/*
 * ARC PGU DRM driver.
 *
 * Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 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/clk.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_cma_helper.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_atomic_helper.h>
#include <linux/of_reserved_mem.h>

#include "arcpgu.h"
#include "arcpgu_regs.h"

static void arcpgu_fb_output_poll_changed(struct drm_device *dev)
{
        struct arcpgu_drm_private *arcpgu = dev->dev_private;

        drm_fbdev_cma_hotplug_event(arcpgu->fbdev);
}

static const struct drm_mode_config_funcs arcpgu_drm_modecfg_funcs = {
        .fb_create  = drm_gem_fb_create,
        .output_poll_changed = arcpgu_fb_output_poll_changed,
        .atomic_check = drm_atomic_helper_check,
        .atomic_commit = drm_atomic_helper_commit,
};

static void arcpgu_setup_mode_config(struct drm_device *drm)
{
        drm_mode_config_init(drm);
        drm->mode_config.min_width = 0;
        drm->mode_config.min_height = 0;
        drm->mode_config.max_width = 1920;
        drm->mode_config.max_height = 1080;
        drm->mode_config.funcs = &arcpgu_drm_modecfg_funcs;
}

DEFINE_DRM_GEM_CMA_FOPS(arcpgu_drm_ops);

static void arcpgu_lastclose(struct drm_device *drm)
{
        struct arcpgu_drm_private *arcpgu = drm->dev_private;

        drm_fbdev_cma_restore_mode(arcpgu->fbdev);
}

static int arcpgu_load(struct drm_device *drm)
{
        struct platform_device *pdev = to_platform_device(drm->dev);
        struct arcpgu_drm_private *arcpgu;
        struct device_node *encoder_node;
        struct resource *res;
        int ret;

        arcpgu = devm_kzalloc(&pdev->dev, sizeof(*arcpgu), GFP_KERNEL);
        if (arcpgu == NULL)
                return -ENOMEM;

        drm->dev_private = arcpgu;

        arcpgu->clk = devm_clk_get(drm->dev, "pxlclk");
        if (IS_ERR(arcpgu->clk))
                return PTR_ERR(arcpgu->clk);

        arcpgu_setup_mode_config(drm);

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        arcpgu->regs = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(arcpgu->regs))
                return PTR_ERR(arcpgu->regs);

        dev_info(drm->dev, "arc_pgu ID: 0x%x\n",
                 arc_pgu_read(arcpgu, ARCPGU_REG_ID));

        /* Get the optional framebuffer memory resource */
        ret = of_reserved_mem_device_init(drm->dev);
        if (ret && ret != -ENODEV)
                return ret;

        if (dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)))
                return -ENODEV;

        if (arc_pgu_setup_crtc(drm) < 0)
                return -ENODEV;

        /* find the encoder node and initialize it */
        encoder_node = of_parse_phandle(drm->dev->of_node, "encoder-slave", 0);
        if (encoder_node) {
                ret = arcpgu_drm_hdmi_init(drm, encoder_node);
                of_node_put(encoder_node);
                if (ret < 0)
                        return ret;
        } else {
                ret = arcpgu_drm_sim_init(drm, NULL);
                if (ret < 0)
                        return ret;
        }

        drm_mode_config_reset(drm);
        drm_kms_helper_poll_init(drm);

        arcpgu->fbdev = drm_fbdev_cma_init(drm, 16,
                                           drm->mode_config.num_connector);
        if (IS_ERR(arcpgu->fbdev)) {
                ret = PTR_ERR(arcpgu->fbdev);
                arcpgu->fbdev = NULL;
                return -ENODEV;
        }

        platform_set_drvdata(pdev, drm);
        return 0;
}

static int arcpgu_unload(struct drm_device *drm)
{
        struct arcpgu_drm_private *arcpgu = drm->dev_private;

        if (arcpgu->fbdev) {
                drm_fbdev_cma_fini(arcpgu->fbdev);
                arcpgu->fbdev = NULL;
        }
        drm_kms_helper_poll_fini(drm);
        drm_mode_config_cleanup(drm);

        return 0;
}

#ifdef CONFIG_DEBUG_FS
static int arcpgu_show_pxlclock(struct seq_file *m, void *arg)
{
        struct drm_info_node *node = (struct drm_info_node *)m->private;
        struct drm_device *drm = node->minor->dev;
        struct arcpgu_drm_private *arcpgu = drm->dev_private;
        unsigned long clkrate = clk_get_rate(arcpgu->clk);
        unsigned long mode_clock = arcpgu->crtc.mode.crtc_clock * 1000;

        seq_printf(m, "hw  : %lu\n", clkrate);
        seq_printf(m, "mode: %lu\n", mode_clock);
        return 0;
}

static struct drm_info_list arcpgu_debugfs_list[] = {
        { "clocks", arcpgu_show_pxlclock, 0 },
};

static int arcpgu_debugfs_init(struct drm_minor *minor)
{
        return drm_debugfs_create_files(arcpgu_debugfs_list,
                ARRAY_SIZE(arcpgu_debugfs_list), minor->debugfs_root, minor);
}
#endif

static struct drm_driver arcpgu_drm_driver = {
        .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME |
                           DRIVER_ATOMIC,
        .lastclose = arcpgu_lastclose,
        .name = "arcpgu",
        .desc = "ARC PGU Controller",
        .date = "20160219",
        .major = 1,
        .minor = 0,
        .patchlevel = 0,
        .fops = &arcpgu_drm_ops,
        .dumb_create = drm_gem_cma_dumb_create,
        .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
        .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
        .gem_free_object_unlocked = drm_gem_cma_free_object,
        .gem_print_info = drm_gem_cma_print_info,
        .gem_vm_ops = &drm_gem_cma_vm_ops,
        .gem_prime_export = drm_gem_prime_export,
        .gem_prime_import = drm_gem_prime_import,
        .gem_prime_get_sg_table = drm_gem_cma_prime_get_sg_table,
        .gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
        .gem_prime_vmap = drm_gem_cma_prime_vmap,
        .gem_prime_vunmap = drm_gem_cma_prime_vunmap,
        .gem_prime_mmap = drm_gem_cma_prime_mmap,
#ifdef CONFIG_DEBUG_FS
        .debugfs_init = arcpgu_debugfs_init,
#endif
};

static int arcpgu_probe(struct platform_device *pdev)
{
        struct drm_device *drm;
        int ret;

        drm = drm_dev_alloc(&arcpgu_drm_driver, &pdev->dev);
        if (IS_ERR(drm))
                return PTR_ERR(drm);

        ret = arcpgu_load(drm);
        if (ret)
                goto err_unref;

        ret = drm_dev_register(drm, 0);
        if (ret)
                goto err_unload;

        return 0;

err_unload:
        arcpgu_unload(drm);

err_unref:
        drm_dev_unref(drm);

        return ret;
}

static int arcpgu_remove(struct platform_device *pdev)
{
        struct drm_device *drm = platform_get_drvdata(pdev);

        drm_dev_unregister(drm);
        arcpgu_unload(drm);
        drm_dev_unref(drm);

        return 0;
}

static const struct of_device_id arcpgu_of_table[] = {
        {.compatible = "snps,arcpgu"},
        {}
};

MODULE_DEVICE_TABLE(of, arcpgu_of_table);

static struct platform_driver arcpgu_platform_driver = {
        .probe = arcpgu_probe,
        .remove = arcpgu_remove,
        .driver = {
                   .name = "arcpgu",
                   .of_match_table = arcpgu_of_table,
                   },
};

module_platform_driver(arcpgu_platform_driver);

MODULE_AUTHOR("Carlos Palminha <palminha@synopsys.com>");
MODULE_DESCRIPTION("ARC PGU DRM driver");
MODULE_LICENSE("GPL");