msm: mdss: Serve HDMI Tx power off in a separate context

HDMI Tx core should not be powered down until the audio engine has
shutdown transmitting packets to the HDMI Tx core. This change moves
the power off sequence to a separate thread so that framebuffer
close system call does not get blocked.

Change-Id: I011c6612ec1b6be047e4adb39c1af48f6a105bed
Signed-off-by: Ujwal Patel <ujwalp@codeaurora.org>

2 files changed, 68 insertions, 20 deletions

diff --git a/drivers/video/fbdev/msm/mdss_hdmi_tx.c b/drivers/video/fbdev/msm/mdss_hdmi_tx.c
index ff8a6910c573..43d56522350e 100644
--- a/drivers/video/fbdev/msm/mdss_hdmi_tx.c
+++ b/drivers/video/fbdev/msm/mdss_hdmi_tx.c
@@ -15,6 +15,7 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/iopoll.h>
 #include <linux/of_address.h>
 #include <linux/of_gpio.h>
 #include <linux/types.h>
@@ -1475,7 +1476,8 @@ static int hdmi_tx_audio_info_setup(void *priv_d, bool enabled,
 	}
 	DSS_REG_W(io, HDMI_INFOFRAME_CTRL0, audio_info_ctrl_reg);
 
-	dss_reg_dump(io->base, io->len, "HDMI-AUDIO-ON: ", REG_DUMP);
+	dss_reg_dump(io->base, io->len,
+		enabled ? "HDMI-AUDIO-ON: " : "HDMI-AUDIO-OFF: ", REG_DUMP);
 
 	return 0;
 } /* hdmi_tx_audio_info_setup */
@@ -1518,8 +1520,7 @@ static int hdmi_tx_audio_setup(struct hdmi_tx_ctrl *hdmi_ctrl)
 
 static void hdmi_tx_audio_off(struct hdmi_tx_ctrl *hdmi_ctrl)
 {
-	int i;
-	u32 audio_pkt_ctrl, audio_cfg;
+	u32 i, status, max_reads, timeout_us, timeout_sec = 15;
 	struct dss_io_data *io = NULL;
 
 	if (!hdmi_ctrl) {
@@ -1533,15 +1534,26 @@ static void hdmi_tx_audio_off(struct hdmi_tx_ctrl *hdmi_ctrl)
 		return;
 	}
 
-	/* Number of wait iterations */
-	i = 10;
-	do {
-		audio_pkt_ctrl = DSS_REG_R_ND(io, HDMI_AUDIO_PKT_CTRL);
-		audio_cfg = DSS_REG_R_ND(io, HDMI_AUDIO_CFG);
-		DEV_DBG("%s: i=%d, AUDIO PACKET=%08x, AUDIO CFG=%08x",
-			__func__, i, audio_pkt_ctrl, audio_cfg);
-		msleep(20);
-	} while (((audio_pkt_ctrl & BIT(0)) || (audio_cfg & BIT(0))) && i--);
+	/* Check if audio engine is turned off by QDSP or not */
+	/* send off notification after every 1 sec for 15 seconds */
+	for (i = 0; i < timeout_sec; i++) {
+		max_reads = 500;
+		timeout_us = 1000 * 2;
+
+		if (readl_poll_timeout_noirq((io->base + HDMI_AUDIO_CFG),
+			status, ((status & BIT(0)) == 0),
+			max_reads, timeout_us)) {
+
+			DEV_ERR("%s: audio still on after %d sec. try again\n",
+				__func__, i+1);
+
+			switch_set_state(&hdmi_ctrl->audio_sdev, 0);
+			continue;
+		}
+		break;
+	}
+	if (i == timeout_sec)
+		DEV_ERR("%s: Error: cannot turn off audio engine\n", __func__);
 
 	if (hdmi_tx_audio_info_setup(hdmi_ctrl, false, 0, 0, 0, false))
 		DEV_ERR("%s: hdmi_tx_audio_info_setup failed.\n", __func__);
@@ -1629,17 +1641,22 @@ static void hdmi_tx_hpd_polarity_setup(struct hdmi_tx_ctrl *hdmi_ctrl,
 	}
 } /* hdmi_tx_hpd_polarity_setup */
 
-static int hdmi_tx_power_off(struct mdss_panel_data *panel_data)
+static void hdmi_tx_power_off_work(struct work_struct *work)
 {
-	struct hdmi_tx_ctrl *hdmi_ctrl =
-		hdmi_tx_get_drvdata_from_panel_data(panel_data);
+	struct hdmi_tx_ctrl *hdmi_ctrl = NULL;
+	struct dss_io_data *io = NULL;
 
-	if (!hdmi_ctrl || !hdmi_ctrl->panel_power_on) {
-		DEV_ERR("%s: invalid input\n", __func__);
-		return -EINVAL;
+	hdmi_ctrl = container_of(work, struct hdmi_tx_ctrl, power_off_work);
+	if (!hdmi_ctrl) {
+		DEV_DBG("%s: invalid input\n", __func__);
+		return;
 	}
 
-	DEV_INFO("%s: HDMI Core: OFF\n", __func__);
+	io = &hdmi_ctrl->pdata.io[HDMI_TX_CORE_IO];
+	if (!io->base) {
+		DEV_ERR("%s: Core io is not initialized\n", __func__);
+		return;
+	}
 
 	if (!hdmi_tx_is_dvi_mode(hdmi_ctrl)) {
 		switch_set_state(&hdmi_ctrl->audio_sdev, 0);
@@ -1650,11 +1667,35 @@ static int hdmi_tx_power_off(struct mdss_panel_data *panel_data)
 	}
 
 	hdmi_tx_powerdown_phy(hdmi_ctrl);
-	hdmi_ctrl->panel_power_on = false;
 	hdmi_tx_core_off(hdmi_ctrl);
 
+	mutex_lock(&hdmi_ctrl->mutex);
+	hdmi_ctrl->panel_power_on = false;
+	mutex_unlock(&hdmi_ctrl->mutex);
+
 	hdmi_tx_hpd_polarity_setup(hdmi_ctrl, HPD_CONNECT_POLARITY);
 
+	DEV_INFO("%s: HDMI Core: OFF\n", __func__);
+} /* hdmi_tx_power_off_work */
+
+static int hdmi_tx_power_off(struct mdss_panel_data *panel_data)
+{
+	struct hdmi_tx_ctrl *hdmi_ctrl =
+		hdmi_tx_get_drvdata_from_panel_data(panel_data);
+
+	if (!hdmi_ctrl || !hdmi_ctrl->panel_power_on) {
+		DEV_ERR("%s: invalid input\n", __func__);
+		return -EINVAL;
+	}
+
+	/*
+	 * Queue work item to handle power down sequence.
+	 * This is needed since we need to wait for the audio engine
+	 * to shutdown first before we shutdown the HDMI core.
+	 */
+	DEV_DBG("%s: Queuing work to power off HDMI core\n", __func__);
+	queue_work(hdmi_ctrl->workq, &hdmi_ctrl->power_off_work);
+
 	return 0;
 } /* hdmi_tx_power_off */
 
@@ -1681,6 +1722,9 @@ static int hdmi_tx_power_on(struct mdss_panel_data *panel_data)
 		return -EPERM;
 	}
 
+	/* If a power down is already underway, wait for it to finish */
+	flush_work(&hdmi_ctrl->power_off_work);
+
 	DEV_INFO("power: ON (%dx%d %ld)\n", hdmi_ctrl->xres, hdmi_ctrl->yres,
 		hdmi_ctrl->pixel_clk);
 
@@ -1912,6 +1956,8 @@ static int hdmi_tx_dev_init(struct hdmi_tx_ctrl *hdmi_ctrl)
 	hdmi_ctrl->hpd_state = false;
 	INIT_WORK(&hdmi_ctrl->hpd_int_work, hdmi_tx_hpd_int_work);
 
+	INIT_WORK(&hdmi_ctrl->power_off_work, hdmi_tx_power_off_work);
+
 	hdmi_ctrl->audio_sample_rate = HDMI_SAMPLE_RATE_48KHZ;
 
 	hdmi_ctrl->sdev.name = "hdmi";
diff --git a/drivers/video/fbdev/msm/mdss_hdmi_tx.h b/drivers/video/fbdev/msm/mdss_hdmi_tx.h
index cec3394350f3..641b6ce0c410 100644
--- a/drivers/video/fbdev/msm/mdss_hdmi_tx.h
+++ b/drivers/video/fbdev/msm/mdss_hdmi_tx.h
@@ -57,6 +57,8 @@ struct hdmi_tx_ctrl {
 	u32 hpd_feature_on;
 	struct work_struct hpd_int_work;
 
+	struct work_struct power_off_work;
+
 	unsigned long pixel_clk;
 	u32 xres;
 	u32 yres;