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 { 178 struct stw481x *stw481x; 179 int ret; 180 int i; 181 182 stw481x = devm_kzalloc(&client->dev, sizeof(*stw481x), GFP_KERNEL); 183 if (!stw481x) 184 return -ENOMEM; 185 186 i2c_set_clientdata(client, stw481x); 187 stw481x->client = client; 188 stw481x->map = devm_regmap_init_i2c(client, &stw481x_regmap_config); 189 if (IS_ERR(stw481x->map)) { 190 ret = PTR_ERR(stw481x->map); 191 dev_err(&client->dev, "Failed to allocate register map: %d\n", 192 ret); 193 return ret; 194 } 195 196 ret = stw481x_startup(stw481x); 197 if (ret) { 198 dev_err(&client->dev, "chip initialization failed\n"); 199 return ret; 200 } 201 202 /* Set up and register the platform devices. */ 203 for (i = 0; i < ARRAY_SIZE(stw481x_cells); i++) { 204 /* One state holder for all drivers, this is simple */ 205 stw481x_cells[i].platform_data = stw481x; 206 stw481x_cells[i].pdata_size = sizeof(*stw481x); 207 } 208 209 ret = devm_mfd_add_devices(&client->dev, 0, stw481x_cells, 210 ARRAY_SIZE(stw481x_cells), NULL, 0, NULL); 211 if (ret) 212 return ret; 213 214 dev_info(&client->dev, "initialized STw481x device\n"); 215 216 return ret; 217 } 218 219 /* 220 * This ID table is completely unused, as this is a pure 221 * device-tree probed driver, but it has to be here due to 222 * the structure of the I2C core. 223 */ 224 static const struct i2c_device_id stw481x_id[] = { 225 { "stw481x" }, 226 { } 227 }; 228 MODULE_DEVICE_TABLE(i2c, stw481x_id); 229 230 static const struct of_device_id stw481x_match[] = { 231 { .compatible = "st,stw4810", }, 232 { .compatible = "st,stw4811", }, 233 { }, 234 }; 235 MODULE_DEVICE_TABLE(of, stw481x_match); 236 237 static struct i2c_driver stw481x_driver = { 238 .driver = { 239 .name = "stw481x", 240 .of_match_table = stw481x_match, 241 }, 242 .probe = stw481x_probe, 243 .id_table = stw481x_id, 244 }; 245 246 module_i2c_driver(stw481x_driver); 247 248 MODULE_AUTHOR("Linus Walleij"); 249 MODULE_DESCRIPTION("STw481x PMIC driver"); 250 MODULE_LICENSE("GPL v2"); 251