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Commit 60013b94 authored by Linus Walleij's avatar Linus Walleij Committed by Lee Jones
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mfd: Add STw481x driver 



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: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent ca13ce37

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

drivers/mfd/Makefile

+1 −0
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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

drivers/mfd/stw481x.c

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/*

 * 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");

include/linux/mfd/stw481x.h

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/*

 * 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