1 /* 2 * Hardware monitoring driver for ucd9200 series Digital PWM System Controllers 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/i2c/pmbus.h> 28 #include "pmbus.h" 29 30 #define UCD9200_PHASE_INFO 0xd2 31 #define UCD9200_DEVICE_ID 0xfd 32 33 enum chips { ucd9200, ucd9220, ucd9222, ucd9224, ucd9240, ucd9244, ucd9246, 34 ucd9248 }; 35 36 static const struct i2c_device_id ucd9200_id[] = { 37 {"ucd9200", ucd9200}, 38 {"ucd9220", ucd9220}, 39 {"ucd9222", ucd9222}, 40 {"ucd9224", ucd9224}, 41 {"ucd9240", ucd9240}, 42 {"ucd9244", ucd9244}, 43 {"ucd9246", ucd9246}, 44 {"ucd9248", ucd9248}, 45 {} 46 }; 47 MODULE_DEVICE_TABLE(i2c, ucd9200_id); 48 49 static int ucd9200_probe(struct i2c_client *client, 50 const struct i2c_device_id *id) 51 { 52 u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1]; 53 struct pmbus_driver_info *info; 54 const struct i2c_device_id *mid; 55 int i, j, ret; 56 57 if (!i2c_check_functionality(client->adapter, 58 I2C_FUNC_SMBUS_BYTE_DATA | 59 I2C_FUNC_SMBUS_BLOCK_DATA)) 60 return -ENODEV; 61 62 ret = i2c_smbus_read_block_data(client, UCD9200_DEVICE_ID, 63 block_buffer); 64 if (ret < 0) { 65 dev_err(&client->dev, "Failed to read device ID\n"); 66 return ret; 67 } 68 block_buffer[ret] = '\0'; 69 dev_info(&client->dev, "Device ID %s\n", block_buffer); 70 71 for (mid = ucd9200_id; mid->name[0]; mid++) { 72 if (!strncasecmp(mid->name, block_buffer, strlen(mid->name))) 73 break; 74 } 75 if (!mid->name[0]) { 76 dev_err(&client->dev, "Unsupported device\n"); 77 return -ENODEV; 78 } 79 if (id->driver_data != ucd9200 && id->driver_data != mid->driver_data) 80 dev_notice(&client->dev, 81 "Device mismatch: Configured %s, detected %s\n", 82 id->name, mid->name); 83 84 info = devm_kzalloc(&client->dev, sizeof(struct pmbus_driver_info), 85 GFP_KERNEL); 86 if (!info) 87 return -ENOMEM; 88 89 ret = i2c_smbus_read_block_data(client, UCD9200_PHASE_INFO, 90 block_buffer); 91 if (ret < 0) { 92 dev_err(&client->dev, "Failed to read phase information\n"); 93 return ret; 94 } 95 96 /* 97 * Calculate number of configured pages (rails) from PHASE_INFO 98 * register. 99 * Rails have to be sequential, so we can abort after finding 100 * the first unconfigured rail. 101 */ 102 info->pages = 0; 103 for (i = 0; i < ret; i++) { 104 if (!block_buffer[i]) 105 break; 106 info->pages++; 107 } 108 if (!info->pages) { 109 dev_err(&client->dev, "No rails configured\n"); 110 return -ENODEV; 111 } 112 dev_info(&client->dev, "%d rails configured\n", info->pages); 113 114 /* 115 * Set PHASE registers on all pages to 0xff to ensure that phase 116 * specific commands will apply to all phases of a given page (rail). 117 * This only affects the READ_IOUT and READ_TEMPERATURE2 registers. 118 * READ_IOUT will return the sum of currents of all phases of a rail, 119 * and READ_TEMPERATURE2 will return the maximum temperature detected 120 * for the the phases of the rail. 121 */ 122 for (i = 0; i < info->pages; i++) { 123 /* 124 * Setting PAGE & PHASE fails once in a while for no obvious 125 * reason, so we need to retry a couple of times. 126 */ 127 for (j = 0; j < 3; j++) { 128 ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i); 129 if (ret < 0) 130 continue; 131 ret = i2c_smbus_write_byte_data(client, PMBUS_PHASE, 132 0xff); 133 if (ret < 0) 134 continue; 135 break; 136 } 137 if (ret < 0) { 138 dev_err(&client->dev, 139 "Failed to initialize PHASE registers\n"); 140 return ret; 141 } 142 } 143 if (info->pages > 1) 144 i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0); 145 146 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT | 147 PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | 148 PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | 149 PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | 150 PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP | 151 PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP; 152 153 for (i = 1; i < info->pages; i++) 154 info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | 155 PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | 156 PMBUS_HAVE_POUT | 157 PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP; 158 159 /* ucd9240 supports a single fan */ 160 if (mid->driver_data == ucd9240) 161 info->func[0] |= PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12; 162 163 return pmbus_do_probe(client, mid, info); 164 } 165 166 /* This is the driver that will be inserted */ 167 static struct i2c_driver ucd9200_driver = { 168 .driver = { 169 .name = "ucd9200", 170 }, 171 .probe = ucd9200_probe, 172 .remove = pmbus_do_remove, 173 .id_table = ucd9200_id, 174 }; 175 176 module_i2c_driver(ucd9200_driver); 177 178 MODULE_AUTHOR("Guenter Roeck"); 179 MODULE_DESCRIPTION("PMBus driver for TI UCD922x, UCD924x"); 180 MODULE_LICENSE("GPL"); 181