Commit 6915c0e4 authored by Tomas Hlavacek's avatar Tomas Hlavacek Committed by Greg Kroah-Hartman

tty: uartclk value from serial_core exposed to sysfs

Added file /sys/devices/.../tty/ttySX/uartclk to allow reading
uartclk value in struct uart_port in serial_core via sysfs.

tty_register_device() has been generalized and refactored in order
to add support for setting drvdata and attribute_group to the device.
Signed-off-by: default avatarTomas Hlavacek <tmshlvck@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d83b5425
......@@ -17,3 +17,12 @@ Description:
device, like 'tty1'.
The file supports poll() to detect virtual
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
......@@ -2309,6 +2309,36 @@ struct tty_driver *uart_console_device(struct console *co, int *index)
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
* @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
* setserial to be used to alter this ports parameters.
*/
tty_dev = tty_port_register_device(port, drv->tty_driver, uport->line,
uport->dev);
tty_dev = tty_register_device_attr(drv->tty_driver, uport->line,
uport->dev, port, tty_dev_attr_groups);
if (likely(!IS_ERR(tty_dev))) {
device_set_wakeup_capable(tty_dev, 1);
} else {
......
......@@ -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 *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];
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;
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);
if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
int error = tty_cdev_add(driver, dev, index, 1);
if (error)
return ERR_PTR(error);
retval = tty_cdev_add(driver, devt, index, 1);
if (retval)
goto error;
cdev = true;
}
ret = device_create(tty_class, device, dev, NULL, name);
if (IS_ERR(ret) && cdev)
cdev_del(&driver->cdevs[index]);
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev) {
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
......
......@@ -412,6 +412,10 @@ extern int tty_register_driver(struct tty_driver *driver);
extern int tty_unregister_driver(struct tty_driver *driver);
extern struct device *tty_register_device(struct tty_driver *driver,
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 int tty_read_raw_data(struct tty_struct *tty, unsigned char *bufp,
int buflen);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment