1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Driver for MPS MP5990 Hot-Swap Controller 4 */ 5 6 #include <linux/i2c.h> 7 #include <linux/module.h> 8 #include <linux/of_device.h> 9 #include "pmbus.h" 10 11 #define MP5990_EFUSE_CFG (0xC4) 12 #define MP5990_VOUT_FORMAT BIT(9) 13 14 struct mp5990_data { 15 struct pmbus_driver_info info; 16 u8 vout_mode; 17 u8 vout_linear_exponent; 18 }; 19 20 #define to_mp5990_data(x) container_of(x, struct mp5990_data, info) 21 22 static int mp5990_read_byte_data(struct i2c_client *client, int page, int reg) 23 { 24 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 25 struct mp5990_data *data = to_mp5990_data(info); 26 27 switch (reg) { 28 case PMBUS_VOUT_MODE: 29 if (data->vout_mode == linear) { 30 /* 31 * The VOUT format used by the chip is linear11, 32 * not linear16. Report that VOUT is in linear mode 33 * and return exponent value extracted while probing 34 * the chip. 35 */ 36 return data->vout_linear_exponent; 37 } 38 39 /* 40 * The datasheet does not support the VOUT command, 41 * but the device responds with a default value of 0x17. 42 * In the standard, 0x17 represents linear mode. 43 * Therefore, we should report that VOUT is in direct 44 * format when the chip is configured for it. 45 */ 46 return PB_VOUT_MODE_DIRECT; 47 48 default: 49 return -ENODATA; 50 } 51 } 52 53 static int mp5990_read_word_data(struct i2c_client *client, int page, 54 int phase, int reg) 55 { 56 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 57 struct mp5990_data *data = to_mp5990_data(info); 58 int ret; 59 s32 mantissa; 60 61 switch (reg) { 62 case PMBUS_READ_VOUT: 63 ret = pmbus_read_word_data(client, page, phase, reg); 64 if (ret < 0) 65 return ret; 66 /* 67 * Because the VOUT format used by the chip is linear11 and not 68 * linear16, we disregard bits[15:11]. The exponent is reported 69 * as part of the VOUT_MODE command. 70 */ 71 if (data->vout_mode == linear) { 72 mantissa = ((s16)((ret & 0x7ff) << 5)) >> 5; 73 ret = mantissa; 74 } 75 break; 76 default: 77 return -ENODATA; 78 } 79 80 return ret; 81 } 82 83 static struct pmbus_driver_info mp5990_info = { 84 .pages = 1, 85 .format[PSC_VOLTAGE_IN] = direct, 86 .format[PSC_VOLTAGE_OUT] = direct, 87 .format[PSC_CURRENT_OUT] = direct, 88 .format[PSC_POWER] = direct, 89 .format[PSC_TEMPERATURE] = direct, 90 .m[PSC_VOLTAGE_IN] = 32, 91 .b[PSC_VOLTAGE_IN] = 0, 92 .R[PSC_VOLTAGE_IN] = 0, 93 .m[PSC_VOLTAGE_OUT] = 32, 94 .b[PSC_VOLTAGE_OUT] = 0, 95 .R[PSC_VOLTAGE_OUT] = 0, 96 .m[PSC_CURRENT_OUT] = 16, 97 .b[PSC_CURRENT_OUT] = 0, 98 .R[PSC_CURRENT_OUT] = 0, 99 .m[PSC_POWER] = 1, 100 .b[PSC_POWER] = 0, 101 .R[PSC_POWER] = 0, 102 .m[PSC_TEMPERATURE] = 1, 103 .b[PSC_TEMPERATURE] = 0, 104 .R[PSC_TEMPERATURE] = 0, 105 .func[0] = 106 PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_PIN | 107 PMBUS_HAVE_TEMP | PMBUS_HAVE_IOUT | 108 PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP, 109 .read_byte_data = mp5990_read_byte_data, 110 .read_word_data = mp5990_read_word_data, 111 }; 112 113 static int mp5990_probe(struct i2c_client *client) 114 { 115 struct pmbus_driver_info *info; 116 struct mp5990_data *data; 117 int ret; 118 119 data = devm_kzalloc(&client->dev, sizeof(struct mp5990_data), 120 GFP_KERNEL); 121 if (!data) 122 return -ENOMEM; 123 124 memcpy(&data->info, &mp5990_info, sizeof(*info)); 125 info = &data->info; 126 127 /* Read Vout Config */ 128 ret = i2c_smbus_read_word_data(client, MP5990_EFUSE_CFG); 129 if (ret < 0) { 130 dev_err(&client->dev, "Can't get vout mode."); 131 return ret; 132 } 133 134 /* 135 * EFUSE_CFG (0xC4) bit9=1 is linear mode, bit=0 is direct mode. 136 */ 137 if (ret & MP5990_VOUT_FORMAT) { 138 data->vout_mode = linear; 139 data->info.format[PSC_VOLTAGE_IN] = linear; 140 data->info.format[PSC_VOLTAGE_OUT] = linear; 141 data->info.format[PSC_CURRENT_OUT] = linear; 142 data->info.format[PSC_POWER] = linear; 143 ret = i2c_smbus_read_word_data(client, PMBUS_READ_VOUT); 144 if (ret < 0) { 145 dev_err(&client->dev, "Can't get vout exponent."); 146 return ret; 147 } 148 data->vout_linear_exponent = (u8)((ret >> 11) & 0x1f); 149 } else { 150 data->vout_mode = direct; 151 } 152 return pmbus_do_probe(client, info); 153 } 154 155 static const struct of_device_id mp5990_of_match[] = { 156 { .compatible = "mps,mp5990" }, 157 {} 158 }; 159 160 static const struct i2c_device_id mp5990_id[] = { 161 {"mp5990", 0}, 162 { } 163 }; 164 MODULE_DEVICE_TABLE(i2c, mp5990_id); 165 166 static struct i2c_driver mp5990_driver = { 167 .driver = { 168 .name = "mp5990", 169 .of_match_table = mp5990_of_match, 170 }, 171 .probe = mp5990_probe, 172 .id_table = mp5990_id, 173 }; 174 module_i2c_driver(mp5990_driver); 175 176 MODULE_AUTHOR("Peter Yin <peter.yin@quantatw.com>"); 177 MODULE_DESCRIPTION("PMBus driver for MP5990 HSC"); 178 MODULE_LICENSE("GPL"); 179 MODULE_IMPORT_NS(PMBUS); 180