// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * Hardware accelerated Matrox Millennium I, II, Mystique, G100, G200, G400 and G450.
 *
 * (c) 1998-2002 Petr Vandrovec <vandrove@vc.cvut.cz>
 *
 * Version: 1.64 2002/06/10
 *
 * See matroxfb_base.c for contributors.
 *
 */

#include "matroxfb_base.h"
#include "matroxfb_maven.h"
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/i2c-algo-bit.h>

/* MGA-TVO I2C for G200, G400 */
#define MAT_CLK         0x20
#define MAT_DATA        0x10
/* primary head DDC for Mystique(?), G100, G200, G400 */
#define DDC1_CLK        0x08
#define DDC1_DATA       0x02
/* primary head DDC for Millennium, Millennium II */
#define DDC1B_CLK       0x10
#define DDC1B_DATA      0x04
/* secondary head DDC for G400 */
#define DDC2_CLK        0x04
#define DDC2_DATA       0x01

/******************************************************/

struct matroxfb_dh_maven_info {
        struct i2c_bit_adapter  maven;
        struct i2c_bit_adapter  ddc1;
        struct i2c_bit_adapter  ddc2;
};

static int matroxfb_read_gpio(struct matrox_fb_info* minfo) {
        unsigned long flags;
        int v;

        matroxfb_DAC_lock_irqsave(flags);
        v = matroxfb_DAC_in(minfo, DAC_XGENIODATA);
        matroxfb_DAC_unlock_irqrestore(flags);
        return v;
}

static void matroxfb_set_gpio(struct matrox_fb_info* minfo, int mask, int val) {
        unsigned long flags;
        int v;

        matroxfb_DAC_lock_irqsave(flags);
        v = (matroxfb_DAC_in(minfo, DAC_XGENIOCTRL) & mask) | val;
        matroxfb_DAC_out(minfo, DAC_XGENIOCTRL, v);
        /* We must reset GENIODATA very often... XFree plays with this register */
        matroxfb_DAC_out(minfo, DAC_XGENIODATA, 0x00);
        matroxfb_DAC_unlock_irqrestore(flags);
}

/* software I2C functions */
static inline void matroxfb_i2c_set(struct matrox_fb_info* minfo, int mask, int state) {
        if (state)
                state = 0;
        else
                state = mask;
        matroxfb_set_gpio(minfo, ~mask, state);
}

static void matroxfb_gpio_setsda(void* data, int state) {
        struct i2c_bit_adapter* b = data;
        matroxfb_i2c_set(b->minfo, b->mask.data, state);
}

static void matroxfb_gpio_setscl(void* data, int state) {
        struct i2c_bit_adapter* b = data;
        matroxfb_i2c_set(b->minfo, b->mask.clock, state);
}

static int matroxfb_gpio_getsda(void* data) {
        struct i2c_bit_adapter* b = data;
        return (matroxfb_read_gpio(b->minfo) & b->mask.data) ? 1 : 0;
}

static int matroxfb_gpio_getscl(void* data) {
        struct i2c_bit_adapter* b = data;
        return (matroxfb_read_gpio(b->minfo) & b->mask.clock) ? 1 : 0;
}

static const struct i2c_algo_bit_data matrox_i2c_algo_template =
{
        .setsda         = matroxfb_gpio_setsda,
        .setscl         = matroxfb_gpio_setscl,
        .getsda         = matroxfb_gpio_getsda,
        .getscl         = matroxfb_gpio_getscl,
        .udelay         = 10,
        .timeout        = 100,
};

static int i2c_bus_reg(struct i2c_bit_adapter* b, struct matrox_fb_info* minfo, 
                unsigned int data, unsigned int clock, const char *name)
{
        int err;

        b->minfo = minfo;
        b->mask.data = data;
        b->mask.clock = clock;
        b->adapter.owner = THIS_MODULE;
        snprintf(b->adapter.name, sizeof(b->adapter.name), name,
                minfo->fbcon.node);
        i2c_set_adapdata(&b->adapter, b);
        b->adapter.algo_data = &b->bac;
        b->adapter.dev.parent = &minfo->pcidev->dev;
        b->bac = matrox_i2c_algo_template;
        b->bac.data = b;
        err = i2c_bit_add_bus(&b->adapter);
        b->initialized = !err;
        return err;
}

static void i2c_bit_bus_del(struct i2c_bit_adapter* b) {
        if (b->initialized) {
                i2c_del_adapter(&b->adapter);
                b->initialized = 0;
        }
}

static inline void i2c_maven_done(struct matroxfb_dh_maven_info* minfo2) {
        i2c_bit_bus_del(&minfo2->maven);
}

static inline void i2c_ddc1_done(struct matroxfb_dh_maven_info* minfo2) {
        i2c_bit_bus_del(&minfo2->ddc1);
}

static inline void i2c_ddc2_done(struct matroxfb_dh_maven_info* minfo2) {
        i2c_bit_bus_del(&minfo2->ddc2);
}

static void* i2c_matroxfb_probe(struct matrox_fb_info* minfo) {
        int err;
        unsigned long flags;
        struct matroxfb_dh_maven_info* m2info;

        m2info = kzalloc_obj(*m2info);
        if (!m2info)
                return NULL;

        matroxfb_DAC_lock_irqsave(flags);
        matroxfb_DAC_out(minfo, DAC_XGENIODATA, 0xFF);
        matroxfb_DAC_out(minfo, DAC_XGENIOCTRL, 0x00);
        matroxfb_DAC_unlock_irqrestore(flags);

        switch (minfo->chip) {
                case MGA_2064:
                case MGA_2164:
                        err = i2c_bus_reg(&m2info->ddc1, minfo,
                                          DDC1B_DATA, DDC1B_CLK,
                                          "DDC:fb%u #0");
                        break;
                default:
                        err = i2c_bus_reg(&m2info->ddc1, minfo,
                                          DDC1_DATA, DDC1_CLK,
                                          "DDC:fb%u #0");
                        break;
        }
        if (err)
                goto fail_ddc1;
        if (minfo->devflags.dualhead) {
                err = i2c_bus_reg(&m2info->ddc2, minfo, DDC2_DATA, DDC2_CLK, "DDC:fb%u #1");
                if (err == -ENODEV) {
                        printk(KERN_INFO "i2c-matroxfb: VGA->TV plug detected, DDC unavailable.\n");
                } else if (err)
                        printk(KERN_INFO "i2c-matroxfb: Could not register secondary output i2c bus. Continuing anyway.\n");
                /* Register maven bus even on G450/G550 */
                err = i2c_bus_reg(&m2info->maven, minfo, MAT_DATA, MAT_CLK, "MAVEN:fb%u");
                if (err)
                        printk(KERN_INFO "i2c-matroxfb: Could not register Maven i2c bus. Continuing anyway.\n");
                else {
                        struct i2c_board_info maven_info = {
                                I2C_BOARD_INFO("maven", 0x1b),
                        };
                        unsigned short const addr_list[2] = {
                                0x1b, I2C_CLIENT_END
                        };

                        i2c_new_scanned_device(&m2info->maven.adapter,
                                               &maven_info, addr_list, NULL);
                }
        }
        return m2info;
fail_ddc1:;
        kfree(m2info);
        printk(KERN_ERR "i2c-matroxfb: Could not register primary adapter DDC bus.\n");
        return NULL;
}

static void i2c_matroxfb_remove(struct matrox_fb_info* minfo, void* data) {
        struct matroxfb_dh_maven_info* m2info = data;

        i2c_maven_done(m2info);
        i2c_ddc2_done(m2info);
        i2c_ddc1_done(m2info);
        kfree(m2info);
}

static struct matroxfb_driver i2c_matroxfb = {
        .node =         LIST_HEAD_INIT(i2c_matroxfb.node),
        .name =         "i2c-matroxfb",
        .probe =        i2c_matroxfb_probe,
        .remove =       i2c_matroxfb_remove,
};

static int __init i2c_matroxfb_init(void) {
        if (matroxfb_register_driver(&i2c_matroxfb)) {
                printk(KERN_ERR "i2c-matroxfb: failed to register driver\n");
                return -ENXIO;
        }
        return 0;
}

static void __exit i2c_matroxfb_exit(void) {
        matroxfb_unregister_driver(&i2c_matroxfb);
}

MODULE_AUTHOR("(c) 1999-2002 Petr Vandrovec <vandrove@vc.cvut.cz>");
MODULE_DESCRIPTION("Support module providing I2C buses present on Matrox videocards");

module_init(i2c_matroxfb_init);
module_exit(i2c_matroxfb_exit);
/* no __setup required */
MODULE_LICENSE("GPL");