Re: [RESEND PATCH v3 2/4] mfd: introduce retu-mfd driver

From: Tony Lindgren
Date: Tue Nov 20 2012 - 13:34:19 EST


* Aaro Koskinen <aaro.koskinen@xxxxxx> [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@xxxxxxxxxxxxxxx
> Acked-by: Felipe Balbi <balbi@xxxxxx>
> Acked-by: Tony Lindgren <tony@xxxxxxxxxxx>
> Signed-off-by: Aaro Koskinen <aaro.koskinen@xxxxxx>
> ---
> 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 YrjÃlÃ, 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 YrjÃlÃ");
> +MODULE_AUTHOR("David Weinehall");
> +MODULE_AUTHOR("Mikko Ylinen");
> +MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@xxxxxx>");
> +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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