1 // SPDX-License-Identifier: GPL-2.0
3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
4 * Copyright (C) 2019-2022 Linaro Ltd.
7 #include <linux/types.h>
8 #include <linux/device.h>
9 #include <linux/interrupt.h>
10 #include <linux/notifier.h>
11 #include <linux/panic_notifier.h>
12 #include <linux/pm_runtime.h>
13 #include <linux/soc/qcom/smem.h>
14 #include <linux/soc/qcom/smem_state.h>
16 #include "ipa_smp2p.h"
21 * DOC: IPA SMP2P communication with the modem
23 * SMP2P is a primitive communication mechanism available between the AP and
24 * the modem. The IPA driver uses this for two purposes: to enable the modem
25 * to state that the GSI hardware is ready to use; and to communicate the
26 * state of IPA power in the event of a crash.
28 * GSI needs to have early initialization completed before it can be used.
29 * This initialization is done either by Trust Zone or by the modem. In the
30 * latter case, the modem uses an SMP2P interrupt to tell the AP IPA driver
31 * when the GSI is ready to use.
33 * The modem is also able to inquire about the current state of IPA
34 * power by trigging another SMP2P interrupt to the AP. We communicate
35 * whether power is enabled using two SMP2P state bits--one to indicate
36 * the power state (on or off), and a second to indicate the power state
37 * bit is valid. The modem will poll the valid bit until it is set, and
38 * at that time records whether the AP has IPA power enabled.
40 * Finally, if the AP kernel panics, we update the SMP2P state bits even if
41 * we never receive an interrupt from the modem requesting this.
45 * struct ipa_smp2p - IPA SMP2P information
47 * @valid_state: SMEM state indicating enabled state is valid
48 * @enabled_state: SMEM state to indicate power is enabled
49 * @valid_bit: Valid bit in 32-bit SMEM state mask
50 * @enabled_bit: Enabled bit in 32-bit SMEM state mask
51 * @enabled_bit: Enabled bit in 32-bit SMEM state mask
52 * @clock_query_irq: IPA interrupt triggered by modem for power query
53 * @setup_ready_irq: IPA interrupt triggered by modem to signal GSI ready
54 * @power_on: Whether IPA power is on
55 * @notified: Whether modem has been notified of power state
56 * @setup_disabled: Whether setup ready interrupt handler is disabled
57 * @mutex: Mutex protecting ready-interrupt/shutdown interlock
58 * @panic_notifier: Panic notifier structure
62 struct qcom_smem_state *valid_state;
63 struct qcom_smem_state *enabled_state;
72 struct notifier_block panic_notifier;
76 * ipa_smp2p_notify() - use SMP2P to tell modem about IPA power state
77 * @smp2p: SMP2P information
79 * This is called either when the modem has requested it (by triggering
80 * the modem power query IPA interrupt) or whenever the AP is shutting down
81 * (via a panic notifier). It sets the two SMP2P state bits--one saying
82 * whether the IPA power is on, and the other indicating the first bit
85 static void ipa_smp2p_notify(struct ipa_smp2p *smp2p)
94 dev = &smp2p->ipa->pdev->dev;
95 smp2p->power_on = pm_runtime_get_if_active(dev, true) > 0;
97 /* Signal whether the IPA power is enabled */
98 mask = BIT(smp2p->enabled_bit);
99 value = smp2p->power_on ? mask : 0;
100 qcom_smem_state_update_bits(smp2p->enabled_state, mask, value);
102 /* Now indicate that the enabled flag is valid */
103 mask = BIT(smp2p->valid_bit);
105 qcom_smem_state_update_bits(smp2p->valid_state, mask, value);
107 smp2p->notified = true;
110 /* Threaded IRQ handler for modem "ipa-clock-query" SMP2P interrupt */
111 static irqreturn_t ipa_smp2p_modem_clk_query_isr(int irq, void *dev_id)
113 struct ipa_smp2p *smp2p = dev_id;
115 ipa_smp2p_notify(smp2p);
120 static int ipa_smp2p_panic_notifier(struct notifier_block *nb,
121 unsigned long action, void *data)
123 struct ipa_smp2p *smp2p;
125 smp2p = container_of(nb, struct ipa_smp2p, panic_notifier);
127 ipa_smp2p_notify(smp2p);
130 ipa_uc_panic_notifier(smp2p->ipa);
135 static int ipa_smp2p_panic_notifier_register(struct ipa_smp2p *smp2p)
137 /* IPA panic handler needs to run before modem shuts down */
138 smp2p->panic_notifier.notifier_call = ipa_smp2p_panic_notifier;
139 smp2p->panic_notifier.priority = INT_MAX; /* Do it early */
141 return atomic_notifier_chain_register(&panic_notifier_list,
142 &smp2p->panic_notifier);
145 static void ipa_smp2p_panic_notifier_unregister(struct ipa_smp2p *smp2p)
147 atomic_notifier_chain_unregister(&panic_notifier_list,
148 &smp2p->panic_notifier);
151 /* Threaded IRQ handler for modem "ipa-setup-ready" SMP2P interrupt */
152 static irqreturn_t ipa_smp2p_modem_setup_ready_isr(int irq, void *dev_id)
154 struct ipa_smp2p *smp2p = dev_id;
158 /* Ignore any (spurious) interrupts received after the first */
159 if (smp2p->ipa->setup_complete)
162 /* Power needs to be active for setup */
163 dev = &smp2p->ipa->pdev->dev;
164 ret = pm_runtime_get_sync(dev);
166 dev_err(dev, "error %d getting power for setup\n", ret);
170 /* An error here won't cause driver shutdown, so warn if one occurs */
171 ret = ipa_setup(smp2p->ipa);
172 WARN(ret != 0, "error %d from ipa_setup()\n", ret);
175 pm_runtime_mark_last_busy(dev);
176 (void)pm_runtime_put_autosuspend(dev);
181 /* Initialize SMP2P interrupts */
182 static int ipa_smp2p_irq_init(struct ipa_smp2p *smp2p, const char *name,
183 irq_handler_t handler)
185 struct device *dev = &smp2p->ipa->pdev->dev;
189 ret = platform_get_irq_byname(smp2p->ipa->pdev, name);
191 return ret ? : -EINVAL;
194 ret = request_threaded_irq(irq, NULL, handler, 0, name, smp2p);
196 dev_err(dev, "error %d requesting \"%s\" IRQ\n", ret, name);
203 static void ipa_smp2p_irq_exit(struct ipa_smp2p *smp2p, u32 irq)
205 free_irq(irq, smp2p);
208 /* Drop the power reference if it was taken in ipa_smp2p_notify() */
209 static void ipa_smp2p_power_release(struct ipa *ipa)
211 struct device *dev = &ipa->pdev->dev;
213 if (!ipa->smp2p->power_on)
216 pm_runtime_mark_last_busy(dev);
217 (void)pm_runtime_put_autosuspend(dev);
218 ipa->smp2p->power_on = false;
221 /* Initialize the IPA SMP2P subsystem */
222 int ipa_smp2p_init(struct ipa *ipa, bool modem_init)
224 struct qcom_smem_state *enabled_state;
225 struct device *dev = &ipa->pdev->dev;
226 struct qcom_smem_state *valid_state;
227 struct ipa_smp2p *smp2p;
232 valid_state = qcom_smem_state_get(dev, "ipa-clock-enabled-valid",
234 if (IS_ERR(valid_state))
235 return PTR_ERR(valid_state);
236 if (valid_bit >= 32) /* BITS_PER_U32 */
239 enabled_state = qcom_smem_state_get(dev, "ipa-clock-enabled",
241 if (IS_ERR(enabled_state))
242 return PTR_ERR(enabled_state);
243 if (enabled_bit >= 32) /* BITS_PER_U32 */
246 smp2p = kzalloc(sizeof(*smp2p), GFP_KERNEL);
252 /* These fields are needed by the power query interrupt
253 * handler, so initialize them now.
255 mutex_init(&smp2p->mutex);
256 smp2p->valid_state = valid_state;
257 smp2p->valid_bit = valid_bit;
258 smp2p->enabled_state = enabled_state;
259 smp2p->enabled_bit = enabled_bit;
261 /* We have enough information saved to handle notifications */
264 ret = ipa_smp2p_irq_init(smp2p, "ipa-clock-query",
265 ipa_smp2p_modem_clk_query_isr);
268 smp2p->clock_query_irq = ret;
270 ret = ipa_smp2p_panic_notifier_register(smp2p);
275 /* Result will be non-zero (negative for error) */
276 ret = ipa_smp2p_irq_init(smp2p, "ipa-setup-ready",
277 ipa_smp2p_modem_setup_ready_isr);
279 goto err_notifier_unregister;
280 smp2p->setup_ready_irq = ret;
285 err_notifier_unregister:
286 ipa_smp2p_panic_notifier_unregister(smp2p);
288 ipa_smp2p_irq_exit(smp2p, smp2p->clock_query_irq);
291 mutex_destroy(&smp2p->mutex);
297 void ipa_smp2p_exit(struct ipa *ipa)
299 struct ipa_smp2p *smp2p = ipa->smp2p;
301 if (smp2p->setup_ready_irq)
302 ipa_smp2p_irq_exit(smp2p, smp2p->setup_ready_irq);
303 ipa_smp2p_panic_notifier_unregister(smp2p);
304 ipa_smp2p_irq_exit(smp2p, smp2p->clock_query_irq);
305 /* We won't get notified any more; drop power reference (if any) */
306 ipa_smp2p_power_release(ipa);
308 mutex_destroy(&smp2p->mutex);
312 void ipa_smp2p_irq_disable_setup(struct ipa *ipa)
314 struct ipa_smp2p *smp2p = ipa->smp2p;
316 if (!smp2p->setup_ready_irq)
319 mutex_lock(&smp2p->mutex);
321 if (!smp2p->setup_disabled) {
322 disable_irq(smp2p->setup_ready_irq);
323 smp2p->setup_disabled = true;
326 mutex_unlock(&smp2p->mutex);
329 /* Reset state tracking whether we have notified the modem */
330 void ipa_smp2p_notify_reset(struct ipa *ipa)
332 struct ipa_smp2p *smp2p = ipa->smp2p;
335 if (!smp2p->notified)
338 ipa_smp2p_power_release(ipa);
340 /* Reset the power enabled valid flag */
341 mask = BIT(smp2p->valid_bit);
342 qcom_smem_state_update_bits(smp2p->valid_state, mask, 0);
344 /* Mark the power disabled for good measure... */
345 mask = BIT(smp2p->enabled_bit);
346 qcom_smem_state_update_bits(smp2p->enabled_state, mask, 0);
348 smp2p->notified = false;