From b32b19b8ffc05cbd3bf91c65e205f6a912ca15d9 Mon Sep 17 00:00:00 2001 From: Jon Anders Haugum Date: Sun, 30 Apr 2006 11:20:56 +0100 Subject: [PATCH] [SERIAL] 8250: set divisor register correctly for AMD Alchemy SoC uart Alchemy SoC uart have got a non-standard divisor register that needs some special handling. This patch adds divisor read/write functions with test and special handling for Alchemy internal uart. Signed-off-by: Jon Anders Haugum Signed-off-by: Russell King --- drivers/serial/8250.c | 55 +++++++++++++++++++++++++++++++++---------- 1 file changed, 42 insertions(+), 13 deletions(-) diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index d641ac4e976e..9cc74712795d 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -362,6 +362,40 @@ serial_out(struct uart_8250_port *up, int offset, int value) #define serial_inp(up, offset) serial_in(up, offset) #define serial_outp(up, offset, value) serial_out(up, offset, value) +/* Uart divisor latch read */ +static inline int _serial_dl_read(struct uart_8250_port *up) +{ + return serial_inp(up, UART_DLL) | serial_inp(up, UART_DLM) << 8; +} + +/* Uart divisor latch write */ +static inline void _serial_dl_write(struct uart_8250_port *up, int value) +{ + serial_outp(up, UART_DLL, value & 0xff); + serial_outp(up, UART_DLM, value >> 8 & 0xff); +} + +#ifdef CONFIG_SERIAL_8250_AU1X00 +/* Au1x00 haven't got a standard divisor latch */ +static int serial_dl_read(struct uart_8250_port *up) +{ + if (up->port.iotype == UPIO_AU) + return __raw_readl(up->port.membase + 0x28); + else + return _serial_dl_read(up); +} + +static void serial_dl_write(struct uart_8250_port *up, int value) +{ + if (up->port.iotype == UPIO_AU) + __raw_writel(value, up->port.membase + 0x28); + else + _serial_dl_write(up, value); +} +#else +#define serial_dl_read(up) _serial_dl_read(up) +#define serial_dl_write(up, value) _serial_dl_write(up, value) +#endif /* * For the 16C950 @@ -494,7 +528,8 @@ static void disable_rsa(struct uart_8250_port *up) */ static int size_fifo(struct uart_8250_port *up) { - unsigned char old_fcr, old_mcr, old_dll, old_dlm, old_lcr; + unsigned char old_fcr, old_mcr, old_lcr; + unsigned short old_dl; int count; old_lcr = serial_inp(up, UART_LCR); @@ -505,10 +540,8 @@ static int size_fifo(struct uart_8250_port *up) UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); serial_outp(up, UART_MCR, UART_MCR_LOOP); serial_outp(up, UART_LCR, UART_LCR_DLAB); - old_dll = serial_inp(up, UART_DLL); - old_dlm = serial_inp(up, UART_DLM); - serial_outp(up, UART_DLL, 0x01); - serial_outp(up, UART_DLM, 0x00); + old_dl = serial_dl_read(up); + serial_dl_write(up, 0x0001); serial_outp(up, UART_LCR, 0x03); for (count = 0; count < 256; count++) serial_outp(up, UART_TX, count); @@ -519,8 +552,7 @@ static int size_fifo(struct uart_8250_port *up) serial_outp(up, UART_FCR, old_fcr); serial_outp(up, UART_MCR, old_mcr); serial_outp(up, UART_LCR, UART_LCR_DLAB); - serial_outp(up, UART_DLL, old_dll); - serial_outp(up, UART_DLM, old_dlm); + serial_dl_write(up, old_dl); serial_outp(up, UART_LCR, old_lcr); return count; @@ -750,8 +782,7 @@ static void autoconfig_16550a(struct uart_8250_port *up) serial_outp(up, UART_LCR, 0xE0); - quot = serial_inp(up, UART_DLM) << 8; - quot += serial_inp(up, UART_DLL); + quot = serial_dl_read(up); quot <<= 3; status1 = serial_in(up, 0x04); /* EXCR1 */ @@ -759,8 +790,7 @@ static void autoconfig_16550a(struct uart_8250_port *up) status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */ serial_outp(up, 0x04, status1); - serial_outp(up, UART_DLL, quot & 0xff); - serial_outp(up, UART_DLM, quot >> 8); + serial_dl_write(up, quot); serial_outp(up, UART_LCR, 0); @@ -1862,8 +1892,7 @@ serial8250_set_termios(struct uart_port *port, struct termios *termios, serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */ } - serial_outp(up, UART_DLL, quot & 0xff); /* LS of divisor */ - serial_outp(up, UART_DLM, quot >> 8); /* MS of divisor */ + serial_dl_write(up, quot); /* * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR -- 2.34.1