[PATCH] drm/komeda: Adds error event print functionality

["Lowry Li (Arm Technology China)" <Lowry.Li@arm.com>]

Adds to print the event message when error happens and the same event
will not be printed until next vsync.

Signed-off-by: Lowry Li (Arm Technology China) <lowry.li@arm.com>
---
 drivers/gpu/drm/arm/display/komeda/Makefile       |   1 +
 drivers/gpu/drm/arm/display/komeda/komeda_dev.h   |  13 ++
 drivers/gpu/drm/arm/display/komeda/komeda_event.c | 144 ++++++++++++++++++++++
 drivers/gpu/drm/arm/display/komeda/komeda_kms.c   |   2 +
 4 files changed, 160 insertions(+)
 create mode 100644 drivers/gpu/drm/arm/display/komeda/komeda_event.c

diff --git a/drivers/gpu/drm/arm/display/komeda/Makefile b/drivers/gpu/drm/arm/display/komeda/Makefile
index 38aa584..3f53d2d 100644
--- a/drivers/gpu/drm/arm/display/komeda/Makefile
+++ b/drivers/gpu/drm/arm/display/komeda/Makefile
@@ -7,6 +7,7 @@ ccflags-y := \
 komeda-y := \
 	komeda_drv.o \
 	komeda_dev.o \
+	komeda_event.o \
 	komeda_format_caps.o \
 	komeda_coeffs.o \
 	komeda_color_mgmt.o \
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
index 096f9f7..e863ec3 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
@@ -40,6 +40,17 @@
 #define KOMEDA_ERR_TTNG			BIT_ULL(30)
 #define KOMEDA_ERR_TTF			BIT_ULL(31)
 
+#define KOMEDA_ERR_EVENTS	\
+	(KOMEDA_EVENT_URUN	| KOMEDA_EVENT_IBSY	| KOMEDA_EVENT_OVR |\
+	KOMEDA_ERR_TETO		| KOMEDA_ERR_TEMR	| KOMEDA_ERR_TITR |\
+	KOMEDA_ERR_CPE		| KOMEDA_ERR_CFGE	| KOMEDA_ERR_AXIE |\
+	KOMEDA_ERR_ACE0		| KOMEDA_ERR_ACE1	| KOMEDA_ERR_ACE2 |\
+	KOMEDA_ERR_ACE3		| KOMEDA_ERR_DRIFTTO	| KOMEDA_ERR_FRAMETO |\
+	KOMEDA_ERR_ZME		| KOMEDA_ERR_MERR	| KOMEDA_ERR_TCF |\
+	KOMEDA_ERR_TTNG		| KOMEDA_ERR_TTF)
+
+#define KOMEDA_WARN_EVENTS	KOMEDA_ERR_CSCE
+
 /* malidp device id */
 enum {
 	MALI_D71 = 0,
@@ -207,6 +218,8 @@ struct komeda_dev {
 
 struct komeda_dev *dev_to_mdev(struct device *dev);
 
+void komeda_print_events(struct komeda_events *evts);
+
 int komeda_dev_resume(struct komeda_dev *mdev);
 int komeda_dev_suspend(struct komeda_dev *mdev);
 #endif /*_KOMEDA_DEV_H_*/
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_event.c b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
new file mode 100644
index 0000000..309dbe2
--- /dev/null
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) COPYRIGHT 2019 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.wang@arm.com>
+ *
+ */
+#include <drm/drm_print.h>
+
+#include "komeda_dev.h"
+
+struct komeda_str {
+	char *str;
+	u32 sz;
+	u32 len;
+};
+
+/* return 0 on success,  < 0 on no space.
+ */
+static int komeda_sprintf(struct komeda_str *str, const char *fmt, ...)
+{
+	va_list args;
+	int num, free_sz;
+	int err;
+
+	free_sz = str->sz - str->len;
+	if (free_sz <= 0)
+		return -ENOSPC;
+
+	va_start(args, fmt);
+
+	num = vsnprintf(str->str + str->len, free_sz, fmt, args);
+
+	va_end(args);
+
+	if (num <= free_sz) {
+		str->len += num;
+		err = 0;
+	} else {
+		str->len = str->sz;
+		err = -ENOSPC;
+	}
+
+	return err;
+}
+
+static void evt_sprintf(struct komeda_str *str, u64 evt, const char *msg)
+{
+	if (evt)
+		komeda_sprintf(str, msg);
+}
+
+static void evt_str(struct komeda_str *str, u64 events)
+{
+	if (events == 0ULL) {
+		evt_sprintf(str, 1, "None");
+		return;
+	}
+
+	evt_sprintf(str, events & KOMEDA_EVENT_VSYNC, "VSYNC|");
+	evt_sprintf(str, events & KOMEDA_EVENT_FLIP, "FLIP|");
+	evt_sprintf(str, events & KOMEDA_EVENT_EOW, "EOW|");
+	evt_sprintf(str, events & KOMEDA_EVENT_MODE, "OP-MODE|");
+
+	evt_sprintf(str, events & KOMEDA_EVENT_URUN, "UNDERRUN|");
+	evt_sprintf(str, events & KOMEDA_EVENT_OVR, "OVERRUN|");
+
+	/* GLB error */
+	evt_sprintf(str, events & KOMEDA_ERR_MERR, "MERR|");
+	evt_sprintf(str, events & KOMEDA_ERR_FRAMETO, "FRAMETO|");
+
+	/* DOU error */
+	evt_sprintf(str, events & KOMEDA_ERR_DRIFTTO, "DRIFTTO|");
+	evt_sprintf(str, events & KOMEDA_ERR_FRAMETO, "FRAMETO|");
+	evt_sprintf(str, events & KOMEDA_ERR_TETO, "TETO|");
+	evt_sprintf(str, events & KOMEDA_ERR_CSCE, "CSCE|");
+
+	/* LPU errors or events */
+	evt_sprintf(str, events & KOMEDA_EVENT_IBSY, "IBSY|");
+	evt_sprintf(str, events & KOMEDA_ERR_AXIE, "AXIE|");
+	evt_sprintf(str, events & KOMEDA_ERR_ACE0, "ACE0|");
+	evt_sprintf(str, events & KOMEDA_ERR_ACE1, "ACE1|");
+	evt_sprintf(str, events & KOMEDA_ERR_ACE2, "ACE2|");
+	evt_sprintf(str, events & KOMEDA_ERR_ACE3, "ACE3|");
+
+	/* LPU TBU errors*/
+	evt_sprintf(str, events & KOMEDA_ERR_TCF, "TCF|");
+	evt_sprintf(str, events & KOMEDA_ERR_TTNG, "TTNG|");
+	evt_sprintf(str, events & KOMEDA_ERR_TITR, "TITR|");
+	evt_sprintf(str, events & KOMEDA_ERR_TEMR, "TEMR|");
+	evt_sprintf(str, events & KOMEDA_ERR_TTF, "TTF|");
+
+	/* CU errors*/
+	evt_sprintf(str, events & KOMEDA_ERR_CPE, "COPROC|");
+	evt_sprintf(str, events & KOMEDA_ERR_ZME, "ZME|");
+	evt_sprintf(str, events & KOMEDA_ERR_CFGE, "CFGE|");
+	evt_sprintf(str, events & KOMEDA_ERR_TEMR, "TEMR|");
+
+	if (str->len > 0 && (str->str[str->len - 1] == '|')) {
+		str->str[str->len - 1] = 0;
+		str->len--;
+	}
+}
+
+static bool is_new_frame(struct komeda_events *a)
+{
+	return (a->pipes[0] | a->pipes[1]) & KOMEDA_EVENT_FLIP;
+}
+
+void komeda_print_events(struct komeda_events *evts)
+{
+	u64 print_evts = KOMEDA_ERR_EVENTS;
+	static bool en_print = true;
+
+	/* reduce the same msg print, only print the first evt for one frame */
+	if (evts->global || is_new_frame(evts))
+		en_print = true;
+	if (!en_print)
+		return;
+
+#ifdef DEBUG
+	print_evts |= KOMEDA_WARN_EVENTS;
+#endif
+
+	if ((evts->global | evts->pipes[0] | evts->pipes[1]) & print_evts) {
+		#define STR_SZ		128
+		char msg[STR_SZ];
+		struct komeda_str str;
+
+		str.str = msg;
+		str.sz  = STR_SZ;
+		str.len = 0;
+
+		komeda_sprintf(&str, "gcu: ");
+		evt_str(&str, evts->global);
+		komeda_sprintf(&str, ", pipes[0]: ");
+		evt_str(&str, evts->pipes[0]);
+		komeda_sprintf(&str, ", pipes[1]: ");
+		evt_str(&str, evts->pipes[1]);
+
+		DRM_ERROR("err detect: %s\n", msg);
+
+		en_print = false;
+	}
+}
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
index 647bce5..1462bac 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
@@ -47,6 +47,8 @@ static irqreturn_t komeda_kms_irq_handler(int irq, void *data)
 	memset(&evts, 0, sizeof(evts));
 	status = mdev->funcs->irq_handler(mdev, &evts);
 
+	komeda_print_events(&evts);
+
 	/* Notify the crtc to handle the events */
 	for (i = 0; i < kms->n_crtcs; i++)
 		komeda_crtc_handle_event(&kms->crtcs[i], &evts);
-- 
1.9.1