xref: /openbmc/u-boot/arch/x86/cpu/quark/car.S (revision 1d2c0506)
1/*
2 * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
3 *
4 * SPDX-License-Identifier:	GPL-2.0+
5 */
6
7#include <config.h>
8#include <asm/pci.h>
9#include <asm/post.h>
10#include <asm/arch/quark.h>
11#include <asm/arch/msg_port.h>
12
13.globl car_init
14car_init:
15	post_code(POST_CAR_START)
16
17	/*
18	 * Quark SoC contains an embedded 512KiB SRAM (eSRAM) that is
19	 * initialized by hardware. eSRAM is the ideal place to be used
20	 * for Cache-As-RAM (CAR) before system memory is available.
21	 *
22	 * Relocate this eSRAM to a suitable location in the physical
23	 * memory map and enable it.
24	 */
25
26	/* Host Memory Bound Register P03h:R08h */
27	mov	$((MSG_PORT_HOST_BRIDGE << 16) | (HM_BOUND << 8)), %eax
28	mov	$(DRAM_BASE + DRAM_MAX_SIZE + ESRAM_SIZE), %edx
29	lea	1f, %esp
30	jmp	msg_port_write
311:
32
33	/* eSRAM Block Page Control Register P05h:R82h */
34	mov	$((MSG_PORT_MEM_MGR << 16) | (ESRAM_BLK_CTRL << 8)), %eax
35	mov	$(ESRAM_BLOCK_MODE | (CONFIG_ESRAM_BASE >> 24)), %edx
36	lea	2f, %esp
37	jmp	msg_port_write
382:
39
40	post_code(POST_CAR_CPU_CACHE)
41	jmp	car_init_ret
42
43msg_port_read:
44	/*
45	 * Parameter:
46	 *   eax[23:16] - Message Port ID
47	 *   eax[15:08] - Register Address
48	 *
49	 * Return Value:
50	 *   eax - Message Port Register value
51	 *
52	 * Return Address: esp
53	 */
54
55	or	$((MSG_OP_READ << 24) | MSG_BYTE_ENABLE), %eax
56	mov	%eax, %ebx
57
58	/* Write MCR B0:D0:F0:RD0 */
59	mov	$(PCI_CFG_EN | MSG_CTRL_REG), %eax
60	mov	$PCI_REG_ADDR, %dx
61	out	%eax, %dx
62	mov	$PCI_REG_DATA, %dx
63	mov	%ebx, %eax
64	out	%eax, %dx
65
66	/* Read MDR B0:D0:F0:RD4 */
67	mov	$(PCI_CFG_EN | MSG_DATA_REG), %eax
68	mov	$PCI_REG_ADDR, %dx
69	out	%eax, %dx
70	mov	$PCI_REG_DATA, %dx
71	in	%dx, %eax
72
73	jmp	*%esp
74
75msg_port_write:
76	/*
77	 * Parameter:
78	 *   eax[23:16] - Message Port ID
79	 *   eax[15:08] - Register Address
80	 *   edx        - Message Port Register value to write
81	 *
82	 * Return Address: esp
83	 */
84
85	or	$((MSG_OP_WRITE << 24) | MSG_BYTE_ENABLE), %eax
86	mov	%eax, %esi
87	mov	%edx, %edi
88
89	/* Write MDR B0:D0:F0:RD4 */
90	mov	$(PCI_CFG_EN | MSG_DATA_REG), %eax
91	mov	$PCI_REG_ADDR, %dx
92	out	%eax, %dx
93	mov	$PCI_REG_DATA, %dx
94	mov	%edi, %eax
95	out	%eax, %dx
96
97	/* Write MCR B0:D0:F0:RD0 */
98	mov	$(PCI_CFG_EN | MSG_CTRL_REG), %eax
99	mov	$PCI_REG_ADDR, %dx
100	out	%eax, %dx
101	mov	$PCI_REG_DATA, %dx
102	mov	%esi, %eax
103	out	%eax, %dx
104
105	jmp	*%esp
106