Hello,
2014/1/8 Hans de Goede <hdegoede@xxxxxxxxxx>:
> Add support for ohci-platform instantiation from devicetree, including
> optionally getting clks and a phy from devicetree, and enabling / disabling
> those on power_on / off.
>
> This should allow using ohci-platform from devicetree in various cases.
> Specifically after this commit it can be used for the ohci controller found
> on Allwinner sunxi SoCs.
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> .../devicetree/bindings/usb/platform-ohci.txt | 25 ++++
> drivers/usb/host/ohci-platform.c | 148 ++++++++++++++++++---
> 2 files changed, 153 insertions(+), 20 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/usb/platform-ohci.txt
>
> diff --git a/Documentation/devicetree/bindings/usb/platform-ohci.txt b/Documentation/devicetree/bindings/usb/platform-ohci.txt
> new file mode 100644
> index 0000000..44bfa57
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/platform-ohci.txt
ohci-mmio might be a better name than platform maybe?
[snip]
> +static int ohci_platform_power_on(struct platform_device *dev)
> +{
> + struct usb_hcd *hcd = platform_get_drvdata(dev);
> + struct ohci_platform_priv *priv =
> + (struct ohci_platform_priv *)hcd_to_ohci(hcd)->priv;
> + int clk, ret;
> +
> + for (clk = 0; priv->clks[clk] && clk < OHCI_MAX_CLKS; clk++) {
> + ret = clk_prepare_enable(priv->clks[clk]);
> + if (ret)
> + goto err_disable_clks;
> + }
Do we really need to cap this to OHCI_MAX_CLKS, the next driver which
has 4 clocks will have to bump this, so maybe a linked-list would be
best?
> +
> + if (priv->phy) {
> + ret = phy_init(priv->phy);
> + if (ret)
> + goto err_disable_clks;
> +
> + ret = phy_power_on(priv->phy);
> + if (ret)
> + goto err_exit_phy;
> + }
Although I do value the idea of having DT probing for ohci-platform,
ehci-platform et al, I am not sure if this really belongs in the
generic OHCI platform driver, or if we should rather have small glue
drivers which register the ohci-platform driver and which provides all
the platform-specific power_on, power_off, suspend callbacks to the
ohci platform driver? Such glue driver would be the one which gets
probed based off a specific compatible string a
At first glance it does look like this covers 80% of the existing OHCI
drivers out there, so this is good. We might also want to support
clock pointers provided via platform_data so we can remove ohci-at91,
ohci-ep93xx, ohci-spear and friends in the future.
ohci-ppc-of could also probably be removed once we add quirks and
endian properties parsing to ohci-platform?
> +
> + return 0;
> +
> +err_exit_phy:
> + phy_exit(priv->phy);
> +err_disable_clks:
> + while (--clk >= 0)
> + clk_disable_unprepare(priv->clks[clk]);
> +
> + return ret;
> +}
> +
> +static void ohci_platform_power_off(struct platform_device *dev)
> +{
> + struct usb_hcd *hcd = platform_get_drvdata(dev);
> + struct ohci_platform_priv *priv =
> + (struct ohci_platform_priv *)hcd_to_ohci(hcd)->priv;
> + int clk;
> +
> + if (priv->phy) {
> + phy_power_off(priv->phy);
> + phy_exit(priv->phy);
> + }
> +
> + for (clk = OHCI_MAX_CLKS - 1; clk >= 0; clk--)
> + if (priv->clks[clk])
> + clk_disable_unprepare(priv->clks[clk]);
> +}
> +
> static struct hc_driver __read_mostly ohci_platform_hc_driver;
>
> static const struct ohci_driver_overrides platform_overrides __initconst = {
> - .product_desc = "Generic Platform OHCI controller",
> - .reset = ohci_platform_reset,
> + .product_desc = "Generic Platform OHCI controller",
> + .reset = ohci_platform_reset,
> + .extra_priv_size = sizeof(struct ohci_platform_priv),
> +};
> +
> +static struct usb_ohci_pdata ohci_platform_defaults = {
> + .power_on = ohci_platform_power_on,
> + .power_suspend = ohci_platform_power_off,
> + .power_off = ohci_platform_power_off,
> };
>
> static int ohci_platform_probe(struct platform_device *dev)
> @@ -60,12 +128,24 @@ static int ohci_platform_probe(struct platform_device *dev)
> struct usb_hcd *hcd;
> struct resource *res_mem;
> struct usb_ohci_pdata *pdata = dev_get_platdata(&dev->dev);
> - int irq;
> - int err = -ENOMEM;
> + int clk, irq, err;
> + char name[8];
>
> + /*
> + * Use reasonable defaults so platforms don't have to provide these
> + * with DT probing on ARM.
> + */
> if (!pdata) {
> - WARN_ON(1);
> - return -ENODEV;
> + pdata = dev->dev.platform_data = &ohci_platform_defaults;
> + /*
> + * Right now device-tree probed devices don't get dma_mask set.
> + * Since shared usb code relies on it, set it here for now.
> + * Once we have dma capability bindings this can go away.
> + */
> + err = dma_coerce_mask_and_coherent(&dev->dev,
> + DMA_BIT_MASK(32));
> + if (err)
> + return err;
> }
>
> if (usb_disabled())
> @@ -83,17 +163,40 @@ static int ohci_platform_probe(struct platform_device *dev)
> return -ENXIO;
> }
>
> + hcd = usb_create_hcd(&ohci_platform_hc_driver, &dev->dev,
> + dev_name(&dev->dev));
> + if (!hcd)
> + return -ENOMEM;
> +
> + if (pdata == &ohci_platform_defaults) {
> + struct ohci_platform_priv *priv = (struct ohci_platform_priv *)
> + hcd_to_ohci(hcd)->priv;
> +
> + priv->phy = devm_phy_get(&dev->dev, "phy0");
Does this work with a more than one OHCI controller which could
possibly have a dedicated PHY?
> + if (IS_ERR(priv->phy)) {
> + err = PTR_ERR(priv->phy);
> + if (err == -EPROBE_DEFER)
> + goto err_put_hcd;
> + priv->phy = NULL;
> + }
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