/*
   * Core driver for HTC PASIC3 LED/DS1WM chip.
   *
   * Copyright (C) 2006 Philipp Zabel <philipp.zabel@gmail.com>
   *
   * 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; version 2 of the License.
   */
  
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  
  #include <linux/gpio.h>
  #include <linux/io.h>
  #include <linux/irq.h>
  #include <linux/interrupt.h>
  #include <linux/mfd/core.h>
  #include <linux/mfd/ds1wm.h>
  #include <linux/mfd/htc-pasic3.h>
  #include <linux/slab.h>
  
  struct pasic3_data {
  	void __iomem *mapping;
  	unsigned int bus_shift;
  };
  
  #define REG_ADDR  5
  #define REG_DATA  6
  
  #define READ_MODE 0x80
  
  /*
   * write to a secondary register on the PASIC3
   */
  void pasic3_write_register(struct device *dev, u32 reg, u8 val)
  {
  	struct pasic3_data *asic = dev_get_drvdata(dev);
  	int bus_shift = asic->bus_shift;
  	void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
  	void __iomem *data = asic->mapping + (REG_DATA << bus_shift);
  
  	__raw_writeb(~READ_MODE & reg, addr);
  	__raw_writeb(val, data);
  }
  EXPORT_SYMBOL(pasic3_write_register); /* for leds-pasic3 */
  
  /*
   * read from a secondary register on the PASIC3
   */
  u8 pasic3_read_register(struct device *dev, u32 reg)
  {
  	struct pasic3_data *asic = dev_get_drvdata(dev);
  	int bus_shift = asic->bus_shift;
  	void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
  	void __iomem *data = asic->mapping + (REG_DATA << bus_shift);
  
  	__raw_writeb(READ_MODE | reg, addr);
  	return __raw_readb(data);
  }
  EXPORT_SYMBOL(pasic3_read_register); /* for leds-pasic3 */
  
  /*
   * LEDs
   */
  
  static struct mfd_cell led_cell __initdata = {
  	.name = "leds-pasic3",
  };
  
  /*
   * DS1WM
   */
  
  static int ds1wm_enable(struct platform_device *pdev)
  {
  	struct device *dev = pdev->dev.parent;
  	int c;
  
  	c = pasic3_read_register(dev, 0x28);
  	pasic3_write_register(dev, 0x28, c & 0x7f);
  
  	dev_dbg(dev, "DS1WM OWM_EN low (active) %02x
  ", c & 0x7f);
  	return 0;
  }
  
  static int ds1wm_disable(struct platform_device *pdev)
  {
  	struct device *dev = pdev->dev.parent;
  	int c;
  
  	c = pasic3_read_register(dev, 0x28);
  	pasic3_write_register(dev, 0x28, c | 0x80);
  
  	dev_dbg(dev, "DS1WM OWM_EN high (inactive) %02x
  ", c | 0x80);
  	return 0;
  }
  
  static struct ds1wm_driver_data ds1wm_pdata = {
  	.active_high = 0,
  	.reset_recover_delay = 1,
  };
  
  static struct resource ds1wm_resources[] __initdata = {
  	[0] = {
  		.start  = 0,
  		.flags  = IORESOURCE_MEM,
  	},
  	[1] = {
  		.start  = 0,
  		.end    = 0,
  		.flags  = IORESOURCE_IRQ,
  	},
  };
  
  static const struct mfd_cell ds1wm_cell __initconst = {
  	.name          = "ds1wm",
  	.enable        = ds1wm_enable,
  	.disable       = ds1wm_disable,
  	.platform_data = &ds1wm_pdata,
  	.pdata_size    = sizeof(ds1wm_pdata),
  	.num_resources = 2,
  	.resources     = ds1wm_resources,
  };
  
  static int __init pasic3_probe(struct platform_device *pdev)
  {
  	struct pasic3_platform_data *pdata = dev_get_platdata(&pdev->dev);
  	struct device *dev = &pdev->dev;
  	struct pasic3_data *asic;
  	struct resource *r;
  	int ret;
  	int irq = 0;
  
  	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
  	if (r) {
  		ds1wm_resources[1].flags = IORESOURCE_IRQ | (r->flags &
  			(IORESOURCE_IRQ_HIGHEDGE | IORESOURCE_IRQ_LOWEDGE));
  		irq = r->start;
  	}
  
  	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!r)
  		return -ENXIO;
  
  	if (!request_mem_region(r->start, resource_size(r), "pasic3"))
  		return -EBUSY;
  
  	asic = devm_kzalloc(dev, sizeof(struct pasic3_data), GFP_KERNEL);
  	if (!asic)
  		return -ENOMEM;
  
  	platform_set_drvdata(pdev, asic);
  
  	asic->mapping = ioremap(r->start, resource_size(r));
  	if (!asic->mapping) {
  		dev_err(dev, "couldn't ioremap PASIC3
  ");
  		return -ENOMEM;
  	}
  
  	/* calculate bus shift from mem resource */
  	asic->bus_shift = (resource_size(r) - 5) >> 3;
  
  	if (pdata && pdata->clock_rate) {
  		ds1wm_pdata.clock_rate = pdata->clock_rate;
  		/* the first 5 PASIC3 registers control the DS1WM */
  		ds1wm_resources[0].end = (5 << asic->bus_shift) - 1;
  		ret = mfd_add_devices(&pdev->dev, pdev->id,
  				      &ds1wm_cell, 1, r, irq, NULL);
  		if (ret < 0)
  			dev_warn(dev, "failed to register DS1WM
  ");
  	}
  
  	if (pdata && pdata->led_pdata) {
  		led_cell.platform_data = pdata->led_pdata;
  		led_cell.pdata_size = sizeof(struct pasic3_leds_machinfo);
  		ret = mfd_add_devices(&pdev->dev, pdev->id, &led_cell, 1, r,
  				      0, NULL);
  		if (ret < 0)
  			dev_warn(dev, "failed to register LED device
  ");
  	}
  
  	return 0;
  }
  
  static int pasic3_remove(struct platform_device *pdev)
  {
  	struct pasic3_data *asic = platform_get_drvdata(pdev);
  	struct resource *r;
  
  	mfd_remove_devices(&pdev->dev);
  
  	iounmap(asic->mapping);
  	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	release_mem_region(r->start, resource_size(r));
  	return 0;
  }
  
  MODULE_ALIAS("platform:pasic3");
  
  static struct platform_driver pasic3_driver = {
  	.driver		= {
  		.name	= "pasic3",
  	},
  	.remove		= pasic3_remove,
  };
  
  module_platform_driver_probe(pasic3_driver, pasic3_probe);
  
  MODULE_AUTHOR("Philipp Zabel <philipp.zabel@gmail.com>");
  MODULE_DESCRIPTION("Core driver for HTC PASIC3");
  MODULE_LICENSE("GPL");