Re: [PATCH] serial: cadence: Add generic earlycon support

From: Greg Kroah-Hartman
Date: Wed Sep 17 2014 - 16:59:20 EST


On Wed, Sep 17, 2014 at 03:44:58PM +0200, Michal Simek wrote:
> Hi Greg,
>
> On 09/10/2014 12:43 PM, Michal Simek wrote:
> > Add earlycon support for the cadence serial port.
> > This is based on recent patches:
> > "tty/serial: pl011: add generic earlycon support"
> > (sha1: 0d3c673e7881e691991b2a4745bd4f149603baa2)
> > "tty/serial: add arm/arm64 semihosting earlycon"
> > (sha1: d50d7269ebcb438afa346cdffce0f4e2a1b9e831)
> >
> > Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
> > ---
> >
> > Documentation/kernel-parameters.txt | 6 ++++++
> > drivers/tty/serial/Kconfig | 1 +
> > drivers/tty/serial/xilinx_uartps.c | 19 +++++++++++++++++++
> > 3 files changed, 26 insertions(+)
> >
> > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> > index a8eb6afce6a4..97055dc43167 100644
> > --- a/Documentation/kernel-parameters.txt
> > +++ b/Documentation/kernel-parameters.txt
> > @@ -921,6 +921,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> >
> > earlycon= [KNL] Output early console device and options.
> >
> > + cdns,<addr>
> > + Start an early, polled-mode console on a cadence serial
> > + port at the specified address. The cadence serial port
> > + must already be setup and configured. Options are not
> > + yet supported.
> > +
> > uart[8250],io,<addr>[,options]
> > uart[8250],mmio,<addr>[,options]
> > uart[8250],mmio32,<addr>[,options]
> > diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> > index b4d61e6bf28c..72fd2b6e2241 100644
> > --- a/drivers/tty/serial/Kconfig
> > +++ b/drivers/tty/serial/Kconfig
> > @@ -1411,6 +1411,7 @@ config SERIAL_XILINX_PS_UART_CONSOLE
> > bool "Cadence UART console support"
> > depends on SERIAL_XILINX_PS_UART=y
> > select SERIAL_CORE_CONSOLE
> > + select SERIAL_EARLYCON
> > help
> > Enable a Cadence UART port to be the system console.
> >
> > diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
> > index 01951d27cc03..675f3fe068f6 100644
> > --- a/drivers/tty/serial/xilinx_uartps.c
> > +++ b/drivers/tty/serial/xilinx_uartps.c
> > @@ -1051,6 +1051,25 @@ static void cdns_uart_console_putchar(struct uart_port *port, int ch)
> > cdns_uart_writel(ch, CDNS_UART_FIFO_OFFSET);
> > }
> >
> > +static void cdns_early_write(struct console *con, const char *s, unsigned n)
> > +{
> > + struct earlycon_device *dev = con->data;
> > +
> > + uart_console_write(&dev->port, s, n, cdns_uart_console_putchar);
> > +}
> > +
> > +static int __init cdns_early_console_setup(struct earlycon_device *device,
> > + const char *opt)
> > +{
> > + if (!device->port.membase)
> > + return -ENODEV;
> > +
> > + device->con->write = cdns_early_write;
> > +
> > + return 0;
> > +}
> > +EARLYCON_DECLARE(cdns, cdns_early_console_setup);
> > +
> > /**
> > * cdns_uart_console_write - perform write operation
> > * @co: Console handle
> > --
> > 1.8.2.3
> >
>
> Any problem with this patch?

Don't know, it's in my todo queue which is really long at the moment...
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