+static int sunxi_hdmi_ddc_do_command(u32 cmnd, int offset, int n)
+{
+ struct sunxi_hdmi_reg * const hdmi =
+ (struct sunxi_hdmi_reg *)SUNXI_HDMI_BASE;
+
+ setbits_le32(&hdmi->ddc_fifo_ctrl, SUNXI_HDMI_DDC_FIFO_CTRL_CLEAR);
+ writel(SUNXI_HMDI_DDC_ADDR_EDDC_SEGMENT(offset >> 8) |
+ SUNXI_HMDI_DDC_ADDR_EDDC_ADDR |
+ SUNXI_HMDI_DDC_ADDR_OFFSET(offset) |
+ SUNXI_HMDI_DDC_ADDR_SLAVE_ADDR, &hdmi->ddc_addr);
+#ifndef CONFIG_MACH_SUN6I
+ writel(n, &hdmi->ddc_byte_count);
+ writel(cmnd, &hdmi->ddc_cmnd);
+#else
+ writel(n << 16 | cmnd, &hdmi->ddc_cmnd);
+#endif
+ setbits_le32(&hdmi->ddc_ctrl, SUNXI_HMDI_DDC_CTRL_START);
+
+ return await_completion(&hdmi->ddc_ctrl, SUNXI_HMDI_DDC_CTRL_START, 0);
+}
+
+static int sunxi_hdmi_ddc_read(int offset, u8 *buf, int count)
+{
+ struct sunxi_hdmi_reg * const hdmi =
+ (struct sunxi_hdmi_reg *)SUNXI_HDMI_BASE;
+ int i, n;
+
+ while (count > 0) {
+ if (count > 16)
+ n = 16;
+ else
+ n = count;
+
+ if (sunxi_hdmi_ddc_do_command(
+ SUNXI_HDMI_DDC_CMND_EXPLICIT_EDDC_READ,
+ offset, n))
+ return -ETIME;
+
+ for (i = 0; i < n; i++)
+ *buf++ = readb(&hdmi->ddc_fifo_data);
+
+ offset += n;
+ count -= n;
+ }
+
+ return 0;
+}
+
+static int sunxi_hdmi_edid_get_mode(struct ctfb_res_modes *mode)
+{
+ struct edid1_info edid1;
+ struct edid_detailed_timing *t =
+ (struct edid_detailed_timing *)edid1.monitor_details.timing;
+ struct sunxi_hdmi_reg * const hdmi =
+ (struct sunxi_hdmi_reg *)SUNXI_HDMI_BASE;
+ struct sunxi_ccm_reg * const ccm =
+ (struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+ int i, r, retries = 2;
+
+ /* SUNXI_HDMI_CTRL_ENABLE & PAD_CTRL0 are already set by hpd_detect */
+ writel(SUNXI_HDMI_PAD_CTRL1 | SUNXI_HDMI_PAD_CTRL1_HALVE,
+ &hdmi->pad_ctrl1);
+ writel(SUNXI_HDMI_PLL_CTRL | SUNXI_HDMI_PLL_CTRL_DIV(15),
+ &hdmi->pll_ctrl);
+ writel(SUNXI_HDMI_PLL_DBG0_PLL3, &hdmi->pll_dbg0);
+
+ /* Reset i2c controller */
+ setbits_le32(&ccm->hdmi_clk_cfg, CCM_HDMI_CTRL_DDC_GATE);
+ writel(SUNXI_HMDI_DDC_CTRL_ENABLE |
+ SUNXI_HMDI_DDC_CTRL_SDA_ENABLE |
+ SUNXI_HMDI_DDC_CTRL_SCL_ENABLE |
+ SUNXI_HMDI_DDC_CTRL_RESET, &hdmi->ddc_ctrl);
+ if (await_completion(&hdmi->ddc_ctrl, SUNXI_HMDI_DDC_CTRL_RESET, 0))
+ return -EIO;
+
+ writel(SUNXI_HDMI_DDC_CLOCK, &hdmi->ddc_clock);
+#ifndef CONFIG_MACH_SUN6I
+ writel(SUNXI_HMDI_DDC_LINE_CTRL_SDA_ENABLE |
+ SUNXI_HMDI_DDC_LINE_CTRL_SCL_ENABLE, &hdmi->ddc_line_ctrl);
+#endif
+
+ do {
+ r = sunxi_hdmi_ddc_read(0, (u8 *)&edid1, 128);
+ if (r)
+ continue;
+ r = edid_check_checksum((u8 *)&edid1);
+ if (r) {
+ printf("EDID: checksum error%s\n",
+ retries ? ", retrying" : "");
+ }
+ } while (r && retries--);
+
+ /* Disable DDC engine, no longer needed */
+ clrbits_le32(&hdmi->ddc_ctrl, SUNXI_HMDI_DDC_CTRL_ENABLE);
+ clrbits_le32(&ccm->hdmi_clk_cfg, CCM_HDMI_CTRL_DDC_GATE);
+
+ if (r)
+ return r;
+
+ r = edid_check_info(&edid1);
+ if (r) {
+ printf("EDID: invalid EDID data\n");
+ return -EINVAL;
+ }
+
+ /* We want version 1.3 or 1.2 with detailed timing info */
+ if (edid1.version != 1 || (edid1.revision < 3 &&
+ !EDID1_INFO_FEATURE_PREFERRED_TIMING_MODE(edid1))) {
+ printf("EDID: unsupported version %d.%d\n",
+ edid1.version, edid1.revision);
+ return -EINVAL;
+ }
+
+ /* Take the first usable detailed timing */
+ for (i = 0; i < 4; i++, t++) {
+ r = video_edid_dtd_to_ctfb_res_modes(t, mode);
+ if (r == 0)
+ break;
+ }
+ if (i == 4) {
+ printf("EDID: no usable detailed timing found\n");
+ return -ENOENT;
+ }
+
+ return 0;
+}
+