/*
   * 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 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 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 !
  ",
  		       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
  ", 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
  ", __func__, board_rev);
  	iounmap(fpga);
  	return 0;
  
  fail:
  	pr_info("%s: Unable to find board revision
  ", __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
  ", __func__, dev->irq);
  		} else if (board_rev == 2) {
  			dev->irq = irq_create_mapping(NULL, 49);
  			pr_info("%s: Mapping irq %d
  ", __func__, dev->irq);
  		} else {
  			pr_alert("%s: Unknown board revision
  ", __func__);
  		}
  	}
  }
  
  /*
   * Called very early, MMU is off, device-tree isn't unflattened
   */
  static int __init ppc47x_probe(void)
  {
  	unsigned long root = of_get_flat_dt_root();
  
  	if (of_flat_dt_is_compatible(root, "ibm,akebono"))
  		return 1;
  
  	if (of_flat_dt_is_compatible(root, "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,
  };