1 // SPDX-License-Identifier: GPL-2.0
3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
4 * Copyright (C) 2018-2021 Linaro Ltd.
8 #include <linux/device.h>
9 #include <linux/interconnect.h>
11 #include <linux/pm_runtime.h>
12 #include <linux/bitops.h>
14 #include "linux/soc/qcom/qcom_aoss.h"
17 #include "ipa_power.h"
18 #include "ipa_endpoint.h"
19 #include "ipa_modem.h"
23 * DOC: IPA Power Management
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
31 * The core clock currently runs at a fixed clock rate when enabled,
32 * an all interconnects use a fixed average and peak bandwidth.
35 #define IPA_AUTOSUSPEND_DELAY 500 /* milliseconds */
38 * enum ipa_power_flag - IPA power flags
39 * @IPA_POWER_FLAG_RESUMED: Whether resume from suspend has been signaled
40 * @IPA_POWER_FLAG_SYSTEM: Hardware is system (not runtime) suspended
41 * @IPA_POWER_FLAG_STOPPED: Modem TX is disabled by ipa_start_xmit()
42 * @IPA_POWER_FLAG_STARTED: Modem TX was enabled by ipa_runtime_resume()
43 * @IPA_POWER_FLAG_COUNT: Number of defined power flags
46 IPA_POWER_FLAG_RESUMED,
47 IPA_POWER_FLAG_SYSTEM,
48 IPA_POWER_FLAG_STOPPED,
49 IPA_POWER_FLAG_STARTED,
50 IPA_POWER_FLAG_COUNT, /* Last; not a flag */
54 * struct ipa_power - IPA power management information
55 * @dev: IPA device pointer
56 * @core: IPA core clock
57 * @qmp: QMP handle for AOSS communication
58 * @spinlock: Protects modem TX queue enable/disable
59 * @flags: Boolean state flags
60 * @interconnect_count: Number of elements in interconnect[]
61 * @interconnect: Interconnect array
67 spinlock_t spinlock; /* used with STOPPED/STARTED power flags */
68 DECLARE_BITMAP(flags, IPA_POWER_FLAG_COUNT);
69 u32 interconnect_count;
70 struct icc_bulk_data interconnect[];
73 /* Initialize interconnects required for IPA operation */
74 static int ipa_interconnect_init(struct ipa_power *power,
75 const struct ipa_interconnect_data *data)
77 struct icc_bulk_data *interconnect;
81 /* Initialize our interconnect data array for bulk operations */
82 interconnect = &power->interconnect[0];
83 for (i = 0; i < power->interconnect_count; i++) {
84 /* interconnect->path is filled in by of_icc_bulk_get() */
85 interconnect->name = data->name;
86 interconnect->avg_bw = data->average_bandwidth;
87 interconnect->peak_bw = data->peak_bandwidth;
92 ret = of_icc_bulk_get(power->dev, power->interconnect_count,
97 /* All interconnects are initially disabled */
98 icc_bulk_disable(power->interconnect_count, power->interconnect);
100 /* Set the bandwidth values to be used when enabled */
101 ret = icc_bulk_set_bw(power->interconnect_count, power->interconnect);
103 icc_bulk_put(power->interconnect_count, power->interconnect);
108 /* Inverse of ipa_interconnect_init() */
109 static void ipa_interconnect_exit(struct ipa_power *power)
111 icc_bulk_put(power->interconnect_count, power->interconnect);
114 /* Enable IPA power, enabling interconnects and the core clock */
115 static int ipa_power_enable(struct ipa *ipa)
117 struct ipa_power *power = ipa->power;
120 ret = icc_bulk_enable(power->interconnect_count, power->interconnect);
124 ret = clk_prepare_enable(power->core);
126 dev_err(power->dev, "error %d enabling core clock\n", ret);
127 icc_bulk_disable(power->interconnect_count,
128 power->interconnect);
134 /* Inverse of ipa_power_enable() */
135 static void ipa_power_disable(struct ipa *ipa)
137 struct ipa_power *power = ipa->power;
139 clk_disable_unprepare(power->core);
141 icc_bulk_disable(power->interconnect_count, power->interconnect);
144 static int ipa_runtime_suspend(struct device *dev)
146 struct ipa *ipa = dev_get_drvdata(dev);
148 /* Endpoints aren't usable until setup is complete */
149 if (ipa->setup_complete) {
150 __clear_bit(IPA_POWER_FLAG_RESUMED, ipa->power->flags);
151 ipa_endpoint_suspend(ipa);
152 gsi_suspend(&ipa->gsi);
155 ipa_power_disable(ipa);
160 static int ipa_runtime_resume(struct device *dev)
162 struct ipa *ipa = dev_get_drvdata(dev);
165 ret = ipa_power_enable(ipa);
166 if (WARN_ON(ret < 0))
169 /* Endpoints aren't usable until setup is complete */
170 if (ipa->setup_complete) {
171 gsi_resume(&ipa->gsi);
172 ipa_endpoint_resume(ipa);
178 static int ipa_suspend(struct device *dev)
180 struct ipa *ipa = dev_get_drvdata(dev);
182 __set_bit(IPA_POWER_FLAG_SYSTEM, ipa->power->flags);
184 return pm_runtime_force_suspend(dev);
187 static int ipa_resume(struct device *dev)
189 struct ipa *ipa = dev_get_drvdata(dev);
192 ret = pm_runtime_force_resume(dev);
194 __clear_bit(IPA_POWER_FLAG_SYSTEM, ipa->power->flags);
199 /* Return the current IPA core clock rate */
200 u32 ipa_core_clock_rate(struct ipa *ipa)
202 return ipa->power ? (u32)clk_get_rate(ipa->power->core) : 0;
206 * ipa_suspend_handler() - Handle the suspend IPA interrupt
208 * @irq_id: IPA interrupt type (unused)
210 * If an RX endpoint is suspended, and the IPA has a packet destined for
211 * that endpoint, the IPA generates a SUSPEND interrupt to inform the AP
212 * that it should resume the endpoint. If we get one of these interrupts
213 * we just wake up the system.
215 static void ipa_suspend_handler(struct ipa *ipa, enum ipa_irq_id irq_id)
217 /* To handle an IPA interrupt we will have resumed the hardware
218 * just to handle the interrupt, so we're done. If we are in a
219 * system suspend, trigger a system resume.
221 if (!__test_and_set_bit(IPA_POWER_FLAG_RESUMED, ipa->power->flags))
222 if (test_bit(IPA_POWER_FLAG_SYSTEM, ipa->power->flags))
223 pm_wakeup_dev_event(&ipa->pdev->dev, 0, true);
225 /* Acknowledge/clear the suspend interrupt on all endpoints */
226 ipa_interrupt_suspend_clear_all(ipa->interrupt);
229 /* The next few functions coordinate stopping and starting the modem
230 * network device transmit queue.
232 * Transmit can be running concurrent with power resume, and there's a
233 * chance the resume completes before the transmit path stops the queue,
234 * leaving the queue in a stopped state. The next two functions are used
235 * to avoid this: ipa_power_modem_queue_stop() is used by ipa_start_xmit()
236 * to conditionally stop the TX queue; and ipa_power_modem_queue_start()
237 * is used by ipa_runtime_resume() to conditionally restart it.
239 * Two flags and a spinlock are used. If the queue is stopped, the STOPPED
240 * power flag is set. And if the queue is started, the STARTED flag is set.
241 * The queue is only started on resume if the STOPPED flag is set. And the
242 * queue is only started in ipa_start_xmit() if the STARTED flag is *not*
243 * set. As a result, the queue remains operational if the two activites
244 * happen concurrently regardless of the order they complete. The spinlock
245 * ensures the flag and TX queue operations are done atomically.
247 * The first function stops the modem netdev transmit queue, but only if
248 * the STARTED flag is *not* set. That flag is cleared if it was set.
249 * If the queue is stopped, the STOPPED flag is set. This is called only
250 * from the power ->runtime_resume operation.
252 void ipa_power_modem_queue_stop(struct ipa *ipa)
254 struct ipa_power *power = ipa->power;
257 spin_lock_irqsave(&power->spinlock, flags);
259 if (!__test_and_clear_bit(IPA_POWER_FLAG_STARTED, power->flags)) {
260 netif_stop_queue(ipa->modem_netdev);
261 __set_bit(IPA_POWER_FLAG_STOPPED, power->flags);
264 spin_unlock_irqrestore(&power->spinlock, flags);
267 /* This function starts the modem netdev transmit queue, but only if the
268 * STOPPED flag is set. That flag is cleared if it was set. If the queue
269 * was restarted, the STARTED flag is set; this allows ipa_start_xmit()
270 * to skip stopping the queue in the event of a race.
272 void ipa_power_modem_queue_wake(struct ipa *ipa)
274 struct ipa_power *power = ipa->power;
277 spin_lock_irqsave(&power->spinlock, flags);
279 if (__test_and_clear_bit(IPA_POWER_FLAG_STOPPED, power->flags)) {
280 __set_bit(IPA_POWER_FLAG_STARTED, power->flags);
281 netif_wake_queue(ipa->modem_netdev);
284 spin_unlock_irqrestore(&power->spinlock, flags);
287 /* This function clears the STARTED flag once the TX queue is operating */
288 void ipa_power_modem_queue_active(struct ipa *ipa)
290 clear_bit(IPA_POWER_FLAG_STARTED, ipa->power->flags);
293 static int ipa_power_retention_init(struct ipa_power *power)
295 struct qmp *qmp = qmp_get(power->dev);
298 if (PTR_ERR(qmp) == -EPROBE_DEFER)
299 return -EPROBE_DEFER;
301 /* We assume any other error means it's not defined/needed */
309 static void ipa_power_retention_exit(struct ipa_power *power)
315 /* Control register retention on power collapse */
316 void ipa_power_retention(struct ipa *ipa, bool enable)
318 static const char fmt[] = "{ class: bcm, res: ipa_pc, val: %c }";
319 struct ipa_power *power = ipa->power;
320 char buf[36]; /* Exactly enough for fmt[]; size a multiple of 4 */
324 return; /* Not needed on this platform */
326 (void)snprintf(buf, sizeof(buf), fmt, enable ? '1' : '0');
328 ret = qmp_send(power->qmp, buf, sizeof(buf));
330 dev_err(power->dev, "error %d sending QMP %sable request\n",
331 ret, enable ? "en" : "dis");
334 int ipa_power_setup(struct ipa *ipa)
338 ipa_interrupt_add(ipa->interrupt, IPA_IRQ_TX_SUSPEND,
339 ipa_suspend_handler);
341 ret = device_init_wakeup(&ipa->pdev->dev, true);
343 ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_TX_SUSPEND);
348 void ipa_power_teardown(struct ipa *ipa)
350 (void)device_init_wakeup(&ipa->pdev->dev, false);
351 ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_TX_SUSPEND);
354 /* Initialize IPA power management */
356 ipa_power_init(struct device *dev, const struct ipa_power_data *data)
358 struct ipa_power *power;
363 clk = clk_get(dev, "core");
365 dev_err_probe(dev, PTR_ERR(clk), "error getting core clock\n");
367 return ERR_CAST(clk);
370 ret = clk_set_rate(clk, data->core_clock_rate);
372 dev_err(dev, "error %d setting core clock rate to %u\n",
373 ret, data->core_clock_rate);
377 size = struct_size(power, interconnect, data->interconnect_count);
378 power = kzalloc(size, GFP_KERNEL);
385 spin_lock_init(&power->spinlock);
386 power->interconnect_count = data->interconnect_count;
388 ret = ipa_interconnect_init(power, data->interconnect_data);
392 ret = ipa_power_retention_init(power);
394 goto err_interconnect_exit;
396 pm_runtime_set_autosuspend_delay(dev, IPA_AUTOSUSPEND_DELAY);
397 pm_runtime_use_autosuspend(dev);
398 pm_runtime_enable(dev);
402 err_interconnect_exit:
403 ipa_interconnect_exit(power);
412 /* Inverse of ipa_power_init() */
413 void ipa_power_exit(struct ipa_power *power)
415 struct device *dev = power->dev;
416 struct clk *clk = power->core;
418 pm_runtime_disable(dev);
419 pm_runtime_dont_use_autosuspend(dev);
420 ipa_power_retention_exit(power);
421 ipa_interconnect_exit(power);
426 const struct dev_pm_ops ipa_pm_ops = {
427 .suspend = ipa_suspend,
428 .resume = ipa_resume,
429 .runtime_suspend = ipa_runtime_suspend,
430 .runtime_resume = ipa_runtime_resume,