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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Core driver for STw4810/STw48114 *5 * Copyright (C) 2013 ST-Ericsson SA6 * Written on behalf of Linaro for ST-Ericsson7 *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 register23 * range 0x00-0x10 dealing with USB is bound to the two special I2C pins used24 * for USB control.25 */26 27/* Registers inside the power control address space */28#define STW_PC_VCORE_SEL 0x05U29#define STW_PC_VAUX_SEL 0x06U30#define STW_PC_VPLL_SEL 0x07U31 32/**33 * stw481x_get_pctl_reg() - get a power control register34 * @stw481x: handle to the stw481x chip35 * @reg: power control register to fetch36 *37 * The power control registers is a set of one-time-programmable registers38 * in its own register space, accessed by writing addess bits to these39 * two registers: bits 7,6,5 of PCTL_REG_LO corresponds to the 3 LSBs of40 * the address and bits 8,9 of PCTL_REG_HI corresponds to the 2 MSBs of41 * the address, forming an address space of 5 bits, i.e. 32 registers42 * 0x00 ... 0x1f can be obtained.43 */44static 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 71static 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, 14577 };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 operation161 * mode, and we always have a GPIO cell.162 */163static struct mfd_cell stw481x_cells[] = {164 {165 .of_compatible = "st,stw481x-vmmc",166 .name = "stw481x-vmmc-regulator",167 .id = -1,168 },169};170 171static const struct regmap_config stw481x_regmap_config = {172 .reg_bits = 8,173 .val_bits = 8,174};175 176static 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 pure221 * device-tree probed driver, but it has to be here due to222 * the structure of the I2C core.223 */224static const struct i2c_device_id stw481x_id[] = {225 { "stw481x" },226 { }227};228MODULE_DEVICE_TABLE(i2c, stw481x_id);229 230static const struct of_device_id stw481x_match[] = {231 { .compatible = "st,stw4810", },232 { .compatible = "st,stw4811", },233 { },234};235MODULE_DEVICE_TABLE(of, stw481x_match);236 237static 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 246module_i2c_driver(stw481x_driver);247 248MODULE_AUTHOR("Linus Walleij");249MODULE_DESCRIPTION("STw481x PMIC driver");250MODULE_LICENSE("GPL v2");251