setup-rcar-gen2.c

  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/io.h>
 12#include <linux/kernel.h>
 13#include <linux/memblock.h>
 14#include <linux/of.h>
 15#include <linux/of_clk.h>
 16#include <linux/psci.h>
 17#include <asm/mach/arch.h>
 18#include <asm/secure_cntvoff.h>
 19#include "common.h"
 20
 21static const struct of_device_id cpg_matches[] __initconst = {
 22	{ .compatible = "renesas,r8a7742-cpg-mssr", .data = "extal" },
 23	{ .compatible = "renesas,r8a7743-cpg-mssr", .data = "extal" },
 24	{ .compatible = "renesas,r8a7744-cpg-mssr", .data = "extal" },
 25	{ .compatible = "renesas,r8a7790-cpg-mssr", .data = "extal" },
 26	{ .compatible = "renesas,r8a7791-cpg-mssr", .data = "extal" },
 27	{ .compatible = "renesas,r8a7793-cpg-mssr", .data = "extal" },
 28	{ /* sentinel */ }
 29};
 30
 31static unsigned int __init get_extal_freq(void)
 32{
 33	const struct of_device_id *match;
 34	struct device_node *cpg, *extal;
 35	u32 freq = 20000000;
 36	int idx = 0;
 37
 38	cpg = of_find_matching_node_and_match(NULL, cpg_matches, &match);
 39	if (!cpg)
 40		return freq;
 41
 42	if (match->data)
 43		idx = of_property_match_string(cpg, "clock-names", match->data);
 44	extal = of_parse_phandle(cpg, "clocks", idx);
 45	of_node_put(cpg);
 46	if (!extal)
 47		return freq;
 48
 49	of_property_read_u32(extal, "clock-frequency", &freq);
 50	of_node_put(extal);
 51	return freq;
 52}
 53
 54#define CNTCR 0
 55#define CNTFID0 0x20
 56
 57static void __init rcar_gen2_timer_init(void)
 58{
 59	bool need_update = true;
 60	void __iomem *base;
 61	u32 freq;
 62
 63	/*
 64	 * If PSCI is available then most likely we are running on PSCI-enabled
 65	 * U-Boot which, we assume, has already taken care of resetting CNTVOFF
 66	 * and updating counter module before switching to non-secure mode
 67	 * and we don't need to.
 68	 */
 69#ifdef CONFIG_ARM_PSCI_FW
 70	if (psci_ops.cpu_on)
 71		need_update = false;
 72#endif
 73
 74	if (need_update == false)
 75		goto skip_update;
 76
 77	secure_cntvoff_init();
 78
 79	if (of_machine_is_compatible("renesas,r8a7745") ||
 80	    of_machine_is_compatible("renesas,r8a77470") ||
 81	    of_machine_is_compatible("renesas,r8a7792") ||
 82	    of_machine_is_compatible("renesas,r8a7794")) {
 83		freq = 260000000 / 8;	/* ZS / 8 */
 84	} else {
 85		/* At Linux boot time the r8a7790 arch timer comes up
 86		 * with the counter disabled. Moreover, it may also report
 87		 * a potentially incorrect fixed 13 MHz frequency. To be
 88		 * correct these registers need to be updated to use the
 89		 * frequency EXTAL / 2.
 90		 */
 91		freq = get_extal_freq() / 2;
 92	}
 93
 94	/* Remap "armgcnt address map" space */
 95	base = ioremap(0xe6080000, PAGE_SIZE);
 96
 97	/*
 98	 * Update the timer if it is either not running, or is not at the
 99	 * right frequency. The timer is only configurable in secure mode
100	 * so this avoids an abort if the loader started the timer and
101	 * entered the kernel in non-secure mode.
102	 */
103
104	if ((ioread32(base + CNTCR) & 1) == 0 ||
105	    ioread32(base + CNTFID0) != freq) {
106		/* Update registers with correct frequency */
107		iowrite32(freq, base + CNTFID0);
108		asm volatile("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
109
110		/* make sure arch timer is started by setting bit 0 of CNTCR */
111		iowrite32(1, base + CNTCR);
112	}
113
114	iounmap(base);
115
116skip_update:
117	of_clk_init(NULL);
118	timer_probe();
119}
120
121static const char * const rcar_gen2_boards_compat_dt[] __initconst = {
122	"renesas,r8a7790",
123	"renesas,r8a7791",
124	"renesas,r8a7792",
125	"renesas,r8a7793",
126	"renesas,r8a7794",
127	NULL
128};
129
130DT_MACHINE_START(RCAR_GEN2_DT, "Generic R-Car Gen2 (Flattened Device Tree)")
131	.init_late	= shmobile_init_late,
132	.init_time	= rcar_gen2_timer_init,
133	.dt_compat	= rcar_gen2_boards_compat_dt,
134MACHINE_END
135
136static const char * const rz_g1_boards_compat_dt[] __initconst = {
137	"renesas,r8a7742",
138	"renesas,r8a7743",
139	"renesas,r8a7744",
140	"renesas,r8a7745",
141	"renesas,r8a77470",
142	NULL
143};
144
145DT_MACHINE_START(RZ_G1_DT, "Generic RZ/G1 (Flattened Device Tree)")
146	.init_late	= shmobile_init_late,
147	.init_time	= rcar_gen2_timer_init,
148	.dt_compat	= rz_g1_boards_compat_dt,
149MACHINE_END