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authorJon Anders Haugum <jonah@omegav.ntnu.no>2006-04-30 11:20:56 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-04-30 11:20:56 +0100
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)
#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