// SPDX-License-Identifier: GPL-2.0
#include "radeonfb.h"

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/fb.h>


#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>

#include <asm/io.h>

#include <video/radeon.h>
#include "../edid.h"

static void radeon_gpio_setscl(void* data, int state)
{
        struct radeon_i2c_chan  *chan = data;
        struct radeonfb_info    *rinfo = chan->rinfo;
        u32                     val;
        
        val = INREG(chan->ddc_reg) & ~(VGA_DDC_CLK_OUT_EN);
        if (!state)
                val |= VGA_DDC_CLK_OUT_EN;

        OUTREG(chan->ddc_reg, val);
        (void)INREG(chan->ddc_reg);
}

static void radeon_gpio_setsda(void* data, int state)
{
        struct radeon_i2c_chan  *chan = data;
        struct radeonfb_info    *rinfo = chan->rinfo;
        u32                     val;
        
        val = INREG(chan->ddc_reg) & ~(VGA_DDC_DATA_OUT_EN);
        if (!state)
                val |= VGA_DDC_DATA_OUT_EN;

        OUTREG(chan->ddc_reg, val);
        (void)INREG(chan->ddc_reg);
}

static int radeon_gpio_getscl(void* data)
{
        struct radeon_i2c_chan  *chan = data;
        struct radeonfb_info    *rinfo = chan->rinfo;
        u32                     val;
        
        val = INREG(chan->ddc_reg);

        return (val & VGA_DDC_CLK_INPUT) ? 1 : 0;
}

static int radeon_gpio_getsda(void* data)
{
        struct radeon_i2c_chan  *chan = data;
        struct radeonfb_info    *rinfo = chan->rinfo;
        u32                     val;
        
        val = INREG(chan->ddc_reg);

        return (val & VGA_DDC_DATA_INPUT) ? 1 : 0;
}

static int radeon_setup_i2c_bus(struct radeon_i2c_chan *chan, const char *name)
{
        int rc;

        snprintf(chan->adapter.name, sizeof(chan->adapter.name),
                 "radeonfb %s", name);
        chan->adapter.owner             = THIS_MODULE;
        chan->adapter.algo_data         = &chan->algo;
        chan->adapter.dev.parent        = &chan->rinfo->pdev->dev;
        chan->algo.setsda               = radeon_gpio_setsda;
        chan->algo.setscl               = radeon_gpio_setscl;
        chan->algo.getsda               = radeon_gpio_getsda;
        chan->algo.getscl               = radeon_gpio_getscl;
        chan->algo.udelay               = 10;
        chan->algo.timeout              = 20;
        chan->algo.data                 = chan; 
        
        i2c_set_adapdata(&chan->adapter, chan);
        
        /* Raise SCL and SDA */
        radeon_gpio_setsda(chan, 1);
        radeon_gpio_setscl(chan, 1);
        udelay(20);

        rc = i2c_bit_add_bus(&chan->adapter);
        if (rc == 0)
                dev_dbg(&chan->rinfo->pdev->dev, "I2C bus %s registered.\n", name);
        else
                dev_warn(&chan->rinfo->pdev->dev, "Failed to register I2C bus %s.\n", name);
        return rc;
}

void radeon_create_i2c_busses(struct radeonfb_info *rinfo)
{
        rinfo->i2c[0].rinfo     = rinfo;
        rinfo->i2c[0].ddc_reg   = GPIO_MONID;
#ifndef CONFIG_PPC
        rinfo->i2c[0].adapter.class = I2C_CLASS_HWMON;
#endif
        radeon_setup_i2c_bus(&rinfo->i2c[0], "monid");

        rinfo->i2c[1].rinfo     = rinfo;
        rinfo->i2c[1].ddc_reg   = GPIO_DVI_DDC;
        radeon_setup_i2c_bus(&rinfo->i2c[1], "dvi");

        rinfo->i2c[2].rinfo     = rinfo;
        rinfo->i2c[2].ddc_reg   = GPIO_VGA_DDC;
        radeon_setup_i2c_bus(&rinfo->i2c[2], "vga");

        rinfo->i2c[3].rinfo     = rinfo;
        rinfo->i2c[3].ddc_reg   = GPIO_CRT2_DDC;
        radeon_setup_i2c_bus(&rinfo->i2c[3], "crt2");
}

void radeon_delete_i2c_busses(struct radeonfb_info *rinfo)
{
        if (rinfo->i2c[0].rinfo)
                i2c_del_adapter(&rinfo->i2c[0].adapter);
        rinfo->i2c[0].rinfo = NULL;

        if (rinfo->i2c[1].rinfo)
                i2c_del_adapter(&rinfo->i2c[1].adapter);
        rinfo->i2c[1].rinfo = NULL;

        if (rinfo->i2c[2].rinfo)
                i2c_del_adapter(&rinfo->i2c[2].adapter);
        rinfo->i2c[2].rinfo = NULL;

        if (rinfo->i2c[3].rinfo)
                i2c_del_adapter(&rinfo->i2c[3].adapter);
        rinfo->i2c[3].rinfo = NULL;
}

int radeon_probe_i2c_connector(struct radeonfb_info *rinfo, int conn,
                               u8 **out_edid)
{
        u8 *edid;

        edid = fb_ddc_read(&rinfo->i2c[conn-1].adapter);

        if (out_edid)
                *out_edid = edid;
        if (!edid) {
                pr_debug("radeonfb: I2C (port %d) ... not found\n", conn);
                return MT_NONE;
        }
        if (edid[0x14] & 0x80) {
                /* Fix detection using BIOS tables */
                if (rinfo->is_mobility /*&& conn == ddc_dvi*/ &&
                    (INREG(LVDS_GEN_CNTL) & LVDS_ON)) {
                        pr_debug("radeonfb: I2C (port %d) ... found LVDS panel\n", conn);
                        return MT_LCD;
                } else {
                        pr_debug("radeonfb: I2C (port %d) ... found TMDS panel\n", conn);
                        return MT_DFP;
                }
        }
        pr_debug("radeonfb: I2C (port %d) ... found CRT display\n", conn);
        return MT_CRT;
}