[PATCH v2 2/3] ehci-platform: Add support for controllers with multiple reset lines

Rob Herring
2015-12-14T01:09:38Z

On Fri, Dec 11, 2015 at 04:41:59PM +0100, Hans de Goede wrote:
> From: Reinder de Haan <patchesrdh@mveas.com>
>
> At least the EHCI/OHCI found on the Allwinnner H3 SoC needs multiple
> reset lines, the controller will not initialize while the reset for
> its companion is still asserted, which means we need to de-assert
> 2 resets for the controller to work.
>
> Signed-off-by: Reinder de Haan <patchesrdh@mveas.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Acked-by: Rob Herring <robh@kernel.org>

> ---
> Changes in v2:
> -Use the new reset_control_[de]assert_shared reset-controller functions
> ---
> Documentation/devicetree/bindings/usb/usb-ehci.txt | 2 +-
> drivers/usb/host/ehci-platform.c | 47 +++++++++++++---------
> 2 files changed, 30 insertions(+), 19 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt
> index a12d601..0701812 100644
> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt
> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt
> @@ -18,7 +18,7 @@ Optional properties:
> - clocks : a list of phandle + clock specifier pairs
> - phys : phandle + phy specifier pair
> - phy-names : "usb"
> - - resets : phandle + reset specifier pair
> + - resets : a list of phandle + reset specifier pairs
>
> Example (Sequoia 440EPx):
> ehci at e0000300 {
> diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
> index bd7082f2..6fbf32a 100644
> --- a/drivers/usb/host/ehci-platform.c
> +++ b/drivers/usb/host/ehci-platform.c
> @@ -39,11 +39,12 @@
>
> #define DRIVER_DESC "EHCI generic platform driver"
> #define EHCI_MAX_CLKS 3
> +#define EHCI_MAX_RESETS 2
> #define hcd_to_ehci_priv(h) ((struct ehci_platform_priv *)hcd_to_ehci(h)->priv)
>
> struct ehci_platform_priv {
> struct clk *clks[EHCI_MAX_CLKS];
> - struct reset_control *rst;
> + struct reset_control *resets[EHCI_MAX_RESETS];
> struct phy **phys;
> int num_phys;
> bool reset_on_resume;
> @@ -149,7 +150,7 @@ static int ehci_platform_probe(struct platform_device *dev)
> struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
> struct ehci_platform_priv *priv;
> struct ehci_hcd *ehci;
> - int err, irq, phy_num, clk = 0;
> + int err, irq, phy_num, clk = 0, rst = 0;
>
> if (usb_disabled())
> return -ENODEV;
> @@ -232,18 +233,24 @@ static int ehci_platform_probe(struct platform_device *dev)
> break;
> }
> }
> - }
>
> - priv->rst = devm_reset_control_get_optional(&dev->dev, NULL);
> - if (IS_ERR(priv->rst)) {
> - err = PTR_ERR(priv->rst);
> - if (err == -EPROBE_DEFER)
> - goto err_put_clks;
> - priv->rst = NULL;
> - } else {
> - err = reset_control_deassert(priv->rst);
> - if (err)
> - goto err_put_clks;
> + for (rst = 0; rst < EHCI_MAX_RESETS; rst++) {
> + priv->resets[rst] =
> + of_reset_control_get_by_index(dev->dev.of_node,
> + rst);
> + if (IS_ERR(priv->resets[rst])) {
> + err = PTR_ERR(priv->resets[rst]);
> + if (err == -EPROBE_DEFER)
> + goto err_reset;
> + priv->resets[rst] = NULL;
> + break;
> + }
> + err = reset_control_deassert_shared(priv->resets[rst]);
> + if (err) {
> + reset_control_put(priv->resets[rst]);
> + goto err_reset;
> + }
> + }
> }
>
> if (pdata->big_endian_desc)
> @@ -300,8 +307,10 @@ err_power:
> if (pdata->power_off)
> pdata->power_off(dev);
> err_reset:
> - if (priv->rst)
> - reset_control_assert(priv->rst);
> + while (--rst >= 0) {
> + reset_control_assert_shared(priv->resets[rst]);
> + reset_control_put(priv->resets[rst]);
> + }
> err_put_clks:
> while (--clk >= 0)
> clk_put(priv->clks[clk]);
> @@ -319,15 +328,17 @@ static int ehci_platform_remove(struct platform_device *dev)
> struct usb_hcd *hcd = platform_get_drvdata(dev);
> struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
> struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
> - int clk;
> + int clk, rst;
>
> usb_remove_hcd(hcd);
>
> if (pdata->power_off)
> pdata->power_off(dev);
>
> - if (priv->rst)
> - reset_control_assert(priv->rst);
> + for (rst = 0; rst < EHCI_MAX_RESETS && priv->resets[rst]; rst++) {
> + reset_control_assert_shared(priv->resets[rst]);
> + reset_control_put(priv->resets[rst]);
> + }
>
> for (clk = 0; clk < EHCI_MAX_CLKS && priv->clks[clk]; clk++)
> clk_put(priv->clks[clk]);
> --
> 2.5.0
>
> --
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