mx6: add support of multi-processor command

This allows u-boot to load different OS or Bare Metal application on
different cores of the i.MX6 SoC.
For example: running Android on cpu0 and a RT OS like QNX/FreeRTOS on cpu1.

Signed-off-by: Gabriel Huau <contact@huau-gabriel.fr>
Acked-by: Stefano Babic <sbabic@denx.de>

5 files changed, 108 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv7/mx6/Makefile b/arch/arm/cpu/armv7/mx6/Makefile
index 6dc9f8e..bf6effc 100644
--- a/arch/arm/cpu/armv7/mx6/Makefile
+++ b/arch/arm/cpu/armv7/mx6/Makefile
@@ -10,3 +10,4 @@
 obj-y	:= soc.o clock.o
 obj-$(CONFIG_SPL_BUILD)	     += ddr.o
 obj-$(CONFIG_SECURE_BOOT)    += hab.o
+obj-$(CONFIG_MP)             += mp.o
diff --git a/arch/arm/cpu/armv7/mx6/mp.c b/arch/arm/cpu/armv7/mx6/mp.c
new file mode 100644
index 0000000..9f034d6
--- /dev/null
+++ b/arch/arm/cpu/armv7/mx6/mp.c
@@ -0,0 +1,87 @@
+/*
+ * (C) Copyright 2014
+ * Gabriel Huau <contact@huau-gabriel.fr>
+ *
+ * (C) Copyright 2009 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/errno.h>
+#include <asm/arch/sys_proto.h>
+#include <asm/arch/imx-regs.h>
+
+#define MAX_CPUS 4
+static struct src *src = (struct src *)SRC_BASE_ADDR;
+
+static uint32_t cpu_reset_mask[MAX_CPUS] = {
+	0, /* We don't really want to modify the cpu0 */
+	SRC_SCR_CORE_1_RESET_MASK,
+	SRC_SCR_CORE_2_RESET_MASK,
+	SRC_SCR_CORE_3_RESET_MASK
+};
+
+static uint32_t cpu_ctrl_mask[MAX_CPUS] = {
+	0, /* We don't really want to modify the cpu0 */
+	SRC_SCR_CORE_1_ENABLE_MASK,
+	SRC_SCR_CORE_2_ENABLE_MASK,
+	SRC_SCR_CORE_3_ENABLE_MASK
+};
+
+int cpu_reset(int nr)
+{
+	/* Software reset of the CPU N */
+	src->scr |= cpu_reset_mask[nr];
+	return 0;
+}
+
+int cpu_status(int nr)
+{
+	printf("core %d => %d\n", nr, !!(src->scr & cpu_ctrl_mask[nr]));
+	return 0;
+}
+
+int cpu_release(int nr, int argc, char *const argv[])
+{
+	uint32_t boot_addr;
+
+	boot_addr = simple_strtoul(argv[0], NULL, 16);
+
+	switch (nr) {
+	case 1:
+		src->gpr3 = boot_addr;
+		break;
+	case 2:
+		src->gpr5 = boot_addr;
+		break;
+	case 3:
+		src->gpr7 = boot_addr;
+		break;
+	default:
+		return 1;
+	}
+
+	/* CPU N is ready to start */
+	src->scr |= cpu_ctrl_mask[nr];
+
+	return 0;
+}
+
+int is_core_valid(unsigned int core)
+{
+	uint32_t nr_cores = get_nr_cpus();
+
+	if (core > nr_cores)
+		return 0;
+
+	return 1;
+}
+
+int cpu_disable(int nr)
+{
+	/* Disable the CPU N */
+	src->scr &= ~cpu_ctrl_mask[nr];
+	return 0;
+}
diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c
index f2dee76..ac84a1f 100644
--- a/arch/arm/cpu/armv7/mx6/soc.c
+++ b/arch/arm/cpu/armv7/mx6/soc.c
@@ -35,6 +35,12 @@ struct scu_regs {
 	u32	fpga_rev;
 };
 
+u32 get_nr_cpus(void)
+{
+	struct scu_regs *scu = (struct scu_regs *)SCU_BASE_ADDR;
+	return readl(&scu->config) & 3;
+}
+
 u32 get_cpu_rev(void)
 {
 	struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR;
diff --git a/arch/arm/include/asm/arch-mx6/imx-regs.h b/arch/arm/include/asm/arch-mx6/imx-regs.h
index d4ce8a8..2631beb 100644
--- a/arch/arm/include/asm/arch-mx6/imx-regs.h
+++ b/arch/arm/include/asm/arch-mx6/imx-regs.h
@@ -324,6 +324,19 @@
 
 extern void imx_get_mac_from_fuse(int dev_id, unsigned char *mac);
 
+#define SRC_SCR_CORE_1_RESET_OFFSET     14
+#define SRC_SCR_CORE_1_RESET_MASK       (1<<SRC_SCR_CORE_1_RESET_OFFSET)
+#define SRC_SCR_CORE_2_RESET_OFFSET     15
+#define SRC_SCR_CORE_2_RESET_MASK       (1<<SRC_SCR_CORE_2_RESET_OFFSET)
+#define SRC_SCR_CORE_3_RESET_OFFSET     16
+#define SRC_SCR_CORE_3_RESET_MASK       (1<<SRC_SCR_CORE_3_RESET_OFFSET)
+#define SRC_SCR_CORE_1_ENABLE_OFFSET    22
+#define SRC_SCR_CORE_1_ENABLE_MASK      (1<<SRC_SCR_CORE_1_ENABLE_OFFSET)
+#define SRC_SCR_CORE_2_ENABLE_OFFSET    23
+#define SRC_SCR_CORE_2_ENABLE_MASK      (1<<SRC_SCR_CORE_2_ENABLE_OFFSET)
+#define SRC_SCR_CORE_3_ENABLE_OFFSET    24
+#define SRC_SCR_CORE_3_ENABLE_MASK      (1<<SRC_SCR_CORE_3_ENABLE_OFFSET)
+
 /* System Reset Controller (SRC) */
 struct src {
 	u32	scr;
diff --git a/arch/arm/include/asm/arch-mx6/sys_proto.h b/arch/arm/include/asm/arch-mx6/sys_proto.h
index 42d30f5..306d699 100644
--- a/arch/arm/include/asm/arch-mx6/sys_proto.h
+++ b/arch/arm/include/asm/arch-mx6/sys_proto.h
@@ -14,6 +14,7 @@
 #define soc_rev() (get_cpu_rev() & 0xFF)
 #define is_soc_rev(rev)        (soc_rev() - rev)
 
+u32 get_nr_cpus(void);
 u32 get_cpu_rev(void);
 
 /* returns MXC_CPU_ value */