Re: [PATCH 07/11] soc: imx: gpcv2: add support for optional resets

From: Rob Herring <robh@kernel.org>
To: Lucas Stach <l.stach@pengutronix.de>
Cc: Marek Vasut <marex@denx.de>,
	devicetree@vger.kernel.org, Shawn Guo <shawnguo@kernel.org>,
	Frieder Schrempf <frieder.schrempf@kontron.de>,
	patchwork-lst@pengutronix.de, NXP Linux Team <linux-imx@nxp.com>,
	kernel@pengutronix.de, Fabio Estevam <festevam@gmail.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 07/11] soc: imx: gpcv2: add support for optional resets
Date: Tue, 6 Oct 2020 14:42:14 -0500	[thread overview]
Message-ID: <20201006194214.GA2702908@bogus> (raw)
In-Reply-To: <20200930155006.535712-8-l.stach@pengutronix.de>

On Wed, Sep 30, 2020 at 05:50:02PM +0200, Lucas Stach wrote:
> Normally the reset for the devices inside the power domain is
> triggered automatically from the PGC in the power-up sequencing,
> however on i.MX8MM this doesn't work for the GPU power domains.
> 
> Add support for triggering the reset explicitly during the power
> up sequencing.
> 
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
>  .../devicetree/bindings/power/fsl,imx-gpcv2.yaml    |  6 ++++++
>  drivers/soc/imx/gpcv2.c                             | 13 +++++++++++++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/power/fsl,imx-gpcv2.yaml b/Documentation/devicetree/bindings/power/fsl,imx-gpcv2.yaml
> index bde09a0b2da3..9773771b9000 100644
> --- a/Documentation/devicetree/bindings/power/fsl,imx-gpcv2.yaml
> +++ b/Documentation/devicetree/bindings/power/fsl,imx-gpcv2.yaml
> @@ -62,6 +62,12 @@ properties:
>  
>            power-supply: true
>  
> +          resets:
> +            description: |
> +              A number of phandles to resets that need to be asserted during
> +              power-up sequencing of the domain.
> +            minItems: 1

What's the max? It's going to default to 1 if you don't say.

> +
>          required:
>            - '#power-domain-cells'
>            - reg
> diff --git a/drivers/soc/imx/gpcv2.c b/drivers/soc/imx/gpcv2.c
> index db93fef0c76b..76aa8a67d8a7 100644
> --- a/drivers/soc/imx/gpcv2.c
> +++ b/drivers/soc/imx/gpcv2.c
> @@ -15,6 +15,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/regmap.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/reset.h>
>  #include <linux/sizes.h>
>  #include <dt-bindings/power/imx7-power.h>
>  #include <dt-bindings/power/imx8mq-power.h>
> @@ -112,6 +113,7 @@ struct imx_pgc_domain {
>  	struct regulator *regulator;
>  	struct clk *clk[GPC_CLK_MAX];
>  	int num_clks;
> +	struct reset_control *reset;
>  
>  	unsigned int pgc;
>  
> @@ -167,6 +169,8 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd)
>  		}
>  	}
>  
> +	reset_control_assert(domain->reset);
> +
>  	if (domain->bits.pxx) {
>  		/* request the domain to power up */
>  		regmap_update_bits(domain->regmap, GPC_PU_PGC_SW_PUP_REQ,
> @@ -189,6 +193,8 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd)
>  				   GPC_PGC_CTRL_PCR, 0);
>  	}
>  
> +	reset_control_deassert(domain->reset);
> +
>  	/* request the ADB400 to power up */
>  	if (domain->bits.hskreq) {
>  		regmap_update_bits(domain->regmap, GPC_PU_PWRHSK,
> @@ -577,6 +583,13 @@ static int imx_pgc_domain_probe(struct platform_device *pdev)
>  				      domain->voltage, domain->voltage);
>  	}
>  
> +	domain->reset = devm_reset_control_array_get_optional_exclusive(domain->dev);
> +	if (IS_ERR(domain->reset)) {
> +		if (PTR_ERR(domain->reset) != -EPROBE_DEFER)
> +			dev_err(domain->dev, "Failed to get domain's reset\n");
> +		return PTR_ERR(domain->reset);
> +	}
> +
>  	ret = imx_pgc_get_clocks(domain);
>  	if (ret) {
>  		if (ret != -EPROBE_DEFER)
> -- 
> 2.20.1
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel