xref: /openbmc/linux/arch/arm/mach-exynos/firmware.c (revision d5e7cafd)
1 /*
2  * Copyright (C) 2012 Samsung Electronics.
3  * Kyungmin Park <kyungmin.park@samsung.com>
4  * Tomasz Figa <t.figa@samsung.com>
5  *
6  * This program is free software,you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/io.h>
13 #include <linux/init.h>
14 #include <linux/of.h>
15 #include <linux/of_address.h>
16 
17 #include <asm/cacheflush.h>
18 #include <asm/cputype.h>
19 #include <asm/firmware.h>
20 #include <asm/hardware/cache-l2x0.h>
21 #include <asm/suspend.h>
22 
23 #include <mach/map.h>
24 
25 #include "common.h"
26 #include "smc.h"
27 
28 #define EXYNOS_SLEEP_MAGIC	0x00000bad
29 #define EXYNOS_AFTR_MAGIC	0xfcba0d10
30 #define EXYNOS_BOOT_ADDR	0x8
31 #define EXYNOS_BOOT_FLAG	0xc
32 
33 static void exynos_save_cp15(void)
34 {
35 	/* Save Power control and Diagnostic registers */
36 	asm ("mrc p15, 0, %0, c15, c0, 0\n"
37 	     "mrc p15, 0, %1, c15, c0, 1\n"
38 	     : "=r" (cp15_save_power), "=r" (cp15_save_diag)
39 	     : : "cc");
40 }
41 
42 static int exynos_do_idle(unsigned long mode)
43 {
44 	switch (mode) {
45 	case FW_DO_IDLE_AFTR:
46 		if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
47 			exynos_save_cp15();
48 		__raw_writel(virt_to_phys(exynos_cpu_resume_ns),
49 			     sysram_ns_base_addr + 0x24);
50 		__raw_writel(EXYNOS_AFTR_MAGIC, sysram_ns_base_addr + 0x20);
51 		exynos_smc(SMC_CMD_CPU0AFTR, 0, 0, 0);
52 		break;
53 	case FW_DO_IDLE_SLEEP:
54 		exynos_smc(SMC_CMD_SLEEP, 0, 0, 0);
55 	}
56 	return 0;
57 }
58 
59 static int exynos_cpu_boot(int cpu)
60 {
61 	/*
62 	 * Exynos3250 doesn't need to send smc command for secondary CPU boot
63 	 * because Exynos3250 removes WFE in secure mode.
64 	 */
65 	if (soc_is_exynos3250())
66 		return 0;
67 
68 	/*
69 	 * The second parameter of SMC_CMD_CPU1BOOT command means CPU id.
70 	 * But, Exynos4212 has only one secondary CPU so second parameter
71 	 * isn't used for informing secure firmware about CPU id.
72 	 */
73 	if (soc_is_exynos4212())
74 		cpu = 0;
75 
76 	exynos_smc(SMC_CMD_CPU1BOOT, cpu, 0, 0);
77 	return 0;
78 }
79 
80 static int exynos_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
81 {
82 	void __iomem *boot_reg;
83 
84 	if (!sysram_ns_base_addr)
85 		return -ENODEV;
86 
87 	boot_reg = sysram_ns_base_addr + 0x1c;
88 
89 	/*
90 	 * Almost all Exynos-series of SoCs that run in secure mode don't need
91 	 * additional offset for every CPU, with Exynos4412 being the only
92 	 * exception.
93 	 */
94 	if (soc_is_exynos4412())
95 		boot_reg += 4 * cpu;
96 
97 	__raw_writel(boot_addr, boot_reg);
98 	return 0;
99 }
100 
101 static int exynos_cpu_suspend(unsigned long arg)
102 {
103 	flush_cache_all();
104 	outer_flush_all();
105 
106 	exynos_smc(SMC_CMD_SLEEP, 0, 0, 0);
107 
108 	pr_info("Failed to suspend the system\n");
109 	writel(0, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
110 	return 1;
111 }
112 
113 static int exynos_suspend(void)
114 {
115 	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
116 		exynos_save_cp15();
117 
118 	writel(EXYNOS_SLEEP_MAGIC, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
119 	writel(virt_to_phys(exynos_cpu_resume_ns),
120 		sysram_ns_base_addr + EXYNOS_BOOT_ADDR);
121 
122 	return cpu_suspend(0, exynos_cpu_suspend);
123 }
124 
125 static int exynos_resume(void)
126 {
127 	writel(0, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
128 
129 	return 0;
130 }
131 
132 static const struct firmware_ops exynos_firmware_ops = {
133 	.do_idle		= IS_ENABLED(CONFIG_EXYNOS_CPU_SUSPEND) ? exynos_do_idle : NULL,
134 	.set_cpu_boot_addr	= exynos_set_cpu_boot_addr,
135 	.cpu_boot		= exynos_cpu_boot,
136 	.suspend		= IS_ENABLED(CONFIG_PM_SLEEP) ? exynos_suspend : NULL,
137 	.resume			= IS_ENABLED(CONFIG_EXYNOS_CPU_SUSPEND) ? exynos_resume : NULL,
138 };
139 
140 static void exynos_l2_write_sec(unsigned long val, unsigned reg)
141 {
142 	static int l2cache_enabled;
143 
144 	switch (reg) {
145 	case L2X0_CTRL:
146 		if (val & L2X0_CTRL_EN) {
147 			/*
148 			 * Before the cache can be enabled, due to firmware
149 			 * design, SMC_CMD_L2X0INVALL must be called.
150 			 */
151 			if (!l2cache_enabled) {
152 				exynos_smc(SMC_CMD_L2X0INVALL, 0, 0, 0);
153 				l2cache_enabled = 1;
154 			}
155 		} else {
156 			l2cache_enabled = 0;
157 		}
158 		exynos_smc(SMC_CMD_L2X0CTRL, val, 0, 0);
159 		break;
160 
161 	case L2X0_DEBUG_CTRL:
162 		exynos_smc(SMC_CMD_L2X0DEBUG, val, 0, 0);
163 		break;
164 
165 	default:
166 		WARN_ONCE(1, "%s: ignoring write to reg 0x%x\n", __func__, reg);
167 	}
168 }
169 
170 static void exynos_l2_configure(const struct l2x0_regs *regs)
171 {
172 	exynos_smc(SMC_CMD_L2X0SETUP1, regs->tag_latency, regs->data_latency,
173 		   regs->prefetch_ctrl);
174 	exynos_smc(SMC_CMD_L2X0SETUP2, regs->pwr_ctrl, regs->aux_ctrl, 0);
175 }
176 
177 void __init exynos_firmware_init(void)
178 {
179 	struct device_node *nd;
180 	const __be32 *addr;
181 
182 	nd = of_find_compatible_node(NULL, NULL,
183 					"samsung,secure-firmware");
184 	if (!nd)
185 		return;
186 
187 	addr = of_get_address(nd, 0, NULL, NULL);
188 	if (!addr) {
189 		pr_err("%s: No address specified.\n", __func__);
190 		return;
191 	}
192 
193 	pr_info("Running under secure firmware.\n");
194 
195 	register_firmware_ops(&exynos_firmware_ops);
196 
197 	/*
198 	 * Exynos 4 SoCs (based on Cortex A9 and equipped with L2C-310),
199 	 * running under secure firmware, require certain registers of L2
200 	 * cache controller to be written in secure mode. Here .write_sec
201 	 * callback is provided to perform necessary SMC calls.
202 	 */
203 	if (IS_ENABLED(CONFIG_CACHE_L2X0) &&
204 	    read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
205 		outer_cache.write_sec = exynos_l2_write_sec;
206 		outer_cache.configure = exynos_l2_configure;
207 	}
208 }
209