tty: uartclk value from serial_core exposed to sysfs (6915c0e4) · Commits · e / devices / android_kernel_sony_msm8998

Documentation/ABI/testing/sysfs-tty

+9 −0

Original line number	Original line	Diff line number	Diff line
	@@ -17,3 +17,12 @@ Description:
	device, like 'tty1'.		device, like 'tty1'.
	The file supports poll() to detect virtual		The file supports poll() to detect virtual
	console switches.		console switches.

			What: /sys/class/tty/ttyS0/uartclk
			Date: Sep 2012
			Contact: Tomas Hlavacek <tmshlvck@gmail.com>
			Description:
			Shows the current uartclk value associated with the
			UART port in serial_core, that is bound to TTY like ttyS0.
			uartclk = 16 * baud_base

drivers/tty/serial/serial_core.c

+32 −2

Original line number	Original line	Diff line number	Diff line
	@@ -2309,6 +2309,36 @@ struct tty_driver uart_console_device(struct console co, int *index)
	return p->tty_driver;		return p->tty_driver;
	}		}

			static ssize_t uart_get_attr_uartclk(struct device *dev,
			struct device_attribute attr, char buf)
			{
			int ret;

			struct tty_port *port = dev_get_drvdata(dev);
			struct uart_state *state = container_of(port, struct uart_state, port);
			mutex_lock(&state->port.mutex);
			ret = snprintf(buf, PAGE_SIZE, "%d\n", state->uart_port->uartclk);
			mutex_unlock(&state->port.mutex);

			return ret;
			}

			static DEVICE_ATTR(uartclk, S_IRUSR \| S_IRGRP, uart_get_attr_uartclk, NULL);

			static struct attribute *tty_dev_attrs[] = {
			&dev_attr_uartclk.attr,
			NULL,
			};

			static struct attribute_group tty_dev_attr_group = {
			.attrs = tty_dev_attrs,
			};

			static const struct attribute_group *tty_dev_attr_groups[] = {
			&tty_dev_attr_group,
			NULL
			};

	/**		/**
	* uart_add_one_port - attach a driver-defined port structure		* uart_add_one_port - attach a driver-defined port structure
	* @drv: pointer to the uart low level driver structure for this port		* @drv: pointer to the uart low level driver structure for this port
	@@ -2362,8 +2392,8 @@ int uart_add_one_port(struct uart_driver drv, struct uart_port uport)
	* Register the port whether it's detected or not. This allows		* Register the port whether it's detected or not. This allows
	* setserial to be used to alter this ports parameters.		* setserial to be used to alter this ports parameters.
	*/		*/
	tty_dev = tty_port_register_device(port, drv->tty_driver, uport->line,		tty_dev = tty_register_device_attr(drv->tty_driver, uport->line,
	uport->dev);		uport->dev, port, tty_dev_attr_groups);
	if (likely(!IS_ERR(tty_dev))) {		if (likely(!IS_ERR(tty_dev))) {
	device_set_wakeup_capable(tty_dev, 1);		device_set_wakeup_capable(tty_dev, 1);
	} else {		} else {

drivers/tty/tty_io.c

+59 −10

Original line number	Original line	Diff line number	Diff line
	@@ -3041,9 +3041,39 @@ static int tty_cdev_add(struct tty_driver *driver, dev_t dev,
	struct device tty_register_device(struct tty_driver driver, unsigned index,		struct device tty_register_device(struct tty_driver driver, unsigned index,
	struct device *device)		struct device *device)
	{		{
	struct device *ret;		return tty_register_device_attr(driver, index, device, NULL, NULL);
			}
			EXPORT_SYMBOL(tty_register_device);

			/**
			* tty_register_device_attr - register a tty device
			* @driver: the tty driver that describes the tty device
			* @index: the index in the tty driver for this tty device
			* @device: a struct device that is associated with this tty device.
			* This field is optional, if there is no known struct device
			* for this tty device it can be set to NULL safely.
			* @drvdata: Driver data to be set to device.
			* @attr_grp: Attribute group to be set on device.
			*
			* Returns a pointer to the struct device for this tty device
			* (or ERR_PTR(-EFOO) on error).
			*
			* This call is required to be made to register an individual tty device
			* if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If
			* that bit is not set, this function should not be called by a tty
			* driver.
			*
			* Locking: ??
			*/
			struct device tty_register_device_attr(struct tty_driver driver,
			unsigned index, struct device *device,
			void *drvdata,
			const struct attribute_group **attr_grp)
			{
	char name[64];		char name[64];
	dev_t dev = MKDEV(driver->major, driver->minor_start) + index;		dev_t devt = MKDEV(driver->major, driver->minor_start) + index;
			struct device *dev = NULL;
			int retval = -ENODEV;
	bool cdev = false;		bool cdev = false;

	if (index >= driver->num) {		if (index >= driver->num) {
	@@ -3058,19 +3088,38 @@ struct device tty_register_device(struct tty_driver driver, unsigned index,
	tty_line_name(driver, index, name);		tty_line_name(driver, index, name);

	if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) {		if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
	int error = tty_cdev_add(driver, dev, index, 1);		retval = tty_cdev_add(driver, devt, index, 1);
	if (error)		if (retval)
	return ERR_PTR(error);		goto error;
	cdev = true;		cdev = true;
	}		}

	ret = device_create(tty_class, device, dev, NULL, name);		dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (IS_ERR(ret) && cdev)		if (!dev) {
	cdev_del(&driver->cdevs[index]);		retval = -ENOMEM;
			goto error;
			}

	return ret;		dev->devt = devt;
			dev->class = tty_class;
			dev->parent = device;
			dev_set_name(dev, "%s", name);
			dev->groups = attr_grp;
			dev_set_drvdata(dev, drvdata);

			retval = device_register(dev);
			if (retval)
			goto error;

			return dev;

			error:
			put_device(dev);
			if (cdev)
			cdev_del(&driver->cdevs[index]);
			return ERR_PTR(retval);
	}		}
	EXPORT_SYMBOL(tty_register_device);		EXPORT_SYMBOL_GPL(tty_register_device_attr);

	/**		/**
	* tty_unregister_device - unregister a tty device		* tty_unregister_device - unregister a tty device

include/linux/tty.h

+4 −0

Original line number	Original line	Diff line number	Diff line
	@@ -412,6 +412,10 @@ extern int tty_register_driver(struct tty_driver *driver);
	extern int tty_unregister_driver(struct tty_driver *driver);		extern int tty_unregister_driver(struct tty_driver *driver);
	extern struct device tty_register_device(struct tty_driver driver,		extern struct device tty_register_device(struct tty_driver driver,
	unsigned index, struct device *dev);		unsigned index, struct device *dev);
			extern struct device tty_register_device_attr(struct tty_driver driver,
			unsigned index, struct device *device,
			void *drvdata,
			const struct attribute_group **attr_grp);
	extern void tty_unregister_device(struct tty_driver *driver, unsigned index);		extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
	extern int tty_read_raw_data(struct tty_struct tty, unsigned char bufp,		extern int tty_read_raw_data(struct tty_struct tty, unsigned char bufp,
	int buflen);		int buflen);