ARM: tegra: clock: Support variable iso share with emc usage

Added mechanism to determine maximum allowed iso bandwidth share
depending on emc usage. Each use case is identified by a combination
of shared emc user clocks turned on. The list of use cases and the
respective iso share percentage is to be provided by chip specific
tables.

This commit only added variable iso share APIs and emc shared users
enumeration. No platform specific tables are specified, and APIs are
not used.

Bug 1253271

Change-Id: If08ce2c0e180de600ccb28b91381066543659180
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/212911
(cherry-picked from commit 5e971cd9a173d6418287e091275c8357bd169dd0)
Reviewed-on: http://git-master/r/217117
Reviewed-by: Jon Mayo <jmayo@nvidia.com>
Reviewed-by: Krishna Reddy <vdumpa@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>

1 files changed, 145 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/tegra_emc.c b/arch/arm/mach-tegra/tegra_emc.c
new file mode 100644
index 000000000000..54c1cb66a73a
--- /dev/null
+++ b/arch/arm/mach-tegra/tegra_emc.c
@@ -0,0 +1,145 @@
+/*
+ * arch/arm/mach-tegra/tegra_emc.c
+ *
+ * Copyright (c) 2013, NVIDIA CORPORATION.  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 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include "tegra_emc.h"
+
+static u8 emc_iso_share = 100;
+
+static struct emc_iso_usage emc_usage_table[TEGRA_EMC_ISO_USE_CASES_MAX_NUM];
+
+
+void __init tegra_emc_iso_usage_table_init(struct emc_iso_usage *table,
+					   int size)
+{
+	size = min(size, TEGRA_EMC_ISO_USE_CASES_MAX_NUM);
+
+	if (size && table)
+		memcpy(emc_usage_table, table,
+		       size * sizeof(struct emc_iso_usage));
+}
+
+u8 tegra_emc_get_iso_share(u32 usage_flags)
+{
+	int i;
+	u8 iso_share = 100;
+
+	if (usage_flags) {
+		for (i = 0; i < TEGRA_EMC_ISO_USE_CASES_MAX_NUM; i++) {
+			struct emc_iso_usage *iso_usage = &emc_usage_table[i];
+			u32 flags = iso_usage->emc_usage_flags;
+			u8 share = iso_usage->iso_usage_share;
+
+			if (!flags)
+				continue;
+			if (!share) {
+				WARN(1, "%s: entry %d: iso_share 0\n",
+				     __func__, i);
+				continue;
+			}
+
+			if ((flags & usage_flags) == flags)
+				iso_share = min(iso_share,
+						iso_usage->iso_usage_share);
+		}
+	}
+	emc_iso_share = iso_share;
+	return iso_share;
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+#define USER_NAME(module) \
+[EMC_USER_##module] = #module
+
+static const char *emc_user_names[EMC_USER_NUM] = {
+	USER_NAME(DC),
+	USER_NAME(VI),
+	USER_NAME(MSENC),
+	USER_NAME(2D),
+	USER_NAME(3D),
+};
+
+static int emc_usage_table_show(struct seq_file *s, void *data)
+{
+	int i, j;
+
+	seq_printf(s, "EMC USAGE\t\tISO SHARE %%\n");
+
+	for (i = 0; i < TEGRA_EMC_ISO_USE_CASES_MAX_NUM; i++) {
+		u32 flags = emc_usage_table[i].emc_usage_flags;
+		u8 share = emc_usage_table[i].iso_usage_share;
+		bool first = false;
+
+		seq_printf(s, "[%d]: ", i);
+		if (!flags) {
+			seq_printf(s, "reserved\n");
+			continue;
+		}
+
+		for (j = 0; j < EMC_USER_NUM; j++) {
+			u32 mask = 0x1 << j;
+			if (!(flags & mask))
+				continue;
+			seq_printf(s, "%s%s", first ? "+" : "",
+				   emc_user_names[j]);
+			first = true;
+		}
+		seq_printf(s, "\r\t\t\t= %d\n", share);
+	}
+	return 0;
+}
+
+static int emc_usage_table_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, emc_usage_table_show, inode->i_private);
+}
+
+static const struct file_operations emc_usage_table_fops = {
+	.open		= emc_usage_table_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+int __init tegra_emc_iso_usage_debugfs_init(struct dentry *emc_debugfs_root)
+{
+	struct dentry *d;
+
+	d = debugfs_create_file("emc_usage_table", S_IRUGO, emc_debugfs_root,
+		NULL, &emc_usage_table_fops);
+	if (!d)
+		return -ENOMEM;
+
+	d = debugfs_create_u8("emc_iso_share", S_IRUGO, emc_debugfs_root,
+			      &emc_iso_share);
+	if (!d)
+		return -ENOMEM;
+
+	return 0;
+}
+#endif