summaryrefslogtreecommitdiffstats
path: root/arch/arc/plat-hsdk/platform.c
blob: 2588b842407c281df0051b814fefd3cfcd9c31fe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
/*
 * ARC HSDK Platform support code
 *
 * Copyright (C) 2017 Synopsys, Inc. (www.synopsys.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/smp.h>
#include <asm/arcregs.h>
#include <asm/io.h>
#include <asm/mach_desc.h>

#define ARC_CCM_UNUSED_ADDR	0x60000000

static void __init hsdk_init_per_cpu(unsigned int cpu)
{
	/*
	 * By default ICCM is mapped to 0x7z while this area is used for
	 * kernel virtual mappings, so move it to currently unused area.
	 */
	if (cpuinfo_arc700[cpu].iccm.sz)
		write_aux_reg(ARC_REG_AUX_ICCM, ARC_CCM_UNUSED_ADDR);

	/*
	 * By default DCCM is mapped to 0x8z while this area is used by kernel,
	 * so move it to currently unused area.
	 */
	if (cpuinfo_arc700[cpu].dccm.sz)
		write_aux_reg(ARC_REG_AUX_DCCM, ARC_CCM_UNUSED_ADDR);
}

#define ARC_PERIPHERAL_BASE	0xf0000000
#define CREG_BASE		(ARC_PERIPHERAL_BASE + 0x1000)
#define CREG_PAE		(CREG_BASE + 0x180)
#define CREG_PAE_UPDATE		(CREG_BASE + 0x194)

#define SDIO_BASE		(ARC_PERIPHERAL_BASE + 0xA000)
#define SDIO_UHS_REG_EXT	(SDIO_BASE + 0x108)
#define SDIO_UHS_REG_EXT_DIV_2	(2 << 30)

#define HSDK_GPIO_INTC          (ARC_PERIPHERAL_BASE + 0x3000)

static void __init hsdk_enable_gpio_intc_wire(void)
{
	/*
	 * Peripherals on CPU Card are wired to cpu intc via intermediate
	 * DW APB GPIO blocks (mainly for debouncing)
	 *
	 *         ---------------------
	 *        |  snps,archs-intc  |
	 *        ---------------------
	 *                  |
	 *        ----------------------
	 *        | snps,archs-idu-intc |
	 *        ----------------------
	 *         |   |     |   |    |
	 *         | [eth] [USB]    [... other peripherals]
	 *         |
	 * -------------------
	 * | snps,dw-apb-intc |
	 * -------------------
	 *  |      |   |   |
	 * [Bt] [HAPS]   [... other peripherals]
	 *
	 * Current implementation of "irq-dw-apb-ictl" driver doesn't work well
	 * with stacked INTCs. In particular problem happens if its master INTC
	 * not yet instantiated. See discussion here -
	 * https://lkml.org/lkml/2015/3/4/755
	 *
	 * So setup the first gpio block as a passive pass thru and hide it from
	 * DT hardware topology - connect intc directly to cpu intc
	 * The GPIO "wire" needs to be init nevertheless (here)
	 *
	 * One side adv is that peripheral interrupt handling avoids one nested
	 * intc ISR hop
	 *
	 * According to HSDK User's Manual [1], "Table 2 Interrupt Mapping"
	 * we have the following GPIO input lines used as sources of interrupt:
	 * - GPIO[0] - Bluetooth interrupt of RS9113 module
	 * - GPIO[2] - HAPS interrupt (on HapsTrak 3 connector)
	 * - GPIO[3] - Audio codec (MAX9880A) interrupt
	 * - GPIO[8-23] - Available on Arduino and PMOD_x headers
	 * For now there's no use of Arduino and PMOD_x headers in Linux
	 * use-case so we only enable lines 0, 2 and 3.
	 *
	 * [1] https://github.com/foss-for-synopsys-dwc-arc-processors/ARC-Development-Systems-Forum/wiki/docs/ARC_HSDK_User_Guide.pdf
	 */
#define GPIO_INTEN              (HSDK_GPIO_INTC + 0x30)
#define GPIO_INTMASK            (HSDK_GPIO_INTC + 0x34)
#define GPIO_INTTYPE_LEVEL      (HSDK_GPIO_INTC + 0x38)
#define GPIO_INT_POLARITY       (HSDK_GPIO_INTC + 0x3c)
#define GPIO_INT_CONNECTED_MASK	0x0d

	iowrite32(0xffffffff, (void __iomem *) GPIO_INTMASK);
	iowrite32(~GPIO_INT_CONNECTED_MASK, (void __iomem *) GPIO_INTMASK);
	iowrite32(0x00000000, (void __iomem *) GPIO_INTTYPE_LEVEL);
	iowrite32(0xffffffff, (void __iomem *) GPIO_INT_POLARITY);
	iowrite32(GPIO_INT_CONNECTED_MASK, (void __iomem *) GPIO_INTEN);
}

static void __init hsdk_init_early(void)
{
	/*
	 * PAE remapping for DMA clients does not work due to an RTL bug, so
	 * CREG_PAE register must be programmed to all zeroes, otherwise it
	 * will cause problems with DMA to/from peripherals even if PAE40 is
	 * not used.
	 */

	/* Default is 1, which means "PAE offset = 4GByte" */
	writel_relaxed(0, (void __iomem *) CREG_PAE);

	/* Really apply settings made above */
	writel(1, (void __iomem *) CREG_PAE_UPDATE);

	/*
	 * Switch SDIO external ciu clock divider from default div-by-8 to
	 * minimum possible div-by-2.
	 */
	iowrite32(SDIO_UHS_REG_EXT_DIV_2, (void __iomem *) SDIO_UHS_REG_EXT);

	hsdk_enable_gpio_intc_wire();
}

static const char *hsdk_compat[] __initconst = {
	"snps,hsdk",
	NULL,
};

MACHINE_START(SIMULATION, "hsdk")
	.dt_compat	= hsdk_compat,
	.init_early     = hsdk_init_early,
	.init_per_cpu	= hsdk_init_per_cpu,
MACHINE_END