// SPDX-License-Identifier: GPL-2.0-only

#include <linux/clk.h>
#include <linux/of_clk.h>
#include <linux/platform_data/simplefb.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>

#include <drm/drm_aperture.h>
#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_connector.h>
#include <drm/drm_damage_helper.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_format_helper.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_gem_shmem_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>

#define DRIVER_NAME     "simpledrm"
#define DRIVER_DESC     "DRM driver for simple-framebuffer platform devices"
#define DRIVER_DATE     "20200625"
#define DRIVER_MAJOR    1
#define DRIVER_MINOR    0

/*
 * Assume a monitor resolution of 96 dpi to
 * get a somewhat reasonable screen size.
 */
#define RES_MM(d)       \
        (((d) * 254ul) / (96ul * 10ul))

#define SIMPLEDRM_MODE(hd, vd)  \
        DRM_SIMPLE_MODE(hd, vd, RES_MM(hd), RES_MM(vd))

/*
 * Helpers for simplefb
 */

static int
simplefb_get_validated_int(struct drm_device *dev, const char *name,
                           uint32_t value)
{
        if (value > INT_MAX) {
                drm_err(dev, "simplefb: invalid framebuffer %s of %u\n",
                        name, value);
                return -EINVAL;
        }
        return (int)value;
}

static int
simplefb_get_validated_int0(struct drm_device *dev, const char *name,
                            uint32_t value)
{
        if (!value) {
                drm_err(dev, "simplefb: invalid framebuffer %s of %u\n",
                        name, value);
                return -EINVAL;
        }
        return simplefb_get_validated_int(dev, name, value);
}

static const struct drm_format_info *
simplefb_get_validated_format(struct drm_device *dev, const char *format_name)
{
        static const struct simplefb_format formats[] = SIMPLEFB_FORMATS;
        const struct simplefb_format *fmt = formats;
        const struct simplefb_format *end = fmt + ARRAY_SIZE(formats);
        const struct drm_format_info *info;

        if (!format_name) {
                drm_err(dev, "simplefb: missing framebuffer format\n");
                return ERR_PTR(-EINVAL);
        }

        while (fmt < end) {
                if (!strcmp(format_name, fmt->name)) {
                        info = drm_format_info(fmt->fourcc);
                        if (!info)
                                return ERR_PTR(-EINVAL);
                        return info;
                }
                ++fmt;
        }

        drm_err(dev, "simplefb: unknown framebuffer format %s\n",
                format_name);

        return ERR_PTR(-EINVAL);
}

static int
simplefb_get_width_pd(struct drm_device *dev,
                      const struct simplefb_platform_data *pd)
{
        return simplefb_get_validated_int0(dev, "width", pd->width);
}

static int
simplefb_get_height_pd(struct drm_device *dev,
                       const struct simplefb_platform_data *pd)
{
        return simplefb_get_validated_int0(dev, "height", pd->height);
}

static int
simplefb_get_stride_pd(struct drm_device *dev,
                       const struct simplefb_platform_data *pd)
{
        return simplefb_get_validated_int(dev, "stride", pd->stride);
}

static const struct drm_format_info *
simplefb_get_format_pd(struct drm_device *dev,
                       const struct simplefb_platform_data *pd)
{
        return simplefb_get_validated_format(dev, pd->format);
}

static int
simplefb_read_u32_of(struct drm_device *dev, struct device_node *of_node,
                     const char *name, u32 *value)
{
        int ret = of_property_read_u32(of_node, name, value);

        if (ret)
                drm_err(dev, "simplefb: cannot parse framebuffer %s: error %d\n",
                        name, ret);
        return ret;
}

static int
simplefb_read_string_of(struct drm_device *dev, struct device_node *of_node,
                        const char *name, const char **value)
{
        int ret = of_property_read_string(of_node, name, value);

        if (ret)
                drm_err(dev, "simplefb: cannot parse framebuffer %s: error %d\n",
                        name, ret);
        return ret;
}

static int
simplefb_get_width_of(struct drm_device *dev, struct device_node *of_node)
{
        u32 width;
        int ret = simplefb_read_u32_of(dev, of_node, "width", &width);

        if (ret)
                return ret;
        return simplefb_get_validated_int0(dev, "width", width);
}

static int
simplefb_get_height_of(struct drm_device *dev, struct device_node *of_node)
{
        u32 height;
        int ret = simplefb_read_u32_of(dev, of_node, "height", &height);

        if (ret)
                return ret;
        return simplefb_get_validated_int0(dev, "height", height);
}

static int
simplefb_get_stride_of(struct drm_device *dev, struct device_node *of_node)
{
        u32 stride;
        int ret = simplefb_read_u32_of(dev, of_node, "stride", &stride);

        if (ret)
                return ret;
        return simplefb_get_validated_int(dev, "stride", stride);
}

static const struct drm_format_info *
simplefb_get_format_of(struct drm_device *dev, struct device_node *of_node)
{
        const char *format;
        int ret = simplefb_read_string_of(dev, of_node, "format", &format);

        if (ret)
                return ERR_PTR(ret);
        return simplefb_get_validated_format(dev, format);
}

/*
 * Simple Framebuffer device
 */

struct simpledrm_device {
        struct drm_device dev;
        struct platform_device *pdev;

        /* clocks */
#if defined CONFIG_OF && defined CONFIG_COMMON_CLK
        unsigned int clk_count;
        struct clk **clks;
#endif
        /* regulators */
#if defined CONFIG_OF && defined CONFIG_REGULATOR
        unsigned int regulator_count;
        struct regulator **regulators;
#endif

        /* simplefb settings */
        struct drm_display_mode mode;
        const struct drm_format_info *format;
        unsigned int pitch;

        /* memory management */
        struct resource *mem;
        void __iomem *screen_base;

        /* modesetting */
        uint32_t formats[8];
        size_t nformats;
        struct drm_connector connector;
        struct drm_simple_display_pipe pipe;
};

static struct simpledrm_device *simpledrm_device_of_dev(struct drm_device *dev)
{
        return container_of(dev, struct simpledrm_device, dev);
}

/*
 * Hardware
 */

#if defined CONFIG_OF && defined CONFIG_COMMON_CLK
/*
 * Clock handling code.
 *
 * Here we handle the clocks property of our "simple-framebuffer" dt node.
 * This is necessary so that we can make sure that any clocks needed by
 * the display engine that the bootloader set up for us (and for which it
 * provided a simplefb dt node), stay up, for the life of the simplefb
 * driver.
 *
 * When the driver unloads, we cleanly disable, and then release the clocks.
 *
 * We only complain about errors here, no action is taken as the most likely
 * error can only happen due to a mismatch between the bootloader which set
 * up simplefb, and the clock definitions in the device tree. Chances are
 * that there are no adverse effects, and if there are, a clean teardown of
 * the fb probe will not help us much either. So just complain and carry on,
 * and hope that the user actually gets a working fb at the end of things.
 */

static void simpledrm_device_release_clocks(void *res)
{
        struct simpledrm_device *sdev = simpledrm_device_of_dev(res);
        unsigned int i;

        for (i = 0; i < sdev->clk_count; ++i) {
                if (sdev->clks[i]) {
                        clk_disable_unprepare(sdev->clks[i]);
                        clk_put(sdev->clks[i]);
                }
        }
}

static int simpledrm_device_init_clocks(struct simpledrm_device *sdev)
{
        struct drm_device *dev = &sdev->dev;
        struct platform_device *pdev = sdev->pdev;
        struct device_node *of_node = pdev->dev.of_node;
        struct clk *clock;
        unsigned int i;
        int ret;

        if (dev_get_platdata(&pdev->dev) || !of_node)
                return 0;

        sdev->clk_count = of_clk_get_parent_count(of_node);
        if (!sdev->clk_count)
                return 0;

        sdev->clks = drmm_kzalloc(dev, sdev->clk_count * sizeof(sdev->clks[0]),
                                  GFP_KERNEL);
        if (!sdev->clks)
                return -ENOMEM;

        for (i = 0; i < sdev->clk_count; ++i) {
                clock = of_clk_get(of_node, i);
                if (IS_ERR(clock)) {
                        ret = PTR_ERR(clock);
                        if (ret == -EPROBE_DEFER)
                                goto err;
                        drm_err(dev, "clock %u not found: %d\n", i, ret);
                        continue;
                }
                ret = clk_prepare_enable(clock);
                if (ret) {
                        drm_err(dev, "failed to enable clock %u: %d\n",
                                i, ret);
                        clk_put(clock);
                        continue;
                }
                sdev->clks[i] = clock;
        }

        return devm_add_action_or_reset(&pdev->dev,
                                        simpledrm_device_release_clocks,
                                        sdev);

err:
        while (i) {
                --i;
                if (sdev->clks[i]) {
                        clk_disable_unprepare(sdev->clks[i]);
                        clk_put(sdev->clks[i]);
                }
        }
        return ret;
}
#else
static int simpledrm_device_init_clocks(struct simpledrm_device *sdev)
{
        return 0;
}
#endif

#if defined CONFIG_OF && defined CONFIG_REGULATOR

#define SUPPLY_SUFFIX "-supply"

/*
 * Regulator handling code.
 *
 * Here we handle the num-supplies and vin*-supply properties of our
 * "simple-framebuffer" dt node. This is necessary so that we can make sure
 * that any regulators needed by the display hardware that the bootloader
 * set up for us (and for which it provided a simplefb dt node), stay up,
 * for the life of the simplefb driver.
 *
 * When the driver unloads, we cleanly disable, and then release the
 * regulators.
 *
 * We only complain about errors here, no action is taken as the most likely
 * error can only happen due to a mismatch between the bootloader which set
 * up simplefb, and the regulator definitions in the device tree. Chances are
 * that there are no adverse effects, and if there are, a clean teardown of
 * the fb probe will not help us much either. So just complain and carry on,
 * and hope that the user actually gets a working fb at the end of things.
 */

static void simpledrm_device_release_regulators(void *res)
{
        struct simpledrm_device *sdev = simpledrm_device_of_dev(res);
        unsigned int i;

        for (i = 0; i < sdev->regulator_count; ++i) {
                if (sdev->regulators[i]) {
                        regulator_disable(sdev->regulators[i]);
                        regulator_put(sdev->regulators[i]);
                }
        }
}

static int simpledrm_device_init_regulators(struct simpledrm_device *sdev)
{
        struct drm_device *dev = &sdev->dev;
        struct platform_device *pdev = sdev->pdev;
        struct device_node *of_node = pdev->dev.of_node;
        struct property *prop;
        struct regulator *regulator;
        const char *p;
        unsigned int count = 0, i = 0;
        int ret;

        if (dev_get_platdata(&pdev->dev) || !of_node)
                return 0;

        /* Count the number of regulator supplies */
        for_each_property_of_node(of_node, prop) {
                p = strstr(prop->name, SUPPLY_SUFFIX);
                if (p && p != prop->name)
                        ++count;
        }

        if (!count)
                return 0;

        sdev->regulators = drmm_kzalloc(dev,
                                        count * sizeof(sdev->regulators[0]),
                                        GFP_KERNEL);
        if (!sdev->regulators)
                return -ENOMEM;

        for_each_property_of_node(of_node, prop) {
                char name[32]; /* 32 is max size of property name */
                size_t len;

                p = strstr(prop->name, SUPPLY_SUFFIX);
                if (!p || p == prop->name)
                        continue;
                len = strlen(prop->name) - strlen(SUPPLY_SUFFIX) + 1;
                strscpy(name, prop->name, min(sizeof(name), len));

                regulator = regulator_get_optional(&pdev->dev, name);
                if (IS_ERR(regulator)) {
                        ret = PTR_ERR(regulator);
                        if (ret == -EPROBE_DEFER)
                                goto err;
                        drm_err(dev, "regulator %s not found: %d\n",
                                name, ret);
                        continue;
                }

                ret = regulator_enable(regulator);
                if (ret) {
                        drm_err(dev, "failed to enable regulator %u: %d\n",
                                i, ret);
                        regulator_put(regulator);
                        continue;
                }

                sdev->regulators[i++] = regulator;
        }
        sdev->regulator_count = i;

        return devm_add_action_or_reset(&pdev->dev,
                                        simpledrm_device_release_regulators,
                                        sdev);

err:
        while (i) {
                --i;
                if (sdev->regulators[i]) {
                        regulator_disable(sdev->regulators[i]);
                        regulator_put(sdev->regulators[i]);
                }
        }
        return ret;
}
#else
static int simpledrm_device_init_regulators(struct simpledrm_device *sdev)
{
        return 0;
}
#endif

/*
 *  Simplefb settings
 */

static struct drm_display_mode simpledrm_mode(unsigned int width,
                                              unsigned int height)
{
        struct drm_display_mode mode = { SIMPLEDRM_MODE(width, height) };

        mode.clock = 60 /* Hz */ * mode.hdisplay * mode.vdisplay;
        drm_mode_set_name(&mode);

        return mode;
}

static int simpledrm_device_init_fb(struct simpledrm_device *sdev)
{
        int width, height, stride;
        const struct drm_format_info *format;
        struct drm_device *dev = &sdev->dev;
        struct platform_device *pdev = sdev->pdev;
        const struct simplefb_platform_data *pd = dev_get_platdata(&pdev->dev);
        struct device_node *of_node = pdev->dev.of_node;

        if (pd) {
                width = simplefb_get_width_pd(dev, pd);
                if (width < 0)
                        return width;
                height = simplefb_get_height_pd(dev, pd);
                if (height < 0)
                        return height;
                stride = simplefb_get_stride_pd(dev, pd);
                if (stride < 0)
                        return stride;
                format = simplefb_get_format_pd(dev, pd);
                if (IS_ERR(format))
                        return PTR_ERR(format);
        } else if (of_node) {
                width = simplefb_get_width_of(dev, of_node);
                if (width < 0)
                        return width;
                height = simplefb_get_height_of(dev, of_node);
                if (height < 0)
                        return height;
                stride = simplefb_get_stride_of(dev, of_node);
                if (stride < 0)
                        return stride;
                format = simplefb_get_format_of(dev, of_node);
                if (IS_ERR(format))
                        return PTR_ERR(format);
        } else {
                drm_err(dev, "no simplefb configuration found\n");
                return -ENODEV;
        }

        sdev->mode = simpledrm_mode(width, height);
        sdev->format = format;
        sdev->pitch = stride;

        drm_dbg_kms(dev, "display mode={" DRM_MODE_FMT "}\n",
                    DRM_MODE_ARG(&sdev->mode));
        drm_dbg_kms(dev,
                    "framebuffer format=%p4cc, size=%dx%d, stride=%d byte\n",
                    &format->format, width, height, stride);

        return 0;
}

/*
 * Memory management
 */

static int simpledrm_device_init_mm(struct simpledrm_device *sdev)
{
        struct drm_device *dev = &sdev->dev;
        struct platform_device *pdev = sdev->pdev;
        struct resource *mem;
        void __iomem *screen_base;
        int ret;

        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!mem)
                return -EINVAL;

        ret = devm_aperture_acquire_from_firmware(dev, mem->start, resource_size(mem));
        if (ret) {
                drm_err(dev, "could not acquire memory range %pr: error %d\n",
                        mem, ret);
                return ret;
        }

        screen_base = devm_ioremap_wc(&pdev->dev, mem->start,
                                      resource_size(mem));
        if (!screen_base)
                return -ENOMEM;

        sdev->mem = mem;
        sdev->screen_base = screen_base;

        return 0;
}

/*
 * Modesetting
 */

/*
 * Support all formats of simplefb and maybe more; in order
 * of preference. The display's update function will do any
 * conversion necessary.
 *
 * TODO: Add blit helpers for remaining formats and uncomment
 *       constants.
 */
static const uint32_t simpledrm_default_formats[] = {
        DRM_FORMAT_XRGB8888,
        DRM_FORMAT_ARGB8888,
        DRM_FORMAT_RGB565,
        //DRM_FORMAT_XRGB1555,
        //DRM_FORMAT_ARGB1555,
        DRM_FORMAT_RGB888,
        //DRM_FORMAT_XRGB2101010,
        //DRM_FORMAT_ARGB2101010,
};

static const uint64_t simpledrm_format_modifiers[] = {
        DRM_FORMAT_MOD_LINEAR,
        DRM_FORMAT_MOD_INVALID
};

static int simpledrm_connector_helper_get_modes(struct drm_connector *connector)
{
        struct simpledrm_device *sdev = simpledrm_device_of_dev(connector->dev);
        struct drm_display_mode *mode;

        mode = drm_mode_duplicate(connector->dev, &sdev->mode);
        if (!mode)
                return 0;

        if (mode->name[0] == '\0')
                drm_mode_set_name(mode);

        mode->type |= DRM_MODE_TYPE_PREFERRED;
        drm_mode_probed_add(connector, mode);

        if (mode->width_mm)
                connector->display_info.width_mm = mode->width_mm;
        if (mode->height_mm)
                connector->display_info.height_mm = mode->height_mm;

        return 1;
}

static const struct drm_connector_helper_funcs simpledrm_connector_helper_funcs = {
        .get_modes = simpledrm_connector_helper_get_modes,
};

static const struct drm_connector_funcs simpledrm_connector_funcs = {
        .reset = drm_atomic_helper_connector_reset,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .destroy = drm_connector_cleanup,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static int
simpledrm_simple_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
                                    const struct drm_display_mode *mode)
{
        struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);

        if (mode->hdisplay != sdev->mode.hdisplay &&
            mode->vdisplay != sdev->mode.vdisplay)
                return MODE_ONE_SIZE;
        else if (mode->hdisplay != sdev->mode.hdisplay)
                return MODE_ONE_WIDTH;
        else if (mode->vdisplay != sdev->mode.vdisplay)
                return MODE_ONE_HEIGHT;

        return MODE_OK;
}

static void
simpledrm_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
                                     struct drm_crtc_state *crtc_state,
                                     struct drm_plane_state *plane_state)
{
        struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
        struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
        struct drm_framebuffer *fb = plane_state->fb;
        void *vmap = shadow_plane_state->data[0].vaddr; /* TODO: Use mapping abstraction */
        struct drm_device *dev = &sdev->dev;
        int idx;

        if (!fb)
                return;

        if (!drm_dev_enter(dev, &idx))
                return;

        drm_fb_blit_dstclip(sdev->screen_base, sdev->pitch,
                            sdev->format->format, vmap, fb);
        drm_dev_exit(idx);
}

static void
simpledrm_simple_display_pipe_disable(struct drm_simple_display_pipe *pipe)
{
        struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
        struct drm_device *dev = &sdev->dev;
        int idx;

        if (!drm_dev_enter(dev, &idx))
                return;

        /* Clear screen to black if disabled */
        memset_io(sdev->screen_base, 0, sdev->pitch * sdev->mode.vdisplay);

        drm_dev_exit(idx);
}

static void
simpledrm_simple_display_pipe_update(struct drm_simple_display_pipe *pipe,
                                     struct drm_plane_state *old_plane_state)
{
        struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
        struct drm_plane_state *plane_state = pipe->plane.state;
        struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
        void *vmap = shadow_plane_state->data[0].vaddr; /* TODO: Use mapping abstraction */
        struct drm_framebuffer *fb = plane_state->fb;
        struct drm_device *dev = &sdev->dev;
        struct drm_rect clip;
        int idx;

        if (!fb)
                return;

        if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state, &clip))
                return;

        if (!drm_dev_enter(dev, &idx))
                return;

        drm_fb_blit_rect_dstclip(sdev->screen_base, sdev->pitch,
                                 sdev->format->format, vmap, fb, &clip);

        drm_dev_exit(idx);
}

static const struct drm_simple_display_pipe_funcs
simpledrm_simple_display_pipe_funcs = {
        .mode_valid = simpledrm_simple_display_pipe_mode_valid,
        .enable = simpledrm_simple_display_pipe_enable,
        .disable = simpledrm_simple_display_pipe_disable,
        .update = simpledrm_simple_display_pipe_update,
        DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
};

static const struct drm_mode_config_funcs simpledrm_mode_config_funcs = {
        .fb_create = drm_gem_fb_create_with_dirty,
        .atomic_check = drm_atomic_helper_check,
        .atomic_commit = drm_atomic_helper_commit,
};

static const uint32_t *simpledrm_device_formats(struct simpledrm_device *sdev,
                                                size_t *nformats_out)
{
        struct drm_device *dev = &sdev->dev;
        size_t i;

        if (sdev->nformats)
                goto out; /* don't rebuild list on recurring calls */

        /* native format goes first */
        sdev->formats[0] = sdev->format->format;
        sdev->nformats = 1;

        /* default formats go second */
        for (i = 0; i < ARRAY_SIZE(simpledrm_default_formats); ++i) {
                if (simpledrm_default_formats[i] == sdev->format->format)
                        continue; /* native format already went first */
                sdev->formats[sdev->nformats] = simpledrm_default_formats[i];
                sdev->nformats++;
        }

        /*
         * TODO: The simpledrm driver converts framebuffers to the native
         * format when copying them to device memory. If there are more
         * formats listed than supported by the driver, the native format
         * is not supported by the conversion helpers. Therefore *only*
         * support the native format and add a conversion helper ASAP.
         */
        if (drm_WARN_ONCE(dev, i != sdev->nformats,
                          "format conversion helpers required for %p4cc",
                          &sdev->format->format)) {
                sdev->nformats = 1;
        }

out:
        *nformats_out = sdev->nformats;
        return sdev->formats;
}

static int simpledrm_device_init_modeset(struct simpledrm_device *sdev)
{
        struct drm_device *dev = &sdev->dev;
        struct drm_display_mode *mode = &sdev->mode;
        struct drm_connector *connector = &sdev->connector;
        struct drm_simple_display_pipe *pipe = &sdev->pipe;
        const uint32_t *formats;
        size_t nformats;
        int ret;

        ret = drmm_mode_config_init(dev);
        if (ret)
                return ret;

        dev->mode_config.min_width = mode->hdisplay;
        dev->mode_config.max_width = mode->hdisplay;
        dev->mode_config.min_height = mode->vdisplay;
        dev->mode_config.max_height = mode->vdisplay;
        dev->mode_config.prefer_shadow_fbdev = true;
        dev->mode_config.preferred_depth = sdev->format->cpp[0] * 8;
        dev->mode_config.funcs = &simpledrm_mode_config_funcs;

        ret = drm_connector_init(dev, connector, &simpledrm_connector_funcs,
                                 DRM_MODE_CONNECTOR_Unknown);
        if (ret)
                return ret;
        drm_connector_helper_add(connector, &simpledrm_connector_helper_funcs);

        formats = simpledrm_device_formats(sdev, &nformats);

        ret = drm_simple_display_pipe_init(dev, pipe, &simpledrm_simple_display_pipe_funcs,
                                           formats, nformats, simpledrm_format_modifiers,
                                           connector);
        if (ret)
                return ret;

        drm_mode_config_reset(dev);

        return 0;
}

/*
 * Init / Cleanup
 */

static struct simpledrm_device *
simpledrm_device_create(struct drm_driver *drv, struct platform_device *pdev)
{
        struct simpledrm_device *sdev;
        int ret;

        sdev = devm_drm_dev_alloc(&pdev->dev, drv, struct simpledrm_device,
                                  dev);
        if (IS_ERR(sdev))
                return ERR_CAST(sdev);
        sdev->pdev = pdev;
        platform_set_drvdata(pdev, sdev);

        ret = simpledrm_device_init_clocks(sdev);
        if (ret)
                return ERR_PTR(ret);
        ret = simpledrm_device_init_regulators(sdev);
        if (ret)
                return ERR_PTR(ret);
        ret = simpledrm_device_init_fb(sdev);
        if (ret)
                return ERR_PTR(ret);
        ret = simpledrm_device_init_mm(sdev);
        if (ret)
                return ERR_PTR(ret);
        ret = simpledrm_device_init_modeset(sdev);
        if (ret)
                return ERR_PTR(ret);

        return sdev;
}

/*
 * DRM driver
 */

DEFINE_DRM_GEM_FOPS(simpledrm_fops);

static struct drm_driver simpledrm_driver = {
        DRM_GEM_SHMEM_DRIVER_OPS,
        .name                   = DRIVER_NAME,
        .desc                   = DRIVER_DESC,
        .date                   = DRIVER_DATE,
        .major                  = DRIVER_MAJOR,
        .minor                  = DRIVER_MINOR,
        .driver_features        = DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
        .fops                   = &simpledrm_fops,
};

/*
 * Platform driver
 */

static int simpledrm_probe(struct platform_device *pdev)
{
        struct simpledrm_device *sdev;
        struct drm_device *dev;
        int ret;

        sdev = simpledrm_device_create(&simpledrm_driver, pdev);
        if (IS_ERR(sdev))
                return PTR_ERR(sdev);
        dev = &sdev->dev;

        ret = drm_dev_register(dev, 0);
        if (ret)
                return ret;

        drm_fbdev_generic_setup(dev, 0);

        return 0;
}

static int simpledrm_remove(struct platform_device *pdev)
{
        struct simpledrm_device *sdev = platform_get_drvdata(pdev);
        struct drm_device *dev = &sdev->dev;

        drm_dev_unplug(dev);

        return 0;
}

static const struct of_device_id simpledrm_of_match_table[] = {
        { .compatible = "simple-framebuffer", },
        { },
};
MODULE_DEVICE_TABLE(of, simpledrm_of_match_table);

static struct platform_driver simpledrm_platform_driver = {
        .driver = {
                .name = "simple-framebuffer", /* connect to sysfb */
                .of_match_table = simpledrm_of_match_table,
        },
        .probe = simpledrm_probe,
        .remove = simpledrm_remove,
};

module_platform_driver(simpledrm_platform_driver);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL v2");