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Subject[PATCH v4 2/7] tty/serial: meson_uart: update to stable bindings
Date
From: Helmut Klein <hgkr.klein@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.klein@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@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);
+
+ port->uartclk = clk_get_rate(clk_baud);
+
+ 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);
--
1.9.1
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