root/drivers/gpu/drm/bridge/imx/imx8qxp-pxl2dpi.c
// SPDX-License-Identifier: GPL-2.0+

/*
 * Copyright 2020 NXP
 */

#include <linux/firmware/imx/svc/misc.h>
#include <linux/media-bus-format.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>

#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>

#include <dt-bindings/firmware/imx/rsrc.h>

#define PXL2DPI_CTRL    0x40
#define  CFG1_16BIT     0x0
#define  CFG2_16BIT     0x1
#define  CFG3_16BIT     0x2
#define  CFG1_18BIT     0x3
#define  CFG2_18BIT     0x4
#define  CFG_24BIT      0x5

#define DRIVER_NAME     "imx8qxp-pxl2dpi"

struct imx8qxp_pxl2dpi {
        struct regmap *regmap;
        struct drm_bridge bridge;
        struct drm_bridge *companion;
        struct device *dev;
        struct imx_sc_ipc *ipc_handle;
        u32 sc_resource;
        u32 in_bus_format;
        u32 out_bus_format;
        u32 pl_sel;
};

#define bridge_to_p2d(b)        container_of(b, struct imx8qxp_pxl2dpi, bridge)

static int imx8qxp_pxl2dpi_bridge_attach(struct drm_bridge *bridge,
                                         struct drm_encoder *encoder,
                                         enum drm_bridge_attach_flags flags)
{
        struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;

        if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
                DRM_DEV_ERROR(p2d->dev,
                              "do not support creating a drm_connector\n");
                return -EINVAL;
        }

        return drm_bridge_attach(encoder,
                                 p2d->bridge.next_bridge, bridge,
                                 DRM_BRIDGE_ATTACH_NO_CONNECTOR);
}

static void imx8qxp_pxl2dpi_bridge_destroy(struct drm_bridge *bridge)
{
        struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;

        if (!p2d)
                return;

        drm_bridge_put(p2d->companion);
}

static int
imx8qxp_pxl2dpi_bridge_atomic_check(struct drm_bridge *bridge,
                                    struct drm_bridge_state *bridge_state,
                                    struct drm_crtc_state *crtc_state,
                                    struct drm_connector_state *conn_state)
{
        struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;

        p2d->in_bus_format = bridge_state->input_bus_cfg.format;
        p2d->out_bus_format = bridge_state->output_bus_cfg.format;

        return 0;
}

static void
imx8qxp_pxl2dpi_bridge_mode_set(struct drm_bridge *bridge,
                                const struct drm_display_mode *mode,
                                const struct drm_display_mode *adjusted_mode)
{
        struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;
        struct imx8qxp_pxl2dpi *companion_p2d;
        int ret;

        ret = pm_runtime_get_sync(p2d->dev);
        if (ret < 0)
                DRM_DEV_ERROR(p2d->dev,
                              "failed to get runtime PM sync: %d\n", ret);

        ret = imx_sc_misc_set_control(p2d->ipc_handle, p2d->sc_resource,
                                      IMX_SC_C_PXL_LINK_SEL, p2d->pl_sel);
        if (ret)
                DRM_DEV_ERROR(p2d->dev,
                              "failed to set pixel link selection(%u): %d\n",
                                                        p2d->pl_sel, ret);

        switch (p2d->out_bus_format) {
        case MEDIA_BUS_FMT_RGB888_1X24:
                regmap_write(p2d->regmap, PXL2DPI_CTRL, CFG_24BIT);
                break;
        case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
                regmap_write(p2d->regmap, PXL2DPI_CTRL, CFG2_18BIT);
                break;
        default:
                DRM_DEV_ERROR(p2d->dev,
                              "unsupported output bus format 0x%08x\n",
                                                        p2d->out_bus_format);
        }

        if (p2d->companion) {
                companion_p2d = bridge_to_p2d(p2d->companion);

                companion_p2d->in_bus_format = p2d->in_bus_format;
                companion_p2d->out_bus_format = p2d->out_bus_format;

                p2d->companion->funcs->mode_set(p2d->companion, mode,
                                                        adjusted_mode);
        }
}

static void imx8qxp_pxl2dpi_bridge_atomic_disable(struct drm_bridge *bridge,
                                                  struct drm_atomic_state *state)
{
        struct imx8qxp_pxl2dpi *p2d = bridge->driver_private;

        pm_runtime_put(p2d->dev);

        if (p2d->companion)
                p2d->companion->funcs->atomic_disable(p2d->companion, state);
}

static const u32 imx8qxp_pxl2dpi_bus_output_fmts[] = {
        MEDIA_BUS_FMT_RGB888_1X24,
        MEDIA_BUS_FMT_RGB666_1X24_CPADHI,
};

static bool imx8qxp_pxl2dpi_bus_output_fmt_supported(u32 fmt)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(imx8qxp_pxl2dpi_bus_output_fmts); i++) {
                if (imx8qxp_pxl2dpi_bus_output_fmts[i] == fmt)
                        return true;
        }

        return false;
}

static u32 *
imx8qxp_pxl2dpi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
                                                 struct drm_bridge_state *bridge_state,
                                                 struct drm_crtc_state *crtc_state,
                                                 struct drm_connector_state *conn_state,
                                                 u32 output_fmt,
                                                 unsigned int *num_input_fmts)
{
        u32 *input_fmts;

        if (!imx8qxp_pxl2dpi_bus_output_fmt_supported(output_fmt))
                return NULL;

        *num_input_fmts = 1;

        input_fmts = kmalloc_obj(*input_fmts);
        if (!input_fmts)
                return NULL;

        switch (output_fmt) {
        case MEDIA_BUS_FMT_RGB888_1X24:
                input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X36_CPADLO;
                break;
        case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
                input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X36_CPADLO;
                break;
        default:
                kfree(input_fmts);
                input_fmts = NULL;
                break;
        }

        return input_fmts;
}

static u32 *
imx8qxp_pxl2dpi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
                                                  struct drm_bridge_state *bridge_state,
                                                  struct drm_crtc_state *crtc_state,
                                                  struct drm_connector_state *conn_state,
                                                  unsigned int *num_output_fmts)
{
        *num_output_fmts = ARRAY_SIZE(imx8qxp_pxl2dpi_bus_output_fmts);
        return kmemdup(imx8qxp_pxl2dpi_bus_output_fmts,
                        sizeof(imx8qxp_pxl2dpi_bus_output_fmts), GFP_KERNEL);
}

static const struct drm_bridge_funcs imx8qxp_pxl2dpi_bridge_funcs = {
        .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
        .atomic_destroy_state   = drm_atomic_helper_bridge_destroy_state,
        .atomic_reset           = drm_atomic_helper_bridge_reset,
        .attach                 = imx8qxp_pxl2dpi_bridge_attach,
        .destroy                = imx8qxp_pxl2dpi_bridge_destroy,
        .atomic_check           = imx8qxp_pxl2dpi_bridge_atomic_check,
        .mode_set               = imx8qxp_pxl2dpi_bridge_mode_set,
        .atomic_disable         = imx8qxp_pxl2dpi_bridge_atomic_disable,
        .atomic_get_input_bus_fmts =
                        imx8qxp_pxl2dpi_bridge_atomic_get_input_bus_fmts,
        .atomic_get_output_bus_fmts =
                        imx8qxp_pxl2dpi_bridge_atomic_get_output_bus_fmts,
};

static struct device_node *
imx8qxp_pxl2dpi_get_available_ep_from_port(struct imx8qxp_pxl2dpi *p2d,
                                           u32 port_id)
{
        struct device_node *port, *ep;
        int ep_cnt;

        port = of_graph_get_port_by_id(p2d->dev->of_node, port_id);
        if (!port) {
                DRM_DEV_ERROR(p2d->dev, "failed to get port@%u\n", port_id);
                return ERR_PTR(-ENODEV);
        }

        ep_cnt = of_get_available_child_count(port);
        if (ep_cnt == 0) {
                DRM_DEV_ERROR(p2d->dev, "no available endpoints of port@%u\n",
                              port_id);
                ep = ERR_PTR(-ENODEV);
                goto out;
        } else if (ep_cnt > 1) {
                DRM_DEV_ERROR(p2d->dev,
                              "invalid available endpoints of port@%u\n",
                              port_id);
                ep = ERR_PTR(-EINVAL);
                goto out;
        }

        ep = of_get_next_available_child(port, NULL);
        if (!ep) {
                DRM_DEV_ERROR(p2d->dev,
                              "failed to get available endpoint of port@%u\n",
                              port_id);
                ep = ERR_PTR(-ENODEV);
                goto out;
        }
out:
        of_node_put(port);
        return ep;
}

static int imx8qxp_pxl2dpi_find_next_bridge(struct imx8qxp_pxl2dpi *p2d)
{
        struct device_node *ep __free(device_node) =
                imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 1);
        if (IS_ERR(ep))
                return PTR_ERR(ep);

        struct device_node *remote __free(device_node) = of_graph_get_remote_port_parent(ep);
        if (!remote || !of_device_is_available(remote)) {
                DRM_DEV_ERROR(p2d->dev, "no available remote\n");
                return -ENODEV;
        } else if (!of_device_is_available(remote->parent)) {
                DRM_DEV_ERROR(p2d->dev, "remote parent is not available\n");
                return -ENODEV;
        }

        p2d->bridge.next_bridge = of_drm_find_and_get_bridge(remote);
        if (!p2d->bridge.next_bridge)
                return -EPROBE_DEFER;

        return 0;
}

static int imx8qxp_pxl2dpi_set_pixel_link_sel(struct imx8qxp_pxl2dpi *p2d)
{
        struct device_node *ep;
        struct of_endpoint endpoint;
        int ret;

        ep = imx8qxp_pxl2dpi_get_available_ep_from_port(p2d, 0);
        if (IS_ERR(ep))
                return PTR_ERR(ep);

        ret = of_graph_parse_endpoint(ep, &endpoint);
        if (ret) {
                DRM_DEV_ERROR(p2d->dev,
                              "failed to parse endpoint of port@0: %d\n", ret);
                goto out;
        }

        p2d->pl_sel = endpoint.id;
out:
        of_node_put(ep);

        return ret;
}

static int imx8qxp_pxl2dpi_parse_dt_companion(struct imx8qxp_pxl2dpi *p2d)
{
        struct imx8qxp_pxl2dpi *companion_p2d;
        struct device *dev = p2d->dev;
        struct device_node *companion;
        struct device_node *port1, *port2;
        const struct of_device_id *match;
        int dual_link;
        int ret = 0;

        /* Locate the companion PXL2DPI for dual-link operation, if any. */
        companion = of_parse_phandle(dev->of_node, "fsl,companion-pxl2dpi", 0);
        if (!companion)
                return 0;

        if (!of_device_is_available(companion)) {
                DRM_DEV_ERROR(dev, "companion PXL2DPI is not available\n");
                ret = -ENODEV;
                goto out;
        }

        /*
         * Sanity check: the companion bridge must have the same compatible
         * string.
         */
        match = of_match_device(dev->driver->of_match_table, dev);
        if (!of_device_is_compatible(companion, match->compatible)) {
                DRM_DEV_ERROR(dev, "companion PXL2DPI is incompatible\n");
                ret = -ENXIO;
                goto out;
        }

        p2d->companion = of_drm_find_and_get_bridge(companion);
        if (!p2d->companion) {
                ret = -EPROBE_DEFER;
                DRM_DEV_DEBUG_DRIVER(p2d->dev,
                                     "failed to find companion bridge: %d\n",
                                     ret);
                goto out;
        }

        companion_p2d = bridge_to_p2d(p2d->companion);

        /*
         * We need to work out if the sink is expecting us to function in
         * dual-link mode.  We do this by looking at the DT port nodes that
         * the next bridges are connected to.  If they are marked as expecting
         * even pixels and odd pixels than we need to use the companion PXL2DPI.
         */
        port1 = of_graph_get_port_by_id(p2d->bridge.next_bridge->of_node, 1);
        port2 = of_graph_get_port_by_id(companion_p2d->bridge.next_bridge->of_node, 1);
        dual_link = drm_of_lvds_get_dual_link_pixel_order(port1, port2);
        of_node_put(port1);
        of_node_put(port2);

        if (dual_link < 0) {
                ret = dual_link;
                DRM_DEV_ERROR(dev, "failed to get dual link pixel order: %d\n",
                              ret);
                goto out;
        }

        DRM_DEV_DEBUG_DRIVER(dev,
                             "dual-link configuration detected (companion bridge %pOF)\n",
                             companion);
out:
        of_node_put(companion);
        return ret;
}

static int imx8qxp_pxl2dpi_bridge_probe(struct platform_device *pdev)
{
        struct imx8qxp_pxl2dpi *p2d;
        struct device *dev = &pdev->dev;
        struct device_node *np = dev->of_node;
        int ret;

        p2d = devm_drm_bridge_alloc(dev, struct imx8qxp_pxl2dpi, bridge,
                                    &imx8qxp_pxl2dpi_bridge_funcs);
        if (IS_ERR(p2d))
                return PTR_ERR(p2d);

        p2d->regmap = syscon_node_to_regmap(np->parent);
        if (IS_ERR(p2d->regmap)) {
                ret = PTR_ERR(p2d->regmap);
                if (ret != -EPROBE_DEFER)
                        DRM_DEV_ERROR(dev, "failed to get regmap: %d\n", ret);
                return ret;
        }

        ret = imx_scu_get_handle(&p2d->ipc_handle);
        if (ret) {
                if (ret != -EPROBE_DEFER)
                        DRM_DEV_ERROR(dev, "failed to get SCU ipc handle: %d\n",
                                      ret);
                return ret;
        }

        p2d->dev = dev;

        ret = of_property_read_u32(np, "fsl,sc-resource", &p2d->sc_resource);
        if (ret) {
                DRM_DEV_ERROR(dev, "failed to get SC resource %d\n", ret);
                return ret;
        }

        ret = imx8qxp_pxl2dpi_find_next_bridge(p2d);
        if (ret)
                return ret;

        ret = imx8qxp_pxl2dpi_set_pixel_link_sel(p2d);
        if (ret)
                return ret;

        ret = imx8qxp_pxl2dpi_parse_dt_companion(p2d);
        if (ret)
                return ret;

        platform_set_drvdata(pdev, p2d);
        pm_runtime_enable(dev);

        p2d->bridge.driver_private = p2d;
        p2d->bridge.of_node = np;

        drm_bridge_add(&p2d->bridge);

        return ret;
}

static void imx8qxp_pxl2dpi_bridge_remove(struct platform_device *pdev)
{
        struct imx8qxp_pxl2dpi *p2d = platform_get_drvdata(pdev);

        drm_bridge_remove(&p2d->bridge);

        pm_runtime_disable(&pdev->dev);
}

static const struct of_device_id imx8qxp_pxl2dpi_dt_ids[] = {
        { .compatible = "fsl,imx8qxp-pxl2dpi", },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx8qxp_pxl2dpi_dt_ids);

static struct platform_driver imx8qxp_pxl2dpi_bridge_driver = {
        .probe  = imx8qxp_pxl2dpi_bridge_probe,
        .remove = imx8qxp_pxl2dpi_bridge_remove,
        .driver = {
                .of_match_table = imx8qxp_pxl2dpi_dt_ids,
                .name = DRIVER_NAME,
        },
};
module_platform_driver(imx8qxp_pxl2dpi_bridge_driver);

MODULE_DESCRIPTION("i.MX8QXP pixel link to DPI bridge driver");
MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);