1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Hardware monitoring driver for Analog Devices LT7182S 4 * 5 * Copyright (c) 2022 Guenter Roeck 6 * 7 */ 8 9 #include <linux/bits.h> 10 #include <linux/err.h> 11 #include <linux/i2c.h> 12 #include <linux/init.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/of.h> 16 #include "pmbus.h" 17 18 #define LT7182S_NUM_PAGES 2 19 20 #define MFR_READ_EXTVCC 0xcd 21 #define MFR_READ_ITH 0xce 22 #define MFR_CONFIG_ALL_LT7182S 0xd1 23 #define MFR_IOUT_PEAK 0xd7 24 #define MFR_ADC_CONTROL_LT7182S 0xd8 25 26 #define MFR_DEBUG_TELEMETRY BIT(0) 27 28 #define MFR_VOUT_PEAK 0xdd 29 #define MFR_VIN_PEAK 0xde 30 #define MFR_TEMPERATURE_1_PEAK 0xdf 31 #define MFR_CLEAR_PEAKS 0xe3 32 33 #define MFR_CONFIG_IEEE BIT(8) 34 35 static int lt7182s_read_word_data(struct i2c_client *client, int page, int phase, int reg) 36 { 37 int ret; 38 39 switch (reg) { 40 case PMBUS_VIRT_READ_VMON: 41 if (page == 0 || page == 1) 42 ret = pmbus_read_word_data(client, page, phase, MFR_READ_ITH); 43 else 44 ret = pmbus_read_word_data(client, 0, phase, MFR_READ_EXTVCC); 45 break; 46 case PMBUS_VIRT_READ_IOUT_MAX: 47 ret = pmbus_read_word_data(client, page, phase, MFR_IOUT_PEAK); 48 break; 49 case PMBUS_VIRT_READ_VOUT_MAX: 50 ret = pmbus_read_word_data(client, page, phase, MFR_VOUT_PEAK); 51 break; 52 case PMBUS_VIRT_READ_VIN_MAX: 53 ret = pmbus_read_word_data(client, page, phase, MFR_VIN_PEAK); 54 break; 55 case PMBUS_VIRT_READ_TEMP_MAX: 56 ret = pmbus_read_word_data(client, page, phase, MFR_TEMPERATURE_1_PEAK); 57 break; 58 case PMBUS_VIRT_RESET_VIN_HISTORY: 59 ret = (page == 0) ? 0 : -ENODATA; 60 break; 61 default: 62 ret = -ENODATA; 63 break; 64 } 65 return ret; 66 } 67 68 static int lt7182s_write_word_data(struct i2c_client *client, int page, int reg, u16 word) 69 { 70 int ret; 71 72 switch (reg) { 73 case PMBUS_VIRT_RESET_VIN_HISTORY: 74 ret = pmbus_write_byte(client, 0, MFR_CLEAR_PEAKS); 75 break; 76 default: 77 ret = -ENODATA; 78 break; 79 } 80 return ret; 81 } 82 83 static struct pmbus_driver_info lt7182s_info = { 84 .pages = LT7182S_NUM_PAGES, 85 .format[PSC_VOLTAGE_IN] = linear, 86 .format[PSC_VOLTAGE_OUT] = linear, 87 .format[PSC_CURRENT_IN] = linear, 88 .format[PSC_CURRENT_OUT] = linear, 89 .format[PSC_TEMPERATURE] = linear, 90 .format[PSC_POWER] = linear, 91 .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | 92 PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT | 93 PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT | 94 PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP, 95 .func[1] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | 96 PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT | 97 PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT | 98 PMBUS_HAVE_STATUS_INPUT, 99 .read_word_data = lt7182s_read_word_data, 100 .write_word_data = lt7182s_write_word_data, 101 }; 102 103 static int lt7182s_probe(struct i2c_client *client) 104 { 105 struct device *dev = &client->dev; 106 struct pmbus_driver_info *info; 107 u8 buf[I2C_SMBUS_BLOCK_MAX + 1]; 108 int ret; 109 110 if (!i2c_check_functionality(client->adapter, 111 I2C_FUNC_SMBUS_READ_BYTE_DATA | 112 I2C_FUNC_SMBUS_READ_WORD_DATA | 113 I2C_FUNC_SMBUS_READ_BLOCK_DATA)) 114 return -ENODEV; 115 116 ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf); 117 if (ret < 0) { 118 dev_err(dev, "Failed to read PMBUS_MFR_ID\n"); 119 return ret; 120 } 121 if (ret != 3 || strncmp(buf, "ADI", 3)) { 122 buf[ret] = '\0'; 123 dev_err(dev, "Manufacturer '%s' not supported\n", buf); 124 return -ENODEV; 125 } 126 127 ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf); 128 if (ret < 0) { 129 dev_err(dev, "Failed to read PMBUS_MFR_MODEL\n"); 130 return ret; 131 } 132 if (ret != 7 || strncmp(buf, "LT7182S", 7)) { 133 buf[ret] = '\0'; 134 dev_err(dev, "Model '%s' not supported\n", buf); 135 return -ENODEV; 136 } 137 138 info = devm_kmemdup(dev, <7182s_info, 139 sizeof(struct pmbus_driver_info), GFP_KERNEL); 140 if (!info) 141 return -ENOMEM; 142 143 /* Set data format to IEEE754 if configured */ 144 ret = i2c_smbus_read_word_data(client, MFR_CONFIG_ALL_LT7182S); 145 if (ret < 0) 146 return ret; 147 if (ret & MFR_CONFIG_IEEE) { 148 info->format[PSC_VOLTAGE_IN] = ieee754; 149 info->format[PSC_VOLTAGE_OUT] = ieee754; 150 info->format[PSC_CURRENT_IN] = ieee754; 151 info->format[PSC_CURRENT_OUT] = ieee754; 152 info->format[PSC_TEMPERATURE] = ieee754; 153 info->format[PSC_POWER] = ieee754; 154 } 155 156 /* Enable VMON output if configured */ 157 ret = i2c_smbus_read_byte_data(client, MFR_ADC_CONTROL_LT7182S); 158 if (ret < 0) 159 return ret; 160 if (ret & MFR_DEBUG_TELEMETRY) { 161 info->pages = 3; 162 info->func[0] |= PMBUS_HAVE_VMON; 163 info->func[1] |= PMBUS_HAVE_VMON; 164 info->func[2] = PMBUS_HAVE_VMON; 165 } 166 167 return pmbus_do_probe(client, info); 168 } 169 170 static const struct i2c_device_id lt7182s_id[] = { 171 { "lt7182s", 0 }, 172 {} 173 }; 174 MODULE_DEVICE_TABLE(i2c, lt7182s_id); 175 176 static const struct of_device_id __maybe_unused lt7182s_of_match[] = { 177 { .compatible = "adi,lt7182s" }, 178 {} 179 }; 180 181 static struct i2c_driver lt7182s_driver = { 182 .driver = { 183 .name = "lt7182s", 184 .of_match_table = of_match_ptr(lt7182s_of_match), 185 }, 186 .probe_new = lt7182s_probe, 187 .id_table = lt7182s_id, 188 }; 189 190 module_i2c_driver(lt7182s_driver); 191 192 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); 193 MODULE_DESCRIPTION("PMBus driver for Analog Devices LT7182S"); 194 MODULE_LICENSE("GPL"); 195 MODULE_IMPORT_NS(PMBUS); 196