Re: [PATCH V2 02/12] pinctrl: tegra: add suspend and resume support

From: Dmitry Osipenko <digetx@gmail.com>
To: Sowjanya Komatineni <skomatineni@nvidia.com>,
	thierry.reding@gmail.com, jonathanh@nvidia.com,
	tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com,
	linus.walleij@linaro.org, stefan@agner.ch, mark.rutland@arm.com
Cc: pdeschrijver@nvidia.com, pgaikwad@nvidia.com, sboyd@kernel.org,
	linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org,
	jckuo@nvidia.com, josephl@nvidia.com, talho@nvidia.com,
	linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
	mperttunen@nvidia.com, spatra@nvidia.com, robh+dt@kernel.org,
	devicetree@vger.kernel.org
Subject: Re: [PATCH V2 02/12] pinctrl: tegra: add suspend and resume support
Date: Wed, 29 May 2019 18:29:52 +0300	[thread overview]
Message-ID: <6273a790-d4b7-c501-3fec-d9816288b139@gmail.com> (raw)
In-Reply-To: <1559084936-4610-3-git-send-email-skomatineni@nvidia.com>

29.05.2019 2:08, Sowjanya Komatineni пишет:
> This patch adds suspend and resume support for Tegra pinctrl driver
> and registers them to syscore so the pinmux settings are restored
> before the devices resume.
> 
> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
> ---
>  drivers/pinctrl/tegra/pinctrl-tegra.c    | 68 +++++++++++++++++++++++++++++++-
>  drivers/pinctrl/tegra/pinctrl-tegra.h    |  3 ++
>  drivers/pinctrl/tegra/pinctrl-tegra114.c |  1 +
>  drivers/pinctrl/tegra/pinctrl-tegra124.c |  1 +
>  drivers/pinctrl/tegra/pinctrl-tegra20.c  |  1 +
>  drivers/pinctrl/tegra/pinctrl-tegra210.c |  1 +
>  drivers/pinctrl/tegra/pinctrl-tegra30.c  |  1 +
>  7 files changed, 75 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pinctrl/tegra/pinctrl-tegra.c b/drivers/pinctrl/tegra/pinctrl-tegra.c
> index a5008c066bac..bdc47e62c457 100644
> --- a/drivers/pinctrl/tegra/pinctrl-tegra.c
> +++ b/drivers/pinctrl/tegra/pinctrl-tegra.c
> @@ -28,11 +28,18 @@
>  #include <linux/pinctrl/pinmux.h>
>  #include <linux/pinctrl/pinconf.h>
>  #include <linux/slab.h>
> +#include <linux/syscore_ops.h>
>  
>  #include "../core.h"
>  #include "../pinctrl-utils.h"
>  #include "pinctrl-tegra.h"
>  
> +#define EMMC2_PAD_CFGPADCTRL_0			0x1c8
> +#define EMMC4_PAD_CFGPADCTRL_0			0x1e0
> +#define EMMC_DPD_PARKING			(0x1fff << 14)
> +
> +static struct tegra_pmx *pmx;
> +
>  static inline u32 pmx_readl(struct tegra_pmx *pmx, u32 bank, u32 reg)
>  {
>  	return readl(pmx->regs[bank] + reg);
> @@ -629,6 +636,50 @@ static void tegra_pinctrl_clear_parked_bits(struct tegra_pmx *pmx)
>  	}
>  }
>  
> +static int __maybe_unused tegra_pinctrl_suspend(void)
> +{
> +	u32 *backup_regs = pmx->backup_regs;
> +	u32 *regs;
> +	int i, j;
> +
> +	for (i = 0; i < pmx->nbanks; i++) {
> +		regs = pmx->regs[i];
> +		for (j = 0; j < pmx->reg_bank_size[i] / 4; j++)
> +			*backup_regs++ = readl(regs++);
> +	}
> +
> +	return pinctrl_force_sleep(pmx->pctl);
> +}
> +
> +static void __maybe_unused tegra_pinctrl_resume(void)
> +{
> +	u32 *backup_regs = pmx->backup_regs;
> +	u32 *regs;
> +	u32 val;
> +	int i, j;
> +
> +	for (i = 0; i < pmx->nbanks; i++) {
> +		regs = pmx->regs[i];
> +		for (j = 0; j < pmx->reg_bank_size[i] / 4; j++)
> +			writel(*backup_regs++, regs++);
> +	}
> +
> +	if (pmx->soc->has_park_padcfg) {
> +		val = pmx_readl(pmx, 0, EMMC2_PAD_CFGPADCTRL_0);
> +		val &= ~EMMC_DPD_PARKING;
> +		pmx_writel(pmx, val, 0, EMMC2_PAD_CFGPADCTRL_0);
> +
> +		val = pmx_readl(pmx, 0, EMMC4_PAD_CFGPADCTRL_0);
> +		val &= ~EMMC_DPD_PARKING;
> +		pmx_writel(pmx, val, 0, EMMC4_PAD_CFGPADCTRL_0);
> +	}
> +}
>

But the CFGPADCTRL registers are already programmed by restoring the
backup_regs and hence the relevant EMMC's are already unparked. Hence
why do you need to force-unpark both of the EMMC's? What if EMMC is
unpopulated on a board, why do you need to unpark it then?

-- 
Dmitry