/*
   * ImgTec IR Decoder found in PowerDown Controller.
   *
   * Copyright 2010-2014 Imagination Technologies Ltd.
   *
   * 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.
   *
   * This contains core img-ir code for setting up the driver. The two interfaces
   * (raw and hardware decode) are handled separately.
   */
  
  #include <linux/clk.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/io.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/slab.h>
  #include <linux/spinlock.h>
  #include "img-ir.h"
  
  static irqreturn_t img_ir_isr(int irq, void *dev_id)
  {
  	struct img_ir_priv *priv = dev_id;
  	u32 irq_status;
  
  	spin_lock(&priv->lock);
  	/* we have to clear irqs before reading */
  	irq_status = img_ir_read(priv, IMG_IR_IRQ_STATUS);
  	img_ir_write(priv, IMG_IR_IRQ_CLEAR, irq_status);
  
  	/* don't handle valid data irqs if we're only interested in matches */
  	irq_status &= img_ir_read(priv, IMG_IR_IRQ_ENABLE);
  
  	/* hand off edge interrupts to raw decode handler */
  	if (irq_status & IMG_IR_IRQ_EDGE && img_ir_raw_enabled(&priv->raw))
  		img_ir_isr_raw(priv, irq_status);
  
  	/* hand off hardware match interrupts to hardware decode handler */
  	if (irq_status & (IMG_IR_IRQ_DATA_MATCH |
  			  IMG_IR_IRQ_DATA_VALID |
  			  IMG_IR_IRQ_DATA2_VALID) &&
  	    img_ir_hw_enabled(&priv->hw))
  		img_ir_isr_hw(priv, irq_status);
  
  	spin_unlock(&priv->lock);
  	return IRQ_HANDLED;
  }
  
  static void img_ir_setup(struct img_ir_priv *priv)
  {
  	/* start off with interrupts disabled */
  	img_ir_write(priv, IMG_IR_IRQ_ENABLE, 0);
  
  	img_ir_setup_raw(priv);
  	img_ir_setup_hw(priv);
  
  	if (!IS_ERR(priv->clk))
  		clk_prepare_enable(priv->clk);
  }
  
  static void img_ir_ident(struct img_ir_priv *priv)
  {
  	u32 core_rev = img_ir_read(priv, IMG_IR_CORE_REV);
  
  	dev_info(priv->dev,
  		 "IMG IR Decoder (%d.%d.%d.%d) probed successfully
  ",
  		 (core_rev & IMG_IR_DESIGNER) >> IMG_IR_DESIGNER_SHIFT,
  		 (core_rev & IMG_IR_MAJOR_REV) >> IMG_IR_MAJOR_REV_SHIFT,
  		 (core_rev & IMG_IR_MINOR_REV) >> IMG_IR_MINOR_REV_SHIFT,
  		 (core_rev & IMG_IR_MAINT_REV) >> IMG_IR_MAINT_REV_SHIFT);
  	dev_info(priv->dev, "Modes:%s%s
  ",
  		 img_ir_hw_enabled(&priv->hw) ? " hardware" : "",
  		 img_ir_raw_enabled(&priv->raw) ? " raw" : "");
  }
  
  static int img_ir_probe(struct platform_device *pdev)
  {
  	struct img_ir_priv *priv;
  	struct resource *res_regs;
  	int irq, error, error2;
  
  	/* Get resources from platform device */
  	irq = platform_get_irq(pdev, 0);
  	if (irq < 0) {
  		dev_err(&pdev->dev, "cannot find IRQ resource
  ");
  		return irq;
  	}
  
  	/* Private driver data */
  	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
  	if (!priv) {
  		dev_err(&pdev->dev, "cannot allocate device data
  ");
  		return -ENOMEM;
  	}
  	platform_set_drvdata(pdev, priv);
  	priv->dev = &pdev->dev;
  	spin_lock_init(&priv->lock);
  
  	/* Ioremap the registers */
  	res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	priv->reg_base = devm_ioremap_resource(&pdev->dev, res_regs);
  	if (IS_ERR(priv->reg_base))
  		return PTR_ERR(priv->reg_base);
  
  	/* Get core clock */
  	priv->clk = devm_clk_get(&pdev->dev, "core");
  	if (IS_ERR(priv->clk))
  		dev_warn(&pdev->dev, "cannot get core clock resource
  ");
  
  	/* Get sys clock */
  	priv->sys_clk = devm_clk_get(&pdev->dev, "sys");
  	if (IS_ERR(priv->sys_clk))
  		dev_warn(&pdev->dev, "cannot get sys clock resource
  ");
  	/*
  	 * Enabling the system clock before the register interface is
  	 * accessed. ISR shouldn't get called with Sys Clock disabled,
  	 * hence exiting probe with an error.
  	 */
  	if (!IS_ERR(priv->sys_clk)) {
  		error = clk_prepare_enable(priv->sys_clk);
  		if (error) {
  			dev_err(&pdev->dev, "cannot enable sys clock
  ");
  			return error;
  		}
  	}
  
  	/* Set up raw & hw decoder */
  	error = img_ir_probe_raw(priv);
  	error2 = img_ir_probe_hw(priv);
  	if (error && error2) {
  		if (error == -ENODEV)
  			error = error2;
  		goto err_probe;
  	}
  
  	/* Get the IRQ */
  	priv->irq = irq;
  	error = request_irq(priv->irq, img_ir_isr, 0, "img-ir", priv);
  	if (error) {
  		dev_err(&pdev->dev, "cannot register IRQ %u
  ",
  			priv->irq);
  		error = -EIO;
  		goto err_irq;
  	}
  
  	img_ir_ident(priv);
  	img_ir_setup(priv);
  
  	return 0;
  
  err_irq:
  	img_ir_remove_hw(priv);
  	img_ir_remove_raw(priv);
  err_probe:
  	if (!IS_ERR(priv->sys_clk))
  		clk_disable_unprepare(priv->sys_clk);
  	return error;
  }
  
  static int img_ir_remove(struct platform_device *pdev)
  {
  	struct img_ir_priv *priv = platform_get_drvdata(pdev);
  
  	free_irq(priv->irq, priv);
  	img_ir_remove_hw(priv);
  	img_ir_remove_raw(priv);
  
  	if (!IS_ERR(priv->clk))
  		clk_disable_unprepare(priv->clk);
  	if (!IS_ERR(priv->sys_clk))
  		clk_disable_unprepare(priv->sys_clk);
  	return 0;
  }
  
  static SIMPLE_DEV_PM_OPS(img_ir_pmops, img_ir_suspend, img_ir_resume);
  
  static const struct of_device_id img_ir_match[] = {
  	{ .compatible = "img,ir-rev1" },
  	{}
  };
  MODULE_DEVICE_TABLE(of, img_ir_match);
  
  static struct platform_driver img_ir_driver = {
  	.driver = {
  		.name = "img-ir",
  		.of_match_table	= img_ir_match,
  		.pm = &img_ir_pmops,
  	},
  	.probe = img_ir_probe,
  	.remove = img_ir_remove,
  };
  
  module_platform_driver(img_ir_driver);
  
  MODULE_AUTHOR("Imagination Technologies Ltd.");
  MODULE_DESCRIPTION("ImgTec IR");
  MODULE_LICENSE("GPL");