/* * Core driver for STw4810/STw4811 * * Copyright (C) 2013 ST-Ericsson SA * Written on behalf of Linaro for ST-Ericsson * * Author: Linus Walleij <linus.walleij@linaro.org> * * License terms: GNU General Public License (GPL) version 2 */ #include <linux/err.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/mfd/core.h> #include <linux/mfd/stw481x.h> #include <linux/module.h> #include <linux/regmap.h> #include <linux/spinlock.h> #include <linux/slab.h> /* * This driver can only access the non-USB portions of STw4811, the register * range 0x00-0x10 dealing with USB is bound to the two special I2C pins used * for USB control. */ /* Registers inside the power control address space */ #define STW_PC_VCORE_SEL 0x05U #define STW_PC_VAUX_SEL 0x06U #define STW_PC_VPLL_SEL 0x07U /** * stw481x_get_pctl_reg() - get a power control register * @stw481x: handle to the stw481x chip * @reg: power control register to fetch * * The power control registers is a set of one-time-programmable registers * in its own register space, accessed by writing addess bits to these * two registers: bits 7,6,5 of PCTL_REG_LO corresponds to the 3 LSBs of * the address and bits 8,9 of PCTL_REG_HI corresponds to the 2 MSBs of * the address, forming an address space of 5 bits, i.e. 32 registers * 0x00 ... 0x1f can be obtained. */ static int stw481x_get_pctl_reg(struct stw481x *stw481x, u8 reg) { u8 msb = (reg >> 3) & 0x03; u8 lsb = (reg << 5) & 0xe0; unsigned int val; u8 vrfy; int ret; ret = regmap_write(stw481x->map, STW_PCTL_REG_HI, msb); if (ret) return ret; ret = regmap_write(stw481x->map, STW_PCTL_REG_LO, lsb); if (ret) return ret; ret = regmap_read(stw481x->map, STW_PCTL_REG_HI, &val); if (ret) return ret; vrfy = (val & 0x03) << 3; ret = regmap_read(stw481x->map, STW_PCTL_REG_LO, &val); if (ret) return ret; vrfy |= ((val >> 5) & 0x07); if (vrfy != reg) return -EIO; return (val >> 1) & 0x0f; } static int stw481x_startup(struct stw481x *stw481x) { /* Voltages multiplied by 100 */ u8 vcore_val[] = { 100, 105, 110, 115, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 145 }; u8 vpll_val[] = { 105, 120, 130, 180 }; u8 vaux_val[] = { 15, 18, 25, 28 }; u8 vcore; u8 vcore_slp; u8 vpll; u8 vaux; bool vaux_en; bool it_warn; int ret; unsigned int val; ret = regmap_read(stw481x->map, STW_CONF1, &val); if (ret) return ret; vaux_en = !!(val & STW_CONF1_PDN_VAUX); it_warn = !!(val & STW_CONF1_IT_WARN); dev_info(&stw481x->client->dev, "voltages %s\n", (val & STW_CONF1_V_MONITORING) ? "OK" : "LOW"); dev_info(&stw481x->client->dev, "MMC level shifter %s\n", (val & STW_CONF1_MMC_LS_STATUS) ? "high impedance" : "ON"); dev_info(&stw481x->client->dev, "VMMC: %s\n", (val & STW_CONF1_PDN_VMMC) ? "ON" : "disabled"); dev_info(&stw481x->client->dev, "STw481x power control registers:\n"); ret = stw481x_get_pctl_reg(stw481x, STW_PC_VCORE_SEL); if (ret < 0) return ret; vcore = ret & 0x0f; ret = stw481x_get_pctl_reg(stw481x, STW_PC_VAUX_SEL); if (ret < 0) return ret; vaux = (ret >> 2) & 3; vpll = (ret >> 4) & 1; /* Save bit 4 */ ret = stw481x_get_pctl_reg(stw481x, STW_PC_VPLL_SEL); if (ret < 0) return ret; vpll |= (ret >> 1) & 2; dev_info(&stw481x->client->dev, "VCORE: %u.%uV %s\n", vcore_val[vcore] / 100, vcore_val[vcore] % 100, (ret & 4) ? "ON" : "OFF"); dev_info(&stw481x->client->dev, "VPLL: %u.%uV %s\n", vpll_val[vpll] / 100, vpll_val[vpll] % 100, (ret & 0x10) ? "ON" : "OFF"); dev_info(&stw481x->client->dev, "VAUX: %u.%uV %s\n", vaux_val[vaux] / 10, vaux_val[vaux] % 10, vaux_en ? "ON" : "OFF"); ret = regmap_read(stw481x->map, STW_CONF2, &val); if (ret) return ret; dev_info(&stw481x->client->dev, "TWARN: %s threshold, %s\n", it_warn ? "below" : "above", (val & STW_CONF2_MASK_TWARN) ? "enabled" : "mask through VDDOK"); dev_info(&stw481x->client->dev, "VMMC: %s\n", (val & STW_CONF2_VMMC_EXT) ? "internal" : "external"); dev_info(&stw481x->client->dev, "IT WAKE UP: %s\n", (val & STW_CONF2_MASK_IT_WAKE_UP) ? "enabled" : "masked"); dev_info(&stw481x->client->dev, "GPO1: %s\n", (val & STW_CONF2_GPO1) ? "low" : "high impedance"); dev_info(&stw481x->client->dev, "GPO2: %s\n", (val & STW_CONF2_GPO2) ? "low" : "high impedance"); ret = regmap_read(stw481x->map, STW_VCORE_SLEEP, &val); if (ret) return ret; vcore_slp = val & 0x0f; dev_info(&stw481x->client->dev, "VCORE SLEEP: %u.%uV\n", vcore_val[vcore_slp] / 100, vcore_val[vcore_slp] % 100); return 0; } /* * MFD cells - we have one cell which is selected operation * mode, and we always have a GPIO cell. */ static struct mfd_cell stw481x_cells[] = { { .of_compatible = "st,stw481x-vmmc", .name = "stw481x-vmmc-regulator", .id = -1, }, }; static const struct regmap_config stw481x_regmap_config = { .reg_bits = 8, .val_bits = 8, }; static int stw481x_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct stw481x *stw481x; int ret; int i; stw481x = devm_kzalloc(&client->dev, sizeof(*stw481x), GFP_KERNEL); if (!stw481x) return -ENOMEM; i2c_set_clientdata(client, stw481x); stw481x->client = client; stw481x->map = devm_regmap_init_i2c(client, &stw481x_regmap_config); if (IS_ERR(stw481x->map)) { ret = PTR_ERR(stw481x->map); dev_err(&client->dev, "Failed to allocate register map: %d\n", ret); return ret; } ret = stw481x_startup(stw481x); if (ret) { dev_err(&client->dev, "chip initialization failed\n"); return ret; } /* Set up and register the platform devices. */ for (i = 0; i < ARRAY_SIZE(stw481x_cells); i++) { /* One state holder for all drivers, this is simple */ stw481x_cells[i].platform_data = stw481x; stw481x_cells[i].pdata_size = sizeof(*stw481x); } ret = mfd_add_devices(&client->dev, 0, stw481x_cells, ARRAY_SIZE(stw481x_cells), NULL, 0, NULL); if (ret) return ret; dev_info(&client->dev, "initialized STw481x device\n"); return ret; } static int stw481x_remove(struct i2c_client *client) { mfd_remove_devices(&client->dev); return 0; } /* * This ID table is completely unused, as this is a pure * device-tree probed driver, but it has to be here due to * the structure of the I2C core. */ static const struct i2c_device_id stw481x_id[] = { { "stw481x", 0 }, { }, }; MODULE_DEVICE_TABLE(i2c, stw481x_id); static const struct of_device_id stw481x_match[] = { { .compatible = "st,stw4810", }, { .compatible = "st,stw4811", }, { }, }; MODULE_DEVICE_TABLE(of, stw481x_match); static struct i2c_driver stw481x_driver = { .driver = { .name = "stw481x", .of_match_table = stw481x_match, }, .probe = stw481x_probe, .remove = stw481x_remove, .id_table = stw481x_id, }; module_i2c_driver(stw481x_driver); MODULE_AUTHOR("Linus Walleij"); MODULE_DESCRIPTION("STw481x PMIC driver"); MODULE_LICENSE("GPL v2");