[PATCH v3 4/8] usb: cdns3-ti: support reset-on-resume behavior

From: Théo Lebrun
Date: Fri Feb 23 2024 - 11:06:35 EST


Add match data support, with one boolean to indicate whether the
hardware resets after a system-wide suspend. If hardware resets, we
force execute ->runtime_resume() at system-wide resume to run the
hardware init sequence.

No compatible exploits this functionality, just yet.

Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
---
drivers/usb/cdns3/cdns3-ti.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/drivers/usb/cdns3/cdns3-ti.c b/drivers/usb/cdns3/cdns3-ti.c
index 4c8a557e6a6f..f76327566798 100644
--- a/drivers/usb/cdns3/cdns3-ti.c
+++ b/drivers/usb/cdns3/cdns3-ti.c
@@ -57,9 +57,14 @@ struct cdns_ti {
unsigned vbus_divider:1;
struct clk *usb2_refclk;
struct clk *lpm_clk;
+ const struct cdns_ti_match_data *match_data;
int usb2_refclk_rate_code;
};

+struct cdns_ti_match_data {
+ bool reset_on_resume;
+};
+
static const int cdns_ti_rate_table[] = { /* in KHZ */
9600,
10000,
@@ -101,6 +106,7 @@ static int cdns_ti_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, data);

data->dev = dev;
+ data->match_data = device_get_match_data(dev);

data->usbss = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(data->usbss)) {
@@ -220,8 +226,29 @@ static int cdns_ti_runtime_resume(struct device *dev)
return 0;
}

+static int cdns_ti_suspend(struct device *dev)
+{
+ struct cdns_ti *data = dev_get_drvdata(dev);
+
+ if (data->match_data && data->match_data->reset_on_resume)
+ return pm_runtime_force_suspend(dev);
+ else
+ return 0;
+}
+
+static int cdns_ti_resume(struct device *dev)
+{
+ struct cdns_ti *data = dev_get_drvdata(dev);
+
+ if (data->match_data && data->match_data->reset_on_resume)
+ return pm_runtime_force_resume(dev);
+ else
+ return 0;
+}
+
static const struct dev_pm_ops cdns_ti_pm_ops = {
RUNTIME_PM_OPS(NULL, cdns_ti_runtime_resume, NULL)
+ SYSTEM_SLEEP_PM_OPS(cdns_ti_suspend, cdns_ti_resume)
};

static const struct of_device_id cdns_ti_of_match[] = {

--
2.43.2