[SERIAL] Support Au1x00 8250 UARTs using the generic 8250 driver.

The offsets of the registers are in a different place, and
some parts cannot handle a full set of modem control signals.

Signed-off-by: Pantelis Antoniou <pantelis@embeddedalley.ocm>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

6 files changed, 183 insertions, 3 deletions

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index f47d2c454e33..186e96c47b3d 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -251,9 +251,53 @@ static const struct serial8250_config uart_config[] = {
         },
 };
 
+#ifdef CONFIG_SERIAL_8250_AU1X00
+
+/* Au1x00 UART hardware has a weird register layout */
+static const u8 au_io_in_map[] = {
+        [UART_RX]  = 0,
+        [UART_IER] = 2,
+        [UART_IIR] = 3,
+        [UART_LCR] = 5,
+        [UART_MCR] = 6,
+        [UART_LSR] = 7,
+        [UART_MSR] = 8,
+};
+
+static const u8 au_io_out_map[] = {
+        [UART_TX]  = 1,
+        [UART_IER] = 2,
+        [UART_FCR] = 4,
+        [UART_LCR] = 5,
+        [UART_MCR] = 6,
+};
+
+/* sane hardware needs no mapping */
+static inline int map_8250_in_reg(struct uart_8250_port *up, int offset)
+{
+        if (up->port.iotype != UPIO_AU)
+                return offset;
+        return au_io_in_map[offset];
+}
+
+static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)
+{
+        if (up->port.iotype != UPIO_AU)
+                return offset;
+        return au_io_out_map[offset];
+}
+
+#else
+
+/* sane hardware needs no mapping */
+#define map_8250_in_reg(up, offset) (offset)
+#define map_8250_out_reg(up, offset) (offset)
+
+#endif
+
 static _INLINE_ unsigned int serial_in(struct uart_8250_port *up, int offset)
 {
-        offset <<= up->port.regshift;
+        offset = map_8250_in_reg(up, offset) << up->port.regshift;
 
         switch (up->port.iotype) {
         case UPIO_HUB6:
@@ -266,6 +310,11 @@ static _INLINE_ unsigned int serial_in(struct uart_8250_port *up, int offset)
         case UPIO_MEM32:
                 return readl(up->port.membase + offset);
 
+#ifdef CONFIG_SERIAL_8250_AU1X00
+        case UPIO_AU:
+                return __raw_readl(up->port.membase + offset);
+#endif
+
         default:
                 return inb(up->port.iobase + offset);
         }
@@ -274,7 +323,7 @@ static _INLINE_ unsigned int serial_in(struct uart_8250_port *up, int offset)
 static _INLINE_ void
 serial_out(struct uart_8250_port *up, int offset, int value)
 {
-        offset <<= up->port.regshift;
+        offset = map_8250_out_reg(up, offset) << up->port.regshift;
 
         switch (up->port.iotype) {
         case UPIO_HUB6:
@@ -290,6 +339,12 @@ serial_out(struct uart_8250_port *up, int offset, int value)
                 writel(value, up->port.membase + offset);
                 break;
 
+#ifdef CONFIG_SERIAL_8250_AU1X00
+        case UPIO_AU:
+                __raw_writel(value, up->port.membase + offset);
+                break;
+#endif
+
         default:
                 outb(value, up->port.iobase + offset);
         }
@@ -910,6 +965,13 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
                 }
         }
 #endif
+
+#ifdef CONFIG_SERIAL_8250_AU1X00
+        /* if access method is AU, it is a 16550 with a quirk */
+        if (up->port.type == PORT_16550A && up->port.iotype == UPIO_AU)
+                up->bugs |= UART_BUG_NOMSR;
+#endif
+
         serial_outp(up, UART_LCR, save_lcr);
 
         if (up->capabilities != uart_config[up->port.type].flags) {
@@ -1057,6 +1119,10 @@ static void serial8250_enable_ms(struct uart_port *port)
 {
         struct uart_8250_port *up = (struct uart_8250_port *)port;
 
+        /* no MSR capabilities */
+        if (up->bugs & UART_BUG_NOMSR)
+                return;
+
         up->ier |= UART_IER_MSI;
         serial_out(up, UART_IER, up->ier);
 }
@@ -1774,7 +1840,8 @@ serial8250_set_termios(struct uart_port *port, struct termios *termios,
          * CTS flow control flag and modem status interrupts
          */
         up->ier &= ~UART_IER_MSI;
-        if (UART_ENABLE_MS(&up->port, termios->c_cflag))
+        if (!(up->bugs & UART_BUG_NOMSR) &&
+                        UART_ENABLE_MS(&up->port, termios->c_cflag))
                 up->ier |= UART_IER_MSI;
         if (up->capabilities & UART_CAP_UUE)
                 up->ier |= UART_IER_UUE | UART_IER_RTOIE;
diff --git a/drivers/serial/8250.h b/drivers/serial/8250.h
index b1b459efda52..a607b98016db 100644
--- a/drivers/serial/8250.h
+++ b/drivers/serial/8250.h
@@ -49,6 +49,7 @@ struct serial8250_config {
 
 #define UART_BUG_QUOT   (1 << 0)        /* UART has buggy quot LSB */
 #define UART_BUG_TXEN   (1 << 1)        /* UART has buggy TX IIR status */
+#define UART_BUG_NOMSR  (1 << 2)        /* UART has buggy MSR status bits (Au1x00) */
 
 #if defined(__i386__) && (defined(CONFIG_M386) || defined(CONFIG_M486))
 #define _INLINE_ inline
diff --git a/drivers/serial/8250_au1x00.c b/drivers/serial/8250_au1x00.c
new file mode 100644
index 000000000000..06ae8fbcc947
--- /dev/null
+++ b/drivers/serial/8250_au1x00.c
@@ -0,0 +1,102 @@
+/*
+ * Serial Device Initialisation for Au1x00
+ *
+ * (C) Copyright Embedded Alley Solutions, Inc 2005
+ * Author: Pantelis Antoniou <pantelis@embeddedalley.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/serial_core.h>
+#include <linux/signal.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <linux/serial_8250.h>
+
+#include <asm/mach-au1x00/au1000.h>
+
+#include "8250.h"
+
+#define PORT(_base, _irq)                               \
+        {                                               \
+                .iobase         = _base,                \
+                .membase        = (void __iomem *)_base,\
+                .mapbase        = _base,                \
+                .irq            = _irq,                 \
+                .uartclk        = 0,    /* filled */    \
+                .regshift       = 2,                    \
+                .iotype         = UPIO_AU,              \
+                .flags          = UPF_SKIP_TEST |       \
+                                  UPF_IOREMAP,          \
+        }
+
+static struct plat_serial8250_port au1x00_data[] = {
+#if defined(CONFIG_SOC_AU1000)
+        PORT(UART0_ADDR, AU1000_UART0_INT),
+        PORT(UART1_ADDR, AU1000_UART1_INT),
+        PORT(UART2_ADDR, AU1000_UART2_INT),
+        PORT(UART3_ADDR, AU1000_UART3_INT),
+#elif defined(CONFIG_SOC_AU1500)
+        PORT(UART0_ADDR, AU1500_UART0_INT),
+        PORT(UART3_ADDR, AU1500_UART3_INT),
+#elif defined(CONFIG_SOC_AU1100)
+        PORT(UART0_ADDR, AU1100_UART0_INT),
+        PORT(UART1_ADDR, AU1100_UART1_INT),
+        PORT(UART2_ADDR, AU1100_UART2_INT),
+        PORT(UART3_ADDR, AU1100_UART3_INT),
+#elif defined(CONFIG_SOC_AU1550)
+        PORT(UART0_ADDR, AU1550_UART0_INT),
+        PORT(UART1_ADDR, AU1550_UART1_INT),
+        PORT(UART2_ADDR, AU1550_UART2_INT),
+        PORT(UART3_ADDR, AU1550_UART3_INT),
+#elif defined(CONFIG_SOC_AU1200)
+        PORT(UART0_ADDR, AU1200_UART0_INT),
+        PORT(UART1_ADDR, AU1200_UART1_INT),
+#endif
+        { },
+};
+
+static struct platform_device au1x00_device = {
+        .name                   = "serial8250",
+        .id                     = PLAT8250_DEV_AU1X00,
+        .dev                    = {
+                .platform_data  = au1x00_data,
+        },
+};
+
+static int __init au1x00_init(void)
+{
+        int i;
+        unsigned int uartclk;
+
+        /* get uart clock */
+        uartclk = get_au1x00_uart_baud_base() * 16;
+
+        /* fill up uartclk */
+        for (i = 0; au1x00_data[i].flags ; i++)
+                au1x00_data[i].uartclk = uartclk;
+
+        return platform_device_register(&au1x00_device);
+}
+
+/* XXX: Yes, I know this doesn't yet work. */
+static void __exit au1x00_exit(void)
+{
+        platform_device_unregister(&au1x00_device);
+}
+
+module_init(au1x00_init);
+module_exit(au1x00_exit);
+
+MODULE_AUTHOR("Pantelis Antoniou <pantelis@embeddedalley.com>");
+MODULE_DESCRIPTION("8250 serial probe module for Au1x000 cards");
+MODULE_LICENSE("GPL");
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index b745a1b9e835..ff36f0c9fdad 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -207,6 +207,14 @@ config SERIAL_8250_ACORN
           system, say Y to this option.  The driver can handle 1, 2, or 3 port
           cards.  If unsure, say N.
 
+config SERIAL_8250_AU1X00
+        bool "AU1X00 serial port support"
+        depends on SERIAL_8250 != n && SOC_AU1X00
+        help
+          If you have an Au1x00 board and want to use the serial port, say Y
+          to this option.  The driver can handle 1 or 2 serial ports.
+          If unsure, say N.
+
 comment "Non-8250 serial port support"
 
 config SERIAL_AMBA_PL010
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 11c7dc483f93..d7c7c7180e33 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_SERIAL_8250_ACCENT) += 8250_accent.o
 obj-$(CONFIG_SERIAL_8250_BOCA) += 8250_boca.o
 obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o
 obj-$(CONFIG_SERIAL_8250_MCA) += 8250_mca.o
+obj-$(CONFIG_SERIAL_8250_AU1X00) += 8250_au1x00.o
 obj-$(CONFIG_SERIAL_AMBA_PL010) += amba-pl010.o
 obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o
 obj-$(CONFIG_SERIAL_CLPS711X) += clps711x.o
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 0745ce782974..427a23858076 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1959,6 +1959,7 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port)
                 break;
         case UPIO_MEM:
         case UPIO_MEM32:
+        case UPIO_AU:
                 snprintf(address, sizeof(address),
                          "MMIO 0x%lx", port->mapbase);
                 break;