ARM: Add interface for registering and calling firmware-specific operations

Some boards are running with secure firmware running in TrustZone secure
world, which changes the way some things have to be initialized.

This patch adds an interface for platforms to specify available firmware
operations and call them.

A wrapper macro, call_firmware_op(), checks if the operation is provided
and calls it if so, otherwise returns -ENOSYS to allow fallback to
legacy operation..

By default no operations are provided.

Example of use:

In code using firmware ops:

  __raw_writel(virt_to_phys(exynos4_secondary_startup),
               CPU1_BOOT_REG);

  /* Call Exynos specific smc call */
  if (call_firmware_op(cpu_boot, cpu) == -ENOSYS)
          cpu_boot_legacy(...); /* Try legacy way */

  gic_raise_softirq(cpumask_of(cpu), 1);

In board-/platform-specific code:

  static int platformX_do_idle(void)
  {
          /* tell platformX firmware to enter idle */
          return 0;
  }

  static int platformX_cpu_boot(int i)
  {
          /* tell platformX firmware to boot CPU i */
          return 0;
  }

  static const struct firmware_ops platformX_firmware_ops = {
          .do_idle      = exynos_do_idle,
          .cpu_boot     = exynos_cpu_boot,
          /* other operations not available on platformX */
  };

  static void __init board_init_early(void)
  {
          register_firmware_ops(&platformX_firmware_ops);
  }

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

3 files changed, 86 insertions, 0 deletions

diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index dc8dd0de5c0..45f7eae93ae 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -2,6 +2,8 @@
 # Makefile for the linux kernel.
 #
 
+obj-y				+= firmware.o
+
 obj-$(CONFIG_ICST)		+= icst.o
 obj-$(CONFIG_SA1111)		+= sa1111.o
 obj-$(CONFIG_PCI_HOST_VIA82C505) += via82c505.o
diff --git a/arch/arm/common/firmware.c b/arch/arm/common/firmware.c
new file mode 100644
index 00000000000..27ddccb1131
--- /dev/null
+++ b/arch/arm/common/firmware.c
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) 2012 Samsung Electronics.
+ * Kyungmin Park <kyungmin.park@samsung.com>
+ * Tomasz Figa <t.figa@samsung.com>
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/suspend.h>
+
+#include <asm/firmware.h>
+
+static const struct firmware_ops default_firmware_ops;
+
+const struct firmware_ops *firmware_ops = &default_firmware_ops;
diff --git a/arch/arm/include/asm/firmware.h b/arch/arm/include/asm/firmware.h
new file mode 100644
index 00000000000..15631300c23
--- /dev/null
+++ b/arch/arm/include/asm/firmware.h
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2012 Samsung Electronics.
+ * Kyungmin Park <kyungmin.park@samsung.com>
+ * Tomasz Figa <t.figa@samsung.com>
+ *
+ * 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.
+ */
+
+#ifndef __ASM_ARM_FIRMWARE_H
+#define __ASM_ARM_FIRMWARE_H
+
+#include <linux/bug.h>
+
+/*
+ * struct firmware_ops
+ *
+ * A structure to specify available firmware operations.
+ *
+ * A filled up structure can be registered with register_firmware_ops().
+ */
+struct firmware_ops {
+	/*
+	 * Enters CPU idle mode
+	 */
+	int (*do_idle)(void);
+	/*
+	 * Sets boot address of specified physical CPU
+	 */
+	int (*set_cpu_boot_addr)(int cpu, unsigned long boot_addr);
+	/*
+	 * Boots specified physical CPU
+	 */
+	int (*cpu_boot)(int cpu);
+	/*
+	 * Initializes L2 cache
+	 */
+	int (*l2x0_init)(void);
+};
+
+/* Global pointer for current firmware_ops structure, can't be NULL. */
+extern const struct firmware_ops *firmware_ops;
+
+/*
+ * call_firmware_op(op, ...)
+ *
+ * Checks if firmware operation is present and calls it,
+ * otherwise returns -ENOSYS
+ */
+#define call_firmware_op(op, ...)					\
+	((firmware_ops->op) ? firmware_ops->op(__VA_ARGS__) : (-ENOSYS))
+
+/*
+ * register_firmware_ops(ops)
+ *
+ * A function to register platform firmware_ops struct.
+ */
+static inline void register_firmware_ops(const struct firmware_ops *ops)
+{
+	BUG_ON(!ops);
+
+	firmware_ops = ops;
+}
+
+#endif