On 08/09/16 20:35, Kevin Hilman wrote:
Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> writes:
This is a new driver for the USB PHY found in Meson8b and GXBB SoCs.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
I tested this on meson-gxbb-p200 with USB host and a mass storage
device.
Tested-by: Kevin Hilman <khilman@xxxxxxxxxxxx>
A minor question/comment below, for you and for Kishon...
[...]
+static int phy_meson_usb2_probe(struct platform_device *pdev)
+{
+ struct phy_meson_usb2_priv *priv;
+ struct resource *res;
+ struct phy *phy;
+ struct phy_provider *phy_provider;
+ int ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ priv->regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(priv->regs))
+ return PTR_ERR(priv->regs);
+
+ priv->clk_usb_general = devm_clk_get(&pdev->dev, "usb_general");
+ if (IS_ERR(priv->clk_usb_general))
+ return PTR_ERR(priv->clk_usb_general);
+
+ priv->clk_usb = devm_clk_get(&pdev->dev, "usb");
+ if (IS_ERR(priv->clk_usb))
+ return PTR_ERR(priv->clk_usb);
+
+ priv->dr_mode = of_usb_get_dr_mode_by_phy(pdev->dev.of_node, -1);
+ if (priv->dr_mode == USB_DR_MODE_UNKNOWN) {
+ dev_err(&pdev->dev,
+ "missing dual role configuration of the controller\n");
+ return -EINVAL;
+ }
+
+ phy = devm_phy_create(&pdev->dev, NULL, &phy_meson_usb2_ops);
+ if (IS_ERR(phy)) {
+ dev_err(&pdev->dev, "failed to create PHY\n");
+ return PTR_ERR(phy);
+ }
+
+ if (usb_reset_refcnt++ == 0) {
+ ret = device_reset(&pdev->dev);
+ if (ret) {
+ dev_err(&phy->dev, "Failed to reset USB PHY\n");
+ return ret;
+ }
+ }
The ref count + reset here looks like something that could/should be
handled in a runtime PM callback.
IOW, there should be a pm_runtime_get_sync() here, and in the
->runtime_resume() callback, the device_reset() would be called.
Runtime PM does the refcounting, and only calls ->runtime_resume() on
the 0 -> 1 transition.
This isn't a big deal for now, so I'll let Kishon decide, but using
runtime PM from the start will help enabling other PM features later.
I agree, pm_runtime would probably be the best place to handle >1
device with shared items such as reset.
The version I wrote, I simply enabled the clocks and reset the device
when probed to work around the shared reset.
--
Ben Dooks http://www.codethink.co.uk/
Senior Engineer Codethink - Providing Genius
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