drivers/mfd/stw481x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Core driver for STw4810/STw4811
   4  *
   5  * Copyright (C) 2013 ST-Ericsson SA
   6  * Written on behalf of Linaro for ST-Ericsson
   7  *
   8  * Author: Linus Walleij <linus.walleij@linaro.org>
   9  */
  10
  11 #include <linux/err.h>
  12 #include <linux/i2c.h>
  13 #include <linux/init.h>
  14 #include <linux/mfd/core.h>
  15 #include <linux/mfd/stw481x.h>
  16 #include <linux/module.h>
  17 #include <linux/regmap.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/slab.h>
  20
  21 /*
  22  * This driver can only access the non-USB portions of STw4811, the register
  23  * range 0x00-0x10 dealing with USB is bound to the two special I2C pins used
  24  * for USB control.
  25  */
  26
  27 /* Registers inside the power control address space */
  28 #define STW_PC_VCORE_SEL        0x05U
  29 #define STW_PC_VAUX_SEL         0x06U
  30 #define STW_PC_VPLL_SEL         0x07U
  31
  32 /**
  33  * stw481x_get_pctl_reg() - get a power control register
  34  * @stw481x: handle to the stw481x chip
  35  * @reg: power control register to fetch
  36  *
  37  * The power control registers is a set of one-time-programmable registers
  38  * in its own register space, accessed by writing addess bits to these
  39  * two registers: bits 7,6,5 of PCTL_REG_LO corresponds to the 3 LSBs of
  40  * the address and bits 8,9 of PCTL_REG_HI corresponds to the 2 MSBs of
  41  * the address, forming an address space of 5 bits, i.e. 32 registers
  42  * 0x00 ... 0x1f can be obtained.
  43  */
  44 static int stw481x_get_pctl_reg(struct stw481x *stw481x, u8 reg)
  45 {
  46         u8 msb = (reg >> 3) & 0x03;
  47         u8 lsb = (reg << 5) & 0xe0;
  48         unsigned int val;
  49         u8 vrfy;
  50         int ret;
  51
  52         ret = regmap_write(stw481x->map, STW_PCTL_REG_HI, msb);
  53         if (ret)
  54                 return ret;
  55         ret = regmap_write(stw481x->map, STW_PCTL_REG_LO, lsb);
  56         if (ret)
  57                 return ret;
  58         ret = regmap_read(stw481x->map, STW_PCTL_REG_HI, &val);
  59         if (ret)
  60                 return ret;
  61         vrfy = (val & 0x03) << 3;
  62         ret = regmap_read(stw481x->map, STW_PCTL_REG_LO, &val);
  63         if (ret)
  64                 return ret;
  65         vrfy |= ((val >> 5) & 0x07);
  66         if (vrfy != reg)
  67                 return -EIO;
  68         return (val >> 1) & 0x0f;
  69 }
  70
  71 static int stw481x_startup(struct stw481x *stw481x)
  72 {
  73         /* Voltages multiplied by 100 */
  74         static const u8 vcore_val[] = {
  75                 100, 105, 110, 115, 120, 122, 124, 126, 128,
  76                 130, 132, 134, 136, 138, 140, 145
  77         };
  78         static const u8 vpll_val[] = { 105, 120, 130, 180 };
  79         static const u8 vaux_val[] = { 15, 18, 25, 28 };
  80         u8 vcore;
  81         u8 vcore_slp;
  82         u8 vpll;
  83         u8 vaux;
  84         bool vaux_en;
  85         bool it_warn;
  86         int ret;
  87         unsigned int val;
  88
  89         ret = regmap_read(stw481x->map, STW_CONF1, &val);
  90         if (ret)
  91                 return ret;
  92         vaux_en = !!(val & STW_CONF1_PDN_VAUX);
  93         it_warn = !!(val & STW_CONF1_IT_WARN);
  94
  95         dev_info(&stw481x->client->dev, "voltages %s\n",
  96                 (val & STW_CONF1_V_MONITORING) ? "OK" : "LOW");
  97         dev_info(&stw481x->client->dev, "MMC level shifter %s\n",
  98                 (val & STW_CONF1_MMC_LS_STATUS) ? "high impedance" : "ON");
  99         dev_info(&stw481x->client->dev, "VMMC: %s\n",
 100                 (val & STW_CONF1_PDN_VMMC) ? "ON" : "disabled");
 101
 102         dev_info(&stw481x->client->dev, "STw481x power control registers:\n");
 103
 104         ret = stw481x_get_pctl_reg(stw481x, STW_PC_VCORE_SEL);
 105         if (ret < 0)
 106                 return ret;
 107         vcore = ret & 0x0f;
 108
 109         ret = stw481x_get_pctl_reg(stw481x, STW_PC_VAUX_SEL);
 110         if (ret < 0)
 111                 return ret;
 112         vaux = (ret >> 2) & 3;
 113         vpll = (ret >> 4) & 1; /* Save bit 4 */
 114
 115         ret = stw481x_get_pctl_reg(stw481x, STW_PC_VPLL_SEL);
 116         if (ret < 0)
 117                 return ret;
 118         vpll |= (ret >> 1) & 2;
 119
 120         dev_info(&stw481x->client->dev, "VCORE: %u.%uV %s\n",
 121                 vcore_val[vcore] / 100, vcore_val[vcore] % 100,
 122                 (ret & 4) ? "ON" : "OFF");
 123
 124         dev_info(&stw481x->client->dev, "VPLL:  %u.%uV %s\n",
 125                 vpll_val[vpll] / 100, vpll_val[vpll] % 100,
 126                 (ret & 0x10) ? "ON" : "OFF");
 127
 128         dev_info(&stw481x->client->dev, "VAUX:  %u.%uV %s\n",
 129                 vaux_val[vaux] / 10, vaux_val[vaux] % 10,
 130                 vaux_en ? "ON" : "OFF");
 131
 132         ret = regmap_read(stw481x->map, STW_CONF2, &val);
 133         if (ret)
 134                 return ret;
 135
 136         dev_info(&stw481x->client->dev, "TWARN: %s threshold, %s\n",
 137                 it_warn ? "below" : "above",
 138                 (val & STW_CONF2_MASK_TWARN) ?
 139                  "enabled" : "mask through VDDOK");
 140         dev_info(&stw481x->client->dev, "VMMC: %s\n",
 141                 (val & STW_CONF2_VMMC_EXT) ? "internal" : "external");
 142         dev_info(&stw481x->client->dev, "IT WAKE UP: %s\n",
 143                 (val & STW_CONF2_MASK_IT_WAKE_UP) ? "enabled" : "masked");
 144         dev_info(&stw481x->client->dev, "GPO1: %s\n",
 145                 (val & STW_CONF2_GPO1) ? "low" : "high impedance");
 146         dev_info(&stw481x->client->dev, "GPO2: %s\n",
 147                 (val & STW_CONF2_GPO2) ? "low" : "high impedance");
 148
 149         ret = regmap_read(stw481x->map, STW_VCORE_SLEEP, &val);
 150         if (ret)
 151                 return ret;
 152         vcore_slp = val & 0x0f;
 153         dev_info(&stw481x->client->dev, "VCORE SLEEP: %u.%uV\n",
 154                 vcore_val[vcore_slp] / 100, vcore_val[vcore_slp] % 100);
 155
 156         return 0;
 157 }
 158
 159 /*
 160  * MFD cells - we have one cell which is selected operation
 161  * mode, and we always have a GPIO cell.
 162  */
 163 static struct mfd_cell stw481x_cells[] = {
 164         {
 165                 .of_compatible = "st,stw481x-vmmc",
 166                 .name = "stw481x-vmmc-regulator",
 167                 .id = -1,
 168         },
 169 };
 170
 171 static const struct regmap_config stw481x_regmap_config = {
 172         .reg_bits = 8,
 173         .val_bits = 8,
 174 };
 175
 176 static int stw481x_probe(struct i2c_client *client,
 177                          const struct i2c_device_id *id)
 178 {
 179         struct stw481x                  *stw481x;
 180         int ret;
 181         int i;
 182
 183         stw481x = devm_kzalloc(&client->dev, sizeof(*stw481x), GFP_KERNEL);
 184         if (!stw481x)
 185                 return -ENOMEM;
 186
 187         i2c_set_clientdata(client, stw481x);
 188         stw481x->client = client;
 189         stw481x->map = devm_regmap_init_i2c(client, &stw481x_regmap_config);
 190         if (IS_ERR(stw481x->map)) {
 191                 ret = PTR_ERR(stw481x->map);
 192                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 193                         ret);
 194                 return ret;
 195         }
 196
 197         ret = stw481x_startup(stw481x);
 198         if (ret) {
 199                 dev_err(&client->dev, "chip initialization failed\n");
 200                 return ret;
 201         }
 202
 203         /* Set up and register the platform devices. */
 204         for (i = 0; i < ARRAY_SIZE(stw481x_cells); i++) {
 205                 /* One state holder for all drivers, this is simple */
 206                 stw481x_cells[i].platform_data = stw481x;
 207                 stw481x_cells[i].pdata_size = sizeof(*stw481x);
 208         }
 209
 210         ret = devm_mfd_add_devices(&client->dev, 0, stw481x_cells,
 211                                    ARRAY_SIZE(stw481x_cells), NULL, 0, NULL);
 212         if (ret)
 213                 return ret;
 214
 215         dev_info(&client->dev, "initialized STw481x device\n");
 216
 217         return ret;
 218 }
 219
 220 /*
 221  * This ID table is completely unused, as this is a pure
 222  * device-tree probed driver, but it has to be here due to
 223  * the structure of the I2C core.
 224  */
 225 static const struct i2c_device_id stw481x_id[] = {
 226         { "stw481x", 0 },
 227         { },
 228 };
 229 MODULE_DEVICE_TABLE(i2c, stw481x_id);
 230
 231 static const struct of_device_id stw481x_match[] = {
 232         { .compatible = "st,stw4810", },
 233         { .compatible = "st,stw4811", },
 234         { },
 235 };
 236 MODULE_DEVICE_TABLE(of, stw481x_match);
 237
 238 static struct i2c_driver stw481x_driver = {
 239         .driver = {
 240                 .name   = "stw481x",
 241                 .of_match_table = stw481x_match,
 242         },
 243         .probe          = stw481x_probe,
 244         .id_table       = stw481x_id,
 245 };
 246
 247 module_i2c_driver(stw481x_driver);
 248
 249 MODULE_AUTHOR("Linus Walleij");
 250 MODULE_DESCRIPTION("STw481x PMIC driver");
 251 MODULE_LICENSE("GPL v2");