1 /*
2  * Copyright (c) 2015-2018, 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/console.h>
14 #include <lib/mmio.h>
15 #include <lib/psci/psci.h>
16 #include <plat/common/platform.h>
17 
18 #include <rpi_hw.h>
19 
20 #ifdef RPI_HAVE_GIC
21 #include <drivers/arm/gicv2.h>
22 #endif
23 
24 /* Make composite power state parameter till power level 0 */
25 #if PSCI_EXTENDED_STATE_ID
26 
27 #define rpi3_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type) \
28 		(((lvl0_state) << PSTATE_ID_SHIFT) | \
29 		 ((type) << PSTATE_TYPE_SHIFT))
30 
31 #else
32 
33 #define rpi3_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type) \
34 		(((lvl0_state) << PSTATE_ID_SHIFT) | \
35 		 ((pwr_lvl) << PSTATE_PWR_LVL_SHIFT) | \
36 		 ((type) << PSTATE_TYPE_SHIFT))
37 
38 #endif /* PSCI_EXTENDED_STATE_ID */
39 
40 #define rpi3_make_pwrstate_lvl1(lvl1_state, lvl0_state, pwr_lvl, type) \
41 		(((lvl1_state) << PLAT_LOCAL_PSTATE_WIDTH) | \
42 		 rpi3_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type))
43 
44 /*
45  *  The table storing the valid idle power states. Ensure that the
46  *  array entries are populated in ascending order of state-id to
47  *  enable us to use binary search during power state validation.
48  *  The table must be terminated by a NULL entry.
49  */
50 static const unsigned int rpi3_pm_idle_states[] = {
51 	/* State-id - 0x01 */
52 	rpi3_make_pwrstate_lvl1(PLAT_LOCAL_STATE_RUN, PLAT_LOCAL_STATE_RET,
53 				MPIDR_AFFLVL0, PSTATE_TYPE_STANDBY),
54 	/* State-id - 0x02 */
55 	rpi3_make_pwrstate_lvl1(PLAT_LOCAL_STATE_RUN, PLAT_LOCAL_STATE_OFF,
56 				MPIDR_AFFLVL0, PSTATE_TYPE_POWERDOWN),
57 	/* State-id - 0x22 */
58 	rpi3_make_pwrstate_lvl1(PLAT_LOCAL_STATE_OFF, PLAT_LOCAL_STATE_OFF,
59 				MPIDR_AFFLVL1, PSTATE_TYPE_POWERDOWN),
60 	0,
61 };
62 
63 /*******************************************************************************
64  * Platform handler called to check the validity of the power state
65  * parameter. The power state parameter has to be a composite power state.
66  ******************************************************************************/
rpi3_validate_power_state(unsigned int power_state,psci_power_state_t * req_state)67 static int rpi3_validate_power_state(unsigned int power_state,
68 				     psci_power_state_t *req_state)
69 {
70 	unsigned int state_id;
71 	int i;
72 
73 	assert(req_state != 0);
74 
75 	/*
76 	 *  Currently we are using a linear search for finding the matching
77 	 *  entry in the idle power state array. This can be made a binary
78 	 *  search if the number of entries justify the additional complexity.
79 	 */
80 	for (i = 0; rpi3_pm_idle_states[i] != 0; i++) {
81 		if (power_state == rpi3_pm_idle_states[i]) {
82 			break;
83 		}
84 	}
85 
86 	/* Return error if entry not found in the idle state array */
87 	if (!rpi3_pm_idle_states[i]) {
88 		return PSCI_E_INVALID_PARAMS;
89 	}
90 
91 	i = 0;
92 	state_id = psci_get_pstate_id(power_state);
93 
94 	/* Parse the State ID and populate the state info parameter */
95 	while (state_id) {
96 		req_state->pwr_domain_state[i++] = state_id &
97 						PLAT_LOCAL_PSTATE_MASK;
98 		state_id >>= PLAT_LOCAL_PSTATE_WIDTH;
99 	}
100 
101 	return PSCI_E_SUCCESS;
102 }
103 
104 /*******************************************************************************
105  * Platform handler called when a CPU is about to enter standby.
106  ******************************************************************************/
rpi3_cpu_standby(plat_local_state_t cpu_state)107 static void rpi3_cpu_standby(plat_local_state_t cpu_state)
108 {
109 	assert(cpu_state == PLAT_LOCAL_STATE_RET);
110 
111 	/*
112 	 * Enter standby state.
113 	 * dsb is good practice before using wfi to enter low power states
114 	 */
115 	dsb();
116 	wfi();
117 }
118 
rpi3_pwr_domain_off(const psci_power_state_t * target_state)119 static void rpi3_pwr_domain_off(const psci_power_state_t *target_state)
120 {
121 #ifdef RPI_HAVE_GIC
122 	gicv2_cpuif_disable();
123 #endif
124 }
125 
126 void __dead2 plat_secondary_cold_boot_setup(void);
127 
128 static void __dead2
rpi3_pwr_domain_pwr_down_wfi(const psci_power_state_t * target_state)129 rpi3_pwr_domain_pwr_down_wfi(const psci_power_state_t *target_state)
130 {
131 	disable_mmu_el3();
132 	plat_secondary_cold_boot_setup();
133 }
134 
135 /*******************************************************************************
136  * Platform handler called when a power domain is about to be turned on. The
137  * mpidr determines the CPU to be turned on.
138  ******************************************************************************/
rpi3_pwr_domain_on(u_register_t mpidr)139 static int rpi3_pwr_domain_on(u_register_t mpidr)
140 {
141 	int rc = PSCI_E_SUCCESS;
142 	unsigned int pos = plat_core_pos_by_mpidr(mpidr);
143 	uintptr_t hold_base = PLAT_RPI3_TM_HOLD_BASE;
144 
145 	assert(pos < PLATFORM_CORE_COUNT);
146 
147 	hold_base += pos * PLAT_RPI3_TM_HOLD_ENTRY_SIZE;
148 
149 	mmio_write_64(hold_base, PLAT_RPI3_TM_HOLD_STATE_GO);
150 	/* No cache maintenance here, hold_base is mapped as device memory. */
151 
152 	/* Make sure that the write has completed */
153 	dsb();
154 	isb();
155 
156 	sev();
157 
158 	return rc;
159 }
160 
161 /*******************************************************************************
162  * Platform handler called when a power domain has just been powered on after
163  * being turned off earlier. The target_state encodes the low power state that
164  * each level has woken up from.
165  ******************************************************************************/
rpi3_pwr_domain_on_finish(const psci_power_state_t * target_state)166 static void rpi3_pwr_domain_on_finish(const psci_power_state_t *target_state)
167 {
168 	assert(target_state->pwr_domain_state[MPIDR_AFFLVL0] ==
169 					PLAT_LOCAL_STATE_OFF);
170 
171 #ifdef RPI_HAVE_GIC
172 	gicv2_pcpu_distif_init();
173 	gicv2_cpuif_enable();
174 #endif
175 }
176 
rpi3_pwr_down_wfi(const psci_power_state_t * target_state)177 static void __dead2 rpi3_pwr_down_wfi(
178 		const psci_power_state_t *target_state)
179 {
180 	uintptr_t hold_base = PLAT_RPI3_TM_HOLD_BASE;
181 	unsigned int pos = plat_my_core_pos();
182 
183 	if (pos == 0) {
184 		/*
185 		 * The secondaries will always be in a wait
186 		 * for warm boot on reset, but the BSP needs
187 		 * to be able to distinguish between waiting
188 		 * for warm boot (e.g. after psci_off, waiting
189 		 * for psci_on) and a cold boot.
190 		 */
191 		mmio_write_64(hold_base, PLAT_RPI3_TM_HOLD_STATE_BSP_OFF);
192 		/* No cache maintenance here, we run with caches off already. */
193 		dsb();
194 		isb();
195 	}
196 
197 	write_rmr_el3(RMR_EL3_RR_BIT | RMR_EL3_AA64_BIT);
198 
199 	while (1)
200 		;
201 }
202 
203 /*******************************************************************************
204  * Platform handlers for system reset and system off.
205  ******************************************************************************/
206 
207 /* 10 ticks (Watchdog timer = Timer clock / 16) */
208 #define RESET_TIMEOUT	U(10)
209 
rpi3_watchdog_reset(void)210 static void __dead2 rpi3_watchdog_reset(void)
211 {
212 	uint32_t rstc;
213 
214 	console_flush();
215 
216 	dsbsy();
217 	isb();
218 
219 	mmio_write_32(RPI3_PM_BASE + RPI3_PM_WDOG_OFFSET,
220 		      RPI3_PM_PASSWORD | RESET_TIMEOUT);
221 
222 	rstc = mmio_read_32(RPI3_PM_BASE + RPI3_PM_RSTC_OFFSET);
223 	rstc &= ~RPI3_PM_RSTC_WRCFG_MASK;
224 	rstc |= RPI3_PM_PASSWORD | RPI3_PM_RSTC_WRCFG_FULL_RESET;
225 	mmio_write_32(RPI3_PM_BASE + RPI3_PM_RSTC_OFFSET, rstc);
226 
227 	for (;;) {
228 		wfi();
229 	}
230 }
231 
rpi3_system_reset(void)232 static void __dead2 rpi3_system_reset(void)
233 {
234 	INFO("rpi3: PSCI_SYSTEM_RESET: Invoking watchdog reset\n");
235 
236 	rpi3_watchdog_reset();
237 }
238 
rpi3_system_off(void)239 static void __dead2 rpi3_system_off(void)
240 {
241 	uint32_t rsts;
242 
243 	INFO("rpi3: PSCI_SYSTEM_OFF: Invoking watchdog reset\n");
244 
245 	/*
246 	 * This function doesn't actually make the Raspberry Pi turn itself off,
247 	 * the hardware doesn't allow it. It simply reboots it and the RSTS
248 	 * value tells the bootcode.bin firmware not to continue the regular
249 	 * bootflow and to stay in a low power mode.
250 	 */
251 
252 	rsts = mmio_read_32(RPI3_PM_BASE + RPI3_PM_RSTS_OFFSET);
253 	rsts |= RPI3_PM_PASSWORD | RPI3_PM_RSTS_WRCFG_HALT;
254 	mmio_write_32(RPI3_PM_BASE + RPI3_PM_RSTS_OFFSET, rsts);
255 
256 	rpi3_watchdog_reset();
257 }
258 
259 /*******************************************************************************
260  * Platform handlers and setup function.
261  ******************************************************************************/
262 static const plat_psci_ops_t plat_rpi3_psci_pm_ops = {
263 	.cpu_standby = rpi3_cpu_standby,
264 	.pwr_domain_off = rpi3_pwr_domain_off,
265 	.pwr_domain_pwr_down_wfi = rpi3_pwr_domain_pwr_down_wfi,
266 	.pwr_domain_on = rpi3_pwr_domain_on,
267 	.pwr_domain_on_finish = rpi3_pwr_domain_on_finish,
268 	.pwr_domain_pwr_down_wfi = rpi3_pwr_down_wfi,
269 	.system_off = rpi3_system_off,
270 	.system_reset = rpi3_system_reset,
271 	.validate_power_state = rpi3_validate_power_state,
272 };
273 
plat_setup_psci_ops(uintptr_t sec_entrypoint,const plat_psci_ops_t ** psci_ops)274 int plat_setup_psci_ops(uintptr_t sec_entrypoint,
275 			const plat_psci_ops_t **psci_ops)
276 {
277 	uintptr_t *entrypoint = (void *) PLAT_RPI3_TM_ENTRYPOINT;
278 
279 	*entrypoint = sec_entrypoint;
280 	*psci_ops = &plat_rpi3_psci_pm_ops;
281 
282 	return 0;
283 }
284