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authorJon Anders Haugum <jonah@omegav.ntnu.no>2006-04-30 06:20:56 -0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-04-30 06:20:56 -0400
commitb32b19b8ffc05cbd3bf91c65e205f6a912ca15d9 (patch)
treecaadb31badac0101bde68eefc0cf8c89c55bb72b /drivers/serial
parent85835f442e5bbf9d3b8f6e574751da8db77016d2 (diff)
[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>
Diffstat (limited to 'drivers/serial')
-rw-r--r--drivers/serial/8250.c55
1 files 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)
362#define serial_inp(up, offset) serial_in(up, offset) 362#define serial_inp(up, offset) serial_in(up, offset)
363#define serial_outp(up, offset, value) serial_out(up, offset, value) 363#define serial_outp(up, offset, value) serial_out(up, offset, value)
364 364
365/* Uart divisor latch read */
366static inline int _serial_dl_read(struct uart_8250_port *up)
367{
368 return serial_inp(up, UART_DLL) | serial_inp(up, UART_DLM) << 8;
369}
370
371/* Uart divisor latch write */
372static inline void _serial_dl_write(struct uart_8250_port *up, int value)
373{
374 serial_outp(up, UART_DLL, value & 0xff);
375 serial_outp(up, UART_DLM, value >> 8 & 0xff);
376}
377
378#ifdef CONFIG_SERIAL_8250_AU1X00
379/* Au1x00 haven't got a standard divisor latch */
380static int serial_dl_read(struct uart_8250_port *up)
381{
382 if (up->port.iotype == UPIO_AU)
383 return __raw_readl(up->port.membase + 0x28);
384 else
385 return _serial_dl_read(up);
386}
387
388static void serial_dl_write(struct uart_8250_port *up, int value)
389{
390 if (up->port.iotype == UPIO_AU)
391 __raw_writel(value, up->port.membase + 0x28);
392 else
393 _serial_dl_write(up, value);
394}
395#else
396#define serial_dl_read(up) _serial_dl_read(up)
397#define serial_dl_write(up, value) _serial_dl_write(up, value)
398#endif
365 399
366/* 400/*
367 * For the 16C950 401 * For the 16C950
@@ -494,7 +528,8 @@ static void disable_rsa(struct uart_8250_port *up)
494 */ 528 */
495static int size_fifo(struct uart_8250_port *up) 529static int size_fifo(struct uart_8250_port *up)
496{ 530{
497 unsigned char old_fcr, old_mcr, old_dll, old_dlm, old_lcr; 531 unsigned char old_fcr, old_mcr, old_lcr;
532 unsigned short old_dl;
498 int count; 533 int count;
499 534
500 old_lcr = serial_inp(up, UART_LCR); 535 old_lcr = serial_inp(up, UART_LCR);
@@ -505,10 +540,8 @@ static int size_fifo(struct uart_8250_port *up)
505 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); 540 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
506 serial_outp(up, UART_MCR, UART_MCR_LOOP); 541 serial_outp(up, UART_MCR, UART_MCR_LOOP);
507 serial_outp(up, UART_LCR, UART_LCR_DLAB); 542 serial_outp(up, UART_LCR, UART_LCR_DLAB);
508 old_dll = serial_inp(up, UART_DLL); 543 old_dl = serial_dl_read(up);
509 old_dlm = serial_inp(up, UART_DLM); 544 serial_dl_write(up, 0x0001);
510 serial_outp(up, UART_DLL, 0x01);
511 serial_outp(up, UART_DLM, 0x00);
512 serial_outp(up, UART_LCR, 0x03); 545 serial_outp(up, UART_LCR, 0x03);
513 for (count = 0; count < 256; count++) 546 for (count = 0; count < 256; count++)
514 serial_outp(up, UART_TX, count); 547 serial_outp(up, UART_TX, count);
@@ -519,8 +552,7 @@ static int size_fifo(struct uart_8250_port *up)
519 serial_outp(up, UART_FCR, old_fcr); 552 serial_outp(up, UART_FCR, old_fcr);
520 serial_outp(up, UART_MCR, old_mcr); 553 serial_outp(up, UART_MCR, old_mcr);
521 serial_outp(up, UART_LCR, UART_LCR_DLAB); 554 serial_outp(up, UART_LCR, UART_LCR_DLAB);
522 serial_outp(up, UART_DLL, old_dll); 555 serial_dl_write(up, old_dl);
523 serial_outp(up, UART_DLM, old_dlm);
524 serial_outp(up, UART_LCR, old_lcr); 556 serial_outp(up, UART_LCR, old_lcr);
525 557
526 return count; 558 return count;
@@ -750,8 +782,7 @@ static void autoconfig_16550a(struct uart_8250_port *up)
750 782
751 serial_outp(up, UART_LCR, 0xE0); 783 serial_outp(up, UART_LCR, 0xE0);
752 784
753 quot = serial_inp(up, UART_DLM) << 8; 785 quot = serial_dl_read(up);
754 quot += serial_inp(up, UART_DLL);
755 quot <<= 3; 786 quot <<= 3;
756 787
757 status1 = serial_in(up, 0x04); /* EXCR1 */ 788 status1 = serial_in(up, 0x04); /* EXCR1 */
@@ -759,8 +790,7 @@ static void autoconfig_16550a(struct uart_8250_port *up)
759 status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */ 790 status1 |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
760 serial_outp(up, 0x04, status1); 791 serial_outp(up, 0x04, status1);
761 792
762 serial_outp(up, UART_DLL, quot & 0xff); 793 serial_dl_write(up, quot);
763 serial_outp(up, UART_DLM, quot >> 8);
764 794
765 serial_outp(up, UART_LCR, 0); 795 serial_outp(up, UART_LCR, 0);
766 796
@@ -1862,8 +1892,7 @@ serial8250_set_termios(struct uart_port *port, struct termios *termios,
1862 serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */ 1892 serial_outp(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
1863 } 1893 }
1864 1894
1865 serial_outp(up, UART_DLL, quot & 0xff); /* LS of divisor */ 1895 serial_dl_write(up, quot);
1866 serial_outp(up, UART_DLM, quot >> 8); /* MS of divisor */
1867 1896
1868 /* 1897 /*
1869 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR 1898 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR