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 of_node_put(node);
75 if (!sram_base) {
76 pr_err("Couldn't map SRAM registers\n");
77 return;
78 }
79
80 /* PMU */
81 pmu = syscon_regmap_lookup_by_compatible(pmu_compatible);
82 if (IS_ERR(pmu)) {
83 pr_err("Couldn't map PMU registers\n");
84 return;
85 }
86
87 /* SCU */
88 node = of_find_compatible_node(NULL, NULL, scu_compatible);
89 if (!node) {
90 pr_err("Missing SCU node\n");
91 return;
92 }
93
94 scu_base = of_iomap(node, 0);
95 of_node_put(node);
96 if (!scu_base) {
97 pr_err("Couldn't map SCU registers\n");
98 return;
99 }
100
101 scu_enable(scu_base);
102 }
103
104 static void __init meson8b_smp_prepare_cpus(unsigned int max_cpus)
105 {
106 meson_smp_prepare_cpus("arm,cortex-a5-scu", "amlogic,meson8b-pmu",
107 "amlogic,meson8b-smp-sram");
108 }
109
110 static void __init meson8_smp_prepare_cpus(unsigned int max_cpus)
111 {
112 meson_smp_prepare_cpus("arm,cortex-a9-scu", "amlogic,meson8-pmu",
113 "amlogic,meson8-smp-sram");
114 }
115
116 static void meson_smp_begin_secondary_boot(unsigned int cpu)
117 {
118 /*
119 * Set the entry point before powering on the CPU through the SCU. This
120 * is needed if the CPU is in "warm" state (= after rebooting the
121 * system without power-cycling, or when taking the CPU offline and
122 * then taking it online again.
123 */
124 writel(__pa_symbol(secondary_startup),
125 sram_base + MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(cpu));
126
127 /*
128 * SCU Power on CPU (needs to be done before starting the CPU,
129 * otherwise the secondary CPU will not start).
130 */
131 scu_cpu_power_enable(scu_base, cpu);
132 }
133
134 static int meson_smp_finalize_secondary_boot(unsigned int cpu)
135 {
136 unsigned long timeout;
137
138 timeout = jiffies + (10 * HZ);
139 while (readl(sram_base + MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(cpu))) {
140 if (!time_before(jiffies, timeout)) {
141 pr_err("Timeout while waiting for CPU%d status\n",
142 cpu);
143 return -ETIMEDOUT;
144 }
145 }
146
147 writel(__pa_symbol(secondary_startup),
148 sram_base + MESON_SMP_SRAM_CPU_CTRL_ADDR_REG(cpu));
149
150 meson_smp_set_cpu_ctrl(cpu, true);
151
152 return 0;
153 }
154
155 static int meson8_smp_boot_secondary(unsigned int cpu,
156 struct task_struct *idle)
157 {
158 struct reset_control *rstc;
159 int ret;
160
161 rstc = meson_smp_get_core_reset(cpu);
162 if (IS_ERR(rstc)) {
163 pr_err("Couldn't get the reset controller for CPU%d\n", cpu);
164 return PTR_ERR(rstc);
165 }
166
167 meson_smp_begin_secondary_boot(cpu);
168
169 /* Reset enable */
170 ret = reset_control_assert(rstc);
171 if (ret) {
172 pr_err("Failed to assert CPU%d reset\n", cpu);
173 goto out;
174 }
175
176 /* CPU power ON */
177 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
178 MESON_CPU_PWR_A9_CNTL1_M(cpu), 0);
179 if (ret < 0) {
180 pr_err("Couldn't wake up CPU%d\n", cpu);
181 goto out;
182 }
183
184 udelay(10);
185
186 /* Isolation disable */
187 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
188 0);
189 if (ret < 0) {
190 pr_err("Error when disabling isolation of CPU%d\n", cpu);
191 goto out;
192 }
193
194 /* Reset disable */
195 ret = reset_control_deassert(rstc);
196 if (ret) {
197 pr_err("Failed to de-assert CPU%d reset\n", cpu);
198 goto out;
199 }
200
201 ret = meson_smp_finalize_secondary_boot(cpu);
202 if (ret)
203 goto out;
204
205 out:
206 reset_control_put(rstc);
207
208 return 0;
209 }
210
211 static int meson8b_smp_boot_secondary(unsigned int cpu,
212 struct task_struct *idle)
213 {
214 struct reset_control *rstc;
215 int ret;
216 u32 val;
217
218 rstc = meson_smp_get_core_reset(cpu);
219 if (IS_ERR(rstc)) {
220 pr_err("Couldn't get the reset controller for CPU%d\n", cpu);
221 return PTR_ERR(rstc);
222 }
223
224 meson_smp_begin_secondary_boot(cpu);
225
226 /* CPU power UP */
227 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0,
228 MESON_CPU_PWR_A9_CNTL0_M(cpu), 0);
229 if (ret < 0) {
230 pr_err("Couldn't power up CPU%d\n", cpu);
231 goto out;
232 }
233
234 udelay(5);
235
236 /* Reset enable */
237 ret = reset_control_assert(rstc);
238 if (ret) {
239 pr_err("Failed to assert CPU%d reset\n", cpu);
240 goto out;
241 }
242
243 /* Memory power UP */
244 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_MEM_PD0,
245 MESON_CPU_PWR_A9_MEM_PD0_M(cpu), 0);
246 if (ret < 0) {
247 pr_err("Couldn't power up the memory for CPU%d\n", cpu);
248 goto out;
249 }
250
251 /* Wake up CPU */
252 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
253 MESON_CPU_PWR_A9_CNTL1_M(cpu), 0);
254 if (ret < 0) {
255 pr_err("Couldn't wake up CPU%d\n", cpu);
256 goto out;
257 }
258
259 udelay(10);
260
261 ret = regmap_read_poll_timeout(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1, val,
262 val & MESON_CPU_PWR_A9_CNTL1_ST(cpu),
263 10, 10000);
264 if (ret) {
265 pr_err("Timeout while polling PMU for CPU%d status\n", cpu);
266 goto out;
267 }
268
269 /* Isolation disable */
270 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
271 0);
272 if (ret < 0) {
273 pr_err("Error when disabling isolation of CPU%d\n", cpu);
274 goto out;
275 }
276
277 /* Reset disable */
278 ret = reset_control_deassert(rstc);
279 if (ret) {
280 pr_err("Failed to de-assert CPU%d reset\n", cpu);
281 goto out;
282 }
283
284 ret = meson_smp_finalize_secondary_boot(cpu);
285 if (ret)
286 goto out;
287
288 out:
289 reset_control_put(rstc);
290
291 return 0;
292 }
293
294 #ifdef CONFIG_HOTPLUG_CPU
295 static void meson8_smp_cpu_die(unsigned int cpu)
296 {
297 meson_smp_set_cpu_ctrl(cpu, false);
298
299 v7_exit_coherency_flush(louis);
300
301 scu_power_mode(scu_base, SCU_PM_POWEROFF);
302
303 dsb();
304 wfi();
305
306 /* we should never get here */
307 WARN_ON(1);
308 }
309
310 static int meson8_smp_cpu_kill(unsigned int cpu)
311 {
312 int ret, power_mode;
313 unsigned long timeout;
314
315 timeout = jiffies + (50 * HZ);
316 do {
317 power_mode = scu_get_cpu_power_mode(scu_base, cpu);
318
319 if (power_mode == SCU_PM_POWEROFF)
320 break;
321
322 usleep_range(10000, 15000);
323 } while (time_before(jiffies, timeout));
324
325 if (power_mode != SCU_PM_POWEROFF) {
326 pr_err("Error while waiting for SCU power-off on CPU%d\n",
327 cpu);
328 return -ETIMEDOUT;
329 }
330
331 msleep(30);
332
333 /* Isolation enable */
334 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
335 0x3);
336 if (ret < 0) {
337 pr_err("Error when enabling isolation for CPU%d\n", cpu);
338 return ret;
339 }
340
341 udelay(10);
342
343 /* CPU power OFF */
344 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
345 MESON_CPU_PWR_A9_CNTL1_M(cpu), 0x3);
346 if (ret < 0) {
347 pr_err("Couldn't change sleep status of CPU%d\n", cpu);
348 return ret;
349 }
350
351 return 1;
352 }
353
354 static int meson8b_smp_cpu_kill(unsigned int cpu)
355 {
356 int ret, power_mode, count = 5000;
357
358 do {
359 power_mode = scu_get_cpu_power_mode(scu_base, cpu);
360
361 if (power_mode == SCU_PM_POWEROFF)
362 break;
363
364 udelay(10);
365 } while (++count);
366
367 if (power_mode != SCU_PM_POWEROFF) {
368 pr_err("Error while waiting for SCU power-off on CPU%d\n",
369 cpu);
370 return -ETIMEDOUT;
371 }
372
373 udelay(10);
374
375 /* CPU power DOWN */
376 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0,
377 MESON_CPU_PWR_A9_CNTL0_M(cpu), 0x3);
378 if (ret < 0) {
379 pr_err("Couldn't power down CPU%d\n", cpu);
380 return ret;
381 }
382
383 /* Isolation enable */
384 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL0, BIT(cpu),
385 0x3);
386 if (ret < 0) {
387 pr_err("Error when enabling isolation for CPU%d\n", cpu);
388 return ret;
389 }
390
391 udelay(10);
392
393 /* Sleep status */
394 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_CNTL1,
395 MESON_CPU_PWR_A9_CNTL1_M(cpu), 0x3);
396 if (ret < 0) {
397 pr_err("Couldn't change sleep status of CPU%d\n", cpu);
398 return ret;
399 }
400
401 /* Memory power DOWN */
402 ret = regmap_update_bits(pmu, MESON_CPU_AO_RTI_PWR_A9_MEM_PD0,
403 MESON_CPU_PWR_A9_MEM_PD0_M(cpu), 0xf);
404 if (ret < 0) {
405 pr_err("Couldn't power down the memory of CPU%d\n", cpu);
406 return ret;
407 }
408
409 return 1;
410 }
411 #endif
412
413 static struct smp_operations meson8_smp_ops __initdata = {
414 .smp_prepare_cpus = meson8_smp_prepare_cpus,
415 .smp_boot_secondary = meson8_smp_boot_secondary,
416 #ifdef CONFIG_HOTPLUG_CPU
417 .cpu_die = meson8_smp_cpu_die,
418 .cpu_kill = meson8_smp_cpu_kill,
419 #endif
420 };
421
422 static struct smp_operations meson8b_smp_ops __initdata = {
423 .smp_prepare_cpus = meson8b_smp_prepare_cpus,
424 .smp_boot_secondary = meson8b_smp_boot_secondary,
425 #ifdef CONFIG_HOTPLUG_CPU
426 .cpu_die = meson8_smp_cpu_die,
427 .cpu_kill = meson8b_smp_cpu_kill,
428 #endif
429 };
430
431 CPU_METHOD_OF_DECLARE(meson8_smp, "amlogic,meson8-smp", &meson8_smp_ops);
432 CPU_METHOD_OF_DECLARE(meson8b_smp, "amlogic,meson8b-smp", &meson8b_smp_ops);
433
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.