From 6ca6ca5d813845533bcaaaeb2ca59d0805a028ca Mon Sep 17 00:00:00 2001 From: Fabio Baltieri Date: Mon, 15 Aug 2011 16:19:30 +0200 Subject: [PATCH] powerpc/83xx: Add shutdown request support to MCU handling on MPC8349 MITX This patch add support for calling ctrl_alt_del() when the power button is pressed for more than about 2 seconds on some freescale MPC83xx evaluation boards and reference design. The code uses a kthread to poll the CTRL_BTN bit each second. Also change Kconfig entry of the driver to bool, as device's gpio registration is broken when loading as module. Tested on an MPC8315E RDB board. Signed-off-by: Fabio Baltieri Signed-off-by: Kumar Gala --- .../powerpc/platforms/83xx/mcu_mpc8349emitx.c | 58 ++++++++++++++++++- arch/powerpc/platforms/Kconfig | 2 +- 2 files changed, 58 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c b/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c index 70798ac911ef..ef6537b8ed33 100644 --- a/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c +++ b/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c @@ -21,6 +21,8 @@ #include #include #include +#include +#include #include #include @@ -30,6 +32,7 @@ */ #define MCU_REG_CTRL 0x20 #define MCU_CTRL_POFF 0x40 +#define MCU_CTRL_BTN 0x80 #define MCU_NUM_GPIO 2 @@ -42,13 +45,55 @@ struct mcu { static struct mcu *glob_mcu; +struct task_struct *shutdown_thread; +static int shutdown_thread_fn(void *data) +{ + int ret; + struct mcu *mcu = glob_mcu; + + while (!kthread_should_stop()) { + ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL); + if (ret < 0) + pr_err("MCU status reg read failed.\n"); + mcu->reg_ctrl = ret; + + + if (mcu->reg_ctrl & MCU_CTRL_BTN) { + i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL, + mcu->reg_ctrl & ~MCU_CTRL_BTN); + + ctrl_alt_del(); + } + + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(HZ); + } + + return 0; +} + +static ssize_t show_status(struct device *d, + struct device_attribute *attr, char *buf) +{ + int ret; + struct mcu *mcu = glob_mcu; + + ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL); + if (ret < 0) + return -ENODEV; + mcu->reg_ctrl = ret; + + return sprintf(buf, "%02x\n", ret); +} +static DEVICE_ATTR(status, S_IRUGO, show_status, NULL); + 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, + i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL, mcu->reg_ctrl | MCU_CTRL_POFF); mutex_unlock(&mcu->lock); } @@ -130,6 +175,13 @@ static int __devinit mcu_probe(struct i2c_client *client, dev_info(&client->dev, "will provide power-off service\n"); } + if (device_create_file(&client->dev, &dev_attr_status)) + dev_err(&client->dev, + "couldn't create device file for status\n"); + + shutdown_thread = kthread_run(shutdown_thread_fn, NULL, + "mcu-i2c-shdn"); + return 0; err: kfree(mcu); @@ -141,6 +193,10 @@ static int __devexit mcu_remove(struct i2c_client *client) struct mcu *mcu = i2c_get_clientdata(client); int ret; + kthread_stop(shutdown_thread); + + device_remove_file(&client->dev, &dev_attr_status); + if (glob_mcu == mcu) { ppc_md.power_off = NULL; glob_mcu = NULL; diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig index 9fdb9b6ab371..e4588721ef34 100644 --- a/arch/powerpc/platforms/Kconfig +++ b/arch/powerpc/platforms/Kconfig @@ -346,7 +346,7 @@ config SIMPLE_GPIO on-board peripherals. config MCU_MPC8349EMITX - tristate "MPC8349E-mITX MCU driver" + bool "MPC8349E-mITX MCU driver" depends on I2C && PPC_83xx select GENERIC_GPIO select ARCH_REQUIRE_GPIOLIB -- 2.20.1