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authorPeter Maydell <peter.maydell@linaro.org>2012-07-04 11:18:48 +0000
committerPeter Maydell <peter.maydell@linaro.org>2012-08-06 15:51:41 +0100
commitd01f2caa22071e01e278c83b56740906c7e51446 (patch)
tree295a441e74d764d6fc3f1513dbe2a7660f551d0a
parentc5724aba27c1f2f450b5bd6cc9d063b1e5e6474e (diff)
downloadqemu-arm-d01f2caa22071e01e278c83b56740906c7e51446.tar.gz
hw/i2c-ddc.c: Implement DDC I2C slave
Implement an I2C slave which implements DDC and returns the EDID data for an attached monitor. Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--hw/Makefile.objs1
-rw-r--r--hw/i2c-ddc.c300
2 files changed, 301 insertions, 0 deletions
diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index e277cac79d..574793b2e5 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -137,6 +137,7 @@ common-obj-$(CONFIG_ADS7846) += ads7846.o
common-obj-$(CONFIG_MAX111X) += max111x.o
common-obj-$(CONFIG_DS1338) += ds1338.o
common-obj-y += i2c.o spi.o smbus.o smbus_eeprom.o
+common-obj-y += i2c-ddc.o
common-obj-y += eeprom93xx.o
common-obj-y += scsi-disk.o cdrom.o hd-geometry.o block-common.o
common-obj-y += scsi-generic.o scsi-bus.o
diff --git a/hw/i2c-ddc.c b/hw/i2c-ddc.c
new file mode 100644
index 0000000000..b7d7a52a12
--- /dev/null
+++ b/hw/i2c-ddc.c
@@ -0,0 +1,300 @@
+/* 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 "i2c.h"
+
+//#define DEBUG_I2CDDC
+#ifdef DEBUG_I2CDDC
+#define DPRINTF(fmt, ...) do { printf(fmt , ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) do {} while(0)
+#endif
+
+/* 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.
+ */
+typedef struct {
+ 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];
+} edid_data;
+
+/* EDID data for a simple LCD monitor */
+static const edid_data 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 edid_data *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 edid_data *edid, uint8_t *blob)
+{
+ /* Write an EDID 1.3 format blob (128 bytes) based
+ * on the edid_data 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;
+ DPRINTF("EDID blob:");
+ for (i = 0; i < 127; i++) {
+ cksum += blob[i];
+ DPRINTF("%c0x%02x,", i % 8 ? ' ' : '\n', blob[i]);
+ }
+ /* 127 : checksum */
+ blob[127] = -cksum;
+ DPRINTF(" 0x%02x\n", blob[127]);
+}
+
+
+
+/* A simple I2C slave which just returns the contents of its EDID blob. */
+
+typedef struct I2CDDCState_s {
+ I2CSlave i2c;
+ int firstbyte;
+ uint8_t reg;
+ uint8_t edid_blob[128];
+} I2CDDCState;
+
+static void i2c_ddc_reset(DeviceState *ds)
+{
+ I2CDDCState *s = FROM_I2C_SLAVE(I2CDDCState, I2C_SLAVE_FROM_QDEV(ds));
+ s->firstbyte = 0;
+ s->reg = 0;
+}
+
+static void i2c_ddc_event(I2CSlave *i2c, enum i2c_event event)
+{
+ I2CDDCState *s = FROM_I2C_SLAVE(I2CDDCState, i2c);
+ if (event == I2C_START_SEND) {
+ s->firstbyte = 1;
+ }
+}
+
+static int i2c_ddc_rx(I2CSlave *i2c)
+{
+ I2CDDCState *s = FROM_I2C_SLAVE(I2CDDCState, i2c);
+ int value;
+ if (s->reg < sizeof(s->edid_blob)) {
+ value = s->edid_blob[s->reg];
+ } else {
+ value = 0;
+ }
+ s->reg++;
+ return value;
+}
+
+static int i2c_ddc_tx(I2CSlave *i2c, uint8_t data)
+{
+ I2CDDCState *s = FROM_I2C_SLAVE(I2CDDCState, i2c);
+ if (s->firstbyte) {
+ s->reg = data;
+ s->firstbyte = 0;
+ return 1;
+ }
+
+ /* Ignore all writes */
+ s->reg++;
+ return 1;
+}
+
+static int i2c_ddc_init(I2CSlave *i2c)
+{
+ I2CDDCState *s = FROM_I2C_SLAVE(I2CDDCState, i2c);
+ build_edid_blob(&lcd_edid, s->edid_blob);
+ return 0;
+}
+
+static void i2c_ddc_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
+ k->init = i2c_ddc_init;
+ k->event = i2c_ddc_event;
+ k->recv = i2c_ddc_rx;
+ k->send = i2c_ddc_tx;
+ dc->reset = i2c_ddc_reset;
+ // XXX vmstate?
+}
+
+static TypeInfo i2c_ddc_info = {
+ .name = "i2c-ddc",
+ .parent = TYPE_I2C_SLAVE,
+ .instance_size = sizeof(I2CDDCState),
+ .class_init = i2c_ddc_class_init,
+};
+
+static void ddc_register_types(void)
+{
+ type_register_static(&i2c_ddc_info);
+}
+
+type_init(ddc_register_types);