[PATCH v3] lib: utils/serial: Update Shakti UART based on latest implementation

[Prasanna Thandabani]

Sure Anup,

That's the ideal way for a longer run. Thanks for applying the patch.

Thanks
PT

On Wed, Jul 20, 2022 at 10:13 AM Anup Patel <anup at brainfault.org> wrote:
>
> On Fri, Jul 8, 2022 at 5:23 PM Anup Patel <apatel at ventanamicro.com> wrote:
> >
> > From: Prasanna T <ptprasanna at gmail.com>
> >
> > The age old version of Shakti UART was upgraded long back, but we missed
> > updating the driver in OpenSBI. The old version of UART is not supported
> > anymore, hence removed the inline comment which is also outdated now.
> >
> > Signed-off-by: Prasanna T <ptprasanna at gmail.com>
> > Signed-off-by: Anup Patel <apatel at ventanamicro.com>
>
> @Prasanna, Please make sure that Shakti UART compatible string is
> documented in the upstream Linux kernel. This time it's okay since there
> is no HW with the old version of Shakti UART but subsequent changes to
> Shakti UART should require a new compatible string.
>
> Applied this patch to the riscv/opensbi repo.
>
> Thanks,
> Anup
>
> > ---
> > Changes since v2:
> >  - Updated patch subject and description
> >  - Minor fix in shakti_uart_getc()
> > ---
> >  lib/utils/serial/shakti-uart.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/lib/utils/serial/shakti-uart.c b/lib/utils/serial/shakti-uart.c
> > index 5f2fe75..3556935 100644
> > --- a/lib/utils/serial/shakti-uart.c
> > +++ b/lib/utils/serial/shakti-uart.c
> > @@ -19,21 +19,21 @@
> >  #define REG_RX_THRES   0x20
> >
> >  #define UART_TX_FULL  0x2
> > +#define UART_RX_NOT_EMPTY 0x4
> >  #define UART_RX_FULL  0x8
> >
> >  static volatile char *uart_base;
> >
> >  static void shakti_uart_putc(char ch)
> >  {
> > -       while((readw(uart_base + REG_STATUS) & UART_TX_FULL))
> > +       while ((readb(uart_base + REG_STATUS) & UART_TX_FULL))
> >                 ;
> >         writeb(ch, uart_base + REG_TX);
> >  }
> >
> >  static int shakti_uart_getc(void)
> >  {
> > -       u16 status = readw(uart_base + REG_STATUS);
> > -       if (status & UART_RX_FULL)
> > +       if (readb(uart_base + REG_STATUS) & UART_RX_NOT_EMPTY)
> >                 return readb(uart_base + REG_RX);
> >         return -1;
> >  }
> > --
> > 2.34.1
> >