[PATCH RESEND v4 6/8] usb: ohci-platform: Enable optional use of reset controller

From: Maxime Ripard
Date: Tue May 13 2014 - 11:45:57 EST


The OHCI controllers used in the Allwinner A31 are asserted in reset using a
global reset controller.

Add optional support for such a controller in the OHCI platform driver.

Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
---
Documentation/devicetree/bindings/usb/usb-ohci.txt | 1 +
drivers/usb/host/ohci-platform.c | 27 +++++++++++++++++++---
2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/usb/usb-ohci.txt b/Documentation/devicetree/bindings/usb/usb-ohci.txt
index 45f67d91e888..b968a1aea995 100644
--- a/Documentation/devicetree/bindings/usb/usb-ohci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-ohci.txt
@@ -12,6 +12,7 @@ Optional properties:
- clocks : a list of phandle + clock specifier pairs
- phys : phandle + phy specifier pair
- phy-names : "usb"
+- resets : phandle + reset specifier pair

Example:

diff --git a/drivers/usb/host/ohci-platform.c b/drivers/usb/host/ohci-platform.c
index b6002c951c5c..4369299064c7 100644
--- a/drivers/usb/host/ohci-platform.c
+++ b/drivers/usb/host/ohci-platform.c
@@ -24,6 +24,7 @@
#include <linux/err.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
+#include <linux/reset.h>
#include <linux/usb/ohci_pdriver.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
@@ -36,6 +37,7 @@

struct ohci_platform_priv {
struct clk *clks[OHCI_MAX_CLKS];
+ struct reset_control *rst;
struct phy *phy;
};

@@ -191,6 +193,19 @@ 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;
}

if (pdata->big_endian_desc)
@@ -203,7 +218,7 @@ static int ohci_platform_probe(struct platform_device *dev)
dev_err(&dev->dev,
"Error: CONFIG_USB_OHCI_BIG_ENDIAN_MMIO not set\n");
err = -EINVAL;
- goto err_put_clks;
+ goto err_reset;
}
#endif
#ifndef CONFIG_USB_OHCI_BIG_ENDIAN_DESC
@@ -211,14 +226,14 @@ static int ohci_platform_probe(struct platform_device *dev)
dev_err(&dev->dev,
"Error: CONFIG_USB_OHCI_BIG_ENDIAN_DESC not set\n");
err = -EINVAL;
- goto err_put_clks;
+ goto err_reset;
}
#endif

if (pdata->power_on) {
err = pdata->power_on(dev);
if (err < 0)
- goto err_put_clks;
+ goto err_reset;
}

hcd->rsrc_start = res_mem->start;
@@ -242,6 +257,9 @@ static int ohci_platform_probe(struct platform_device *dev)
err_power:
if (pdata->power_off)
pdata->power_off(dev);
+err_reset:
+ if (priv->rst)
+ reset_control_assert(priv->rst);
err_put_clks:
while (--clk >= 0)
clk_put(priv->clks[clk]);
@@ -266,6 +284,9 @@ static int ohci_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 < OHCI_MAX_CLKS && priv->clks[clk]; clk++)
clk_put(priv->clks[clk]);

--
1.9.3

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