Revert "serial: uartps: Register own uart console and driver structures"

commit 18cc7ac8a28e28cd005c2475f52576cfe10cabfb upstream.

This reverts commit 024ca329bfb9a948f76eaff3243e21b7e70182f2.

As Johan says, this driver needs a lot more work and these changes are
only going in the wrong direction:
  https://lkml.kernel.org/r/20190523091839.GC568@localhost

Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1ee35667e36a8efddee381df5fe495ad65f4d15c.1585905873.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index ec5e6df..fe098cf 100644 (file)
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -31,6 +31,7 @@
 #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     16
 #define CDNS_UART_FIFO_SIZE    64      /* FIFO size */
 #define CDNS_UART_REGISTER_SPACE       0x1000
@@ -1118,6 +1119,8 @@ 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
@@ -1257,6 +1260,16 @@ 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
@@ -1388,6 +1401,9 @@ 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
@@ -1401,11 +1417,6 @@ 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);
@@ -1415,12 +1426,6 @@ 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)
@@ -1431,50 +1436,25 @@ static int cdns_uart_probe(struct platform_device *pdev)
                return -ENODEV;
        }
 
-       /* 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;
-
+       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;
 #ifdef CONFIG_SERIAL_XILINX_PS_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;
+               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;
-
-       /*
-        * 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;
+       cdns_uart_data->cdns_uart_driver = &cdns_uart_uart_driver;
 
        match = of_match_node(cdns_uart_of_match, pdev->dev.of_node);
        if (match && match->data) {
@@ -1551,6 +1531,7 @@ 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.
@@ -1582,7 +1563,7 @@ 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);
@@ -1592,12 +1573,15 @@ 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
 
        cdns_uart_data->cts_override = of_property_read_bool(pdev->dev.of_node,
                                                             "cts-override");
+
+       instances++;
+
        return 0;
 
 err_out_pm_disable:
@@ -1613,8 +1597,8 @@ err_out_clk_disable:
 err_out_clk_dis_pclk:
        clk_disable_unprepare(cdns_uart_data->pclk);
 err_out_unregister_driver:
-       uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
-
+       if (!instances)
+               uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
        return rc;
 }
 
@@ -1649,7 +1633,8 @@ static int cdns_uart_remove(struct platform_device *pdev)
                console_port = NULL;
 #endif
 
-       uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
+       if (!--instances)
+               uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
        return rc;
 }