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Message-ID: <ea3b5be735f51dd7c9ac7e77a19596b0e4ced740.camel@pengutronix.de>
Subject: Re: [PATCH] pinctrl: microchip sgpio: use reset driver
From:   Philipp Zabel <p.zabel@pengutronix.de>
To:     Horatiu Vultur <horatiu.vultur@microchip.com>,
        lars.povlsen@microchip.com, Steen.Hegelund@microchip.com,
        UNGLinuxDriver@microchip.com, linus.walleij@linaro.org,
        linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org,
        linux-kernel@vger.kernel.org
Date:   Tue, 12 Oct 2021 15:40:42 +0200
In-Reply-To: <20211012122435.2081930-1-horatiu.vultur@microchip.com>
References: <20211012122435.2081930-1-horatiu.vultur@microchip.com>
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On Tue, 2021-10-12 at 14:24 +0200, Horatiu Vultur wrote:
> On lan966x platform when the switch gets reseted then also the sgpio
> gets reseted. The fix for this is to extend also the sgpio driver to
> call the reset driver which will be reseted only once by the first
> driver that is probed.
> 
> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> ---
>  drivers/pinctrl/pinctrl-microchip-sgpio.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/pinctrl/pinctrl-microchip-sgpio.c b/drivers/pinctrl/pinctrl-microchip-sgpio.c
> index 072bccdea2a5..e8a91d0824cb 100644
> --- a/drivers/pinctrl/pinctrl-microchip-sgpio.c
> +++ b/drivers/pinctrl/pinctrl-microchip-sgpio.c
> @@ -17,6 +17,7 @@
>  #include <linux/pinctrl/pinmux.h>
>  #include <linux/platform_device.h>
>  #include <linux/property.h>
> +#include <linux/reset.h>
>  
>  #include "core.h"
>  #include "pinconf.h"
> @@ -803,6 +804,7 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
>  	int div_clock = 0, ret, port, i, nbanks;
>  	struct device *dev = &pdev->dev;
>  	struct fwnode_handle *fwnode;
> +	struct reset_control *reset;
>  	struct sgpio_priv *priv;
>  	struct clk *clk;
>  	u32 val;
> @@ -813,6 +815,10 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
>  
>  	priv->dev = dev;
>  
> +	reset = devm_reset_control_get_shared(&pdev->dev, "switch");

This seems to be missing an update to the devicetree binding.

Just to make sure we aren't introducing a circular dependency here, are
the PHY reset GPIOs that are toggled by the "switch" reset controller in
[1] provided by one of the sgpio controllers?

[1] https://lore.kernel.org/all/20211012114238.2060101-3-horatiu.vultur@microchip.com/

regards
Philipp