RM9000 serial driver

Add support for the integrated serial ports of the MIPS RM9122 processor
and its relatives.

The patch also does some whitespace cleanup.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Thomas Koeller <thomas.koeller@baslerweb.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 95 insertions, 13 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 130d825e5438..7441a2cf523e 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1042,6 +1042,9 @@ config SOC_AU1X00
         select SYS_SUPPORTS_APM_EMULATION
         select SYS_SUPPORTS_KGDB
 
+config SERIAL_RM9000
+        bool
+
 config PNX8550
         bool
         select SOC_PNX8550
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 194362d9f5a3..c9832d963f1e 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -251,9 +251,16 @@ static const struct serial8250_config uart_config[] = {
                 .fcr            = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
                 .flags          = UART_CAP_FIFO | UART_CAP_UUE,
         },
+        [PORT_RM9000] = {
+                .name           = "RM9000",
+                .fifo_size      = 16,
+                .tx_loadsz      = 16,
+                .fcr            = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+                .flags          = UART_CAP_FIFO,
+        },
 };
 
-#ifdef CONFIG_SERIAL_8250_AU1X00
+#if defined (CONFIG_SERIAL_8250_AU1X00)
 
 /* Au1x00 UART hardware has a weird register layout */
 static const u8 au_io_in_map[] = {
@@ -289,6 +296,44 @@ static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)
         return au_io_out_map[offset];
 }
 
+#elif defined (CONFIG_SERIAL_8250_RM9K)
+
+static const u8
+        regmap_in[8] = {
+                [UART_RX]       = 0x00,
+                [UART_IER]      = 0x0c,
+                [UART_IIR]      = 0x14,
+                [UART_LCR]      = 0x1c,
+                [UART_MCR]      = 0x20,
+                [UART_LSR]      = 0x24,
+                [UART_MSR]      = 0x28,
+                [UART_SCR]      = 0x2c
+        },
+        regmap_out[8] = {
+                [UART_TX]       = 0x04,
+                [UART_IER]      = 0x0c,
+                [UART_FCR]      = 0x18,
+                [UART_LCR]      = 0x1c,
+                [UART_MCR]      = 0x20,
+                [UART_LSR]      = 0x24,
+                [UART_MSR]      = 0x28,
+                [UART_SCR]      = 0x2c
+        };
+
+static inline int map_8250_in_reg(struct uart_8250_port *up, int offset)
+{
+        if (up->port.iotype != UPIO_RM9000)
+                return offset;
+        return regmap_in[offset];
+}
+
+static inline int map_8250_out_reg(struct uart_8250_port *up, int offset)
+{
+        if (up->port.iotype != UPIO_RM9000)
+                return offset;
+        return regmap_out[offset];
+}
+
 #else
 
 /* sane hardware needs no mapping */
@@ -311,6 +356,7 @@ static unsigned int serial_in(struct uart_8250_port *up, int offset)
         case UPIO_DWAPB:
                 return readb(up->port.membase + offset);
 
+        case UPIO_RM9000:
         case UPIO_MEM32:
                 return readl(up->port.membase + offset);
 
@@ -348,6 +394,7 @@ serial_out(struct uart_8250_port *up, int offset, int value)
                 writeb(value, up->port.membase + offset);
                 break;
 
+        case UPIO_RM9000:
         case UPIO_MEM32:
                 writel(value, up->port.membase + offset);
                 break;
@@ -419,7 +466,7 @@ static inline void _serial_dl_write(struct uart_8250_port *up, int value)
         serial_outp(up, UART_DLM, value >> 8 & 0xff);
 }
 
-#ifdef CONFIG_SERIAL_8250_AU1X00
+#if defined (CONFIG_SERIAL_8250_AU1X00)
 /* Au1x00 haven't got a standard divisor latch */
 static int serial_dl_read(struct uart_8250_port *up)
 {
@@ -436,6 +483,24 @@ static void serial_dl_write(struct uart_8250_port *up, int value)
         else
                 _serial_dl_write(up, value);
 }
+#elif defined (CONFIG_SERIAL_8250_RM9K)
+static int serial_dl_read(struct uart_8250_port *up)
+{
+        return  (up->port.iotype == UPIO_RM9000) ?
+                (((__raw_readl(up->port.membase + 0x10) << 8) |
+                (__raw_readl(up->port.membase + 0x08) & 0xff)) & 0xffff) :
+                _serial_dl_read(up);
+}
+
+static void serial_dl_write(struct uart_8250_port *up, int value)
+{
+        if (up->port.iotype == UPIO_RM9000) {
+                __raw_writel(value, up->port.membase + 0x08);
+                __raw_writel(value >> 8, up->port.membase + 0x10);
+        } 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)
@@ -637,7 +702,7 @@ static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
  * its clones.  (We treat the broken original StarTech 16650 V1 as a
  * 16550, and why not?  Startech doesn't seem to even acknowledge its
  * existence.)
- * 
+ *
  * What evil have men's minds wrought...
  */
 static void autoconfig_has_efr(struct uart_8250_port *up)
@@ -690,7 +755,7 @@ static void autoconfig_has_efr(struct uart_8250_port *up)
                         up->bugs |= UART_BUG_QUOT;
                 return;
         }
-        
+
         /*
          * We check for a XR16C850 by setting DLL and DLM to 0, and then
          * reading back DLL and DLM.  The chip type depends on the DLM
@@ -833,7 +898,7 @@ static void autoconfig_16550a(struct uart_8250_port *up)
                         status1 &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
                         status1 |= 0x10;  /* 1.625 divisor for baud_base --> 921600 */
                         serial_outp(up, 0x04, status1);
-                        
+
                         serial_dl_write(up, quot);
 
                         serial_outp(up, UART_LCR, 0);
@@ -938,7 +1003,7 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
                 /*
                  * Do a simple existence test first; if we fail this,
                  * there's no point trying anything else.
-                 * 
+                 *
                  * 0x80 is used as a nonsense port to prevent against
                  * false positives due to ISA bus float.  The
                  * assumption is that 0x80 is a non-existent port;
@@ -977,7 +1042,7 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
         save_mcr = serial_in(up, UART_MCR);
         save_lcr = serial_in(up, UART_LCR);
 
-        /* 
+        /*
          * Check to see if a UART is really there.  Certain broken
          * internal modems based on the Rockwell chipset fail this
          * test, because they apparently don't implement the loopback
@@ -1084,7 +1149,7 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
         else
                 serial_outp(up, UART_IER, 0);
 
- out:   
+ out:
         spin_unlock_irqrestore(&up->port.lock, flags);
 //      restore_flags(flags);
         DEBUG_AUTOCONF("type=%s\n", uart_config[up->port.type].name);
@@ -1110,7 +1175,7 @@ static void autoconfig_irq(struct uart_8250_port *up)
         save_mcr = serial_inp(up, UART_MCR);
         save_ier = serial_inp(up, UART_IER);
         serial_outp(up, UART_MCR, UART_MCR_OUT1 | UART_MCR_OUT2);
-        
+
         irqs = probe_irq_on();
         serial_outp(up, UART_MCR, 0);
         udelay (10);
@@ -1175,8 +1240,11 @@ static void serial8250_start_tx(struct uart_port *port)
                 if (up->bugs & UART_BUG_TXEN) {
                         unsigned char lsr, iir;
                         lsr = serial_in(up, UART_LSR);
-                        iir = serial_in(up, UART_IIR);
-                        if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT)
+                        iir = serial_in(up, UART_IIR) & 0x0f;
+                        if ((up->port.type == PORT_RM9000) ?
+                                (lsr & UART_LSR_THRE &&
+                                (iir == UART_IIR_NO_INT || iir == UART_IIR_THRI)) :
+                                (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT))
                                 transmit_chars(up);
                 }
         }
@@ -1957,7 +2025,7 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
         /*
          * Ask the core to calculate the divisor for us.
          */
-        baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); 
+        baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
         quot = serial8250_get_divisor(port, baud);
 
         /*
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index ad9f321968e1..e9d927e3b8e6 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -254,6 +254,15 @@ config SERIAL_8250_AU1X00
           to this option.  The driver can handle 1 or 2 serial ports.
           If unsure, say N.
 
+config SERIAL_8250_RM9K
+        bool "Support for MIPS RM9xxx integrated serial port"
+        depends on SERIAL_8250 != n && SERIAL_RM9000
+        select SERIAL_8250_SHARE_IRQ
+        help
+          Selecting this option will add support for the integrated serial
+          port hardware found on MIPS RM9122 and similar processors.
+          If unsure, say N.
+
 comment "Non-8250 serial port support"
 
 config SERIAL_AMBA_PL010
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 8b5592e6aca4..d242c731491f 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -39,7 +39,8 @@
 #define PORT_RSA        13
 #define PORT_NS16550A   14
 #define PORT_XSCALE     15
-#define PORT_MAX_8250   15      /* max port ID */
+#define PORT_RM9000     16      /* PMC-Sierra RM9xxx internal UART */
+#define PORT_MAX_8250   16      /* max port ID */
 
 /*
  * ARM specific type numbers.  These are not currently guaranteed
@@ -231,6 +232,7 @@ struct uart_port {
 #define UPIO_AU                 (4)                     /* Au1x00 type IO */
 #define UPIO_TSI                (5)                     /* Tsi108/109 type IO */
 #define UPIO_DWAPB              (6)                     /* DesignWare APB UART */
+#define UPIO_RM9000             (7)                     /* RM9000 type IO */
 
         unsigned int            read_status_mask;       /* driver specific */
         unsigned int            ignore_status_mask;     /* driver specific */