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

From: "Théo Lebrun" <theo.lebrun@bootlin.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Roger Quadros <rogerq@kernel.org>,
	Peter Chen <peter.chen@kernel.org>,
	Pawel Laszczak <pawell@cadence.com>, Nishanth Menon <nm@ti.com>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Tero Kristo <kristo@kernel.org>
Cc: linux-usb@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	"Thomas Petazzoni thomas.petazzoni"@bootlin.com,
	"Grégory Clement" <gregory.clement@bootlin.com>,
	"Théo Lebrun" <theo.lebrun@bootlin.com>
Subject: [PATCH v2 4/7] usb: cdns3-ti: add suspend/resume procedures for J7200
Date: Mon, 20 Nov 2023 18:06:04 +0100	[thread overview]
Message-ID: <20231120-j7200-usb-suspend-v2-4-038c7e4a3df4@bootlin.com> (raw)
In-Reply-To: <20231120-j7200-usb-suspend-v2-0-038c7e4a3df4@bootlin.com>

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");
 
 	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),
 	},
 };
 

-- 
2.42.0

