xref: /openbmc/linux/drivers/soc/ti/pm33xx.c (revision 1c6c0354)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * AM33XX Power Management Routines
4  *
5  * Copyright (C) 2012-2018 Texas Instruments Incorporated - http://www.ti.com/
6  *	Vaibhav Bedia, Dave Gerlach
7  */
8 
9 #include <linux/cpu.h>
10 #include <linux/err.h>
11 #include <linux/genalloc.h>
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/platform_data/pm33xx.h>
18 #include <linux/platform_device.h>
19 #include <linux/sizes.h>
20 #include <linux/sram.h>
21 #include <linux/suspend.h>
22 #include <linux/ti-emif-sram.h>
23 #include <linux/wkup_m3_ipc.h>
24 
25 #include <asm/proc-fns.h>
26 #include <asm/suspend.h>
27 #include <asm/system_misc.h>
28 
29 #define AMX3_PM_SRAM_SYMBOL_OFFSET(sym) ((unsigned long)(sym) - \
30 					 (unsigned long)pm_sram->do_wfi)
31 
32 static int (*am33xx_do_wfi_sram)(unsigned long unused);
33 static phys_addr_t am33xx_do_wfi_sram_phys;
34 
35 static struct gen_pool *sram_pool, *sram_pool_data;
36 static unsigned long ocmcram_location, ocmcram_location_data;
37 
38 static struct am33xx_pm_platform_data *pm_ops;
39 static struct am33xx_pm_sram_addr *pm_sram;
40 
41 static struct device *pm33xx_dev;
42 static struct wkup_m3_ipc *m3_ipc;
43 
44 static unsigned long suspend_wfi_flags;
45 
46 static u32 sram_suspend_address(unsigned long addr)
47 {
48 	return ((unsigned long)am33xx_do_wfi_sram +
49 		AMX3_PM_SRAM_SYMBOL_OFFSET(addr));
50 }
51 
52 static int am33xx_push_sram_idle(void)
53 {
54 	struct am33xx_pm_ro_sram_data ro_sram_data;
55 	int ret;
56 	u32 table_addr, ro_data_addr;
57 	void *copy_addr;
58 
59 	ro_sram_data.amx3_pm_sram_data_virt = ocmcram_location_data;
60 	ro_sram_data.amx3_pm_sram_data_phys =
61 		gen_pool_virt_to_phys(sram_pool_data, ocmcram_location_data);
62 	ro_sram_data.rtc_base_virt = pm_ops->get_rtc_base_addr();
63 
64 	/* Save physical address to calculate resume offset during pm init */
65 	am33xx_do_wfi_sram_phys = gen_pool_virt_to_phys(sram_pool,
66 							ocmcram_location);
67 
68 	am33xx_do_wfi_sram = sram_exec_copy(sram_pool, (void *)ocmcram_location,
69 					    pm_sram->do_wfi,
70 					    *pm_sram->do_wfi_sz);
71 	if (!am33xx_do_wfi_sram) {
72 		dev_err(pm33xx_dev,
73 			"PM: %s: am33xx_do_wfi copy to sram failed\n",
74 			__func__);
75 		return -ENODEV;
76 	}
77 
78 	table_addr =
79 		sram_suspend_address((unsigned long)pm_sram->emif_sram_table);
80 	ret = ti_emif_copy_pm_function_table(sram_pool, (void *)table_addr);
81 	if (ret) {
82 		dev_dbg(pm33xx_dev,
83 			"PM: %s: EMIF function copy failed\n", __func__);
84 		return -EPROBE_DEFER;
85 	}
86 
87 	ro_data_addr =
88 		sram_suspend_address((unsigned long)pm_sram->ro_sram_data);
89 	copy_addr = sram_exec_copy(sram_pool, (void *)ro_data_addr,
90 				   &ro_sram_data,
91 				   sizeof(ro_sram_data));
92 	if (!copy_addr) {
93 		dev_err(pm33xx_dev,
94 			"PM: %s: ro_sram_data copy to sram failed\n",
95 			__func__);
96 		return -ENODEV;
97 	}
98 
99 	return 0;
100 }
101 
102 #ifdef CONFIG_SUSPEND
103 static int am33xx_pm_suspend(suspend_state_t suspend_state)
104 {
105 	int i, ret = 0;
106 
107 	ret = pm_ops->soc_suspend((unsigned long)suspend_state,
108 				  am33xx_do_wfi_sram, suspend_wfi_flags);
109 
110 	if (ret) {
111 		dev_err(pm33xx_dev, "PM: Kernel suspend failure\n");
112 	} else {
113 		i = m3_ipc->ops->request_pm_status(m3_ipc);
114 
115 		switch (i) {
116 		case 0:
117 			dev_info(pm33xx_dev,
118 				 "PM: Successfully put all powerdomains to target state\n");
119 			break;
120 		case 1:
121 			dev_err(pm33xx_dev,
122 				"PM: Could not transition all powerdomains to target state\n");
123 			ret = -1;
124 			break;
125 		default:
126 			dev_err(pm33xx_dev,
127 				"PM: CM3 returned unknown result = %d\n", i);
128 			ret = -1;
129 		}
130 	}
131 
132 	return ret;
133 }
134 
135 static int am33xx_pm_enter(suspend_state_t suspend_state)
136 {
137 	int ret = 0;
138 
139 	switch (suspend_state) {
140 	case PM_SUSPEND_MEM:
141 	case PM_SUSPEND_STANDBY:
142 		ret = am33xx_pm_suspend(suspend_state);
143 		break;
144 	default:
145 		ret = -EINVAL;
146 	}
147 
148 	return ret;
149 }
150 
151 static int am33xx_pm_begin(suspend_state_t state)
152 {
153 	int ret = -EINVAL;
154 
155 	switch (state) {
156 	case PM_SUSPEND_MEM:
157 		ret = m3_ipc->ops->prepare_low_power(m3_ipc, WKUP_M3_DEEPSLEEP);
158 		break;
159 	case PM_SUSPEND_STANDBY:
160 		ret = m3_ipc->ops->prepare_low_power(m3_ipc, WKUP_M3_STANDBY);
161 		break;
162 	}
163 
164 	return ret;
165 }
166 
167 static void am33xx_pm_end(void)
168 {
169 	m3_ipc->ops->finish_low_power(m3_ipc);
170 }
171 
172 static int am33xx_pm_valid(suspend_state_t state)
173 {
174 	switch (state) {
175 	case PM_SUSPEND_STANDBY:
176 	case PM_SUSPEND_MEM:
177 		return 1;
178 	default:
179 		return 0;
180 	}
181 }
182 
183 static const struct platform_suspend_ops am33xx_pm_ops = {
184 	.begin		= am33xx_pm_begin,
185 	.end		= am33xx_pm_end,
186 	.enter		= am33xx_pm_enter,
187 	.valid		= am33xx_pm_valid,
188 };
189 #endif /* CONFIG_SUSPEND */
190 
191 static void am33xx_pm_set_ipc_ops(void)
192 {
193 	u32 resume_address;
194 	int temp;
195 
196 	temp = ti_emif_get_mem_type();
197 	if (temp < 0) {
198 		dev_err(pm33xx_dev, "PM: Cannot determine memory type, no PM available\n");
199 		return;
200 	}
201 	m3_ipc->ops->set_mem_type(m3_ipc, temp);
202 
203 	/* Physical resume address to be used by ROM code */
204 	resume_address = am33xx_do_wfi_sram_phys +
205 			 *pm_sram->resume_offset + 0x4;
206 
207 	m3_ipc->ops->set_resume_address(m3_ipc, (void *)resume_address);
208 }
209 
210 static void am33xx_pm_free_sram(void)
211 {
212 	gen_pool_free(sram_pool, ocmcram_location, *pm_sram->do_wfi_sz);
213 	gen_pool_free(sram_pool_data, ocmcram_location_data,
214 		      sizeof(struct am33xx_pm_ro_sram_data));
215 }
216 
217 /*
218  * Push the minimal suspend-resume code to SRAM
219  */
220 static int am33xx_pm_alloc_sram(void)
221 {
222 	struct device_node *np;
223 	int ret = 0;
224 
225 	np = of_find_compatible_node(NULL, NULL, "ti,omap3-mpu");
226 	if (!np) {
227 		np = of_find_compatible_node(NULL, NULL, "ti,omap4-mpu");
228 		if (!np) {
229 			dev_err(pm33xx_dev, "PM: %s: Unable to find device node for mpu\n",
230 				__func__);
231 			return -ENODEV;
232 		}
233 	}
234 
235 	sram_pool = of_gen_pool_get(np, "pm-sram", 0);
236 	if (!sram_pool) {
237 		dev_err(pm33xx_dev, "PM: %s: Unable to get sram pool for ocmcram\n",
238 			__func__);
239 		ret = -ENODEV;
240 		goto mpu_put_node;
241 	}
242 
243 	sram_pool_data = of_gen_pool_get(np, "pm-sram", 1);
244 	if (!sram_pool_data) {
245 		dev_err(pm33xx_dev, "PM: %s: Unable to get sram data pool for ocmcram\n",
246 			__func__);
247 		ret = -ENODEV;
248 		goto mpu_put_node;
249 	}
250 
251 	ocmcram_location = gen_pool_alloc(sram_pool, *pm_sram->do_wfi_sz);
252 	if (!ocmcram_location) {
253 		dev_err(pm33xx_dev, "PM: %s: Unable to allocate memory from ocmcram\n",
254 			__func__);
255 		ret = -ENOMEM;
256 		goto mpu_put_node;
257 	}
258 
259 	ocmcram_location_data = gen_pool_alloc(sram_pool_data,
260 					       sizeof(struct emif_regs_amx3));
261 	if (!ocmcram_location_data) {
262 		dev_err(pm33xx_dev, "PM: Unable to allocate memory from ocmcram\n");
263 		gen_pool_free(sram_pool, ocmcram_location, *pm_sram->do_wfi_sz);
264 		ret = -ENOMEM;
265 	}
266 
267 mpu_put_node:
268 	of_node_put(np);
269 	return ret;
270 }
271 
272 static int am33xx_pm_probe(struct platform_device *pdev)
273 {
274 	struct device *dev = &pdev->dev;
275 	int ret;
276 
277 	if (!of_machine_is_compatible("ti,am33xx") &&
278 	    !of_machine_is_compatible("ti,am43"))
279 		return -ENODEV;
280 
281 	pm_ops = dev->platform_data;
282 	if (!pm_ops) {
283 		dev_err(dev, "PM: Cannot get core PM ops!\n");
284 		return -ENODEV;
285 	}
286 
287 	pm_sram = pm_ops->get_sram_addrs();
288 	if (!pm_sram) {
289 		dev_err(dev, "PM: Cannot get PM asm function addresses!!\n");
290 		return -ENODEV;
291 	}
292 
293 	pm33xx_dev = dev;
294 
295 	ret = am33xx_pm_alloc_sram();
296 	if (ret)
297 		return ret;
298 
299 	ret = am33xx_push_sram_idle();
300 	if (ret)
301 		goto err_free_sram;
302 
303 	m3_ipc = wkup_m3_ipc_get();
304 	if (!m3_ipc) {
305 		dev_dbg(dev, "PM: Cannot get wkup_m3_ipc handle\n");
306 		ret = -EPROBE_DEFER;
307 		goto err_free_sram;
308 	}
309 
310 	am33xx_pm_set_ipc_ops();
311 
312 #ifdef CONFIG_SUSPEND
313 	suspend_set_ops(&am33xx_pm_ops);
314 #endif /* CONFIG_SUSPEND */
315 
316 	/*
317 	 * For a system suspend we must flush the caches, we want
318 	 * the DDR in self-refresh, we want to save the context
319 	 * of the EMIF, and we want the wkup_m3 to handle low-power
320 	 * transition.
321 	 */
322 	suspend_wfi_flags |= WFI_FLAG_FLUSH_CACHE;
323 	suspend_wfi_flags |= WFI_FLAG_SELF_REFRESH;
324 	suspend_wfi_flags |= WFI_FLAG_SAVE_EMIF;
325 	suspend_wfi_flags |= WFI_FLAG_WAKE_M3;
326 
327 	ret = pm_ops->init();
328 	if (ret) {
329 		dev_err(dev, "Unable to call core pm init!\n");
330 		ret = -ENODEV;
331 		goto err_put_wkup_m3_ipc;
332 	}
333 
334 	return 0;
335 
336 err_put_wkup_m3_ipc:
337 	wkup_m3_ipc_put(m3_ipc);
338 err_free_sram:
339 	am33xx_pm_free_sram();
340 	pm33xx_dev = NULL;
341 	return ret;
342 }
343 
344 static int am33xx_pm_remove(struct platform_device *pdev)
345 {
346 	suspend_set_ops(NULL);
347 	wkup_m3_ipc_put(m3_ipc);
348 	am33xx_pm_free_sram();
349 	return 0;
350 }
351 
352 static struct platform_driver am33xx_pm_driver = {
353 	.driver = {
354 		.name   = "pm33xx",
355 	},
356 	.probe = am33xx_pm_probe,
357 	.remove = am33xx_pm_remove,
358 };
359 module_platform_driver(am33xx_pm_driver);
360 
361 MODULE_ALIAS("platform:pm33xx");
362 MODULE_LICENSE("GPL v2");
363 MODULE_DESCRIPTION("am33xx power management driver");
364