xref: /linux/drivers/net/ipa/ipa_power.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
4  * Copyright (C) 2018-2022 Linaro Ltd.
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/device.h>
9 #include <linux/interconnect.h>
10 #include <linux/pm.h>
11 #include <linux/pm_runtime.h>
12 #include <linux/bitops.h>
13 
14 #include "linux/soc/qcom/qcom_aoss.h"
15 
16 #include "ipa.h"
17 #include "ipa_power.h"
18 #include "ipa_endpoint.h"
19 #include "ipa_modem.h"
20 #include "ipa_data.h"
21 
22 /**
23  * DOC: IPA Power Management
24  *
25  * The IPA hardware is enabled when the IPA core clock and all the
26  * interconnects (buses) it depends on are enabled.  Runtime power
27  * management is used to determine whether the core clock and
28  * interconnects are enabled, and if not in use to be suspended
29  * automatically.
30  *
31  * The core clock currently runs at a fixed clock rate when enabled,
32  * an all interconnects use a fixed average and peak bandwidth.
33  */
34 
35 #define IPA_AUTOSUSPEND_DELAY	500	/* milliseconds */
36 
37 /**
38  * struct ipa_power - IPA power management information
39  * @dev:		IPA device pointer
40  * @core:		IPA core clock
41  * @qmp:		QMP handle for AOSS communication
42  * @interconnect_count:	Number of elements in interconnect[]
43  * @interconnect:	Interconnect array
44  */
45 struct ipa_power {
46 	struct device *dev;
47 	struct clk *core;
48 	struct qmp *qmp;
49 	u32 interconnect_count;
50 	struct icc_bulk_data interconnect[] __counted_by(interconnect_count);
51 };
52 
53 /* Initialize interconnects required for IPA operation */
54 static int ipa_interconnect_init(struct ipa_power *power,
55 				 const struct ipa_interconnect_data *data)
56 {
57 	struct icc_bulk_data *interconnect;
58 	int ret;
59 	u32 i;
60 
61 	/* Initialize our interconnect data array for bulk operations */
62 	interconnect = &power->interconnect[0];
63 	for (i = 0; i < power->interconnect_count; i++) {
64 		/* interconnect->path is filled in by of_icc_bulk_get() */
65 		interconnect->name = data->name;
66 		interconnect->avg_bw = data->average_bandwidth;
67 		interconnect->peak_bw = data->peak_bandwidth;
68 		data++;
69 		interconnect++;
70 	}
71 
72 	ret = of_icc_bulk_get(power->dev, power->interconnect_count,
73 			      power->interconnect);
74 	if (ret)
75 		return ret;
76 
77 	/* All interconnects are initially disabled */
78 	icc_bulk_disable(power->interconnect_count, power->interconnect);
79 
80 	/* Set the bandwidth values to be used when enabled */
81 	ret = icc_bulk_set_bw(power->interconnect_count, power->interconnect);
82 	if (ret)
83 		icc_bulk_put(power->interconnect_count, power->interconnect);
84 
85 	return ret;
86 }
87 
88 /* Inverse of ipa_interconnect_init() */
89 static void ipa_interconnect_exit(struct ipa_power *power)
90 {
91 	icc_bulk_put(power->interconnect_count, power->interconnect);
92 }
93 
94 /* Enable IPA power, enabling interconnects and the core clock */
95 static int ipa_power_enable(struct ipa *ipa)
96 {
97 	struct ipa_power *power = ipa->power;
98 	int ret;
99 
100 	ret = icc_bulk_enable(power->interconnect_count, power->interconnect);
101 	if (ret)
102 		return ret;
103 
104 	ret = clk_prepare_enable(power->core);
105 	if (ret) {
106 		dev_err(power->dev, "error %d enabling core clock\n", ret);
107 		icc_bulk_disable(power->interconnect_count,
108 				 power->interconnect);
109 	}
110 
111 	return ret;
112 }
113 
114 /* Inverse of ipa_power_enable() */
115 static void ipa_power_disable(struct ipa *ipa)
116 {
117 	struct ipa_power *power = ipa->power;
118 
119 	clk_disable_unprepare(power->core);
120 
121 	icc_bulk_disable(power->interconnect_count, power->interconnect);
122 }
123 
124 static int ipa_runtime_suspend(struct device *dev)
125 {
126 	struct ipa *ipa = dev_get_drvdata(dev);
127 
128 	/* Endpoints aren't usable until setup is complete */
129 	if (ipa->setup_complete) {
130 		ipa_endpoint_suspend(ipa);
131 		gsi_suspend(&ipa->gsi);
132 	}
133 
134 	ipa_power_disable(ipa);
135 
136 	return 0;
137 }
138 
139 static int ipa_runtime_resume(struct device *dev)
140 {
141 	struct ipa *ipa = dev_get_drvdata(dev);
142 	int ret;
143 
144 	ret = ipa_power_enable(ipa);
145 	if (WARN_ON(ret < 0))
146 		return ret;
147 
148 	/* Endpoints aren't usable until setup is complete */
149 	if (ipa->setup_complete) {
150 		gsi_resume(&ipa->gsi);
151 		ipa_endpoint_resume(ipa);
152 	}
153 
154 	return 0;
155 }
156 
157 static int ipa_suspend(struct device *dev)
158 {
159 	struct ipa *ipa = dev_get_drvdata(dev);
160 
161 	/* Increment the disable depth to ensure that the IRQ won't
162 	 * be re-enabled until the matching _enable call in
163 	 * ipa_resume(). We do this to ensure that the interrupt
164 	 * handler won't run whilst PM runtime is disabled.
165 	 *
166 	 * Note that disabling the IRQ is NOT the same as disabling
167 	 * irq wake. If wakeup is enabled for the IPA then the IRQ
168 	 * will still cause the system to wake up, see irq_set_irq_wake().
169 	 */
170 	ipa_interrupt_irq_disable(ipa);
171 
172 	return pm_runtime_force_suspend(dev);
173 }
174 
175 static int ipa_resume(struct device *dev)
176 {
177 	struct ipa *ipa = dev_get_drvdata(dev);
178 	int ret;
179 
180 	ret = pm_runtime_force_resume(dev);
181 
182 	/* Now that PM runtime is enabled again it's safe
183 	 * to turn the IRQ back on and process any data
184 	 * that was received during suspend.
185 	 */
186 	ipa_interrupt_irq_enable(ipa);
187 
188 	return ret;
189 }
190 
191 /* Return the current IPA core clock rate */
192 u32 ipa_core_clock_rate(struct ipa *ipa)
193 {
194 	return ipa->power ? (u32)clk_get_rate(ipa->power->core) : 0;
195 }
196 
197 static int ipa_power_retention_init(struct ipa_power *power)
198 {
199 	struct qmp *qmp = qmp_get(power->dev);
200 
201 	if (IS_ERR(qmp)) {
202 		if (PTR_ERR(qmp) == -EPROBE_DEFER)
203 			return -EPROBE_DEFER;
204 
205 		/* We assume any other error means it's not defined/needed */
206 		qmp = NULL;
207 	}
208 	power->qmp = qmp;
209 
210 	return 0;
211 }
212 
213 static void ipa_power_retention_exit(struct ipa_power *power)
214 {
215 	qmp_put(power->qmp);
216 	power->qmp = NULL;
217 }
218 
219 /* Control register retention on power collapse */
220 void ipa_power_retention(struct ipa *ipa, bool enable)
221 {
222 	static const char fmt[] = "{ class: bcm, res: ipa_pc, val: %c }";
223 	struct ipa_power *power = ipa->power;
224 	int ret;
225 
226 	if (!power->qmp)
227 		return;		/* Not needed on this platform */
228 
229 	ret = qmp_send(power->qmp, fmt, enable ? '1' : '0');
230 	if (ret)
231 		dev_err(power->dev, "error %d sending QMP %sable request\n",
232 			ret, enable ? "en" : "dis");
233 }
234 
235 int ipa_power_setup(struct ipa *ipa)
236 {
237 	int ret;
238 
239 	ipa_interrupt_enable(ipa, IPA_IRQ_TX_SUSPEND);
240 
241 	ret = device_init_wakeup(ipa->dev, true);
242 	if (ret)
243 		ipa_interrupt_disable(ipa, IPA_IRQ_TX_SUSPEND);
244 
245 	return ret;
246 }
247 
248 void ipa_power_teardown(struct ipa *ipa)
249 {
250 	(void)device_init_wakeup(ipa->dev, false);
251 	ipa_interrupt_disable(ipa, IPA_IRQ_TX_SUSPEND);
252 }
253 
254 /* Initialize IPA power management */
255 struct ipa_power *
256 ipa_power_init(struct device *dev, const struct ipa_power_data *data)
257 {
258 	struct ipa_power *power;
259 	struct clk *clk;
260 	size_t size;
261 	int ret;
262 
263 	clk = clk_get(dev, "core");
264 	if (IS_ERR(clk)) {
265 		dev_err_probe(dev, PTR_ERR(clk), "error getting core clock\n");
266 
267 		return ERR_CAST(clk);
268 	}
269 
270 	ret = clk_set_rate(clk, data->core_clock_rate);
271 	if (ret) {
272 		dev_err(dev, "error %d setting core clock rate to %u\n",
273 			ret, data->core_clock_rate);
274 		goto err_clk_put;
275 	}
276 
277 	size = struct_size(power, interconnect, data->interconnect_count);
278 	power = kzalloc(size, GFP_KERNEL);
279 	if (!power) {
280 		ret = -ENOMEM;
281 		goto err_clk_put;
282 	}
283 	power->dev = dev;
284 	power->core = clk;
285 	power->interconnect_count = data->interconnect_count;
286 
287 	ret = ipa_interconnect_init(power, data->interconnect_data);
288 	if (ret)
289 		goto err_kfree;
290 
291 	ret = ipa_power_retention_init(power);
292 	if (ret)
293 		goto err_interconnect_exit;
294 
295 	pm_runtime_set_autosuspend_delay(dev, IPA_AUTOSUSPEND_DELAY);
296 	pm_runtime_use_autosuspend(dev);
297 	pm_runtime_enable(dev);
298 
299 	return power;
300 
301 err_interconnect_exit:
302 	ipa_interconnect_exit(power);
303 err_kfree:
304 	kfree(power);
305 err_clk_put:
306 	clk_put(clk);
307 
308 	return ERR_PTR(ret);
309 }
310 
311 /* Inverse of ipa_power_init() */
312 void ipa_power_exit(struct ipa_power *power)
313 {
314 	struct device *dev = power->dev;
315 	struct clk *clk = power->core;
316 
317 	pm_runtime_disable(dev);
318 	pm_runtime_dont_use_autosuspend(dev);
319 	ipa_power_retention_exit(power);
320 	ipa_interconnect_exit(power);
321 	kfree(power);
322 	clk_put(clk);
323 }
324 
325 const struct dev_pm_ops ipa_pm_ops = {
326 	.suspend		= ipa_suspend,
327 	.resume			= ipa_resume,
328 	.runtime_suspend	= ipa_runtime_suspend,
329 	.runtime_resume		= ipa_runtime_resume,
330 };
331