/*
 * 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\n",
                 (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\n",
                 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\n");
                return irq;
        }

        /* Private driver data */
        priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                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\n");

        /* 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\n");
        /*
         * 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\n");
                        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\n",
                        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");