msm: mdss: Check DSI controller status periodically

Send Bus-Turn-Around (BTA) command to check DSI controller
status periodically and check the response from controller.
Update appropriate response in frame buffer status node
if controller is not responding.

Sending BTA command is useful for the video/command mode
panels when it stops responding during ESD stability tests.

Change-Id: Ic8710943c0d56ea013af9ee6d378dabdda75d8f0
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>
[cip@codeaurora.org: Moved mdss_dsi_status.c file location]
Signed-off-by: Clarence Ip <cip@codeaurora.org>

3 files changed, 218 insertions, 0 deletions

diff --git a/drivers/video/fbdev/msm/Kconfig b/drivers/video/fbdev/msm/Kconfig
index 73be6f060926..cad2365ae508 100644
--- a/drivers/video/fbdev/msm/Kconfig
+++ b/drivers/video/fbdev/msm/Kconfig
@@ -979,4 +979,12 @@ config FB_MSM_MDSS_HDMI_MHL_SII8334
 	  MHL (Mobile High-Definition Link) technology
 	  uses USB connector to output HDMI content
 
+config FB_MSM_MDSS_DSI_CTRL_STATUS
+	tristate "DSI controller status check feature"
+	---help---
+	  Check DSI controller status periodically (default period is 5
+	  seconds) by sending Bus-Turn-Around (BTA) command. If DSI controller
+	  fails to acknowledge the BTA command, it sends PANEL_ALIVE=0 status
+	  to HAL layer to reset the controller.
+
 endif
diff --git a/drivers/video/fbdev/msm/Makefile b/drivers/video/fbdev/msm/Makefile
index b62808580848..163090425d73 100644
--- a/drivers/video/fbdev/msm/Makefile
+++ b/drivers/video/fbdev/msm/Makefile
@@ -43,3 +43,5 @@ obj-$(CONFIG_FB_MSM_QPIC) += mdss-qpic.o
 obj-$(CONFIG_FB_MSM_QPIC_ILI_QVGA_PANEL) += qpic_panel_ili_qvga.o
 
 obj-$(CONFIG_FB_MSM_MDSS) += mdss_fb.o
+
+obj-$(CONFIG_FB_MSM_MDSS_DSI_CTRL_STATUS) += mdss_dsi_status.o
diff --git a/drivers/video/fbdev/msm/mdss_dsi_status.c b/drivers/video/fbdev/msm/mdss_dsi_status.c
new file mode 100644
index 000000000000..f0c4f4c2b72f
--- /dev/null
+++ b/drivers/video/fbdev/msm/mdss_dsi_status.c
@@ -0,0 +1,208 @@
+/* Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/fb.h>
+#include <linux/notifier.h>
+#include <linux/workqueue.h>
+#include <linux/delay.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/iopoll.h>
+#include <linux/kobject.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+
+#include "mdss_fb.h"
+#include "mdss_dsi.h"
+#include "mdss_panel.h"
+#include "mdss_mdp.h"
+
+#define STATUS_CHECK_INTERVAL 5000
+
+struct dsi_status_data {
+	struct notifier_block fb_notifier;
+	struct delayed_work check_status;
+	struct msm_fb_data_type *mfd;
+	uint32_t check_interval;
+};
+struct dsi_status_data *pstatus_data;
+static uint32_t interval = STATUS_CHECK_INTERVAL;
+
+/*
+ * check_dsi_ctrl_status() - Check DSI controller status periodically.
+ * @work  : dsi controller status data
+ *
+ * This function calls check_status API on DSI controller to send the BTA
+ * command. If DSI controller fails to acknowledge the BTA command, it sends
+ * the PANEL_ALIVE=0 status to HAL layer.
+ */
+static void check_dsi_ctrl_status(struct work_struct *work)
+{
+	struct dsi_status_data *pdsi_status = NULL;
+	struct mdss_panel_data *pdata = NULL;
+	struct mdss_dsi_ctrl_pdata *ctrl_pdata = NULL;
+	struct mdss_overlay_private *mdp5_data = NULL;
+	struct mdss_mdp_ctl *ctl = NULL;
+	int ret = 0;
+
+	pdsi_status = container_of(to_delayed_work(work),
+		struct dsi_status_data, check_status);
+	if (!pdsi_status) {
+		pr_err("%s: DSI status data not available\n", __func__);
+		return;
+	}
+
+	pdata = dev_get_platdata(&pdsi_status->mfd->pdev->dev);
+	if (!pdata) {
+		pr_err("%s: Panel data not available\n", __func__);
+		return;
+	}
+
+	ctrl_pdata = container_of(pdata, struct mdss_dsi_ctrl_pdata,
+							panel_data);
+	if (!ctrl_pdata || !ctrl_pdata->check_status) {
+		pr_err("%s: DSI ctrl or status_check callback not available\n",
+								__func__);
+		return;
+	}
+
+	mdp5_data = mfd_to_mdp5_data(pdsi_status->mfd);
+	ctl = mfd_to_ctl(pdsi_status->mfd);
+
+	if (ctl->shared_lock)
+		mutex_lock(ctl->shared_lock);
+	mutex_lock(&mdp5_data->ov_lock);
+
+	/*
+	 * For the command mode panels, we return pan display
+	 * IOCTL on vsync interrupt. So, after vsync interrupt comes
+	 * and when DMA_P is in progress, if the panel stops responding
+	 * and if we trigger BTA before DMA_P finishes, then the DSI
+	 * FIFO will not be cleared since the DSI data bus control
+	 * doesn't come back to the host after BTA. This may cause the
+	 * display reset not to be proper. Hence, wait for DMA_P done
+	 * for command mode panels before triggering BTA.
+	 */
+	if (ctl->wait_pingpong)
+		ctl->wait_pingpong(ctl, NULL);
+
+	pr_debug("%s: DSI ctrl wait for ping pong done\n", __func__);
+
+	mdss_mdp_clk_ctrl(MDP_BLOCK_POWER_ON, false);
+	ret = ctrl_pdata->check_status(ctrl_pdata);
+	mdss_mdp_clk_ctrl(MDP_BLOCK_POWER_OFF, false);
+
+	mutex_unlock(&mdp5_data->ov_lock);
+	if (ctl->shared_lock)
+		mutex_unlock(ctl->shared_lock);
+
+	if ((pdsi_status->mfd->panel_power_on)) {
+		if (ret > 0) {
+			schedule_delayed_work(&pdsi_status->check_status,
+				msecs_to_jiffies(pdsi_status->check_interval));
+		} else {
+			char *envp[2] = {"PANEL_ALIVE=0", NULL};
+			pdata->panel_info.panel_dead = true;
+			ret = kobject_uevent_env(
+				&pdsi_status->mfd->fbi->dev->kobj,
+							KOBJ_CHANGE, envp);
+			pr_err("%s: Panel has gone bad, sending uevent - %s\n",
+							__func__, envp[0]);
+		}
+	}
+}
+
+/*
+ * fb_event_callback() - Call back function for the fb_register_client()
+ *			 notifying events
+ * @self  : notifier block
+ * @event : The event that was triggered
+ * @data  : Of type struct fb_event
+ *
+ * This function listens for FB_BLANK_UNBLANK and FB_BLANK_POWERDOWN events
+ * from frame buffer. DSI status check work is either scheduled again after
+ * PANEL_STATUS_CHECK_INTERVAL or cancelled based on the event.
+ */
+static int fb_event_callback(struct notifier_block *self,
+				unsigned long event, void *data)
+{
+	struct fb_event *evdata = data;
+	struct dsi_status_data *pdata = container_of(self,
+				struct dsi_status_data, fb_notifier);
+	pdata->mfd = evdata->info->par;
+
+	if (event == FB_EVENT_BLANK && evdata) {
+		int *blank = evdata->data;
+		switch (*blank) {
+		case FB_BLANK_UNBLANK:
+			schedule_delayed_work(&pdata->check_status,
+				msecs_to_jiffies(pdata->check_interval));
+			break;
+		case FB_BLANK_POWERDOWN:
+			cancel_delayed_work(&pdata->check_status);
+			break;
+		}
+	}
+	return 0;
+}
+
+int __init mdss_dsi_status_init(void)
+{
+	int rc = 0;
+
+	pstatus_data = kzalloc(sizeof(struct dsi_status_data), GFP_KERNEL);
+	if (!pstatus_data) {
+		pr_err("%s: can't allocate memory\n", __func__);
+		return -ENOMEM;
+	}
+
+	pstatus_data->fb_notifier.notifier_call = fb_event_callback;
+
+	rc = fb_register_client(&pstatus_data->fb_notifier);
+	if (rc < 0) {
+		pr_err("%s: fb_register_client failed, returned with rc=%d\n",
+								__func__, rc);
+		kfree(pstatus_data);
+		return -EPERM;
+	}
+
+	pstatus_data->check_interval = interval;
+	pr_info("%s: DSI status check interval:%d\n", __func__,	interval);
+
+	INIT_DELAYED_WORK(&pstatus_data->check_status, check_dsi_ctrl_status);
+
+	pr_debug("%s: DSI ctrl status work queue initialized\n", __func__);
+
+	return rc;
+}
+
+void __exit mdss_dsi_status_exit(void)
+{
+	fb_unregister_client(&pstatus_data->fb_notifier);
+	cancel_delayed_work_sync(&pstatus_data->check_status);
+	kfree(pstatus_data);
+	pr_debug("%s: DSI ctrl status work queue removed\n", __func__);
+}
+
+module_param(interval, uint, 0);
+MODULE_PARM_DESC(interval,
+		"Duration in milliseconds to send BTA command for checking"
+		"DSI status periodically");
+
+module_init(mdss_dsi_status_init);
+module_exit(mdss_dsi_status_exit);
+
+MODULE_LICENSE("GPL v2");