/*
 *  arch/ppc/kernel/feature.c
 *
 *  Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
 *
 *  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.
 *
 *  BenH: Changed implementation to work on multiple registers
 * 	  polarity is also taken into account. Removed delay (now
 * 	  responsibility of the caller). Added spinlocks.
 *
 */
#include <linux/config.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <asm/errno.h>
#include <asm/ohare.h>
#include <asm/heathrow.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/feature.h>

#undef DEBUG_FEATURE

#define MAX_FEATURE_CONTROLLERS		2
#define MAX_FEATURE_OFFSET		0x50
#define FREG(c,r)			(&(((c)->reg)[(r)>>2]))

typedef struct feature_bit {
	int		reg;		/* reg. offset from mac-io base */
	unsigned int	polarity;	/* 0 = normal, 1 = inverse */
	unsigned int	mask;		/* bit mask */
} fbit;

/* I don't have an OHare machine to test with, so I left those as they
 * were. Someone with such a machine chould check out what OF says and
 * try too see if they match the heathrow ones and should be changed too
 */
static fbit feature_bits_ohare_pbook[] = {
	{0x38,0,0},			/* FEATURE_null */
	{0x38,0,OH_SCC_RESET},		/* FEATURE_Serial_reset */
	{0x38,0,OH_SCC_ENABLE},		/* FEATURE_Serial_enable */
	{0x38,0,OH_SCCA_IO},		/* FEATURE_Serial_IO_A */
	{0x38,0,OH_SCCB_IO},		/* FEATURE_Serial_IO_B */
	{0x38,0,OH_FLOPPY_ENABLE},	/* FEATURE_SWIM3_enable */
	{0x38,0,OH_MESH_ENABLE},	/* FEATURE_MESH_enable */
	{0x38,0,OH_IDE0_ENABLE},	/* FEATURE_IDE0_enable */
	{0x38,1,OH_IDE0_RESET_N},	/* FEATURE_IDE0_reset */
	{0x38,0,OH_IOBUS_ENABLE},	/* FEATURE_IOBUS_enable */
	{0x38,1,OH_BAY_RESET_N},	/* FEATURE_Mediabay_reset */
	{0x38,1,OH_BAY_POWER_N},	/* FEATURE_Mediabay_power */
	{0x38,0,OH_BAY_PCI_ENABLE},	/* FEATURE_Mediabay_PCI_enable */
	{0x38,0,OH_BAY_IDE_ENABLE},	/* FEATURE_Mediabay_IDE_enable */
	{0x38,1,OH_IDE1_RESET_N},	/* FEATURE_Mediabay_IDE_reset */
	{0x38,0,OH_BAY_FLOPPY_ENABLE},	/* FEATURE_Mediabay_floppy_enable */
	{0x38,0,0},			/* FEATURE_BMac_reset */
	{0x38,0,0},			/* FEATURE_BMac_IO_enable */
	{0x38,0,0},			/* FEATURE_Modem_power */
	{0x38,0,0},			/* FEATURE_Slow_SCC_PCLK */
	{0x38,0,0},			/* FEATURE_Sound_Power */
	{0x38,0,0},			/* FEATURE_Sound_CLK_Enable */
	{0x38,0,0},			/* FEATURE_IDE2_enable */
	{0x38,0,0},			/* FEATURE_IDE2_reset */
};

/* Those bits are from a PowerBook. It's possible that desktop machines
 * based on heathrow need a different definition or some bits removed
 */
static fbit feature_bits_heathrow[] = {
	{0x38,0,0},			/* FEATURE_null */
	{0x38,0,HRW_RESET_SCC},		/* FEATURE_Serial_reset */
	{0x38,0,HRW_SCC_ENABLE},	/* FEATURE_Serial_enable */
	{0x38,0,HRW_SCCA_IO},		/* FEATURE_Serial_IO_A */
	{0x38,0,HRW_SCCB_IO},		/* FEATURE_Serial_IO_B */
	{0x38,0,HRW_SWIM_ENABLE},	/* FEATURE_SWIM3_enable */
	{0x38,0,HRW_MESH_ENABLE},	/* FEATURE_MESH_enable */
	{0x38,0,HRW_IDE0_ENABLE},	/* FEATURE_IDE0_enable */
	{0x38,1,HRW_IDE0_RESET_N},	/* FEATURE_IDE0_reset */
	{0x38,0,HRW_IOBUS_ENABLE},	/* FEATURE_IOBUS_enable */
	{0x38,1,HRW_BAY_RESET_N},	/* FEATURE_Mediabay_reset */
	{0x38,1,HRW_BAY_POWER_N},	/* FEATURE_Mediabay_power */
	{0x38,0,HRW_BAY_PCI_ENABLE},	/* FEATURE_Mediabay_PCI_enable */
	{0x38,0,HRW_BAY_IDE_ENABLE},	/* FEATURE_Mediabay_IDE_enable */
	{0x38,1,HRW_IDE1_RESET_N},	/* FEATURE_Mediabay_IDE_reset */
	{0x38,0,HRW_BAY_FLOPPY_ENABLE},	/* FEATURE_Mediabay_floppy_enable */
	{0x38,0,HRW_BMAC_RESET},	/* FEATURE_BMac_reset */
	{0x38,0,HRW_BMAC_IO_ENABLE},	/* FEATURE_BMac_IO_enable */
	{0x38,1,HRW_MODEM_POWER_N},	/* FEATURE_Modem_power */
	{0x38,0,HRW_SLOW_SCC_PCLK},	/* FEATURE_Slow_SCC_PCLK */
	{0x38,1,HRW_SOUND_POWER_N},	/* FEATURE_Sound_Power */
	{0x38,0,HRW_SOUND_CLK_ENABLE},	/* FEATURE_Sound_CLK_Enable */
	{0x38,0,0},			/* FEATURE_IDE2_enable */
	{0x38,0,0},			/* FEATURE_IDE2_reset */
};

/* Those bits are from an iBook.
 */
static fbit feature_bits_keylargo[] = {
	{0x38,0,0},			/* FEATURE_null */
	{0x38,0,0},			/* FEATURE_Serial_reset */
	{0x38,0,0x00000054},		/* FEATURE_Serial_enable */
	{0x38,0,0},			/* FEATURE_Serial_IO_A */
	{0x38,0,0},			/* FEATURE_Serial_IO_B */
	{0x38,0,0},			/* FEATURE_SWIM3_enable */
	{0x38,0,0},			/* FEATURE_MESH_enable */
	{0x38,0,0},			/* FEATURE_IDE0_enable */
	{0x3c,1,0x01000000},		/* FEATURE_IDE0_reset */
	{0x38,0,0},			/* FEATURE_IOBUS_enable */
	{0x38,0,0},			/* FEATURE_Mediabay_reset */
	{0x38,0,0},			/* FEATURE_Mediabay_power */
	{0x38,0,0},			/* FEATURE_Mediabay_PCI_enable */
	{0x38,0,0},			/* FEATURE_Mediabay_IDE_enable */
	{0x3c,1,0x08000000},		/* FEATURE_Mediabay_IDE_reset */
	{0x38,0,0},			/* FEATURE_Mediabay_floppy_enable */
	{0x38,0,0},			/* FEATURE_BMac_reset */
	{0x38,0,0},			/* FEATURE_BMac_IO_enable */
	{0x40,1,0x02000000},		/* FEATURE_Modem_power */
	{0x38,0,0},			/* FEATURE_Slow_SCC_PCLK */
	{0x38,0,0},			/* FEATURE_Sound_Power */
	{0x38,0,0},			/* FEATURE_Sound_CLK_Enable */
	{0x38,0,0},			/* FEATURE_IDE2_enable */
	{0x3c,1,0x40000000},		/* FEATURE_IDE2_reset */
};

/* definition of a feature controller object */
struct feature_controller {
	fbit*			bits;
	volatile u32*		reg;
	struct device_node*	device;
	spinlock_t		lock;
};

/* static functions */
static void
feature_add_controller(struct device_node *controller_device, fbit* bits);

static struct feature_controller*
feature_lookup_controller(struct device_node *device);

/* static varialbles */
static struct feature_controller	controllers[MAX_FEATURE_CONTROLLERS];
static int				controller_count = 0;


void
feature_init(void)
{
	struct device_node *np;

	if (_machine != _MACH_Pmac)
		return;

	np = find_devices("mac-io");
	while (np != NULL) {
		/* KeyLargo contains several (5 ?) FCR registers in mac-io,
		 * plus some gpio's which could eventually be handled here.
		 */
		if (device_is_compatible(np, "Keylargo")) {
			feature_add_controller(np, feature_bits_keylargo);
		} else {
			feature_add_controller(np, feature_bits_heathrow);
		}
		np = np->next;
	}
	if (controller_count == 0)
	{
		np = find_devices("ohare");
		if (np) {
			if (find_devices("via-pmu") != NULL)
				feature_add_controller(np, feature_bits_ohare_pbook);
			else
				/* else not sure; maybe this is a Starmax? */
				feature_add_controller(np, NULL);
		}
	}

	if (controller_count)
		printk(KERN_INFO "Registered %d feature controller(s)\n", controller_count);

#if defined(CONFIG_PMAC_PBOOK) && !defined(CONFIG_DMASOUND_AWACS)
	/* On PowerBooks, we disable the sound chip when dmasound is a module
	 * or not used at all
	 */
	if (controller_count && find_devices("via-pmu") != NULL) {
		feature_clear(controllers[0].device, FEATURE_Sound_power);
		feature_clear(controllers[0].device, FEATURE_Sound_CLK_enable);
	}
#endif
}

static void
feature_add_controller(struct device_node *controller_device, fbit* bits)
{
	struct feature_controller*	controller;
	
	if (controller_count >= MAX_FEATURE_CONTROLLERS) {
		printk(KERN_INFO "Feature controller %s skipped(MAX:%d)\n",
			controller_device->full_name, MAX_FEATURE_CONTROLLERS);
		return;
	}
	controller = &controllers[controller_count];

	controller->bits	= bits;
	controller->device	= controller_device;
	if (controller_device->n_addrs == 0) {
		printk(KERN_ERR "No addresses for %s\n",
			controller_device->full_name);
		return;
	}

	controller->reg		= (volatile u32 *)ioremap(
		controller_device->addrs[0].address, MAX_FEATURE_OFFSET);

	if (bits == NULL) {
		printk(KERN_INFO "Twiddling the magic ohare bits\n");
		out_le32(FREG(controller,OHARE_FEATURE_REG), STARMAX_FEATURES);
		return;
	}

	spin_lock_init(&controller->lock);

	controller_count++;
}

static struct feature_controller*
feature_lookup_controller(struct device_node *device)
{
	int	i;
	
	if (device == NULL)
		return NULL;
		
	while(device)
	{
		for (i=0; i<controller_count; i++)
			if (device == controllers[i].device)
				return &controllers[i];
		device = device->parent;
	}

#ifdef DEBUG_FEATURE
	printk("feature: <%s> not found on any controller\n",
		device->name);
#endif
	
	return NULL;
}

int
feature_set(struct device_node* device, enum system_feature f)
{
	struct feature_controller*	controller;
	unsigned long			flags;
	unsigned long			value;
	fbit*				bit;

	if (f >= FEATURE_last)
		return -EINVAL;	

	controller = feature_lookup_controller(device);
	if (!controller)
		return -ENODEV;
	bit = &controller->bits[f];
	
#ifdef DEBUG_FEATURE
	printk("feature: <%s> setting feature %d in controller @0x%x\n",
		device->name, (int)f, (unsigned int)controller->reg);
#endif

	spin_lock_irqsave(&controller->lock, flags);
	value = in_le32(FREG(controller, bit->reg));
	value = bit->polarity ? (value & ~bit->mask) : (value | bit->mask);
	out_le32(FREG(controller, bit->reg), value);
	(void)in_le32(FREG(controller, bit->reg));
	spin_unlock_irqrestore(&controller->lock, flags);
	
	return 0;
}

int
feature_clear(struct device_node* device, enum system_feature f)
{
	struct feature_controller*	controller;
	unsigned long			flags;
	unsigned long			value;
	fbit*				bit;

	if (f >= FEATURE_last)
		return -EINVAL;	

	controller = feature_lookup_controller(device);
	if (!controller)
		return -ENODEV;
	bit = &controller->bits[f];
	
#ifdef DEBUG_FEATURE
	printk("feature: <%s> clearing feature %d in controller @0x%x\n",
		device->name, (int)f, (unsigned int)controller->reg);
#endif

	spin_lock_irqsave(&controller->lock, flags);
	value = in_le32(FREG(controller, bit->reg));
	value = bit->polarity ? (value | bit->mask) : (value & ~bit->mask);
	out_le32(FREG(controller, bit->reg), value);
	(void)in_le32(FREG(controller, bit->reg));
	spin_unlock_irqrestore(&controller->lock, flags);
	
	return 0;
}

int
feature_test(struct device_node* device, enum system_feature f)
{
	struct feature_controller*	controller;
	unsigned long			value;
	fbit*				bit;

	if (f >= FEATURE_last)
		return -EINVAL;	

	controller = feature_lookup_controller(device);
	if (!controller)
		return -ENODEV;
	bit = &controller->bits[f];
	
#ifdef DEBUG_FEATURE
	printk("feature: <%s> clearing feature %d in controller @0x%x\n",
		device->name, (int)f, (unsigned int)controller->reg);
#endif
	/* If one feature contains several bits, all of them must be set
	 * for value to be true, or all of them must be 0 if polarity is
	 * inverse
	 */
	value = (in_le32(FREG(controller, bit->reg)) & bit->mask);
	return bit->polarity ? (value == 0) : (value == bit->mask);
}