Re: [PATCHv2] gpio: omap: Save and restore sysconfig

[Bartosz Golaszewski <brgl@bgdev.pl>]

On Sat, Apr 17, 2021 at 10:38 AM Tony Lindgren <tony@atomide.com> wrote:
>
> As we are using cpu_pm to save and restore context, we must also save and
> restore the GPIO sysconfig register. This is needed because we are not
> calling PM runtime functions at all with cpu_pm.
>
> We need to save the sysconfig on idle as it's value can get reconfigured by
> PM runtime and can be different from the init time value. Device specific
> flags like "ti,no-idle-on-init" can affect the init value.
>
> Fixes: b764a5863fd8 ("gpio: omap: Remove custom PM calls and use cpu_pm instead")
> Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
> Cc: Adam Ford <aford173@gmail.com>
> Cc: Andreas Kemnade <andreas@kemnade.info>
> Cc: Grygorii Strashko <grygorii.strashko@ti.com>
> Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
>  drivers/gpio/gpio-omap.c                | 9 +++++++++
>  include/linux/platform_data/gpio-omap.h | 3 +++
>  2 files changed, 12 insertions(+)
>
> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> --- a/drivers/gpio/gpio-omap.c
> +++ b/drivers/gpio/gpio-omap.c
> @@ -29,6 +29,7 @@
>  #define OMAP4_GPIO_DEBOUNCINGTIME_MASK 0xFF
>
>  struct gpio_regs {
> +       u32 sysconfig;
>         u32 irqenable1;
>         u32 irqenable2;
>         u32 wake_en;
> @@ -1069,6 +1070,7 @@ static void omap_gpio_init_context(struct gpio_bank *p)
>         const struct omap_gpio_reg_offs *regs = p->regs;
>         void __iomem *base = p->base;
>
> +       p->context.sysconfig    = readl_relaxed(base + regs->sysconfig);
>         p->context.ctrl         = readl_relaxed(base + regs->ctrl);
>         p->context.oe           = readl_relaxed(base + regs->direction);
>         p->context.wake_en      = readl_relaxed(base + regs->wkup_en);
> @@ -1088,6 +1090,7 @@ static void omap_gpio_restore_context(struct gpio_bank *bank)
>         const struct omap_gpio_reg_offs *regs = bank->regs;
>         void __iomem *base = bank->base;
>
> +       writel_relaxed(bank->context.sysconfig, base + regs->sysconfig);
>         writel_relaxed(bank->context.wake_en, base + regs->wkup_en);
>         writel_relaxed(bank->context.ctrl, base + regs->ctrl);
>         writel_relaxed(bank->context.leveldetect0, base + regs->leveldetect0);
> @@ -1115,6 +1118,10 @@ static void omap_gpio_idle(struct gpio_bank *bank, bool may_lose_context)
>
>         bank->saved_datain = readl_relaxed(base + bank->regs->datain);
>
> +       /* Save syconfig, it's runtime value can be different from init value */
> +       if (bank->loses_context)
> +               bank->context.sysconfig = readl_relaxed(base + bank->regs->sysconfig);
> +
>         if (!bank->enabled_non_wakeup_gpios)
>                 goto update_gpio_context_count;
>
> @@ -1279,6 +1286,7 @@ static int gpio_omap_cpu_notifier(struct notifier_block *nb,
>
>  static const struct omap_gpio_reg_offs omap2_gpio_regs = {
>         .revision =             OMAP24XX_GPIO_REVISION,
> +       .sysconfig =            OMAP24XX_GPIO_SYSCONFIG,
>         .direction =            OMAP24XX_GPIO_OE,
>         .datain =               OMAP24XX_GPIO_DATAIN,
>         .dataout =              OMAP24XX_GPIO_DATAOUT,
> @@ -1302,6 +1310,7 @@ static const struct omap_gpio_reg_offs omap2_gpio_regs = {
>
>  static const struct omap_gpio_reg_offs omap4_gpio_regs = {
>         .revision =             OMAP4_GPIO_REVISION,
> +       .sysconfig =            OMAP4_GPIO_SYSCONFIG,
>         .direction =            OMAP4_GPIO_OE,
>         .datain =               OMAP4_GPIO_DATAIN,
>         .dataout =              OMAP4_GPIO_DATAOUT,
> diff --git a/include/linux/platform_data/gpio-omap.h b/include/linux/platform_data/gpio-omap.h
> --- a/include/linux/platform_data/gpio-omap.h
> +++ b/include/linux/platform_data/gpio-omap.h
> @@ -85,6 +85,7 @@
>   * omap2+ specific GPIO registers
>   */
>  #define OMAP24XX_GPIO_REVISION         0x0000
> +#define OMAP24XX_GPIO_SYSCONFIG                0x0010
>  #define OMAP24XX_GPIO_IRQSTATUS1       0x0018
>  #define OMAP24XX_GPIO_IRQSTATUS2       0x0028
>  #define OMAP24XX_GPIO_IRQENABLE2       0x002c
> @@ -108,6 +109,7 @@
>  #define OMAP24XX_GPIO_SETDATAOUT       0x0094
>
>  #define OMAP4_GPIO_REVISION            0x0000
> +#define OMAP4_GPIO_SYSCONFIG           0x0010
>  #define OMAP4_GPIO_EOI                 0x0020
>  #define OMAP4_GPIO_IRQSTATUSRAW0       0x0024
>  #define OMAP4_GPIO_IRQSTATUSRAW1       0x0028
> @@ -148,6 +150,7 @@
>  #ifndef __ASSEMBLER__
>  struct omap_gpio_reg_offs {
>         u16 revision;
> +       u16 sysconfig;
>         u16 direction;
>         u16 datain;
>         u16 dataout;
> --
> 2.31.1

Applied for fixes, thanks!

Bartosz