1ba764c4dSAlex Elder // SPDX-License-Identifier: GPL-2.0
2ba764c4dSAlex Elder
3ba764c4dSAlex Elder /* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
4a4388da5SAlex Elder * Copyright (C) 2018-2022 Linaro Ltd.
5ba764c4dSAlex Elder */
6ba764c4dSAlex Elder
7ba764c4dSAlex Elder /* DOC: IPA Interrupts
8ba764c4dSAlex Elder *
9ba764c4dSAlex Elder * The IPA has an interrupt line distinct from the interrupt used by the GSI
10ba764c4dSAlex Elder * code. Whereas GSI interrupts are generally related to channel events (like
11ba764c4dSAlex Elder * transfer completions), IPA interrupts are related to other events related
12ba764c4dSAlex Elder * to the IPA. Some of the IPA interrupts come from a microcontroller
13ba764c4dSAlex Elder * embedded in the IPA. Each IPA interrupt type can be both masked and
14ba764c4dSAlex Elder * acknowledged independent of the others.
15ba764c4dSAlex Elder *
16ba764c4dSAlex Elder * Two of the IPA interrupts are initiated by the microcontroller. A third
17ba764c4dSAlex Elder * can be generated to signal the need for a wakeup/resume when an IPA
18ba764c4dSAlex Elder * endpoint has been suspended. There are other IPA events, but at this
19ba764c4dSAlex Elder * time only these three are supported.
20ba764c4dSAlex Elder */
21ba764c4dSAlex Elder
22ba764c4dSAlex Elder #include <linux/types.h>
23ba764c4dSAlex Elder #include <linux/interrupt.h>
24c3f115aaSAlex Elder #include <linux/pm_runtime.h>
25df54fde4SCaleb Connolly #include <linux/pm_wakeirq.h>
26ba764c4dSAlex Elder
27ba764c4dSAlex Elder #include "ipa.h"
28ba764c4dSAlex Elder #include "ipa_reg.h"
29ba764c4dSAlex Elder #include "ipa_endpoint.h"
30482ae3a9SAlex Elder #include "ipa_power.h"
31482ae3a9SAlex Elder #include "ipa_uc.h"
32ba764c4dSAlex Elder #include "ipa_interrupt.h"
33ba764c4dSAlex Elder
34ba764c4dSAlex Elder /**
35ba764c4dSAlex Elder * struct ipa_interrupt - IPA interrupt information
36ba764c4dSAlex Elder * @ipa: IPA pointer
37ba764c4dSAlex Elder * @irq: Linux IRQ number used for IPA interrupts
38ba764c4dSAlex Elder * @enabled: Mask indicating which interrupts are enabled
39ba764c4dSAlex Elder */
40ba764c4dSAlex Elder struct ipa_interrupt {
41ba764c4dSAlex Elder struct ipa *ipa;
42ba764c4dSAlex Elder u32 irq;
43ba764c4dSAlex Elder u32 enabled;
44ba764c4dSAlex Elder };
45ba764c4dSAlex Elder
46ba764c4dSAlex Elder /* Process a particular interrupt type that has been received */
ipa_interrupt_process(struct ipa_interrupt * interrupt,u32 irq_id)47ba764c4dSAlex Elder static void ipa_interrupt_process(struct ipa_interrupt *interrupt, u32 irq_id)
48ba764c4dSAlex Elder {
49ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa;
5081772e44SAlex Elder const struct reg *reg;
51ba764c4dSAlex Elder u32 mask = BIT(irq_id);
52e666aa97SAlex Elder u32 offset;
53ba764c4dSAlex Elder
546a244b75SAlex Elder reg = ipa_reg(ipa, IPA_IRQ_CLR);
55fc4cecf7SAlex Elder offset = reg_offset(reg);
56ba764c4dSAlex Elder
57bfb79854SAlex Elder switch (irq_id) {
58bfb79854SAlex Elder case IPA_IRQ_UC_0:
59bfb79854SAlex Elder case IPA_IRQ_UC_1:
60bfb79854SAlex Elder /* For microcontroller interrupts, clear the interrupt right
61bfb79854SAlex Elder * away, "to avoid clearing unhandled interrupts."
62ba764c4dSAlex Elder */
63e666aa97SAlex Elder iowrite32(mask, ipa->reg_virt + offset);
64bfb79854SAlex Elder ipa_uc_interrupt_handler(ipa, irq_id);
65bfb79854SAlex Elder break;
66bfb79854SAlex Elder
67bfb79854SAlex Elder case IPA_IRQ_TX_SUSPEND:
68bfb79854SAlex Elder /* Clearing the SUSPEND_TX interrupt also clears the
69bfb79854SAlex Elder * register that tells us which suspended endpoint(s)
70bfb79854SAlex Elder * caused the interrupt, so defer clearing until after
71bfb79854SAlex Elder * the handler has been called.
72bfb79854SAlex Elder */
73bfb79854SAlex Elder ipa_power_suspend_handler(ipa, irq_id);
74bfb79854SAlex Elder fallthrough;
75bfb79854SAlex Elder
76bfb79854SAlex Elder default: /* Silently ignore (and clear) any other condition */
77bfb79854SAlex Elder iowrite32(mask, ipa->reg_virt + offset);
78bfb79854SAlex Elder break;
79bfb79854SAlex Elder }
80ba764c4dSAlex Elder }
81ba764c4dSAlex Elder
82176086d8SAlex Elder /* IPA IRQ handler is threaded */
ipa_isr_thread(int irq,void * dev_id)83176086d8SAlex Elder static irqreturn_t ipa_isr_thread(int irq, void *dev_id)
84ba764c4dSAlex Elder {
85176086d8SAlex Elder struct ipa_interrupt *interrupt = dev_id;
86ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa;
87ba764c4dSAlex Elder u32 enabled = interrupt->enabled;
8881772e44SAlex Elder const struct reg *reg;
89c3f115aaSAlex Elder struct device *dev;
90e70e410fSAlex Elder u32 pending;
91e666aa97SAlex Elder u32 offset;
92ba764c4dSAlex Elder u32 mask;
937ebd168cSAlex Elder int ret;
94ba764c4dSAlex Elder
95c3f115aaSAlex Elder dev = &ipa->pdev->dev;
96c3f115aaSAlex Elder ret = pm_runtime_get_sync(dev);
977ebd168cSAlex Elder if (WARN_ON(ret < 0))
98c3f115aaSAlex Elder goto out_power_put;
99176086d8SAlex Elder
100ba764c4dSAlex Elder /* The status register indicates which conditions are present,
101ba764c4dSAlex Elder * including conditions whose interrupt is not enabled. Handle
102ba764c4dSAlex Elder * only the enabled ones.
103ba764c4dSAlex Elder */
1046a244b75SAlex Elder reg = ipa_reg(ipa, IPA_IRQ_STTS);
105fc4cecf7SAlex Elder offset = reg_offset(reg);
106e70e410fSAlex Elder pending = ioread32(ipa->reg_virt + offset);
107e70e410fSAlex Elder while ((mask = pending & enabled)) {
108ba764c4dSAlex Elder do {
109ba764c4dSAlex Elder u32 irq_id = __ffs(mask);
110ba764c4dSAlex Elder
111ba764c4dSAlex Elder mask ^= BIT(irq_id);
112ba764c4dSAlex Elder
113ba764c4dSAlex Elder ipa_interrupt_process(interrupt, irq_id);
114ba764c4dSAlex Elder } while (mask);
115e70e410fSAlex Elder pending = ioread32(ipa->reg_virt + offset);
116e70e410fSAlex Elder }
117e70e410fSAlex Elder
118e70e410fSAlex Elder /* If any disabled interrupts are pending, clear them */
119e70e410fSAlex Elder if (pending) {
120e70e410fSAlex Elder dev_dbg(dev, "clearing disabled IPA interrupts 0x%08x\n",
121e70e410fSAlex Elder pending);
1226a244b75SAlex Elder reg = ipa_reg(ipa, IPA_IRQ_CLR);
123fc4cecf7SAlex Elder iowrite32(pending, ipa->reg_virt + reg_offset(reg));
124ba764c4dSAlex Elder }
125c3f115aaSAlex Elder out_power_put:
1261aac309dSAlex Elder pm_runtime_mark_last_busy(dev);
1271aac309dSAlex Elder (void)pm_runtime_put_autosuspend(dev);
128937a0da4SAlex Elder
129ba764c4dSAlex Elder return IRQ_HANDLED;
130ba764c4dSAlex Elder }
131ba764c4dSAlex Elder
ipa_interrupt_enabled_update(struct ipa * ipa)1328e461e1fSAlex Elder static void ipa_interrupt_enabled_update(struct ipa *ipa)
1338e461e1fSAlex Elder {
13481772e44SAlex Elder const struct reg *reg = ipa_reg(ipa, IPA_IRQ_EN);
1358e461e1fSAlex Elder
136fc4cecf7SAlex Elder iowrite32(ipa->interrupt->enabled, ipa->reg_virt + reg_offset(reg));
1378e461e1fSAlex Elder }
1388e461e1fSAlex Elder
1398e461e1fSAlex Elder /* Enable an IPA interrupt type */
ipa_interrupt_enable(struct ipa * ipa,enum ipa_irq_id ipa_irq)140d50ed355SAlex Elder void ipa_interrupt_enable(struct ipa *ipa, enum ipa_irq_id ipa_irq)
1418e461e1fSAlex Elder {
1428e461e1fSAlex Elder /* Update the IPA interrupt mask to enable it */
1438e461e1fSAlex Elder ipa->interrupt->enabled |= BIT(ipa_irq);
1448e461e1fSAlex Elder ipa_interrupt_enabled_update(ipa);
1458e461e1fSAlex Elder }
1468e461e1fSAlex Elder
1478e461e1fSAlex Elder /* Disable an IPA interrupt type */
ipa_interrupt_disable(struct ipa * ipa,enum ipa_irq_id ipa_irq)148d50ed355SAlex Elder void ipa_interrupt_disable(struct ipa *ipa, enum ipa_irq_id ipa_irq)
1498e461e1fSAlex Elder {
1508e461e1fSAlex Elder /* Update the IPA interrupt mask to disable it */
1518e461e1fSAlex Elder ipa->interrupt->enabled &= ~BIT(ipa_irq);
1528e461e1fSAlex Elder ipa_interrupt_enabled_update(ipa);
1538e461e1fSAlex Elder }
1548e461e1fSAlex Elder
ipa_interrupt_irq_disable(struct ipa * ipa)1559ec9b2a3SCaleb Connolly void ipa_interrupt_irq_disable(struct ipa *ipa)
1569ec9b2a3SCaleb Connolly {
1579ec9b2a3SCaleb Connolly disable_irq(ipa->interrupt->irq);
1589ec9b2a3SCaleb Connolly }
1599ec9b2a3SCaleb Connolly
ipa_interrupt_irq_enable(struct ipa * ipa)1609ec9b2a3SCaleb Connolly void ipa_interrupt_irq_enable(struct ipa *ipa)
1619ec9b2a3SCaleb Connolly {
1629ec9b2a3SCaleb Connolly enable_irq(ipa->interrupt->irq);
1639ec9b2a3SCaleb Connolly }
1649ec9b2a3SCaleb Connolly
165ba764c4dSAlex Elder /* Common function used to enable/disable TX_SUSPEND for an endpoint */
ipa_interrupt_suspend_control(struct ipa_interrupt * interrupt,u32 endpoint_id,bool enable)166ba764c4dSAlex Elder static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt,
167ba764c4dSAlex Elder u32 endpoint_id, bool enable)
168ba764c4dSAlex Elder {
169ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa;
170d9d71a89SAlex Elder u32 mask = BIT(endpoint_id % 32);
171f298ba78SAlex Elder u32 unit = endpoint_id / 32;
17281772e44SAlex Elder const struct reg *reg;
173e666aa97SAlex Elder u32 offset;
174ba764c4dSAlex Elder u32 val;
175ba764c4dSAlex Elder
17688de7672SAlex Elder WARN_ON(!test_bit(endpoint_id, ipa->available));
177e666aa97SAlex Elder
178e666aa97SAlex Elder /* IPA version 3.0 does not support TX_SUSPEND interrupt control */
179e666aa97SAlex Elder if (ipa->version == IPA_VERSION_3_0)
180e666aa97SAlex Elder return;
181e666aa97SAlex Elder
1826a244b75SAlex Elder reg = ipa_reg(ipa, IRQ_SUSPEND_EN);
183fc4cecf7SAlex Elder offset = reg_n_offset(reg, unit);
184e666aa97SAlex Elder val = ioread32(ipa->reg_virt + offset);
18588de7672SAlex Elder
186ba764c4dSAlex Elder if (enable)
187ba764c4dSAlex Elder val |= mask;
188ba764c4dSAlex Elder else
189ba764c4dSAlex Elder val &= ~mask;
19088de7672SAlex Elder
191e666aa97SAlex Elder iowrite32(val, ipa->reg_virt + offset);
192ba764c4dSAlex Elder }
193ba764c4dSAlex Elder
194ba764c4dSAlex Elder /* Enable TX_SUSPEND for an endpoint */
195ba764c4dSAlex Elder void
ipa_interrupt_suspend_enable(struct ipa_interrupt * interrupt,u32 endpoint_id)196ba764c4dSAlex Elder ipa_interrupt_suspend_enable(struct ipa_interrupt *interrupt, u32 endpoint_id)
197ba764c4dSAlex Elder {
198ba764c4dSAlex Elder ipa_interrupt_suspend_control(interrupt, endpoint_id, true);
199ba764c4dSAlex Elder }
200ba764c4dSAlex Elder
201ba764c4dSAlex Elder /* Disable TX_SUSPEND for an endpoint */
202ba764c4dSAlex Elder void
ipa_interrupt_suspend_disable(struct ipa_interrupt * interrupt,u32 endpoint_id)203ba764c4dSAlex Elder ipa_interrupt_suspend_disable(struct ipa_interrupt *interrupt, u32 endpoint_id)
204ba764c4dSAlex Elder {
205ba764c4dSAlex Elder ipa_interrupt_suspend_control(interrupt, endpoint_id, false);
206ba764c4dSAlex Elder }
207ba764c4dSAlex Elder
208ba764c4dSAlex Elder /* Clear the suspend interrupt for all endpoints that signaled it */
ipa_interrupt_suspend_clear_all(struct ipa_interrupt * interrupt)209ba764c4dSAlex Elder void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt)
210ba764c4dSAlex Elder {
211ba764c4dSAlex Elder struct ipa *ipa = interrupt->ipa;
212f298ba78SAlex Elder u32 unit_count;
213f298ba78SAlex Elder u32 unit;
214f298ba78SAlex Elder
215*0a32395fSAlex Elder unit_count = DIV_ROUND_UP(ipa->endpoint_count, 32);
216f298ba78SAlex Elder for (unit = 0; unit < unit_count; unit++) {
21781772e44SAlex Elder const struct reg *reg;
218ba764c4dSAlex Elder u32 val;
219ba764c4dSAlex Elder
2206a244b75SAlex Elder reg = ipa_reg(ipa, IRQ_SUSPEND_INFO);
221fc4cecf7SAlex Elder val = ioread32(ipa->reg_virt + reg_n_offset(reg, unit));
222e666aa97SAlex Elder
223e666aa97SAlex Elder /* SUSPEND interrupt status isn't cleared on IPA version 3.0 */
224e666aa97SAlex Elder if (ipa->version == IPA_VERSION_3_0)
225f298ba78SAlex Elder continue;
226e666aa97SAlex Elder
2276a244b75SAlex Elder reg = ipa_reg(ipa, IRQ_SUSPEND_CLR);
228fc4cecf7SAlex Elder iowrite32(val, ipa->reg_virt + reg_n_offset(reg, unit));
229f298ba78SAlex Elder }
230ba764c4dSAlex Elder }
231ba764c4dSAlex Elder
232ba764c4dSAlex Elder /* Simulate arrival of an IPA TX_SUSPEND interrupt */
ipa_interrupt_simulate_suspend(struct ipa_interrupt * interrupt)233ba764c4dSAlex Elder void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt)
234ba764c4dSAlex Elder {
235ba764c4dSAlex Elder ipa_interrupt_process(interrupt, IPA_IRQ_TX_SUSPEND);
236ba764c4dSAlex Elder }
237ba764c4dSAlex Elder
2381118a147SAlex Elder /* Configure the IPA interrupt framework */
ipa_interrupt_config(struct ipa * ipa)2391118a147SAlex Elder struct ipa_interrupt *ipa_interrupt_config(struct ipa *ipa)
240ba764c4dSAlex Elder {
241ba764c4dSAlex Elder struct device *dev = &ipa->pdev->dev;
242ba764c4dSAlex Elder struct ipa_interrupt *interrupt;
24381772e44SAlex Elder const struct reg *reg;
244ba764c4dSAlex Elder unsigned int irq;
245ba764c4dSAlex Elder int ret;
246ba764c4dSAlex Elder
247ba764c4dSAlex Elder ret = platform_get_irq_byname(ipa->pdev, "ipa");
248ba764c4dSAlex Elder if (ret <= 0) {
249ba764c4dSAlex Elder dev_err(dev, "DT error %d getting \"ipa\" IRQ property\n",
250ba764c4dSAlex Elder ret);
251ba764c4dSAlex Elder return ERR_PTR(ret ? : -EINVAL);
252ba764c4dSAlex Elder }
253ba764c4dSAlex Elder irq = ret;
254ba764c4dSAlex Elder
255ba764c4dSAlex Elder interrupt = kzalloc(sizeof(*interrupt), GFP_KERNEL);
256ba764c4dSAlex Elder if (!interrupt)
257ba764c4dSAlex Elder return ERR_PTR(-ENOMEM);
258ba764c4dSAlex Elder interrupt->ipa = ipa;
259ba764c4dSAlex Elder interrupt->irq = irq;
260ba764c4dSAlex Elder
261ba764c4dSAlex Elder /* Start with all IPA interrupts disabled */
2626a244b75SAlex Elder reg = ipa_reg(ipa, IPA_IRQ_EN);
263fc4cecf7SAlex Elder iowrite32(0, ipa->reg_virt + reg_offset(reg));
264ba764c4dSAlex Elder
265937a0da4SAlex Elder ret = request_threaded_irq(irq, NULL, ipa_isr_thread, IRQF_ONESHOT,
266ba764c4dSAlex Elder "ipa", interrupt);
267ba764c4dSAlex Elder if (ret) {
268ba764c4dSAlex Elder dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret);
269ba764c4dSAlex Elder goto err_kfree;
270ba764c4dSAlex Elder }
271ba764c4dSAlex Elder
272df54fde4SCaleb Connolly ret = dev_pm_set_wake_irq(dev, irq);
273d1b5126aSAlex Elder if (ret) {
274df54fde4SCaleb Connolly dev_err(dev, "error %d registering \"ipa\" IRQ as wakeirq\n", ret);
275d1b5126aSAlex Elder goto err_free_irq;
276d1b5126aSAlex Elder }
277d1b5126aSAlex Elder
278ba764c4dSAlex Elder return interrupt;
279ba764c4dSAlex Elder
280d1b5126aSAlex Elder err_free_irq:
281d1b5126aSAlex Elder free_irq(interrupt->irq, interrupt);
282ba764c4dSAlex Elder err_kfree:
283ba764c4dSAlex Elder kfree(interrupt);
284ba764c4dSAlex Elder
285ba764c4dSAlex Elder return ERR_PTR(ret);
286ba764c4dSAlex Elder }
287ba764c4dSAlex Elder
2881118a147SAlex Elder /* Inverse of ipa_interrupt_config() */
ipa_interrupt_deconfig(struct ipa_interrupt * interrupt)2891118a147SAlex Elder void ipa_interrupt_deconfig(struct ipa_interrupt *interrupt)
290ba764c4dSAlex Elder {
291d1b5126aSAlex Elder struct device *dev = &interrupt->ipa->pdev->dev;
292d1b5126aSAlex Elder
293df54fde4SCaleb Connolly dev_pm_clear_wake_irq(dev);
294ba764c4dSAlex Elder free_irq(interrupt->irq, interrupt);
295ba764c4dSAlex Elder kfree(interrupt);
296ba764c4dSAlex Elder }
297