diff options
Diffstat (limited to 'drivers/mfd/stw481x.c')
| -rw-r--r-- | drivers/mfd/stw481x.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/drivers/mfd/stw481x.c b/drivers/mfd/stw481x.c new file mode 100644 index 000000000..3cc809562 --- /dev/null +++ b/drivers/mfd/stw481x.c @@ -0,0 +1,252 @@ +/* + * 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 */ + static const u8 vcore_val[] = { + 100, 105, 110, 115, 120, 122, 124, 126, 128, + 130, 132, 134, 136, 138, 140, 145 + }; + static const u8 vpll_val[] = { 105, 120, 130, 180 }; + static const 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 = devm_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; +} + +/* + * 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, + .id_table = stw481x_id, +}; + +module_i2c_driver(stw481x_driver); + +MODULE_AUTHOR("Linus Walleij"); +MODULE_DESCRIPTION("STw481x PMIC driver"); +MODULE_LICENSE("GPL v2"); |