[PATCH] usb: cdns2: Fix controller reset issue

From: Pawel Laszczak
Date: Mon Sep 02 2024 - 07:29:40 EST


Patch fixes the procedure of resetting controller.
The CPUCTRL register is write only and reading returns 0.
Waiting for reset to complite is incorrect.

Fixes: 3eb1f1efe204 ("usb: cdns2: Add main part of Cadence USBHS driver")
cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
---
drivers/usb/gadget/udc/cdns2/cdns2-gadget.c | 12 +++---------
drivers/usb/gadget/udc/cdns2/cdns2-gadget.h | 9 +++++++++
2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c b/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c
index 0eed0e03842c..d394affb7072 100644
--- a/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c
+++ b/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c
@@ -2251,7 +2251,6 @@ static int cdns2_gadget_start(struct cdns2_device *pdev)
{
u32 max_speed;
void *buf;
- int val;
int ret;

pdev->usb_regs = pdev->regs;
@@ -2261,14 +2260,9 @@ static int cdns2_gadget_start(struct cdns2_device *pdev)
pdev->adma_regs = pdev->regs + CDNS2_ADMA_REGS_OFFSET;

/* Reset controller. */
- set_reg_bit_8(&pdev->usb_regs->cpuctrl, CPUCTRL_SW_RST);
-
- ret = readl_poll_timeout_atomic(&pdev->usb_regs->cpuctrl, val,
- !(val & CPUCTRL_SW_RST), 1, 10000);
- if (ret) {
- dev_err(pdev->dev, "Error: reset controller timeout\n");
- return -EINVAL;
- }
+ writeb(CPUCTRL_SW_RST | CPUCTRL_UPCLK | CPUCTRL_WUEN,
+ &pdev->usb_regs->cpuctrl);
+ usleep_range(5, 10);

usb_initialize_gadget(pdev->dev, &pdev->gadget, NULL);

diff --git a/drivers/usb/gadget/udc/cdns2/cdns2-gadget.h b/drivers/usb/gadget/udc/cdns2/cdns2-gadget.h
index 71e2f62d653a..b5d5ec12e986 100644
--- a/drivers/usb/gadget/udc/cdns2/cdns2-gadget.h
+++ b/drivers/usb/gadget/udc/cdns2/cdns2-gadget.h
@@ -292,8 +292,17 @@ struct cdns2_usb_regs {
#define SPEEDCTRL_HSDISABLE BIT(7)

/* CPUCTRL- bitmasks. */
+/* UP clock enable */
+#define CPUCTRL_UPCLK BIT(0)
/* Controller reset bit. */
#define CPUCTRL_SW_RST BIT(1)
+/**
+ * If the wuen bit is ‘1’, the upclken is automatically set to ‘1’ after
+ * detecting rising edge of wuintereq interrupt. If the wuen bit is ‘0’,
+ * the wuintereq interrupt is ignored.
+ */
+#define CPUCTRL_WUEN BIT(7)
+

/**
* struct cdns2_adma_regs - ADMA controller registers.
--
2.43.0