usb: gadget: fotg210: add w1c interrupt status support

Since hardware revision 1.11.0, the following interrupt status
registers are now W1C (i.e., write 1 clear):

1. Interrupt Source Group 0 Register (0x144) (EP0 Abort: BIT5)
2. Interrupt Source Group 2 Register (0x14C) (All bits)

And before revision 1.11.0, these registers are all R/W.
Which means software must write a 0 to clear the status.

Signed-off-by: Kuo-Jung Su <dantesu@faraday-tech.com>
CC: Marek Vasut <marex@denx.de>

diff --git a/drivers/usb/gadget/fotg210.c b/drivers/usb/gadget/fotg210.c
index 6e19db15fafeca32818d4be7bfe28fa033c2341b..cc5c507f875e0e5ccb44a826d4ecfe5acdd48d86 100644 (file)
--- a/drivers/usb/gadget/fotg210.c
+++ b/drivers/usb/gadget/fotg210.c
@@ -847,6 +847,13 @@ int usb_gadget_handle_interrupts(void)
        /* CX interrupts */
        if (gisr & GISR_GRP0) {
                st = readl(&regs->gisr0);
+               /*
+                * Write 1 and then 0 works for both W1C & RW.
+                *
+                * HW v1.11.0+: It's a W1C register (write 1 clear)
+                * HW v1.10.0-: It's a R/W register (write 0 clear)
+                */
+               writel(st & GISR0_CXABORT, &regs->gisr0);
                writel(0, &regs->gisr0);
 
                if (st & GISR0_CXERR)
@@ -873,6 +880,13 @@ int usb_gadget_handle_interrupts(void)
        /* Device Status Interrupts */
        if (gisr & GISR_GRP2) {
                st = readl(&regs->gisr2);
+               /*
+                * Write 1 and then 0 works for both W1C & RW.
+                *
+                * HW v1.11.0+: It's a W1C register (write 1 clear)
+                * HW v1.10.0-: It's a R/W register (write 0 clear)
+                */
+               writel(st, &regs->gisr2);
                writel(0, &regs->gisr2);
 
                if (st & GISR2_RESET)