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