mfd: Introduce retu-mfd driver (c7b76dce) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/mfd/Kconfig

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		@@ -1094,6 +1094,15 @@ config MFD_VIPERBOARD
		You need to select the mfd cell drivers separately.
		The drivers do not support all features the board exposes.

		config MFD_RETU
		tristate "Support for Retu multi-function device"
		select MFD_CORE
		depends on I2C
		select REGMAP_IRQ
		help
		Retu is a multi-function device found on Nokia Internet Tablets
		(770, N800 and N810).

		endmenu
		endif

drivers/mfd/Makefile

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		@@ -145,3 +145,4 @@ obj-$(CONFIG_MFD_RC5T583) += rc5t583.o rc5t583-irq.o
		obj-$(CONFIG_MFD_SEC_CORE) += sec-core.o sec-irq.o
		obj-$(CONFIG_MFD_SYSCON) += syscon.o
		obj-$(CONFIG_MFD_LM3533) += lm3533-core.o lm3533-ctrlbank.o
		obj-$(CONFIG_MFD_RETU) += retu-mfd.o

drivers/mfd/retu-mfd.c

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		/*
		* Retu MFD driver
		*
		* Copyright (C) 2004, 2005 Nokia Corporation
		*
		* Based on code written by Juha Yrjölä, David Weinehall and Mikko Ylinen.
		* Rewritten by Aaro Koskinen.
		*
		* This file is subject to the terms and conditions of the GNU General
		* Public License. See the file "COPYING" in the main directory of this
		* archive for more details.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*/

		#include <linux/err.h>
		#include <linux/i2c.h>
		#include <linux/irq.h>
		#include <linux/init.h>
		#include <linux/slab.h>
		#include <linux/mutex.h>
		#include <linux/module.h>
		#include <linux/regmap.h>
		#include <linux/mfd/core.h>
		#include <linux/mfd/retu.h>
		#include <linux/interrupt.h>
		#include <linux/moduleparam.h>

		/* Registers */
		#define RETU_REG_ASICR 0x00 /* ASIC ID and revision */
		#define RETU_REG_ASICR_VILMA (1 << 7) /* Bit indicating Vilma */
		#define RETU_REG_IDR 0x01 /* Interrupt ID */
		#define RETU_REG_IMR 0x02 /* Interrupt mask */

		/* Interrupt sources */
		#define RETU_INT_PWR 0 /* Power button */

		struct retu_dev {
		struct regmap *regmap;
		struct device *dev;
		struct mutex mutex;
		struct regmap_irq_chip_data *irq_data;
		};

		static struct resource retu_pwrbutton_res[] = {
		{
		.name = "retu-pwrbutton",
		.start = RETU_INT_PWR,
		.end = RETU_INT_PWR,
		.flags = IORESOURCE_IRQ,
		},
		};

		static struct mfd_cell retu_devs[] = {
		{
		.name = "retu-wdt"
		},
		{
		.name = "retu-pwrbutton",
		.resources = retu_pwrbutton_res,
		.num_resources = ARRAY_SIZE(retu_pwrbutton_res),
		}
		};

		static struct regmap_irq retu_irqs[] = {
		[RETU_INT_PWR] = {
		.mask = 1 << RETU_INT_PWR,
		}
		};

		static struct regmap_irq_chip retu_irq_chip = {
		.name = "RETU",
		.irqs = retu_irqs,
		.num_irqs = ARRAY_SIZE(retu_irqs),
		.num_regs = 1,
		.status_base = RETU_REG_IDR,
		.mask_base = RETU_REG_IMR,
		.ack_base = RETU_REG_IDR,
		};

		/* Retu device registered for the power off. */
		static struct retu_dev *retu_pm_power_off;

		int retu_read(struct retu_dev *rdev, u8 reg)
		{
		int ret;
		int value;

		mutex_lock(&rdev->mutex);
		ret = regmap_read(rdev->regmap, reg, &value);
		mutex_unlock(&rdev->mutex);

		return ret ? ret : value;
		}
		EXPORT_SYMBOL_GPL(retu_read);

		int retu_write(struct retu_dev *rdev, u8 reg, u16 data)
		{
		int ret;

		mutex_lock(&rdev->mutex);
		ret = regmap_write(rdev->regmap, reg, data);
		mutex_unlock(&rdev->mutex);

		return ret;
		}
		EXPORT_SYMBOL_GPL(retu_write);

		static void retu_power_off(void)
		{
		struct retu_dev *rdev = retu_pm_power_off;
		int reg;

		mutex_lock(&retu_pm_power_off->mutex);

		/* Ignore power button state */
		regmap_read(rdev->regmap, RETU_REG_CC1, &reg);
		regmap_write(rdev->regmap, RETU_REG_CC1, reg \| 2);

		/* Expire watchdog immediately */
		regmap_write(rdev->regmap, RETU_REG_WATCHDOG, 0);

		/* Wait for poweroff */
		for (;;)
		cpu_relax();

		mutex_unlock(&retu_pm_power_off->mutex);
		}

		static int retu_regmap_read(void context, const void reg, size_t reg_size,
		void *val, size_t val_size)
		{
		int ret;
		struct device *dev = context;
		struct i2c_client *i2c = to_i2c_client(dev);

		BUG_ON(reg_size != 1 \|\| val_size != 2);

		ret = i2c_smbus_read_word_data(i2c, (u8 const )reg);
		if (ret < 0)
		return ret;

		(u16 )val = ret;
		return 0;
		}

		static int retu_regmap_write(void context, const void data, size_t count)
		{
		u8 reg;
		u16 val;
		struct device *dev = context;
		struct i2c_client *i2c = to_i2c_client(dev);

		BUG_ON(count != sizeof(reg) + sizeof(val));
		memcpy(&reg, data, sizeof(reg));
		memcpy(&val, data + sizeof(reg), sizeof(val));
		return i2c_smbus_write_word_data(i2c, reg, val);
		}

		static struct regmap_bus retu_bus = {
		.read = retu_regmap_read,
		.write = retu_regmap_write,
		.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
		};

		static struct regmap_config retu_config = {
		.reg_bits = 8,
		.val_bits = 16,
		};

		static int __devinit retu_probe(struct i2c_client *i2c,
		const struct i2c_device_id *id)
		{
		struct retu_dev *rdev;
		int ret;

		rdev = devm_kzalloc(&i2c->dev, sizeof(*rdev), GFP_KERNEL);
		if (rdev == NULL)
		return -ENOMEM;

		i2c_set_clientdata(i2c, rdev);
		rdev->dev = &i2c->dev;
		mutex_init(&rdev->mutex);
		rdev->regmap = devm_regmap_init(&i2c->dev, &retu_bus, &i2c->dev,
		&retu_config);
		if (IS_ERR(rdev->regmap))
		return PTR_ERR(rdev->regmap);

		ret = retu_read(rdev, RETU_REG_ASICR);
		if (ret < 0) {
		dev_err(rdev->dev, "could not read Retu revision: %d\n", ret);
		return ret;
		}

		dev_info(rdev->dev, "Retu%s v%d.%d found\n",
		(ret & RETU_REG_ASICR_VILMA) ? " & Vilma" : "",
		(ret >> 4) & 0x7, ret & 0xf);

		/* Mask all RETU interrupts. */
		ret = retu_write(rdev, RETU_REG_IMR, 0xffff);
		if (ret < 0)
		return ret;

		ret = regmap_add_irq_chip(rdev->regmap, i2c->irq, IRQF_ONESHOT, -1,
		&retu_irq_chip, &rdev->irq_data);
		if (ret < 0)
		return ret;

		ret = mfd_add_devices(rdev->dev, -1, retu_devs, ARRAY_SIZE(retu_devs),
		NULL, regmap_irq_chip_get_base(rdev->irq_data),
		NULL);
		if (ret < 0) {
		regmap_del_irq_chip(i2c->irq, rdev->irq_data);
		return ret;
		}

		if (!pm_power_off) {
		retu_pm_power_off = rdev;
		pm_power_off = retu_power_off;
		}

		return 0;
		}

		static int __devexit retu_remove(struct i2c_client *i2c)
		{
		struct retu_dev *rdev = i2c_get_clientdata(i2c);

		if (retu_pm_power_off == rdev) {
		pm_power_off = NULL;
		retu_pm_power_off = NULL;
		}
		mfd_remove_devices(rdev->dev);
		regmap_del_irq_chip(i2c->irq, rdev->irq_data);

		return 0;
		}

		static const struct i2c_device_id retu_id[] = {
		{ "retu-mfd", 0 },
		{ }
		};
		MODULE_DEVICE_TABLE(i2c, retu_id);

		static struct i2c_driver retu_driver = {
		.driver = {
		.name = "retu-mfd",
		.owner = THIS_MODULE,
		},
		.probe = retu_probe,
		.remove = retu_remove,
		.id_table = retu_id,
		};
		module_i2c_driver(retu_driver);

		MODULE_DESCRIPTION("Retu MFD driver");
		MODULE_AUTHOR("Juha Yrjölä");
		MODULE_AUTHOR("David Weinehall");
		MODULE_AUTHOR("Mikko Ylinen");
		MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
		MODULE_LICENSE("GPL");

include/linux/mfd/retu.h

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		/*
		* Retu MFD driver interface
		*
		* This file is subject to the terms and conditions of the GNU General
		* Public License. See the file "COPYING" in the main directory of this
		* archive for more details.
		*/

		#ifndef __LINUX_MFD_RETU_H
		#define __LINUX_MFD_RETU_H

		struct retu_dev;

		int retu_read(struct retu_dev *, u8);
		int retu_write(struct retu_dev *, u8, u16);

		/* Registers */
		#define RETU_REG_WATCHDOG 0x17 /* Watchdog */
		#define RETU_REG_CC1 0x0d /* Common control register 1 */
		#define RETU_REG_STATUS 0x16 /* Status register */

		#endif /* __LINUX_MFD_RETU_H */