xref: /openbmc/u-boot/arch/mips/mach-mscc/cpu.c (revision 224f7452)
1 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
2 /*
3  * Copyright (c) 2018 Microsemi Corporation
4  */
5 
6 #include <common.h>
7 
8 #include <asm/io.h>
9 #include <asm/types.h>
10 
11 #include <mach/tlb.h>
12 #include <mach/ddr.h>
13 
14 DECLARE_GLOBAL_DATA_PTR;
15 
16 #if CONFIG_SYS_SDRAM_SIZE <= SZ_64M
17 #define MSCC_RAM_TLB_SIZE   SZ_64M
18 #define MSCC_ATTRIB2   MMU_REGIO_INVAL
19 #elif CONFIG_SYS_SDRAM_SIZE <= SZ_128M
20 #define MSCC_RAM_TLB_SIZE   SZ_64M
21 #define MSCC_ATTRIB2   MMU_REGIO_RW
22 #elif CONFIG_SYS_SDRAM_SIZE <= SZ_256M
23 #define MSCC_RAM_TLB_SIZE   SZ_256M
24 #define MSCC_ATTRIB2   MMU_REGIO_INVAL
25 #elif CONFIG_SYS_SDRAM_SIZE <= SZ_512M
26 #define MSCC_RAM_TLB_SIZE   SZ_256M
27 #define MSCC_ATTRIB2   MMU_REGIO_RW
28 #else
29 #define MSCC_RAM_TLB_SIZE   SZ_512M
30 #define MSCC_ATTRIB2   MMU_REGIO_RW
31 #endif
32 
33 /* NOTE: lowlevel_init() function does not have access to the
34  * stack. Thus, all called functions must be inlined, and (any) local
35  * variables must be kept in registers.
36  */
37 void vcoreiii_tlb_init(void)
38 {
39 	register int tlbix = 0;
40 
41 	/*
42 	 * Unlike most of the MIPS based SoCs, the IO register address
43 	 * are not in KSEG0. The mainline linux kernel built in legacy
44 	 * mode needs to access some of the registers very early in
45 	 * the boot and make the assumption that the bootloader has
46 	 * already configured them, so we have to match this
47 	 * expectation.
48 	 */
49 	create_tlb(tlbix++, MSCC_IO_ORIGIN1_OFFSET, SZ_16M, MMU_REGIO_RW,
50 		   MMU_REGIO_RW);
51 #ifdef CONFIG_SOC_LUTON
52 	create_tlb(tlbix++, MSCC_IO_ORIGIN2_OFFSET, SZ_16M, MMU_REGIO_RW,
53 		   MMU_REGIO_RW);
54 #endif
55 
56 #if  CONFIG_SYS_TEXT_BASE == MSCC_FLASH_TO
57 	/*
58 	 * If U-Boot is located in NOR then we want to be able to use
59 	 * the data cache in order to boot in a decent duration
60 	 */
61 	create_tlb(tlbix++, MSCC_FLASH_TO, SZ_16M, MMU_REGIO_RO_C,
62 		   MMU_REGIO_RO_C);
63 	create_tlb(tlbix++, MSCC_FLASH_TO + SZ_32M, SZ_16M, MMU_REGIO_RO_C,
64 		   MMU_REGIO_RO_C);
65 
66 	/*
67 	 * Using cache for RAM also helps to improve boot time. Thanks
68 	 * to this the time to relocate U-Boot in RAM went from 2.092
69 	 * secs to 0.104 secs.
70 	 */
71 	create_tlb(tlbix++, MSCC_DDR_TO, MSCC_RAM_TLB_SIZE, MMU_REGIO_RW,
72 		   MSCC_ATTRIB2);
73 
74 	/* Enable caches by clearing the bit ERL, which is set on reset */
75 	write_c0_status(read_c0_status() & ~BIT(2));
76 #endif /* CONFIG_SYS_TEXT_BASE */
77 }
78 
79 int mach_cpu_init(void)
80 {
81 	/* Speed up NOR flash access */
82 #ifdef CONFIG_SOC_LUTON
83 	writel(ICPU_PI_MST_CFG_TRISTATE_CTRL +
84 	       ICPU_PI_MST_CFG_CLK_DIV(4), BASE_CFG + ICPU_PI_MST_CFG);
85 
86 	writel(ICPU_SPI_MST_CFG_FAST_READ_ENA +
87 	       ICPU_SPI_MST_CFG_CS_DESELECT_TIME(0x19) +
88 	       ICPU_SPI_MST_CFG_CLK_DIV(9), BASE_CFG + ICPU_SPI_MST_CFG);
89 #else
90 	writel(ICPU_SPI_MST_CFG_CS_DESELECT_TIME(0x19) +
91 	       ICPU_SPI_MST_CFG_CLK_DIV(9), BASE_CFG + ICPU_SPI_MST_CFG);
92 	/*
93 	 * Legacy and mainline linux kernel expect that the
94 	 * interruption map was set as it was done by redboot.
95 	 */
96 	writel(~0, BASE_CFG + ICPU_DST_INTR_MAP(0));
97 	writel(0, BASE_CFG + ICPU_DST_INTR_MAP(1));
98 	writel(0, BASE_CFG + ICPU_DST_INTR_MAP(2));
99 	writel(0, BASE_CFG + ICPU_DST_INTR_MAP(3));
100 #endif
101 	return 0;
102 }
103