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[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 <jonah@omegav.ntnu.no>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Jon Anders Haugum 2006-04-30 11:20:56 +01:00 committed by Russell King
parent 85835f442e
commit b32b19b8ff
1 changed files with 42 additions and 13 deletions
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55
drivers/serial/8250.c
View File

@ -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_inp(up, offset) serial_in(up, offset)
#define serial_outp(up, offset, value) serial_out(up, offset, value) #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 * 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) 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; int count;
old_lcr = serial_inp(up, UART_LCR); 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); UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
serial_outp(up, UART_MCR, UART_MCR_LOOP); serial_outp(up, UART_MCR, UART_MCR_LOOP);
serial_outp(up, UART_LCR, UART_LCR_DLAB); serial_outp(up, UART_LCR, UART_LCR_DLAB);
old_dll = serial_inp(up, UART_DLL); old_dl = serial_dl_read(up);
old_dlm = serial_inp(up, UART_DLM); serial_dl_write(up, 0x0001);
serial_outp(up, UART_DLL, 0x01);
serial_outp(up, UART_DLM, 0x00);
serial_outp(up, UART_LCR, 0x03); serial_outp(up, UART_LCR, 0x03);
for (count = 0; count < 256; count++) for (count = 0; count < 256; count++)
serial_outp(up, UART_TX, 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_FCR, old_fcr);
serial_outp(up, UART_MCR, old_mcr); serial_outp(up, UART_MCR, old_mcr);
serial_outp(up, UART_LCR, UART_LCR_DLAB); serial_outp(up, UART_LCR, UART_LCR_DLAB);
serial_outp(up, UART_DLL, old_dll); serial_dl_write(up, old_dl);
serial_outp(up, UART_DLM, old_dlm);
serial_outp(up, UART_LCR, old_lcr); serial_outp(up, UART_LCR, old_lcr);
return count; return count;
@ -750,8 +782,7 @@ static void autoconfig_16550a(struct uart_8250_port *up)
serial_outp(up, UART_LCR, 0xE0); serial_outp(up, UART_LCR, 0xE0);
quot = serial_inp(up, UART_DLM) << 8; quot = serial_dl_read(up);
quot += serial_inp(up, UART_DLL);
quot <<= 3; quot <<= 3;
status1 = serial_in(up, 0x04); /* EXCR1 */ 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 */ status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
serial_outp(up, 0x04, status1); serial_outp(up, 0x04, status1);
serial_outp(up, UART_DLL, quot & 0xff); serial_dl_write(up, quot);
serial_outp(up, UART_DLM, quot >> 8);
serial_outp(up, UART_LCR, 0); 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_LCR, cval | UART_LCR_DLAB);/* set DLAB */
} }
serial_outp(up, UART_DLL, quot & 0xff); /* LS of divisor */ serial_dl_write(up, quot);
serial_outp(up, UART_DLM, quot >> 8); /* MS of divisor */
/* /*
* LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR