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1 /*
2  * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 #include <string.h>
9 
10 #include <arch_helpers.h>
11 #include <common/debug.h>
12 #include <drivers/arm/css/css_scp.h>
13 #include <drivers/arm/css/scmi.h>
14 #include <plat/arm/common/plat_arm.h>
15 #include <plat/arm/css/common/css_pm.h>
16 #include <plat/common/platform.h>
17 #include <platform_def.h>
18 
19 /*
20  * This file implements the SCP helper functions using SCMI protocol.
21  */
22 
23 /*
24  * SCMI power state parameter bit field encoding for ARM CSS platforms.
25  *
26  * 31  20 19       16 15      12 11       8 7        4 3         0
27  * +-------------------------------------------------------------+
28  * | SBZ | Max level |  Level 3 |  Level 2 |  Level 1 |  Level 0 |
29  * |     |           |   state  |   state  |   state  |   state  |
30  * +-------------------------------------------------------------+
31  *
32  * `Max level` encodes the highest level that has a valid power state
33  * encoded in the power state.
34  */
35 #define SCMI_PWR_STATE_MAX_PWR_LVL_SHIFT	16
36 #define SCMI_PWR_STATE_MAX_PWR_LVL_WIDTH	4
37 #define SCMI_PWR_STATE_MAX_PWR_LVL_MASK		\
38 				((1 << SCMI_PWR_STATE_MAX_PWR_LVL_WIDTH) - 1)
39 #define SCMI_SET_PWR_STATE_MAX_PWR_LVL(_power_state, _max_level)		\
40 		(_power_state) |= ((_max_level) & SCMI_PWR_STATE_MAX_PWR_LVL_MASK)\
41 				<< SCMI_PWR_STATE_MAX_PWR_LVL_SHIFT
42 #define SCMI_GET_PWR_STATE_MAX_PWR_LVL(_power_state)		\
43 		(((_power_state) >> SCMI_PWR_STATE_MAX_PWR_LVL_SHIFT)	\
44 				& SCMI_PWR_STATE_MAX_PWR_LVL_MASK)
45 
46 #define SCMI_PWR_STATE_LVL_WIDTH		4
47 #define SCMI_PWR_STATE_LVL_MASK			\
48 				((1 << SCMI_PWR_STATE_LVL_WIDTH) - 1)
49 #define SCMI_SET_PWR_STATE_LVL(_power_state, _level, _level_state)		\
50 		(_power_state) |= ((_level_state) & SCMI_PWR_STATE_LVL_MASK)	\
51 				<< (SCMI_PWR_STATE_LVL_WIDTH * (_level))
52 #define SCMI_GET_PWR_STATE_LVL(_power_state, _level)		\
53 		(((_power_state) >> (SCMI_PWR_STATE_LVL_WIDTH * (_level))) &	\
54 				SCMI_PWR_STATE_LVL_MASK)
55 
56 /*
57  * The SCMI power state enumeration for a power domain level
58  */
59 typedef enum {
60 	scmi_power_state_off = 0,
61 	scmi_power_state_on = 1,
62 	scmi_power_state_sleep = 2,
63 } scmi_power_state_t;
64 
65 /*
66  * The global handle for invoking the SCMI driver APIs after the driver
67  * has been initialized.
68  */
69 static void *scmi_handle;
70 
71 /* The SCMI channel global object */
72 static scmi_channel_t channel;
73 
74 ARM_SCMI_INSTANTIATE_LOCK;
75 
76 /*
77  * Helper function to suspend a CPU power domain and its parent power domains
78  * if applicable.
79  */
css_scp_suspend(const struct psci_power_state * target_state)80 void css_scp_suspend(const struct psci_power_state *target_state)
81 {
82 	int ret;
83 
84 	/* At least power domain level 0 should be specified to be suspended */
85 	assert(target_state->pwr_domain_state[ARM_PWR_LVL0] ==
86 						ARM_LOCAL_STATE_OFF);
87 
88 	/* Check if power down at system power domain level is requested */
89 	if (css_system_pwr_state(target_state) == ARM_LOCAL_STATE_OFF) {
90 		/* Issue SCMI command for SYSTEM_SUSPEND */
91 		ret = scmi_sys_pwr_state_set(scmi_handle,
92 				SCMI_SYS_PWR_FORCEFUL_REQ,
93 				SCMI_SYS_PWR_SUSPEND);
94 		if (ret != SCMI_E_SUCCESS) {
95 			ERROR("SCMI system power domain suspend return 0x%x unexpected\n",
96 					ret);
97 			panic();
98 		}
99 		return;
100 	}
101 #if !HW_ASSISTED_COHERENCY
102 	unsigned int lvl;
103 	uint32_t scmi_pwr_state = 0;
104 	/*
105 	 * If we reach here, then assert that power down at system power domain
106 	 * level is running.
107 	 */
108 	assert(css_system_pwr_state(target_state) == ARM_LOCAL_STATE_RUN);
109 
110 	/* For level 0, specify `scmi_power_state_sleep` as the power state */
111 	SCMI_SET_PWR_STATE_LVL(scmi_pwr_state, ARM_PWR_LVL0,
112 						scmi_power_state_sleep);
113 
114 	for (lvl = ARM_PWR_LVL1; lvl <= PLAT_MAX_PWR_LVL; lvl++) {
115 		if (target_state->pwr_domain_state[lvl] == ARM_LOCAL_STATE_RUN)
116 			break;
117 
118 		assert(target_state->pwr_domain_state[lvl] ==
119 							ARM_LOCAL_STATE_OFF);
120 		/*
121 		 * Specify `scmi_power_state_off` as power state for higher
122 		 * levels.
123 		 */
124 		SCMI_SET_PWR_STATE_LVL(scmi_pwr_state, lvl,
125 						scmi_power_state_off);
126 	}
127 
128 	SCMI_SET_PWR_STATE_MAX_PWR_LVL(scmi_pwr_state, lvl - 1);
129 
130 	ret = scmi_pwr_state_set(scmi_handle,
131 		plat_css_core_pos_to_scmi_dmn_id_map[plat_my_core_pos()],
132 		scmi_pwr_state);
133 
134 	if (ret != SCMI_E_SUCCESS) {
135 		ERROR("SCMI set power state command return 0x%x unexpected\n",
136 				ret);
137 		panic();
138 	}
139 #endif
140 }
141 
142 /*
143  * Helper function to turn off a CPU power domain and its parent power domains
144  * if applicable.
145  */
css_scp_off(const struct psci_power_state * target_state)146 void css_scp_off(const struct psci_power_state *target_state)
147 {
148 	unsigned int lvl = 0;
149 	int ret;
150 	uint32_t scmi_pwr_state = 0;
151 
152 	/* At-least the CPU level should be specified to be OFF */
153 	assert(target_state->pwr_domain_state[ARM_PWR_LVL0] ==
154 							ARM_LOCAL_STATE_OFF);
155 
156 	/* PSCI CPU OFF cannot be used to turn OFF system power domain */
157 	assert(css_system_pwr_state(target_state) == ARM_LOCAL_STATE_RUN);
158 
159 	for (; lvl <= PLAT_MAX_PWR_LVL; lvl++) {
160 		if (target_state->pwr_domain_state[lvl] == ARM_LOCAL_STATE_RUN)
161 			break;
162 
163 		assert(target_state->pwr_domain_state[lvl] ==
164 							ARM_LOCAL_STATE_OFF);
165 		SCMI_SET_PWR_STATE_LVL(scmi_pwr_state, lvl,
166 				scmi_power_state_off);
167 	}
168 
169 	SCMI_SET_PWR_STATE_MAX_PWR_LVL(scmi_pwr_state, lvl - 1);
170 
171 	ret = scmi_pwr_state_set(scmi_handle,
172 		plat_css_core_pos_to_scmi_dmn_id_map[plat_my_core_pos()],
173 		scmi_pwr_state);
174 
175 	if (ret != SCMI_E_QUEUED && ret != SCMI_E_SUCCESS) {
176 		ERROR("SCMI set power state command return 0x%x unexpected\n",
177 				ret);
178 		panic();
179 	}
180 }
181 
182 /*
183  * Helper function to turn ON a CPU power domain and its parent power domains
184  * if applicable.
185  */
css_scp_on(u_register_t mpidr)186 void css_scp_on(u_register_t mpidr)
187 {
188 	unsigned int lvl = 0;
189 	int core_pos, ret;
190 	uint32_t scmi_pwr_state = 0;
191 
192 	for (; lvl <= PLAT_MAX_PWR_LVL; lvl++)
193 		SCMI_SET_PWR_STATE_LVL(scmi_pwr_state, lvl,
194 				scmi_power_state_on);
195 
196 	SCMI_SET_PWR_STATE_MAX_PWR_LVL(scmi_pwr_state, lvl - 1);
197 
198 	core_pos = plat_core_pos_by_mpidr(mpidr);
199 	assert((core_pos >= 0) &&
200 		(((unsigned int)core_pos) < PLATFORM_CORE_COUNT));
201 
202 	ret = scmi_pwr_state_set(scmi_handle,
203 		plat_css_core_pos_to_scmi_dmn_id_map[core_pos],
204 		scmi_pwr_state);
205 
206 	if (ret != SCMI_E_QUEUED && ret != SCMI_E_SUCCESS) {
207 		ERROR("SCMI set power state command return 0x%x unexpected\n",
208 				ret);
209 		panic();
210 	}
211 }
212 
213 /*
214  * Helper function to get the power state of a power domain node as reported
215  * by the SCP.
216  */
css_scp_get_power_state(u_register_t mpidr,unsigned int power_level)217 int css_scp_get_power_state(u_register_t mpidr, unsigned int power_level)
218 {
219 	int ret, cpu_idx;
220 	uint32_t scmi_pwr_state = 0, lvl_state;
221 
222 	/* We don't support get power state at the system power domain level */
223 	if ((power_level > PLAT_MAX_PWR_LVL) ||
224 			(power_level == CSS_SYSTEM_PWR_DMN_LVL)) {
225 		WARN("Invalid power level %u specified for SCMI get power state\n",
226 				power_level);
227 		return PSCI_E_INVALID_PARAMS;
228 	}
229 
230 	cpu_idx = plat_core_pos_by_mpidr(mpidr);
231 	assert(cpu_idx > -1);
232 
233 	ret = scmi_pwr_state_get(scmi_handle,
234 		plat_css_core_pos_to_scmi_dmn_id_map[cpu_idx],
235 		&scmi_pwr_state);
236 
237 	if (ret != SCMI_E_SUCCESS) {
238 		WARN("SCMI get power state command return 0x%x unexpected\n",
239 				ret);
240 		return PSCI_E_INVALID_PARAMS;
241 	}
242 
243 	/*
244 	 * Find the maximum power level described in the get power state
245 	 * command. If it is less than the requested power level, then assume
246 	 * the requested power level is ON.
247 	 */
248 	if (SCMI_GET_PWR_STATE_MAX_PWR_LVL(scmi_pwr_state) < power_level)
249 		return HW_ON;
250 
251 	lvl_state = SCMI_GET_PWR_STATE_LVL(scmi_pwr_state, power_level);
252 	if (lvl_state == scmi_power_state_on)
253 		return HW_ON;
254 
255 	assert((lvl_state == scmi_power_state_off) ||
256 				(lvl_state == scmi_power_state_sleep));
257 	return HW_OFF;
258 }
259 
css_scp_system_off(int state)260 void __dead2 css_scp_system_off(int state)
261 {
262 	int ret;
263 
264 	/*
265 	 * Disable GIC CPU interface to prevent pending interrupt from waking
266 	 * up the AP from WFI.
267 	 */
268 	plat_arm_gic_cpuif_disable();
269 
270 	/*
271 	 * Issue SCMI command. First issue a graceful
272 	 * request and if that fails force the request.
273 	 */
274 	ret = scmi_sys_pwr_state_set(scmi_handle,
275 			SCMI_SYS_PWR_FORCEFUL_REQ,
276 			state);
277 
278 	if (ret != SCMI_E_SUCCESS) {
279 		ERROR("SCMI system power state set 0x%x returns unexpected 0x%x\n",
280 			state, ret);
281 		panic();
282 	}
283 	wfi();
284 	ERROR("CSS set power state: operation not handled.\n");
285 	panic();
286 }
287 
288 /*
289  * Helper function to shutdown the system via SCMI.
290  */
css_scp_sys_shutdown(void)291 void __dead2 css_scp_sys_shutdown(void)
292 {
293 	css_scp_system_off(SCMI_SYS_PWR_SHUTDOWN);
294 }
295 
296 /*
297  * Helper function to reset the system via SCMI.
298  */
css_scp_sys_reboot(void)299 void __dead2 css_scp_sys_reboot(void)
300 {
301 	css_scp_system_off(SCMI_SYS_PWR_COLD_RESET);
302 }
303 
scmi_ap_core_init(scmi_channel_t * ch)304 static int scmi_ap_core_init(scmi_channel_t *ch)
305 {
306 #if PROGRAMMABLE_RESET_ADDRESS
307 	uint32_t version;
308 	int ret;
309 
310 	ret = scmi_proto_version(ch, SCMI_AP_CORE_PROTO_ID, &version);
311 	if (ret != SCMI_E_SUCCESS) {
312 		WARN("SCMI AP core protocol version message failed\n");
313 		return -1;
314 	}
315 
316 	if (!is_scmi_version_compatible(SCMI_AP_CORE_PROTO_VER, version)) {
317 		WARN("SCMI AP core protocol version 0x%x incompatible with driver version 0x%x\n",
318 			version, SCMI_AP_CORE_PROTO_VER);
319 		return -1;
320 	}
321 	INFO("SCMI AP core protocol version 0x%x detected\n", version);
322 #endif
323 	return 0;
324 }
325 
plat_arm_pwrc_setup(void)326 void __init plat_arm_pwrc_setup(void)
327 {
328 	channel.info = plat_css_get_scmi_info();
329 	channel.lock = ARM_SCMI_LOCK_GET_INSTANCE;
330 	scmi_handle = scmi_init(&channel);
331 	if (scmi_handle == NULL) {
332 		ERROR("SCMI Initialization failed\n");
333 		panic();
334 	}
335 	if (scmi_ap_core_init(&channel) < 0) {
336 		ERROR("SCMI AP core protocol initialization failed\n");
337 		panic();
338 	}
339 }
340 
341 /******************************************************************************
342  * This function overrides the default definition for ARM platforms. Initialize
343  * the SCMI driver, query capability via SCMI and modify the PSCI capability
344  * based on that.
345  *****************************************************************************/
css_scmi_override_pm_ops(plat_psci_ops_t * ops)346 const plat_psci_ops_t *css_scmi_override_pm_ops(plat_psci_ops_t *ops)
347 {
348 	uint32_t msg_attr;
349 	int ret;
350 
351 	assert(scmi_handle);
352 
353 	/* Check that power domain POWER_STATE_SET message is supported */
354 	ret = scmi_proto_msg_attr(scmi_handle, SCMI_PWR_DMN_PROTO_ID,
355 				SCMI_PWR_STATE_SET_MSG, &msg_attr);
356 	if (ret != SCMI_E_SUCCESS) {
357 		ERROR("Set power state command is not supported by SCMI\n");
358 		panic();
359 	}
360 
361 	/*
362 	 * Don't support PSCI NODE_HW_STATE call if SCMI doesn't support
363 	 * POWER_STATE_GET message.
364 	 */
365 	ret = scmi_proto_msg_attr(scmi_handle, SCMI_PWR_DMN_PROTO_ID,
366 				SCMI_PWR_STATE_GET_MSG, &msg_attr);
367 	if (ret != SCMI_E_SUCCESS)
368 		ops->get_node_hw_state = NULL;
369 
370 	/* Check if the SCMI SYSTEM_POWER_STATE_SET message is supported */
371 	ret = scmi_proto_msg_attr(scmi_handle, SCMI_SYS_PWR_PROTO_ID,
372 				SCMI_SYS_PWR_STATE_SET_MSG, &msg_attr);
373 	if (ret != SCMI_E_SUCCESS) {
374 		/* System power management operations are not supported */
375 		ops->system_off = NULL;
376 		ops->system_reset = NULL;
377 		ops->get_sys_suspend_power_state = NULL;
378 	} else {
379 		if (!(msg_attr & SCMI_SYS_PWR_SUSPEND_SUPPORTED)) {
380 			/*
381 			 * System power management protocol is available, but
382 			 * it does not support SYSTEM SUSPEND.
383 			 */
384 			ops->get_sys_suspend_power_state = NULL;
385 		}
386 		if (!(msg_attr & SCMI_SYS_PWR_WARM_RESET_SUPPORTED)) {
387 			/*
388 			 * WARM reset is not available.
389 			 */
390 			ops->system_reset2 = NULL;
391 		}
392 	}
393 
394 	return ops;
395 }
396 
css_system_reset2(int is_vendor,int reset_type,u_register_t cookie)397 int css_system_reset2(int is_vendor, int reset_type, u_register_t cookie)
398 {
399 	if (is_vendor || (reset_type != PSCI_RESET2_SYSTEM_WARM_RESET))
400 		return PSCI_E_INVALID_PARAMS;
401 
402 	css_scp_system_off(SCMI_SYS_PWR_WARM_RESET);
403 	/*
404 	 * css_scp_system_off cannot return (it is a __dead function),
405 	 * but css_system_reset2 has to return some value, even in
406 	 * this case.
407 	 */
408 	return 0;
409 }
410 
411 #if PROGRAMMABLE_RESET_ADDRESS
plat_arm_program_trusted_mailbox(uintptr_t address)412 void plat_arm_program_trusted_mailbox(uintptr_t address)
413 {
414 	int ret;
415 
416 	assert(scmi_handle);
417 	ret = scmi_ap_core_set_reset_addr(scmi_handle, address,
418 		SCMI_AP_CORE_LOCK_ATTR);
419 	if (ret != SCMI_E_SUCCESS) {
420 		ERROR("CSS: Failed to program reset address: %d\n", ret);
421 		panic();
422 	}
423 }
424 #endif
425