/*
 * PowerPC 476FPE board specific routines
 *
 * Copyright © 2013 Tony Breeds IBM Corporation
 * Copyright © 2013 Alistair Popple IBM Corporation
 *
 * Based on earlier code:
 *    Matt Porter <mporter@kernel.crashing.org>
 *    Copyright 2002-2005 MontaVista Software Inc.
 *
 *    Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
 *    Copyright (c) 2003-2005 Zultys Technologies
 *
 *    Rewritten and ported to the merged powerpc tree:
 *    Copyright 2007 David Gibson <dwg@au1.ibm.com>, IBM Corporation.
 *    Copyright © 2011 David Kliekamp IBM Corporation
 *
 * 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/init.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/rtc.h>

#include <asm/machdep.h>
#include <asm/prom.h>
#include <asm/udbg.h>
#include <asm/time.h>
#include <asm/uic.h>
#include <asm/ppc4xx.h>
#include <asm/mpic.h>
#include <asm/mmu.h>

#include <linux/pci.h>
#include <linux/i2c.h>

static const struct of_device_id ppc47x_of_bus[] __initconst = {
	{ .compatible = "ibm,plb4", },
	{ .compatible = "ibm,plb6", },
	{ .compatible = "ibm,opb", },
	{ .compatible = "ibm,ebc", },
	{},
};

/* The EEPROM is missing and the default values are bogus.  This forces USB in
 * to EHCI mode */
static void quirk_ppc_currituck_usb_fixup(struct pci_dev *dev)
{
	if (of_machine_is_compatible("ibm,currituck")) {
		pci_write_config_dword(dev, 0xe0, 0x0114231f);
		pci_write_config_dword(dev, 0xe4, 0x00006c40);
	}
}
DECLARE_PCI_FIXUP_HEADER(0x1033, 0x0035, quirk_ppc_currituck_usb_fixup);

/* Akebono has an AVR microcontroller attached to the I2C bus
 * which is used to power off/reset the system. */

/* AVR I2C Commands */
#define AVR_PWRCTL_CMD (0x26)

/* Flags for the power control I2C commands */
#define AVR_PWRCTL_PWROFF (0x01)
#define AVR_PWRCTL_RESET (0x02)

static struct i2c_client *avr_i2c_client;
static void __noreturn avr_halt_system(int pwrctl_flags)
{
	/* Request the AVR to reset the system */
	i2c_smbus_write_byte_data(avr_i2c_client,
				  AVR_PWRCTL_CMD, pwrctl_flags);

	/* Wait for system to be reset */
	while (1)
		;
}

static void avr_power_off_system(void)
{
	avr_halt_system(AVR_PWRCTL_PWROFF);
}

static void __noreturn avr_reset_system(char *cmd)
{
	avr_halt_system(AVR_PWRCTL_RESET);
}

static int avr_probe(struct i2c_client *client,
			    const struct i2c_device_id *id)
{
	avr_i2c_client = client;
	ppc_md.restart = avr_reset_system;
	pm_power_off = avr_power_off_system;
	return 0;
}

static const struct i2c_device_id avr_id[] = {
	{ "akebono-avr", 0 },
	{ }
};

static struct i2c_driver avr_driver = {
	.driver = {
		.name = "akebono-avr",
	},
	.probe = avr_probe,
	.id_table = avr_id,
};

static int __init ppc47x_device_probe(void)
{
	i2c_add_driver(&avr_driver);
	of_platform_bus_probe(NULL, ppc47x_of_bus, NULL);

	return 0;
}
machine_device_initcall(ppc47x, ppc47x_device_probe);

static void __init ppc47x_init_irq(void)
{
	struct device_node *np;

	/* Find top level interrupt controller */
	for_each_node_with_property(np, "interrupt-controller") {
		if (of_get_property(np, "interrupts", NULL) == NULL)
			break;
	}
	if (np == NULL)
		panic("Can't find top level interrupt controller");

	/* Check type and do appropriate initialization */
	if (of_device_is_compatible(np, "chrp,open-pic")) {
		/* The MPIC driver will get everything it needs from the
		 * device-tree, just pass 0 to all arguments
		 */
		struct mpic *mpic =
			mpic_alloc(np, 0, MPIC_NO_RESET, 0, 0, " MPIC     ");
		BUG_ON(mpic == NULL);
		mpic_init(mpic);
		ppc_md.get_irq = mpic_get_irq;
	} else
		panic("Unrecognized top level interrupt controller");
}

#ifdef CONFIG_SMP
static void smp_ppc47x_setup_cpu(int cpu)
{
	mpic_setup_this_cpu();
}

static int smp_ppc47x_kick_cpu(int cpu)
{
	struct device_node *cpunode = of_get_cpu_node(cpu, NULL);
	const u64 *spin_table_addr_prop;
	u32 *spin_table;
	extern void start_secondary_47x(void);

	BUG_ON(cpunode == NULL);

	/* Assume spin table. We could test for the enable-method in
	 * the device-tree but currently there's little point as it's
	 * our only supported method
	 */
	spin_table_addr_prop =
		of_get_property(cpunode, "cpu-release-addr", NULL);

	if (spin_table_addr_prop == NULL) {
		pr_err("CPU%d: Can't start, missing cpu-release-addr !\n",
		       cpu);
		return 1;
	}

	/* Assume it's mapped as part of the linear mapping. This is a bit
	 * fishy but will work fine for now
	 *
	 * XXX: Is there any reason to assume differently?
	 */
	spin_table = (u32 *)__va(*spin_table_addr_prop);
	pr_debug("CPU%d: Spin table mapped at %p\n", cpu, spin_table);

	spin_table[3] = cpu;
	smp_wmb();
	spin_table[1] = __pa(start_secondary_47x);
	mb();

	return 0;
}

static struct smp_ops_t ppc47x_smp_ops = {
	.probe		= smp_mpic_probe,
	.message_pass	= smp_mpic_message_pass,
	.setup_cpu	= smp_ppc47x_setup_cpu,
	.kick_cpu	= smp_ppc47x_kick_cpu,
	.give_timebase	= smp_generic_give_timebase,
	.take_timebase	= smp_generic_take_timebase,
};

static void __init ppc47x_smp_init(void)
{
	if (mmu_has_feature(MMU_FTR_TYPE_47x))
		smp_ops = &ppc47x_smp_ops;
}

#else /* CONFIG_SMP */
static void __init ppc47x_smp_init(void) { }
#endif /* CONFIG_SMP */

static void __init ppc47x_setup_arch(void)
{

	/* No need to check the DMA config as we /know/ our windows are all of
	 * RAM.  Lets hope that doesn't change */
	swiotlb_detect_4g();

	ppc47x_smp_init();
}

static int board_rev = -1;
static int __init ppc47x_get_board_rev(void)
{
	int reg;
	u8 *fpga;
	struct device_node *np = NULL;

	if (of_machine_is_compatible("ibm,currituck")) {
		np = of_find_compatible_node(NULL, NULL, "ibm,currituck-fpga");
		reg = 0;
	} else if (of_machine_is_compatible("ibm,akebono")) {
		np = of_find_compatible_node(NULL, NULL, "ibm,akebono-fpga");
		reg = 2;
	}

	if (!np)
		goto fail;

	fpga = (u8 *) of_iomap(np, 0);
	of_node_put(np);
	if (!fpga)
		goto fail;

	board_rev = ioread8(fpga + reg) & 0x03;
	pr_info("%s: Found board revision %d\n", __func__, board_rev);
	iounmap(fpga);
	return 0;

fail:
	pr_info("%s: Unable to find board revision\n", __func__);
	return 0;
}
machine_arch_initcall(ppc47x, ppc47x_get_board_rev);

/* Use USB controller should have been hardware swizzled but it wasn't :( */
static void ppc47x_pci_irq_fixup(struct pci_dev *dev)
{
	if (dev->vendor == 0x1033 && (dev->device == 0x0035 ||
				      dev->device == 0x00e0)) {
		if (board_rev == 0) {
			dev->irq = irq_create_mapping(NULL, 47);
			pr_info("%s: Mapping irq %d\n", __func__, dev->irq);
		} else if (board_rev == 2) {
			dev->irq = irq_create_mapping(NULL, 49);
			pr_info("%s: Mapping irq %d\n", __func__, dev->irq);
		} else {
			pr_alert("%s: Unknown board revision\n", __func__);
		}
	}
}

/*
 * Called very early, MMU is off, device-tree isn't unflattened
 */
static int __init ppc47x_probe(void)
{
	if (of_machine_is_compatible("ibm,akebono"))
		return 1;

	if (of_machine_is_compatible("ibm,currituck")) {
		ppc_md.pci_irq_fixup = ppc47x_pci_irq_fixup;
		return 1;
	}

	return 0;
}

define_machine(ppc47x) {
	.name			= "PowerPC 47x",
	.probe			= ppc47x_probe,
	.progress		= udbg_progress,
	.init_IRQ		= ppc47x_init_irq,
	.setup_arch		= ppc47x_setup_arch,
	.restart		= ppc4xx_reset_system,
	.calibrate_decr		= generic_calibrate_decr,
};