1// SPDX-License-Identifier: GPL-2.0
2/*
3 * R-Car Generation 2 support
4 *
5 * Copyright (C) 2013  Renesas Solutions Corp.
6 * Copyright (C) 2013  Magnus Damm
7 * Copyright (C) 2014  Ulrich Hecht
8 */
9
10#include <linux/clocksource.h>
11#include <linux/device.h>
12#include <linux/dma-map-ops.h>
13#include <linux/io.h>
14#include <linux/kernel.h>
15#include <linux/memblock.h>
16#include <linux/of.h>
17#include <linux/of_clk.h>
18#include <linux/of_fdt.h>
19#include <linux/of_platform.h>
20#include <linux/psci.h>
21#include <asm/mach/arch.h>
22#include <asm/secure_cntvoff.h>
23#include "common.h"
24#include "rcar-gen2.h"
25
26static const struct of_device_id cpg_matches[] __initconst = {
27	{ .compatible = "renesas,r8a7742-cpg-mssr", .data = "extal" },
28	{ .compatible = "renesas,r8a7743-cpg-mssr", .data = "extal" },
29	{ .compatible = "renesas,r8a7744-cpg-mssr", .data = "extal" },
30	{ .compatible = "renesas,r8a7790-cpg-mssr", .data = "extal" },
31	{ .compatible = "renesas,r8a7791-cpg-mssr", .data = "extal" },
32	{ .compatible = "renesas,r8a7793-cpg-mssr", .data = "extal" },
33	{ /* sentinel */ }
34};
35
36static unsigned int __init get_extal_freq(void)
37{
38	const struct of_device_id *match;
39	struct device_node *cpg, *extal;
40	u32 freq = 20000000;
41	int idx = 0;
42
43	cpg = of_find_matching_node_and_match(NULL, cpg_matches, &match);
44	if (!cpg)
45		return freq;
46
47	if (match->data)
48		idx = of_property_match_string(cpg, "clock-names", match->data);
49	extal = of_parse_phandle(cpg, "clocks", idx);
50	of_node_put(cpg);
51	if (!extal)
52		return freq;
53
54	of_property_read_u32(extal, "clock-frequency", &freq);
55	of_node_put(extal);
56	return freq;
57}
58
59#define CNTCR 0
60#define CNTFID0 0x20
61
62static void __init rcar_gen2_timer_init(void)
63{
64	bool need_update = true;
65	void __iomem *base;
66	u32 freq;
67
68	/*
69	 * If PSCI is available then most likely we are running on PSCI-enabled
70	 * U-Boot which, we assume, has already taken care of resetting CNTVOFF
71	 * and updating counter module before switching to non-secure mode
72	 * and we don't need to.
73	 */
74#ifdef CONFIG_ARM_PSCI_FW
75	if (psci_ops.cpu_on)
76		need_update = false;
77#endif
78
79	if (need_update == false)
80		goto skip_update;
81
82	secure_cntvoff_init();
83
84	if (of_machine_is_compatible("renesas,r8a7745") ||
85	    of_machine_is_compatible("renesas,r8a77470") ||
86	    of_machine_is_compatible("renesas,r8a7792") ||
87	    of_machine_is_compatible("renesas,r8a7794")) {
88		freq = 260000000 / 8;	/* ZS / 8 */
89	} else {
90		/* At Linux boot time the r8a7790 arch timer comes up
91		 * with the counter disabled. Moreover, it may also report
92		 * a potentially incorrect fixed 13 MHz frequency. To be
93		 * correct these registers need to be updated to use the
94		 * frequency EXTAL / 2.
95		 */
96		freq = get_extal_freq() / 2;
97	}
98
99	/* Remap "armgcnt address map" space */
100	base = ioremap(0xe6080000, PAGE_SIZE);
101
102	/*
103	 * Update the timer if it is either not running, or is not at the
104	 * right frequency. The timer is only configurable in secure mode
105	 * so this avoids an abort if the loader started the timer and
106	 * entered the kernel in non-secure mode.
107	 */
108
109	if ((ioread32(base + CNTCR) & 1) == 0 ||
110	    ioread32(base + CNTFID0) != freq) {
111		/* Update registers with correct frequency */
112		iowrite32(freq, base + CNTFID0);
113		asm volatile("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
114
115		/* make sure arch timer is started by setting bit 0 of CNTCR */
116		iowrite32(1, base + CNTCR);
117	}
118
119	iounmap(base);
120
121skip_update:
122	of_clk_init(NULL);
123	timer_probe();
124}
125
126struct memory_reserve_config {
127	u64 reserved;
128	u64 base, size;
129};
130
131static int __init rcar_gen2_scan_mem(unsigned long node, const char *uname,
132				     int depth, void *data)
133{
134	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
135	const __be32 *reg, *endp;
136	int l;
137	struct memory_reserve_config *mrc = data;
138	u64 lpae_start = 1ULL << 32;
139
140	/* We are scanning "memory" nodes only */
141	if (type == NULL || strcmp(type, "memory"))
142		return 0;
143
144	reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
145	if (reg == NULL)
146		reg = of_get_flat_dt_prop(node, "reg", &l);
147	if (reg == NULL)
148		return 0;
149
150	endp = reg + (l / sizeof(__be32));
151	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
152		u64 base, size;
153
154		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
155		size = dt_mem_next_cell(dt_root_size_cells, &reg);
156
157		if (base >= lpae_start)
158			continue;
159
160		if ((base + size) >= lpae_start)
161			size = lpae_start - base;
162
163		if (size < mrc->reserved)
164			continue;
165
166		if (base < mrc->base)
167			continue;
168
169		/* keep the area at top near the 32-bit legacy limit */
170		mrc->base = base + size - mrc->reserved;
171		mrc->size = mrc->reserved;
172	}
173
174	return 0;
175}
176
177static void __init rcar_gen2_reserve(void)
178{
179	struct memory_reserve_config mrc;
180
181	/* reserve 256 MiB at the top of the physical legacy 32-bit space */
182	memset(&mrc, 0, sizeof(mrc));
183	mrc.reserved = SZ_256M;
184
185	of_scan_flat_dt(rcar_gen2_scan_mem, &mrc);
186#ifdef CONFIG_DMA_CMA
187	if (mrc.size && memblock_is_region_memory(mrc.base, mrc.size)) {
188		static struct cma *rcar_gen2_dma_contiguous;
189
190		dma_contiguous_reserve_area(mrc.size, mrc.base, 0,
191					    &rcar_gen2_dma_contiguous, true);
192	}
193#endif
194}
195
196static const char * const rcar_gen2_boards_compat_dt[] __initconst = {
197	"renesas,r8a7790",
198	"renesas,r8a7791",
199	"renesas,r8a7792",
200	"renesas,r8a7793",
201	"renesas,r8a7794",
202	NULL,
203};
204
205DT_MACHINE_START(RCAR_GEN2_DT, "Generic R-Car Gen2 (Flattened Device Tree)")
206	.init_late	= shmobile_init_late,
207	.init_time	= rcar_gen2_timer_init,
208	.reserve	= rcar_gen2_reserve,
209	.dt_compat	= rcar_gen2_boards_compat_dt,
210MACHINE_END
211
212static const char * const rz_g1_boards_compat_dt[] __initconst = {
213	"renesas,r8a7742",
214	"renesas,r8a7743",
215	"renesas,r8a7744",
216	"renesas,r8a7745",
217	"renesas,r8a77470",
218	NULL,
219};
220
221DT_MACHINE_START(RZ_G1_DT, "Generic RZ/G1 (Flattened Device Tree)")
222	.init_late	= shmobile_init_late,
223	.init_time	= rcar_gen2_timer_init,
224	.reserve	= rcar_gen2_reserve,
225	.dt_compat	= rz_g1_boards_compat_dt,
226MACHINE_END
227