[i2c] [PATCH 2/2] i2c: MPC8349E-mITX Power Management and GPIO expander driver
Ben Dooks
ben-linux at fluff.org
Tue Sep 23 08:45:40 EST 2008
On Fri, Sep 19, 2008 at 10:03:54PM +0400, Anton Vorontsov wrote:
> On MPC8349E-mITX, MPC8315E-RDB and MPC837x-RDB boards there is a
> Freescale MC9S08QG8 (MCU) chip with the custom firmware
> pre-programmed. The chip is used to power-off the board by the
> software, and to control some GPIO pins.
I suppose there's no other place for this sort of thing to go at
the moment other than drivers/i2c/chips.
I've also a driver for a similar PMU fitted to a number
of our boards that provides basic gpio (wakeup sources) and some
minimalist power management (so isn't really fit for regulator
framwork) and isn't really a gpio chip (so drivers/gpio isn't
really the place for it either.)
> Signed-off-by: Anton Vorontsov <avorontsov at ru.mvista.com>
> ---
> drivers/i2c/chips/Kconfig | 11 ++
> drivers/i2c/chips/Makefile | 1 +
> drivers/i2c/chips/mcu_mpc8349emitx.c | 213 ++++++++++++++++++++++++++++++++++
> 3 files changed, 225 insertions(+), 0 deletions(-)
> create mode 100644 drivers/i2c/chips/mcu_mpc8349emitx.c
>
> diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig
> index a95cb94..1735682 100644
> --- a/drivers/i2c/chips/Kconfig
> +++ b/drivers/i2c/chips/Kconfig
> @@ -172,4 +172,15 @@ config MENELAUS
> and other features that are often used in portable devices like
> cell phones and PDAs.
>
> +config MCU_MPC8349EMITX
> + tristate "MPC8349E-mITX MCU driver"
> + depends on I2C && PPC_83xx
> + select GENERIC_GPIO
> + select ARCH_REQUIRE_GPIOLIB
> + help
> + Say Y here to enable soft power-off functionality on the Freescale
> + boards with the MPC8349E-mITX-compatible MCU chips. This driver will
> + also register MCU GPIOs with the generic GPIO API, so you'll able
> + to use MCU pins as GPIOs.
> +
> endmenu
> diff --git a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile
> index 39e3e69..ca520fa 100644
> --- a/drivers/i2c/chips/Makefile
> +++ b/drivers/i2c/chips/Makefile
> @@ -21,6 +21,7 @@ obj-$(CONFIG_ISP1301_OMAP) += isp1301_omap.o
> obj-$(CONFIG_TPS65010) += tps65010.o
> obj-$(CONFIG_MENELAUS) += menelaus.o
> obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o
> +obj-$(CONFIG_MCU_MPC8349EMITX) += mcu_mpc8349emitx.o
>
> ifeq ($(CONFIG_I2C_DEBUG_CHIP),y)
> EXTRA_CFLAGS += -DDEBUG
> diff --git a/drivers/i2c/chips/mcu_mpc8349emitx.c b/drivers/i2c/chips/mcu_mpc8349emitx.c
> new file mode 100644
> index 0000000..47b07b8
> --- /dev/null
> +++ b/drivers/i2c/chips/mcu_mpc8349emitx.c
> @@ -0,0 +1,213 @@
> +/*
> + * Power Management and GPIO expander driver for MPC8349E-mITX-compatible MCU
> + *
> + * Copyright (c) 2008 MontaVista Software, Inc.
> + *
> + * Author: Anton Vorontsov <avorontsov at ru.mvista.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/device.h>
> +#include <linux/mutex.h>
> +#include <linux/i2c.h>
> +#include <linux/gpio.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <asm/prom.h>
> +#include <asm/machdep.h>
> +
> +/*
> + * I don't have specifications for the MCU firmware, I found this register
> + * and bits positions by the trial&error method.
> + */
> +#define MCU_REG_CTRL 0x20
> +#define MCU_CTRL_POFF 0x40
> +
> +#define MCU_NUM_GPIO 2
> +
> +struct mcu {
> + struct mutex lock;
> + struct device_node *np;
> + struct i2c_client *client;
> + struct of_gpio_chip of_gc;
> + u8 reg_ctrl;
> +};
> +
> +static struct mcu *glob_mcu;
> +
> +static void mcu_power_off(void)
> +{
> + struct mcu *mcu = glob_mcu;
> +
> + pr_info("Sending power-off request to the MCU...\n");
> + mutex_lock(&mcu->lock);
> + i2c_smbus_write_byte_data(glob_mcu->client, MCU_REG_CTRL,
> + mcu->reg_ctrl | MCU_CTRL_POFF);
> + mutex_unlock(&mcu->lock);
> +}
> +
> +static void mcu_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
> +{
> + struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
> + struct mcu *mcu = container_of(of_gc, struct mcu, of_gc);
> + u8 bit = 1 << (4 + gpio);
> +
> + mutex_lock(&mcu->lock);
> + if (val)
> + mcu->reg_ctrl &= ~bit;
> + else
> + mcu->reg_ctrl |= bit;
> +
> + i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL, mcu->reg_ctrl);
> + mutex_unlock(&mcu->lock);
> +}
> +
> +static int mcu_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
> +{
> + mcu_gpio_set(gc, gpio, val);
> + return 0;
> +}
> +
> +static int mcu_gpiochip_add(struct mcu *mcu)
> +{
> + struct device_node *np;
> + struct of_gpio_chip *of_gc = &mcu->of_gc;
> + struct gpio_chip *gc = &of_gc->gc;
> + int ret;
> +
> + np = of_find_compatible_node(NULL, NULL, "fsl,mcu-mpc8349emitx");
> + if (!np)
> + return -ENODEV;
> +
> + gc->owner = THIS_MODULE;
> + gc->label = np->full_name;
> + gc->can_sleep = 1;
> + gc->ngpio = MCU_NUM_GPIO;
> + gc->base = -1;
> + gc->set = mcu_gpio_set;
> + gc->direction_output = mcu_gpio_dir_out;
> + of_gc->gpio_cells = 2;
> + of_gc->xlate = of_gpio_simple_xlate;
> +
> + np->data = of_gc;
> + mcu->np = np;
> +
> + /*
> + * We don't want to lose the node, its ->data and ->full_name...
> + * So, if succeeded, we don't put the node here.
> + */
> + ret = gpiochip_add(gc);
> + if (ret)
> + of_node_put(np);
> + return ret;
> +}
> +
> +static int mcu_gpiochip_remove(struct mcu *mcu)
> +{
> + int ret;
> +
> + ret = gpiochip_remove(&mcu->of_gc.gc);
> + if (ret)
> + return ret;
> + of_node_put(mcu->np);
> +
> + return 0;
> +}
> +
> +static int __devinit mcu_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct mcu *mcu;
> + int ret;
> +
> + mcu = kzalloc(sizeof(*mcu), GFP_KERNEL);
> + if (!mcu)
> + return -ENOMEM;
> +
> + mutex_init(&mcu->lock);
> + mcu->client = client;
> + i2c_set_clientdata(client, mcu);
> +
> + ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
> + if (ret < 0)
> + goto err;
> + mcu->reg_ctrl = ret;
> +
> + ret = mcu_gpiochip_add(mcu);
> + if (ret)
> + goto err;
> +
> + /* XXX: this is potentially racy, but there is no lock for ppc_md */
> + if (!ppc_md.power_off) {
> + glob_mcu = mcu;
> + ppc_md.power_off = mcu_power_off;
> + dev_info(&client->dev, "will provide power-off service\n");
> + }
> +
> + return 0;
> +err:
> + kfree(mcu);
> + return ret;
> +}
> +
> +static int __devexit mcu_remove(struct i2c_client *client)
> +{
> + struct mcu *mcu = i2c_get_clientdata(client);
> + int ret;
> +
> + if (glob_mcu == mcu) {
> + ppc_md.power_off = NULL;
> + glob_mcu = NULL;
> + }
> +
> + ret = mcu_gpiochip_remove(mcu);
> + if (ret)
> + return ret;
> + i2c_set_clientdata(client, NULL);
> + kfree(mcu);
> + return 0;
> +}
> +
> +static const struct i2c_device_id mcu_ids[] = {
> + { "mc9s08qg8-mpc8349emitx", },
> + { "mc9s08qg8-mpc8377rdb", },
> + { "mc9s08qg8-mpc8378rdb", },
> + { "mc9s08qg8-mpc8379rdb", },
> + { "mc9s08qg8-mpc8315rdb", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(i2c, mcu_ids);
> +
> +static struct i2c_driver mcu_driver = {
> + .driver = {
> + .name = "mcu-mpc8349emitx",
> + .owner = THIS_MODULE,
> + },
> + .probe = mcu_probe,
> + .remove = __devexit_p(mcu_remove),
> + .id_table = mcu_ids,
> +};
> +
> +static int __init mcu_init(void)
> +{
> + return i2c_add_driver(&mcu_driver);
> +}
> +module_init(mcu_init);
> +
> +static void __exit mcu_exit(void)
> +{
> + i2c_del_driver(&mcu_driver);
> +}
> +module_exit(mcu_exit);
> +
> +MODULE_DESCRIPTION("Power Management and GPIO expander driver for "
> + "MPC8349E-mITX-compatible MCU");
> +MODULE_AUTHOR("Anton Vorontsov <avorontsov at ru.mvista.com>");
> +MODULE_LICENSE("GPL");
> --
> 1.5.6.3
>
> _______________________________________________
> i2c mailing list
> i2c at lm-sensors.org
> http://lists.lm-sensors.org/mailman/listinfo/i2c
--
Ben (ben at fluff.org, http://www.fluff.org/)
'a smiley only costs 4 bytes'
More information about the Linuxppc-dev
mailing list