xref: /openbmc/linux/arch/arm/mach-exynos/firmware.c (revision 0c6dfa75)
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 	 * On Exynos5 devices the call is ignored by trustzone firmware.
65 	 */
66 	if (!soc_is_exynos4210() && !soc_is_exynos4212() &&
67 	    !soc_is_exynos4412())
68 		return 0;
69 
70 	/*
71 	 * The second parameter of SMC_CMD_CPU1BOOT command means CPU id.
72 	 * But, Exynos4212 has only one secondary CPU so second parameter
73 	 * isn't used for informing secure firmware about CPU id.
74 	 */
75 	if (soc_is_exynos4212())
76 		cpu = 0;
77 
78 	exynos_smc(SMC_CMD_CPU1BOOT, cpu, 0, 0);
79 	return 0;
80 }
81 
82 static int exynos_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
83 {
84 	void __iomem *boot_reg;
85 
86 	if (!sysram_ns_base_addr)
87 		return -ENODEV;
88 
89 	boot_reg = sysram_ns_base_addr + 0x1c;
90 
91 	/*
92 	 * Almost all Exynos-series of SoCs that run in secure mode don't need
93 	 * additional offset for every CPU, with Exynos4412 being the only
94 	 * exception.
95 	 */
96 	if (soc_is_exynos4412())
97 		boot_reg += 4 * cpu;
98 
99 	writel_relaxed(boot_addr, boot_reg);
100 	return 0;
101 }
102 
103 static int exynos_get_cpu_boot_addr(int cpu, unsigned long *boot_addr)
104 {
105 	void __iomem *boot_reg;
106 
107 	if (!sysram_ns_base_addr)
108 		return -ENODEV;
109 
110 	boot_reg = sysram_ns_base_addr + 0x1c;
111 
112 	if (soc_is_exynos4412())
113 		boot_reg += 4 * cpu;
114 
115 	*boot_addr = readl_relaxed(boot_reg);
116 	return 0;
117 }
118 
119 static int exynos_cpu_suspend(unsigned long arg)
120 {
121 	flush_cache_all();
122 	outer_flush_all();
123 
124 	exynos_smc(SMC_CMD_SLEEP, 0, 0, 0);
125 
126 	pr_info("Failed to suspend the system\n");
127 	writel(0, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
128 	return 1;
129 }
130 
131 static int exynos_suspend(void)
132 {
133 	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
134 		exynos_save_cp15();
135 
136 	writel(EXYNOS_SLEEP_MAGIC, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
137 	writel(__pa_symbol(exynos_cpu_resume_ns),
138 		sysram_ns_base_addr + EXYNOS_BOOT_ADDR);
139 
140 	return cpu_suspend(0, exynos_cpu_suspend);
141 }
142 
143 static int exynos_resume(void)
144 {
145 	writel(0, sysram_ns_base_addr + EXYNOS_BOOT_FLAG);
146 
147 	return 0;
148 }
149 
150 static const struct firmware_ops exynos_firmware_ops = {
151 	.do_idle		= IS_ENABLED(CONFIG_EXYNOS_CPU_SUSPEND) ? exynos_do_idle : NULL,
152 	.set_cpu_boot_addr	= exynos_set_cpu_boot_addr,
153 	.get_cpu_boot_addr	= exynos_get_cpu_boot_addr,
154 	.cpu_boot		= exynos_cpu_boot,
155 	.suspend		= IS_ENABLED(CONFIG_PM_SLEEP) ? exynos_suspend : NULL,
156 	.resume			= IS_ENABLED(CONFIG_EXYNOS_CPU_SUSPEND) ? exynos_resume : NULL,
157 };
158 
159 static void exynos_l2_write_sec(unsigned long val, unsigned reg)
160 {
161 	static int l2cache_enabled;
162 
163 	switch (reg) {
164 	case L2X0_CTRL:
165 		if (val & L2X0_CTRL_EN) {
166 			/*
167 			 * Before the cache can be enabled, due to firmware
168 			 * design, SMC_CMD_L2X0INVALL must be called.
169 			 */
170 			if (!l2cache_enabled) {
171 				exynos_smc(SMC_CMD_L2X0INVALL, 0, 0, 0);
172 				l2cache_enabled = 1;
173 			}
174 		} else {
175 			l2cache_enabled = 0;
176 		}
177 		exynos_smc(SMC_CMD_L2X0CTRL, val, 0, 0);
178 		break;
179 
180 	case L2X0_DEBUG_CTRL:
181 		exynos_smc(SMC_CMD_L2X0DEBUG, val, 0, 0);
182 		break;
183 
184 	default:
185 		WARN_ONCE(1, "%s: ignoring write to reg 0x%x\n", __func__, reg);
186 	}
187 }
188 
189 static void exynos_l2_configure(const struct l2x0_regs *regs)
190 {
191 	exynos_smc(SMC_CMD_L2X0SETUP1, regs->tag_latency, regs->data_latency,
192 		   regs->prefetch_ctrl);
193 	exynos_smc(SMC_CMD_L2X0SETUP2, regs->pwr_ctrl, regs->aux_ctrl, 0);
194 }
195 
196 bool __init exynos_secure_firmware_available(void)
197 {
198 	struct device_node *nd;
199 	const __be32 *addr;
200 
201 	nd = of_find_compatible_node(NULL, NULL,
202 					"samsung,secure-firmware");
203 	if (!nd)
204 		return false;
205 
206 	addr = of_get_address(nd, 0, NULL, NULL);
207 	of_node_put(nd);
208 	if (!addr) {
209 		pr_err("%s: No address specified.\n", __func__);
210 		return false;
211 	}
212 
213 	return true;
214 }
215 
216 void __init exynos_firmware_init(void)
217 {
218 	if (!exynos_secure_firmware_available())
219 		return;
220 
221 	pr_info("Running under secure firmware.\n");
222 
223 	register_firmware_ops(&exynos_firmware_ops);
224 
225 	/*
226 	 * Exynos 4 SoCs (based on Cortex A9 and equipped with L2C-310),
227 	 * running under secure firmware, require certain registers of L2
228 	 * cache controller to be written in secure mode. Here .write_sec
229 	 * callback is provided to perform necessary SMC calls.
230 	 */
231 	if (IS_ENABLED(CONFIG_CACHE_L2X0) &&
232 	    read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
233 		outer_cache.write_sec = exynos_l2_write_sec;
234 		outer_cache.configure = exynos_l2_configure;
235 	}
236 }
237 
238 #define REG_CPU_STATE_ADDR	(sysram_ns_base_addr + 0x28)
239 #define BOOT_MODE_MASK		0x1f
240 
241 void exynos_set_boot_flag(unsigned int cpu, unsigned int mode)
242 {
243 	unsigned int tmp;
244 
245 	tmp = readl_relaxed(REG_CPU_STATE_ADDR + cpu * 4);
246 
247 	if (mode & BOOT_MODE_MASK)
248 		tmp &= ~BOOT_MODE_MASK;
249 
250 	tmp |= mode;
251 	writel_relaxed(tmp, REG_CPU_STATE_ADDR + cpu * 4);
252 }
253 
254 void exynos_clear_boot_flag(unsigned int cpu, unsigned int mode)
255 {
256 	unsigned int tmp;
257 
258 	tmp = readl_relaxed(REG_CPU_STATE_ADDR + cpu * 4);
259 	tmp &= ~mode;
260 	writel_relaxed(tmp, REG_CPU_STATE_ADDR + cpu * 4);
261 }
262