media: adv7842: support 1 block EDIDs, fix clearing EDID

Add support for EDIDs consisting of one EDID block.

Related to this, improve CEC physical address handling.

Clearing the EDID caused a bug since v4l2_calc_aspect_ratio() was
called with a NULL pointer.

Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/i2c/adv7842.c

···
 	v4l2_std_id norm;
 	struct {
 		u8 edid[256];
+		u32 blocks;
 		u32 present;
 	} hdmi_edid;
 	struct {
 		u8 edid[256];
+		u32 blocks;
 		u32 present;
 	} vga_edid;
 	struct v4l2_fract aspect_ratio;
···
 {
 	struct i2c_client *client = v4l2_get_subdevdata(sd);
 	struct adv7842_state *state = to_state(sd);
-	const u8 *val = state->vga_edid.edid;
+	const u8 *edid = state->vga_edid.edid;
+	u32 blocks = state->vga_edid.blocks;
 	int err = 0;
 	int i;
 
···
 	/* edid segment pointer '1' for VGA port */
 	rep_write_and_or(sd, 0x77, 0xef, 0x10);
 
-	for (i = 0; !err && i < 256; i += I2C_SMBUS_BLOCK_MAX)
+	for (i = 0; !err && i < blocks * 128; i += I2C_SMBUS_BLOCK_MAX)
 		err = i2c_smbus_write_i2c_block_data(state->i2c_edid, i,
 						     I2C_SMBUS_BLOCK_MAX,
-						     val + i);
+						     edid + i);
 	if (err)
 		return err;
 
···
 	struct i2c_client *client = v4l2_get_subdevdata(sd);
 	struct adv7842_state *state = to_state(sd);
 	const u8 *edid = state->hdmi_edid.edid;
+	u32 blocks = state->hdmi_edid.blocks;
 	int spa_loc;
-	u16 pa;
+	u16 pa, parent_pa;
 	int err = 0;
 	int i;
 
···
 		return 0;
 	}
 
-	pa = v4l2_get_edid_phys_addr(edid, 256, &spa_loc);
-	err = v4l2_phys_addr_validate(pa, &pa, NULL);
+	pa = v4l2_get_edid_phys_addr(edid, blocks * 128, &spa_loc);
+	err = v4l2_phys_addr_validate(pa, &parent_pa, NULL);
 	if (err)
 		return err;
 
-	/*
-	 * Return an error if no location of the source physical address
-	 * was found.
-	 */
-	if (spa_loc == 0)
-		return -EINVAL;
+	if (!spa_loc) {
+		/*
+		 * There is no SPA, so just set spa_loc to 128 and pa to whatever
+		 * data is there.
+		 */
+		spa_loc = 128;
+		pa = (edid[spa_loc] << 8) | edid[spa_loc + 1];
+	}
 
 	/* edid segment pointer '0' for HDMI ports */
 	rep_write_and_or(sd, 0x77, 0xef, 0x00);
 
-	for (i = 0; !err && i < 256; i += I2C_SMBUS_BLOCK_MAX)
+	for (i = 0; !err && i < blocks * 128; i += I2C_SMBUS_BLOCK_MAX)
 		err = i2c_smbus_write_i2c_block_data(state->i2c_edid, i,
 						     I2C_SMBUS_BLOCK_MAX, edid + i);
 	if (err)
 		return err;
 
 	if (port == ADV7842_EDID_PORT_A) {
-		rep_write(sd, 0x72, edid[spa_loc]);
-		rep_write(sd, 0x73, edid[spa_loc + 1]);
+		rep_write(sd, 0x72, pa >> 8);
+		rep_write(sd, 0x73, pa & 0xff);
 	} else {
-		rep_write(sd, 0x74, edid[spa_loc]);
-		rep_write(sd, 0x75, edid[spa_loc + 1]);
+		rep_write(sd, 0x74, pa >> 8);
+		rep_write(sd, 0x75, pa & 0xff);
 	}
 	rep_write(sd, 0x76, spa_loc & 0xff);
 	rep_write_and_or(sd, 0x77, 0xbf, (spa_loc >> 2) & 0x40);
···
 				(port == ADV7842_EDID_PORT_A) ? 'A' : 'B');
 		return -EIO;
 	}
-	cec_s_phys_addr(state->cec_adap, pa, false);
+	cec_s_phys_addr(state->cec_adap, parent_pa, false);
 
 	/* enable hotplug after 200 ms */
 	schedule_delayed_work(&state->delayed_work_enable_hotplug, HZ / 5);
···
 static int adv7842_get_edid(struct v4l2_subdev *sd, struct v4l2_edid *edid)
 {
 	struct adv7842_state *state = to_state(sd);
+	u32 blocks = 0;
 	u8 *data = NULL;
 
 	memset(edid->reserved, 0, sizeof(edid->reserved));
···
 	switch (edid->pad) {
 	case ADV7842_EDID_PORT_A:
 	case ADV7842_EDID_PORT_B:
-		if (state->hdmi_edid.present & (0x04 << edid->pad))
+		if (state->hdmi_edid.present & (0x04 << edid->pad)) {
 			data = state->hdmi_edid.edid;
+			blocks = state->hdmi_edid.blocks;
+		}
 		break;
 	case ADV7842_EDID_PORT_VGA:
-		if (state->vga_edid.present)
+		if (state->vga_edid.present) {
 			data = state->vga_edid.edid;
+			blocks = state->vga_edid.blocks;
+		}
 		break;
 	default:
 		return -EINVAL;
 	}
 
 	if (edid->start_block == 0 && edid->blocks == 0) {
-		edid->blocks = data ? 2 : 0;
+		edid->blocks = blocks;
 		return 0;
 	}
 
 	if (!data)
 		return -ENODATA;
 
-	if (edid->start_block >= 2)
+	if (edid->start_block >= blocks)
 		return -EINVAL;
 
-	if (edid->start_block + edid->blocks > 2)
-		edid->blocks = 2 - edid->start_block;
+	if (edid->start_block + edid->blocks > blocks)
+		edid->blocks = blocks - edid->start_block;
 
 	memcpy(edid->edid, data + edid->start_block * 128, edid->blocks * 128);
 
···
 	}
 
 	/* todo, per edid */
-	state->aspect_ratio = v4l2_calc_aspect_ratio(e->edid[0x15],
-			e->edid[0x16]);
+	if (e->blocks)
+		state->aspect_ratio = v4l2_calc_aspect_ratio(e->edid[0x15],
+							     e->edid[0x16]);
 
 	switch (e->pad) {
 	case ADV7842_EDID_PORT_VGA:
 		memset(&state->vga_edid.edid, 0, 256);
+		state->vga_edid.blocks = e->blocks;
 		state->vga_edid.present = e->blocks ? 0x1 : 0x0;
-		memcpy(&state->vga_edid.edid, e->edid, 128 * e->blocks);
+		if (e->blocks)
+			memcpy(&state->vga_edid.edid, e->edid, 128 * e->blocks);
 		err = edid_write_vga_segment(sd);
 		break;
 	case ADV7842_EDID_PORT_A:
 	case ADV7842_EDID_PORT_B:
 		memset(&state->hdmi_edid.edid, 0, 256);
+		state->hdmi_edid.blocks = e->blocks;
 		if (e->blocks) {
 			state->hdmi_edid.present |= 0x04 << e->pad;
+			memcpy(&state->hdmi_edid.edid, e->edid, 128 * e->blocks);
 		} else {
 			state->hdmi_edid.present &= ~(0x04 << e->pad);
 			adv7842_s_detect_tx_5v_ctrl(sd);
 		}
-		memcpy(&state->hdmi_edid.edid, e->edid, 128 * e->blocks);
 		err = edid_write_hdmi_segment(sd, e->pad);
 		break;
 	default: