On Mon, Aug 10, 2015 at 12:30:18AM -0300, Fabio Estevam wrote:
> Hi Eduardo,
>
> On Sun, Aug 9, 2015 at 3:19 PM, Eduardo Valentin <edubezval@xxxxxxxxx> wrote:
> > This change teaches the imx serial driver to save its
> > context and restore it across suspend and resume path.
> > To do so, it introduces serial_imx_restore_context()
> > and serial_imx_save_context() functions. They use
> > a shadow set of registers to save key registers
> > and restore them accordingly. These functions can
> > be reused on other situations, when the device
> > context is lost.
> >
> > Cc: Fabio Stevam <festevam@xxxxxxxxx>
>
> s/Stevam/Estevam (applies to all the patches)
Sorry, my bad here.
>
> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Cc: Jiri Slaby <jslaby@xxxxxxxx>
> > Cc: linux-serial@xxxxxxxxxxxxxxx
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > Signed-off-by: Eduardo Valentin <edubezval@xxxxxxxxx>
> > ---
> > drivers/tty/serial/imx.c | 34 ++++++++++++++++++++++++++++++++++
> > 1 file changed, 34 insertions(+)
> >
> > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> > index a03855d..494b182 100644
> > --- a/drivers/tty/serial/imx.c
> > +++ b/drivers/tty/serial/imx.c
> > @@ -217,6 +217,8 @@ struct imx_port {
> > unsigned int tx_bytes;
> > unsigned int dma_tx_nents;
> > wait_queue_head_t dma_wait;
> > + unsigned int saved_reg[8];
> > + bool context_saved;
> > };
> >
> > struct imx_port_ucrs {
> > @@ -1803,6 +1805,36 @@ static struct uart_driver imx_reg = {
> > .cons = IMX_CONSOLE,
> > };
> >
> > +static void serial_imx_restore_context(struct imx_port *sport)
> > +{
> > + if (!sport->context_saved)
> > + return;
> > +
> > + writel(sport->saved_reg[4], sport->port.membase + UFCR);
> > + writel(sport->saved_reg[5], sport->port.membase + UBIR);
> > + writel(sport->saved_reg[6], sport->port.membase + UBMR);
> > + writel(sport->saved_reg[7], sport->port.membase + IMX21_UTS);
> > + writel(sport->saved_reg[0], sport->port.membase + UCR1);
> > + writel(sport->saved_reg[1] | 0x1, sport->port.membase + UCR2);
> > + writel(sport->saved_reg[2], sport->port.membase + UCR3);
> > + writel(sport->saved_reg[3], sport->port.membase + UCR4);
> > + sport->context_saved = false;
> > +}
> > +
> > +static void serial_imx_save_context(struct imx_port *sport)
> > +{
> > + /* Save necessary regs */
> > + sport->saved_reg[0] = readl(sport->port.membase + UCR1);
> > + sport->saved_reg[1] = readl(sport->port.membase + UCR2);
> > + sport->saved_reg[2] = readl(sport->port.membase + UCR3);
> > + sport->saved_reg[3] = readl(sport->port.membase + UCR4);
> > + sport->saved_reg[4] = readl(sport->port.membase + UFCR);
> > + sport->saved_reg[5] = readl(sport->port.membase + UBIR);
> > + sport->saved_reg[6] = readl(sport->port.membase + UBMR);
> > + sport->saved_reg[7] = readl(sport->port.membase + IMX21_UTS);
> > + sport->context_saved = true;
> > +}
>
> This seems to be similar to what Shenwei posted earlier:
> http://lists.infradead.org/pipermail/linux-arm-kernel/2015-July/360841.html
OK. Do you know what is the status of that patch set?
did it get accepted by any tree so far?
>
> Regards,
>
> Fabio Estevam
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