Date: Tue, 20 Nov 2012 10:34:27 -0800
From: Tony Lindgren <tony@atomide.com>
To: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org,
        sameo@linux.intel.com
Subject: Re: [RESEND PATCH v3 2/4] mfd: introduce retu-mfd driver
Message-ID: <20121120183427.GK18567@atomide.com>
References: <1352747326-2195-1-git-send-email-aaro.koskinen@iki.fi>
 <1352747326-2195-3-git-send-email-aaro.koskinen@iki.fi>
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* Aaro Koskinen <aaro.koskinen@iki.fi> [121112 11:11]:
> Retu is a multi-function device found on Nokia Internet Tablets
> implementing at least watchdog, RTC, headset detection and power button
> functionality.
> 
> This patch implements minimum functionality providing register access,
> IRQ handling and power off functions.

Samuel, you can pick this one up separately now that Wolfram has taken
the i2c-cbus driver.

Also, just noticed that this probably should depend on I2C_CBUS as this
chip will not communicate over other I2C adapters?

Regards,

Tony
 
> Cc: sameo@linux.intel.com
> Acked-by: Felipe Balbi <balbi@ti.com>
> Acked-by: Tony Lindgren <tony@atomide.com>
> Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
> ---
>  drivers/mfd/Kconfig      |    9 ++
>  drivers/mfd/Makefile     |    1 +
>  drivers/mfd/retu-mfd.c   |  264 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/retu.h |   22 ++++
>  4 files changed, 296 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/mfd/retu-mfd.c
>  create mode 100644 include/linux/mfd/retu.h
> 
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index acab3ef..7528c5e 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -1044,6 +1044,15 @@ config MFD_PALMAS
>  	  If you say yes here you get support for the Palmas
>  	  series of PMIC chips from Texas Instruments.
>  
> +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
>  
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index d8ccb63..ad7879f 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -138,3 +138,4 @@ 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
> diff --git a/drivers/mfd/retu-mfd.c b/drivers/mfd/retu-mfd.c
> new file mode 100644
> index 0000000..7ff4a37
> --- /dev/null
> +++ b/drivers/mfd/retu-mfd.c
> @@ -0,0 +1,264 @@
> +/*
> + * 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");
> diff --git a/include/linux/mfd/retu.h b/include/linux/mfd/retu.h
> new file mode 100644
> index 0000000..1e2715d
> --- /dev/null
> +++ b/include/linux/mfd/retu.h
> @@ -0,0 +1,22 @@
> +/*
> + * 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 */
> -- 
> 1.7.2.5
> 
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