On 11/05/2015 07:37 PM, Timur Tabi wrote:
> Add the "sbsa32" command-line option to earlycon to specify that the
> pl011 registers should be accessed with 32-bit accessors only. This is
> SBSA platforms
>
> Similarly, also add the "zte" option for the ZTE UART. It's functionally
> similar to the standard PL011, but some registers are at different
> offsets.
>
> Normal console uses the "access_32b" field of the vendor data structure
> to determine whether the registers needs 32-bit accessors. Early console
> is used before the vendor data is available, so we need a different
> mechanism to choose the accessor.
>
> Example:
>
> earlycon=pl011,0x3ced1000,sbsa32
Perhaps I wasn't clear enough in my previous comments regarding this
approach; I see no benefit to re-using the pl011 earlycon definition.
Just define a completely new earlycon for sbsa32 (and zte):
EARLYCON_DECLARE(sbsa32, sbsa32_early_console_setup);
Example:
earlycon=sbsa32,0x3ced1000
Regards,
Peter Hurley
> Signed-off-by: Timur Tabi <timur@xxxxxxxxxxxxxx>
> ---
>
> This patch applies on top of Russell's 12-part amba-pl011.c patchset.
>
> drivers/tty/serial/amba-pl011.c | 46 +++++++++++++++++++++++++++++++++++++----
> 1 file changed, 42 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index 373b152..58eda89 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -2301,10 +2301,10 @@ static struct console amba_console = {
>
> static void pl011_putc(struct uart_port *port, int c)
> {
> - while (readl(port->membase + REG_FR) & UART01x_FR_TXFF)
> + while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
> ;
> - writeb(c, port->membase + REG_DR);
> - while (readl(port->membase + REG_FR) & UART01x_FR_BUSY)
> + writeb(c, port->membase + UART01x_DR);
> + while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
> ;
> }
>
> @@ -2315,13 +2315,51 @@ static void pl011_early_write(struct console *con, const char *s, unsigned n)
> uart_console_write(&dev->port, s, n, pl011_putc);
> }
>
> +static void pl011_putc_sbsa32(struct uart_port *port, int c)
> +{
> + while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
> + cpu_relax();
> + writel(c, port->membase + UART01x_DR);
> + while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
> + cpu_relax();
> +}
> +
> +static void pl011_early_write_sbsa32(struct console *con, const char *s, unsigned n)
> +{
> + struct earlycon_device *dev = con->data;
> +
> + uart_console_write(&dev->port, s, n, pl011_putc_sbsa32);
> +}
> +
> +static void pl011_putc_zte(struct uart_port *port, int c)
> +{
> + while (readl(port->membase + ZX_UART011_FR) & UART01x_FR_TXFF)
> + cpu_relax();
> + writel(c, port->membase + ZX_UART011_DR);
> + while (readl(port->membase + ZX_UART011_FR) & UART01x_FR_BUSY)
> + cpu_relax();
> +}
> +
> +static void pl011_early_write_zte(struct console *con, const char *s, unsigned n)
> +{
> + struct earlycon_device *dev = con->data;
> +
> + uart_console_write(&dev->port, s, n, pl011_putc_zte);
> +}
> +
> static int __init pl011_early_console_setup(struct earlycon_device *device,
> const char *opt)
> {
> if (!device->port.membase)
> return -ENODEV;
>
> - device->con->write = pl011_early_write;
> + if (strcmp(device->options, "sbsa32") == 0)
> + device->con->write = pl011_early_write_sbsa32;
> + else if (strcmp(device->options, "zte") == 0)
> + device->con->write = pl011_early_write_zte;
> + else
> + device->con->write = pl011_early_write;
> +
> return 0;
> }
> EARLYCON_DECLARE(pl011, pl011_early_console_setup);
>
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
