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@xxxxxxxxxxxxxx>
---
--- linux-2.6.16-rc5/drivers/serial/8250.c.orig 2006-03-03 02:12:10.000000000 +0100
+++ linux-2.6.16-rc5/drivers/serial/8250.c 2006-03-03 02:16:19.000000000 +0100
@@ -362,6 +362,40 @@ serial_out(struct uart_8250_port *up, in
#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
*/
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_po
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_po
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;
@@ -533,22 +565,20 @@ static int size_fifo(struct uart_8250_po
*/
static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
{
- unsigned char old_dll, old_dlm, old_lcr;
+ unsigned char old_lcr;
unsigned int id;
+ unsigned short old_dl;
old_lcr = serial_inp(p, UART_LCR);
serial_outp(p, UART_LCR, UART_LCR_DLAB);
- old_dll = serial_inp(p, UART_DLL);
- old_dlm = serial_inp(p, UART_DLM);
+ old_dl = serial_dl_read(p);
- serial_outp(p, UART_DLL, 0);
- serial_outp(p, UART_DLM, 0);
+ serial_dl_write(p, 0);
- id = serial_inp(p, UART_DLL) | serial_inp(p, UART_DLM) << 8;
+ id = serial_dl_read(p);
- serial_outp(p, UART_DLL, old_dll);
- serial_outp(p, UART_DLM, old_dlm);
+ serial_dl_write(p, old_dl);
serial_outp(p, UART_LCR, old_lcr);
return id;
@@ -750,8 +780,7 @@ static void autoconfig_16550a(struct uar
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 +788,7 @@ static void autoconfig_16550a(struct uar
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 +1890,7 @@ serial8250_set_termios(struct uart_port
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
