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usb: cdns3-ti: run HW init at resume() if HW was reset

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At runtime_resume(), read the W1 (Wrapper Register 1) register to detect
if an hardware reset occurred. If it did, run the hardware init sequence.

This callback will be called at system-wide resume. Previously, if a
reset occurred during suspend, we would crash. The wrapper config had
not been written, leading to invalid register accesses inside cdns3.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20250205-s2r-cdns-v7-6-13658a271c3c@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Théo Lebrun
2025-03-14 09:18:02 +01:00
committed by Greg Kroah-Hartman
parent 24346dc291
commit 9925aa4b02
1 changed files with 25 additions and 0 deletions
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drivers/usb/cdns3/cdns3-ti.c
+25
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@@ -186,6 +186,12 @@ static int cdns_ti_probe(struct platform_device *pdev)
data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
/*
* The call below to pm_runtime_get_sync() MIGHT reset hardware, if it
* detects it as uninitialised. We want to enforce a reset at probe,
* and so do it manually here. This means the first runtime_resume()
* will be a no-op.
*/
cdns_ti_reset_and_init_hw(data);
pm_runtime_enable(dev);
@@ -230,6 +236,24 @@ static void cdns_ti_remove(struct platform_device *pdev)
platform_set_drvdata(pdev, NULL);
}
static int cdns_ti_runtime_resume(struct device *dev)
{
const u32 mask = USBSS_W1_PWRUP_RST | USBSS_W1_MODESTRAP_SEL;
struct cdns_ti *data = dev_get_drvdata(dev);
u32 w1;
w1 = cdns_ti_readl(data, USBSS_W1);
if ((w1 & mask) != mask)
cdns_ti_reset_and_init_hw(data);
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(pm_runtime_force_suspend, pm_runtime_force_resume)
};
static const struct of_device_id cdns_ti_of_match[] = {
{ .compatible = "ti,j721e-usb", },
{ .compatible = "ti,am64-usb", },
@@ -243,6 +267,7 @@ static struct platform_driver cdns_ti_driver = {
.driver = {
.name = "cdns3-ti",
.of_match_table = cdns_ti_of_match,
.pm = pm_ptr(&cdns_ti_pm_ops),
},
};