// SPDX-License-Identifier: GPL-2.0-only
/*
 * Support for the camera device found on Marvell MMP processors; known
 * to work with the Armada 610 as used in the OLPC 1.75 system.
 *
 * Copyright 2011 Jonathan Corbet <corbet@lwn.net>
 * Copyright 2018 Lubomir Rintel <lkundrak@v3.sk>
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/videodev2.h>
#include <media/v4l2-device.h>
#include <linux/platform_data/media/mmp-camera.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/list.h>
#include <linux/pm.h>
#include <linux/clk.h>

#include "mcam-core.h"

MODULE_ALIAS("platform:mmp-camera");
MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
MODULE_LICENSE("GPL");

static char *mcam_clks[] = {"axi", "func", "phy"};

struct mmp_camera {
        struct platform_device *pdev;
        struct mcam_camera mcam;
        struct list_head devlist;
        struct clk *mipi_clk;
        int irq;
};

static inline struct mmp_camera *mcam_to_cam(struct mcam_camera *mcam)
{
        return container_of(mcam, struct mmp_camera, mcam);
}

/*
 * A silly little infrastructure so we can keep track of our devices.
 * Chances are that we will never have more than one of them, but
 * the Armada 610 *does* have two controllers...
 */

static LIST_HEAD(mmpcam_devices);
static struct mutex mmpcam_devices_lock;

static void mmpcam_add_device(struct mmp_camera *cam)
{
        mutex_lock(&mmpcam_devices_lock);
        list_add(&cam->devlist, &mmpcam_devices);
        mutex_unlock(&mmpcam_devices_lock);
}

static void mmpcam_remove_device(struct mmp_camera *cam)
{
        mutex_lock(&mmpcam_devices_lock);
        list_del(&cam->devlist);
        mutex_unlock(&mmpcam_devices_lock);
}

/*
 * Platform dev remove passes us a platform_device, and there's
 * no handy unused drvdata to stash a backpointer in.  So just
 * dig it out of our list.
 */
static struct mmp_camera *mmpcam_find_device(struct platform_device *pdev)
{
        struct mmp_camera *cam;

        mutex_lock(&mmpcam_devices_lock);
        list_for_each_entry(cam, &mmpcam_devices, devlist) {
                if (cam->pdev == pdev) {
                        mutex_unlock(&mmpcam_devices_lock);
                        return cam;
                }
        }
        mutex_unlock(&mmpcam_devices_lock);
        return NULL;
}

/*
 * calc the dphy register values
 * There are three dphy registers being used.
 * dphy[0] - CSI2_DPHY3
 * dphy[1] - CSI2_DPHY5
 * dphy[2] - CSI2_DPHY6
 * CSI2_DPHY3 and CSI2_DPHY6 can be set with a default value
 * or be calculated dynamically
 */
static void mmpcam_calc_dphy(struct mcam_camera *mcam)
{
        struct mmp_camera *cam = mcam_to_cam(mcam);
        struct mmp_camera_platform_data *pdata = cam->pdev->dev.platform_data;
        struct device *dev = &cam->pdev->dev;
        unsigned long tx_clk_esc;

        /*
         * If CSI2_DPHY3 is calculated dynamically,
         * pdata->lane_clk should be already set
         * either in the board driver statically
         * or in the sensor driver dynamically.
         */
        /*
         * dphy[0] - CSI2_DPHY3:
         *  bit 0 ~ bit 7: HS Term Enable.
         *   defines the time that the DPHY
         *   wait before enabling the data
         *   lane termination after detecting
         *   that the sensor has driven the data
         *   lanes to the LP00 bridge state.
         *   The value is calculated by:
         *   (Max T(D_TERM_EN)/Period(DDR)) - 1
         *  bit 8 ~ bit 15: HS_SETTLE
         *   Time interval during which the HS
         *   receiver shall ignore any Data Lane
         *   HS transitions.
         *   The value has been calibrated on
         *   different boards. It seems to work well.
         *
         *  More detail please refer
         *  MIPI Alliance Spectification for D-PHY
         *  document for explanation of HS-SETTLE
         *  and D-TERM-EN.
         */
        switch (pdata->dphy3_algo) {
        case DPHY3_ALGO_PXA910:
                /*
                 * Calculate CSI2_DPHY3 algo for PXA910
                 */
                pdata->dphy[0] =
                        (((1 + (pdata->lane_clk * 80) / 1000) & 0xff) << 8)
                        | (1 + pdata->lane_clk * 35 / 1000);
                break;
        case DPHY3_ALGO_PXA2128:
                /*
                 * Calculate CSI2_DPHY3 algo for PXA2128
                 */
                pdata->dphy[0] =
                        (((2 + (pdata->lane_clk * 110) / 1000) & 0xff) << 8)
                        | (1 + pdata->lane_clk * 35 / 1000);
                break;
        default:
                /*
                 * Use default CSI2_DPHY3 value for PXA688/PXA988
                 */
                dev_dbg(dev, "camera: use the default CSI2_DPHY3 value\n");
        }

        /*
         * mipi_clk will never be changed, it is a fixed value on MMP
         */
        if (IS_ERR(cam->mipi_clk))
                return;

        /* get the escape clk, this is hard coded */
        clk_prepare_enable(cam->mipi_clk);
        tx_clk_esc = (clk_get_rate(cam->mipi_clk) / 1000000) / 12;
        clk_disable_unprepare(cam->mipi_clk);
        /*
         * dphy[2] - CSI2_DPHY6:
         * bit 0 ~ bit 7: CK Term Enable
         *  Time for the Clock Lane receiver to enable the HS line
         *  termination. The value is calculated similarly with
         *  HS Term Enable
         * bit 8 ~ bit 15: CK Settle
         *  Time interval during which the HS receiver shall ignore
         *  any Clock Lane HS transitions.
         *  The value is calibrated on the boards.
         */
        pdata->dphy[2] =
                ((((534 * tx_clk_esc) / 2000 - 1) & 0xff) << 8)
                | (((38 * tx_clk_esc) / 1000 - 1) & 0xff);

        dev_dbg(dev, "camera: DPHY sets: dphy3=0x%x, dphy5=0x%x, dphy6=0x%x\n",
                pdata->dphy[0], pdata->dphy[1], pdata->dphy[2]);
}

static irqreturn_t mmpcam_irq(int irq, void *data)
{
        struct mcam_camera *mcam = data;
        unsigned int irqs, handled;

        spin_lock(&mcam->dev_lock);
        irqs = mcam_reg_read(mcam, REG_IRQSTAT);
        handled = mccic_irq(mcam, irqs);
        spin_unlock(&mcam->dev_lock);
        return IRQ_RETVAL(handled);
}

static void mcam_init_clk(struct mcam_camera *mcam)
{
        unsigned int i;

        for (i = 0; i < NR_MCAM_CLK; i++) {
                if (mcam_clks[i] != NULL) {
                        /* Some clks are not necessary on some boards
                         * We still try to run even it fails getting clk
                         */
                        mcam->clk[i] = devm_clk_get(mcam->dev, mcam_clks[i]);
                        if (IS_ERR(mcam->clk[i]))
                                dev_warn(mcam->dev, "Could not get clk: %s\n",
                                                mcam_clks[i]);
                }
        }
}

static int mmpcam_probe(struct platform_device *pdev)
{
        struct mmp_camera *cam;
        struct mcam_camera *mcam;
        struct resource *res;
        struct fwnode_handle *ep;
        struct mmp_camera_platform_data *pdata;
        int ret;

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

        mcam = &cam->mcam;
        mcam->calc_dphy = mmpcam_calc_dphy;
        mcam->dev = &pdev->dev;
        pdata = pdev->dev.platform_data;
        if (pdata) {
                mcam->mclk_src = pdata->mclk_src;
                mcam->mclk_div = pdata->mclk_div;
                mcam->bus_type = pdata->bus_type;
                mcam->dphy = pdata->dphy;
                mcam->lane = pdata->lane;
        } else {
                /*
                 * These are values that used to be hardcoded in mcam-core and
                 * work well on a OLPC XO 1.75 with a parallel bus sensor.
                 * If it turns out other setups make sense, the values should
                 * be obtained from the device tree.
                 */
                mcam->mclk_src = 3;
                mcam->mclk_div = 2;
        }
        if (mcam->bus_type == V4L2_MBUS_CSI2_DPHY) {
                cam->mipi_clk = devm_clk_get(mcam->dev, "mipi");
                if ((IS_ERR(cam->mipi_clk) && mcam->dphy[2] == 0))
                        return PTR_ERR(cam->mipi_clk);
        }
        mcam->mipi_enabled = false;
        mcam->chip_id = MCAM_ARMADA610;
        mcam->buffer_mode = B_DMA_sg;
        strscpy(mcam->bus_info, "platform:mmp-camera", sizeof(mcam->bus_info));
        spin_lock_init(&mcam->dev_lock);
        /*
         * Get our I/O memory.
         */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        mcam->regs = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(mcam->regs))
                return PTR_ERR(mcam->regs);
        mcam->regs_size = resource_size(res);

        mcam_init_clk(mcam);

        /*
         * Create a match of the sensor against its OF node.
         */
        ep = fwnode_graph_get_next_endpoint(of_fwnode_handle(pdev->dev.of_node),
                                            NULL);
        if (!ep)
                return -ENODEV;

        mcam->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
        mcam->asd.match.fwnode = fwnode_graph_get_remote_port_parent(ep);

        fwnode_handle_put(ep);

        /*
         * Register the device with the core.
         */
        ret = mccic_register(mcam);
        if (ret)
                return ret;

        /*
         * Add OF clock provider.
         */
        ret = of_clk_add_provider(pdev->dev.of_node, of_clk_src_simple_get,
                                                                mcam->mclk);
        if (ret) {
                dev_err(&pdev->dev, "can't add DT clock provider\n");
                goto out;
        }

        /*
         * Finally, set up our IRQ now that the core is ready to
         * deal with it.
         */
        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        if (res == NULL) {
                ret = -ENODEV;
                goto out;
        }
        cam->irq = res->start;
        ret = devm_request_irq(&pdev->dev, cam->irq, mmpcam_irq, IRQF_SHARED,
                                        "mmp-camera", mcam);
        if (ret == 0) {
                mmpcam_add_device(cam);
                return 0;
        }

out:
        fwnode_handle_put(mcam->asd.match.fwnode);
        mccic_shutdown(mcam);

        return ret;
}


static int mmpcam_remove(struct mmp_camera *cam)
{
        struct mcam_camera *mcam = &cam->mcam;

        mmpcam_remove_device(cam);
        mccic_shutdown(mcam);
        return 0;
}

static int mmpcam_platform_remove(struct platform_device *pdev)
{
        struct mmp_camera *cam = mmpcam_find_device(pdev);

        if (cam == NULL)
                return -ENODEV;
        return mmpcam_remove(cam);
}

/*
 * Suspend/resume support.
 */
#ifdef CONFIG_PM

static int mmpcam_suspend(struct platform_device *pdev, pm_message_t state)
{
        struct mmp_camera *cam = mmpcam_find_device(pdev);

        if (state.event != PM_EVENT_SUSPEND)
                return 0;
        mccic_suspend(&cam->mcam);
        return 0;
}

static int mmpcam_resume(struct platform_device *pdev)
{
        struct mmp_camera *cam = mmpcam_find_device(pdev);

        return mccic_resume(&cam->mcam);
}

#endif

static const struct of_device_id mmpcam_of_match[] = {
        { .compatible = "marvell,mmp2-ccic", },
        {},
};
MODULE_DEVICE_TABLE(of, mmpcam_of_match);

static struct platform_driver mmpcam_driver = {
        .probe          = mmpcam_probe,
        .remove         = mmpcam_platform_remove,
#ifdef CONFIG_PM
        .suspend        = mmpcam_suspend,
        .resume         = mmpcam_resume,
#endif
        .driver = {
                .name   = "mmp-camera",
                .of_match_table = of_match_ptr(mmpcam_of_match),
        }
};


static int __init mmpcam_init_module(void)
{
        mutex_init(&mmpcam_devices_lock);
        return platform_driver_register(&mmpcam_driver);
}

static void __exit mmpcam_exit_module(void)
{
        platform_driver_unregister(&mmpcam_driver);
        /*
         * platform_driver_unregister() should have emptied the list
         */
        if (!list_empty(&mmpcam_devices))
                printk(KERN_ERR "mmp_camera leaving devices behind\n");
}

module_init(mmpcam_init_module);
module_exit(mmpcam_exit_module);