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 int 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 	return 0;
337 }
338 
339 static const struct of_device_id qcom_ipcc_of_match[] = {
340 	{ .compatible = "qcom,ipcc"},
341 	{}
342 };
343 MODULE_DEVICE_TABLE(of, qcom_ipcc_of_match);
344 
345 static const struct dev_pm_ops qcom_ipcc_dev_pm_ops = {
346 	NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, qcom_ipcc_pm_resume)
347 };
348 
349 static struct platform_driver qcom_ipcc_driver = {
350 	.probe = qcom_ipcc_probe,
351 	.remove = qcom_ipcc_remove,
352 	.driver = {
353 		.name = "qcom-ipcc",
354 		.of_match_table = qcom_ipcc_of_match,
355 		.suppress_bind_attrs = true,
356 		.pm = pm_sleep_ptr(&qcom_ipcc_dev_pm_ops),
357 	},
358 };
359 
qcom_ipcc_init(void)360 static int __init qcom_ipcc_init(void)
361 {
362 	return platform_driver_register(&qcom_ipcc_driver);
363 }
364 arch_initcall(qcom_ipcc_init);
365 
366 MODULE_AUTHOR("Venkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>");
367 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
368 MODULE_DESCRIPTION("Qualcomm Technologies, Inc. IPCC driver");
369 MODULE_LICENSE("GPL v2");
370