diff mbox series

[v2,4/7] usb: cdns3-ti: add suspend/resume procedures for J7200

Message ID 20231120-j7200-usb-suspend-v2-4-038c7e4a3df4@bootlin.com
State New
Headers
Series usb: cdns: fix suspend on J7200 by assuming reset-on-resume |

Commit Message

Théo Lebrun Nov. 20, 2023, 5:06 p.m. UTC 
  Hardware initialisation is only done at probe. The J7200 USB controller
is reset at resume because of power-domains toggling off & on. We
therefore reconfigure the hardware at resume.

Reuse the newly extracted cdns_ti_init_hw() function that contains the
register write sequence.

Only focus J7200 as other SoC are untested. If the controller does not
reset we do not want to redo reg writes.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
 drivers/usb/cdns3/cdns3-ti.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

Comments

Krzysztof Kozlowski Nov. 20, 2023, 5:31 p.m. UTC | #1 
On 20/11/2023 18:06, Théo Lebrun wrote:
> Hardware initialisation is only done at probe. The J7200 USB controller
> is reset at resume because of power-domains toggling off & on. We
> therefore reconfigure the hardware at resume.
> 
> Reuse the newly extracted cdns_ti_init_hw() function that contains the
> register write sequence.
> 
> Only focus J7200 as other SoC are untested. If the controller does not
> reset we do not want to redo reg writes.
> 
> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
> ---
>  drivers/usb/cdns3/cdns3-ti.c | 24 +++++++++++++++++++++++-
>  1 file changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/cdns3/cdns3-ti.c b/drivers/usb/cdns3/cdns3-ti.c
> index d4232b440e4e..84f93c2fcd5c 100644
> --- a/drivers/usb/cdns3/cdns3-ti.c
> +++ b/drivers/usb/cdns3/cdns3-ti.c
> @@ -58,6 +58,7 @@ struct cdns_ti {
>  	struct clk *usb2_refclk;
>  	struct clk *lpm_clk;
>  	int usb2_refclk_rate_code;
> +	bool reset_on_resume;
>  };
>  
>  static const int cdns_ti_rate_table[] = {	/* in KHZ */
> @@ -172,6 +173,7 @@ static int cdns_ti_probe(struct platform_device *pdev)
>  	data->usb2_refclk_rate_code = i;
>  	data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
>  	data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
> +	data->reset_on_resume = of_device_is_compatible(node, "ti,j7200-usb");

No, use driver data for this. Don't put compatibles in the code. It
makes it unmanageable soon.

I am repeating this issue from time to time :/

Best regards,
Krzysztof
Théo Lebrun Nov. 21, 2023, 4:48 p.m. UTC | #2 
Hello Krzysztof,

On Mon Nov 20, 2023 at 6:31 PM CET, Krzysztof Kozlowski wrote:
> On 20/11/2023 18:06, Théo Lebrun wrote:

[...]

> > --- a/drivers/usb/cdns3/cdns3-ti.c
> > +++ b/drivers/usb/cdns3/cdns3-ti.c
> >  static const int cdns_ti_rate_table[] = {	/* in KHZ */
> > @@ -172,6 +173,7 @@ static int cdns_ti_probe(struct platform_device *pdev)
> >  	data->usb2_refclk_rate_code = i;
> >  	data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
> >  	data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
> > +	data->reset_on_resume = of_device_is_compatible(node, "ti,j7200-usb");
>
> No, use driver data for this. Don't put compatibles in the code. It
> makes it unmanageable soon.

Fixed for next revision. I hesitated on this patch but I'll know for
next time.

Thanks,

--
Théo Lebrun, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
diff mbox series

Patch

diff --git a/drivers/usb/cdns3/cdns3-ti.c b/drivers/usb/cdns3/cdns3-ti.c
index d4232b440e4e..84f93c2fcd5c 100644
--- a/drivers/usb/cdns3/cdns3-ti.c
+++ b/drivers/usb/cdns3/cdns3-ti.c
@@ -58,6 +58,7 @@  struct cdns_ti {
 	struct clk *usb2_refclk;
 	struct clk *lpm_clk;
 	int usb2_refclk_rate_code;
+	bool reset_on_resume;
 };
 
 static const int cdns_ti_rate_table[] = {	/* in KHZ */
@@ -172,6 +173,7 @@  static int cdns_ti_probe(struct platform_device *pdev)
 	data->usb2_refclk_rate_code = i;
 	data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
 	data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
+	data->reset_on_resume = of_device_is_compatible(node, "ti,j7200-usb");
 
 	cdns_ti_init_hw(data);
 
@@ -202,7 +204,26 @@  static void cdns_ti_remove(struct platform_device *pdev)
 	platform_set_drvdata(pdev, NULL);
 }
 
+#ifdef CONFIG_PM
+
+static int cdns_ti_resume(struct device *dev)
+{
+	struct cdns_ti *data = dev_get_drvdata(dev);
+
+	if (data->reset_on_resume)
+		cdns_ti_init_hw(data);
+
+	return 0;
+}
+
+static const struct dev_pm_ops cdns_ti_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(NULL, cdns_ti_resume)
+};
+
+#endif /* CONFIG_PM */
+
 static const struct of_device_id cdns_ti_of_match[] = {
+	{ .compatible = "ti,j7200-usb", },
 	{ .compatible = "ti,j721e-usb", },
 	{ .compatible = "ti,am64-usb", },
 	{},
@@ -213,8 +234,9 @@  static struct platform_driver cdns_ti_driver = {
 	.probe		= cdns_ti_probe,
 	.remove_new	= cdns_ti_remove,
 	.driver		= {
-		.name	= "cdns3-ti",
+		.name		= "cdns3-ti",
 		.of_match_table	= cdns_ti_of_match,
+		.pm		= pm_ptr(&cdns_ti_pm_ops),
 	},
 };