xref: /openbmc/linux/arch/arm/mach-exynos/firmware.c (revision ae0be8de)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (C) 2012 Samsung Electronics.
4 // Kyungmin Park <kyungmin.park@samsung.com>
5 // Tomasz Figa <t.figa@samsung.com>
6 
7 #include <linux/kernel.h>
8 #include <linux/io.h>
9 #include <linux/init.h>
10 #include <linux/of.h>
11 #include <linux/of_address.h>
12 
13 #include <asm/cacheflush.h>
14 #include <asm/cputype.h>
15 #include <asm/firmware.h>
16 #include <asm/hardware/cache-l2x0.h>
17 #include <asm/suspend.h>
18 
19 #include "common.h"
20 #include "smc.h"
21 
22 #define EXYNOS_BOOT_ADDR	0x8
23 #define EXYNOS_BOOT_FLAG	0xc
24 
25 static void exynos_save_cp15(void)
26 {
27 	/* Save Power control and Diagnostic registers */
28 	asm ("mrc p15, 0, %0, c15, c0, 0\n"
29 	     "mrc p15, 0, %1, c15, c0, 1\n"
30 	     : "=r" (cp15_save_power), "=r" (cp15_save_diag)
31 	     : : "cc");
32 }
33 
34 static int exynos_do_idle(unsigned long mode)
35 {
36 	switch (mode) {
37 	case FW_DO_IDLE_AFTR:
38 		if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
39 			exynos_save_cp15();
40 		writel_relaxed(__pa_symbol(exynos_cpu_resume_ns),
41 			       sysram_ns_base_addr + 0x24);
42 		writel_relaxed(EXYNOS_AFTR_MAGIC, sysram_ns_base_addr + 0x20);
43 		if (soc_is_exynos3250()) {
44 			flush_cache_all();
45 			exynos_smc(SMC_CMD_SAVE, OP_TYPE_CORE,
46 				   SMC_POWERSTATE_IDLE, 0);
47 			exynos_smc(SMC_CMD_SHUTDOWN, OP_TYPE_CLUSTER,
48 				   SMC_POWERSTATE_IDLE, 0);
49 		} else
50 			exynos_smc(SMC_CMD_CPU0AFTR, 0, 0, 0);
51 		break;
52 	case FW_DO_IDLE_SLEEP:
53 		exynos_smc(SMC_CMD_SLEEP, 0, 0, 0);
54 	}
55 	return 0;
56 }
57 
58 static int exynos_cpu_boot(int cpu)
59 {
60 	/*
61 	 * Exynos3250 doesn't need to send smc command for secondary CPU boot
62 	 * because Exynos3250 removes WFE in secure mode.
63 	 */
64 	if (soc_is_exynos3250())
65 		return 0;
66 
67 	/*
68 	 * The second parameter of SMC_CMD_CPU1BOOT command means CPU id.
69 	 */
70 	exynos_smc(SMC_CMD_CPU1BOOT, cpu, 0, 0);
71 	return 0;
72 }
73 
74 static int exynos_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
75 {
76 	void __iomem *boot_reg;
77 
78 	if (!sysram_ns_base_addr)
79 		return -ENODEV;
80 
81 	boot_reg = sysram_ns_base_addr + 0x1c;
82 
83 	/*
84 	 * Almost all Exynos-series of SoCs that run in secure mode don't need
85 	 * additional offset for every CPU, with Exynos4412 being the only
86 	 * exception.
87 	 */
88 	if (soc_is_exynos4412())
89 		boot_reg += 4 * cpu;
90 
91 	writel_relaxed(boot_addr, boot_reg);
92 	return 0;
93 }
94 
95 static int exynos_get_cpu_boot_addr(int cpu, unsigned long *boot_addr)
96 {
97 	void __iomem *boot_reg;
98 
99 	if (!sysram_ns_base_addr)
100 		return -ENODEV;
101 
102 	boot_reg = sysram_ns_base_addr + 0x1c;
103 
104 	if (soc_is_exynos4412())
105 		boot_reg += 4 * cpu;
106 
107 	*boot_addr = readl_relaxed(boot_reg);
108 	return 0;
109 }
110 
111 static int exynos_cpu_suspend(unsigned long arg)
112 {
113 	flush_cache_all();
114 	outer_flush_all();
115 
116 	exynos_smc(SMC_CMD_SLEEP, 0, 0, 0);
117 
118 	pr_info("Failed to suspend the system\n");
119 	writel(0, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
120 	return 1;
121 }
122 
123 static int exynos_suspend(void)
124 {
125 	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
126 		exynos_save_cp15();
127 
128 	writel(EXYNOS_SLEEP_MAGIC, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
129 	writel(__pa_symbol(exynos_cpu_resume_ns),
130 		sysram_ns_base_addr + EXYNOS_BOOT_ADDR);
131 
132 	return cpu_suspend(0, exynos_cpu_suspend);
133 }
134 
135 static int exynos_resume(void)
136 {
137 	writel(0, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
138 
139 	return 0;
140 }
141 
142 static const struct firmware_ops exynos_firmware_ops = {
143 	.do_idle		= IS_ENABLED(CONFIG_EXYNOS_CPU_SUSPEND) ? exynos_do_idle : NULL,
144 	.set_cpu_boot_addr	= exynos_set_cpu_boot_addr,
145 	.get_cpu_boot_addr	= exynos_get_cpu_boot_addr,
146 	.cpu_boot		= exynos_cpu_boot,
147 	.suspend		= IS_ENABLED(CONFIG_PM_SLEEP) ? exynos_suspend : NULL,
148 	.resume			= IS_ENABLED(CONFIG_EXYNOS_CPU_SUSPEND) ? exynos_resume : NULL,
149 };
150 
151 static void exynos_l2_write_sec(unsigned long val, unsigned reg)
152 {
153 	static int l2cache_enabled;
154 
155 	switch (reg) {
156 	case L2X0_CTRL:
157 		if (val & L2X0_CTRL_EN) {
158 			/*
159 			 * Before the cache can be enabled, due to firmware
160 			 * design, SMC_CMD_L2X0INVALL must be called.
161 			 */
162 			if (!l2cache_enabled) {
163 				exynos_smc(SMC_CMD_L2X0INVALL, 0, 0, 0);
164 				l2cache_enabled = 1;
165 			}
166 		} else {
167 			l2cache_enabled = 0;
168 		}
169 		exynos_smc(SMC_CMD_L2X0CTRL, val, 0, 0);
170 		break;
171 
172 	case L2X0_DEBUG_CTRL:
173 		exynos_smc(SMC_CMD_L2X0DEBUG, val, 0, 0);
174 		break;
175 
176 	default:
177 		WARN_ONCE(1, "%s: ignoring write to reg 0x%x\n", __func__, reg);
178 	}
179 }
180 
181 static void exynos_l2_configure(const struct l2x0_regs *regs)
182 {
183 	exynos_smc(SMC_CMD_L2X0SETUP1, regs->tag_latency, regs->data_latency,
184 		   regs->prefetch_ctrl);
185 	exynos_smc(SMC_CMD_L2X0SETUP2, regs->pwr_ctrl, regs->aux_ctrl, 0);
186 }
187 
188 bool __init exynos_secure_firmware_available(void)
189 {
190 	struct device_node *nd;
191 	const __be32 *addr;
192 
193 	nd = of_find_compatible_node(NULL, NULL,
194 					"samsung,secure-firmware");
195 	if (!nd)
196 		return false;
197 
198 	addr = of_get_address(nd, 0, NULL, NULL);
199 	if (!addr) {
200 		pr_err("%s: No address specified.\n", __func__);
201 		return false;
202 	}
203 
204 	return true;
205 }
206 
207 void __init exynos_firmware_init(void)
208 {
209 	if (!exynos_secure_firmware_available())
210 		return;
211 
212 	pr_info("Running under secure firmware.\n");
213 
214 	register_firmware_ops(&exynos_firmware_ops);
215 
216 	/*
217 	 * Exynos 4 SoCs (based on Cortex A9 and equipped with L2C-310),
218 	 * running under secure firmware, require certain registers of L2
219 	 * cache controller to be written in secure mode. Here .write_sec
220 	 * callback is provided to perform necessary SMC calls.
221 	 */
222 	if (IS_ENABLED(CONFIG_CACHE_L2X0) &&
223 	    read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
224 		outer_cache.write_sec = exynos_l2_write_sec;
225 		outer_cache.configure = exynos_l2_configure;
226 	}
227 }
228 
229 #define REG_CPU_STATE_ADDR	(sysram_ns_base_addr + 0x28)
230 #define BOOT_MODE_MASK		0x1f
231 
232 void exynos_set_boot_flag(unsigned int cpu, unsigned int mode)
233 {
234 	unsigned int tmp;
235 
236 	tmp = readl_relaxed(REG_CPU_STATE_ADDR + cpu * 4);
237 
238 	if (mode & BOOT_MODE_MASK)
239 		tmp &= ~BOOT_MODE_MASK;
240 
241 	tmp |= mode;
242 	writel_relaxed(tmp, REG_CPU_STATE_ADDR + cpu * 4);
243 }
244 
245 void exynos_clear_boot_flag(unsigned int cpu, unsigned int mode)
246 {
247 	unsigned int tmp;
248 
249 	tmp = readl_relaxed(REG_CPU_STATE_ADDR + cpu * 4);
250 	tmp &= ~mode;
251 	writel_relaxed(tmp, REG_CPU_STATE_ADDR + cpu * 4);
252 }
253