mx7: psci: add basic psci support

1. add basic psci support for imx7 chip.
2. support cpu_on and cpu_off.
3. switch to non-secure mode when boot linux kernel.
4. set csu allow accessing all peripherial register in non-secure mode.

Signed-off-by: Frank Li <Frank.Li@freescale.com>
Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>

arch/arm/cpu/armv7/mx7/Makefile

@@ -6,3 +6,7 @@
 #
 
 obj-y	:= soc.o clock.o clock_slice.o
+
+ifdef CONFIG_ARMV7_PSCI
+obj-y  += psci-mx7.o psci.o
+endif

arch/arm/cpu/armv7/mx7/psci-mx7.c

@@ -0,0 +1,69 @@
+#include <asm/io.h>
+#include <asm/psci.h>
+#include <asm/arch/imx-regs.h>
+#include <common.h>
+
+#define __secure __attribute__((section("._secure.text")))
+
+#define GPC_CPU_PGC_SW_PDN_REQ	0xfc
+#define GPC_CPU_PGC_SW_PUP_REQ	0xf0
+#define GPC_PGC_C1		0x840
+
+#define BM_CPU_PGC_SW_PDN_PUP_REQ_CORE1_A7	0x2
+
+/* below is for i.MX7D */
+#define SRC_GPR1_MX7D		0x074
+#define SRC_A7RCR0		0x004
+#define SRC_A7RCR1		0x008
+
+#define BP_SRC_A7RCR0_A7_CORE_RESET0	0
+#define BP_SRC_A7RCR1_A7_CORE1_ENABLE	1
+
+static inline void imx_gpcv2_set_m_core_pgc(bool enable, u32 offset)
+{
+	writel(enable, GPC_IPS_BASE_ADDR + offset);
+}
+
+__secure void imx_gpcv2_set_core1_power(bool pdn)
+{
+	u32 reg = pdn ? GPC_CPU_PGC_SW_PUP_REQ : GPC_CPU_PGC_SW_PDN_REQ;
+	u32 val;
+
+	imx_gpcv2_set_m_core_pgc(true, GPC_PGC_C1);
+
+	val = readl(GPC_IPS_BASE_ADDR + reg);
+	val |= BM_CPU_PGC_SW_PDN_PUP_REQ_CORE1_A7;
+	writel(val, GPC_IPS_BASE_ADDR + reg);
+
+	while ((readl(GPC_IPS_BASE_ADDR + reg) &
+	       BM_CPU_PGC_SW_PDN_PUP_REQ_CORE1_A7) != 0)
+		;
+
+	imx_gpcv2_set_m_core_pgc(false, GPC_PGC_C1);
+}
+
+__secure void imx_enable_cpu_ca7(int cpu, bool enable)
+{
+	u32 mask, val;
+
+	mask = 1 << (BP_SRC_A7RCR1_A7_CORE1_ENABLE + cpu - 1);
+	val = readl(SRC_BASE_ADDR + SRC_A7RCR1);
+	val = enable ? val | mask : val & ~mask;
+	writel(val, SRC_BASE_ADDR + SRC_A7RCR1);
+}
+
+__secure int imx_cpu_on(int fn, int cpu, int pc)
+{
+	writel(pc, SRC_BASE_ADDR + cpu * 8 + SRC_GPR1_MX7D);
+	imx_gpcv2_set_core1_power(true);
+	imx_enable_cpu_ca7(cpu, true);
+	return 0;
+}
+
+__secure int imx_cpu_off(int cpu)
+{
+	imx_enable_cpu_ca7(cpu, false);
+	imx_gpcv2_set_core1_power(false);
+	writel(0, SRC_BASE_ADDR + cpu * 8 + SRC_GPR1_MX7D + 4);
+	return 0;
+}

arch/arm/cpu/armv7/mx7/psci.S

@@ -0,0 +1,54 @@
+#include <config.h>
+#include <linux/linkage.h>
+
+#include <asm/armv7.h>
+#include <asm/arch-armv7/generictimer.h>
+#include <asm/psci.h>
+
+	.pushsection ._secure.text, "ax"
+
+	.arch_extension sec
+
+	@ r1 = target CPU
+	@ r2 = target PC
+
+.globl	psci_arch_init
+psci_arch_init:
+	mov	r6, lr
+
+	bl	psci_get_cpu_id
+	bl	psci_get_cpu_stack_top
+	mov	sp, r0
+
+	bx	r6
+
+	@ r1 = target CPU
+	@ r2 = target PC
+
+.globl psci_cpu_on
+psci_cpu_on:
+	push	{lr}
+
+	mov	r0, r1
+	bl	psci_get_cpu_stack_top
+	str	r2, [r0]
+	dsb
+
+	ldr	r2, =psci_cpu_entry
+	bl	imx_cpu_on
+
+	pop	{pc}
+
+.globl psci_cpu_off
+psci_cpu_off:
+
+	bl	psci_cpu_off_common
+	bl	psci_get_cpu_id
+	bl	imx_cpu_off
+
+1: 	wfi
+	b 1b
+
+	.globl psci_text_end
+psci_text_end:
+	.popsection

arch/arm/cpu/armv7/mx7/soc.c

@@ -122,10 +122,19 @@ u32 __weak get_board_rev(void)
 }
 #endif
 
+/* enable all periherial can be accessed in nosec mode */
+static void init_csu(void)
+{
+	int i = 0;
+	for (i = 0; i < CSU_NUM_REGS; i++)
+		writel(CSU_INIT_SEC_LEVEL0, CSU_IPS_BASE_ADDR + i * 4);
+}
+
 int arch_cpu_init(void)
 {
 	init_aips();
 
+	init_csu();
 	/* Disable PDE bit of WMCR register */
 	imx_set_wdog_powerdown(false);
 

arch/arm/include/asm/arch-mx7/imx-regs.h

@@ -866,6 +866,9 @@ struct cspi_regs {
 	ECSPI3_BASE_ADDR, \
 	ECSPI4_BASE_ADDR
 
+#define CSU_INIT_SEC_LEVEL0	0x00FF00FF
+#define CSU_NUM_REGS		64
+
 struct ocotp_regs {
 	u32 ctrl;
 	u32 ctrl_set;