From 0bcfd70ea11a5d6f2362be463513a60245a62baf Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Mon, 24 Dec 2007 19:40:05 +0800 Subject: [Blackfin] serial driver: fix bug - cache the bits of the LSR on systems where the LSR is read-to-clear Cache the bits of the LSR on systems where the LSR is read-to-clear so that we can safely read the LSR in random places. this fixes older parts where break/framing/parity/overflow was not being detected at all in PIO mode, and this fixes newer parts where break/framing/parity/overflow was being reported all the time without being cleared. Signed-off-by: Mike Frysinger Signed-off-by: Bryan Wu --- include/asm-blackfin/mach-bf537/bfin_serial_5xx.h | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'include/asm-blackfin/mach-bf537') diff --git a/include/asm-blackfin/mach-bf537/bfin_serial_5xx.h b/include/asm-blackfin/mach-bf537/bfin_serial_5xx.h index 86e45c379838..f18c517cc935 100644 --- a/include/asm-blackfin/mach-bf537/bfin_serial_5xx.h +++ b/include/asm-blackfin/mach-bf537/bfin_serial_5xx.h @@ -23,7 +23,6 @@ #define UART_GET_DLH(uart) bfin_read16(((uart)->port.membase + OFFSET_DLH)) #define UART_GET_IIR(uart) bfin_read16(((uart)->port.membase + OFFSET_IIR)) #define UART_GET_LCR(uart) bfin_read16(((uart)->port.membase + OFFSET_LCR)) -#define UART_GET_LSR(uart) bfin_read16(((uart)->port.membase + OFFSET_LSR)) #define UART_GET_GCTL(uart) bfin_read16(((uart)->port.membase + OFFSET_GCTL)) #define UART_PUT_CHAR(uart,v) bfin_write16(((uart)->port.membase + OFFSET_THR),v) @@ -58,6 +57,7 @@ struct bfin_serial_port { struct uart_port port; unsigned int old_status; + unsigned int lsr; #ifdef CONFIG_SERIAL_BFIN_DMA int tx_done; int tx_count; @@ -76,6 +76,23 @@ struct bfin_serial_port { #endif }; +/* The hardware clears the LSR bits upon read, so we need to cache + * some of the more fun bits in software so they don't get lost + * when checking the LSR in other code paths (TX). + */ +static inline unsigned int UART_GET_LSR(struct bfin_serial_port *uart) +{ + unsigned int lsr = bfin_read16(uart->port.membase + OFFSET_LSR); + uart->lsr |= (lsr & (BI|FE|PE|OE)); + return lsr | uart->lsr; +} + +static inline void UART_CLEAR_LSR(struct bfin_serial_port *uart) +{ + uart->lsr = 0; + bfin_write16(uart->port.membase + OFFSET_LSR, -1); +} + struct bfin_serial_port bfin_serial_ports[NR_PORTS]; struct bfin_serial_res { unsigned long uart_base_addr; -- cgit v1.2.3