Hi,
I am looking at the Linux implementation for USB 2.0 driver on OMAP L138.
In function service_zero_data_request (file musb_gadget_ep0.c), when handling Set/Clear Feature, there are these MUSB_TXCSR_P_WZC_BITS and MUSB_RXCSR_P_WZC_BITS.
Based on the comment in musb_regs.h, it seems like these fields has to be written with one (in order to to maintain the original value ?) ...
Is it true as it is not mentioned in the user guide ?
/* TXCSR bits to avoid zeroing (write zero clears, write 1 ignored) */
#define MUSB_TXCSR_P_WZC_BITS \
(MUSB_TXCSR_P_INCOMPTX | MUSB_TXCSR_P_SENTSTALL \
| MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_FIFONOTEMPTY)
/* RXCSR bits to avoid zeroing (write zero clears, write 1 ignored) */
#define MUSB_RXCSR_P_WZC_BITS \
(MUSB_RXCSR_P_SENTSTALL | MUSB_RXCSR_P_OVERRUN \
| MUSB_RXCSR_RXPKTRDY)
rgds,
kc Wong