OMAPDSS: HDMI: Disable DDC internal pull up

Disables the internal pull resistor for SDA and SCL which are enabled by
default, as there are external pull up's in 4460 and 4430 ES2.3
SDP, Blaze and Panda Boards, It is done to avoid the EDID read failure.

Signed-off-by: Ricardo Salveti de Araujo <ricardo.salveti@linaro.org>
Signed-off-by: Mythri P K <mythripk@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 19 insertions, 3 deletions

diff --git a/arch/arm/mach-omap2/display.c b/arch/arm/mach-omap2/display.c
index 8436088ffe13..ffd9bd983023 100644
--- a/arch/arm/mach-omap2/display.c
+++ b/arch/arm/mach-omap2/display.c
@@ -97,8 +97,11 @@ static const struct omap_dss_hwmod_data omap4_dss_hwmod_data[] __initdata = {
         { "dss_hdmi", "omapdss_hdmi", -1 },
 };
 
-static void omap4_hdmi_mux_pads()
+static void omap4_hdmi_mux_pads(enum omap_hdmi_flags flags)
 {
+        u32 reg;
+        u16 control_i2c_1;
+
         /* PAD0_HDMI_HPD_PAD1_HDMI_CEC */
         omap_mux_init_signal("hdmi_hpd",
                         OMAP_PIN_INPUT_PULLUP);
@@ -109,6 +112,19 @@ static void omap4_hdmi_mux_pads()
                         OMAP_PIN_INPUT_PULLUP);
         omap_mux_init_signal("hdmi_ddc_sda",
                         OMAP_PIN_INPUT_PULLUP);
+
+        /*
+         * CONTROL_I2C_1: HDMI_DDC_SDA_PULLUPRESX (bit 28) and
+         * HDMI_DDC_SCL_PULLUPRESX (bit 24) are set to disable
+         * internal pull up resistor.
+         */
+        if (flags & OMAP_HDMI_SDA_SCL_EXTERNAL_PULLUP) {
+                control_i2c_1 = OMAP4_CTRL_MODULE_PAD_CORE_CONTROL_I2C_1;
+                reg = omap4_ctrl_pad_readl(control_i2c_1);
+                reg |= (OMAP4_HDMI_DDC_SDA_PULLUPRESX_MASK |
+                        OMAP4_HDMI_DDC_SCL_PULLUPRESX_MASK);
+                        omap4_ctrl_pad_writel(reg, control_i2c_1);
+        }
 }
 
 static int omap4_dsi_mux_pads(int dsi_id, unsigned lanes)
@@ -144,10 +160,10 @@ static int omap4_dsi_mux_pads(int dsi_id, unsigned lanes)
         return 0;
 }
 
-int omap_hdmi_init(void)
+int omap_hdmi_init(enum omap_hdmi_flags flags)
 {
         if (cpu_is_omap44xx())
-                omap4_hdmi_mux_pads();
+                omap4_hdmi_mux_pads(flags);
 
         return 0;
 }