On 2014-08-08 at 13:32:03 +0200, Matthias Brugger <matthias.bgg@xxxxxxxxx> wrote:
> This patch adds support for the UART block found on Mediatek SoCs.
> The device has a highspeed register which influences the calcualtion of the
> divisor. The chip lacks support for some baudrates. When requested, we set the
> divisor to the next smaller baudrate and adjust the c_cflag accordingly.
>
> Signed-off-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> ---
> drivers/tty/serial/8250/8250_mtk.c | 296 ++++++++++++++++++++++++++++++++++++
> drivers/tty/serial/8250/Kconfig | 7 +
> drivers/tty/serial/8250/Makefile | 1 +
> 3 files changed, 304 insertions(+)
> create mode 100644 drivers/tty/serial/8250/8250_mtk.c
>
> diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
> new file mode 100644
> index 0000000..d63080b
> --- /dev/null
> +++ b/drivers/tty/serial/8250/8250_mtk.c
> @@ -0,0 +1,296 @@
[...]
> +static int mtk8250_probe(struct platform_device *pdev)
> +{
> + struct uart_8250_port uart = {};
> + struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> + struct mtk8250_data *data;
> + int err;
> +
> + if (!regs || !irq) {
> + dev_err(&pdev->dev, "no registers/irq defined\n");
> + return -EINVAL;
> + }
> +
> + spin_lock_init(&uart.port.lock);
> + uart.port.mapbase = regs->start;
> + uart.port.irq = irq->start;
> + uart.port.pm = mtk8250_do_pm;
> + uart.port.type = PORT_16550;
> + uart.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
> + uart.port.dev = &pdev->dev;
> +
> + uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
> + resource_size(regs));
> + if (!uart.port.membase)
> + return -ENOMEM;
You can use devm_ioremap_resource here and get rid of the check for
!regs above, since devm_ioremap_resource already does that.
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
...
uart.port.membase = devm_ioremap_resource(&pdev->dev, regs);
if (IS_ERR(uart.port.membase))
return PTR_ERR(uart.port.membase);
> +
> + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
I'd suggest to move this kzalloc and the ioremap before the uart.port
initialization part above, so you can error out early in case of any
failure.
> +
> + uart.port.iotype = UPIO_MEM32;
> + uart.port.regshift = 2;
> + uart.port.private_data = data;
> + uart.port.set_termios = mtk8250_set_termios;
> +
> + if (pdev->dev.of_node) {
> + err = mtk8250_probe_of(&uart.port, data);
> + if (err)
> + return err;
> + } else
> + return -ENODEV;
This could also be moved up, directly below devm_kzalloc.
> +
> + /* Disable Rate Fix function */
> + writel(0x0, uart.port.membase +
> + (MTK_UART_RATE_FIX << uart.port.regshift));
> +
> + data->line = serial8250_register_8250_port(&uart);
> + if (data->line < 0)
> + return data->line;
> +
> + platform_set_drvdata(pdev, data);
> +
> + pm_runtime_set_active(&pdev->dev);
> + pm_runtime_enable(&pdev->dev);
> +
> + return 0;
> +}
> +
> +static int mtk8250_remove(struct platform_device *pdev)
> +{
> + struct mtk8250_data *data = platform_get_drvdata(pdev);
> +
> + pm_runtime_get_sync(&pdev->dev);
> +
> + serial8250_unregister_port(data->line);
> + if (!IS_ERR(data->clk)) {
> + clk_disable_unprepare(data->clk);
> + clk_put(data->clk);
> + }
> +
> + pm_runtime_disable(&pdev->dev);
> + pm_runtime_put_noidle(&pdev->dev);
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int mtk8250_suspend(struct device *dev)
> +{
> + struct mtk8250_data *data = dev_get_drvdata(dev);
> +
> + serial8250_suspend_port(data->line);
> +
> + return 0;
> +}
> +
> +static int mtk8250_resume(struct device *dev)
> +{
> + struct mtk8250_data *data = dev_get_drvdata(dev);
> +
> + serial8250_resume_port(data->line);
> +
> + return 0;
> +}
> +#endif /* CONFIG_PM_SLEEP */
> +
> +#ifdef CONFIG_PM_RUNTIME
> +static int mtk8250_runtime_suspend(struct device *dev)
> +{
> + struct mtk8250_data *data = dev_get_drvdata(dev);
> +
> + if (!IS_ERR(data->clk))
> + clk_disable_unprepare(data->clk);
> +
> + return 0;
> +}
> +
> +static int mtk8250_runtime_resume(struct device *dev)
> +{
> + struct mtk8250_data *data = dev_get_drvdata(dev);
> +
> + if (!IS_ERR(data->clk))
> + clk_prepare_enable(data->clk);
> +
> + return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops mtk8250_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(mtk8250_suspend, mtk8250_resume)
> + SET_RUNTIME_PM_OPS(mtk8250_runtime_suspend, mtk8250_runtime_resume,
> + NULL)
> +};
> +
> +static const struct of_device_id mtk8250_of_match[] = {
> + { .compatible = "mediatek,mt6577-uart" },
> + { /* Sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, mtk8250_of_match);
> +
> +static struct platform_driver mtk8250_platform_driver = {
> + .driver = {
> + .name = "mt6577-uart",
> + .owner = THIS_MODULE,
This doesn't need to be set here,
module_platform_driver/platform_driver_register take care of setting it.
> + .pm = &mtk8250_pm_ops,
> + .of_match_table = mtk8250_of_match,
> + },
> + .probe = mtk8250_probe,
> + .remove = mtk8250_remove,
> +};
> +module_platform_driver(mtk8250_platform_driver);
> +
> +MODULE_AUTHOR("Matthias Brugger");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Mediatek 8250 serial port driver");
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