komeda display HWs have kinds of coefficient tables for various purposes
like gamma/degamma. ususally these tables are shared by multiple HW
component and have limited number.
Introduce komeda_coeffs_table/manager for describing and managing these
tables, like table reuse, racing.
Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.w...@arm.com>
---
drivers/gpu/drm/arm/display/komeda/Makefile | 1 +
.../drm/arm/display/komeda/komeda_coeffs.c | 119 ++++++++++++++++++
.../drm/arm/display/komeda/komeda_coeffs.h | 74 +++++++++++
3 files changed, 194 insertions(+)
create mode 100644 drivers/gpu/drm/arm/display/komeda/komeda_coeffs.c
create mode 100644 drivers/gpu/drm/arm/display/komeda/komeda_coeffs.h
diff --git a/drivers/gpu/drm/arm/display/komeda/Makefile
b/drivers/gpu/drm/arm/display/komeda/Makefile
index 5c3900c2e764..38aa5843c03a 100644
--- a/drivers/gpu/drm/arm/display/komeda/Makefile
+++ b/drivers/gpu/drm/arm/display/komeda/Makefile
@@ -8,6 +8,7 @@ komeda-y := \
komeda_drv.o \
komeda_dev.o \
komeda_format_caps.o \
+ komeda_coeffs.o \
komeda_color_mgmt.o \
komeda_pipeline.o \
komeda_pipeline_state.o \
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_coeffs.c
b/drivers/gpu/drm/arm/display/komeda/komeda_coeffs.c
new file mode 100644
index 000000000000..d9d35e23003c
--- /dev/null
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_coeffs.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) COPYRIGHT 2019 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.w...@arm.com>
+ *
+ */
+#include <linux/slab.h>
+#include "komeda_coeffs.h"
+
+static inline bool is_table_in_using(struct komeda_coeffs_table *table)
+{
+ return refcount_read(&table->refcount) > 1;
+}
+
+/* request a coeffs table for the coeffs data specified by argument coeffs */
+struct komeda_coeffs_table *
+komeda_coeffs_request(struct komeda_coeffs_manager *mgr, void *coeffs)
+{
+ struct komeda_coeffs_table *table;
+ u32 i;
+
+ mutex_lock(&mgr->mutex);
+
+ /* search table list to find if there is a in-using table with the
+ * same coefficient content, if find, reuse this table.
+ */
+ for (i = 0; i < mgr->n_tables; i++) {
+ table = mgr->tables[i];
+
+ /* skip the unused table */
+ if (!is_table_in_using(table))
+ continue;
+
+ if (!memcmp(table->coeffs, coeffs, mgr->coeffs_sz))
+ goto found;
+ }
+
+ /* can not reuse the existing in-using table, loop for a new one */
+ for (i = 0; i < mgr->n_tables; i++) {
+ table = mgr->tables[i];
+
+ if (!is_table_in_using(table)) {
+ memcpy(table->coeffs, coeffs, mgr->coeffs_sz);
+ table->needs_update = true;
+ goto found;
+ }
+ }
+
+ /* Since previous two search loop will directly goto found if found an
+ * available table, so once program ran here means search failed.
+ * clear the table to NULL, unlock(mgr->mutex) and return NULL.
+ */
+ table = NULL;
+
+found:
+ komeda_coeffs_get(table);
+ mutex_unlock(&mgr->mutex);
+ return table;
+}
+
+/* Add a coeffs table to manager */
+int komeda_coeffs_add(struct komeda_coeffs_manager *mgr,
+ u32 hw_id, u32 __iomem *reg,
+ void (*update)(struct komeda_coeffs_table *table))
+{
+ struct komeda_coeffs_table *table;
+
+ if (mgr->n_tables >= ARRAY_SIZE(mgr->tables))
+ return -ENOSPC;
+
+ table = kzalloc(sizeof(*table), GFP_KERNEL);
+ if (!table)
+ return -ENOMEM;
+
+ table->coeffs = kzalloc(mgr->coeffs_sz, GFP_KERNEL);
+ if (!table->coeffs) {
+ kfree(table);
+ return -ENOMEM;
+ }
+
+ refcount_set(&table->refcount, 1);
+ table->mgr = mgr;
+ table->hw_id = hw_id;
+ table->update = update;
+ table->reg = reg;
+
+ mgr->tables[mgr->n_tables++] = table;
+ return 0;
+}
+
+struct komeda_coeffs_manager *komeda_coeffs_create_manager(u32 coeffs_sz)
+{
+ struct komeda_coeffs_manager *mgr;
+
+ mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
+ if (!mgr)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_init(&mgr->mutex);
+ mgr->coeffs_sz = coeffs_sz;
+
+ return mgr;
+}
+
+void komeda_coeffs_destroy_manager(struct komeda_coeffs_manager *mgr)
+{
+ u32 i;
+
+ if (!mgr)
+ return;
+
+ for (i = 0; i < mgr->n_tables; i++) {
+ WARN_ON(is_table_in_using(mgr->tables[i]));
+ kfree(mgr->tables[i]->coeffs);
+ kfree(mgr->tables[i]);
+ }
+
+ kfree(mgr);
+}
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_coeffs.h
b/drivers/gpu/drm/arm/display/komeda/komeda_coeffs.h
new file mode 100644
index 000000000000..172ac2ea17ba
--- /dev/null
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_coeffs.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) COPYRIGHT 2019 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.w...@arm.com>
+ *
+ */
+#ifndef _KOMEDA_COEFFS_H_
+#define _KOMEDA_COEFFS_H_
+
+#include <linux/refcount.h>
+
+/* Komeda display HWs have kinds of coefficient tables for various purposes,
+ * like gamma/degamma. ususally these tables are shared by multiple HW
component
+ * and limited number.
+ * The komeda_coeffs_table/manager are imported for describing and managing
+ * these tables for table reuse and racing.
+ */
+struct komeda_coeffs_table {
+ struct komeda_coeffs_manager *mgr;
+ refcount_t refcount;
+ bool needs_update;
+ u32 hw_id;
+ void *coeffs;
+ u32 __iomem *reg;
+ void (*update)(struct komeda_coeffs_table *table);
+};
+
+struct komeda_coeffs_manager {
+ struct mutex mutex; /* for tables accessing */
+ u32 n_tables;
+ u32 coeffs_sz;
+ struct komeda_coeffs_table *tables[8];
+};
+
+static inline struct komeda_coeffs_table *
+komeda_coeffs_get(struct komeda_coeffs_table *table)
+{
+ if (table)
+ refcount_inc(&table->refcount);
+
+ return table;
+}
+
+static inline void __komeda_coeffs_put(struct komeda_coeffs_table *table)
+{
+ if (table)
+ refcount_dec(&table->refcount);
+}
+
+#define komeda_coeffs_put(table) \
+do { \
+ __komeda_coeffs_put(table); \
+ (table) = NULL; \
+} while (0)
+
+static inline void komeda_coeffs_update(struct komeda_coeffs_table *table)
+{
+ if (!table || !table->needs_update)
+ return;
+
+ table->update(table);
+ table->needs_update = false;
+}
+
+struct komeda_coeffs_manager *komeda_coeffs_create_manager(u32 coeffs_sz);
+void komeda_coeffs_destroy_manager(struct komeda_coeffs_manager *mgr);
+
+int komeda_coeffs_add(struct komeda_coeffs_manager *mgr,
+ u32 hw_id, u32 __iomem *reg,
+ void (*update)(struct komeda_coeffs_table *table));
+struct komeda_coeffs_table *
+komeda_coeffs_request(struct komeda_coeffs_manager *mgr, void *coeffs);
+
+#endif /*_KOMEDA_COEFFS_H_*/
--
2.20.1
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