[ARM] 3029/1: Add HWUART support for PXA 255/26x

Patch from Matt Reimer

Adds support for HWUART on PXA 255 / 26x. This patch originally came from
http://svn.rungie.com/svn/gumstix-buildroot/trunk/sources/kernel-patches/000-gumstix-hwuart.patch
and has been tweaked by me.
Signed-off-by: Matt Reimer <mreimer@vpop.net>
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-pxa/generic.c

@@ -253,6 +253,10 @@ static struct platform_device stuart_device = {
 	.name		= "pxa2xx-uart",
 	.id		= 2,
 };
+static struct platform_device hwuart_device = {
+	.name		= "pxa2xx-uart",
+	.id		= 3,
+};
 
 static struct resource i2c_resources[] = {
 	{
@@ -310,7 +314,19 @@ static struct platform_device *devices[] __initdata = {
 
 static int __init pxa_init(void)
 {
-	return platform_add_devices(devices, ARRAY_SIZE(devices));
+	int cpuid, ret;
+
+	ret = platform_add_devices(devices, ARRAY_SIZE(devices));
+	if (ret)
+		return ret;
+
+	/* Only add HWUART for PXA255/26x; PXA210/250/27x do not have it. */
+	cpuid = read_cpuid(CPUID_ID);
+	if (((cpuid >> 4) & 0xfff) == 0x2d0 ||
+	    ((cpuid >> 4) & 0xfff) == 0x290)
+		ret = platform_device_register(&hwuart_device);
+
+	return ret;
 }
 
 subsys_initcall(pxa_init);

drivers/serial/pxa.c

@@ -358,6 +358,9 @@ static int serial_pxa_startup(struct uart_port *port)
 	unsigned long flags;
 	int retval;
 
+	if (port->line == 3) /* HWUART */
+		up->mcr |= UART_MCR_AFE;
+	else
 	up->mcr = 0;
 
 	/*
@@ -481,8 +484,10 @@ serial_pxa_set_termios(struct uart_port *port, struct termios *termios,
 
 	if ((up->port.uartclk / quot) < (2400 * 16))
 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
-	else
+	else if ((up->port.uartclk / quot) < (230400 * 16))
 		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
+	else
+		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;
 
 	/*
 	 * Ok, we're now changing the port state.  Do it with
@@ -772,6 +777,20 @@ static struct uart_pxa_port serial_pxa_ports[] = {
 		.ops		= &serial_pxa_pops,
 		.line		= 2,
 	},
+  }, {  /* HWUART */
+	.name	= "HWUART",
+	.cken	= CKEN4_HWUART,
+	.port = {
+		.type		= PORT_PXA,
+		.iotype		= UPIO_MEM,
+		.membase	= (void *)&HWUART,
+		.mapbase	= __PREG(HWUART),
+		.irq		= IRQ_HWUART,
+		.uartclk	= 921600 * 16,
+		.fifosize	= 64,
+		.ops		= &serial_pxa_pops,
+		.line		= 3,
+	},
   }
 };
 

include/asm-arm/arch-pxa/pxa-regs.h

@@ -326,6 +326,25 @@
 #define STDLL		__REG(0x40700000)  /* Divisor Latch Low Register (DLAB = 1) (read/write) */
 #define STDLH		__REG(0x40700004)  /* Divisor Latch High Register (DLAB = 1) (read/write) */
 
+/* Hardware UART (HWUART) */
+#define HWUART		HWRBR
+#define HWRBR		__REG(0x41600000)  /* Receive Buffer Register (read only) */
+#define HWTHR		__REG(0x41600000)  /* Transmit Holding Register (write only) */
+#define HWIER		__REG(0x41600004)  /* Interrupt Enable Register (read/write) */
+#define HWIIR		__REG(0x41600008)  /* Interrupt ID Register (read only) */
+#define HWFCR		__REG(0x41600008)  /* FIFO Control Register (write only) */
+#define HWLCR		__REG(0x4160000C)  /* Line Control Register (read/write) */
+#define HWMCR		__REG(0x41600010)  /* Modem Control Register (read/write) */
+#define HWLSR		__REG(0x41600014)  /* Line Status Register (read only) */
+#define HWMSR		__REG(0x41600018)  /* Modem Status Register (read only) */
+#define HWSPR		__REG(0x4160001C)  /* Scratch Pad Register (read/write) */
+#define HWISR		__REG(0x41600020)  /* Infrared Selection Register (read/write) */
+#define HWFOR		__REG(0x41600024)  /* Receive FIFO Occupancy Register (read only) */
+#define HWABR		__REG(0x41600028)  /* Auto-Baud Control Register (read/write) */
+#define HWACR		__REG(0x4160002C)  /* Auto-Baud Count Register (read only) */
+#define HWDLL		__REG(0x41600000)  /* Divisor Latch Low Register (DLAB = 1) (read/write) */
+#define HWDLH		__REG(0x41600004)  /* Divisor Latch High Register (DLAB = 1) (read/write) */
+
 #define IER_DMAE	(1 << 7)	/* DMA Requests Enable */
 #define IER_UUE		(1 << 6)	/* UART Unit Enable */
 #define IER_NRZE	(1 << 5)	/* NRZ coding Enable */
@@ -1250,9 +1269,13 @@
 #define GPIO40_FFDTR		40	/* FFUART data terminal Ready */
 #define GPIO41_FFRTS		41	/* FFUART request to send */
 #define GPIO42_BTRXD		42	/* BTUART receive data */
+#define GPIO42_HWRXD		42	/* HWUART receive data */
 #define GPIO43_BTTXD		43	/* BTUART transmit data */
+#define GPIO43_HWTXD		43	/* HWUART transmit data */
 #define GPIO44_BTCTS		44	/* BTUART clear to send */
+#define GPIO44_HWCTS		44	/* HWUART clear to send */
 #define GPIO45_BTRTS		45	/* BTUART request to send */
+#define GPIO45_HWRTS		45	/* HWUART request to send */
 #define GPIO45_AC97_SYSCLK	45	/* AC97 System Clock */
 #define GPIO46_ICPRXD		46	/* ICP receive data */
 #define GPIO46_STRXD		46	/* STD_UART receive data */
@@ -1378,17 +1401,26 @@
 #define GPIO40_FFDTR_MD		(40 | GPIO_ALT_FN_2_OUT)
 #define GPIO41_FFRTS_MD		(41 | GPIO_ALT_FN_2_OUT)
 #define GPIO42_BTRXD_MD		(42 | GPIO_ALT_FN_1_IN)
+#define GPIO42_HWRXD_MD		(42 | GPIO_ALT_FN_3_IN)
 #define GPIO43_BTTXD_MD		(43 | GPIO_ALT_FN_2_OUT)
+#define GPIO43_HWTXD_MD		(43 | GPIO_ALT_FN_3_OUT)
 #define GPIO44_BTCTS_MD		(44 | GPIO_ALT_FN_1_IN)
+#define GPIO44_HWCTS_MD		(44 | GPIO_ALT_FN_3_IN)
 #define GPIO45_BTRTS_MD		(45 | GPIO_ALT_FN_2_OUT)
+#define GPIO45_HWRTS_MD		(45 | GPIO_ALT_FN_3_OUT)
 #define GPIO45_SYSCLK_AC97_MD		(45 | GPIO_ALT_FN_1_OUT)
 #define GPIO46_ICPRXD_MD	(46 | GPIO_ALT_FN_1_IN)
 #define GPIO46_STRXD_MD		(46 | GPIO_ALT_FN_2_IN)
 #define GPIO47_ICPTXD_MD	(47 | GPIO_ALT_FN_2_OUT)
 #define GPIO47_STTXD_MD		(47 | GPIO_ALT_FN_1_OUT)
 #define GPIO48_nPOE_MD		(48 | GPIO_ALT_FN_2_OUT)
+#define GPIO48_HWTXD_MD         (48 | GPIO_ALT_FN_1_OUT)
+#define GPIO48_nPOE_MD          (48 | GPIO_ALT_FN_2_OUT)
+#define GPIO49_HWRXD_MD		(49 | GPIO_ALT_FN_1_IN)
 #define GPIO49_nPWE_MD		(49 | GPIO_ALT_FN_2_OUT)
 #define GPIO50_nPIOR_MD		(50 | GPIO_ALT_FN_2_OUT)
+#define GPIO50_HWCTS_MD         (50 | GPIO_ALT_FN_1_IN)
+#define GPIO51_HWRTS_MD         (51 | GPIO_ALT_FN_1_OUT)
 #define GPIO51_nPIOW_MD		(51 | GPIO_ALT_FN_2_OUT)
 #define GPIO52_nPCE_1_MD	(52 | GPIO_ALT_FN_2_OUT)
 #define GPIO53_nPCE_2_MD	(53 | GPIO_ALT_FN_2_OUT)
@@ -1763,6 +1795,7 @@
 #define CKEN7_BTUART	(1 << 7)	/* BTUART Unit Clock Enable */
 #define CKEN6_FFUART	(1 << 6)	/* FFUART Unit Clock Enable */
 #define CKEN5_STUART	(1 << 5)	/* STUART Unit Clock Enable */
+#define CKEN4_HWUART	(1 << 4)	/* HWUART Unit Clock Enable */
 #define CKEN4_SSP3	(1 << 4)	/* SSP3 Unit Clock Enable */
 #define CKEN3_SSP	(1 << 3)	/* SSP Unit Clock Enable */
 #define CKEN3_SSP2	(1 << 3)	/* SSP2 Unit Clock Enable */

include/asm-arm/arch-pxa/uncompress.h

@@ -12,6 +12,7 @@
 #define FFUART		((volatile unsigned long *)0x40100000)
 #define BTUART		((volatile unsigned long *)0x40200000)
 #define STUART		((volatile unsigned long *)0x40700000)
+#define HWUART		((volatile unsigned long *)0x41600000)
 
 #define UART		FFUART