root/drivers/gpu/drm/logicvc/logicvc_drm.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2019-2022 Bootlin
 * Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/types.h>

#include <drm/clients/drm_client_setup.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fbdev_dma.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_print.h>

#include "logicvc_crtc.h"
#include "logicvc_drm.h"
#include "logicvc_interface.h"
#include "logicvc_mode.h"
#include "logicvc_layer.h"
#include "logicvc_of.h"
#include "logicvc_regs.h"

DEFINE_DRM_GEM_DMA_FOPS(logicvc_drm_fops);

static int logicvc_drm_gem_dma_dumb_create(struct drm_file *file_priv,
                                           struct drm_device *drm_dev,
                                           struct drm_mode_create_dumb *args)
{
        struct logicvc_drm *logicvc = logicvc_drm(drm_dev);

        /* Stride is always fixed to its configuration value. */
        args->pitch = logicvc->config.row_stride * DIV_ROUND_UP(args->bpp, 8);

        return drm_gem_dma_dumb_create_internal(file_priv, drm_dev, args);
}

static struct drm_driver logicvc_drm_driver = {
        .driver_features                = DRIVER_GEM | DRIVER_MODESET |
                                          DRIVER_ATOMIC,

        .fops                           = &logicvc_drm_fops,
        .name                           = "logicvc-drm",
        .desc                           = "Xylon LogiCVC DRM driver",
        .major                          = 1,
        .minor                          = 0,

        DRM_GEM_DMA_DRIVER_OPS_VMAP_WITH_DUMB_CREATE(logicvc_drm_gem_dma_dumb_create),
        DRM_FBDEV_DMA_DRIVER_OPS,
};

static struct regmap_config logicvc_drm_regmap_config = {
        .reg_bits       = 32,
        .val_bits       = 32,
        .reg_stride     = 4,
        .name           = "logicvc-drm",
};

static irqreturn_t logicvc_drm_irq_handler(int irq, void *data)
{
        struct logicvc_drm *logicvc = data;
        irqreturn_t ret = IRQ_NONE;
        u32 stat = 0;

        /* Get pending interrupt sources. */
        regmap_read(logicvc->regmap, LOGICVC_INT_STAT_REG, &stat);

        /* Clear all pending interrupt sources. */
        regmap_write(logicvc->regmap, LOGICVC_INT_STAT_REG, stat);

        if (stat & LOGICVC_INT_STAT_V_SYNC) {
                logicvc_crtc_vblank_handler(logicvc);
                ret = IRQ_HANDLED;
        }

        return ret;
}

static int logicvc_drm_config_parse(struct logicvc_drm *logicvc)
{
        struct drm_device *drm_dev = &logicvc->drm_dev;
        struct device *dev = drm_dev->dev;
        struct device_node *of_node = dev->of_node;
        struct logicvc_drm_config *config = &logicvc->config;
        int ret;

        logicvc_of_property_parse_bool(of_node, LOGICVC_OF_PROPERTY_DITHERING,
                                       &config->dithering);
        logicvc_of_property_parse_bool(of_node,
                                       LOGICVC_OF_PROPERTY_BACKGROUND_LAYER,
                                       &config->background_layer);
        logicvc_of_property_parse_bool(of_node,
                                       LOGICVC_OF_PROPERTY_LAYERS_CONFIGURABLE,
                                       &config->layers_configurable);

        ret = logicvc_of_property_parse_u32(of_node,
                                            LOGICVC_OF_PROPERTY_DISPLAY_INTERFACE,
                                            &config->display_interface);
        if (ret)
                return ret;

        ret = logicvc_of_property_parse_u32(of_node,
                                            LOGICVC_OF_PROPERTY_DISPLAY_COLORSPACE,
                                            &config->display_colorspace);
        if (ret)
                return ret;

        ret = logicvc_of_property_parse_u32(of_node,
                                            LOGICVC_OF_PROPERTY_DISPLAY_DEPTH,
                                            &config->display_depth);
        if (ret)
                return ret;

        ret = logicvc_of_property_parse_u32(of_node,
                                            LOGICVC_OF_PROPERTY_ROW_STRIDE,
                                            &config->row_stride);
        if (ret)
                return ret;

        struct device_node *layers_node __free(device_node) =
                of_get_child_by_name(of_node, "layers");
        if (!layers_node) {
                drm_err(drm_dev, "Missing non-optional layers node\n");
                return -EINVAL;
        }

        config->layers_count = of_get_child_count(layers_node);
        if (!config->layers_count) {
                drm_err(drm_dev,
                        "Missing a non-optional layers children node\n");
                return -EINVAL;
        }

        return 0;
}

static int logicvc_clocks_prepare(struct logicvc_drm *logicvc)
{
        struct drm_device *drm_dev = &logicvc->drm_dev;
        struct device *dev = drm_dev->dev;

        struct {
                struct clk **clk;
                char *name;
                bool optional;
        } clocks_map[] = {
                {
                        .clk = &logicvc->vclk,
                        .name = "vclk",
                        .optional = false,
                },
                {
                        .clk = &logicvc->vclk2,
                        .name = "vclk2",
                        .optional = true,
                },
                {
                        .clk = &logicvc->lvdsclk,
                        .name = "lvdsclk",
                        .optional = true,
                },
                {
                        .clk = &logicvc->lvdsclkn,
                        .name = "lvdsclkn",
                        .optional = true,
                },
        };
        unsigned int i;
        int ret;

        for (i = 0; i < ARRAY_SIZE(clocks_map); i++) {
                struct clk *clk;

                clk = devm_clk_get(dev, clocks_map[i].name);
                if (IS_ERR(clk)) {
                        if (PTR_ERR(clk) == -ENOENT && clocks_map[i].optional)
                                continue;

                        drm_err(drm_dev, "Missing non-optional clock %s\n",
                                clocks_map[i].name);

                        ret = PTR_ERR(clk);
                        goto error;
                }

                ret = clk_prepare_enable(clk);
                if (ret) {
                        drm_err(drm_dev,
                                "Failed to prepare and enable clock %s\n",
                                clocks_map[i].name);
                        goto error;
                }

                *clocks_map[i].clk = clk;
        }

        return 0;

error:
        for (i = 0; i < ARRAY_SIZE(clocks_map); i++) {
                if (!*clocks_map[i].clk)
                        continue;

                clk_disable_unprepare(*clocks_map[i].clk);
                *clocks_map[i].clk = NULL;
        }

        return ret;
}

static int logicvc_clocks_unprepare(struct logicvc_drm *logicvc)
{
        struct clk **clocks[] = {
                &logicvc->vclk,
                &logicvc->vclk2,
                &logicvc->lvdsclk,
                &logicvc->lvdsclkn,
        };
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(clocks); i++) {
                if (!*clocks[i])
                        continue;

                clk_disable_unprepare(*clocks[i]);
                *clocks[i] = NULL;
        }

        return 0;
}

static const struct logicvc_drm_caps logicvc_drm_caps[] = {
        {
                .major          = 3,
                .layer_address  = false,
        },
        {
                .major          = 4,
                .layer_address  = true,
        },
        {
                .major          = 5,
                .layer_address  = true,
        },
};

static const struct logicvc_drm_caps *
logicvc_drm_caps_match(struct logicvc_drm *logicvc)
{
        struct drm_device *drm_dev = &logicvc->drm_dev;
        const struct logicvc_drm_caps *caps = NULL;
        unsigned int major, minor;
        char level;
        unsigned int i;
        u32 version;

        regmap_read(logicvc->regmap, LOGICVC_IP_VERSION_REG, &version);

        major = FIELD_GET(LOGICVC_IP_VERSION_MAJOR_MASK, version);
        minor = FIELD_GET(LOGICVC_IP_VERSION_MINOR_MASK, version);
        level = FIELD_GET(LOGICVC_IP_VERSION_LEVEL_MASK, version) + 'a';

        for (i = 0; i < ARRAY_SIZE(logicvc_drm_caps); i++) {
                if (logicvc_drm_caps[i].major &&
                    logicvc_drm_caps[i].major != major)
                        continue;

                if (logicvc_drm_caps[i].minor &&
                    logicvc_drm_caps[i].minor != minor)
                        continue;

                if (logicvc_drm_caps[i].level &&
                    logicvc_drm_caps[i].level != level)
                        continue;

                caps = &logicvc_drm_caps[i];
        }

        drm_info(drm_dev, "LogiCVC version %d.%02d.%c\n", major, minor, level);

        return caps;
}

static int logicvc_drm_probe(struct platform_device *pdev)
{
        struct device_node *of_node = pdev->dev.of_node;
        struct device_node *reserved_mem_node;
        struct reserved_mem *reserved_mem = NULL;
        const struct logicvc_drm_caps *caps;
        struct logicvc_drm *logicvc;
        struct device *dev = &pdev->dev;
        struct drm_device *drm_dev;
        struct regmap *regmap = NULL;
        struct resource res;
        void __iomem *base;
        int irq;
        int ret;

        ret = of_reserved_mem_device_init(dev);
        if (ret && ret != -ENODEV) {
                dev_err(dev, "Failed to init memory region\n");
                goto error_early;
        }

        reserved_mem_node = of_parse_phandle(of_node, "memory-region", 0);
        if (reserved_mem_node) {
                reserved_mem = of_reserved_mem_lookup(reserved_mem_node);
                of_node_put(reserved_mem_node);
        }

        /* Get regmap from parent if available. */
        if (of_node->parent)
                regmap = syscon_node_to_regmap(of_node->parent);

        /* Register our own regmap otherwise. */
        if (IS_ERR_OR_NULL(regmap)) {
                ret = of_address_to_resource(of_node, 0, &res);
                if (ret) {
                        dev_err(dev, "Failed to get resource from address\n");
                        goto error_reserved_mem;
                }

                base = devm_ioremap_resource(dev, &res);
                if (IS_ERR(base)) {
                        dev_err(dev, "Failed to map I/O base\n");
                        ret = PTR_ERR(base);
                        goto error_reserved_mem;
                }

                logicvc_drm_regmap_config.max_register = resource_size(&res) -
                                                         4;

                regmap = devm_regmap_init_mmio(dev, base,
                                               &logicvc_drm_regmap_config);
                if (IS_ERR(regmap)) {
                        dev_err(dev, "Failed to create regmap for I/O\n");
                        ret = PTR_ERR(regmap);
                        goto error_reserved_mem;
                }
        }

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                ret = -ENODEV;
                goto error_reserved_mem;
        }

        logicvc = devm_drm_dev_alloc(dev, &logicvc_drm_driver,
                                     struct logicvc_drm, drm_dev);
        if (IS_ERR(logicvc)) {
                ret = PTR_ERR(logicvc);
                goto error_reserved_mem;
        }

        platform_set_drvdata(pdev, logicvc);
        drm_dev = &logicvc->drm_dev;

        logicvc->regmap = regmap;
        INIT_LIST_HEAD(&logicvc->layers_list);

        caps = logicvc_drm_caps_match(logicvc);
        if (!caps) {
                ret = -EINVAL;
                goto error_reserved_mem;
        }

        logicvc->caps = caps;

        if (reserved_mem)
                logicvc->reserved_mem_base = reserved_mem->base;

        ret = logicvc_clocks_prepare(logicvc);
        if (ret) {
                drm_err(drm_dev, "Failed to prepare clocks\n");
                goto error_reserved_mem;
        }

        ret = devm_request_irq(dev, irq, logicvc_drm_irq_handler, 0,
                               dev_name(dev), logicvc);
        if (ret) {
                drm_err(drm_dev, "Failed to request IRQ\n");
                goto error_clocks;
        }

        ret = logicvc_drm_config_parse(logicvc);
        if (ret && ret != -ENODEV) {
                drm_err(drm_dev, "Failed to parse config\n");
                goto error_clocks;
        }

        ret = drmm_mode_config_init(drm_dev);
        if (ret) {
                drm_err(drm_dev, "Failed to init mode config\n");
                goto error_clocks;
        }

        ret = logicvc_layers_init(logicvc);
        if (ret) {
                drm_err(drm_dev, "Failed to initialize layers\n");
                goto error_clocks;
        }

        ret = logicvc_crtc_init(logicvc);
        if (ret) {
                drm_err(drm_dev, "Failed to initialize CRTC\n");
                goto error_clocks;
        }

        logicvc_layers_attach_crtc(logicvc);

        ret = logicvc_interface_init(logicvc);
        if (ret) {
                if (ret != -EPROBE_DEFER)
                        drm_err(drm_dev, "Failed to initialize interface\n");

                goto error_clocks;
        }

        logicvc_interface_attach_crtc(logicvc);

        ret = logicvc_mode_init(logicvc);
        if (ret) {
                drm_err(drm_dev, "Failed to initialize KMS\n");
                goto error_clocks;
        }

        ret = drm_dev_register(drm_dev, 0);
        if (ret) {
                drm_err(drm_dev, "Failed to register DRM device\n");
                goto error_mode;
        }

        drm_client_setup(drm_dev, NULL);

        return 0;

error_mode:
        logicvc_mode_fini(logicvc);

error_clocks:
        logicvc_clocks_unprepare(logicvc);

error_reserved_mem:
        of_reserved_mem_device_release(dev);

error_early:
        return ret;
}

static void logicvc_drm_remove(struct platform_device *pdev)
{
        struct logicvc_drm *logicvc = platform_get_drvdata(pdev);
        struct device *dev = &pdev->dev;
        struct drm_device *drm_dev = &logicvc->drm_dev;

        drm_dev_unregister(drm_dev);
        drm_atomic_helper_shutdown(drm_dev);

        logicvc_mode_fini(logicvc);

        logicvc_clocks_unprepare(logicvc);

        of_reserved_mem_device_release(dev);
}

static void logicvc_drm_shutdown(struct platform_device *pdev)
{
        struct logicvc_drm *logicvc = platform_get_drvdata(pdev);
        struct drm_device *drm_dev = &logicvc->drm_dev;

        drm_atomic_helper_shutdown(drm_dev);
}

static const struct of_device_id logicvc_drm_of_table[] = {
        { .compatible = "xylon,logicvc-3.02.a-display" },
        { .compatible = "xylon,logicvc-4.01.a-display" },
        {},
};
MODULE_DEVICE_TABLE(of, logicvc_drm_of_table);

static struct platform_driver logicvc_drm_platform_driver = {
        .probe          = logicvc_drm_probe,
        .remove         = logicvc_drm_remove,
        .shutdown       = logicvc_drm_shutdown,
        .driver         = {
                .name           = "logicvc-drm",
                .of_match_table = logicvc_drm_of_table,
        },
};

module_platform_driver(logicvc_drm_platform_driver);

MODULE_AUTHOR("Paul Kocialkowski <paul.kocialkowski@bootlin.com>");
MODULE_DESCRIPTION("Xylon LogiCVC DRM driver");
MODULE_LICENSE("GPL");