drivers/hwmon/pmbus/tda38640.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Hardware monitoring driver for Infineon TDA38640
   4  *
   5  * Copyright (c) 2023 9elements GmbH
   6  *
   7  */
   8
   9 #include <linux/err.h>
  10 #include <linux/i2c.h>
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/regulator/driver.h>
  15 #include "pmbus.h"
  16
  17 static const struct regulator_desc __maybe_unused tda38640_reg_desc[] = {
  18         PMBUS_REGULATOR_ONE("vout"),
  19 };
  20
  21 struct tda38640_data {
  22         struct pmbus_driver_info info;
  23         u32 en_pin_lvl;
  24 };
  25
  26 #define to_tda38640_data(x)  container_of(x, struct tda38640_data, info)
  27
  28 /*
  29  * Map PB_ON_OFF_CONFIG_POLARITY_HIGH to PB_OPERATION_CONTROL_ON.
  30  */
  31 static int tda38640_read_byte_data(struct i2c_client *client, int page, int reg)
  32 {
  33         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
  34         struct tda38640_data *data = to_tda38640_data(info);
  35         int ret, on_off_config, enabled;
  36
  37         if (reg != PMBUS_OPERATION)
  38                 return -ENODATA;
  39
  40         ret = pmbus_read_byte_data(client, page, reg);
  41         if (ret < 0)
  42                 return ret;
  43
  44         on_off_config = pmbus_read_byte_data(client, page,
  45                                              PMBUS_ON_OFF_CONFIG);
  46         if (on_off_config < 0)
  47                 return on_off_config;
  48
  49         enabled = !!(on_off_config & PB_ON_OFF_CONFIG_POLARITY_HIGH);
  50
  51         enabled ^= data->en_pin_lvl;
  52         if (enabled)
  53                 ret &= ~PB_OPERATION_CONTROL_ON;
  54         else
  55                 ret |= PB_OPERATION_CONTROL_ON;
  56
  57         return ret;
  58 }
  59
  60 /*
  61  * Map PB_OPERATION_CONTROL_ON to PB_ON_OFF_CONFIG_POLARITY_HIGH.
  62  */
  63 static int tda38640_write_byte_data(struct i2c_client *client, int page,
  64                                     int reg, u8 byte)
  65 {
  66         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
  67         struct tda38640_data *data = to_tda38640_data(info);
  68         int enable, ret;
  69
  70         if (reg != PMBUS_OPERATION)
  71                 return -ENODATA;
  72
  73         enable = !!(byte & PB_OPERATION_CONTROL_ON);
  74
  75         byte &= ~PB_OPERATION_CONTROL_ON;
  76         ret = pmbus_write_byte_data(client, page, reg, byte);
  77         if (ret < 0)
  78                 return ret;
  79
  80         enable ^= data->en_pin_lvl;
  81
  82         return pmbus_update_byte_data(client, page, PMBUS_ON_OFF_CONFIG,
  83                                       PB_ON_OFF_CONFIG_POLARITY_HIGH,
  84                                       enable ? 0 : PB_ON_OFF_CONFIG_POLARITY_HIGH);
  85 }
  86
  87 static int svid_mode(struct i2c_client *client, struct tda38640_data *data)
  88 {
  89         /* PMBUS_MFR_READ(0xD0) + MTP Address offset */
  90         u8 write_buf[] = {0xd0, 0x44, 0x00};
  91         u8 read_buf[2];
  92         int ret, svid;
  93         bool off, reg_en_pin_pol;
  94
  95         struct i2c_msg msgs[2] = {
  96                 {
  97                         .addr = client->addr,
  98                         .flags = 0,
  99                         .buf = write_buf,
 100                         .len = sizeof(write_buf),
 101                 },
 102                 {
 103                         .addr = client->addr,
 104                         .flags = I2C_M_RD,
 105                         .buf = read_buf,
 106                         .len = sizeof(read_buf),
 107                 }
 108         };
 109
 110         ret = i2c_transfer(client->adapter, msgs, 2);
 111         if (ret < 0) {
 112                 dev_err(&client->dev, "i2c_transfer failed. %d", ret);
 113                 return ret;
 114         }
 115
 116         /*
 117          * 0x44[15] determines PMBus Operating Mode
 118          * If bit is set then it is SVID mode.
 119          */
 120         svid = !!(read_buf[1] & BIT(7));
 121
 122         /*
 123          * Determine EN pin level for use in SVID mode.
 124          * This is done with help of STATUS_BYTE bit 6(OFF) & ON_OFF_CONFIG bit 2(EN pin polarity).
 125          */
 126         if (svid) {
 127                 ret = i2c_smbus_read_byte_data(client, PMBUS_STATUS_BYTE);
 128                 if (ret < 0)
 129                         return ret;
 130                 off = !!(ret & PB_STATUS_OFF);
 131
 132                 ret = i2c_smbus_read_byte_data(client, PMBUS_ON_OFF_CONFIG);
 133                 if (ret < 0)
 134                         return ret;
 135                 reg_en_pin_pol = !!(ret & PB_ON_OFF_CONFIG_POLARITY_HIGH);
 136                 data->en_pin_lvl = off ^ reg_en_pin_pol;
 137         }
 138
 139         return svid;
 140 }
 141
 142 static struct pmbus_driver_info tda38640_info = {
 143         .pages = 1,
 144         .format[PSC_VOLTAGE_IN] = linear,
 145         .format[PSC_VOLTAGE_OUT] = linear,
 146         .format[PSC_CURRENT_OUT] = linear,
 147         .format[PSC_CURRENT_IN] = linear,
 148         .format[PSC_POWER] = linear,
 149         .format[PSC_TEMPERATURE] = linear,
 150         .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
 151             | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
 152             | PMBUS_HAVE_IIN
 153             | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 154             | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 155             | PMBUS_HAVE_POUT | PMBUS_HAVE_PIN,
 156 #if IS_ENABLED(CONFIG_SENSORS_TDA38640_REGULATOR)
 157         .num_regulators = 1,
 158         .reg_desc = tda38640_reg_desc,
 159 #endif
 160 };
 161
 162 static int tda38640_probe(struct i2c_client *client)
 163 {
 164         struct tda38640_data *data;
 165         int svid;
 166
 167         data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
 168         if (!data)
 169                 return -ENOMEM;
 170         memcpy(&data->info, &tda38640_info, sizeof(tda38640_info));
 171
 172         if (IS_ENABLED(CONFIG_SENSORS_TDA38640_REGULATOR) &&
 173             of_property_read_bool(client->dev.of_node, "infineon,en-pin-fixed-level")) {
 174                 svid = svid_mode(client, data);
 175                 if (svid < 0) {
 176                         dev_err_probe(&client->dev, svid, "Could not determine operating mode.");
 177                         return svid;
 178                 }
 179
 180                 /*
 181                  * Apply ON_OFF_CONFIG workaround as enabling the regulator using the
 182                  * OPERATION register doesn't work in SVID mode.
 183                  *
 184                  * One should configure PMBUS_ON_OFF_CONFIG here, but
 185                  * PB_ON_OFF_CONFIG_POWERUP_CONTROL and PB_ON_OFF_CONFIG_EN_PIN_REQ
 186                  * are ignored by the device.
 187                  * Only PB_ON_OFF_CONFIG_POLARITY_HIGH has an effect.
 188                  */
 189                 if (svid) {
 190                         data->info.read_byte_data = tda38640_read_byte_data;
 191                         data->info.write_byte_data = tda38640_write_byte_data;
 192                 }
 193         }
 194         return pmbus_do_probe(client, &data->info);
 195 }
 196
 197 static const struct i2c_device_id tda38640_id[] = {
 198         {"tda38640"},
 199         {}
 200 };
 201 MODULE_DEVICE_TABLE(i2c, tda38640_id);
 202
 203 static const struct of_device_id __maybe_unused tda38640_of_match[] = {
 204         { .compatible = "infineon,tda38640"},
 205         { },
 206 };
 207 MODULE_DEVICE_TABLE(of, tda38640_of_match);
 208
 209 /* This is the driver that will be inserted */
 210 static struct i2c_driver tda38640_driver = {
 211         .driver = {
 212                 .name = "tda38640",
 213                 .of_match_table = of_match_ptr(tda38640_of_match),
 214         },
 215         .probe = tda38640_probe,
 216         .id_table = tda38640_id,
 217 };
 218
 219 module_i2c_driver(tda38640_driver);
 220
 221 MODULE_AUTHOR("Patrick Rudolph <[email protected]>");
 222 MODULE_DESCRIPTION("PMBus driver for Infineon TDA38640");
 223 MODULE_LICENSE("GPL");
 224 MODULE_IMPORT_NS("PMBUS");