hw/i2c-ddc.c: Implement DDC I2C slave

include arm-softmmu.mak

CONFIG_AUX=y

CONFIG_DDC=y

CONFIG_DPCD=y

CONFIG_XLNX_ZYNQMP=y

common-obj-y += core.o smbus.o smbus_eeprom.o

common-obj-$(CONFIG_DDC) += i2c-ddc.o

common-obj-$(CONFIG_VERSATILE_I2C) += versatile_i2c.o

common-obj-$(CONFIG_ACPI_X86) += smbus_ich9.o

common-obj-$(CONFIG_APM) += pm_smbus.o

/* A simple I2C slave for returning monitor EDID data via DDC.

 *

 * Copyright (c) 2011 Linaro Limited

 * Written by Peter Maydell

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License version 2 as

 *  published by the Free Software Foundation.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License along

 *  with this program; if not, see <http://www.gnu.org/licenses/>.

 */

#include "qemu/osdep.h"

#include "qemu/log.h"

#include "hw/i2c/i2c.h"

#include "hw/i2c/i2c-ddc.h"

#ifndef DEBUG_I2CDDC

#define DEBUG_I2CDDC 0

#endif

#define DPRINTF(fmt, ...) do {                                                 \

    if (DEBUG_I2CDDC) {                                                        \

        qemu_log("i2c-ddc: " fmt , ## __VA_ARGS__);                            \

    }                                                                          \

} while (0);

/* Structure defining a monitor's characteristics in a

 * readable format: this should be passed to build_edid_blob()

 * to convert it into the 128 byte binary EDID blob.

 * Not all bits of the EDID are customisable here.

 */

struct EDIDData {

    char manuf_id[3]; /* three upper case letters */

    uint16_t product_id;

    uint32_t serial_no;

    uint8_t manuf_week;

    int manuf_year;

    uint8_t h_cm;

    uint8_t v_cm;

    uint8_t gamma;

    char monitor_name[14];

    char serial_no_string[14];

    /* Range limits */

    uint8_t vmin; /* Hz */

    uint8_t vmax; /* Hz */

    uint8_t hmin; /* kHz */

    uint8_t hmax; /* kHz */

    uint8_t pixclock; /* MHz / 10 */

    uint8_t timing_data[18];

};

typedef struct EDIDData EDIDData;

/* EDID data for a simple LCD monitor */

static const EDIDData lcd_edid = {

    /* The manuf_id ought really to be an assigned EISA ID */

    .manuf_id = "QMU",

    .product_id = 0,

    .serial_no = 1,

    .manuf_week = 1,

    .manuf_year = 2011,

    .h_cm = 40,

    .v_cm = 30,

    .gamma = 0x78,

    .monitor_name = "QEMU monitor",

    .serial_no_string = "1",

    .vmin = 40,

    .vmax = 120,

    .hmin = 30,

    .hmax = 100,

    .pixclock = 18,

    .timing_data = {

        /* Borrowed from a 21" LCD */

        0x48, 0x3f, 0x40, 0x30, 0x62, 0xb0, 0x32, 0x40, 0x40,

        0xc0, 0x13, 0x00, 0x98, 0x32, 0x11, 0x00, 0x00, 0x1e

    }

};

static uint8_t manuf_char_to_int(char c)

{

    return (c - 'A') & 0x1f;

}

static void write_ascii_descriptor_block(uint8_t *descblob, uint8_t blocktype,

                                         const char *string)

{

    /* Write an EDID Descriptor Block of the "ascii string" type */

    int i;

    descblob[0] = descblob[1] = descblob[2] = descblob[4] = 0;

    descblob[3] = blocktype;

    /* The rest is 13 bytes of ASCII; if less then the rest must

     * be filled with newline then spaces

     */

    for (i = 5; i < 19; i++) {

        descblob[i] = string[i - 5];

        if (!descblob[i]) {

            break;

        }

    }

    if (i < 19) {

        descblob[i++] = '\n';

    }

    for ( ; i < 19; i++) {

        descblob[i] = ' ';

    }

}

static void write_range_limits_descriptor(const EDIDData *edid,

                                          uint8_t *descblob)

{

    int i;

    descblob[0] = descblob[1] = descblob[2] = descblob[4] = 0;

    descblob[3] = 0xfd;

    descblob[5] = edid->vmin;

    descblob[6] = edid->vmax;

    descblob[7] = edid->hmin;

    descblob[8] = edid->hmax;

    descblob[9] = edid->pixclock;

    descblob[10] = 0;

    descblob[11] = 0xa;

    for (i = 12; i < 19; i++) {

        descblob[i] = 0x20;

    }

}

static void build_edid_blob(const EDIDData *edid, uint8_t *blob)

{

    /* Write an EDID 1.3 format blob (128 bytes) based

     * on the EDIDData structure.

     */

    int i;

    uint8_t cksum;

    /* 00-07 : header */

    blob[0] = blob[7] = 0;

    for (i = 1 ; i < 7; i++) {

        blob[i] = 0xff;

    }

    /* 08-09 : manufacturer ID */

    blob[8] = (manuf_char_to_int(edid->manuf_id[0]) << 2)

        | (manuf_char_to_int(edid->manuf_id[1]) >> 3);

    blob[9] = (manuf_char_to_int(edid->manuf_id[1]) << 5)

        | manuf_char_to_int(edid->manuf_id[2]);

    /* 10-11 : product ID code */

    blob[10] = edid->product_id;

    blob[11] = edid->product_id >> 8;

    blob[12] = edid->serial_no;

    blob[13] = edid->serial_no >> 8;

    blob[14] = edid->serial_no >> 16;

    blob[15] = edid->serial_no >> 24;

    /* 16 : week of manufacture */

    blob[16] = edid->manuf_week;

    /* 17 : year of manufacture - 1990 */

    blob[17] = edid->manuf_year - 1990;

    /* 18, 19 : EDID version and revision */

    blob[18] = 1;

    blob[19] = 3;

    /* 20 - 24 : basic display parameters */

    /* We are always a digital display */

    blob[20] = 0x80;

    /* 21, 22 : max h/v size in cm */

    blob[21] = edid->h_cm;

    blob[22] = edid->v_cm;

    /* 23 : gamma (divide by 100 then add 1 for actual value) */

    blob[23] = edid->gamma;

    /* 24 feature support: no power management, RGB, preferred timing mode,

     * standard colour space

     */

    blob[24] = 0x0e;

    /* 25 - 34 : chromaticity coordinates. These are the

     * standard sRGB chromaticity values

     */

    blob[25] = 0xee;

    blob[26] = 0x91;

    blob[27] = 0xa3;

    blob[28] = 0x54;

    blob[29] = 0x4c;

    blob[30] = 0x99;

    blob[31] = 0x26;

    blob[32] = 0x0f;

    blob[33] = 0x50;

    blob[34] = 0x54;

    /* 35, 36 : Established timings: claim to support everything */

    blob[35] = blob[36] = 0xff;

    /* 37 : manufacturer's reserved timing: none */

    blob[37] = 0;

    /* 38 - 53 : standard timing identification

     * don't claim anything beyond what the 'established timings'

     * already provide. Unused slots must be (0x1, 0x1)

     */

    for (i = 38; i < 54; i++) {

        blob[i] = 0x1;

    }

    /* 54 - 71 : descriptor block 1 : must be preferred timing data */

    memcpy(blob + 54, edid->timing_data, 18);

    /* 72 - 89, 90 - 107, 108 - 125 : descriptor block 2, 3, 4

     * Order not important, but we must have a monitor name and a

     * range limits descriptor.

     */

    write_range_limits_descriptor(edid, blob + 72);

    write_ascii_descriptor_block(blob + 90, 0xfc, edid->monitor_name);

    write_ascii_descriptor_block(blob + 108, 0xff, edid->serial_no_string);

    /* 126 : extension flag */

    blob[126] = 0;

    cksum = 0;

    for (i = 0; i < 127; i++) {

        cksum += blob[i];

    }

    /* 127 : checksum */

    blob[127] = -cksum;

    if (DEBUG_I2CDDC) {

        qemu_hexdump((char *)blob, stdout, "", 128);

    }

}

static void i2c_ddc_reset(DeviceState *ds)

{

    I2CDDCState *s = I2CDDC(ds);

    s->firstbyte = false;

    s->reg = 0;

}

static void i2c_ddc_event(I2CSlave *i2c, enum i2c_event event)

{

    I2CDDCState *s = I2CDDC(i2c);

    if (event == I2C_START_SEND) {

        s->firstbyte = true;

    }

}

static int i2c_ddc_rx(I2CSlave *i2c)

{

    I2CDDCState *s = I2CDDC(i2c);

    int value;

    value = s->edid_blob[s->reg];

    s->reg++;

    return value;

}

static int i2c_ddc_tx(I2CSlave *i2c, uint8_t data)

{

    I2CDDCState *s = I2CDDC(i2c);

    if (s->firstbyte) {

        s->reg = data;

        s->firstbyte = false;

        DPRINTF("[EDID] Written new pointer: %u\n", data);

        return 1;

    }

    /* Ignore all writes */

    s->reg++;

    return 1;

}

static void i2c_ddc_init(Object *obj)

{

    I2CDDCState *s = I2CDDC(obj);

    build_edid_blob(&lcd_edid, s->edid_blob);

}

static const VMStateDescription vmstate_i2c_ddc = {

    .name = TYPE_I2CDDC,

    .version_id = 1,

    .fields = (VMStateField[]) {

        VMSTATE_BOOL(firstbyte, I2CDDCState),

        VMSTATE_UINT8(reg, I2CDDCState),

        VMSTATE_END_OF_LIST()

    }

};

static void i2c_ddc_class_init(ObjectClass *oc, void *data)

{

    DeviceClass *dc = DEVICE_CLASS(oc);

    I2CSlaveClass *isc = I2C_SLAVE_CLASS(oc);

    dc->reset = i2c_ddc_reset;

    dc->vmsd = &vmstate_i2c_ddc;

    isc->event = i2c_ddc_event;

    isc->recv = i2c_ddc_rx;

    isc->send = i2c_ddc_tx;

}

static TypeInfo i2c_ddc_info = {

    .name = TYPE_I2CDDC,

    .parent = TYPE_I2C_SLAVE,

    .instance_size = sizeof(I2CDDCState),

    .instance_init = i2c_ddc_init,

    .class_init = i2c_ddc_class_init

};

static void ddc_register_devices(void)

{

    type_register_static(&i2c_ddc_info);

}

type_init(ddc_register_devices);

/* A simple I2C slave for returning monitor EDID data via DDC.

 *

 * Copyright (c) 2011 Linaro Limited

 * Written by Peter Maydell

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License version 2 as

 *  published by the Free Software Foundation.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License along

 *  with this program; if not, see <http://www.gnu.org/licenses/>.

 */

#ifndef I2C_DDC

#define I2C_DDC

/* A simple I2C slave which just returns the contents of its EDID blob. */

struct I2CDDCState {

    /*< private >*/

    I2CSlave i2c;

    /*< public >*/

    bool firstbyte;

    uint8_t reg;

    uint8_t edid_blob[128];

};

typedef struct I2CDDCState I2CDDCState;

#define TYPE_I2CDDC "i2c-ddc"

#define I2CDDC(obj) OBJECT_CHECK(I2CDDCState, (obj), TYPE_I2CDDC)

#endif /* !I2C_DDC */