1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
|
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
* Copyright (C) 2018-2020 Linaro Ltd.
*/
/* DOC: IPA Interrupts
*
* The IPA has an interrupt line distinct from the interrupt used by the GSI
* code. Whereas GSI interrupts are generally related to channel events (like
* transfer completions), IPA interrupts are related to other events related
* to the IPA. Some of the IPA interrupts come from a microcontroller
* embedded in the IPA. Each IPA interrupt type can be both masked and
* acknowledged independent of the others.
*
* Two of the IPA interrupts are initiated by the microcontroller. A third
* can be generated to signal the need for a wakeup/resume when an IPA
* endpoint has been suspended. There are other IPA events, but at this
* time only these three are supported.
*/
#include <linux/types.h>
#include <linux/interrupt.h>
#include "ipa.h"
#include "ipa_clock.h"
#include "ipa_reg.h"
#include "ipa_endpoint.h"
#include "ipa_interrupt.h"
/**
* struct ipa_interrupt - IPA interrupt information
* @ipa: IPA pointer
* @irq: Linux IRQ number used for IPA interrupts
* @enabled: Mask indicating which interrupts are enabled
* @handler: Array of handlers indexed by IPA interrupt ID
*/
struct ipa_interrupt {
struct ipa *ipa;
u32 irq;
u32 enabled;
ipa_irq_handler_t handler[IPA_IRQ_COUNT];
};
/* Returns true if the interrupt type is associated with the microcontroller */
static bool ipa_interrupt_uc(struct ipa_interrupt *interrupt, u32 irq_id)
{
return irq_id == IPA_IRQ_UC_0 || irq_id == IPA_IRQ_UC_1;
}
/* Process a particular interrupt type that has been received */
static void ipa_interrupt_process(struct ipa_interrupt *interrupt, u32 irq_id)
{
bool uc_irq = ipa_interrupt_uc(interrupt, irq_id);
struct ipa *ipa = interrupt->ipa;
u32 mask = BIT(irq_id);
/* For microcontroller interrupts, clear the interrupt right away,
* "to avoid clearing unhandled interrupts."
*/
if (uc_irq)
iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET);
if (irq_id < IPA_IRQ_COUNT && interrupt->handler[irq_id])
interrupt->handler[irq_id](interrupt->ipa, irq_id);
/* Clearing the SUSPEND_TX interrupt also clears the register
* that tells us which suspended endpoint(s) caused the interrupt,
* so defer clearing until after the handler has been called.
*/
if (!uc_irq)
iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET);
}
/* Process all IPA interrupt types that have been signaled */
static void ipa_interrupt_process_all(struct ipa_interrupt *interrupt)
{
struct ipa *ipa = interrupt->ipa;
u32 enabled = interrupt->enabled;
u32 mask;
/* The status register indicates which conditions are present,
* including conditions whose interrupt is not enabled. Handle
* only the enabled ones.
*/
mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET);
while ((mask &= enabled)) {
do {
u32 irq_id = __ffs(mask);
mask ^= BIT(irq_id);
ipa_interrupt_process(interrupt, irq_id);
} while (mask);
mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET);
}
}
/* Threaded part of the IPA IRQ handler */
static irqreturn_t ipa_isr_thread(int irq, void *dev_id)
{
struct ipa_interrupt *interrupt = dev_id;
ipa_clock_get(interrupt->ipa);
ipa_interrupt_process_all(interrupt);
ipa_clock_put(interrupt->ipa);
return IRQ_HANDLED;
}
/* Hard part (i.e., "real" IRQ handler) of the IRQ handler */
static irqreturn_t ipa_isr(int irq, void *dev_id)
{
struct ipa_interrupt *interrupt = dev_id;
struct ipa *ipa = interrupt->ipa;
u32 mask;
mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET);
if (mask & interrupt->enabled)
return IRQ_WAKE_THREAD;
/* Nothing in the mask was supposed to cause an interrupt */
iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET);
dev_err(&ipa->pdev->dev, "%s: unexpected interrupt, mask 0x%08x\n",
__func__, mask);
return IRQ_HANDLED;
}
/* Common function used to enable/disable TX_SUSPEND for an endpoint */
static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt,
u32 endpoint_id, bool enable)
{
struct ipa *ipa = interrupt->ipa;
u32 mask = BIT(endpoint_id);
u32 val;
/* assert(mask & ipa->available); */
val = ioread32(ipa->reg_virt + IPA_REG_SUSPEND_IRQ_EN_OFFSET);
if (enable)
val |= mask;
else
val &= ~mask;
iowrite32(val, ipa->reg_virt + IPA_REG_SUSPEND_IRQ_EN_OFFSET);
}
/* Enable TX_SUSPEND for an endpoint */
void
ipa_interrupt_suspend_enable(struct ipa_interrupt *interrupt, u32 endpoint_id)
{
ipa_interrupt_suspend_control(interrupt, endpoint_id, true);
}
/* Disable TX_SUSPEND for an endpoint */
void
ipa_interrupt_suspend_disable(struct ipa_interrupt *interrupt, u32 endpoint_id)
{
ipa_interrupt_suspend_control(interrupt, endpoint_id, false);
}
/* Clear the suspend interrupt for all endpoints that signaled it */
void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt)
{
struct ipa *ipa = interrupt->ipa;
u32 val;
val = ioread32(ipa->reg_virt + IPA_REG_IRQ_SUSPEND_INFO_OFFSET);
iowrite32(val, ipa->reg_virt + IPA_REG_SUSPEND_IRQ_CLR_OFFSET);
}
/* Simulate arrival of an IPA TX_SUSPEND interrupt */
void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt)
{
ipa_interrupt_process(interrupt, IPA_IRQ_TX_SUSPEND);
}
/* Add a handler for an IPA interrupt */
void ipa_interrupt_add(struct ipa_interrupt *interrupt,
enum ipa_irq_id ipa_irq, ipa_irq_handler_t handler)
{
struct ipa *ipa = interrupt->ipa;
/* assert(ipa_irq < IPA_IRQ_COUNT); */
interrupt->handler[ipa_irq] = handler;
/* Update the IPA interrupt mask to enable it */
interrupt->enabled |= BIT(ipa_irq);
iowrite32(interrupt->enabled, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET);
}
/* Remove the handler for an IPA interrupt type */
void
ipa_interrupt_remove(struct ipa_interrupt *interrupt, enum ipa_irq_id ipa_irq)
{
struct ipa *ipa = interrupt->ipa;
/* assert(ipa_irq < IPA_IRQ_COUNT); */
/* Update the IPA interrupt mask to disable it */
interrupt->enabled &= ~BIT(ipa_irq);
iowrite32(interrupt->enabled, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET);
interrupt->handler[ipa_irq] = NULL;
}
/* Set up the IPA interrupt framework */
struct ipa_interrupt *ipa_interrupt_setup(struct ipa *ipa)
{
struct device *dev = &ipa->pdev->dev;
struct ipa_interrupt *interrupt;
unsigned int irq;
int ret;
ret = platform_get_irq_byname(ipa->pdev, "ipa");
if (ret <= 0) {
dev_err(dev, "DT error %d getting \"ipa\" IRQ property\n",
ret);
return ERR_PTR(ret ? : -EINVAL);
}
irq = ret;
interrupt = kzalloc(sizeof(*interrupt), GFP_KERNEL);
if (!interrupt)
return ERR_PTR(-ENOMEM);
interrupt->ipa = ipa;
interrupt->irq = irq;
/* Start with all IPA interrupts disabled */
iowrite32(0, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET);
ret = request_threaded_irq(irq, ipa_isr, ipa_isr_thread, IRQF_ONESHOT,
"ipa", interrupt);
if (ret) {
dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret);
goto err_kfree;
}
ret = enable_irq_wake(irq);
if (ret) {
dev_err(dev, "error %d enabling wakeup for \"ipa\" IRQ\n", ret);
goto err_free_irq;
}
return interrupt;
err_free_irq:
free_irq(interrupt->irq, interrupt);
err_kfree:
kfree(interrupt);
return ERR_PTR(ret);
}
/* Tear down the IPA interrupt framework */
void ipa_interrupt_teardown(struct ipa_interrupt *interrupt)
{
struct device *dev = &interrupt->ipa->pdev->dev;
int ret;
ret = disable_irq_wake(interrupt->irq);
if (ret)
dev_err(dev, "error %d disabling \"ipa\" IRQ wakeup\n", ret);
free_irq(interrupt->irq, interrupt);
kfree(interrupt);
}
|
