1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2013 MundoReader S.L.
4 * Author: Heiko Stuebner <heiko@sntech.de>
5 */
6
7 #include <linux/delay.h>
8 #include <linux/init.h>
9 #include <linux/smp.h>
10 #include <linux/io.h>
11 #include <linux/of.h>
12 #include <linux/of_address.h>
13 #include <linux/regmap.h>
14 #include <linux/mfd/syscon.h>
15
16 #include <linux/reset.h>
17 #include <linux/cpu.h>
18 #include <asm/cacheflush.h>
19 #include <asm/cp15.h>
20 #include <asm/smp_scu.h>
21 #include <asm/smp_plat.h>
22 #include <asm/mach/map.h>
23
24 #include "core.h"
25
26 static void __iomem *scu_base_addr;
27 static void __iomem *sram_base_addr;
28 static int ncores;
29
30 #define PMU_PWRDN_CON 0x08
31 #define PMU_PWRDN_ST 0x0c
32
33 #define PMU_PWRDN_SCU 4
34
35 static struct regmap *pmu;
36 static int has_pmu = true;
37
pmu_power_domain_is_on(int pd)38 static int pmu_power_domain_is_on(int pd)
39 {
40 u32 val;
41 int ret;
42
43 ret = regmap_read(pmu, PMU_PWRDN_ST, &val);
44 if (ret < 0)
45 return ret;
46
47 return !(val & BIT(pd));
48 }
49
rockchip_get_core_reset(int cpu)50 static struct reset_control *rockchip_get_core_reset(int cpu)
51 {
52 struct device *dev = get_cpu_device(cpu);
53 struct device_node *np;
54
55 /* The cpu device is only available after the initial core bringup */
56 if (dev)
57 np = dev->of_node;
58 else
59 np = of_get_cpu_node(cpu, NULL);
60
61 return of_reset_control_get_exclusive(np, NULL);
62 }
63
pmu_set_power_domain(int pd,bool on)64 static int pmu_set_power_domain(int pd, bool on)
65 {
66 u32 val = (on) ? 0 : BIT(pd);
67 struct reset_control *rstc = rockchip_get_core_reset(pd);
68 int ret;
69
70 if (IS_ERR(rstc) && read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) {
71 pr_err("%s: could not get reset control for core %d\n",
72 __func__, pd);
73 return PTR_ERR(rstc);
74 }
75
76 /*
77 * We need to soft reset the cpu when we turn off the cpu power domain,
78 * or else the active processors might be stalled when the individual
79 * processor is powered down.
80 */
81 if (!IS_ERR(rstc) && !on)
82 reset_control_assert(rstc);
83
84 if (has_pmu) {
85 ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val);
86 if (ret < 0) {
87 pr_err("%s: could not update power domain\n",
88 __func__);
89 return ret;
90 }
91
92 ret = -1;
93 while (ret != on) {
94 ret = pmu_power_domain_is_on(pd);
95 if (ret < 0) {
96 pr_err("%s: could not read power domain state\n",
97 __func__);
98 return ret;
99 }
100 }
101 }
102
103 if (!IS_ERR(rstc)) {
104 if (on)
105 reset_control_deassert(rstc);
106 reset_control_put(rstc);
107 }
108
109 return 0;
110 }
111
112 /*
113 * Handling of CPU cores
114 */
115
rockchip_boot_secondary(unsigned int cpu,struct task_struct * idle)116 static int rockchip_boot_secondary(unsigned int cpu, struct task_struct *idle)
117 {
118 int ret;
119
120 if (!sram_base_addr || (has_pmu && !pmu)) {
121 pr_err("%s: sram or pmu missing for cpu boot\n", __func__);
122 return -ENXIO;
123 }
124
125 if (cpu >= ncores) {
126 pr_err("%s: cpu %d outside maximum number of cpus %d\n",
127 __func__, cpu, ncores);
128 return -ENXIO;
129 }
130
131 /* start the core */
132 ret = pmu_set_power_domain(0 + cpu, true);
133 if (ret < 0)
134 return ret;
135
136 if (read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) {
137 /*
138 * We communicate with the bootrom to active the cpus other
139 * than cpu0, after a blob of initialize code, they will
140 * stay at wfe state, once they are actived, they will check
141 * the mailbox:
142 * sram_base_addr + 4: 0xdeadbeaf
143 * sram_base_addr + 8: start address for pc
144 * The cpu0 need to wait the other cpus other than cpu0 entering
145 * the wfe state.The wait time is affected by many aspects.
146 * (e.g: cpu frequency, bootrom frequency, sram frequency, ...)
147 */
148 mdelay(1); /* ensure the cpus other than cpu0 to startup */
149
150 writel(__pa_symbol(secondary_startup), sram_base_addr + 8);
151 writel(0xDEADBEAF, sram_base_addr + 4);
152 dsb_sev();
153 }
154
155 return 0;
156 }
157
158 /**
159 * rockchip_smp_prepare_sram - populate necessary sram block
160 * Starting cores execute the code residing at the start of the on-chip sram
161 * after power-on. Therefore make sure, this sram region is reserved and
162 * big enough. After this check, copy the trampoline code that directs the
163 * core to the real startup code in ram into the sram-region.
164 * @node: mmio-sram device node
165 */
rockchip_smp_prepare_sram(struct device_node * node)166 static int __init rockchip_smp_prepare_sram(struct device_node *node)
167 {
168 unsigned int trampoline_sz = &rockchip_secondary_trampoline_end -
169 &rockchip_secondary_trampoline;
170 struct resource res;
171 unsigned int rsize;
172 int ret;
173
174 ret = of_address_to_resource(node, 0, &res);
175 if (ret < 0) {
176 pr_err("%s: could not get address for node %pOF\n",
177 __func__, node);
178 return ret;
179 }
180
181 rsize = resource_size(&res);
182 if (rsize < trampoline_sz) {
183 pr_err("%s: reserved block with size 0x%x is too small for trampoline size 0x%x\n",
184 __func__, rsize, trampoline_sz);
185 return -EINVAL;
186 }
187
188 /* set the boot function for the sram code */
189 rockchip_boot_fn = __pa_symbol(secondary_startup);
190
191 /* copy the trampoline to sram, that runs during startup of the core */
192 memcpy(sram_base_addr, &rockchip_secondary_trampoline, trampoline_sz);
193 flush_cache_all();
194 outer_clean_range(0, trampoline_sz);
195
196 dsb_sev();
197
198 return 0;
199 }
200
201 static const struct regmap_config rockchip_pmu_regmap_config = {
202 .name = "rockchip-pmu",
203 .reg_bits = 32,
204 .val_bits = 32,
205 .reg_stride = 4,
206 };
207
rockchip_smp_prepare_pmu(void)208 static int __init rockchip_smp_prepare_pmu(void)
209 {
210 struct device_node *node;
211 void __iomem *pmu_base;
212
213 /*
214 * This function is only called via smp_ops->smp_prepare_cpu().
215 * That only happens if a "/cpus" device tree node exists
216 * and has an "enable-method" property that selects the SMP
217 * operations defined herein.
218 */
219 node = of_find_node_by_path("/cpus");
220
221 pmu = syscon_regmap_lookup_by_phandle(node, "rockchip,pmu");
222 of_node_put(node);
223 if (!IS_ERR(pmu))
224 return 0;
225
226 pmu = syscon_regmap_lookup_by_compatible("rockchip,rk3066-pmu");
227 if (!IS_ERR(pmu))
228 return 0;
229
230 /* fallback, create our own regmap for the pmu area */
231 pmu = NULL;
232 node = of_find_compatible_node(NULL, NULL, "rockchip,rk3066-pmu");
233 if (!node) {
234 pr_err("%s: could not find pmu dt node\n", __func__);
235 return -ENODEV;
236 }
237
238 pmu_base = of_iomap(node, 0);
239 of_node_put(node);
240 if (!pmu_base) {
241 pr_err("%s: could not map pmu registers\n", __func__);
242 return -ENOMEM;
243 }
244
245 pmu = regmap_init_mmio(NULL, pmu_base, &rockchip_pmu_regmap_config);
246 if (IS_ERR(pmu)) {
247 int ret = PTR_ERR(pmu);
248
249 iounmap(pmu_base);
250 pmu = NULL;
251 pr_err("%s: regmap init failed\n", __func__);
252 return ret;
253 }
254
255 return 0;
256 }
257
rockchip_smp_prepare_cpus(unsigned int max_cpus)258 static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus)
259 {
260 struct device_node *node;
261 unsigned int i;
262
263 node = of_find_compatible_node(NULL, NULL, "rockchip,rk3066-smp-sram");
264 if (!node) {
265 pr_err("%s: could not find sram dt node\n", __func__);
266 return;
267 }
268
269 sram_base_addr = of_iomap(node, 0);
270 if (!sram_base_addr) {
271 pr_err("%s: could not map sram registers\n", __func__);
272 of_node_put(node);
273 return;
274 }
275
276 if (has_pmu && rockchip_smp_prepare_pmu()) {
277 of_node_put(node);
278 return;
279 }
280
281 if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
282 if (rockchip_smp_prepare_sram(node)) {
283 of_node_put(node);
284 return;
285 }
286
287 /* enable the SCU power domain */
288 pmu_set_power_domain(PMU_PWRDN_SCU, true);
289
290 of_node_put(node);
291 node = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
292 if (!node) {
293 pr_err("%s: missing scu\n", __func__);
294 return;
295 }
296
297 scu_base_addr = of_iomap(node, 0);
298 if (!scu_base_addr) {
299 pr_err("%s: could not map scu registers\n", __func__);
300 of_node_put(node);
301 return;
302 }
303
304 /*
305 * While the number of cpus is gathered from dt, also get the
306 * number of cores from the scu to verify this value when
307 * booting the cores.
308 */
309 ncores = scu_get_core_count(scu_base_addr);
310 pr_err("%s: ncores %d\n", __func__, ncores);
311
312 scu_enable(scu_base_addr);
313 } else {
314 unsigned int l2ctlr;
315
316 asm ("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr));
317 ncores = ((l2ctlr >> 24) & 0x3) + 1;
318 }
319 of_node_put(node);
320
321 /* Make sure that all cores except the first are really off */
322 for (i = 1; i < ncores; i++)
323 pmu_set_power_domain(0 + i, false);
324 }
325
rk3036_smp_prepare_cpus(unsigned int max_cpus)326 static void __init rk3036_smp_prepare_cpus(unsigned int max_cpus)
327 {
328 has_pmu = false;
329
330 rockchip_smp_prepare_cpus(max_cpus);
331 }
332
333 #ifdef CONFIG_HOTPLUG_CPU
rockchip_cpu_kill(unsigned int cpu)334 static int rockchip_cpu_kill(unsigned int cpu)
335 {
336 /*
337 * We need a delay here to ensure that the dying CPU can finish
338 * executing v7_coherency_exit() and reach the WFI/WFE state
339 * prior to having the power domain disabled.
340 */
341 mdelay(1);
342
343 pmu_set_power_domain(0 + cpu, false);
344 return 1;
345 }
346
rockchip_cpu_die(unsigned int cpu)347 static void rockchip_cpu_die(unsigned int cpu)
348 {
349 v7_exit_coherency_flush(louis);
350 while (1)
351 cpu_do_idle();
352 }
353 #endif
354
355 static const struct smp_operations rk3036_smp_ops __initconst = {
356 .smp_prepare_cpus = rk3036_smp_prepare_cpus,
357 .smp_boot_secondary = rockchip_boot_secondary,
358 #ifdef CONFIG_HOTPLUG_CPU
359 .cpu_kill = rockchip_cpu_kill,
360 .cpu_die = rockchip_cpu_die,
361 #endif
362 };
363
364 static const struct smp_operations rockchip_smp_ops __initconst = {
365 .smp_prepare_cpus = rockchip_smp_prepare_cpus,
366 .smp_boot_secondary = rockchip_boot_secondary,
367 #ifdef CONFIG_HOTPLUG_CPU
368 .cpu_kill = rockchip_cpu_kill,
369 .cpu_die = rockchip_cpu_die,
370 #endif
371 };
372
373 CPU_METHOD_OF_DECLARE(rk3036_smp, "rockchip,rk3036-smp", &rk3036_smp_ops);
374 CPU_METHOD_OF_DECLARE(rk3066_smp, "rockchip,rk3066-smp", &rockchip_smp_ops);
375