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mfd: Add STw481x driver

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This adds a driver for the STw481x PMICs found in the Nomadik
family of platforms. This one uses pure device tree probing.
Print some of the OTP registers on boot and register a regulator
MFD child.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Linus Walleij 2013-09-22 21:49:18 +02:00 committed by Lee Jones
parent ca13ce3701
commit 60013b94d9
4 changed files with 317 additions and 0 deletions
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10
drivers/mfd/Kconfig
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@ -1151,6 +1151,16 @@ config MFD_WM8994
core support for the WM8994, in order to use the actual
functionaltiy of the device other drivers must be enabled.
config MFD_STW481X
bool "Support for ST Microelectronics STw481x"
depends on I2C && ARCH_NOMADIK
select REGMAP_I2C
select MFD_CORE
help
Select this option to enable the STw481x chip driver used
in various ST Microelectronics and ST-Ericsson embedded
Nomadik series.
endmenu
endif

1
drivers/mfd/Makefile
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@ -162,3 +162,4 @@ obj-$(CONFIG_MFD_LM3533) += lm3533-core.o lm3533-ctrlbank.o
obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o vexpress-sysreg.o
obj-$(CONFIG_MFD_RETU) += retu-mfd.o
obj-$(CONFIG_MFD_AS3711) += as3711.o
obj-$(CONFIG_MFD_STW481X) += stw481x.o

250
drivers/mfd/stw481x.c Normal file
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@ -0,0 +1,250 @@
/*
* 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,
},
};
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);
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 },
{ },
};
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");

56
include/linux/mfd/stw481x.h Normal file
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@ -0,0 +1,56 @@
/*
* Copyright (C) 2011 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
*/
#ifndef MFD_STW481X_H
#define MFD_STW481X_H
#include <linux/i2c.h>
#include <linux/regulator/machine.h>
#include <linux/regmap.h>
#include <linux/bitops.h>
/* These registers are accessed from more than one driver */
#define STW_CONF1 0x11U
#define STW_CONF1_PDN_VMMC 0x01U
#define STW_CONF1_VMMC_MASK 0x0eU
#define STW_CONF1_VMMC_1_8V 0x02U
#define STW_CONF1_VMMC_2_85V 0x04U
#define STW_CONF1_VMMC_3V 0x06U
#define STW_CONF1_VMMC_1_85V 0x08U
#define STW_CONF1_VMMC_2_6V 0x0aU
#define STW_CONF1_VMMC_2_7V 0x0cU
#define STW_CONF1_VMMC_3_3V 0x0eU
#define STW_CONF1_MMC_LS_STATUS 0x10U
#define STW_PCTL_REG_LO 0x1eU
#define STW_PCTL_REG_HI 0x1fU
#define STW_CONF1_V_MONITORING 0x20U
#define STW_CONF1_IT_WARN 0x40U
#define STW_CONF1_PDN_VAUX 0x80U
#define STW_CONF2 0x20U
#define STW_CONF2_MASK_TWARN 0x01U
#define STW_CONF2_VMMC_EXT 0x02U
#define STW_CONF2_MASK_IT_WAKE_UP 0x04U
#define STW_CONF2_GPO1 0x08U
#define STW_CONF2_GPO2 0x10U
#define STW_VCORE_SLEEP 0x21U
/**
* struct stw481x - state holder for the Stw481x drivers
* @mutex: mutex to serialize I2C accesses
* @i2c_client: corresponding I2C client
* @regulator: regulator device for regulator children
* @map: regmap handle to access device registers
*/
struct stw481x {
struct mutex lock;
struct i2c_client *client;
struct regulator_dev *vmmc_regulator;
struct regmap *map;
};
#endif