linux-kernel - Re: [PATCH 9/9] remoteproc/wkup_m3: Use reset control driver if available

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Message-ID: <c8ea80c2eb79f80539911f3563398957beedaa41.camel@pengutronix.de>
Date:   Mon, 26 Oct 2020 12:35:21 +0100
From:   Philipp Zabel <p.zabel@...gutronix.de>
To:     Tony Lindgren <tony@...mide.com>, linux-omap@...r.kernel.org
Cc:     "Andrew F . Davis" <afd@...com>, Dave Gerlach <d-gerlach@...com>,
        Faiz Abbas <faiz_abbas@...com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Grygorii Strashko <grygorii.strashko@...com>,
        Keerthy <j-keerthy@...com>, Nishanth Menon <nm@...com>,
        Peter Ujfalusi <peter.ujfalusi@...com>,
        Roger Quadros <rogerq@...com>, Suman Anna <s-anna@...com>,
        Tero Kristo <t-kristo@...com>, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-remoteproc@...r.kernel.org,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Michael Turquette <mturquette@...libre.com>,
        Santosh Shilimkar <ssantosh@...nel.org>,
        Stephen Boyd <sboyd@...nel.org>, linux-clk@...r.kernel.org
Subject: Re: [PATCH 9/9] remoteproc/wkup_m3: Use reset control driver if
 available

Hi Tony,

On Mon, 2020-10-26 at 13:10 +0200, Tony Lindgren wrote:
> In order to move wkup_m3 to probe without platform data, let's add
> support for using optional reset control driver if configured in the
> dts. With this change and the related dts change, we can start
> dropping the platform data for am335x.
> 
> And once wkup_m3 no longer needs platform data, we can simply drop the
> related legacy reset platform data callbacks from wkup_m3 driver later
> on after also am437x no longer depends on it.
> 
> Cc: linux-remoteproc@...r.kernel.org
> Cc: Bjorn Andersson <bjorn.andersson@...aro.org>
> Cc: Dave Gerlach <d-gerlach@...com>
> Cc: Philipp Zabel <p.zabel@...gutronix.de>
> Cc: Suman Anna <s-anna@...com>
> Signed-off-by: Tony Lindgren <tony@...mide.com>
> ---
> 
> Please review and ack if no issues. If you guys instead want to set up an
> immutable remoteproc branch with just this patch in it against v5.10-rc1
> that works too :)
> 
> ---
>  drivers/remoteproc/wkup_m3_rproc.c | 28 +++++++++++++++++++++-------
>  1 file changed, 21 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/remoteproc/wkup_m3_rproc.c b/drivers/remoteproc/wkup_m3_rproc.c
> --- a/drivers/remoteproc/wkup_m3_rproc.c
> +++ b/drivers/remoteproc/wkup_m3_rproc.c
> @@ -17,6 +17,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/remoteproc.h>
> +#include <linux/reset.h>
>  
>  #include <linux/platform_data/wkup_m3.h>
>  
> @@ -43,11 +44,13 @@ struct wkup_m3_mem {
>   * @rproc: rproc handle
>   * @pdev: pointer to platform device
>   * @mem: WkupM3 memory information
> + * @rsts: reset control
>   */
>  struct wkup_m3_rproc {
>  	struct rproc *rproc;
>  	struct platform_device *pdev;
>  	struct wkup_m3_mem mem[WKUPM3_MEM_MAX];
> +	struct reset_control *rsts;
>  };
>  
>  static int wkup_m3_rproc_start(struct rproc *rproc)
> @@ -57,6 +60,9 @@ static int wkup_m3_rproc_start(struct rproc *rproc)
>  	struct device *dev = &pdev->dev;
>  	struct wkup_m3_platform_data *pdata = dev_get_platdata(dev);
>  
> +	if (wkupm3->rsts)

No need for this check, reset_control_deassert() just returns 0 if the
rstc parameter is NULL.

> +		return reset_control_deassert(wkupm3->rsts);
> +
>  	if (pdata->deassert_reset(pdev, pdata->reset_name)) {
>  		dev_err(dev, "Unable to reset wkup_m3!\n");
>  		return -ENODEV;
> @@ -72,6 +78,9 @@ static int wkup_m3_rproc_stop(struct rproc *rproc)
>  	struct device *dev = &pdev->dev;
>  	struct wkup_m3_platform_data *pdata = dev_get_platdata(dev);
>  
> +	if (wkupm3->rsts)

Same as above.

> +		return reset_control_assert(wkupm3->rsts);
> +
>  	if (pdata->assert_reset(pdev, pdata->reset_name)) {
>  		dev_err(dev, "Unable to assert reset of wkup_m3!\n");
>  		return -ENODEV;
> @@ -132,12 +141,6 @@ static int wkup_m3_rproc_probe(struct platform_device *pdev)
>  	int ret;
>  	int i;
>  
> -	if (!(pdata && pdata->deassert_reset && pdata->assert_reset &&
> -	      pdata->reset_name)) {
> -		dev_err(dev, "Platform data missing!\n");
> -		return -ENODEV;
> -	}
> -
>  	ret = of_property_read_string(dev->of_node, "ti,pm-firmware",
>  				      &fw_name);
>  	if (ret) {
> @@ -165,6 +168,17 @@ static int wkup_m3_rproc_probe(struct platform_device *pdev)
>  	wkupm3->rproc = rproc;
>  	wkupm3->pdev = pdev;
>  
> +	wkupm3->rsts = devm_reset_control_get_optional_shared(dev, "rstctrl");
> +	if (PTR_ERR_OR_ZERO(wkupm3->rsts)) {

Please properly return errors. rsts will be NULL if the optional rstctrl
reset is not specified:

	if (IS_ERR(wkump3->rsts))
		return PTR_ERR(wkump3->rsts);

	if (!wkump3->rsts) {
> +		if (!(pdata && pdata->deassert_reset && pdata->assert_reset &&
> +		      pdata->reset_name)) {
> +			dev_err(dev, "Platform data missing!\n");
> +			ret = -ENODEV;
> +			goto err_put_rproc;
> +		}
> +		wkupm3->rsts = NULL;

I assume this will later be dropped with the platform data support?

> +	}
> +
>  	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
>  		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>  						   mem_names[i]);
> @@ -173,7 +187,7 @@ static int wkup_m3_rproc_probe(struct platform_device *pdev)
>  			dev_err(&pdev->dev, "devm_ioremap_resource failed for resource %d\n",
>  				i);
>  			ret = PTR_ERR(wkupm3->mem[i].cpu_addr);
> -			goto err;
> +			goto err_put_rproc;
>  		}
>  		wkupm3->mem[i].bus_addr = res->start;
>  		wkupm3->mem[i].size = resource_size(res);

regards
Philipp