[PATCH v1] usb: dwc2: reset AHB hclk domain before init
From: Yunzhi Li <hidden>
Date: 2015-08-11 02:28:41
Also in:
lkml
Subsystem:
designware usb2 drd ip driver, the rest, usb subsystem · Maintainers:
Minas Harutyunyan, Linus Torvalds, Greg Kroah-Hartman
We initiate dwc2 usb controller in BIOS, when kernel driver start-up we should reset AHB hclk domain to reset all AHB interface registers to default. Without this the FIFO value setting might be incorrect because calculating FIFO size need the power-on value of GRXFSIZ/GNPTXFSIZ/HPTXFSIZ registers. This patch could avoid warnning massage like in rk3288 platform: [ 2.074764] dwc2 ff580000.usb: 256 invalid for host_perio_tx_fifo_size. Check HW configuration. Signed-off-by: Yunzhi Li <redacted> --- drivers/usb/dwc2/platform.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 9093530..3da21ab 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c@@ -42,6 +42,7 @@ #include <linux/of_device.h> #include <linux/mutex.h> #include <linux/platform_device.h> +#include <linux/reset.h> #include <linux/usb/of.h>
@@ -165,6 +166,7 @@ static int dwc2_driver_probe(struct platform_device *dev) struct resource *res; struct phy *phy; struct usb_phy *uphy; + struct reset_control *rst; int retval; int irq;
@@ -189,6 +191,16 @@ static int dwc2_driver_probe(struct platform_device *dev) hsotg->dev = &dev->dev; + /* AHB hclk domain reset, set all AHB interface registers to default */ + rst = devm_reset_control_get_optional(&dev->dev, "ahb_reset"); + if (IS_ERR(rst)) { + dev_dbg(&dev->dev, "Can't get dwc2 AHB reset\n"); + } else { + reset_control_assert(rst); + udelay(5); + reset_control_deassert(rst); + } + /* * Use reasonable defaults so platforms don't have to provide these. */
--
2.0.0