usb: dwc3-am62: fix module unload/reload behavior

As runtime PM is enabled, the module can be runtime
suspended when .remove() is called.

Do a pm_runtime_get_sync() to make sure module is active
before doing any register operations.

Doing a pm_runtime_put_sync() should disable the refclk
so no need to disable it again.

Fixes the below warning at module removel.

[   39.705310] ------------[ cut here ]------------
[   39.710004] clk:162:3 already disabled
[   39.713941] WARNING: CPU: 0 PID: 921 at drivers/clk/clk.c:1090 clk_core_disable+0xb0/0xb8

We called of_platform_populate() in .probe() so call the
cleanup function of_platform_depopulate() in .remove().
Get rid of the now unnnecessary dwc3_ti_remove_core().
Without this, module re-load doesn't work properly.

Fixes: e8784c0aec03 ("drivers: usb: dwc3: Add AM62 USB wrapper driver")
Cc: stable@vger.kernel.org # v5.19+
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Link: https://lore.kernel.org/r/20240227-for-v6-9-am62-usb-errata-3-0-v4-1-0ada8ddb0767@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/dwc3-am62.c b/drivers/usb/dwc3/dwc3-am62.c
index 90a587bc29b74e533212f41e1a25fcda9655d68f..f85603b7f7c5e7549f57687211d5539380e47fa7 100644 (file)
--- a/drivers/usb/dwc3/dwc3-am62.c
+++ b/drivers/usb/dwc3/dwc3-am62.c
@@ -267,21 +267,14 @@ err_pm_disable:
        return ret;
 }
 
-static int dwc3_ti_remove_core(struct device *dev, void *c)
-{
-       struct platform_device *pdev = to_platform_device(dev);
-
-       platform_device_unregister(pdev);
-       return 0;
-}
-
 static void dwc3_ti_remove(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
        struct dwc3_am62 *am62 = platform_get_drvdata(pdev);
        u32 reg;
 
-       device_for_each_child(dev, NULL, dwc3_ti_remove_core);
+       pm_runtime_get_sync(dev);
+       of_platform_depopulate(dev);
 
        /* Clear mode valid bit */
        reg = dwc3_ti_readl(am62, USBSS_MODE_CONTROL);
@@ -289,7 +282,6 @@ static void dwc3_ti_remove(struct platform_device *pdev)
        dwc3_ti_writel(am62, USBSS_MODE_CONTROL, reg);
 
        pm_runtime_put_sync(dev);
-       clk_disable_unprepare(am62->usb2_refclk);
        pm_runtime_disable(dev);
        pm_runtime_set_suspended(dev);
 }