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ohci-platform: Add support for controllers with multiple reset lines
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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: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Hans de Goede authored and Greg Kroah-Hartman committed Jun 8, 2016
1 parent cab4328 commit 62d9694
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Showing 2 changed files with 24 additions and 21 deletions.
2 changes: 1 addition & 1 deletion Documentation/devicetree/bindings/usb/usb-ohci.txt
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@ 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:

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43 changes: 23 additions & 20 deletions drivers/usb/host/ohci-platform.c
Original file line number Diff line number Diff line change
Expand Up @@ -33,11 +33,12 @@

#define DRIVER_DESC "OHCI generic platform driver"
#define OHCI_MAX_CLKS 3
#define OHCI_MAX_RESETS 2
#define hcd_to_ohci_priv(h) ((struct ohci_platform_priv *)hcd_to_ohci(h)->priv)

struct ohci_platform_priv {
struct clk *clks[OHCI_MAX_CLKS];
struct reset_control *rst;
struct reset_control *resets[OHCI_MAX_RESETS];
struct phy **phys;
int num_phys;
};
Expand Down Expand Up @@ -117,7 +118,7 @@ static int ohci_platform_probe(struct platform_device *dev)
struct usb_ohci_pdata *pdata = dev_get_platdata(&dev->dev);
struct ohci_platform_priv *priv;
struct ohci_hcd *ohci;
int err, irq, phy_num, clk = 0;
int err, irq, phy_num, clk = 0, rst = 0;

if (usb_disabled())
return -ENODEV;
Expand Down Expand Up @@ -195,19 +196,21 @@ static int ohci_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 < OHCI_MAX_RESETS; rst++) {
priv->resets[rst] =
devm_reset_control_get_shared_by_index(
&dev->dev, 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(priv->resets[rst]);
if (err)
goto err_reset;
}
}

if (pdata->big_endian_desc)
Expand Down Expand Up @@ -265,8 +268,8 @@ static int ohci_platform_probe(struct platform_device *dev)
if (pdata->power_off)
pdata->power_off(dev);
err_reset:
if (priv->rst)
reset_control_assert(priv->rst);
while (--rst >= 0)
reset_control_assert(priv->resets[rst]);
err_put_clks:
while (--clk >= 0)
clk_put(priv->clks[clk]);
Expand All @@ -284,15 +287,15 @@ static int ohci_platform_remove(struct platform_device *dev)
struct usb_hcd *hcd = platform_get_drvdata(dev);
struct usb_ohci_pdata *pdata = dev_get_platdata(&dev->dev);
struct ohci_platform_priv *priv = hcd_to_ohci_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 < OHCI_MAX_RESETS && priv->resets[rst]; rst++)
reset_control_assert(priv->resets[rst]);

for (clk = 0; clk < OHCI_MAX_CLKS && priv->clks[clk]; clk++)
clk_put(priv->clks[clk]);
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