On Wed, Feb 09, 2011 at 10:58:13AM +0100, Tobias Klauser wrote:
> With the recent switch of the (currently still out-of-tree) Nios2 Linux
> port to devicetree we want to be able to retreive the resources and
> properties from dts.
>
> The old method to retreive resources and properties from platform data
> is still supported.
>
> Signed-off-by: Tobias Klauser <[email protected]>
> ---
> .../devicetree/bindings/serial/altera_uart.txt | 7 +++
> drivers/tty/serial/altera_uart.c | 47
> ++++++++++++++++++--
> 2 files changed, 50 insertions(+), 4 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/serial/altera_uart.txt
>
> diff --git a/Documentation/devicetree/bindings/serial/altera_uart.txt
> b/Documentation/devicetree/bindings/serial/altera_uart.txt
> new file mode 100644
> index 0000000..2ab151c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/serial/altera_uart.txt
> @@ -0,0 +1,7 @@
> +Altera UART
> +
> +Required properties:
> +- compatible : should be "ALTR,uart-1.0"
> +
> +Optional properties:
> +- clock-frequency : frequency of the clock input to the UART
> diff --git a/drivers/tty/serial/altera_uart.c
> b/drivers/tty/serial/altera_uart.c
> index 3a57352..5b46ca7 100644
> --- a/drivers/tty/serial/altera_uart.c
> +++ b/drivers/tty/serial/altera_uart.c
> @@ -24,6 +24,7 @@
> #include <linux/serial.h>
> #include <linux/serial_core.h>
> #include <linux/platform_device.h>
> +#include <linux/of.h>
> #include <linux/io.h>
> #include <linux/altera_uart.h>
>
> @@ -507,6 +508,34 @@ static struct uart_driver altera_uart_driver = {
> .cons = ALTERA_UART_CONSOLE,
> };
>
> +#ifdef CONFIG_OF
> +static int altera_uart_get_uartclk(struct platform_device *pdev,
> + struct uart_port *port)
> +{
> + const __be32 *clk = of_get_property(pdev->dev.of_node,
> "clock-frequency", NULL);
> +
> + if (!clk)
> + return -ENODEV;
> +
> + port->uartclk = be32_to_cpup(clk);
> +
> + return 0;
> +}
> +#else
> +static int altera_uart_get_uartclk(struct platform_device *pdev,
> + struct uart_port *port)
> +{
> + struct altera_uart_platform_uart *platp = pdev->dev.platform_data;
> +
> + if (!platp)
> + return -ENODEV;
> +
> + port->uartclk = platp->uartclk;
> +
> + return 0;
> +}
> +#endif /* CONFIG_OF */
This either/or situation isn't really desirable. The driver should be
written so that platform_data works regardless of whether or not
CONFIG_OF is set. So, if the of_node pointer is set, use it to get
the configuration, but fall back to platform data if it is NULL.
> +
> static int __devinit altera_uart_probe(struct platform_device *pdev)
> {
> struct altera_uart_platform_uart *platp = pdev->dev.platform_data;
> @@ -514,6 +543,7 @@ static int __devinit altera_uart_probe(struct
> platform_device *pdev)
> struct resource *res_mem;
> struct resource *res_irq;
> int i = pdev->id;
> + int ret;
>
> /* -1 emphasizes that the platform must have one port, no .N suffix */
> if (i == -1)
> @@ -538,6 +568,10 @@ static int __devinit altera_uart_probe(struct
> platform_device *pdev)
> else if (platp->irq)
> port->irq = platp->irq;
>
> + ret = altera_uart_get_uartclk(pdev, port);
> + if (ret)
> + return ret;
> +
> port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
> if (!port->membase)
> return -ENOMEM;
> @@ -550,7 +584,6 @@ static int __devinit altera_uart_probe(struct
> platform_device *pdev)
> port->line = i;
> port->type = PORT_ALTERA_UART;
> port->iotype = SERIAL_IO_MEM;
> - port->uartclk = platp->uartclk;
> port->ops = &altera_uart_ops;
> port->flags = UPF_BOOT_AUTOCONF;
>
> @@ -573,13 +606,19 @@ static int __devexit altera_uart_remove(struct
> platform_device *pdev)
> return 0;
> }
>
> +static struct of_device_id altera_uart_match[] = {
> + { .compatible = "altr,uart-1.0", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, altera_uart_match);
Need to protect the MODULE_DEVICE_TABLE with #ifdef/#endif. You don't
want to advertise device tree support when CONFIG_OF isn't selected.
> +
> static struct platform_driver altera_uart_platform_driver = {
> .probe = altera_uart_probe,
> .remove = __devexit_p(altera_uart_remove),
> .driver = {
> - .name = DRV_NAME,
> - .owner = THIS_MODULE,
> - .pm = NULL,
> + .name = DRV_NAME,
> + .owner = THIS_MODULE,
> + .of_match_table = altera_uart_match,
> },
> };
>
> --
> 1.7.0.4
>
_______________________________________________
devicetree-discuss mailing list
[email protected]
https://lists.ozlabs.org/listinfo/devicetree-discuss
