lkml.org 
[lkml]   [2018]   [Sep]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 06/10] serial: uartps: Move register to probe based on run time detection
Date
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 <michal.simek@xilinx.com>
---

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
\
 
 \ /
  Last update: 2018-09-03 15:12    [W:0.067 / U:14.876 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site