nds32/ag102: add ag102 soc support

Add lowlevel ag102 soc support.

Signed-off-by: Macpaul Lin <macpaul@andestech.com>
diff --git a/arch/nds32/cpu/n1213/ag102/lowlevel_init.S b/arch/nds32/cpu/n1213/ag102/lowlevel_init.S
new file mode 100644
index 0000000..d842afa
--- /dev/null
+++ b/arch/nds32/cpu/n1213/ag102/lowlevel_init.S
@@ -0,0 +1,297 @@
+/*
+ * Copyright (C) 2011 Andes Technology Corporation
+ * Macpaul Lin, Andes Technology Corporation <macpaul@andestech.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+.text
+
+#include <common.h>
+#include <config.h>
+
+#include <asm/macro.h>
+#include <generated/asm-offsets.h>
+
+/*
+ * parameters for Synopsys DWC DDR2/DDR1 Memory Controller
+ */
+#define DDR2C_BASE_A		(CONFIG_DWCDDR21MCTL_BASE)
+#define DDR2C_CCR_A		(DDR2C_BASE_A + DWCDDR21MCTL_CCR)
+#define DDR2C_DCR_A		(DDR2C_BASE_A + DWCDDR21MCTL_DCR)
+#define DDR2C_IOCR_A		(DDR2C_BASE_A + DWCDDR21MCTL_IOCR)
+#define DDR2C_CSR_A		(DDR2C_BASE_A + DWCDDR21MCTL_CSR)
+#define DDR2C_DRR_A		(DDR2C_BASE_A + DWCDDR21MCTL_DRR)
+#define DDR2C_DLLCR0_A		(DDR2C_BASE_A + DWCDDR21MCTL_DLLCR0)
+#define DDR2C_DLLCR1_A		(DDR2C_BASE_A + DWCDDR21MCTL_DLLCR1)
+#define DDR2C_DLLCR2_A		(DDR2C_BASE_A + DWCDDR21MCTL_DLLCR2)
+#define DDR2C_DLLCR3_A		(DDR2C_BASE_A + DWCDDR21MCTL_DLLCR3)
+#define DDR2C_DLLCR4_A		(DDR2C_BASE_A + DWCDDR21MCTL_DLLCR4)
+#define DDR2C_DLLCR5_A		(DDR2C_BASE_A + DWCDDR21MCTL_DLLCR5)
+#define DDR2C_DLLCR6_A		(DDR2C_BASE_A + DWCDDR21MCTL_DLLCR6)
+#define DDR2C_DLLCR7_A		(DDR2C_BASE_A + DWCDDR21MCTL_DLLCR7)
+#define DDR2C_DLLCR8_A		(DDR2C_BASE_A + DWCDDR21MCTL_DLLCR8)
+#define DDR2C_DLLCR9_A		(DDR2C_BASE_A + DWCDDR21MCTL_DLLCR9)
+#define DDR2C_RSLR0_A		(DDR2C_BASE_A + DWCDDR21MCTL_RSLR0)
+#define DDR2C_RDGR0_A		(DDR2C_BASE_A + DWCDDR21MCTL_RDGR0)
+#define DDR2C_DTAR_A		(DDR2C_BASE_A + DWCDDR21MCTL_DTAR)
+#define DDR2C_MR_A		(DDR2C_BASE_A + DWCDDR21MCTL_MR)
+
+#define DDR2C_CCR_D		CONFIG_SYS_DWCDDR21MCTL_CCR
+#define DDR2C_CCR_D2		CONFIG_SYS_DWCDDR21MCTL_CCR2
+#define DDR2C_DCR_D		CONFIG_SYS_DWCDDR21MCTL_DCR
+#define DDR2C_IOCR_D		CONFIG_SYS_DWCDDR21MCTL_IOCR
+#define DDR2C_CSR_D		CONFIG_SYS_DWCDDR21MCTL_CSR
+#define DDR2C_DRR_D		CONFIG_SYS_DWCDDR21MCTL_DRR
+#define DDR2C_RSLR0_D		CONFIG_SYS_DWCDDR21MCTL_RSLR0
+#define DDR2C_RDGR0_D		CONFIG_SYS_DWCDDR21MCTL_RDGR0
+#define DDR2C_DTAR_D		CONFIG_SYS_DWCDDR21MCTL_DTAR
+#define DDR2C_MR_D		CONFIG_SYS_DWCDDR21MCTL_MR
+
+#define DDR2C_DLLCR0_D	CONFIG_SYS_DWCDDR21MCTL_DLLCR0	/* 0-9 are same */
+
+/*
+ * parameters for the ahbc controller
+ */
+#define AHBC_CR_A		(CONFIG_FTAHBC020S_BASE + FTAHBC020S_CR)
+#define AHBC_BSR6_A	(CONFIG_FTAHBC020S_BASE + FTAHBC020S_SLAVE_BSR_6)
+
+#define AHBC_BSR6_D		CONFIG_SYS_FTAHBC020S_SLAVE_BSR_6
+
+/*
+ * parameters for the ANDES PCU controller
+ */
+#define PCU_PCS4_A		(CONFIG_ANDES_PCU_BASE + ANDES_PCU_PCS4)
+#define PCU_PCS4_D		CONFIG_SYS_ANDES_CPU_PCS4
+
+/*
+ * numeric 7 segment display
+ */
+.macro	led, num
+	write32	CONFIG_DEBUG_LED, \num
+.endm
+
+/*
+ * Waiting for SDRAM to set up
+ */
+/*
+.macro	wait_sdram
+	li	$r0, DDR2C_CSR_A
+1:
+	lwi	$r1, [$r0+FTSDMC021_CR2]
+	bnez	$r1, 1b
+.endm
+*/
+
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+.globl	lowlevel_init
+lowlevel_init:
+	move	$r10, $lp
+
+	/* U200 */
+!	led	0x00
+!	jal	scale_to_500mhz
+
+	led	0x10
+	jal	mem_init
+
+	led	0x20
+	jal	remap
+
+	led	0x30
+	ret	$r10
+
+scale_to_500mhz:
+	move	$r11, $lp
+
+	/*
+	 * scale to 500Mhz
+	 */
+	led	0x01
+	write32	PCU_PCS4_A, 0x1102000f			! save data to PCS4
+
+	move	$lp, $r11
+	ret
+
+mem_init:
+	move	$r11, $lp
+
+	/*
+	 * config AHB Controller
+	 */
+	led	0x12
+	write32	AHBC_BSR6_A, AHBC_BSR6_D
+
+	/*
+	 * config Synopsys DWC DDR2/DDR1 Memory Controller
+	 */
+ddr2c_init:
+set_dcr:
+	led	0x14
+	write32	DDR2C_DCR_A, DDR2C_DCR_D			! 0x000020d4
+
+auto_sizing:
+	/*
+	 * ebios: $r10->$r7, $r11->$r8, $r12->$r9, $r13->$r12, $r14->$r13
+	 */
+set_iocr:
+	led	0x19
+	write32 DDR2C_IOCR_A, DDR2C_IOCR_D
+set_drr:
+	led	0x16
+	write32	DDR2C_DRR_A, DDR2C_DRR_D			! 0x00034812
+set_dllcr:
+	led	0x18
+	write32 DDR2C_DLLCR0_A, DDR2C_DLLCR0_D
+	write32 DDR2C_DLLCR1_A, DDR2C_DLLCR0_D
+	write32 DDR2C_DLLCR2_A, DDR2C_DLLCR0_D
+	write32 DDR2C_DLLCR3_A, DDR2C_DLLCR0_D
+	write32 DDR2C_DLLCR4_A, DDR2C_DLLCR0_D
+	write32 DDR2C_DLLCR5_A, DDR2C_DLLCR0_D
+	write32 DDR2C_DLLCR6_A, DDR2C_DLLCR0_D
+	write32 DDR2C_DLLCR7_A, DDR2C_DLLCR0_D
+	write32 DDR2C_DLLCR8_A, DDR2C_DLLCR0_D
+	write32 DDR2C_DLLCR9_A, DDR2C_DLLCR0_D
+set_rslr0:
+	write32 DDR2C_RSLR0_A, DDR2C_RSLR0_D			! 0x00000040
+set_rdgr0:
+	write32 DDR2C_RDGR0_A, DDR2C_RDGR0_D			! 0x000055cf
+set_dtar:
+	led	0x15
+	write32	DDR2C_DTAR_A, DDR2C_DTAR_D			! 0x00100000
+set_mode:
+	led	0x17
+	write32	DDR2C_MR_A, DDR2C_MR_D				! 0x00000852
+set_ccr:
+	write32 DDR2C_CCR_A, DDR2C_CCR_D
+
+#ifdef TRIGGER_INIT:
+trigger_init:
+	write32 DDR2C_CCR_A, DDR2C_CCR_D			! 0x80020000
+
+	/* Wait for ddr init state to be set */
+	msync	ALL
+	isb
+
+	/* Wait until the config initialization is finish */
+1:
+	la	$r4, DDR2C_CSR_A
+	lwi	$r5, [$r4]
+	srli	$r5, $r5, 23
+	bnez	$r5, 1b
+#endif
+
+data_training:
+!	write32	DDR2C_CCR_A, DDR2C_CCR_D2			! 0x40020004
+
+	/* Wait for ddr init state to be set */
+	msync	ALL
+	isb
+
+	/* wait until the ddr data trainning is complete */
+1:
+	la	$r4, DDR2C_CSR_A
+	lwi	$r5, [$r4]
+	srli	$r6, $r5, 23
+	bnez	$r6, 1b
+
+	lwi	$r1, [$r4]
+	srli	$r6, $r5, 20
+	li	$r5, 0x00ffffff
+	swi	$r1, [$r4]
+	bnez	$r6, ddr2c_init
+
+	led	0x1a
+	move	$lp, $r11
+	ret
+
+remap:
+	move	$r11, $lp
+#ifdef __NDS32_N1213_43U1H__	/* NDS32 V0 ISA - AG101 Only */
+	bal	2f
+relo_base:
+	move	$r0, $lp
+#else
+relo_base:
+	mfusr	$r0, $pc
+#endif /* __NDS32_N1213_43U1H__ */
+
+	/*
+	 * Remapping
+	 */
+#ifdef CONFIG_MEM_REMAP
+	/*
+	 * Copy ROM code to SDRAM base for memory remap layout.
+	 * This is not the real relocation, the real relocation is the function
+	 * relocate_code() is start.S which supports the systems is memory
+	 * remapped or not.
+	 */
+	/*
+	 * Doing memory remap is essential for preparing some non-OS or RTOS
+	 * applications.
+	 *
+	 * This is also a must on ADP-AG101 board.
+	 * The reason is because the ROM/FLASH circuit on PCB board.
+	 * AG101-A0 board has 2 jumpers MA17 and SW5 to configure which
+	 * ROM/FLASH is used to boot.
+	 *
+	 * When SW5 = "0101", MA17 = LO, the ROM is connected to BANK0,
+	 * and the FLASH is connected to BANK1.
+	 * When SW5 = "1010", MA17 = HI, the ROM is disabled (still at BANK0),
+	 * and the FLASH is connected to BANK0.
+	 * It will occur problem when doing flash probing if the flash is at
+	 * BANK0 (0x00000000) while memory remapping was skipped.
+	 *
+	 * Other board like ADP-AG101P may not enable this since there is only
+	 * a FLASH connected to bank0.
+	 */
+	led	0x21
+	li	$r4, PHYS_SDRAM_0_AT_INIT		/* 0x10000000 */
+	li	$r5, 0x0
+	la	$r1, relo_base				/* get $pc or $lp */
+	sub	$r2, $r0, $r1
+	sethi	$r6, hi20(_end)
+	ori	$r6, $r6, lo12(_end)
+	add	$r6, $r6, $r2
+1:
+	lwi.p	$r7, [$r5], #4
+	swi.p	$r7, [$r4], #4
+	blt	$r5, $r6, 1b
+
+	/* set remap bit */
+	/*
+	 * MEM remap bit is operational
+	 * - use it to map writeable memory at 0x00000000, in place of flash
+	 * - before remap: flash/rom 0x00000000, sdram: 0x10000000-0x4fffffff
+	 * - after  remap: flash/rom 0x80000000, sdram: 0x00000000
+	 */
+	led	0x2c
+	setbf15	AHBC_CR_A, FTAHBC020S_CR_REMAP		! 0x1
+
+#endif /* #ifdef CONFIG_MEM_REMAP */
+	move	$lp, $r11
+2:
+	ret
+
+.globl show_led
+show_led:
+    li      $r8, (CONFIG_DEBUG_LED)
+    swi     $r7, [$r8]
+    ret
+#endif /* #ifndef CONFIG_SKIP_LOWLEVEL_INIT */