ARM: tegra: Add speedo-based process identification

Detect CPU and core process ID by checking speedo corner tables.
This can provide a more accurate process ID.

Signed-off-by: Danny Huang <dahuang@nvidia.com>
[swarren s/Tegra2/Tegra20/ in log print]
Signed-off-by: Stephen Warren <swarren@nvidia.com>

1 files changed, 109 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/tegra20_speedo.c b/arch/arm/mach-tegra/tegra20_speedo.c
new file mode 100644
index 000000000000..fa6eb570623f
--- /dev/null
+++ b/arch/arm/mach-tegra/tegra20_speedo.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/bug.h>
+
+#include "fuse.h"
+
+#define CPU_SPEEDO_LSBIT		20
+#define CPU_SPEEDO_MSBIT		29
+#define CPU_SPEEDO_REDUND_LSBIT		30
+#define CPU_SPEEDO_REDUND_MSBIT		39
+#define CPU_SPEEDO_REDUND_OFFS	(CPU_SPEEDO_REDUND_MSBIT - CPU_SPEEDO_MSBIT)
+
+#define CORE_SPEEDO_LSBIT		40
+#define CORE_SPEEDO_MSBIT		47
+#define CORE_SPEEDO_REDUND_LSBIT	48
+#define CORE_SPEEDO_REDUND_MSBIT	55
+#define CORE_SPEEDO_REDUND_OFFS	(CORE_SPEEDO_REDUND_MSBIT - CORE_SPEEDO_MSBIT)
+
+#define SPEEDO_MULT			4
+
+#define PROCESS_CORNERS_NUM		4
+
+#define SPEEDO_ID_SELECT_0(rev)		((rev) <= 2)
+#define SPEEDO_ID_SELECT_1(sku)		\
+	(((sku) != 20) && ((sku) != 23) && ((sku) != 24) && \
+	 ((sku) != 27) && ((sku) != 28))
+
+enum {
+	SPEEDO_ID_0,
+	SPEEDO_ID_1,
+	SPEEDO_ID_2,
+	SPEEDO_ID_COUNT,
+};
+
+static const u32 cpu_process_speedos[][PROCESS_CORNERS_NUM] = {
+	{315, 366, 420, UINT_MAX},
+	{303, 368, 419, UINT_MAX},
+	{316, 331, 383, UINT_MAX},
+};
+
+static const u32 core_process_speedos[][PROCESS_CORNERS_NUM] = {
+	{165, 195, 224, UINT_MAX},
+	{165, 195, 224, UINT_MAX},
+	{165, 195, 224, UINT_MAX},
+};
+
+void tegra20_init_speedo_data(void)
+{
+	u32 reg;
+	u32 val;
+	int i;
+
+	BUILD_BUG_ON(ARRAY_SIZE(cpu_process_speedos) != SPEEDO_ID_COUNT);
+	BUILD_BUG_ON(ARRAY_SIZE(core_process_speedos) != SPEEDO_ID_COUNT);
+
+	if (SPEEDO_ID_SELECT_0(tegra_revision))
+		tegra_soc_speedo_id = SPEEDO_ID_0;
+	else if (SPEEDO_ID_SELECT_1(tegra_sku_id))
+		tegra_soc_speedo_id = SPEEDO_ID_1;
+	else
+		tegra_soc_speedo_id = SPEEDO_ID_2;
+
+	val = 0;
+	for (i = CPU_SPEEDO_MSBIT; i >= CPU_SPEEDO_LSBIT; i--) {
+		reg = tegra_spare_fuse(i) |
+			tegra_spare_fuse(i + CPU_SPEEDO_REDUND_OFFS);
+		val = (val << 1) | (reg & 0x1);
+	}
+	val = val * SPEEDO_MULT;
+	pr_debug("%s CPU speedo value %u\n", __func__, val);
+
+	for (i = 0; i < (PROCESS_CORNERS_NUM - 1); i++) {
+		if (val <= cpu_process_speedos[tegra_soc_speedo_id][i])
+			break;
+	}
+	tegra_cpu_process_id = i;
+
+	val = 0;
+	for (i = CORE_SPEEDO_MSBIT; i >= CORE_SPEEDO_LSBIT; i--) {
+		reg = tegra_spare_fuse(i) |
+			tegra_spare_fuse(i + CORE_SPEEDO_REDUND_OFFS);
+		val = (val << 1) | (reg & 0x1);
+	}
+	val = val * SPEEDO_MULT;
+	pr_debug("%s Core speedo value %u\n", __func__, val);
+
+	for (i = 0; i < (PROCESS_CORNERS_NUM - 1); i++) {
+		if (val <= core_process_speedos[tegra_soc_speedo_id][i])
+			break;
+	}
+	tegra_core_process_id = i;
+
+	pr_info("Tegra20 Soc Speedo ID %d", tegra_soc_speedo_id);
+}