * between I2C accesses. ZL2004 and ZL6105 are known to be safe. 204 * Other chips have not yet been tested. 205 * 206 * Only clear the wait time for chips known to be safe. The wait time 207 * can be cleared later for additional chips if tests show that it 208 * is not needed (in other words, better be safe than sorry). 209 */ 210 if (data->id == zl2004 || data->id == zl6105) 211 delay = 0; 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 goto err_mem; 231 if (ret & ZL6100_MFR_XTEMP_ENABLE) 232 info->func[0] |= PMBUS_HAVE_TEMP2; 233 234 data->access = ktime_get(); 235 zl6100_wait(data); 236 237 info->read_word_data = zl6100_read_word_data; 238 info->read_byte_data = zl6100_read_byte_data; 239 info->write_word_data = zl6100_write_word_data; 240 info->write_byte = zl6100_write_byte; 241 242 ret = pmbus_do_probe(client, mid, info); 243 if (ret) 244 goto err_mem; 245 return 0; 246 247 err_mem: 248 kfree(data); 249 return ret; 250 } 251 252 static int zl6100_remove(struct i2c_client *client) 253 { 254 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 255 const struct zl6100_data *data = to_zl6100_data(info); 256 257 pmbus_do_remove(client); 258 kfree(data); 259 return 0; 260 } 261 262 static struct i2c_driver zl6100_driver = { 263 .driver = { 264 .name = "zl6100", 265 }, 266 .probe = zl6100_probe, 267 .remove = zl6100_remove, 268 .id_table = zl6100_id, 269 }; 270 271 static int __init zl6100_init(void) 272 { 273 return i2c_add_driver(&zl6100_driver); 274 } 275 276 static void __exit zl6100_exit(void) 277 { 278 i2c_del_driver(&zl6100_driver); 279 } 280 281 MODULE_AUTHOR("Guenter Roeck"); 282 MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles"); 283 MODULE_LICENSE("GPL"); 284 module_init(zl6100_init); 285 module_exit(zl6100_exit); 286