usb: ehci-platform: add optional reset controller retrieval
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>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c
index c7dd93a..2f5b9ce 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 @@
}
}
+ 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)
@@ -218,7 +232,7 @@
dev_err(&dev->dev,
"Error: CONFIG_USB_EHCI_BIG_ENDIAN_MMIO not set\n");
err = -EINVAL;
- goto err_put_clks;
+ goto err_reset;
}
#endif
#ifndef CONFIG_USB_EHCI_BIG_ENDIAN_DESC
@@ -226,14 +240,14 @@
dev_err(&dev->dev,
"Error: CONFIG_USB_EHCI_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;
@@ -256,6 +270,9 @@
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]);
@@ -280,6 +297,9 @@
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]);