1 /*
2  * Copyright (c) 2017-2021, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 
9 #include <platform_def.h>
10 
11 #include <arch_helpers.h>
12 #include <common/debug.h>
13 #include <drivers/arm/css/css_scpi.h>
14 #include <drivers/arm/gicv2.h>
15 #include <drivers/delay_timer.h>
16 #include <lib/mmio.h>
17 #include <lib/psci/psci.h>
18 #include <plat/common/platform.h>
19 
20 #include <sunxi_cpucfg.h>
21 #include <sunxi_def.h>
22 #include <sunxi_mmap.h>
23 #include <sunxi_private.h>
24 
25 #define SUNXI_WDOG0_CTRL_REG		(SUNXI_R_WDOG_BASE + 0x0010)
26 #define SUNXI_WDOG0_CFG_REG		(SUNXI_R_WDOG_BASE + 0x0014)
27 #define SUNXI_WDOG0_MODE_REG		(SUNXI_R_WDOG_BASE + 0x0018)
28 
29 #define CPU_PWR_LVL			MPIDR_AFFLVL0
30 #define CLUSTER_PWR_LVL			MPIDR_AFFLVL1
31 #define SYSTEM_PWR_LVL			MPIDR_AFFLVL2
32 
33 #define CPU_PWR_STATE(state) \
34 	((state)->pwr_domain_state[CPU_PWR_LVL])
35 #define CLUSTER_PWR_STATE(state) \
36 	((state)->pwr_domain_state[CLUSTER_PWR_LVL])
37 #define SYSTEM_PWR_STATE(state) \
38 	((state)->pwr_domain_state[SYSTEM_PWR_LVL])
39 
40 /*
41  * The addresses for the SCP exception vectors are defined in the or1k
42  * architecture specification.
43  */
44 #define OR1K_VEC_FIRST			0x01
45 #define OR1K_VEC_LAST			0x0e
46 #define OR1K_VEC_ADDR(n)		(0x100 * (n))
47 
48 /*
49  * This magic value is the little-endian representation of the or1k
50  * instruction "l.mfspr r2, r0, 0x12", which is guaranteed to be the
51  * first instruction in the SCP firmware.
52  */
53 #define SCP_FIRMWARE_MAGIC		0xb4400012
54 
55 static bool scpi_available;
56 
scpi_map_state(plat_local_state_t psci_state)57 static inline scpi_power_state_t scpi_map_state(plat_local_state_t psci_state)
58 {
59 	if (is_local_state_run(psci_state))
60 		return scpi_power_on;
61 	if (is_local_state_retn(psci_state))
62 		return scpi_power_retention;
63 	return scpi_power_off;
64 }
65 
sunxi_cpu_standby(plat_local_state_t cpu_state)66 static void sunxi_cpu_standby(plat_local_state_t cpu_state)
67 {
68 	u_register_t scr = read_scr_el3();
69 
70 	assert(is_local_state_retn(cpu_state));
71 
72 	write_scr_el3(scr | SCR_IRQ_BIT);
73 	wfi();
74 	write_scr_el3(scr);
75 }
76 
sunxi_pwr_domain_on(u_register_t mpidr)77 static int sunxi_pwr_domain_on(u_register_t mpidr)
78 {
79 	if (scpi_available) {
80 		scpi_set_css_power_state(mpidr,
81 					 scpi_power_on,
82 					 scpi_power_on,
83 					 scpi_power_on);
84 	} else {
85 		sunxi_cpu_on(mpidr);
86 	}
87 
88 	return PSCI_E_SUCCESS;
89 }
90 
sunxi_pwr_domain_off(const psci_power_state_t * target_state)91 static void sunxi_pwr_domain_off(const psci_power_state_t *target_state)
92 {
93 	plat_local_state_t cpu_pwr_state     = CPU_PWR_STATE(target_state);
94 	plat_local_state_t cluster_pwr_state = CLUSTER_PWR_STATE(target_state);
95 	plat_local_state_t system_pwr_state  = SYSTEM_PWR_STATE(target_state);
96 
97 	if (is_local_state_off(cpu_pwr_state))
98 		gicv2_cpuif_disable();
99 
100 	if (scpi_available) {
101 		scpi_set_css_power_state(read_mpidr(),
102 					 scpi_map_state(cpu_pwr_state),
103 					 scpi_map_state(cluster_pwr_state),
104 					 scpi_map_state(system_pwr_state));
105 	}
106 }
107 
sunxi_pwr_down_wfi(const psci_power_state_t * target_state)108 static void __dead2 sunxi_pwr_down_wfi(const psci_power_state_t *target_state)
109 {
110 	sunxi_cpu_off(read_mpidr());
111 
112 	while (1)
113 		wfi();
114 }
115 
sunxi_pwr_domain_on_finish(const psci_power_state_t * target_state)116 static void sunxi_pwr_domain_on_finish(const psci_power_state_t *target_state)
117 {
118 	if (is_local_state_off(SYSTEM_PWR_STATE(target_state)))
119 		gicv2_distif_init();
120 	if (is_local_state_off(CPU_PWR_STATE(target_state))) {
121 		gicv2_pcpu_distif_init();
122 		gicv2_cpuif_enable();
123 	}
124 }
125 
sunxi_system_off(void)126 static void __dead2 sunxi_system_off(void)
127 {
128 	gicv2_cpuif_disable();
129 
130 	if (scpi_available) {
131 		/* Send the power down request to the SCP */
132 		uint32_t ret = scpi_sys_power_state(scpi_system_shutdown);
133 
134 		if (ret != SCP_OK)
135 			ERROR("PSCI: SCPI %s failed: %d\n", "shutdown", ret);
136 	}
137 
138 	/* Turn off all secondary CPUs */
139 	sunxi_disable_secondary_cpus(read_mpidr());
140 
141 	sunxi_power_down();
142 
143 	udelay(1000);
144 	ERROR("PSCI: Cannot turn off system, halting\n");
145 	wfi();
146 	panic();
147 }
148 
sunxi_system_reset(void)149 static void __dead2 sunxi_system_reset(void)
150 {
151 	gicv2_cpuif_disable();
152 
153 	if (scpi_available) {
154 		/* Send the system reset request to the SCP */
155 		uint32_t ret = scpi_sys_power_state(scpi_system_reboot);
156 
157 		if (ret != SCP_OK)
158 			ERROR("PSCI: SCPI %s failed: %d\n", "reboot", ret);
159 	}
160 
161 	/* Reset the whole system when the watchdog times out */
162 	mmio_write_32(SUNXI_WDOG0_CFG_REG, 1);
163 	/* Enable the watchdog with the shortest timeout (0.5 seconds) */
164 	mmio_write_32(SUNXI_WDOG0_MODE_REG, (0 << 4) | 1);
165 	/* Wait for twice the watchdog timeout before panicking */
166 	mdelay(1000);
167 
168 	ERROR("PSCI: System reset failed\n");
169 	wfi();
170 	panic();
171 }
172 
sunxi_validate_power_state(unsigned int power_state,psci_power_state_t * req_state)173 static int sunxi_validate_power_state(unsigned int power_state,
174 				      psci_power_state_t *req_state)
175 {
176 	unsigned int power_level = psci_get_pstate_pwrlvl(power_state);
177 	unsigned int type = psci_get_pstate_type(power_state);
178 
179 	assert(req_state != NULL);
180 
181 	if (power_level > PLAT_MAX_PWR_LVL)
182 		return PSCI_E_INVALID_PARAMS;
183 
184 	if (type == PSTATE_TYPE_STANDBY) {
185 		/* Only one retention power state is supported. */
186 		if (psci_get_pstate_id(power_state) > 0)
187 			return PSCI_E_INVALID_PARAMS;
188 		/* The SoC cannot be suspended without losing state */
189 		if (power_level == SYSTEM_PWR_LVL)
190 			return PSCI_E_INVALID_PARAMS;
191 		for (unsigned int i = 0; i <= power_level; ++i)
192 			req_state->pwr_domain_state[i] = PLAT_MAX_RET_STATE;
193 	} else {
194 		/* Only one off power state is supported. */
195 		if (psci_get_pstate_id(power_state) > 0)
196 			return PSCI_E_INVALID_PARAMS;
197 		for (unsigned int i = 0; i <= power_level; ++i)
198 			req_state->pwr_domain_state[i] = PLAT_MAX_OFF_STATE;
199 	}
200 	/* Higher power domain levels should all remain running */
201 	for (unsigned int i = power_level + 1; i <= PLAT_MAX_PWR_LVL; ++i)
202 		req_state->pwr_domain_state[i] = PSCI_LOCAL_STATE_RUN;
203 
204 	return PSCI_E_SUCCESS;
205 }
206 
sunxi_validate_ns_entrypoint(uintptr_t ns_entrypoint)207 static int sunxi_validate_ns_entrypoint(uintptr_t ns_entrypoint)
208 {
209 	/* The non-secure entry point must be in DRAM */
210 	if (ns_entrypoint < SUNXI_DRAM_BASE) {
211 		return PSCI_E_INVALID_ADDRESS;
212 	}
213 
214 	return PSCI_E_SUCCESS;
215 }
216 
sunxi_get_sys_suspend_power_state(psci_power_state_t * req_state)217 static void sunxi_get_sys_suspend_power_state(psci_power_state_t *req_state)
218 {
219 	assert(req_state);
220 
221 	for (unsigned int i = 0; i <= PLAT_MAX_PWR_LVL; ++i)
222 		req_state->pwr_domain_state[i] = PLAT_MAX_OFF_STATE;
223 }
224 
225 static plat_psci_ops_t sunxi_psci_ops = {
226 	.cpu_standby			= sunxi_cpu_standby,
227 	.pwr_domain_on			= sunxi_pwr_domain_on,
228 	.pwr_domain_off			= sunxi_pwr_domain_off,
229 	.pwr_domain_on_finish		= sunxi_pwr_domain_on_finish,
230 	.system_off			= sunxi_system_off,
231 	.system_reset			= sunxi_system_reset,
232 	.validate_power_state		= sunxi_validate_power_state,
233 	.validate_ns_entrypoint		= sunxi_validate_ns_entrypoint,
234 };
235 
plat_setup_psci_ops(uintptr_t sec_entrypoint,const plat_psci_ops_t ** psci_ops)236 int plat_setup_psci_ops(uintptr_t sec_entrypoint,
237 			const plat_psci_ops_t **psci_ops)
238 {
239 	assert(psci_ops);
240 
241 	/* Program all CPU entry points. */
242 	for (unsigned int cpu = 0; cpu < PLATFORM_CORE_COUNT; ++cpu) {
243 		mmio_write_32(SUNXI_CPUCFG_RVBAR_LO_REG(cpu),
244 			      sec_entrypoint & 0xffffffff);
245 		mmio_write_32(SUNXI_CPUCFG_RVBAR_HI_REG(cpu),
246 			      sec_entrypoint >> 32);
247 	}
248 
249 	/* Check for a valid SCP firmware, and boot the SCP if found. */
250 	if (mmio_read_32(SUNXI_SCP_BASE) == SCP_FIRMWARE_MAGIC) {
251 		/* Program SCP exception vectors to the firmware entrypoint. */
252 		for (unsigned int i = OR1K_VEC_FIRST; i <= OR1K_VEC_LAST; ++i) {
253 			uint32_t vector = SUNXI_SRAM_A2_BASE + OR1K_VEC_ADDR(i);
254 			uint32_t offset = SUNXI_SCP_BASE - vector;
255 
256 			mmio_write_32(vector, offset >> 2);
257 			clean_dcache_range(vector, sizeof(uint32_t));
258 		}
259 		/* Take the SCP out of reset. */
260 		mmio_setbits_32(SUNXI_R_CPUCFG_BASE, BIT(0));
261 		/* Wait for the SCP firmware to boot. */
262 		if (scpi_wait_ready() == 0)
263 			scpi_available = true;
264 	}
265 
266 	NOTICE("PSCI: System suspend is %s\n",
267 	       scpi_available ? "available via SCPI" : "unavailable");
268 	if (scpi_available) {
269 		/* Suspend is only available via SCPI. */
270 		sunxi_psci_ops.pwr_domain_suspend = sunxi_pwr_domain_off;
271 		sunxi_psci_ops.pwr_domain_suspend_finish = sunxi_pwr_domain_on_finish;
272 		sunxi_psci_ops.get_sys_suspend_power_state = sunxi_get_sys_suspend_power_state;
273 	} else {
274 		/* This is only needed when SCPI is unavailable. */
275 		sunxi_psci_ops.pwr_domain_pwr_down_wfi = sunxi_pwr_down_wfi;
276 	}
277 
278 	*psci_ops = &sunxi_psci_ops;
279 
280 	return 0;
281 }
282