path: root/arch/arm/mach-pxa/viper.c

/*
 *  linux/arch/arm/mach-pxa/viper.c
 *
 *  Support for the Arcom VIPER SBC.
 *
 *  Author:	Ian Campbell
 *  Created:    Feb 03, 2003
 *  Copyright:  Arcom Control Systems
 *
 *  Maintained by Marc Zyngier <maz@misterjones.org>
 *                             <marc.zyngier@altran.com>
 *
 * Based on lubbock.c:
 *  Author:	Nicolas Pitre
 *  Created:	Jun 15, 2001
 *  Copyright:	MontaVista Software Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */

#include <linux/types.h>
#include <linux/memory.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/major.h>
#include <linux/module.h>
#include <linux/pm.h>
#include <linux/sched.h>
#include <linux/gpio.h>
#include <linux/jiffies.h>
#include <linux/i2c-gpio.h>
#include <linux/i2c/pxa-i2c.h>
#include <linux/serial_8250.h>
#include <linux/smc91x.h>
#include <linux/pwm_backlight.h>
#include <linux/usb/isp116x.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/physmap.h>
#include <linux/syscore_ops.h>

#include <mach/pxa25x.h>
#include <mach/audio.h>
#include <mach/pxafb.h>
#include <mach/regs-uart.h>
#include <mach/arcom-pcmcia.h>
#include <mach/viper.h>

#include <asm/setup.h>
#include <asm/mach-types.h>
#include <asm/irq.h>
#include <asm/sizes.h>

#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/mach/irq.h>

#include "generic.h"
#include "devices.h"

static unsigned int icr;

static void viper_icr_set_bit(unsigned int bit)
{
	icr |= bit;
	VIPER_ICR = icr;
}

static void viper_icr_clear_bit(unsigned int bit)
{
	icr &= ~bit;
	VIPER_ICR = icr;
}

/* This function is used from the pcmcia module to reset the CF */
static void viper_cf_reset(int state)
{
	if (state)
		viper_icr_set_bit(VIPER_ICR_CF_RST);
	else
		viper_icr_clear_bit(VIPER_ICR_CF_RST);
}

static struct arcom_pcmcia_pdata viper_pcmcia_info = {
	.cd_gpio	= VIPER_CF_CD_GPIO,
	.rdy_gpio	= VIPER_CF_RDY_GPIO,
	.pwr_gpio	= VIPER_CF_POWER_GPIO,
	.reset		= viper_cf_reset,
};

static struct platform_device viper_pcmcia_device = {
	.name		= "viper-pcmcia",
	.id		= -1,
	.dev		= {
		.platform_data	= &viper_pcmcia_info,
	},
};

/*
 * The CPLD version register was not present on VIPER boards prior to
 * v2i1. On v1 boards where the version register is not present we
 * will just read back the previous value from the databus.
 *
 * Therefore we do two reads. The first time we write 0 to the
 * (read-only) register before reading and the second time we write
 * 0xff first. If the two reads do not match or they read back as 0xff
 * or 0x00 then we have version 1 hardware.
 */
static u8 viper_hw_version(void)
{
	u8 v1, v2;
	unsigned long flags;

	local_irq_save(flags);

	VIPER_VERSION = 0;
	v1 = VIPER_VERSION;
	VIPER_VERSION = 0xff;
	v2 = VIPER_VERSION;

	v1 = (v1 != v2 || v1 == 0xff) ? 0 : v1;

	local_irq_restore(flags);
	return v1;
}

/* CPU system core operations. */
static int viper_cpu_suspend(void)
{
	viper_icr_set_bit(VIPER_ICR_R_DIS);
	return 0;
}

static void viper_cpu_resume(void)
{
	viper_icr_clear_bit(VIPER_ICR_R_DIS);
}

static struct syscore_ops viper_cpu_syscore_ops = {
	.suspend	= viper_cpu_suspend,
	.resume		= viper_cpu_resume,
};

static unsigned int current_voltage_divisor;

/*
 * If force is not true then step from existing to new divisor. If
 * force is true then jump straight to the new divisor. Stepping is
 * used because if the jump in voltage is too large, the VCC can dip
 * too low and the regulator cuts out.
 *
 * force can be used to initialize the divisor to a know state by
 * setting the value for the current clock speed, since we are already
 * running at that speed we know the voltage should be pretty close so
 * the jump won't be too large
 */
static void viper_set_core_cpu_voltage(unsigned long khz, int force)
{
	int i = 0;
	unsigned int divisor = 0;
	const char *v;

	if (khz < 200000) {
		v = "1.0"; divisor = 0xfff;
	} else if (khz < 300000) {
		v = "1.1"; divisor = 0xde5;
	} else {
		v = "1.3"; divisor = 0x325;
	}

	pr_debug("viper: setting CPU core voltage to %sV at %d.%03dMHz\n",
		 v, (int)khz / 1000, (int)khz % 1000);

#define STEP 0x100
	do {
		int step;

		if (force)
			step = divisor;
		else if (current_voltage_divisor < divisor - STEP)
			step = current_voltage_divisor + STEP;
		else if (current_voltage_divisor > divisor + STEP)
			step = current_voltage_divisor - STEP;
		else
			step = divisor;
		force = 0;

		gpio_set_value(VIPER_PSU_CLK_GPIO, 0);