1 /* 2 * Core driver for STw4810/STw4811 3 * 4 * Copyright (C) 2013 ST-Ericsson SA 5 * Written on behalf of Linaro for ST-Ericsson 6 * 7 * Author: Linus Walleij <linus.walleij@linaro.org> 8 * 9 * License terms: GNU General Public License (GPL) version 2 10 */ 11 12 #include <linux/err.h> 13 #include <linux/i2c.h> 14 #include <linux/init.h> 15 #include <linux/mfd/core.h> 16 #include <linux/mfd/stw481x.h> 17 #include <linux/module.h> 18 #include <linux/regmap.h> 19 #include <linux/spinlock.h> 20 #include <linux/slab.h> 21 22 /* 23 * This driver can only access the non-USB portions of STw4811, the register 24 * range 0x00-0x10 dealing with USB is bound to the two special I2C pins used 25 * for USB control. 26 */ 27 28 /* Registers inside the power control address space */ 29 #define STW_PC_VCORE_SEL 0x05U 30 #define STW_PC_VAUX_SEL 0x06U 31 #define STW_PC_VPLL_SEL 0x07U 32 33 /** 34 * stw481x_get_pctl_reg() - get a power control register 35 * @stw481x: handle to the stw481x chip 36 * @reg: power control register to fetch 37 * 38 * The power control registers is a set of one-time-programmable registers 39 * in its own register space, accessed by writing addess bits to these 40 * two registers: bits 7,6,5 of PCTL_REG_LO corresponds to the 3 LSBs of 41 * the address and bits 8,9 of PCTL_REG_HI corresponds to the 2 MSBs of 42 * the address, forming an address space of 5 bits, i.e. 32 registers 43 * 0x00 ... 0x1f can be obtained. 44 */ 45 static int stw481x_get_pctl_reg(struct stw481x *stw481x, u8 reg) 46 { 47 u8 msb = (reg >> 3) & 0x03; 48 u8 lsb = (reg << 5) & 0xe0; 49 unsigned int val; 50 u8 vrfy; 51 int ret; 52 53 ret = regmap_write(stw481x->map, STW_PCTL_REG_HI, msb); 54 if (ret) 55 return ret; 56 ret = regmap_write(stw481x->map, STW_PCTL_REG_LO, lsb); 57 if (ret) 58 return ret; 59 ret = regmap_read(stw481x->map, STW_PCTL_REG_HI, &val); 60 if (ret) 61 return ret; 62 vrfy = (val & 0x03) << 3; 63 ret = regmap_read(stw481x->map, STW_PCTL_REG_LO, &val); 64 if (ret) 65 return ret; 66 vrfy |= ((val >> 5) & 0x07); 67 if (vrfy != reg) 68 return -EIO; 69 return (val >> 1) & 0x0f; 70 } 71 72 static int stw481x_startup(struct stw481x *stw481x) 73 { 74 /* Voltages multiplied by 100 */ 75 static const u8 vcore_val[] = { 76 100, 105, 110, 115, 120, 122, 124, 126, 128, 77 130, 132, 134, 136, 138, 140, 145 78 }; 79 static const u8 vpll_val[] = { 105, 120, 130, 180 }; 80 static const u8 vaux_val[] = { 15, 18, 25, 28 }; 81 u8 vcore; 82 u8 vcore_slp; 83 u8 vpll; 84 u8 vaux; 85 bool vaux_en; 86 bool it_warn; 87 int ret; 88 unsigned int val; 89 90 ret = regmap_read(stw481x->map, STW_CONF1, &val); 91 if (ret) 92 return ret; 93 vaux_en = !!(val & STW_CONF1_PDN_VAUX); 94 it_warn = !!(val & STW_CONF1_IT_WARN); 95 96 dev_info(&stw481x->client->dev, "voltages %s\n", 97 (val & STW_CONF1_V_MONITORING) ? "OK" : "LOW"); 98 dev_info(&stw481x->client->dev, "MMC level shifter %s\n", 99 (val & STW_CONF1_MMC_LS_STATUS) ? "high impedance" : "ON"); 100 dev_info(&stw481x->client->dev, "VMMC: %s\n", 101 (val & STW_CONF1_PDN_VMMC) ? "ON" : "disabled"); 102 103 dev_info(&stw481x->client->dev, "STw481x power control registers:\n"); 104 105 ret = stw481x_get_pctl_reg(stw481x, STW_PC_VCORE_SEL); 106 if (ret < 0) 107 return ret; 108 vcore = ret & 0x0f; 109 110 ret = stw481x_get_pctl_reg(stw481x, STW_PC_VAUX_SEL); 111 if (ret < 0) 112 return ret; 113 vaux = (ret >> 2) & 3; 114 vpll = (ret >> 4) & 1; /* Save bit 4 */ 115 116 ret = stw481x_get_pctl_reg(stw481x, STW_PC_VPLL_SEL); 117 if (ret < 0) 118 return ret; 119 vpll |= (ret >> 1) & 2; 120 121 dev_info(&stw481x->client->dev, "VCORE: %u.%uV %s\n", 122 vcore_val[vcore] / 100, vcore_val[vcore] % 100, 123 (ret & 4) ? "ON" : "OFF"); 124 125 dev_info(&stw481x->client->dev, "VPLL: %u.%uV %s\n", 126 vpll_val[vpll] / 100, vpll_val[vpll] % 100, 127 (ret & 0x10) ? "ON" : "OFF"); 128 129 dev_info(&stw481x->client->dev, "VAUX: %u.%uV %s\n", 130 vaux_val[vaux] / 10, vaux_val[vaux] % 10, 131 vaux_en ? "ON" : "OFF"); 132 133 ret = regmap_read(stw481x->map, STW_CONF2, &val); 134 if (ret) 135 return ret; 136 137 dev_info(&stw481x->client->dev, "TWARN: %s threshold, %s\n", 138 it_warn ? "below" : "above", 139 (val & STW_CONF2_MASK_TWARN) ? 140 "enabled" : "mask through VDDOK"); 141 dev_info(&stw481x->client->dev, "VMMC: %s\n", 142 (val & STW_CONF2_VMMC_EXT) ? "internal" : "external"); 143 dev_info(&stw481x->client->dev, "IT WAKE UP: %s\n", 144 (val & STW_CONF2_MASK_IT_WAKE_UP) ? "enabled" : "masked"); 145 dev_info(&stw481x->client->dev, "GPO1: %s\n", 146 (val & STW_CONF2_GPO1) ? "low" : "high impedance"); 147 dev_info(&stw481x->client->dev, "GPO2: %s\n", 148 (val & STW_CONF2_GPO2) ? "low" : "high impedance"); 149 150 ret = regmap_read(stw481x->map, STW_VCORE_SLEEP, &val); 151 if (ret) 152 return ret; 153 vcore_slp = val & 0x0f; 154 dev_info(&stw481x->client->dev, "VCORE SLEEP: %u.%uV\n", 155 vcore_val[vcore_slp] / 100, vcore_val[vcore_slp] % 100); 156 157 return 0; 158 } 159 160 /* 161 * MFD cells - we have one cell which is selected operation 162 * mode, and we always have a GPIO cell. 163 */ 164 static struct mfd_cell stw481x_cells[] = { 165 { 166 .of_compatible = "st,stw481x-vmmc", 167 .name = "stw481x-vmmc-regulator", 168 .id = -1, 169 }, 170 }; 171 172 static const struct regmap_config stw481x_regmap_config = { 173 .reg_bits = 8, 174 .val_bits = 8, 175 }; 176 177 static int stw481x_probe(struct i2c_client *client, 178 const struct i2c_device_id *id) 179 { 180 struct stw481x *stw481x; 181 int ret; 182 int i; 183 184 stw481x = devm_kzalloc(&client->dev, sizeof(*stw481x), GFP_KERNEL); 185 if (!stw481x) 186 return -ENOMEM; 187 188 i2c_set_clientdata(client, stw481x); 189 stw481x->client = client; 190 stw481x->map = devm_regmap_init_i2c(client, &stw481x_regmap_config); 191 if (IS_ERR(stw481x->map)) { 192 ret = PTR_ERR(stw481x->map); 193 dev_err(&client->dev, "Failed to allocate register map: %d\n", 194 ret); 195 return ret; 196 } 197 198 ret = stw481x_startup(stw481x); 199 if (ret) { 200 dev_err(&client->dev, "chip initialization failed\n"); 201 return ret; 202 } 203 204 /* Set up and register the platform devices. */ 205 for (i = 0; i < ARRAY_SIZE(stw481x_cells); i++) { 206 /* One state holder for all drivers, this is simple */ 207 stw481x_cells[i].platform_data = stw481x; 208 stw481x_cells[i].pdata_size = sizeof(*stw481x); 209 } 210 211 ret = devm_mfd_add_devices(&client->dev, 0, stw481x_cells, 212 ARRAY_SIZE(stw481x_cells), NULL, 0, NULL); 213 if (ret) 214 return ret; 215 216 dev_info(&client->dev, "initialized STw481x device\n"); 217 218 return ret; 219 } 220 221 /* 222 * This ID table is completely unused, as this is a pure 223 * device-tree probed driver, but it has to be here due to 224 * the structure of the I2C core. 225 */ 226 static const struct i2c_device_id stw481x_id[] = { 227 { "stw481x", 0 }, 228 { }, 229 }; 230 MODULE_DEVICE_TABLE(i2c, stw481x_id); 231 232 static const struct of_device_id stw481x_match[] = { 233 { .compatible = "st,stw4810", }, 234 { .compatible = "st,stw4811", }, 235 { }, 236 }; 237 MODULE_DEVICE_TABLE(of, stw481x_match); 238 239 static struct i2c_driver stw481x_driver = { 240 .driver = { 241 .name = "stw481x", 242 .of_match_table = stw481x_match, 243 }, 244 .probe = stw481x_probe, 245 .id_table = stw481x_id, 246 }; 247 248 module_i2c_driver(stw481x_driver); 249 250 MODULE_AUTHOR("Linus Walleij"); 251 MODULE_DESCRIPTION("STw481x PMIC driver"); 252 MODULE_LICENSE("GPL v2"); 253