[ARM] 3369/1: ep93xx: add core cirrus ep93xx support

Patch from Lennert Buytenhek

This patch adds support for the Cirrus ep93xx series of CPUs.  The
ep93xx is an ARM920T based CPU with two VICs, PL010 based UARTs,
IrDA, MaverickCrunch floating point coprocessor, between 24 and 64
GPIOs, ethernet, OHCI USB and, depending on the model, pcmcia, raster
engine, graphics accelerator, IDE controller and a bunch of other
stuff.

This patch adds the core ep93xx support code, and support for the
Glomation GESBC-9312-sx and the Technologic Systems TS-72xx SBCs.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 173 insertions, 0 deletions

diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c
new file mode 100644
index 0000000..f831f74
--- /dev/null
+++ b/arch/arm/mach-ep93xx/core.c
@@ -0,0 +1,173 @@
+/*
+ * arch/arm/mach-ep93xx/core.c
+ * Core routines for Cirrus EP93xx chips.
+ *
+ * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ *
+ * Thanks go to Michael Burian and Ray Lehtiniemi for their key
+ * role in the ep93xx linux community.
+ *
+ * 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/config.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/serial.h>
+#include <linux/tty.h>
+#include <linux/bitops.h>
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_core.h>
+#include <linux/device.h>
+#include <linux/mm.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/delay.h>
+#include <linux/amba/bus.h>
+
+#include <asm/types.h>
+#include <asm/setup.h>
+#include <asm/memory.h>
+#include <asm/hardware.h>
+#include <asm/irq.h>
+#include <asm/system.h>
+#include <asm/tlbflush.h>
+#include <asm/pgtable.h>
+#include <asm/io.h>
+
+#include <asm/mach/map.h>
+#include <asm/mach/time.h>
+#include <asm/mach/irq.h>
+
+#include <asm/hardware/vic.h>
+
+
+/*************************************************************************
+ * Static I/O mappings that are needed for all EP93xx platforms
+ *************************************************************************/
+static struct map_desc ep93xx_io_desc[] __initdata = {
+	{
+		.virtual	= EP93XX_AHB_VIRT_BASE,
+		.pfn		= __phys_to_pfn(EP93XX_AHB_PHYS_BASE),
+		.length		= EP93XX_AHB_SIZE,
+		.type		= MT_DEVICE,
+	}, {
+		.virtual	= EP93XX_APB_VIRT_BASE,
+		.pfn		= __phys_to_pfn(EP93XX_APB_PHYS_BASE),
+		.length		= EP93XX_APB_SIZE,
+		.type		= MT_DEVICE,
+	},
+};
+
+void __init ep93xx_map_io(void)
+{
+	iotable_init(ep93xx_io_desc, ARRAY_SIZE(ep93xx_io_desc));
+}
+
+
+/*************************************************************************
+ * Timer handling for EP93xx
+ *************************************************************************
+ * The ep93xx has four internal timers.  Timers 1, 2 (both 16 bit) and
+ * 3 (32 bit) count down at 508 kHz, are self-reloading, and can generate
+ * an interrupt on underflow.  Timer 4 (40 bit) counts down at 983.04 kHz,
+ * is free-running, and can't generate interrupts.
+ *
+ * The 508 kHz timers are ideal for use for the timer interrupt, as the
+ * most common values of HZ divide 508 kHz nicely.  We pick one of the 16
+ * bit timers (timer 1) since we don't need more than 16 bits of reload
+ * value as long as HZ >= 8.
+ *
+ * The higher clock rate of timer 4 makes it a better choice than the
+ * other timers for use in gettimeoffset(), while the fact that it can't
+ * generate interrupts means we don't have to worry about not being able
+ * to use this timer for something else.  We also use timer 4 for keeping
+ * track of lost jiffies.
+ */
+static unsigned int last_jiffy_time;
+
+#define TIMER4_TICKS_PER_JIFFY		((CLOCK_TICK_RATE + (HZ/2)) / HZ)
+
+static int ep93xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	write_seqlock(&xtime_lock);
+
+	__raw_writel(1, EP93XX_TIMER1_CLEAR);
+	while (__raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time
+						>= TIMER4_TICKS_PER_JIFFY) {
+		last_jiffy_time += TIMER4_TICKS_PER_JIFFY;
+		timer_tick(regs);
+	}
+
+	write_sequnlock(&xtime_lock);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction ep93xx_timer_irq = {
+	.name		= "ep93xx timer",
+	.flags		= SA_INTERRUPT | SA_TIMER,
+	.handler	= ep93xx_timer_interrupt,
+};
+
+static void __init ep93xx_timer_init(void)
+{
+	/* Enable periodic HZ timer.  */
+	__raw_writel(0x48, EP93XX_TIMER1_CONTROL);
+	__raw_writel((508000 / HZ) - 1, EP93XX_TIMER1_LOAD);
+	__raw_writel(0xc8, EP93XX_TIMER1_CONTROL);
+
+	/* Enable lost jiffy timer.  */
+	__raw_writel(0x100, EP93XX_TIMER4_VALUE_HIGH);
+
+	setup_irq(IRQ_EP93XX_TIMER1, &ep93xx_timer_irq);
+}
+
+static unsigned long ep93xx_gettimeoffset(void)
+{
+	int offset;
+
+	offset = __raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time;
+
+	/* Calculate (1000000 / 983040) * offset.  */
+	return offset + (53 * offset / 3072);
+}
+
+struct sys_timer ep93xx_timer = {
+	.init		= ep93xx_timer_init,
+	.offset		= ep93xx_gettimeoffset,
+};
+
+
+/*************************************************************************
+ * EP93xx IRQ handling
+ *************************************************************************/
+void __init ep93xx_init_irq(void)
+{
+	vic_init((void *)EP93XX_VIC1_BASE, 0, EP93XX_VIC1_VALID_IRQ_MASK);
+	vic_init((void *)EP93XX_VIC2_BASE, 32, EP93XX_VIC2_VALID_IRQ_MASK);
+}
+
+
+/*************************************************************************
+ * EP93xx peripheral handling
+ *************************************************************************/
+void __init ep93xx_init_devices(void)
+{
+	unsigned int v;
+
+	/*
+	 * Disallow access to MaverickCrunch initially.
+	 */
+	v = __raw_readl(EP93XX_SYSCON_DEVICE_CONFIG);
+	v &= ~EP93XX_SYSCON_DEVICE_CONFIG_CRUNCH_ENABLE;
+	__raw_writel(0xaa, EP93XX_SYSCON_SWLOCK);
+	__raw_writel(v, EP93XX_SYSCON_DEVICE_CONFIG);
+}