arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c

Source file repositories/reference/linux-study-clean/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c

File Facts

System
Linux kernel
Corpus path
arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c
Extension
.c
Size
4942 bytes
Lines
231
Domain
Architecture Layer
Bucket
arch/powerpc
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct mcu {
	struct mutex lock;
	struct i2c_client *client;
	struct gpio_chip gc;
	u8 reg_ctrl;
};

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 sysfs_emit(buf, "%02x\n", ret);
}
static DEVICE_ATTR(status, 0444, 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(mcu->client, MCU_REG_CTRL,
				  mcu->reg_ctrl | MCU_CTRL_POFF);
	mutex_unlock(&mcu->lock);
}

static int mcu_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
{
	struct mcu *mcu = gpiochip_get_data(gc);
	u8 bit = 1 << (4 + gpio);
	int ret;

	mutex_lock(&mcu->lock);
	if (val)
		mcu->reg_ctrl &= ~bit;
	else
		mcu->reg_ctrl |= bit;

	ret = i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL,
					mcu->reg_ctrl);
	mutex_unlock(&mcu->lock);

	return ret;
}

static int mcu_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
{
	return mcu_gpio_set(gc, gpio, val);
}

static int mcu_gpiochip_add(struct mcu *mcu)
{
	struct device *dev = &mcu->client->dev;
	struct gpio_chip *gc = &mcu->gc;

Annotation

Implementation Notes