| Message ID | 1399923274-6017-6-git-send-email-maxime.ripard@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 12 May 2014, Maxime Ripard wrote: > From: Boris BREZILLON <boris.brezillon@free-electrons.com> > > On the Allwinner's A31 SoC the reset line connected to the EHCI IP has to > be deasserted for the EHCI block to be usable. > > Add support for an optional reset controller that will be deasserted on > power off and asserted on power on. > > Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> > Reviewed-by: Hans de Goede <hdegoede@redhat.com> ... > @@ -208,6 +210,18 @@ static int ehci_platform_probe(struct platform_device *dev) > } > } > > + 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; > + } > + > if (pdata->big_endian_desc) > ehci->big_endian_desc = 1; > if (pdata->big_endian_mmio) You don't re-assert the reset control if an error happens later on during probe. Was that intentional? Alan Stern
On Mon, May 12, 2014 at 04:06:16PM -0400, Alan Stern wrote: > On Mon, 12 May 2014, Maxime Ripard wrote: > > > From: Boris BREZILLON <boris.brezillon@free-electrons.com> > > > > On the Allwinner's A31 SoC the reset line connected to the EHCI IP has to > > be deasserted for the EHCI block to be usable. > > > > Add support for an optional reset controller that will be deasserted on > > power off and asserted on power on. > > > > Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com> > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> > > Reviewed-by: Hans de Goede <hdegoede@redhat.com> > > ... > > > @@ -208,6 +210,18 @@ static int ehci_platform_probe(struct platform_device *dev) > > } > > } > > > > + 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; > > + } > > + > > if (pdata->big_endian_desc) > > ehci->big_endian_desc = 1; > > if (pdata->big_endian_mmio) > > You don't re-assert the reset control if an error happens later on > during probe. Was that intentional? No, it wasn't. I'll resubmit another version. Thanks, Maxime
diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt index ff151ec084c4..43c1a4e06767 100644 --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt @@ -15,6 +15,7 @@ Optional properties: - clocks : a list of phandle + clock specifier pairs - phys : phandle + phy specifier pair - phy-names : "usb" + - resets : phandle + reset specifier pair Example (Sequoia 440EPx): ehci@e0000300 { diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c index c7dd93aad20c..8bb15eda9713 100644 --- a/drivers/usb/host/ehci-platform.c +++ b/drivers/usb/host/ehci-platform.c @@ -29,6 +29,7 @@ #include <linux/of.h> #include <linux/phy/phy.h> #include <linux/platform_device.h> +#include <linux/reset.h> #include <linux/usb.h> #include <linux/usb/hcd.h> #include <linux/usb/ehci_pdriver.h> @@ -41,6 +42,7 @@ struct ehci_platform_priv { struct clk *clks[EHCI_MAX_CLKS]; + struct reset_control *rst; struct phy *phy; }; @@ -208,6 +210,18 @@ static int ehci_platform_probe(struct platform_device *dev) } } + 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; + } + if (pdata->big_endian_desc) ehci->big_endian_desc = 1; if (pdata->big_endian_mmio) @@ -280,6 +294,9 @@ static int ehci_platform_remove(struct platform_device *dev) if (pdata->power_off) pdata->power_off(dev); + if (priv->rst) + reset_control_assert(priv->rst); + for (clk = 0; clk < EHCI_MAX_CLKS && priv->clks[clk]; clk++) clk_put(priv->clks[clk]);