Register uart driver in probe to be able to register one device with unique major/minor separately. Also calculate number of instances of this driver to be able to call uart_unregister_driver() when there is no instance.
Signed-off-by: Michal Simek <[email protected]> --- Changes in v3: - Fix uart_unregister_driver() in error path or when driver is removed. - Change commit message Changes in v2: - Remove nr field logic Discussed here: https://patchwork.kernel.org/patch/9738445/ The same solution is done in pl011 driver. --- drivers/tty/serial/xilinx_uartps.c | 42 +++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 19 deletions(-) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index a3e97ccb376d..54735a7f9960 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -1393,6 +1393,9 @@ static int __maybe_unused cdns_runtime_resume(struct device *dev) }; 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 @@ -1425,6 +1428,14 @@ static int cdns_uart_probe(struct platform_device *pdev) return -ENODEV; } + if (!cdns_uart_uart_driver.state) { + 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; match = of_match_node(cdns_uart_of_match, pdev->dev.of_node); @@ -1442,7 +1453,8 @@ static int cdns_uart_probe(struct platform_device *pdev) } if (IS_ERR(cdns_uart_data->pclk)) { dev_err(&pdev->dev, "pclk clock not found.\n"); - return PTR_ERR(cdns_uart_data->pclk); + rc = PTR_ERR(cdns_uart_data->pclk); + goto err_out_unregister_driver; } cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "uart_clk"); @@ -1453,13 +1465,14 @@ static int cdns_uart_probe(struct platform_device *pdev) } if (IS_ERR(cdns_uart_data->uartclk)) { dev_err(&pdev->dev, "uart_clk clock not found.\n"); - return PTR_ERR(cdns_uart_data->uartclk); + rc = PTR_ERR(cdns_uart_data->uartclk); + goto err_out_unregister_driver; } rc = clk_prepare_enable(cdns_uart_data->pclk); if (rc) { dev_err(&pdev->dev, "Unable to enable pclk clock.\n"); - return rc; + goto err_out_unregister_driver; } rc = clk_prepare_enable(cdns_uart_data->uartclk); if (rc) { @@ -1538,6 +1551,7 @@ static int cdns_uart_probe(struct platform_device *pdev) console_port = NULL; #endif + instances++; return 0; err_out_pm_disable: @@ -1552,7 +1566,9 @@ static int cdns_uart_probe(struct platform_device *pdev) clk_disable_unprepare(cdns_uart_data->uartclk); 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); return rc; } @@ -1580,6 +1596,8 @@ static int cdns_uart_remove(struct platform_device *pdev) pm_runtime_disable(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); pm_runtime_dont_use_autosuspend(&pdev->dev); + if (!--instances) + uart_unregister_driver(cdns_uart_data->cdns_uart_driver); return rc; } @@ -1595,28 +1613,14 @@ static int cdns_uart_remove(struct platform_device *pdev) static int __init cdns_uart_init(void) { - int retval = 0; - - /* Register the cdns_uart driver with the serial core */ - retval = uart_register_driver(&cdns_uart_uart_driver); - if (retval) - return retval; - /* Register the platform driver */ - retval = platform_driver_register(&cdns_uart_platform_driver); - if (retval) - uart_unregister_driver(&cdns_uart_uart_driver); - - return retval; + return platform_driver_register(&cdns_uart_platform_driver); } static void __exit cdns_uart_exit(void) { /* Unregister the platform driver */ platform_driver_unregister(&cdns_uart_platform_driver); - - /* Unregister the cdns_uart driver */ - uart_unregister_driver(&cdns_uart_uart_driver); } arch_initcall(cdns_uart_init); -- 1.9.1
