1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
4 */
5
6 #include <linux/bitfield.h>
7 #include <linux/interrupt.h>
8 #include <linux/irq.h>
9 #include <linux/irqdomain.h>
10 #include <linux/mailbox_controller.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13
14 #include <dt-bindings/mailbox/qcom-ipcc.h>
15
16 /* IPCC Register offsets */
17 #define IPCC_REG_SEND_ID 0x0c
18 #define IPCC_REG_RECV_ID 0x10
19 #define IPCC_REG_RECV_SIGNAL_ENABLE 0x14
20 #define IPCC_REG_RECV_SIGNAL_DISABLE 0x18
21 #define IPCC_REG_RECV_SIGNAL_CLEAR 0x1c
22 #define IPCC_REG_CLIENT_CLEAR 0x38
23
24 #define IPCC_SIGNAL_ID_MASK GENMASK(15, 0)
25 #define IPCC_CLIENT_ID_MASK GENMASK(31, 16)
26
27 #define IPCC_NO_PENDING_IRQ GENMASK(31, 0)
28
29 /**
30 * struct qcom_ipcc_chan_info - Per-mailbox-channel info
31 * @client_id: The client-id to which the interrupt has to be triggered
32 * @signal_id: The signal-id to which the interrupt has to be triggered
33 */
34 struct qcom_ipcc_chan_info {
35 u16 client_id;
36 u16 signal_id;
37 };
38
39 /**
40 * struct qcom_ipcc - Holder for the mailbox driver
41 * @dev: Device associated with this instance
42 * @base: Base address of the IPCC frame associated to APSS
43 * @irq_domain: The irq_domain associated with this instance
44 * @chans: The mailbox channels array
45 * @mchan: The per-mailbox channel info array
46 * @mbox: The mailbox controller
47 * @num_chans: Number of @chans elements
48 * @irq: Summary irq
49 */
50 struct qcom_ipcc {
51 struct device *dev;
52 void __iomem *base;
53 struct irq_domain *irq_domain;
54 struct mbox_chan *chans;
55 struct qcom_ipcc_chan_info *mchan;
56 struct mbox_controller mbox;
57 int num_chans;
58 int irq;
59 };
60
to_qcom_ipcc(struct mbox_controller * mbox)61 static inline struct qcom_ipcc *to_qcom_ipcc(struct mbox_controller *mbox)
62 {
63 return container_of(mbox, struct qcom_ipcc, mbox);
64 }
65
qcom_ipcc_get_hwirq(u16 client_id,u16 signal_id)66 static inline u32 qcom_ipcc_get_hwirq(u16 client_id, u16 signal_id)
67 {
68 return FIELD_PREP(IPCC_CLIENT_ID_MASK, client_id) |
69 FIELD_PREP(IPCC_SIGNAL_ID_MASK, signal_id);
70 }
71
qcom_ipcc_irq_fn(int irq,void * data)72 static irqreturn_t qcom_ipcc_irq_fn(int irq, void *data)
73 {
74 struct qcom_ipcc *ipcc = data;
75 u32 hwirq;
76 int virq;
77
78 for (;;) {
79 hwirq = readl(ipcc->base + IPCC_REG_RECV_ID);
80 if (hwirq == IPCC_NO_PENDING_IRQ)
81 break;
82
83 virq = irq_find_mapping(ipcc->irq_domain, hwirq);
84 writel(hwirq, ipcc->base + IPCC_REG_RECV_SIGNAL_CLEAR);
85 generic_handle_irq(virq);
86 }
87
88 return IRQ_HANDLED;
89 }
90
qcom_ipcc_mask_irq(struct irq_data * irqd)91 static void qcom_ipcc_mask_irq(struct irq_data *irqd)
92 {
93 struct qcom_ipcc *ipcc = irq_data_get_irq_chip_data(irqd);
94 irq_hw_number_t hwirq = irqd_to_hwirq(irqd);
95
96 writel(hwirq, ipcc->base + IPCC_REG_RECV_SIGNAL_DISABLE);
97 }
98
qcom_ipcc_unmask_irq(struct irq_data * irqd)99 static void qcom_ipcc_unmask_irq(struct irq_data *irqd)
100 {
101 struct qcom_ipcc *ipcc = irq_data_get_irq_chip_data(irqd);
102 irq_hw_number_t hwirq = irqd_to_hwirq(irqd);
103
104 writel(hwirq, ipcc->base + IPCC_REG_RECV_SIGNAL_ENABLE);
105 }
106
107 static struct irq_chip qcom_ipcc_irq_chip = {
108 .name = "ipcc",
109 .irq_mask = qcom_ipcc_mask_irq,
110 .irq_unmask = qcom_ipcc_unmask_irq,
111 .flags = IRQCHIP_SKIP_SET_WAKE,
112 };
113
qcom_ipcc_domain_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hw)114 static int qcom_ipcc_domain_map(struct irq_domain *d, unsigned int irq,
115 irq_hw_number_t hw)
116 {
117 struct qcom_ipcc *ipcc = d->host_data;
118
119 irq_set_chip_and_handler(irq, &qcom_ipcc_irq_chip, handle_level_irq);
120 irq_set_chip_data(irq, ipcc);
121 irq_set_noprobe(irq);
122
123 return 0;
124 }
125
qcom_ipcc_domain_xlate(struct irq_domain * d,struct device_node * node,const u32 * intspec,unsigned int intsize,unsigned long * out_hwirq,unsigned int * out_type)126 static int qcom_ipcc_domain_xlate(struct irq_domain *d,
127 struct device_node *node, const u32 *intspec,
128 unsigned int intsize,
129 unsigned long *out_hwirq,
130 unsigned int *out_type)
131 {
132 if (intsize != 3)
133 return -EINVAL;
134
135 *out_hwirq = qcom_ipcc_get_hwirq(intspec[0], intspec[1]);
136 *out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
137
138 return 0;
139 }
140
141 static const struct irq_domain_ops qcom_ipcc_irq_ops = {
142 .map = qcom_ipcc_domain_map,
143 .xlate = qcom_ipcc_domain_xlate,
144 };
145
qcom_ipcc_mbox_send_data(struct mbox_chan * chan,void * data)146 static int qcom_ipcc_mbox_send_data(struct mbox_chan *chan, void *data)
147 {
148 struct qcom_ipcc *ipcc = to_qcom_ipcc(chan->mbox);
149 struct qcom_ipcc_chan_info *mchan = chan->con_priv;
150 u32 hwirq;
151
152 hwirq = qcom_ipcc_get_hwirq(mchan->client_id, mchan->signal_id);
153 writel(hwirq, ipcc->base + IPCC_REG_SEND_ID);
154
155 return 0;
156 }
157
qcom_ipcc_mbox_shutdown(struct mbox_chan * chan)158 static void qcom_ipcc_mbox_shutdown(struct mbox_chan *chan)
159 {
160 chan->con_priv = NULL;
161 }
162
qcom_ipcc_mbox_xlate(struct mbox_controller * mbox,const struct of_phandle_args * ph)163 static struct mbox_chan *qcom_ipcc_mbox_xlate(struct mbox_controller *mbox,
164 const struct of_phandle_args *ph)
165 {
166 struct qcom_ipcc *ipcc = to_qcom_ipcc(mbox);
167 struct qcom_ipcc_chan_info *mchan;
168 struct mbox_chan *chan;
169 struct device *dev;
170 int chan_id;
171
172 dev = ipcc->dev;
173
174 if (ph->args_count != 2)
175 return ERR_PTR(-EINVAL);
176
177 for (chan_id = 0; chan_id < mbox->num_chans; chan_id++) {
178 chan = &ipcc->chans[chan_id];
179 mchan = chan->con_priv;
180
181 if (!mchan)
182 break;
183 else if (mchan->client_id == ph->args[0] &&
184 mchan->signal_id == ph->args[1])
185 return ERR_PTR(-EBUSY);
186 }
187
188 if (chan_id >= mbox->num_chans)
189 return ERR_PTR(-EBUSY);
190
191 mchan = devm_kzalloc(dev, sizeof(*mchan), GFP_KERNEL);
192 if (!mchan)
193 return ERR_PTR(-ENOMEM);
194
195 mchan->client_id = ph->args[0];
196 mchan->signal_id = ph->args[1];
197 chan->con_priv = mchan;
198
199 return chan;
200 }
201
202 static const struct mbox_chan_ops ipcc_mbox_chan_ops = {
203 .send_data = qcom_ipcc_mbox_send_data,
204 .shutdown = qcom_ipcc_mbox_shutdown,
205 };
206
qcom_ipcc_setup_mbox(struct qcom_ipcc * ipcc,struct device_node * controller_dn)207 static int qcom_ipcc_setup_mbox(struct qcom_ipcc *ipcc,
208 struct device_node *controller_dn)
209 {
210 struct of_phandle_args curr_ph;
211 struct device_node *client_dn;
212 struct mbox_controller *mbox;
213 struct device *dev = ipcc->dev;
214 int i, j, ret;
215
216 /*
217 * Find out the number of clients interested in this mailbox
218 * and create channels accordingly.
219 */
220 ipcc->num_chans = 0;
221 for_each_node_with_property(client_dn, "mboxes") {
222 if (!of_device_is_available(client_dn))
223 continue;
224 i = of_count_phandle_with_args(client_dn,
225 "mboxes", "#mbox-cells");
226 for (j = 0; j < i; j++) {
227 ret = of_parse_phandle_with_args(client_dn, "mboxes",
228 "#mbox-cells", j, &curr_ph);
229 of_node_put(curr_ph.np);
230 if (!ret && curr_ph.np == controller_dn)
231 ipcc->num_chans++;
232 }
233 }
234
235 /* If no clients are found, skip registering as a mbox controller */
236 if (!ipcc->num_chans)
237 return 0;
238
239 ipcc->chans = devm_kcalloc(dev, ipcc->num_chans,
240 sizeof(struct mbox_chan), GFP_KERNEL);
241 if (!ipcc->chans)
242 return -ENOMEM;
243
244 mbox = &ipcc->mbox;
245 mbox->dev = dev;
246 mbox->num_chans = ipcc->num_chans;
247 mbox->chans = ipcc->chans;
248 mbox->ops = &ipcc_mbox_chan_ops;
249 mbox->of_xlate = qcom_ipcc_mbox_xlate;
250 mbox->txdone_irq = false;
251 mbox->txdone_poll = false;
252
253 return devm_mbox_controller_register(dev, mbox);
254 }
255
qcom_ipcc_pm_resume(struct device * dev)256 static int qcom_ipcc_pm_resume(struct device *dev)
257 {
258 struct qcom_ipcc *ipcc = dev_get_drvdata(dev);
259 u32 hwirq;
260 int virq;
261
262 hwirq = readl(ipcc->base + IPCC_REG_RECV_ID);
263 if (hwirq == IPCC_NO_PENDING_IRQ)
264 return 0;
265
266 virq = irq_find_mapping(ipcc->irq_domain, hwirq);
267
268 dev_dbg(dev, "virq: %d triggered client-id: %ld; signal-id: %ld\n", virq,
269 FIELD_GET(IPCC_CLIENT_ID_MASK, hwirq), FIELD_GET(IPCC_SIGNAL_ID_MASK, hwirq));
270
271 return 0;
272 }
273
qcom_ipcc_probe(struct platform_device * pdev)274 static int qcom_ipcc_probe(struct platform_device *pdev)
275 {
276 struct qcom_ipcc *ipcc;
277 static int id;
278 char *name;
279 int ret;
280
281 ipcc = devm_kzalloc(&pdev->dev, sizeof(*ipcc), GFP_KERNEL);
282 if (!ipcc)
283 return -ENOMEM;
284
285 ipcc->dev = &pdev->dev;
286
287 ipcc->base = devm_platform_ioremap_resource(pdev, 0);
288 if (IS_ERR(ipcc->base))
289 return PTR_ERR(ipcc->base);
290
291 ipcc->irq = platform_get_irq(pdev, 0);
292 if (ipcc->irq < 0)
293 return ipcc->irq;
294
295 name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "ipcc_%d", id++);
296 if (!name)
297 return -ENOMEM;
298
299 ipcc->irq_domain = irq_domain_add_tree(pdev->dev.of_node,
300 &qcom_ipcc_irq_ops, ipcc);
301 if (!ipcc->irq_domain)
302 return -ENOMEM;
303
304 ret = qcom_ipcc_setup_mbox(ipcc, pdev->dev.of_node);
305 if (ret)
306 goto err_mbox;
307
308 ret = devm_request_irq(&pdev->dev, ipcc->irq, qcom_ipcc_irq_fn,
309 IRQF_TRIGGER_HIGH | IRQF_NO_SUSPEND |
310 IRQF_NO_THREAD, name, ipcc);
311 if (ret < 0) {
312 dev_err(&pdev->dev, "Failed to register the irq: %d\n", ret);
313 goto err_req_irq;
314 }
315
316 platform_set_drvdata(pdev, ipcc);
317
318 return 0;
319
320 err_req_irq:
321 if (ipcc->num_chans)
322 mbox_controller_unregister(&ipcc->mbox);
323 err_mbox:
324 irq_domain_remove(ipcc->irq_domain);
325
326 return ret;
327 }
328
qcom_ipcc_remove(struct platform_device * pdev)329 static void qcom_ipcc_remove(struct platform_device *pdev)
330 {
331 struct qcom_ipcc *ipcc = platform_get_drvdata(pdev);
332
333 disable_irq_wake(ipcc->irq);
334 irq_domain_remove(ipcc->irq_domain);
335 }
336
337 static const struct of_device_id qcom_ipcc_of_match[] = {
338 { .compatible = "qcom,ipcc"},
339 {}
340 };
341 MODULE_DEVICE_TABLE(of, qcom_ipcc_of_match);
342
343 static const struct dev_pm_ops qcom_ipcc_dev_pm_ops = {
344 NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, qcom_ipcc_pm_resume)
345 };
346
347 static struct platform_driver qcom_ipcc_driver = {
348 .probe = qcom_ipcc_probe,
349 .remove = qcom_ipcc_remove,
350 .driver = {
351 .name = "qcom-ipcc",
352 .of_match_table = qcom_ipcc_of_match,
353 .suppress_bind_attrs = true,
354 .pm = pm_sleep_ptr(&qcom_ipcc_dev_pm_ops),
355 },
356 };
357
qcom_ipcc_init(void)358 static int __init qcom_ipcc_init(void)
359 {
360 return platform_driver_register(&qcom_ipcc_driver);
361 }
362 arch_initcall(qcom_ipcc_init);
363
364 MODULE_AUTHOR("Venkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>");
365 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
366 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. IPCC driver");
367 MODULE_LICENSE("GPL v2");
368