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serial: uartps: Register own uart console and driver structures
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Every instance is registering own struct console and struct uart_driver
with minor number which corresponds to alias ID (or 0 now) and with 1 uart
port. The same alias ID is saved to tty_driver->name_base which is key
field for creating ttyPSX name.

Because name_base and minor number are setup already there is no need to
setup any port->line number because 0 is the right value.

Unfortunately this driver is setting up major number to 0 for using
dynamic assignment and kernel is allocating different major numbers for
every instance instead of using the same major and different minor
number.

~# ls -la /dev/ttyPS*
crw-------    1 root     root      252,   0 Jan  1 03:36 /dev/ttyPS0
crw--w----    1 root     root      253,   1 Jan  1 00:00 /dev/ttyPS1

When major number is not 0. For example 252 then major/minor
combinations are in expected form

~# ls -la /dev/ttyPS*
crw-------    1 root     root      252,   0 Jan  1 04:04 /dev/ttyPS0
crw--w----    1 root     root      252,   1 Jan  1 00:00 /dev/ttyPS1

Driver is not freeing struct cdns_uart_console in case that instance is
not used as console. The reason is that console is incorrectly unregistred
and "console [0] disabled" message will be shown.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Michal Simek authored and Greg Kroah-Hartman committed Sep 18, 2018
1 parent 427c8ae commit 024ca32
Showing 1 changed file with 55 additions and 38 deletions.
93 changes: 55 additions & 38 deletions drivers/tty/serial/xilinx_uartps.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,6 @@
#define CDNS_UART_TTY_NAME "ttyPS"
#define CDNS_UART_NAME "xuartps"
#define CDNS_UART_MAJOR 0 /* use dynamic node allocation */
#define CDNS_UART_MINOR 0 /* works best with devtmpfs */
#define CDNS_UART_NR_PORTS 2
#define CDNS_UART_FIFO_SIZE 64 /* FIFO size */
#define CDNS_UART_REGISTER_SPACE 0x1000
Expand Down Expand Up @@ -1100,8 +1099,6 @@ static const struct uart_ops cdns_uart_ops = {
#endif
};

static struct uart_driver cdns_uart_uart_driver;

#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
/**
* cdns_uart_console_putchar - write the character to the FIFO buffer
Expand Down Expand Up @@ -1241,16 +1238,6 @@ static int cdns_uart_console_setup(struct console *co, char *options)

return uart_set_options(port, co, baud, parity, bits, flow);
}

static struct console cdns_uart_console = {
.name = CDNS_UART_TTY_NAME,
.write = cdns_uart_console_write,
.device = uart_console_device,
.setup = cdns_uart_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1, /* Specified on the cmdline (e.g. console=ttyPS ) */
.data = &cdns_uart_uart_driver,
};
#endif /* CONFIG_SERIAL_XILINX_PS_UART_CONSOLE */

#ifdef CONFIG_PM_SLEEP
Expand Down Expand Up @@ -1382,9 +1369,6 @@ static const struct of_device_id cdns_uart_of_match[] = {
};
MODULE_DEVICE_TABLE(of, cdns_uart_of_match);

/* Temporary variable for storing number of instances */
static int instances;

/**
* cdns_uart_probe - Platform driver probe
* @pdev: Pointer to the platform device structure
Expand All @@ -1398,6 +1382,11 @@ static int cdns_uart_probe(struct platform_device *pdev)
struct resource *res;
struct cdns_uart *cdns_uart_data;
const struct of_device_id *match;
struct uart_driver *cdns_uart_uart_driver;
char *driver_name;
#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
struct console *cdns_uart_console;
#endif

cdns_uart_data = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_data),
GFP_KERNEL);
Expand All @@ -1407,6 +1396,12 @@ static int cdns_uart_probe(struct platform_device *pdev)
if (!port)
return -ENOMEM;

cdns_uart_uart_driver = devm_kzalloc(&pdev->dev,
sizeof(*cdns_uart_uart_driver),
GFP_KERNEL);
if (!cdns_uart_uart_driver)
return -ENOMEM;

/* Look for a serialN alias */
id = of_alias_get_id(pdev->dev.of_node, "serial");
if (id < 0)
Expand All @@ -1417,25 +1412,50 @@ static int cdns_uart_probe(struct platform_device *pdev)
return -ENODEV;
}

if (!cdns_uart_uart_driver.state) {
cdns_uart_uart_driver.owner = THIS_MODULE;
cdns_uart_uart_driver.driver_name = CDNS_UART_NAME;
cdns_uart_uart_driver.dev_name = CDNS_UART_TTY_NAME;
cdns_uart_uart_driver.major = CDNS_UART_MAJOR;
cdns_uart_uart_driver.minor = CDNS_UART_MINOR;
cdns_uart_uart_driver.nr = CDNS_UART_NR_PORTS;
/* There is a need to use unique driver name */
driver_name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s%d",
CDNS_UART_NAME, id);
if (!driver_name)
return -ENOMEM;

cdns_uart_uart_driver->owner = THIS_MODULE;
cdns_uart_uart_driver->driver_name = driver_name;
cdns_uart_uart_driver->dev_name = CDNS_UART_TTY_NAME;
cdns_uart_uart_driver->major = CDNS_UART_MAJOR;
cdns_uart_uart_driver->minor = id;
cdns_uart_uart_driver->nr = 1;

#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
cdns_uart_uart_driver.cons = &cdns_uart_console;
cdns_uart_console = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_console),
GFP_KERNEL);
if (!cdns_uart_console)
return -ENOMEM;

strncpy(cdns_uart_console->name, CDNS_UART_TTY_NAME,
sizeof(cdns_uart_console->name));
cdns_uart_console->index = id;
cdns_uart_console->write = cdns_uart_console_write;
cdns_uart_console->device = uart_console_device;
cdns_uart_console->setup = cdns_uart_console_setup;
cdns_uart_console->flags = CON_PRINTBUFFER;
cdns_uart_console->data = cdns_uart_uart_driver;
cdns_uart_uart_driver->cons = cdns_uart_console;
#endif

rc = uart_register_driver(&cdns_uart_uart_driver);
if (rc < 0) {
dev_err(&pdev->dev, "Failed to register driver\n");
return rc;
}
rc = uart_register_driver(cdns_uart_uart_driver);
if (rc < 0) {
dev_err(&pdev->dev, "Failed to register driver\n");
return rc;
}

cdns_uart_data->cdns_uart_driver = &cdns_uart_uart_driver;
cdns_uart_data->cdns_uart_driver = cdns_uart_uart_driver;

/*
* Setting up proper name_base needs to be done after uart
* registration because tty_driver structure is not filled.
* name_base is 0 by default.
*/
cdns_uart_uart_driver->tty_driver->name_base = id;

match = of_match_node(cdns_uart_of_match, pdev->dev.of_node);
if (match && match->data) {
Expand Down Expand Up @@ -1506,7 +1526,6 @@ static int cdns_uart_probe(struct platform_device *pdev)
port->flags = UPF_BOOT_AUTOCONF;
port->ops = &cdns_uart_ops;
port->fifosize = CDNS_UART_FIFO_SIZE;
port->line = id;

/*
* Register the port.
Expand Down Expand Up @@ -1537,7 +1556,7 @@ static int cdns_uart_probe(struct platform_device *pdev)
console_port = port;
#endif

rc = uart_add_one_port(&cdns_uart_uart_driver, port);
rc = uart_add_one_port(cdns_uart_uart_driver, port);
if (rc) {
dev_err(&pdev->dev,
"uart_add_one_port() failed; err=%i\n", rc);
Expand All @@ -1547,11 +1566,10 @@ static int cdns_uart_probe(struct platform_device *pdev)
#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
/* This is not port which is used for console that's why clean it up */
if (console_port == port &&
!(cdns_uart_uart_driver.cons->flags & CON_ENABLED))
!(cdns_uart_uart_driver->cons->flags & CON_ENABLED))
console_port = NULL;
#endif

instances++;
return 0;

err_out_pm_disable:
Expand All @@ -1567,8 +1585,8 @@ static int cdns_uart_probe(struct platform_device *pdev)
err_out_clk_dis_pclk:
clk_disable_unprepare(cdns_uart_data->pclk);
err_out_unregister_driver:
if (!instances)
uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
uart_unregister_driver(cdns_uart_data->cdns_uart_driver);

return rc;
}

Expand Down Expand Up @@ -1602,8 +1620,7 @@ static int cdns_uart_remove(struct platform_device *pdev)
console_port = NULL;
#endif

if (!--instances)
uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
return rc;
}

Expand Down

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