1 files changed, 159 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/cpu-imx5.c b/arch/arm/mach-imx/cpu-imx5.c
new file mode 100644
index 000000000..a67c89bf1
--- /dev/null
+++ b/arch/arm/mach-imx/cpu-imx5.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2008-2010 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This file contains the CPU initialization code.
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include "hardware.h"
+#include "common.h"
+
+static int mx5_cpu_rev = -1;
+
+#define IIM_SREV 0x24
+
+static u32 imx5_read_srev_reg(const char *compat)
+{
+	void __iomem *iim_base;
+	struct device_node *np;
+	u32 srev;
+
+	np = of_find_compatible_node(NULL, NULL, compat);
+	iim_base = of_iomap(np, 0);
+	of_node_put(np);
+	WARN_ON(!iim_base);
+
+	srev = readl(iim_base + IIM_SREV) & 0xff;
+
+	iounmap(iim_base);
+
+	return srev;
+}
+
+static int get_mx51_srev(void)
+{
+	u32 rev = imx5_read_srev_reg("fsl,imx51-iim");
+
+	switch (rev) {
+	case 0x0:
+		return IMX_CHIP_REVISION_2_0;
+	case 0x10:
+		return IMX_CHIP_REVISION_3_0;
+	default:
+		return IMX_CHIP_REVISION_UNKNOWN;
+	}
+}
+
+/*
+ * Returns:
+ *	the silicon revision of the cpu
+ */
+int mx51_revision(void)
+{
+	if (mx5_cpu_rev == -1)
+		mx5_cpu_rev = get_mx51_srev();
+
+	return mx5_cpu_rev;
+}
+EXPORT_SYMBOL(mx51_revision);
+
+#ifdef CONFIG_NEON
+
+/*
+ * All versions of the silicon before Rev. 3 have broken NEON implementations.
+ * Dependent on link order - so the assumption is that vfp_init is called
+ * before us.
+ */
+int __init mx51_neon_fixup(void)
+{
+	if (mx51_revision() < IMX_CHIP_REVISION_3_0 &&
+			(elf_hwcap & HWCAP_NEON)) {
+		elf_hwcap &= ~HWCAP_NEON;
+		pr_info("Turning off NEON support, detected broken NEON implementation\n");
+	}
+	return 0;
+}
+
+#endif
+
+static int get_mx53_srev(void)
+{
+	u32 rev = imx5_read_srev_reg("fsl,imx53-iim");
+
+	switch (rev) {
+	case 0x0:
+		return IMX_CHIP_REVISION_1_0;
+	case 0x2:
+		return IMX_CHIP_REVISION_2_0;
+	case 0x3:
+		return IMX_CHIP_REVISION_2_1;
+	default:
+		return IMX_CHIP_REVISION_UNKNOWN;
+	}
+}
+
+/*
+ * Returns:
+ *	the silicon revision of the cpu
+ */
+int mx53_revision(void)
+{
+	if (mx5_cpu_rev == -1)
+		mx5_cpu_rev = get_mx53_srev();
+
+	return mx5_cpu_rev;
+}
+EXPORT_SYMBOL(mx53_revision);
+
+#define ARM_GPC		0x4
+#define DBGEN		BIT(16)
+
+/*
+ * This enables the DBGEN bit in ARM_GPC register, which is
+ * required for accessing some performance counter features.
+ * Technically it is only required while perf is used, but to
+ * keep the source code simple we just enable it all the time
+ * when the kernel configuration allows using the feature.
+ */
+void __init imx5_pmu_init(void)
+{
+	void __iomem *tigerp_base;
+	struct device_node *np;
+	u32 gpc;
+
+	if (!IS_ENABLED(CONFIG_ARM_PMU))
+		return;
+
+	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a8-pmu");
+	if (!np)
+		return;
+
+	if (!of_property_read_bool(np, "secure-reg-access"))
+		goto exit;
+
+	of_node_put(np);
+
+	np = of_find_compatible_node(NULL, NULL, "fsl,imx51-tigerp");
+	if (!np)
+		return;
+
+	tigerp_base = of_iomap(np, 0);
+	if (!tigerp_base)
+		goto exit;
+
+	gpc = readl_relaxed(tigerp_base + ARM_GPC);
+	gpc |= DBGEN;
+	writel_relaxed(gpc, tigerp_base + ARM_GPC);
+	iounmap(tigerp_base);
+exit:
+	of_node_put(np);
+
+}