diff options
| author | Mike Frysinger <michael.frysinger@analog.com> | 2007-12-24 19:40:05 +0800 |
|---|---|---|
| committer | Bryan Wu <cooloney@kernel.org> | 2007-12-24 19:40:05 +0800 |
| commit | 0bcfd70ea11a5d6f2362be463513a60245a62baf (patch) | |
| tree | fdf47e68cc5fc916da5d985f797b262c36997c4e /include/asm-blackfin/mach-bf527/bfin_serial_5xx.h | |
| parent | 4c195ad88b7df54b2e7340dec3446aee6ca84cd1 (diff) | |
[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 <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Diffstat (limited to 'include/asm-blackfin/mach-bf527/bfin_serial_5xx.h')
| -rw-r--r-- | include/asm-blackfin/mach-bf527/bfin_serial_5xx.h | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/include/asm-blackfin/mach-bf527/bfin_serial_5xx.h b/include/asm-blackfin/mach-bf527/bfin_serial_5xx.h index 15dbc21eed8b..233c585efc1e 100644 --- a/include/asm-blackfin/mach-bf527/bfin_serial_5xx.h +++ b/include/asm-blackfin/mach-bf527/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; |