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>

arch/mips/sibyte/bcm1480/setup.c

@@ -31,6 +31,7 @@
 unsigned int sb1_pass;
 unsigned int soc_pass;
 unsigned int soc_type;
+EXPORT_SYMBOL(soc_type);
 unsigned int periph_rev;
 unsigned int zbbus_mhz;
 

arch/mips/sibyte/sb1250/setup.c

@@ -31,6 +31,7 @@
 unsigned int sb1_pass;
 unsigned int soc_pass;
 unsigned int soc_type;
+EXPORT_SYMBOL(soc_type);
 unsigned int periph_rev;
 unsigned int zbbus_mhz;
 EXPORT_SYMBOL(zbbus_mhz);

drivers/serial/Kconfig

@@ -338,6 +338,34 @@ config SERIAL_AMBA_PL011_CONSOLE
 	  your boot loader (lilo or loadlin) about how to pass options to the
 	  kernel at boot time.)
 
+config SERIAL_SB1250_DUART
+	tristate "BCM1xxx on-chip DUART serial support"
+	depends on SIBYTE_SB1xxx_SOC=y
+	select SERIAL_CORE
+	default y
+	---help---
+	  Support for the asynchronous serial interface (DUART) included in
+	  the BCM1250 and derived System-On-a-Chip (SOC) devices.  Note that
+	  the letter D in DUART stands for "dual", which is how the device
+	  is implemented.  Depending on the SOC configuration there may be
+	  one or more DUARTs available of which all are handled.
+
+	  If unsure, say Y.  To compile this driver as a module, choose M here:
+	  the module will be called sb1250-duart.
+
+config SERIAL_SB1250_DUART_CONSOLE
+	bool "Support for console on a BCM1xxx DUART serial port"
+	depends on SERIAL_SB1250_DUART=y
+	select SERIAL_CORE_CONSOLE
+	default y
+	---help---
+	  If you say Y here, it will be possible to use a serial port as the
+	  system console (the system console is the device which receives all
+	  kernel messages and warnings and which allows logins in single user
+	  mode).
+
+	  If unsure, say Y.
+
 config SERIAL_ATMEL
 	bool "AT91 / AT32 on-chip serial port support"
 	depends on (ARM && ARCH_AT91) || AVR32

drivers/serial/Makefile

@@ -51,6 +51,7 @@ obj-$(CONFIG_SERIAL_MPC52xx) += mpc52xx_uart.o
 obj-$(CONFIG_SERIAL_ICOM) += icom.o
 obj-$(CONFIG_SERIAL_M32R_SIO) += m32r_sio.o
 obj-$(CONFIG_SERIAL_MPSC) += mpsc.o
+obj-$(CONFIG_SERIAL_SB1250_DUART) += sb1250-duart.o
 obj-$(CONFIG_ETRAX_SERIAL) += crisv10.o
 obj-$(CONFIG_SERIAL_JSM) += jsm/
 obj-$(CONFIG_SERIAL_TXX9) += serial_txx9.o

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.

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
 
 
 /*

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)
 
 /*

include/linux/serial_core.h

@@ -142,6 +142,9 @@
 /* Micrel KS8695 */
 #define PORT_KS8695	76
 
+/* Broadcom SB1250, etc. SOC */
+#define PORT_SB1250_DUART	77
+
 
 #ifdef __KERNEL__