xref: /openbmc/linux/arch/arm/mach-meson/platsmp.c (revision ac8fa1bd) 
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2015 Carlo Caione <carlo@endlessm.com>
4  * Copyright (C) 2017 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
5  */
6 
7 #include <linux/delay.h>
8 #include <linux/init.h>
9 #include <linux/io.h>
10 #include <linux/of.h>
11 #include <linux/of_address.h>
12 #include <linux/regmap.h>
13 #include <linux/reset.h>
14 #include <linux/smp.h>
15 #include <linux/mfd/syscon.h>
16 
17 #include <asm/cacheflush.h>
18 #include <asm/cp15.h>
19 #include <asm/smp_scu.h>
20 #include <asm/smp_plat.h>
21 
22 #define MESON_SMP_SRAM_CPU_CTRL_REG		(0x00)
23 #define MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(c)	(0x04 + ((c - 1) << 2))
24 
25 #define MESON_CPU_AO_RTI_PWR_A9_CNTL0		(0x00)
26 #define MESON_CPU_AO_RTI_PWR_A9_CNTL1		(0x04)
27 #define MESON_CPU_AO_RTI_PWR_A9_MEM_PD0		(0x14)
28 
29 #define MESON_CPU_PWR_A9_CNTL0_M(c)		(0x03 << ((c * 2) + 16))
30 #define MESON_CPU_PWR_A9_CNTL1_M(c)		(0x03 << ((c + 1) << 1))
31 #define MESON_CPU_PWR_A9_MEM_PD0_M(c)		(0x0f << (32 - (c * 4)))
32 #define MESON_CPU_PWR_A9_CNTL1_ST(c)		(0x01 << (c + 16))
33 
34 static void __iomem *sram_base;
35 static void __iomem *scu_base;
36 static struct regmap *pmu;
37 
38 static struct reset_control *meson_smp_get_core_reset(int cpu)
39 {
40 	struct device_node *np = of_get_cpu_node(cpu, 0);
41 
42 	return of_reset_control_get_exclusive(np, NULL);
43 }
44 
45 static void meson_smp_set_cpu_ctrl(int cpu, bool on_off)
46 {
47 	u32 val = readl(sram_base + MESON_SMP_SRAM_CPU_CTRL_REG);
48 
49 	if (on_off)
50 		val |= BIT(cpu);
51 	else
52 		val &= ~BIT(cpu);
53 
54 	/* keep bit 0 always enabled */
55 	val |= BIT(0);
56 
57 	writel(val, sram_base + MESON_SMP_SRAM_CPU_CTRL_REG);
58 }
59 
60 static void __init meson_smp_prepare_cpus(const char *scu_compatible,
61 					  const char *pmu_compatible,
62 					  const char *sram_compatible)
63 {
64 	static struct device_node *node;
65 
66 	/* SMP SRAM */
67 	node = of_find_compatible_node(NULL, NULL, sram_compatible);
68 	if (!node) {
69 		pr_err("Missing SRAM node\n");
70 		return;
71 	}
72 
73 	sram_base = of_iomap(node, 0);
74 	if (!sram_base) {
75 		pr_err("Couldn't map SRAM registers\n");
76 		return;
77 	}
78 
79 	/* PMU */
80 	pmu = syscon_regmap_lookup_by_compatible(pmu_compatible);
81 	if (IS_ERR(pmu)) {
82 		pr_err("Couldn't map PMU registers\n");
83 		return;
84 	}
85 
86 	/* SCU */
87 	node = of_find_compatible_node(NULL, NULL, scu_compatible);
88 	if (!node) {
89 		pr_err("Missing SCU node\n");
90 		return;
91 	}
92 
93 	scu_base = of_iomap(node, 0);
94 	if (!scu_base) {
95 		pr_err("Couldn't map SCU registers\n");
96 		return;
97 	}
98 
99 	scu_enable(scu_base);
100 }
101 
102 static void __init meson8b_smp_prepare_cpus(unsigned int max_cpus)
103 {
104 	meson_smp_prepare_cpus("arm,cortex-a5-scu", "amlogic,meson8b-pmu",
105 			       "amlogic,meson8b-smp-sram");
106 }
107 
108 static void __init meson8_smp_prepare_cpus(unsigned int max_cpus)
109 {
110 	meson_smp_prepare_cpus("arm,cortex-a9-scu", "amlogic,meson8-pmu",
111 			       "amlogic,meson8-smp-sram");
112 }
113 
114 static void meson_smp_begin_secondary_boot(unsigned int cpu)
115 {
116 	/*
117 	 * Set the entry point before powering on the CPU through the SCU. This
118 	 * is needed if the CPU is in "warm" state (= after rebooting the
119 	 * system without power-cycling, or when taking the CPU offline and
120 	 * then taking it online again.
121 	 */
122 	writel(__pa_symbol(secondary_startup),
123 	       sram_base + MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(cpu));
124 
125 	/*
126 	 * SCU Power on CPU (needs to be done before starting the CPU,
127 	 * otherwise the secondary CPU will not start).
128 	 */
129 	scu_cpu_power_enable(scu_base, cpu);
130 }
131 
132 static int meson_smp_finalize_secondary_boot(unsigned int cpu)
133 {
134 	unsigned long timeout;
135 
136 	timeout = jiffies + (10 * HZ);
137 	while (readl(sram_base + MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(cpu))) {
138 		if (!time_before(jiffies, timeout)) {
139 			pr_err("Timeout while waiting for CPU%d status\n",
140 			       cpu);
141 			return -ETIMEDOUT;
142 		}
143 	}
144 
145 	writel(__pa_symbol(secondary_startup),
146 	       sram_base + MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(cpu));
147 
148 	meson_smp_set_cpu_ctrl(cpu, true);
149 
150 	return 0;
151 }
152 
153 static int meson8_smp_boot_secondary(unsigned int cpu,
154 				     struct task_struct *idle)
155 {
156 	struct reset_control *rstc;
157 	int ret;
158 
159 	rstc = meson_smp_get_core_reset(cpu);
160 	if (IS_ERR(rstc)) {
161 		pr_err("Couldn't get the reset controller for CPU%d\n", cpu);
162 		return PTR_ERR(rstc);
163 	}
164 
165 	meson_smp_begin_secondary_boot(cpu);
166 
167 	/* Reset enable */
168 	ret = reset_control_assert(rstc);
169 	if (ret) {
170 		pr_err("Failed to assert CPU%d reset\n", cpu);
171 		goto out;
172 	}
173 
174 	/* CPU power ON */
175 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
176 				 MESON_CPU_PWR_A9_CNTL1_M(cpu), 0);
177 	if (ret < 0) {
178 		pr_err("Couldn't wake up CPU%d\n", cpu);
179 		goto out;
180 	}
181 
182 	udelay(10);
183 
184 	/* Isolation disable */
185 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
186 				 0);
187 	if (ret < 0) {
188 		pr_err("Error when disabling isolation of CPU%d\n", cpu);
189 		goto out;
190 	}
191 
192 	/* Reset disable */
193 	ret = reset_control_deassert(rstc);
194 	if (ret) {
195 		pr_err("Failed to de-assert CPU%d reset\n", cpu);
196 		goto out;
197 	}
198 
199 	ret = meson_smp_finalize_secondary_boot(cpu);
200 	if (ret)
201 		goto out;
202 
203 out:
204 	reset_control_put(rstc);
205 
206 	return 0;
207 }
208 
209 static int meson8b_smp_boot_secondary(unsigned int cpu,
210 				     struct task_struct *idle)
211 {
212 	struct reset_control *rstc;
213 	int ret;
214 	u32 val;
215 
216 	rstc = meson_smp_get_core_reset(cpu);
217 	if (IS_ERR(rstc)) {
218 		pr_err("Couldn't get the reset controller for CPU%d\n", cpu);
219 		return PTR_ERR(rstc);
220 	}
221 
222 	meson_smp_begin_secondary_boot(cpu);
223 
224 	/* CPU power UP */
225 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0,
226 				 MESON_CPU_PWR_A9_CNTL0_M(cpu), 0);
227 	if (ret < 0) {
228 		pr_err("Couldn't power up CPU%d\n", cpu);
229 		goto out;
230 	}
231 
232 	udelay(5);
233 
234 	/* Reset enable */
235 	ret = reset_control_assert(rstc);
236 	if (ret) {
237 		pr_err("Failed to assert CPU%d reset\n", cpu);
238 		goto out;
239 	}
240 
241 	/* Memory power UP */
242 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_MEM_PD0,
243 				 MESON_CPU_PWR_A9_MEM_PD0_M(cpu), 0);
244 	if (ret < 0) {
245 		pr_err("Couldn't power up the memory for CPU%d\n", cpu);
246 		goto out;
247 	}
248 
249 	/* Wake up CPU */
250 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
251 				 MESON_CPU_PWR_A9_CNTL1_M(cpu), 0);
252 	if (ret < 0) {
253 		pr_err("Couldn't wake up CPU%d\n", cpu);
254 		goto out;
255 	}
256 
257 	udelay(10);
258 
259 	ret = regmap_read_poll_timeout(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1, val,
260 				       val & MESON_CPU_PWR_A9_CNTL1_ST(cpu),
261 				       10, 10000);
262 	if (ret) {
263 		pr_err("Timeout while polling PMU for CPU%d status\n", cpu);
264 		goto out;
265 	}
266 
267 	/* Isolation disable */
268 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
269 				 0);
270 	if (ret < 0) {
271 		pr_err("Error when disabling isolation of CPU%d\n", cpu);
272 		goto out;
273 	}
274 
275 	/* Reset disable */
276 	ret = reset_control_deassert(rstc);
277 	if (ret) {
278 		pr_err("Failed to de-assert CPU%d reset\n", cpu);
279 		goto out;
280 	}
281 
282 	ret = meson_smp_finalize_secondary_boot(cpu);
283 	if (ret)
284 		goto out;
285 
286 out:
287 	reset_control_put(rstc);
288 
289 	return 0;
290 }
291 
292 #ifdef CONFIG_HOTPLUG_CPU
293 static void meson8_smp_cpu_die(unsigned int cpu)
294 {
295 	meson_smp_set_cpu_ctrl(cpu, false);
296 
297 	v7_exit_coherency_flush(louis);
298 
299 	scu_power_mode(scu_base, SCU_PM_POWEROFF);
300 
301 	dsb();
302 	wfi();
303 
304 	/* we should never get here */
305 	WARN_ON(1);
306 }
307 
308 static int meson8_smp_cpu_kill(unsigned int cpu)
309 {
310 	int ret, power_mode;
311 	unsigned long timeout;
312 
313 	timeout = jiffies + (50 * HZ);
314 	do {
315 		power_mode = scu_get_cpu_power_mode(scu_base, cpu);
316 
317 		if (power_mode == SCU_PM_POWEROFF)
318 			break;
319 
320 		usleep_range(10000, 15000);
321 	} while (time_before(jiffies, timeout));
322 
323 	if (power_mode != SCU_PM_POWEROFF) {
324 		pr_err("Error while waiting for SCU power-off on CPU%d\n",
325 		       cpu);
326 		return -ETIMEDOUT;
327 	}
328 
329 	msleep(30);
330 
331 	/* Isolation enable */
332 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
333 				 0x3);
334 	if (ret < 0) {
335 		pr_err("Error when enabling isolation for CPU%d\n", cpu);
336 		return ret;
337 	}
338 
339 	udelay(10);
340 
341 	/* CPU power OFF */
342 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
343 				 MESON_CPU_PWR_A9_CNTL1_M(cpu), 0x3);
344 	if (ret < 0) {
345 		pr_err("Couldn't change sleep status of CPU%d\n", cpu);
346 		return ret;
347 	}
348 
349 	return 1;
350 }
351 
352 static int meson8b_smp_cpu_kill(unsigned int cpu)
353 {
354 	int ret, power_mode, count = 5000;
355 
356 	do {
357 		power_mode = scu_get_cpu_power_mode(scu_base, cpu);
358 
359 		if (power_mode == SCU_PM_POWEROFF)
360 			break;
361 
362 		udelay(10);
363 	} while (++count);
364 
365 	if (power_mode != SCU_PM_POWEROFF) {
366 		pr_err("Error while waiting for SCU power-off on CPU%d\n",
367 		       cpu);
368 		return -ETIMEDOUT;
369 	}
370 
371 	udelay(10);
372 
373 	/* CPU power DOWN */
374 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0,
375 				 MESON_CPU_PWR_A9_CNTL0_M(cpu), 0x3);
376 	if (ret < 0) {
377 		pr_err("Couldn't power down CPU%d\n", cpu);
378 		return ret;
379 	}
380 
381 	/* Isolation enable */
382 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
383 				 0x3);
384 	if (ret < 0) {
385 		pr_err("Error when enabling isolation for CPU%d\n", cpu);
386 		return ret;
387 	}
388 
389 	udelay(10);
390 
391 	/* Sleep status */
392 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
393 				 MESON_CPU_PWR_A9_CNTL1_M(cpu), 0x3);
394 	if (ret < 0) {
395 		pr_err("Couldn't change sleep status of CPU%d\n", cpu);
396 		return ret;
397 	}
398 
399 	/* Memory power DOWN */
400 	ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_MEM_PD0,
401 				 MESON_CPU_PWR_A9_MEM_PD0_M(cpu), 0xf);
402 	if (ret < 0) {
403 		pr_err("Couldn't power down the memory of CPU%d\n", cpu);
404 		return ret;
405 	}
406 
407 	return 1;
408 }
409 #endif
410 
411 static struct smp_operations meson8_smp_ops __initdata = {
412 	.smp_prepare_cpus	= meson8_smp_prepare_cpus,
413 	.smp_boot_secondary	= meson8_smp_boot_secondary,
414 #ifdef CONFIG_HOTPLUG_CPU
415 	.cpu_die		= meson8_smp_cpu_die,
416 	.cpu_kill		= meson8_smp_cpu_kill,
417 #endif
418 };
419 
420 static struct smp_operations meson8b_smp_ops __initdata = {
421 	.smp_prepare_cpus	= meson8b_smp_prepare_cpus,
422 	.smp_boot_secondary	= meson8b_smp_boot_secondary,
423 #ifdef CONFIG_HOTPLUG_CPU
424 	.cpu_die		= meson8_smp_cpu_die,
425 	.cpu_kill		= meson8b_smp_cpu_kill,
426 #endif
427 };
428 
429 CPU_METHOD_OF_DECLARE(meson8_smp, "amlogic,meson8-smp", &meson8_smp_ops);
430 CPU_METHOD_OF_DECLARE(meson8b_smp, "amlogic,meson8b-smp", &meson8b_smp_ops);
431