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Message-ID: <a73a43a71adedcdc34d060bcff10fc13ca1d6d16.camel@pengutronix.de>
Subject: Re: [PATCH v4 2/2] pinctrl: microchip sgpio: use reset driver
From:   Philipp Zabel <p.zabel@pengutronix.de>
To:     Horatiu Vultur <horatiu.vultur@microchip.com>,
        linus.walleij@linaro.org, robh+dt@kernel.org,
        lars.povlsen@microchip.com, Steen.Hegelund@microchip.com,
        UNGLinuxDriver@microchip.com, linux-gpio@vger.kernel.org,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Date:   Fri, 15 Oct 2021 15:38:59 +0200
In-Reply-To: <20211015132526.200816-3-horatiu.vultur@microchip.com>
References: <20211015132526.200816-1-horatiu.vultur@microchip.com>
         <20211015132526.200816-3-horatiu.vultur@microchip.com>
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On Fri, 2021-10-15 at 15:25 +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 | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/pinctrl/pinctrl-microchip-sgpio.c b/drivers/pinctrl/pinctrl-microchip-sgpio.c
> index 072bccdea2a5..23f5a744edc4 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 +815,9 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
>  
>  	priv->dev = dev;
>  
> +	reset = devm_reset_control_get_optional_shared(&pdev->dev, NULL);

	if (IS_ERR(reset))
		return dev_err_probe(dev, PTR_ERR(reset), "Failed to get reset\n");

This could still happen if the device tree is broken or on
-EPROBE_DEFER.

> +	reset_control_reset(reset);
> +
>  	clk = devm_clk_get(dev, NULL);
>  	if (IS_ERR(clk))
>  		return dev_err_probe(dev, PTR_ERR(clk), "Failed to get clock\n");

regards
Philipp