On Fri, 2017-06-09 at 11:49 +0200, Neil Armstrong wrote:
> From: Helmut Klein <hgkr.kl...@gmail.com>
>
> This patch handle the stable UART bindings but also keeps compatibility
> with the legacy non-stable bindings until all boards uses them.
>
> Signed-off-by: Helmut Klein <hgkr.kl...@gmail.com>
> Signed-off-by: Neil Armstrong <narmstr...@baylibre.com>
> ---
> drivers/tty/serial/meson_uart.c | 109 +++++++++++++++++++++++++++++++++++++
> ---
> 1 file changed, 103 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
> index 60f1679..d2c8136 100644
> --- a/drivers/tty/serial/meson_uart.c
> +++ b/drivers/tty/serial/meson_uart.c
> @@ -579,8 +579,12 @@ static void meson_serial_early_console_write(struct
> console *co,
> device->con->write = meson_serial_early_console_write;
> return 0;
> }
> +/* Legacy bindings, should be removed when no more used */
> OF_EARLYCON_DECLARE(meson, "amlogic,meson-uart",
> meson_serial_early_console_setup);
> +/* Stable bindings */
> +OF_EARLYCON_DECLARE(meson, "amlogic,meson-ao-uart",
> + meson_serial_early_console_setup);
>
> #define MESON_SERIAL_CONSOLE (&meson_serial_console)
> #else
> @@ -595,11 +599,95 @@ static void meson_serial_early_console_write(struct
> console *co,
> .cons = MESON_SERIAL_CONSOLE,
> };
>
> +/*
> + * This function gets clocks in the legacy non-stable DT bindings.
> + * This code will be remove once all the platforms switch to the
> + * new DT bindings.
> + */
> +static int meson_uart_probe_clocks_legacy(struct platform_device *pdev,
> + struct uart_port *port)
> +{
> + struct clk *clk = NULL;
> + int ret;
> +
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(clk))
> + return PTR_ERR(clk);
> +
> + ret = clk_prepare_enable(clk);
> + if (ret) {
> + dev_err(&pdev->dev, "couldn't enable clk\n");
> + return ret;
> + }
> +
> + devm_add_action_or_reset(&pdev->dev,
> + (void(*)(void *))clk_disable_unprepare,
> + clk);
> +
> + port->uartclk = clk_get_rate(clk);
> +
> + return 0;
> +}
> +
> +static int meson_uart_probe_clocks(struct platform_device *pdev,
> + struct uart_port *port)
> +{
> + struct clk *clk_xtal = NULL;
> + struct clk *clk_pclk = NULL;
> + struct clk *clk_baud = NULL;
> + int ret;
> +
> + clk_pclk = devm_clk_get(&pdev->dev, "pclk");
> + if (IS_ERR(clk_pclk))
> + return PTR_ERR(clk_pclk);
> +
> + clk_xtal = devm_clk_get(&pdev->dev, "xtal");
> + if (IS_ERR(clk_xtal))
> + return PTR_ERR(clk_xtal);
> +
> + clk_baud = devm_clk_get(&pdev->dev, "baud");
> + if (IS_ERR(clk_xtal))
> + return PTR_ERR(clk_baud);
> +
> + ret = clk_prepare_enable(clk_pclk);
> + if (ret) {
> + dev_err(&pdev->dev, "couldn't enable pclk\n");
> + return ret;
> + }
> +
> + devm_add_action_or_reset(&pdev->dev,
> + (void(*)(void *))clk_disable_unprepare,
> + clk_pclk);
> +
> + ret = clk_prepare_enable(clk_xtal);
> + if (ret) {
> + dev_err(&pdev->dev, "couldn't enable xtal\n");
> + return ret;
> + }
> +
> + devm_add_action_or_reset(&pdev->dev,
> + (void(*)(void *))clk_disable_unprepare,
> + clk_xtal);
> +
> + ret = clk_prepare_enable(clk_baud);
> + if (ret) {
> + dev_err(&pdev->dev, "couldn't enable baud clk\n");
> + return ret;
> + }
> +
> + devm_add_action_or_reset(&pdev->dev,
> + (void(*)(void *))clk_disable_unprepare,
> + clk_baud);
It's not critical but there is a lot of duplication here. Should we add an
helper function doing "get, prepare_enable, add_reset_action" with the clock
name as argument ?
Apart from this:
Reviewed-by: Jerome Brunet <jbru...@baylibre.com>
> +
> + port->uartclk = clk_get_rate(clk_baud);
This was already like this, but I wonder if we should store the *clk instead of
caching the rate. Then call get_rate when appropriate
Could be done in separate patch.
> +
> + return 0;
> +}
> +
> static int meson_uart_probe(struct platform_device *pdev)
> {
> struct resource *res_mem, *res_irq;
> struct uart_port *port;
> - struct clk *clk;
> int ret = 0;
>
> if (pdev->dev.of_node)
> @@ -625,11 +713,15 @@ static int meson_uart_probe(struct platform_device
> *pdev)
> if (!port)
> return -ENOMEM;
>
> - clk = clk_get(&pdev->dev, NULL);
> - if (IS_ERR(clk))
> - return PTR_ERR(clk);
> + /* Use legacy way until all platforms switch to new bindings */
> + if (of_device_is_compatible(pdev->dev.of_node, "amlogic,meson-uart"))
> + ret = meson_uart_probe_clocks_legacy(pdev, port);
> + else
> + ret = meson_uart_probe_clocks(pdev, port);
> +
> + if (ret)
> + return ret;
>
> - port->uartclk = clk_get_rate(clk);
> port->iotype = UPIO_MEM;
> port->mapbase = res_mem->start;
> port->irq = res_irq->start;
> @@ -668,9 +760,14 @@ static int meson_uart_remove(struct platform_device
> *pdev)
> return 0;
> }
>
> -
> static const struct of_device_id meson_uart_dt_match[] = {
> + /* Legacy bindings, should be removed when no more used */
> { .compatible = "amlogic,meson-uart" },
> + /* Stable bindings */
> + { .compatible = "amlogic,meson6-uart" },
> + { .compatible = "amlogic,meson8-uart" },
> + { .compatible = "amlogic,meson8b-uart" },
> + { .compatible = "amlogic,meson-gx-uart" },
> { /* sentinel */ },
> };
> MODULE_DEVICE_TABLE(of, meson_uart_dt_match);
