/*
   *  lpc_sch.c - LPC interface for Intel Poulsbo SCH
   *
   *  LPC bridge function of the Intel SCH contains many other
   *  functional units, such as Interrupt controllers, Timers,
   *  Power Management, System Management, GPIO, RTC, and LPC
   *  Configuration Registers.
   *
   *  Copyright (c) 2010 CompuLab Ltd

   *  Copyright (c) 2014 Intel Corp.

   *  Author: Denis Turischev <denis@compulab.co.il>
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License 2 as published
   *  by the Free Software Foundation.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.

   */

  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/errno.h>
  #include <linux/acpi.h>
  #include <linux/pci.h>
  #include <linux/mfd/core.h>
  
  #define SMBASE		0x40
  #define SMBUS_IO_SIZE	64
  
  #define GPIOBASE	0x44
  #define GPIO_IO_SIZE	64

  #define GPIO_IO_SIZE_CENTERTON	128

  /* Intel Quark X1000 GPIO IRQ Number */
  #define GPIO_IRQ_QUARK_X1000	9

  #define WDTBASE		0x84
  #define WDT_IO_SIZE	64

  enum sch_chipsets {
  	LPC_SCH = 0,		/* Intel Poulsbo SCH */
  	LPC_ITC,		/* Intel Tunnel Creek */
  	LPC_CENTERTON,		/* Intel Centerton */

  	LPC_QUARK_X1000,	/* Intel Quark X1000 */

  };

  struct lpc_sch_info {
  	unsigned int io_size_smbus;
  	unsigned int io_size_gpio;
  	unsigned int io_size_wdt;

  	int irq_gpio;

  };

  static struct lpc_sch_info sch_chipset_info[] = {
  	[LPC_SCH] = {
  		.io_size_smbus = SMBUS_IO_SIZE,
  		.io_size_gpio = GPIO_IO_SIZE,

  		.irq_gpio = -1,

  	},
  	[LPC_ITC] = {
  		.io_size_smbus = SMBUS_IO_SIZE,
  		.io_size_gpio = GPIO_IO_SIZE,
  		.io_size_wdt = WDT_IO_SIZE,

  		.irq_gpio = -1,

  	},
  	[LPC_CENTERTON] = {
  		.io_size_smbus = SMBUS_IO_SIZE,
  		.io_size_gpio = GPIO_IO_SIZE_CENTERTON,
  		.io_size_wdt = WDT_IO_SIZE,

  		.irq_gpio = -1,
  	},
  	[LPC_QUARK_X1000] = {
  		.io_size_gpio = GPIO_IO_SIZE,
  		.irq_gpio = GPIO_IRQ_QUARK_X1000,

  	},

  };

  static const struct pci_device_id lpc_sch_ids[] = {

  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_SCH_LPC), LPC_SCH },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ITC_LPC), LPC_ITC },
  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CENTERTON_ILB), LPC_CENTERTON },

  	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_QUARK_X1000_ILB), LPC_QUARK_X1000 },

  	{ 0, }
  };
  MODULE_DEVICE_TABLE(pci, lpc_sch_ids);

  #define LPC_NO_RESOURCE		1
  #define LPC_SKIP_RESOURCE	2
  
  static int lpc_sch_get_io(struct pci_dev *pdev, int where, const char *name,
  			  struct resource *res, int size)

  {
  	unsigned int base_addr_cfg;
  	unsigned short base_addr;

  	if (size == 0)
  		return LPC_NO_RESOURCE;
  
  	pci_read_config_dword(pdev, where, &base_addr_cfg);

  	base_addr = 0;
  	if (!(base_addr_cfg & (1 << 31)))

  		dev_warn(&pdev->dev, "Decode of the %s I/O range disabled
  ",
  			 name);

  	else
  		base_addr = (unsigned short)base_addr_cfg;

  	if (base_addr == 0) {

  		dev_warn(&pdev->dev, "I/O space for %s uninitialized
  ", name);
  		return LPC_SKIP_RESOURCE;

  	}

  	res->start = base_addr;
  	res->end = base_addr + size - 1;
  	res->flags = IORESOURCE_IO;

  	return 0;
  }

  static int lpc_sch_populate_cell(struct pci_dev *pdev, int where,

  				 const char *name, int size, int irq,
  				 int id, struct mfd_cell *cell)

  {
  	struct resource *res;
  	int ret;

  	res = devm_kcalloc(&pdev->dev, 2, sizeof(*res), GFP_KERNEL);

  	if (!res)
  		return -ENOMEM;
  
  	ret = lpc_sch_get_io(pdev, where, name, res, size);
  	if (ret)
  		return ret;
  
  	memset(cell, 0, sizeof(*cell));
  
  	cell->name = name;
  	cell->resources = res;
  	cell->num_resources = 1;
  	cell->ignore_resource_conflicts = true;
  	cell->id = id;

  	/* Check if we need to add an IRQ resource */
  	if (irq < 0)
  		return 0;
  
  	res++;
  
  	res->start = irq;
  	res->end = irq;
  	res->flags = IORESOURCE_IRQ;
  
  	cell->num_resources++;

  	return 0;
  }
  
  static int lpc_sch_probe(struct pci_dev *dev, const struct pci_device_id *id)
  {
  	struct mfd_cell lpc_sch_cells[3];
  	struct lpc_sch_info *info = &sch_chipset_info[id->driver_data];
  	unsigned int cells = 0;
  	int ret;
  
  	ret = lpc_sch_populate_cell(dev, SMBASE, "isch_smbus",

  				    info->io_size_smbus, -1,

  				    id->device, &lpc_sch_cells[cells]);
  	if (ret < 0)
  		return ret;
  	if (ret == 0)
  		cells++;
  
  	ret = lpc_sch_populate_cell(dev, GPIOBASE, "sch_gpio",

  				    info->io_size_gpio, info->irq_gpio,

  				    id->device, &lpc_sch_cells[cells]);
  	if (ret < 0)
  		return ret;
  	if (ret == 0)
  		cells++;
  
  	ret = lpc_sch_populate_cell(dev, WDTBASE, "ie6xx_wdt",

  				    info->io_size_wdt, -1,

  				    id->device, &lpc_sch_cells[cells]);
  	if (ret < 0)
  		return ret;
  	if (ret == 0)
  		cells++;

  	if (cells == 0) {
  		dev_err(&dev->dev, "All decode registers disabled.
  ");
  		return -ENODEV;

  	}

  	return mfd_add_devices(&dev->dev, 0, lpc_sch_cells, cells, NULL, 0, NULL);

  }

  static void lpc_sch_remove(struct pci_dev *dev)

  {
  	mfd_remove_devices(&dev->dev);
  }
  
  static struct pci_driver lpc_sch_driver = {
  	.name		= "lpc_sch",
  	.id_table	= lpc_sch_ids,
  	.probe		= lpc_sch_probe,

  	.remove		= lpc_sch_remove,

  };

  module_pci_driver(lpc_sch_driver);

  
  MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>");
  MODULE_DESCRIPTION("LPC interface for Intel Poulsbo SCH");
  MODULE_LICENSE("GPL");