OMAPDSS: HDMI: Add EDID read support for OMAP5

Core block in OMAP5 HDMI is different from OMAP4. so add support
to read EDID.

Signed-off-by: Mythri P K <mythripk@ti.com>

3 files changed, 110 insertions, 1 deletions

diff --git a/drivers/video/omap2/dss/dss_features.c b/drivers/video/omap2/dss/dss_features.c
index a697bf3d0522..e55223253740 100644
--- a/drivers/video/omap2/dss/dss_features.c
+++ b/drivers/video/omap2/dss/dss_features.c
@@ -704,7 +704,7 @@ static const struct ti_hdmi_ip_ops omap5_hdmi_functions = {
 	.video_configure	=	ti_hdmi_5xxx_basic_configure,
 	.phy_enable		=	ti_hdmi_4xxx_phy_enable,
 	.phy_disable		=	ti_hdmi_4xxx_phy_disable,
-	.read_edid		=	NULL,
+	.read_edid		=	ti_hdmi_5xxx_read_edid,
 	.pll_enable		=	ti_hdmi_4xxx_pll_enable,
 	.pll_disable		=	ti_hdmi_4xxx_pll_disable,
 	.video_enable		=	ti_hdmi_4xxx_wp_video_start,
diff --git a/drivers/video/omap2/dss/ti_hdmi.h b/drivers/video/omap2/dss/ti_hdmi.h
index b592af07c0fa..17a3b58f2615 100644
--- a/drivers/video/omap2/dss/ti_hdmi.h
+++ b/drivers/video/omap2/dss/ti_hdmi.h
@@ -203,4 +203,6 @@ int ti_hdmi_4xxx_audio_config(struct hdmi_ip_data *ip_data,
 #endif
 void ti_hdmi_5xxx_basic_configure(struct hdmi_ip_data *ip_data);
 void ti_hdmi_5xxx_core_dump(struct hdmi_ip_data *ip_data, struct seq_file *s);
+int ti_hdmi_5xxx_read_edid(struct hdmi_ip_data *ip_data,
+				u8 *edid, int len);
 #endif
diff --git a/drivers/video/omap2/dss/ti_hdmi_5xxx_ip.c b/drivers/video/omap2/dss/ti_hdmi_5xxx_ip.c
index f9b978eba841..8a56c938663c 100644
--- a/drivers/video/omap2/dss/ti_hdmi_5xxx_ip.c
+++ b/drivers/video/omap2/dss/ti_hdmi_5xxx_ip.c
@@ -61,6 +61,113 @@ static inline int hdmi_wait_for_bit_change(void __iomem *base_addr,
 	return val;
 }
 
+static inline void hdmi_core_ddc_req_addr(struct hdmi_ip_data *ip_data,
+						u8 addr, int ext)
+{
+	u8 seg_ptr = ext / 2;
+	u8 edidaddr = ((ext % 2) * 0x80) + addr;
+	void __iomem *core_sys_base = hdmi_core_sys_base(ip_data);
+
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_ADDRESS, edidaddr, 7, 0);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_SEGPTR, seg_ptr, 7, 0);
+
+	if (seg_ptr)
+		REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_OPERATION, 1, 1, 1);
+	else
+		REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_OPERATION, 1, 0, 0);
+}
+
+static void hdmi_core_ddc_init(struct hdmi_ip_data *ip_data)
+{
+	void __iomem *core_sys_base = hdmi_core_sys_base(ip_data);
+
+	/*Mask the interrupts*/
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_CTLINT, 0x0, 2, 2);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_CTLINT, 0x0, 6, 6);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_INT, 0x0, 2, 2);
+
+	/* Master clock division */
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_DIV, 0x5, 2, 0);
+
+	/* Standard speed counter */
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_SS_SCL_HCNT_1_ADDR, 0x0, 7, 0);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_SS_SCL_HCNT_0_ADDR, 0x79, 7, 0);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_SS_SCL_LCNT_1_ADDR, 0x0, 7, 0);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_SS_SCL_LCNT_0_ADDR, 0x91, 7, 0);
+
+	/* Fast speed counter*/
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_FS_SCL_HCNT_1_ADDR, 0x0, 7, 0);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_FS_SCL_HCNT_0_ADDR, 0x0F, 7, 0);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_FS_SCL_LCNT_1_ADDR, 0x0, 7, 0);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_FS_SCL_LCNT_0_ADDR, 0x21, 7, 0);
+
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_SLAVE, 0x50, 6, 0);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_SEGADDR, 0x30, 6, 0);
+}
+
+static int hdmi_core_ddc_edid(struct hdmi_ip_data *ip_data,
+					u8 *pedid, int ext)
+{
+	u8 cur_addr = 0;
+	char checksum = 0;
+	void __iomem *core_sys_base = hdmi_core_sys_base(ip_data);
+
+	hdmi_core_ddc_req_addr(ip_data, cur_addr, ext);
+
+	/* Unmask the interrupts*/
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_CTLINT, 0x1, 2, 2);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_CTLINT, 0x1, 6, 6);
+	REG_FLD_MOD(core_sys_base, HDMI_CORE_I2CM_INT, 0x1, 2, 2);
+
+	/* FIXME:This is a hack to  read only 128 bytes data with a mdelay
+	 * Ideally the read has to be based on the done interrupt and
+	 * status which is not received thus it is ignored for now
+	 */
+	while (cur_addr < 128) {
+	#if 0
+		if (hdmi_wait_for_bit_change(HDMI_CORE_I2CM_INT,
+						0, 0, 1) != 1) {
+			DSSERR("Failed to recieve done interrupt\n");
+			return -ETIMEDOUT;
+		}
+	#endif
+		mdelay(1);
+		pedid[cur_addr] = REG_GET(core_sys_base,
+					HDMI_CORE_I2CM_DATAI, 7, 0);
+		DSSDBG("pedid[%d] = %d", cur_addr, pedid[cur_addr]);
+		checksum += pedid[cur_addr++];
+		hdmi_core_ddc_req_addr(ip_data, cur_addr, ext);
+	}
+	return 0;
+
+}
+
+int ti_hdmi_5xxx_read_edid(struct hdmi_ip_data *ip_data,
+				u8 *edid, int len)
+{
+	int r, l;
+
+	if (len < 128)
+		return -EINVAL;
+
+	hdmi_core_ddc_init(ip_data);
+
+	r = hdmi_core_ddc_edid(ip_data, edid, 0);
+	if (r)
+		return r;
+
+	l = 128;
+
+	if (len >= 128 * 2 && edid[0x7e] > 0) {
+		r = hdmi_core_ddc_edid(ip_data, edid + 0x80, 1);
+		if (r)
+			return r;
+		l += 128;
+	}
+
+	return l;
+}
+
 void ti_hdmi_5xxx_core_dump(struct hdmi_ip_data *ip_data, struct seq_file *s)
 {