root/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) 2011-2018 Magewell Electronics Co., Ltd. (Nanjing)
 * Author: Yong Deng <yong.deng@magewell.com>
 * Copyright 2021-2022 Bootlin
 * Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <media/v4l2-device.h>
#include <media/v4l2-mc.h>

#include "sun6i_csi.h"
#include "sun6i_csi_bridge.h"
#include "sun6i_csi_capture.h"
#include "sun6i_csi_reg.h"

/* ISP */

int sun6i_csi_isp_complete(struct sun6i_csi_device *csi_dev,
                           struct v4l2_device *v4l2_dev)
{
        if (csi_dev->v4l2_dev && csi_dev->v4l2_dev != v4l2_dev)
                return -EINVAL;

        csi_dev->v4l2_dev = v4l2_dev;
        csi_dev->media_dev = v4l2_dev->mdev;

        return sun6i_csi_capture_setup(csi_dev);
}

static int sun6i_csi_isp_detect(struct sun6i_csi_device *csi_dev)
{
        struct device *dev = csi_dev->dev;
        struct fwnode_handle *handle;

        /*
         * ISP is not available if not connected via fwnode graph.
         * This will also check that the remote parent node is available.
         */
        handle = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev),
                                                 SUN6I_CSI_PORT_ISP, 0,
                                                 FWNODE_GRAPH_ENDPOINT_NEXT);
        if (!handle)
                return 0;

        fwnode_handle_put(handle);

        if (!IS_ENABLED(CONFIG_VIDEO_SUN6I_ISP)) {
                dev_warn(dev,
                         "ISP link is detected but not enabled in kernel config!");
                return 0;
        }

        csi_dev->isp_available = true;

        return 0;
}

/* Media */

static const struct media_device_ops sun6i_csi_media_ops = {
        .link_notify = v4l2_pipeline_link_notify,
};

/* V4L2 */

static int sun6i_csi_v4l2_setup(struct sun6i_csi_device *csi_dev)
{
        struct sun6i_csi_v4l2 *v4l2 = &csi_dev->v4l2;
        struct media_device *media_dev = &v4l2->media_dev;
        struct v4l2_device *v4l2_dev = &v4l2->v4l2_dev;
        struct device *dev = csi_dev->dev;
        int ret;

        /* Media Device */

        strscpy(media_dev->model, SUN6I_CSI_DESCRIPTION,
                sizeof(media_dev->model));
        media_dev->hw_revision = 0;
        media_dev->ops = &sun6i_csi_media_ops;
        media_dev->dev = dev;

        media_device_init(media_dev);

        ret = media_device_register(media_dev);
        if (ret) {
                dev_err(dev, "failed to register media device: %d\n", ret);
                goto error_media;
        }

        /* V4L2 Device */

        v4l2_dev->mdev = media_dev;

        ret = v4l2_device_register(dev, v4l2_dev);
        if (ret) {
                dev_err(dev, "failed to register v4l2 device: %d\n", ret);
                goto error_media;
        }

        csi_dev->v4l2_dev = v4l2_dev;
        csi_dev->media_dev = media_dev;

        return 0;

error_media:
        media_device_unregister(media_dev);
        media_device_cleanup(media_dev);

        return ret;
}

static void sun6i_csi_v4l2_cleanup(struct sun6i_csi_device *csi_dev)
{
        struct sun6i_csi_v4l2 *v4l2 = &csi_dev->v4l2;

        media_device_unregister(&v4l2->media_dev);
        v4l2_device_unregister(&v4l2->v4l2_dev);
        media_device_cleanup(&v4l2->media_dev);
}

/* Platform */

static irqreturn_t sun6i_csi_interrupt(int irq, void *private)
{
        struct sun6i_csi_device *csi_dev = private;
        bool capture_streaming = csi_dev->capture.state.streaming;
        struct regmap *regmap = csi_dev->regmap;
        u32 status = 0, enable = 0;

        regmap_read(regmap, SUN6I_CSI_CH_INT_STA_REG, &status);
        regmap_read(regmap, SUN6I_CSI_CH_INT_EN_REG, &enable);

        if (!status)
                return IRQ_NONE;
        else if (!(status & enable) || !capture_streaming)
                goto complete;

        if ((status & SUN6I_CSI_CH_INT_STA_FIFO0_OF) ||
            (status & SUN6I_CSI_CH_INT_STA_FIFO1_OF) ||
            (status & SUN6I_CSI_CH_INT_STA_FIFO2_OF) ||
            (status & SUN6I_CSI_CH_INT_STA_HB_OF)) {
                regmap_write(regmap, SUN6I_CSI_CH_INT_STA_REG, status);

                regmap_update_bits(regmap, SUN6I_CSI_EN_REG,
                                   SUN6I_CSI_EN_CSI_EN, 0);
                regmap_update_bits(regmap, SUN6I_CSI_EN_REG,
                                   SUN6I_CSI_EN_CSI_EN, SUN6I_CSI_EN_CSI_EN);
                return IRQ_HANDLED;
        }

        if (status & SUN6I_CSI_CH_INT_STA_FD)
                sun6i_csi_capture_frame_done(csi_dev);

        if (status & SUN6I_CSI_CH_INT_STA_VS)
                sun6i_csi_capture_sync(csi_dev);

complete:
        regmap_write(regmap, SUN6I_CSI_CH_INT_STA_REG, status);

        return IRQ_HANDLED;
}

static int sun6i_csi_suspend(struct device *dev)
{
        struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);

        reset_control_assert(csi_dev->reset);
        clk_disable_unprepare(csi_dev->clock_ram);
        clk_disable_unprepare(csi_dev->clock_mod);

        return 0;
}

static int sun6i_csi_resume(struct device *dev)
{
        struct sun6i_csi_device *csi_dev = dev_get_drvdata(dev);
        int ret;

        ret = reset_control_deassert(csi_dev->reset);
        if (ret) {
                dev_err(dev, "failed to deassert reset\n");
                return ret;
        }

        ret = clk_prepare_enable(csi_dev->clock_mod);
        if (ret) {
                dev_err(dev, "failed to enable module clock\n");
                goto error_reset;
        }

        ret = clk_prepare_enable(csi_dev->clock_ram);
        if (ret) {
                dev_err(dev, "failed to enable ram clock\n");
                goto error_clock_mod;
        }

        return 0;

error_clock_mod:
        clk_disable_unprepare(csi_dev->clock_mod);

error_reset:
        reset_control_assert(csi_dev->reset);

        return ret;
}

static const struct dev_pm_ops sun6i_csi_pm_ops = {
        .runtime_suspend        = sun6i_csi_suspend,
        .runtime_resume         = sun6i_csi_resume,
};

static const struct regmap_config sun6i_csi_regmap_config = {
        .reg_bits       = 32,
        .reg_stride     = 4,
        .val_bits       = 32,
        .max_register   = 0x9c,
};

static int sun6i_csi_resources_setup(struct sun6i_csi_device *csi_dev,
                                     struct platform_device *platform_dev)
{
        struct device *dev = csi_dev->dev;
        const struct sun6i_csi_variant *variant;
        void __iomem *io_base;
        int ret;
        int irq;

        variant = of_device_get_match_data(dev);
        if (!variant)
                return -EINVAL;

        /* Registers */

        io_base = devm_platform_ioremap_resource(platform_dev, 0);
        if (IS_ERR(io_base))
                return PTR_ERR(io_base);

        csi_dev->regmap = devm_regmap_init_mmio_clk(dev, "bus", io_base,
                                                    &sun6i_csi_regmap_config);
        if (IS_ERR(csi_dev->regmap)) {
                dev_err(dev, "failed to init register map\n");
                return PTR_ERR(csi_dev->regmap);
        }

        /* Clocks */

        csi_dev->clock_mod = devm_clk_get(dev, "mod");
        if (IS_ERR(csi_dev->clock_mod)) {
                dev_err(dev, "failed to acquire module clock\n");
                return PTR_ERR(csi_dev->clock_mod);
        }

        csi_dev->clock_ram = devm_clk_get(dev, "ram");
        if (IS_ERR(csi_dev->clock_ram)) {
                dev_err(dev, "failed to acquire ram clock\n");
                return PTR_ERR(csi_dev->clock_ram);
        }

        ret = clk_set_rate_exclusive(csi_dev->clock_mod,
                                     variant->clock_mod_rate);
        if (ret) {
                dev_err(dev, "failed to set mod clock rate\n");
                return ret;
        }

        /* Reset */

        csi_dev->reset = devm_reset_control_get_shared(dev, NULL);
        if (IS_ERR(csi_dev->reset)) {
                dev_err(dev, "failed to acquire reset\n");
                ret = PTR_ERR(csi_dev->reset);
                goto error_clock_rate_exclusive;
        }

        /* Interrupt */

        irq = platform_get_irq(platform_dev, 0);
        if (irq < 0) {
                ret = -ENXIO;
                goto error_clock_rate_exclusive;
        }

        ret = devm_request_irq(dev, irq, sun6i_csi_interrupt, IRQF_SHARED,
                               SUN6I_CSI_NAME, csi_dev);
        if (ret) {
                dev_err(dev, "failed to request interrupt\n");
                goto error_clock_rate_exclusive;
        }

        /* Runtime PM */

        pm_runtime_enable(dev);

        return 0;

error_clock_rate_exclusive:
        clk_rate_exclusive_put(csi_dev->clock_mod);

        return ret;
}

static void sun6i_csi_resources_cleanup(struct sun6i_csi_device *csi_dev)
{
        pm_runtime_disable(csi_dev->dev);
        clk_rate_exclusive_put(csi_dev->clock_mod);
}

static int sun6i_csi_probe(struct platform_device *platform_dev)
{
        struct sun6i_csi_device *csi_dev;
        struct device *dev = &platform_dev->dev;
        int ret;

        csi_dev = devm_kzalloc(dev, sizeof(*csi_dev), GFP_KERNEL);
        if (!csi_dev)
                return -ENOMEM;

        csi_dev->dev = &platform_dev->dev;
        platform_set_drvdata(platform_dev, csi_dev);

        ret = sun6i_csi_resources_setup(csi_dev, platform_dev);
        if (ret)
                return ret;

        ret = sun6i_csi_isp_detect(csi_dev);
        if (ret)
                goto error_resources;

        /*
         * Register our own v4l2 and media devices when there is no ISP around.
         * Otherwise the ISP will use async subdev registration with our bridge,
         * which will provide v4l2 and media devices that are used to register
         * the video interface.
         */
        if (!csi_dev->isp_available) {
                ret = sun6i_csi_v4l2_setup(csi_dev);
                if (ret)
                        goto error_resources;
        }

        ret = sun6i_csi_bridge_setup(csi_dev);
        if (ret)
                goto error_v4l2;

        if (!csi_dev->isp_available) {
                ret = sun6i_csi_capture_setup(csi_dev);
                if (ret)
                        goto error_bridge;
        }

        return 0;

error_bridge:
        sun6i_csi_bridge_cleanup(csi_dev);

error_v4l2:
        if (!csi_dev->isp_available)
                sun6i_csi_v4l2_cleanup(csi_dev);

error_resources:
        sun6i_csi_resources_cleanup(csi_dev);

        return ret;
}

static void sun6i_csi_remove(struct platform_device *pdev)
{
        struct sun6i_csi_device *csi_dev = platform_get_drvdata(pdev);

        sun6i_csi_capture_cleanup(csi_dev);
        sun6i_csi_bridge_cleanup(csi_dev);

        if (!csi_dev->isp_available)
                sun6i_csi_v4l2_cleanup(csi_dev);

        sun6i_csi_resources_cleanup(csi_dev);
}

static const struct sun6i_csi_variant sun6i_a31_csi_variant = {
        .clock_mod_rate = 297000000,
};

static const struct sun6i_csi_variant sun50i_a64_csi_variant = {
        .clock_mod_rate = 300000000,
};

static const struct of_device_id sun6i_csi_of_match[] = {
        {
                .compatible     = "allwinner,sun6i-a31-csi",
                .data           = &sun6i_a31_csi_variant,
        },
        {
                .compatible     = "allwinner,sun8i-a83t-csi",
                .data           = &sun6i_a31_csi_variant,
        },
        {
                .compatible     = "allwinner,sun8i-h3-csi",
                .data           = &sun6i_a31_csi_variant,
        },
        {
                .compatible     = "allwinner,sun8i-v3s-csi",
                .data           = &sun6i_a31_csi_variant,
        },
        {
                .compatible     = "allwinner,sun50i-a64-csi",
                .data           = &sun50i_a64_csi_variant,
        },
        {},
};

MODULE_DEVICE_TABLE(of, sun6i_csi_of_match);

static struct platform_driver sun6i_csi_platform_driver = {
        .probe  = sun6i_csi_probe,
        .remove = sun6i_csi_remove,
        .driver = {
                .name           = SUN6I_CSI_NAME,
                .of_match_table = sun6i_csi_of_match,
                .pm             = &sun6i_csi_pm_ops,
        },
};

module_platform_driver(sun6i_csi_platform_driver);

MODULE_DESCRIPTION("Allwinner A31 Camera Sensor Interface driver");
MODULE_AUTHOR("Yong Deng <yong.deng@magewell.com>");
MODULE_AUTHOR("Paul Kocialkowski <paul.kocialkowski@bootlin.com>");
MODULE_LICENSE("GPL");