/*
 * Copyright (C) 2007,2008 Freescale Semiconductor, Inc. All rights reserved.
 *
 * Author: John Rigby <jrigby@freescale.com>
 *
 * Description:
 * MPC512x Shared code
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/of_platform.h>
#include <linux/fsl-diu-fb.h>
#include <linux/bootmem.h>
#include <sysdev/fsl_soc.h>

#include <asm/cacheflush.h>
#include <asm/machdep.h>
#include <asm/ipic.h>
#include <asm/prom.h>
#include <asm/time.h>
#include <asm/mpc5121.h>
#include <asm/mpc52xx_psc.h>

#include "mpc512x.h"

static struct mpc512x_reset_module __iomem *reset_module_base;

static void __init mpc512x_restart_init(void)
{
        struct device_node *np;
        const char *reset_compat;

        reset_compat = mpc512x_select_reset_compat();
        np = of_find_compatible_node(NULL, NULL, reset_compat);
        if (!np)
                return;

        reset_module_base = of_iomap(np, 0);
        of_node_put(np);
}

void mpc512x_restart(char *cmd)
{
        if (reset_module_base) {
                /* Enable software reset "RSTE" */
                out_be32(&reset_module_base->rpr, 0x52535445);
                /* Set software hard reset */
                out_be32(&reset_module_base->rcr, 0x2);
        } else {
                pr_err("Restart module not mapped.\n");
        }
        for (;;)
                ;
}

struct fsl_diu_shared_fb {
        u8              gamma[0x300];   /* 32-bit aligned! */
        struct diu_ad   ad0;            /* 32-bit aligned! */
        phys_addr_t     fb_phys;
        size_t          fb_len;
        bool            in_use;
};

#define DIU_DIV_MASK    0x000000ff
static void mpc512x_set_pixel_clock(unsigned int pixclock)
{
        unsigned long bestval, bestfreq, speed, busfreq;
        unsigned long minpixclock, maxpixclock, pixval;
        struct mpc512x_ccm __iomem *ccm;
        struct device_node *np;
        u32 temp;
        long err;
        int i;

        np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-clock");
        if (!np) {
                pr_err("Can't find clock control module.\n");
                return;
        }

        ccm = of_iomap(np, 0);
        of_node_put(np);
        if (!ccm) {
                pr_err("Can't map clock control module reg.\n");
                return;
        }

        np = of_find_node_by_type(NULL, "cpu");
        if (np) {
                const unsigned int *prop =
                        of_get_property(np, "bus-frequency", NULL);

                of_node_put(np);
                if (prop) {
                        busfreq = *prop;
                } else {
                        pr_err("Can't get bus-frequency property\n");
                        return;
                }
        } else {
                pr_err("Can't find 'cpu' node.\n");
                return;
        }

        /* Pixel Clock configuration */
        pr_debug("DIU: Bus Frequency = %lu\n", busfreq);
        speed = busfreq * 4; /* DIU_DIV ratio is 4 * CSB_CLK / DIU_CLK */

        /* Calculate the pixel clock with the smallest error */
        /* calculate the following in steps to avoid overflow */
        pr_debug("DIU pixclock in ps - %d\n", pixclock);
        temp = (1000000000 / pixclock) * 1000;
        pixclock = temp;
        pr_debug("DIU pixclock freq - %u\n", pixclock);

        temp = temp / 20; /* pixclock * 0.05 */
        pr_debug("deviation = %d\n", temp);
        minpixclock = pixclock - temp;
        maxpixclock = pixclock + temp;
        pr_debug("DIU minpixclock - %lu\n", minpixclock);
        pr_debug("DIU maxpixclock - %lu\n", maxpixclock);
        pixval = speed/pixclock;
        pr_debug("DIU pixval = %lu\n", pixval);

        err = LONG_MAX;
        bestval = pixval;
        pr_debug("DIU bestval = %lu\n", bestval);

        bestfreq = 0;
        for (i = -1; i <= 1; i++) {
                temp = speed / (pixval+i);
                pr_debug("DIU test pixval i=%d, pixval=%lu, temp freq. = %u\n",
                        i, pixval, temp);
                if ((temp < minpixclock) || (temp > maxpixclock))
                        pr_debug("DIU exceeds monitor range (%lu to %lu)\n",
                                minpixclock, maxpixclock);
                else if (abs(temp - pixclock) < err) {
                        pr_debug("Entered the else if block %d\n", i);
                        err = abs(temp - pixclock);
                        bestval = pixval + i;
                        bestfreq = temp;
                }
        }

        pr_debug("DIU chose = %lx\n", bestval);
        pr_debug("DIU error = %ld\n NomPixClk ", err);
        pr_debug("DIU: Best Freq = %lx\n", bestfreq);
        /* Modify DIU_DIV in CCM SCFR1 */
        temp = in_be32(&ccm->scfr1);
        pr_debug("DIU: Current value of SCFR1: 0x%08x\n", temp);
        temp &= ~DIU_DIV_MASK;
        temp |= (bestval & DIU_DIV_MASK);
        out_be32(&ccm->scfr1, temp);
        pr_debug("DIU: Modified value of SCFR1: 0x%08x\n", temp);
        iounmap(ccm);
}

static enum fsl_diu_monitor_port
mpc512x_valid_monitor_port(enum fsl_diu_monitor_port port)
{
        return FSL_DIU_PORT_DVI;
}

static struct fsl_diu_shared_fb __attribute__ ((__aligned__(8))) diu_shared_fb;

static inline void mpc512x_free_bootmem(struct page *page)
{
        BUG_ON(PageTail(page));
        BUG_ON(atomic_read(&page->_count) > 1);
        free_reserved_page(page);
}

static void mpc512x_release_bootmem(void)
{
        unsigned long addr = diu_shared_fb.fb_phys & PAGE_MASK;
        unsigned long size = diu_shared_fb.fb_len;
        unsigned long start, end;

        if (diu_shared_fb.in_use) {
                start = PFN_UP(addr);
                end = PFN_DOWN(addr + size);

                for (; start < end; start++)
                        mpc512x_free_bootmem(pfn_to_page(start));

                diu_shared_fb.in_use = false;
        }
        diu_ops.release_bootmem = NULL;
}

/*
 * Check if DIU was pre-initialized. If so, perform steps
 * needed to continue displaying through the whole boot process.
 * Move area descriptor and gamma table elsewhere, they are
 * destroyed by bootmem allocator otherwise. The frame buffer
 * address range will be reserved in setup_arch() after bootmem
 * allocator is up.
 */
static void __init mpc512x_init_diu(void)
{
        struct device_node *np;
        struct diu __iomem *diu_reg;
        phys_addr_t desc;
        void __iomem *vaddr;
        unsigned long mode, pix_fmt, res, bpp;
        unsigned long dst;

        np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-diu");
        if (!np) {
                pr_err("No DIU node\n");
                return;
        }

        diu_reg = of_iomap(np, 0);
        of_node_put(np);
        if (!diu_reg) {
                pr_err("Can't map DIU\n");
                return;
        }

        mode = in_be32(&diu_reg->diu_mode);
        if (mode == MFB_MODE0) {
                pr_info("%s: DIU OFF\n", __func__);
                goto out;
        }

        desc = in_be32(&diu_reg->desc[0]);
        vaddr = ioremap(desc, sizeof(struct diu_ad));
        if (!vaddr) {
                pr_err("Can't map DIU area desc.\n");
                goto out;
        }
        memcpy(&diu_shared_fb.ad0, vaddr, sizeof(struct diu_ad));
        /* flush fb area descriptor */
        dst = (unsigned long)&diu_shared_fb.ad0;
        flush_dcache_range(dst, dst + sizeof(struct diu_ad) - 1);

        res = in_be32(&diu_reg->disp_size);
        pix_fmt = in_le32(vaddr);
        bpp = ((pix_fmt >> 16) & 0x3) + 1;
        diu_shared_fb.fb_phys = in_le32(vaddr + 4);
        diu_shared_fb.fb_len = ((res & 0xfff0000) >> 16) * (res & 0xfff) * bpp;
        diu_shared_fb.in_use = true;
        iounmap(vaddr);

        desc = in_be32(&diu_reg->gamma);
        vaddr = ioremap(desc, sizeof(diu_shared_fb.gamma));
        if (!vaddr) {
                pr_err("Can't map DIU area desc.\n");
                diu_shared_fb.in_use = false;
                goto out;
        }
        memcpy(&diu_shared_fb.gamma, vaddr, sizeof(diu_shared_fb.gamma));
        /* flush gamma table */
        dst = (unsigned long)&diu_shared_fb.gamma;
        flush_dcache_range(dst, dst + sizeof(diu_shared_fb.gamma) - 1);

        iounmap(vaddr);
        out_be32(&diu_reg->gamma, virt_to_phys(&diu_shared_fb.gamma));
        out_be32(&diu_reg->desc[1], 0);
        out_be32(&diu_reg->desc[2], 0);
        out_be32(&diu_reg->desc[0], virt_to_phys(&diu_shared_fb.ad0));

out:
        iounmap(diu_reg);
}

static void __init mpc512x_setup_diu(void)
{
        int ret;

        /*
         * We do not allocate and configure new area for bitmap buffer
         * because it would requere copying bitmap data (splash image)
         * and so negatively affect boot time. Instead we reserve the
         * already configured frame buffer area so that it won't be
         * destroyed. The starting address of the area to reserve and
         * also it's length is passed to reserve_bootmem(). It will be
         * freed later on first open of fbdev, when splash image is not
         * needed any more.
         */
        if (diu_shared_fb.in_use) {
                ret = reserve_bootmem(diu_shared_fb.fb_phys,
                                      diu_shared_fb.fb_len,
                                      BOOTMEM_EXCLUSIVE);
                if (ret) {
                        pr_err("%s: reserve bootmem failed\n", __func__);
                        diu_shared_fb.in_use = false;
                }
        }

        diu_ops.set_pixel_clock         = mpc512x_set_pixel_clock;
        diu_ops.valid_monitor_port      = mpc512x_valid_monitor_port;
        diu_ops.release_bootmem         = mpc512x_release_bootmem;
}

void __init mpc512x_init_IRQ(void)
{
        struct device_node *np;

        np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-ipic");
        if (!np)
                return;

        ipic_init(np, 0);
        of_node_put(np);

        /*
         * Initialize the default interrupt mapping priorities,
         * in case the boot rom changed something on us.
         */
        ipic_set_default_priority();
}

/*
 * Nodes to do bus probe on, soc and localbus
 */
static struct of_device_id __initdata of_bus_ids[] = {
        { .compatible = "fsl,mpc5121-immr", },
        { .compatible = "fsl,mpc5121-localbus", },
        { .compatible = "fsl,mpc5121-mbx", },
        { .compatible = "fsl,mpc5121-nfc", },
        { .compatible = "fsl,mpc5121-sram", },
        { .compatible = "fsl,mpc5121-pci", },
        { .compatible = "gpio-leds", },
        {},
};

static void __init mpc512x_declare_of_platform_devices(void)
{
        if (of_platform_bus_probe(NULL, of_bus_ids, NULL))
                printk(KERN_ERR __FILE__ ": "
                        "Error while probing of_platform bus\n");
}

#define DEFAULT_FIFO_SIZE 16

const char *mpc512x_select_psc_compat(void)
{
        if (of_machine_is_compatible("fsl,mpc5121"))
                return "fsl,mpc5121-psc";

        if (of_machine_is_compatible("fsl,mpc5125"))
                return "fsl,mpc5125-psc";

        return NULL;
}

const char *mpc512x_select_reset_compat(void)
{
        if (of_machine_is_compatible("fsl,mpc5121"))
                return "fsl,mpc5121-reset";

        if (of_machine_is_compatible("fsl,mpc5125"))
                return "fsl,mpc5125-reset";

        return NULL;
}

static unsigned int __init get_fifo_size(struct device_node *np,
                                         char *prop_name)
{
        const unsigned int *fp;

        fp = of_get_property(np, prop_name, NULL);
        if (fp)
                return *fp;

        pr_warning("no %s property in %s node, defaulting to %d\n",
                   prop_name, np->full_name, DEFAULT_FIFO_SIZE);

        return DEFAULT_FIFO_SIZE;
}

#define FIFOC(_base) ((struct mpc512x_psc_fifo __iomem *) \
                    ((u32)(_base) + sizeof(struct mpc52xx_psc)))

/* Init PSC FIFO space for TX and RX slices */
static void __init mpc512x_psc_fifo_init(void)
{
        struct device_node *np;
        void __iomem *psc;
        unsigned int tx_fifo_size;
        unsigned int rx_fifo_size;
        const char *psc_compat;
        int fifobase = 0; /* current fifo address in 32 bit words */

        psc_compat = mpc512x_select_psc_compat();
        if (!psc_compat) {
                pr_err("%s: no compatible devices found\n", __func__);
                return;
        }

        for_each_compatible_node(np, NULL, psc_compat) {
                tx_fifo_size = get_fifo_size(np, "fsl,tx-fifo-size");
                rx_fifo_size = get_fifo_size(np, "fsl,rx-fifo-size");

                /* size in register is in 4 byte units */
                tx_fifo_size /= 4;
                rx_fifo_size /= 4;
                if (!tx_fifo_size)
                        tx_fifo_size = 1;
                if (!rx_fifo_size)
                        rx_fifo_size = 1;

                psc = of_iomap(np, 0);
                if (!psc) {
                        pr_err("%s: Can't map %s device\n",
                                __func__, np->full_name);
                        continue;
                }

                /* FIFO space is 4KiB, check if requested size is available */
                if ((fifobase + tx_fifo_size + rx_fifo_size) > 0x1000) {
                        pr_err("%s: no fifo space available for %s\n",
                                __func__, np->full_name);
                        iounmap(psc);
                        /*
                         * chances are that another device requests less
                         * fifo space, so we continue.
                         */
                        continue;
                }

                /* set tx and rx fifo size registers */
                out_be32(&FIFOC(psc)->txsz, (fifobase << 16) | tx_fifo_size);
                fifobase += tx_fifo_size;
                out_be32(&FIFOC(psc)->rxsz, (fifobase << 16) | rx_fifo_size);
                fifobase += rx_fifo_size;

                /* reset and enable the slices */
                out_be32(&FIFOC(psc)->txcmd, 0x80);
                out_be32(&FIFOC(psc)->txcmd, 0x01);
                out_be32(&FIFOC(psc)->rxcmd, 0x80);
                out_be32(&FIFOC(psc)->rxcmd, 0x01);

                iounmap(psc);
        }
}

void __init mpc512x_init_early(void)
{
        mpc512x_restart_init();
        if (IS_ENABLED(CONFIG_FB_FSL_DIU))
                mpc512x_init_diu();
}

void __init mpc512x_init(void)
{
        mpc5121_clk_init();
        mpc512x_declare_of_platform_devices();
        mpc512x_psc_fifo_init();
}

void __init mpc512x_setup_arch(void)
{
        if (IS_ENABLED(CONFIG_FB_FSL_DIU))
                mpc512x_setup_diu();
}

/**
 * mpc512x_cs_config - Setup chip select configuration
 * @cs: chip select number
 * @val: chip select configuration value
 *
 * Perform chip select configuration for devices on LocalPlus Bus.
 * Intended to dynamically reconfigure the chip select parameters
 * for configurable devices on the bus.
 */
int mpc512x_cs_config(unsigned int cs, u32 val)
{
        static struct mpc512x_lpc __iomem *lpc;
        struct device_node *np;

        if (cs > 7)
                return -EINVAL;

        if (!lpc) {
                np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-lpc");
                lpc = of_iomap(np, 0);
                of_node_put(np);
                if (!lpc)
                        return -ENOMEM;
        }

        out_be32(&lpc->cs_cfg[cs], val);
        return 0;
}
EXPORT_SYMBOL(mpc512x_cs_config);