sb1250-duart.c: SB1250 DUART serial support

This is a driver for the SB1250 DUART, a dual serial port implementation
included in the Broadcom family of SOCs descending from the SiByte SB1250
MIPS64 chip multiprocessor.  It is a new implementation replacing the
old-fashioned driver currently present in the linux-mips.org tree.  It
supports all the usual features one would expect from a(n asynchronous)
serial driver, including modem line control (as far as hardware supports it
-- there is edge detection logic missing from the DCD and RI lines and the
driver does not implement polling of these lines at the moment), the serial
console, BREAK transmission and reception, including the magic SysRq.  The
receive FIFO threshold is not maintained though.

The driver was tested with a SWARM board which uses a BCM1250 SOC (which is
dual MIPS64 CMP) and has both ports of the single DUART implemented wired
externally.  Both were tested.  Testing included using the ports as
terminal lines at 1200bps (which is the ports minimum), 115200bps and a
couple of random speeds inbetween.  The modem lines were verified to
operate correctly.  No testing was performed with a use as a network
interface, like with SLIP or PPP.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 68 insertions, 45 deletions

diff --git a/include/asm-mips/sibyte/bcm1480_regs.h b/include/asm-mips/sibyte/bcm1480_regs.h
index bda391d3af85..2738c1366f66 100644
--- a/include/asm-mips/sibyte/bcm1480_regs.h
+++ b/include/asm-mips/sibyte/bcm1480_regs.h
@@ -220,17 +220,25 @@
 #define A_BCM1480_DUART(chan)               ((((chan)&2) == 0)? A_BCM1480_DUART0 : A_BCM1480_DUART1)
 
 #define BCM1480_DUART_CHANREG_SPACING       0x100
-#define A_BCM1480_DUART_CHANREG(chan,reg)   (A_BCM1480_DUART(chan) \
-                                     + BCM1480_DUART_CHANREG_SPACING*((chan)&1) \
-                                     + (reg))
-#define R_BCM1480_DUART_CHANREG(chan,reg)   (BCM1480_DUART_CHANREG_SPACING*((chan)&1) + (reg))
-
-#define R_BCM1480_DUART_IMRREG(chan)        (R_DUART_IMR_A + ((chan)&1)*DUART_IMRISR_SPACING)
-#define R_BCM1480_DUART_ISRREG(chan)        (R_DUART_ISR_A + ((chan)&1)*DUART_IMRISR_SPACING)
-
-#define A_BCM1480_DUART_IMRREG(chan)        (A_BCM1480_DUART(chan) + R_BCM1480_DUART_IMRREG(chan))
-#define A_BCM1480_DUART_ISRREG(chan)        (A_BCM1480_DUART(chan) + R_BCM1480_DUART_ISRREG(chan))
-#define A_BCM1480_DUART_IN_PORT(chan)       (A_BCM1480_DUART(chan) + R_DUART_INP_ORT)
+#define A_BCM1480_DUART_CHANREG(chan, reg)                              \
+        (A_BCM1480_DUART(chan) +                                        \
+         BCM1480_DUART_CHANREG_SPACING * (((chan) & 1) + 1) + (reg))
+#define A_BCM1480_DUART_CTRLREG(chan, reg)                              \
+        (A_BCM1480_DUART(chan) +                                        \
+         BCM1480_DUART_CHANREG_SPACING * 3 + (reg))
+
+#define R_BCM1480_DUART_IMRREG(chan)                                    \
+        (R_DUART_IMR_A + ((chan) & 1) * DUART_IMRISR_SPACING)
+#define R_BCM1480_DUART_ISRREG(chan)                                    \
+        (R_DUART_ISR_A + ((chan) & 1) * DUART_IMRISR_SPACING)
+
+#define A_BCM1480_DUART_IMRREG(chan)                                    \
+        (A_BCM1480_DUART_CTRLREG((chan), R_BCM1480_DUART_IMRREG(chan)))
+#define A_BCM1480_DUART_ISRREG(chan)                                    \
+        (A_BCM1480_DUART_CTRLREG((chan), R_BCM1480_DUART_ISRREG(chan)))
+
+#define A_BCM1480_DUART_IN_PORT(chan)                                   \
+        (A_BCM1480_DUART_CTRLREG((chan), R_DUART_IN_PORT))
 
 /*
  * These constants are the absolute addresses.
diff --git a/include/asm-mips/sibyte/sb1250_regs.h b/include/asm-mips/sibyte/sb1250_regs.h
index da7c188993c9..220b7e94f1bf 100644
--- a/include/asm-mips/sibyte/sb1250_regs.h
+++ b/include/asm-mips/sibyte/sb1250_regs.h
@@ -272,59 +272,69 @@
     ********************************************************************* */
 
 
-#if SIBYTE_HDR_FEATURE_1250_112x                /* This MC only on 1250 & 112x */
+#if SIBYTE_HDR_FEATURE_1250_112x    /* This MC only on 1250 & 112x */
 #define R_DUART_NUM_PORTS           2
 
 #define A_DUART                     0x0010060000
 
 #define DUART_CHANREG_SPACING       0x100
-#define A_DUART_CHANREG(chan,reg)   (A_DUART + DUART_CHANREG_SPACING*(chan) + (reg))
-#define R_DUART_CHANREG(chan,reg)   (DUART_CHANREG_SPACING*(chan) + (reg))
+
+#define A_DUART_CHANREG(chan, reg)                                      \
+        (A_DUART + DUART_CHANREG_SPACING * ((chan) + 1) + (reg))
 #endif  /* 1250 & 112x */
 
-#define R_DUART_MODE_REG_1          0x100
-#define R_DUART_MODE_REG_2          0x110
-#define R_DUART_STATUS              0x120
-#define R_DUART_CLK_SEL             0x130
-#define R_DUART_CMD                 0x150
-#define R_DUART_RX_HOLD             0x160
-#define R_DUART_TX_HOLD             0x170
+#define R_DUART_MODE_REG_1          0x000
+#define R_DUART_MODE_REG_2          0x010
+#define R_DUART_STATUS              0x020
+#define R_DUART_CLK_SEL             0x030
+#define R_DUART_CMD                 0x050
+#define R_DUART_RX_HOLD             0x060
+#define R_DUART_TX_HOLD             0x070
 
 #if SIBYTE_HDR_FEATURE(1250, PASS2) || SIBYTE_HDR_FEATURE(112x, PASS1) || SIBYTE_HDR_FEATURE_CHIP(1480)
-#define R_DUART_FULL_CTL            0x140
-#define R_DUART_OPCR_X              0x180
-#define R_DUART_AUXCTL_X            0x190
-#endif /* 1250 PASS2 || 112x PASS1 || 1480*/
+#define R_DUART_FULL_CTL            0x040
+#define R_DUART_OPCR_X              0x080
+#define R_DUART_AUXCTL_X            0x090
+#endif /* 1250 PASS2 || 112x PASS1 || 1480 */
 
 
 /*
  * The IMR and ISR can't be addressed with A_DUART_CHANREG,
- * so use this macro instead.
+ * so use these macros instead.
  */
 
-#define R_DUART_AUX_CTRL            0x310
-#define R_DUART_ISR_A               0x320
-#define R_DUART_IMR_A               0x330
-#define R_DUART_ISR_B               0x340
-#define R_DUART_IMR_B               0x350
-#define R_DUART_OUT_PORT            0x360
-#define R_DUART_OPCR                0x370
-#define R_DUART_IN_PORT             0x380
+#if SIBYTE_HDR_FEATURE_1250_112x    /* This MC only on 1250 & 112x */
+#define DUART_IMRISR_SPACING        0x20
+#define DUART_INCHNG_SPACING        0x10
 
-#define R_DUART_SET_OPR             0x3B0
-#define R_DUART_CLEAR_OPR           0x3C0
+#define A_DUART_CTRLREG(reg)                                            \
+        (A_DUART + DUART_CHANREG_SPACING * 3 + (reg))
 
-#define DUART_IMRISR_SPACING        0x20
+#define R_DUART_IMRREG(chan)                                            \
+        (R_DUART_IMR_A + (chan) * DUART_IMRISR_SPACING)
+#define R_DUART_ISRREG(chan)                                            \
+        (R_DUART_ISR_A + (chan) * DUART_IMRISR_SPACING)
+#define R_DUART_INCHREG(chan)                                           \
+        (R_DUART_IN_CHNG_A + (chan) * DUART_INCHNG_SPACING)
 
-#if SIBYTE_HDR_FEATURE_1250_112x                /* This MC only on 1250 & 112x */
-#define R_DUART_IMRREG(chan)        (R_DUART_IMR_A + (chan)*DUART_IMRISR_SPACING)
-#define R_DUART_ISRREG(chan)        (R_DUART_ISR_A + (chan)*DUART_IMRISR_SPACING)
-
-#define A_DUART_IMRREG(chan)        (A_DUART + R_DUART_IMRREG(chan))
-#define A_DUART_ISRREG(chan)        (A_DUART + R_DUART_ISRREG(chan))
+#define A_DUART_IMRREG(chan)        A_DUART_CTRLREG(R_DUART_IMRREG(chan))
+#define A_DUART_ISRREG(chan)        A_DUART_CTRLREG(R_DUART_ISRREG(chan))
+#define A_DUART_INCHREG(chan)       A_DUART_CTRLREG(R_DUART_INCHREG(chan))
 #endif  /* 1250 & 112x */
 
-
+#define R_DUART_AUX_CTRL            0x010
+#define R_DUART_ISR_A               0x020
+#define R_DUART_IMR_A               0x030
+#define R_DUART_ISR_B               0x040
+#define R_DUART_IMR_B               0x050
+#define R_DUART_OUT_PORT            0x060
+#define R_DUART_OPCR                0x070
+#define R_DUART_IN_PORT             0x080
+
+#define R_DUART_SET_OPR             0x0B0
+#define R_DUART_CLEAR_OPR           0x0C0
+#define R_DUART_IN_CHNG_A           0x0D0
+#define R_DUART_IN_CHNG_B           0x0E0
 
 
 /*
diff --git a/include/asm-mips/sibyte/sb1250_uart.h b/include/asm-mips/sibyte/sb1250_uart.h
index e87045e62bf0..cf74fedcbef1 100644
--- a/include/asm-mips/sibyte/sb1250_uart.h
+++ b/include/asm-mips/sibyte/sb1250_uart.h
@@ -75,7 +75,8 @@
 #define V_DUART_PARITY_MODE_ADD_FIXED V_DUART_PARITY_MODE(K_DUART_PARITY_MODE_ADD_FIXED)
 #define V_DUART_PARITY_MODE_NONE      V_DUART_PARITY_MODE(K_DUART_PARITY_MODE_NONE)
 
-#define M_DUART_ERR_MODE            _SB_MAKEMASK1(5)    /* must be zero */
+#define M_DUART_TX_IRQ_SEL_TXRDY    0
+#define M_DUART_TX_IRQ_SEL_TXEMPT   _SB_MAKEMASK1(5)
 
 #define M_DUART_RX_IRQ_SEL_RXRDY    0
 #define M_DUART_RX_IRQ_SEL_RXFULL   _SB_MAKEMASK1(6)
@@ -246,10 +247,13 @@
 
 #define M_DUART_ISR_BRK_A           _SB_MAKEMASK1(2)
 #define M_DUART_ISR_IN_A            _SB_MAKEMASK1(3)
+#define M_DUART_ISR_ALL_A           _SB_MAKEMASK(4,0)
+
 #define M_DUART_ISR_TX_B            _SB_MAKEMASK1(4)
 #define M_DUART_ISR_RX_B            _SB_MAKEMASK1(5)
 #define M_DUART_ISR_BRK_B           _SB_MAKEMASK1(6)
 #define M_DUART_ISR_IN_B            _SB_MAKEMASK1(7)
+#define M_DUART_ISR_ALL_B           _SB_MAKEMASK(4,4)
 
 /*
  * DUART Channel A Interrupt Status Register (Table 10-17)
@@ -262,6 +266,7 @@
 #define M_DUART_ISR_RX              _SB_MAKEMASK1(1)
 #define M_DUART_ISR_BRK             _SB_MAKEMASK1(2)
 #define M_DUART_ISR_IN              _SB_MAKEMASK1(3)
+#define M_DUART_ISR_ALL             _SB_MAKEMASK(4,0)
 #define M_DUART_ISR_RESERVED        _SB_MAKEMASK(4,4)
 
 /*