[coreboot-gerrit] New patch to review for coreboot: google/veyron*: Pulse the i2c clock once if sda was low

[Patrick Georgi (pgeorgi@google.com)]

Patrick Georgi (pgeorgi at google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/12451

-gerrit

commit 1f29fabf8191a51feb0640af365b400b4f9139c5
Author: Douglas Anderson <dianders at chromium.org>
Date:   Tue Oct 27 16:05:15 2015 -0700

    google/veyron*: Pulse the i2c clock once if sda was low
    
    On one particular TV the TV was holding SDA low when it came up.  It
    would release the SDA when the SCL went low the first time.
    Unfortunately the HDMI i2c port wouldn't transmit until the SDA was
    released.
    
    Let's detect this case and insert a bogus clock pulse to try to get the
    other side to release SDA.
    
    It's unclear why the kernel doesn't have this problem.
    
    BRANCH=none
    BUG=chrome-os-partner:46256
    TEST=Insignia TV works now
    
    Change-Id: Ic9d27eb69bdc9c5fb11a68258e0c755cdc8b79d7
    Signed-off-by: Patrick Georgi <pgeorgi at chromium.org>
    Original-Commit-Id: 356ee7503f04e741a41be37ad573b588067b7114
    Original-Change-Id: I4b6361877e0576cc4ea2f643f073f1aab660e434
    Original-Signed-off-by: Douglas Anderson <dianders at chromium.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/309258
    Original-Reviewed-by: Agnes Cheng <agnescheng at google.com>
    Original-Commit-Queue: Agnes Cheng <agnescheng at google.com>
    Original-Trybot-Ready: Agnes Cheng <agnescheng at google.com>
    Original-Tested-by: Agnes Cheng <agnescheng at google.com>
    Original-Reviewed-on: https://chromium-review.googlesource.com/309546
    Original-Commit-Ready: David Hendricks <dhendrix at chromium.org>
    Original-Tested-by: David Hendricks <dhendrix at chromium.org>
    Original-Reviewed-by: David Hendricks <dhendrix at chromium.org>
---
 src/mainboard/google/veyron_brain/mainboard.c  |  4 ----
 src/mainboard/google/veyron_danger/mainboard.c |  4 ----
 src/mainboard/google/veyron_mickey/mainboard.c |  4 ----
 src/soc/rockchip/rk3288/hdmi.c                 | 16 ++++++++++++++++
 4 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/src/mainboard/google/veyron_brain/mainboard.c b/src/mainboard/google/veyron_brain/mainboard.c
index 336879c..22faf64 100644
--- a/src/mainboard/google/veyron_brain/mainboard.c
+++ b/src/mainboard/google/veyron_brain/mainboard.c
@@ -82,10 +82,6 @@ static void configure_hdmi(void)
 
 	/* set POWER_HDMI_ON */
 	gpio_output(GPIO(7, A, 2), 1);
-
-	/* HDMI I2C */
-	write32(&rk3288_grf->iomux_i2c5sda, IOMUX_HDMI_EDP_I2C_SDA);
-	write32(&rk3288_grf->iomux_i2c5scl, IOMUX_HDMI_EDP_I2C_SCL);
 }
 
 static void mainboard_init(device_t dev)
diff --git a/src/mainboard/google/veyron_danger/mainboard.c b/src/mainboard/google/veyron_danger/mainboard.c
index 8288e4d..f923da9 100644
--- a/src/mainboard/google/veyron_danger/mainboard.c
+++ b/src/mainboard/google/veyron_danger/mainboard.c
@@ -137,10 +137,6 @@ static void configure_hdmi(void)
 		gpio_output(GPIO(5, C, 3), 1);
 		break;
 	}
-
-	/* HDMI I2C */
-	write32(&rk3288_grf->iomux_i2c5sda, IOMUX_HDMI_EDP_I2C_SDA);
-	write32(&rk3288_grf->iomux_i2c5scl, IOMUX_HDMI_EDP_I2C_SCL);
 }
 
 static void mainboard_init(device_t dev)
diff --git a/src/mainboard/google/veyron_mickey/mainboard.c b/src/mainboard/google/veyron_mickey/mainboard.c
index f07e5f2..27e9f74 100644
--- a/src/mainboard/google/veyron_mickey/mainboard.c
+++ b/src/mainboard/google/veyron_mickey/mainboard.c
@@ -75,10 +75,6 @@ static void configure_vop(void)
 
 static void configure_hdmi(void)
 {
-	/* HDMI I2C */
-	write32(&rk3288_grf->iomux_i2c5sda, IOMUX_HDMI_EDP_I2C_SDA);
-	write32(&rk3288_grf->iomux_i2c5scl, IOMUX_HDMI_EDP_I2C_SCL);
-
 	gpio_output(GPIO(7, B, 3), 1);	/* POWER_HDMI_ON */
 }
 
diff --git a/src/soc/rockchip/rk3288/hdmi.c b/src/soc/rockchip/rk3288/hdmi.c
index 805b98a..1a825ab 100644
--- a/src/soc/rockchip/rk3288/hdmi.c
+++ b/src/soc/rockchip/rk3288/hdmi.c
@@ -15,6 +15,7 @@
 #include <console/console.h>
 #include <delay.h>
 #include <edid.h>
+#include <gpio.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
@@ -774,8 +775,23 @@ int rk_hdmi_get_edid(struct edid *edid)
 {
 	u8 edid_buf[HDMI_EDID_BLOCK_SIZE * 2];
 	u32 edid_size = HDMI_EDID_BLOCK_SIZE;
+	gpio_t hdmi_i2c_sda = GPIO(7, C, 3);
+	gpio_t hdmi_i2c_scl = GPIO(7, C, 4);
 	int ret;
 
+	/* If SDA is low, try to clock once to fix it */
+	gpio_input_pullup(hdmi_i2c_sda);
+	if (gpio_get(hdmi_i2c_sda) == 0) {
+		gpio_output(hdmi_i2c_scl, 0);
+		udelay(1000);
+		gpio_input_pullup(hdmi_i2c_scl);
+		udelay(1000);
+	}
+
+	/* HDMI I2C */
+	write32(&rk3288_grf->iomux_i2c5sda, IOMUX_HDMI_EDP_I2C_SDA);
+	write32(&rk3288_grf->iomux_i2c5scl, IOMUX_HDMI_EDP_I2C_SCL);
+
 	ret = hdmi_read_edid(0, edid_buf);
 	if (ret) {
 		hdmi_debug("failed to read edid.\n");