xref: /openbmc/linux/drivers/firmware/qcom_scm.c (revision 8730046c)
1 /*
2  * Qualcomm SCM driver
3  *
4  * Copyright (c) 2010,2015, The Linux Foundation. All rights reserved.
5  * Copyright (C) 2015 Linaro Ltd.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 and
9  * only version 2 as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  */
17 #include <linux/platform_device.h>
18 #include <linux/init.h>
19 #include <linux/cpumask.h>
20 #include <linux/export.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/types.h>
23 #include <linux/qcom_scm.h>
24 #include <linux/of.h>
25 #include <linux/of_platform.h>
26 #include <linux/clk.h>
27 #include <linux/reset-controller.h>
28 
29 #include "qcom_scm.h"
30 
31 #define SCM_HAS_CORE_CLK	BIT(0)
32 #define SCM_HAS_IFACE_CLK	BIT(1)
33 #define SCM_HAS_BUS_CLK		BIT(2)
34 
35 struct qcom_scm {
36 	struct device *dev;
37 	struct clk *core_clk;
38 	struct clk *iface_clk;
39 	struct clk *bus_clk;
40 	struct reset_controller_dev reset;
41 };
42 
43 static struct qcom_scm *__scm;
44 
45 static int qcom_scm_clk_enable(void)
46 {
47 	int ret;
48 
49 	ret = clk_prepare_enable(__scm->core_clk);
50 	if (ret)
51 		goto bail;
52 
53 	ret = clk_prepare_enable(__scm->iface_clk);
54 	if (ret)
55 		goto disable_core;
56 
57 	ret = clk_prepare_enable(__scm->bus_clk);
58 	if (ret)
59 		goto disable_iface;
60 
61 	return 0;
62 
63 disable_iface:
64 	clk_disable_unprepare(__scm->iface_clk);
65 disable_core:
66 	clk_disable_unprepare(__scm->core_clk);
67 bail:
68 	return ret;
69 }
70 
71 static void qcom_scm_clk_disable(void)
72 {
73 	clk_disable_unprepare(__scm->core_clk);
74 	clk_disable_unprepare(__scm->iface_clk);
75 	clk_disable_unprepare(__scm->bus_clk);
76 }
77 
78 /**
79  * qcom_scm_set_cold_boot_addr() - Set the cold boot address for cpus
80  * @entry: Entry point function for the cpus
81  * @cpus: The cpumask of cpus that will use the entry point
82  *
83  * Set the cold boot address of the cpus. Any cpu outside the supported
84  * range would be removed from the cpu present mask.
85  */
86 int qcom_scm_set_cold_boot_addr(void *entry, const cpumask_t *cpus)
87 {
88 	return __qcom_scm_set_cold_boot_addr(entry, cpus);
89 }
90 EXPORT_SYMBOL(qcom_scm_set_cold_boot_addr);
91 
92 /**
93  * qcom_scm_set_warm_boot_addr() - Set the warm boot address for cpus
94  * @entry: Entry point function for the cpus
95  * @cpus: The cpumask of cpus that will use the entry point
96  *
97  * Set the Linux entry point for the SCM to transfer control to when coming
98  * out of a power down. CPU power down may be executed on cpuidle or hotplug.
99  */
100 int qcom_scm_set_warm_boot_addr(void *entry, const cpumask_t *cpus)
101 {
102 	return __qcom_scm_set_warm_boot_addr(__scm->dev, entry, cpus);
103 }
104 EXPORT_SYMBOL(qcom_scm_set_warm_boot_addr);
105 
106 /**
107  * qcom_scm_cpu_power_down() - Power down the cpu
108  * @flags - Flags to flush cache
109  *
110  * This is an end point to power down cpu. If there was a pending interrupt,
111  * the control would return from this function, otherwise, the cpu jumps to the
112  * warm boot entry point set for this cpu upon reset.
113  */
114 void qcom_scm_cpu_power_down(u32 flags)
115 {
116 	__qcom_scm_cpu_power_down(flags);
117 }
118 EXPORT_SYMBOL(qcom_scm_cpu_power_down);
119 
120 /**
121  * qcom_scm_hdcp_available() - Check if secure environment supports HDCP.
122  *
123  * Return true if HDCP is supported, false if not.
124  */
125 bool qcom_scm_hdcp_available(void)
126 {
127 	int ret = qcom_scm_clk_enable();
128 
129 	if (ret)
130 		return ret;
131 
132 	ret = __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_HDCP,
133 						QCOM_SCM_CMD_HDCP);
134 
135 	qcom_scm_clk_disable();
136 
137 	return ret > 0 ? true : false;
138 }
139 EXPORT_SYMBOL(qcom_scm_hdcp_available);
140 
141 /**
142  * qcom_scm_hdcp_req() - Send HDCP request.
143  * @req: HDCP request array
144  * @req_cnt: HDCP request array count
145  * @resp: response buffer passed to SCM
146  *
147  * Write HDCP register(s) through SCM.
148  */
149 int qcom_scm_hdcp_req(struct qcom_scm_hdcp_req *req, u32 req_cnt, u32 *resp)
150 {
151 	int ret = qcom_scm_clk_enable();
152 
153 	if (ret)
154 		return ret;
155 
156 	ret = __qcom_scm_hdcp_req(__scm->dev, req, req_cnt, resp);
157 	qcom_scm_clk_disable();
158 	return ret;
159 }
160 EXPORT_SYMBOL(qcom_scm_hdcp_req);
161 
162 /**
163  * qcom_scm_pas_supported() - Check if the peripheral authentication service is
164  *			      available for the given peripherial
165  * @peripheral:	peripheral id
166  *
167  * Returns true if PAS is supported for this peripheral, otherwise false.
168  */
169 bool qcom_scm_pas_supported(u32 peripheral)
170 {
171 	int ret;
172 
173 	ret = __qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_PIL,
174 					   QCOM_SCM_PAS_IS_SUPPORTED_CMD);
175 	if (ret <= 0)
176 		return false;
177 
178 	return __qcom_scm_pas_supported(__scm->dev, peripheral);
179 }
180 EXPORT_SYMBOL(qcom_scm_pas_supported);
181 
182 /**
183  * qcom_scm_pas_init_image() - Initialize peripheral authentication service
184  *			       state machine for a given peripheral, using the
185  *			       metadata
186  * @peripheral: peripheral id
187  * @metadata:	pointer to memory containing ELF header, program header table
188  *		and optional blob of data used for authenticating the metadata
189  *		and the rest of the firmware
190  * @size:	size of the metadata
191  *
192  * Returns 0 on success.
193  */
194 int qcom_scm_pas_init_image(u32 peripheral, const void *metadata, size_t size)
195 {
196 	dma_addr_t mdata_phys;
197 	void *mdata_buf;
198 	int ret;
199 
200 	/*
201 	 * During the scm call memory protection will be enabled for the meta
202 	 * data blob, so make sure it's physically contiguous, 4K aligned and
203 	 * non-cachable to avoid XPU violations.
204 	 */
205 	mdata_buf = dma_alloc_coherent(__scm->dev, size, &mdata_phys,
206 				       GFP_KERNEL);
207 	if (!mdata_buf) {
208 		dev_err(__scm->dev, "Allocation of metadata buffer failed.\n");
209 		return -ENOMEM;
210 	}
211 	memcpy(mdata_buf, metadata, size);
212 
213 	ret = qcom_scm_clk_enable();
214 	if (ret)
215 		goto free_metadata;
216 
217 	ret = __qcom_scm_pas_init_image(__scm->dev, peripheral, mdata_phys);
218 
219 	qcom_scm_clk_disable();
220 
221 free_metadata:
222 	dma_free_coherent(__scm->dev, size, mdata_buf, mdata_phys);
223 
224 	return ret;
225 }
226 EXPORT_SYMBOL(qcom_scm_pas_init_image);
227 
228 /**
229  * qcom_scm_pas_mem_setup() - Prepare the memory related to a given peripheral
230  *			      for firmware loading
231  * @peripheral:	peripheral id
232  * @addr:	start address of memory area to prepare
233  * @size:	size of the memory area to prepare
234  *
235  * Returns 0 on success.
236  */
237 int qcom_scm_pas_mem_setup(u32 peripheral, phys_addr_t addr, phys_addr_t size)
238 {
239 	int ret;
240 
241 	ret = qcom_scm_clk_enable();
242 	if (ret)
243 		return ret;
244 
245 	ret = __qcom_scm_pas_mem_setup(__scm->dev, peripheral, addr, size);
246 	qcom_scm_clk_disable();
247 
248 	return ret;
249 }
250 EXPORT_SYMBOL(qcom_scm_pas_mem_setup);
251 
252 /**
253  * qcom_scm_pas_auth_and_reset() - Authenticate the given peripheral firmware
254  *				   and reset the remote processor
255  * @peripheral:	peripheral id
256  *
257  * Return 0 on success.
258  */
259 int qcom_scm_pas_auth_and_reset(u32 peripheral)
260 {
261 	int ret;
262 
263 	ret = qcom_scm_clk_enable();
264 	if (ret)
265 		return ret;
266 
267 	ret = __qcom_scm_pas_auth_and_reset(__scm->dev, peripheral);
268 	qcom_scm_clk_disable();
269 
270 	return ret;
271 }
272 EXPORT_SYMBOL(qcom_scm_pas_auth_and_reset);
273 
274 /**
275  * qcom_scm_pas_shutdown() - Shut down the remote processor
276  * @peripheral: peripheral id
277  *
278  * Returns 0 on success.
279  */
280 int qcom_scm_pas_shutdown(u32 peripheral)
281 {
282 	int ret;
283 
284 	ret = qcom_scm_clk_enable();
285 	if (ret)
286 		return ret;
287 
288 	ret = __qcom_scm_pas_shutdown(__scm->dev, peripheral);
289 	qcom_scm_clk_disable();
290 
291 	return ret;
292 }
293 EXPORT_SYMBOL(qcom_scm_pas_shutdown);
294 
295 static int qcom_scm_pas_reset_assert(struct reset_controller_dev *rcdev,
296 				     unsigned long idx)
297 {
298 	if (idx != 0)
299 		return -EINVAL;
300 
301 	return __qcom_scm_pas_mss_reset(__scm->dev, 1);
302 }
303 
304 static int qcom_scm_pas_reset_deassert(struct reset_controller_dev *rcdev,
305 				       unsigned long idx)
306 {
307 	if (idx != 0)
308 		return -EINVAL;
309 
310 	return __qcom_scm_pas_mss_reset(__scm->dev, 0);
311 }
312 
313 static const struct reset_control_ops qcom_scm_pas_reset_ops = {
314 	.assert = qcom_scm_pas_reset_assert,
315 	.deassert = qcom_scm_pas_reset_deassert,
316 };
317 
318 /**
319  * qcom_scm_is_available() - Checks if SCM is available
320  */
321 bool qcom_scm_is_available(void)
322 {
323 	return !!__scm;
324 }
325 EXPORT_SYMBOL(qcom_scm_is_available);
326 
327 static int qcom_scm_probe(struct platform_device *pdev)
328 {
329 	struct qcom_scm *scm;
330 	unsigned long clks;
331 	int ret;
332 
333 	scm = devm_kzalloc(&pdev->dev, sizeof(*scm), GFP_KERNEL);
334 	if (!scm)
335 		return -ENOMEM;
336 
337 	clks = (unsigned long)of_device_get_match_data(&pdev->dev);
338 	if (clks & SCM_HAS_CORE_CLK) {
339 		scm->core_clk = devm_clk_get(&pdev->dev, "core");
340 		if (IS_ERR(scm->core_clk)) {
341 			if (PTR_ERR(scm->core_clk) != -EPROBE_DEFER)
342 				dev_err(&pdev->dev,
343 					"failed to acquire core clk\n");
344 			return PTR_ERR(scm->core_clk);
345 		}
346 	}
347 
348 	if (clks & SCM_HAS_IFACE_CLK) {
349 		scm->iface_clk = devm_clk_get(&pdev->dev, "iface");
350 		if (IS_ERR(scm->iface_clk)) {
351 			if (PTR_ERR(scm->iface_clk) != -EPROBE_DEFER)
352 				dev_err(&pdev->dev,
353 					"failed to acquire iface clk\n");
354 			return PTR_ERR(scm->iface_clk);
355 		}
356 	}
357 
358 	if (clks & SCM_HAS_BUS_CLK) {
359 		scm->bus_clk = devm_clk_get(&pdev->dev, "bus");
360 		if (IS_ERR(scm->bus_clk)) {
361 			if (PTR_ERR(scm->bus_clk) != -EPROBE_DEFER)
362 				dev_err(&pdev->dev,
363 					"failed to acquire bus clk\n");
364 			return PTR_ERR(scm->bus_clk);
365 		}
366 	}
367 
368 	scm->reset.ops = &qcom_scm_pas_reset_ops;
369 	scm->reset.nr_resets = 1;
370 	scm->reset.of_node = pdev->dev.of_node;
371 	ret = devm_reset_controller_register(&pdev->dev, &scm->reset);
372 	if (ret)
373 		return ret;
374 
375 	/* vote for max clk rate for highest performance */
376 	ret = clk_set_rate(scm->core_clk, INT_MAX);
377 	if (ret)
378 		return ret;
379 
380 	__scm = scm;
381 	__scm->dev = &pdev->dev;
382 
383 	__qcom_scm_init();
384 
385 	return 0;
386 }
387 
388 static const struct of_device_id qcom_scm_dt_match[] = {
389 	{ .compatible = "qcom,scm-apq8064",
390 	  .data = (void *) SCM_HAS_CORE_CLK,
391 	},
392 	{ .compatible = "qcom,scm-msm8660",
393 	  .data = (void *) SCM_HAS_CORE_CLK,
394 	},
395 	{ .compatible = "qcom,scm-msm8960",
396 	  .data = (void *) SCM_HAS_CORE_CLK,
397 	},
398 	{ .compatible = "qcom,scm-msm8996",
399 	  .data = NULL, /* no clocks */
400 	},
401 	{ .compatible = "qcom,scm",
402 	  .data = (void *)(SCM_HAS_CORE_CLK
403 			   | SCM_HAS_IFACE_CLK
404 			   | SCM_HAS_BUS_CLK),
405 	},
406 	{}
407 };
408 
409 static struct platform_driver qcom_scm_driver = {
410 	.driver = {
411 		.name	= "qcom_scm",
412 		.of_match_table = qcom_scm_dt_match,
413 	},
414 	.probe = qcom_scm_probe,
415 };
416 
417 static int __init qcom_scm_init(void)
418 {
419 	struct device_node *np, *fw_np;
420 	int ret;
421 
422 	fw_np = of_find_node_by_name(NULL, "firmware");
423 
424 	if (!fw_np)
425 		return -ENODEV;
426 
427 	np = of_find_matching_node(fw_np, qcom_scm_dt_match);
428 
429 	if (!np) {
430 		of_node_put(fw_np);
431 		return -ENODEV;
432 	}
433 
434 	of_node_put(np);
435 
436 	ret = of_platform_populate(fw_np, qcom_scm_dt_match, NULL, NULL);
437 
438 	of_node_put(fw_np);
439 
440 	if (ret)
441 		return ret;
442 
443 	return platform_driver_register(&qcom_scm_driver);
444 }
445 subsys_initcall(qcom_scm_init);
446