From beab697ab4b2962e3d741b476abe443baad0933d Mon Sep 17 00:00:00 2001 From: Marc St-Jean Date: Sun, 6 May 2007 14:48:45 -0700 Subject: serial driver PMC MSP71xx Serial driver patch for the PMC-Sierra MSP71xx devices. There are three different fixes: 1 Fix for DesignWare APB THRE errata: In brief, this is a non-standard 16550 in that the THRE interrupt will not re-assert itself simply by disabling and re-enabling the THRI bit in the IER, it is only re-enabled if a character is actually sent out. It appears that the "8250-uart-backup-timer.patch" in the "mm" tree also fixes it so we have dropped our initial workaround. This patch now needs to be applied on top of that "mm" patch. 2 Fix for Busy Detect on LCR write: The DesignWare APB UART has a feature which causes a new Busy Detect interrupt to be generated if it's busy when the LCR is written. This fix saves the value of the LCR and rewrites it after clearing the interrupt. 3 Workaround for interrupt/data concurrency issue: The SoC needs to ensure that writes that can cause interrupts to be cleared reach the UART before returning from the ISR. This fix reads a non-destructive register on the UART so the read transaction completion ensures the previously queued write transaction has also completed. Signed-off-by: Marc St-Jean Cc: Russell King Cc: Ralf Baechle Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/serial_reg.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/serial_reg.h') diff --git a/include/linux/serial_reg.h b/include/linux/serial_reg.h index 3c8a6aa7741..1c5ed7d92b0 100644 --- a/include/linux/serial_reg.h +++ b/include/linux/serial_reg.h @@ -38,6 +38,8 @@ #define UART_IIR_RDI 0x04 /* Receiver data interrupt */ #define UART_IIR_RLSI 0x06 /* Receiver line status interrupt */ +#define UART_IIR_BUSY 0x07 /* DesignWare APB Busy Detect */ + #define UART_FCR 2 /* Out: FIFO Control Register */ #define UART_FCR_ENABLE_FIFO 0x01 /* Enable the FIFO */ #define UART_FCR_CLEAR_RCVR 0x02 /* Clear the RCVR FIFO */ -- cgit v1.2.3-70-g09d2