"Govindraj.R" <govindraj.raja@ti.com> writes:

> Adapts omap-serial driver to use pm_runtime api's.
>
> 1.) Populate reg values to uart port which can be used for context restore.
> 2.) Moving context_restore func to driver from serial.c
> 3.) Adding port_enable/disable func to enable/disable given uart port.
>     enable port using get_sync and disable using autosuspend.
> 4.) using runtime irq safe api to make get_sync be called from irq context.
>
> Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
> ---
>  arch/arm/mach-omap2/serial.c                  |   16 ++
>  arch/arm/plat-omap/include/plat/omap-serial.h |    2 +
>  drivers/tty/serial/omap-serial.c              |  211 ++++++++++++++++++++++---
>  3 files changed, 203 insertions(+), 26 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
> index 8c1a4c7..314d82f 100644
> --- a/arch/arm/mach-omap2/serial.c
> +++ b/arch/arm/mach-omap2/serial.c
> @@ -189,6 +189,21 @@ static void omap_serial_fill_default_pads(struct omap_board_data *bdata)
>       }
>  }
>
> +static void omap_uart_wakeup_enable(struct platform_device *pdev, bool enable)
> +{
> +     struct omap_uart_port_info *up = pdev->dev.platform_data;
> +
> +     /* Set or clear wake-enable bit */
> +     if (up->wk_en && up->wk_mask) {
> +             u32 v = __raw_readl(up->wk_en);
> +             if (enable)
> +                     v |= up->wk_mask;
> +             else
> +                     v &= ~up->wk_mask;
> +             __raw_writel(v, up->wk_en);
> +     }
> +}

Rather than having the driver do this via the PRCM, can you do an
experiment?  Can you try to leave the module-level wakeup enabled all
the time in the PRCM, and the driver can then enable/disable
module-level wakeups simply by toggling ENAWAKEUP in the module's
SYSCONFIG?  If that works, than you can just use
omap_hwmod_enable_wakeup() for this and not need the above function.

>  static void omap_uart_idle_init(struct omap_uart_port_info *uart,
>                               unsigned short num)
>  {
> @@ -332,6 +347,7 @@ void __init omap_serial_init_port(struct omap_board_data *bdata)
>
>       pdata->uartclk = OMAP24XX_BASE_BAUD * 16;
>       pdata->flags = UPF_BOOT_AUTOCONF;
> +     pdata->enable_wakeup = omap_uart_wakeup_enable;
>       if (bdata->id == omap_uart_con_id)
>               pdata->console_uart = true;
>

> +     pm_runtime_use_autosuspend(&pdev->dev);
> +     pm_runtime_set_autosuspend_delay(&pdev->dev,
> +                     OMAP_UART_AUTOSUSPEND_DELAY);
> +
> +     pm_runtime_enable(&pdev->dev);
> +     pm_runtime_irq_safe(&pdev->dev);
> +
> +     if (omap_up_info->console_uart) {
> +             od = to_omap_device(up->pdev);
> +             omap_hwmod_idle(od->hwmods[0]);

Driver should have know knowlege of the underlying hwmod.

I assume this is here because of the usage of HWMOD_INIT_NO_IDLE and
HWMOD_INIT_NO_RESET, right?

 With proper runtime PM, we should be able to
remove the need for using those flags.

Kevin

> +             serial_omap_port_enable(up);
> +             serial_omap_port_disable(up);
> +     }
> +
>       ui[pdev->id] = up;
>       serial_omap_add_console_port(up);
>
>       ret = uart_add_one_port(&serial_omap_reg, &up->port);
>       if (ret != 0)
> -             goto do_release_region;
> +             goto err1;
>
> +     dev_set_drvdata(&pdev->dev, up);
>       platform_set_drvdata(pdev, up);
> +
>       return 0;
>  err:
>       dev_err(&pdev->dev, "[UART%d]: failure [%s]: %d\n",
>                               pdev->id, __func__, ret);
> +err1:
> +     kfree(up);
>  do_release_region:
>       release_mem_region(mem->start, (mem->end - mem->start) + 1);
>       return ret;
> @@ -1318,20 +1421,76 @@ static int serial_omap_remove(struct platform_device *dev)
>
>       platform_set_drvdata(dev, NULL);
>       if (up) {
> +             pm_runtime_disable(&up->pdev->dev);
>               uart_remove_one_port(&serial_omap_reg, &up->port);
>               kfree(up);
>       }
>       return 0;
>  }
>
> +static void omap_uart_restore_context(struct uart_omap_port *up)
> +{
> +     u16 efr = 0;
> +
> +     serial_out(up, UART_OMAP_MDR1, up->mdr1);
> +     serial_out(up, UART_LCR, 0xBF); /* Config B mode */
> +     efr = serial_in(up, UART_EFR);
> +     serial_out(up, UART_EFR, UART_EFR_ECB);
> +     serial_out(up, UART_LCR, 0x0); /* Operational mode */
> +     serial_out(up, UART_IER, 0x0);
> +     serial_out(up, UART_LCR, 0xBF); /* Config B mode */
> +     serial_out(up, UART_DLL, up->dll);
> +     serial_out(up, UART_DLM, up->dlh);
> +     serial_out(up, UART_LCR, 0x0); /* Operational mode */
> +     serial_out(up, UART_IER, up->ier);
> +     serial_out(up, UART_FCR, up->fcr);
> +     serial_out(up, UART_LCR, 0x80);
> +     serial_out(up, UART_MCR, up->mcr);
> +     serial_out(up, UART_LCR, 0xBF); /* Config B mode */
> +     serial_out(up, UART_EFR, efr);
> +     serial_out(up, UART_LCR, UART_LCR_WLEN8);
> +     /* UART 16x mode */
> +     serial_out(up, UART_OMAP_MDR1, up->mdr1);
> +}
> +
> +static int omap_serial_runtime_suspend(struct device *dev)
> +{
> +     struct uart_omap_port *up = dev_get_drvdata(dev);
> +
> +     if (!up)
> +             goto done;
> +
> +     if (device_may_wakeup(dev))
> +             up->enable_wakeup(up->pdev, true);
> +     else
> +             up->enable_wakeup(up->pdev, false);
> +done:
> +     return 0;
> +}
> +
> +static int omap_serial_runtime_resume(struct device *dev)
> +{
> +     struct uart_omap_port *up = dev_get_drvdata(dev);
> +
> +     if (up)
> +             omap_uart_restore_context(up);
> +
> +     return 0;
> +}
> +
> +static const struct dev_pm_ops omap_serial_dev_pm_ops = {
> +     .suspend = serial_omap_suspend,
> +     .resume = serial_omap_resume,
> +     .runtime_suspend = omap_serial_runtime_suspend,
> +     .runtime_resume = omap_serial_runtime_resume,
> +};
> +
>  static struct platform_driver serial_omap_driver = {
>       .probe          = serial_omap_probe,
>       .remove         = serial_omap_remove,
> -
> -     .suspend        = serial_omap_suspend,
> -     .resume         = serial_omap_resume,
>       .driver         = {
>               .name   = DRIVER_NAME,
> +             .pm = &omap_serial_dev_pm_ops,
>       },
>  };