drivers/hwmon/pmbus/mp5990.c

   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"},
 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 <[email protected]>");
 177 MODULE_DESCRIPTION("PMBus driver for MP5990 HSC");
 178 MODULE_LICENSE("GPL");
 179 MODULE_IMPORT_NS("PMBUS");