1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright 2017 NXP
3 
4 /*                     INTMUX Block Diagram
5  *
6  *                               ________________
7  * interrupt source #  0  +---->|                |
8  *                        |     |                |
9  * interrupt source #  1  +++-->|                |
10  *            ...         | |   |   channel # 0  |--------->interrupt out # 0
11  *            ...         | |   |                |
12  *            ...         | |   |                |
13  * interrupt source # X-1 +++-->|________________|
14  *                        | | |
15  *                        | | |
16  *                        | | |  ________________
17  *                        +---->|                |
18  *                        | | | |                |
19  *                        | +-->|                |
20  *                        | | | |   channel # 1  |--------->interrupt out # 1
21  *                        | | +>|                |
22  *                        | | | |                |
23  *                        | | | |________________|
24  *                        | | |
25  *                        | | |
26  *                        | | |       ...
27  *                        | | |       ...
28  *                        | | |
29  *                        | | |  ________________
30  *                        +---->|                |
31  *                          | | |                |
32  *                          +-->|                |
33  *                            | |   channel # N  |--------->interrupt out # N
34  *                            +>|                |
35  *                              |                |
36  *                              |________________|
37  *
38  *
39  * N: Interrupt Channel Instance Number (N=7)
40  * X: Interrupt Source Number for each channel (X=32)
41  *
42  * The INTMUX interrupt multiplexer has 8 channels, each channel receives 32
43  * interrupt sources and generates 1 interrupt output.
44  *
45  */
46 
47 #include <linux/clk.h>
48 #include <linux/interrupt.h>
49 #include <linux/irq.h>
50 #include <linux/irqchip/chained_irq.h>
51 #include <linux/irqdomain.h>
52 #include <linux/kernel.h>
53 #include <linux/of_irq.h>
54 #include <linux/of_platform.h>
55 #include <linux/spinlock.h>
56 #include <linux/pm_runtime.h>
57 
58 #define CHANIER(n)	(0x10 + (0x40 * n))
59 #define CHANIPR(n)	(0x20 + (0x40 * n))
60 
61 #define CHAN_MAX_NUM		0x8
62 
63 struct intmux_irqchip_data {
64 	struct irq_chip		chip;
65 	u32			saved_reg;
66 	int			chanidx;
67 	int			irq;
68 	struct irq_domain	*domain;
69 };
70 
71 struct intmux_data {
72 	raw_spinlock_t			lock;
73 	void __iomem			*regs;
74 	struct clk			*ipg_clk;
75 	int				channum;
76 	struct intmux_irqchip_data	irqchip_data[];
77 };
78 
79 static void imx_intmux_irq_mask(struct irq_data *d)
80 {
81 	struct intmux_irqchip_data *irqchip_data = d->chip_data;
82 	int idx = irqchip_data->chanidx;
83 	struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
84 						irqchip_data[idx]);
85 	unsigned long flags;
86 	void __iomem *reg;
87 	u32 val;
88 
89 	raw_spin_lock_irqsave(&data->lock, flags);
90 	reg = data->regs + CHANIER(idx);
91 	val = readl_relaxed(reg);
92 	/* disable the interrupt source of this channel */
93 	val &= ~BIT(d->hwirq);
94 	writel_relaxed(val, reg);
95 	raw_spin_unlock_irqrestore(&data->lock, flags);
96 }
97 
98 static void imx_intmux_irq_unmask(struct irq_data *d)
99 {
100 	struct intmux_irqchip_data *irqchip_data = d->chip_data;
101 	int idx = irqchip_data->chanidx;
102 	struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
103 						irqchip_data[idx]);
104 	unsigned long flags;
105 	void __iomem *reg;
106 	u32 val;
107 
108 	raw_spin_lock_irqsave(&data->lock, flags);
109 	reg = data->regs + CHANIER(idx);
110 	val = readl_relaxed(reg);
111 	/* enable the interrupt source of this channel */
112 	val |= BIT(d->hwirq);
113 	writel_relaxed(val, reg);
114 	raw_spin_unlock_irqrestore(&data->lock, flags);
115 }
116 
117 static struct irq_chip imx_intmux_irq_chip = {
118 	.name		= "intmux",
119 	.irq_mask	= imx_intmux_irq_mask,
120 	.irq_unmask	= imx_intmux_irq_unmask,
121 };
122 
123 static int imx_intmux_irq_map(struct irq_domain *h, unsigned int irq,
124 			      irq_hw_number_t hwirq)
125 {
126 	struct intmux_irqchip_data *data = h->host_data;
127 
128 	irq_set_chip_data(irq, data);
129 	irq_set_chip_and_handler(irq, &data->chip, handle_level_irq);
130 
131 	return 0;
132 }
133 
134 static int imx_intmux_irq_xlate(struct irq_domain *d, struct device_node *node,
135 				const u32 *intspec, unsigned int intsize,
136 				unsigned long *out_hwirq, unsigned int *out_type)
137 {
138 	struct intmux_irqchip_data *irqchip_data = d->host_data;
139 	int idx = irqchip_data->chanidx;
140 	struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
141 						irqchip_data[idx]);
142 
143 	/*
144 	 * two cells needed in interrupt specifier:
145 	 * the 1st cell: hw interrupt number
146 	 * the 2nd cell: channel index
147 	 */
148 	if (WARN_ON(intsize != 2))
149 		return -EINVAL;
150 
151 	if (WARN_ON(intspec[1] >= data->channum))
152 		return -EINVAL;
153 
154 	*out_hwirq = intspec[0];
155 	*out_type = IRQ_TYPE_LEVEL_HIGH;
156 
157 	return 0;
158 }
159 
160 static int imx_intmux_irq_select(struct irq_domain *d, struct irq_fwspec *fwspec,
161 				 enum irq_domain_bus_token bus_token)
162 {
163 	struct intmux_irqchip_data *irqchip_data = d->host_data;
164 
165 	/* Not for us */
166 	if (fwspec->fwnode != d->fwnode)
167 		return false;
168 
169 	return irqchip_data->chanidx == fwspec->param[1];
170 }
171 
172 static const struct irq_domain_ops imx_intmux_domain_ops = {
173 	.map		= imx_intmux_irq_map,
174 	.xlate		= imx_intmux_irq_xlate,
175 	.select		= imx_intmux_irq_select,
176 };
177 
178 static void imx_intmux_irq_handler(struct irq_desc *desc)
179 {
180 	struct intmux_irqchip_data *irqchip_data = irq_desc_get_handler_data(desc);
181 	int idx = irqchip_data->chanidx;
182 	struct intmux_data *data = container_of(irqchip_data, struct intmux_data,
183 						irqchip_data[idx]);
184 	unsigned long irqstat;
185 	int pos;
186 
187 	chained_irq_enter(irq_desc_get_chip(desc), desc);
188 
189 	/* read the interrupt source pending status of this channel */
190 	irqstat = readl_relaxed(data->regs + CHANIPR(idx));
191 
192 	for_each_set_bit(pos, &irqstat, 32)
193 		generic_handle_domain_irq(irqchip_data->domain, pos);
194 
195 	chained_irq_exit(irq_desc_get_chip(desc), desc);
196 }
197 
198 static int imx_intmux_probe(struct platform_device *pdev)
199 {
200 	struct device_node *np = pdev->dev.of_node;
201 	struct irq_domain *domain;
202 	struct intmux_data *data;
203 	int channum;
204 	int i, ret;
205 
206 	channum = platform_irq_count(pdev);
207 	if (channum == -EPROBE_DEFER) {
208 		return -EPROBE_DEFER;
209 	} else if (channum > CHAN_MAX_NUM) {
210 		dev_err(&pdev->dev, "supports up to %d multiplex channels\n",
211 			CHAN_MAX_NUM);
212 		return -EINVAL;
213 	}
214 
215 	data = devm_kzalloc(&pdev->dev, struct_size(data, irqchip_data, channum), GFP_KERNEL);
216 	if (!data)
217 		return -ENOMEM;
218 
219 	data->regs = devm_platform_ioremap_resource(pdev, 0);
220 	if (IS_ERR(data->regs)) {
221 		dev_err(&pdev->dev, "failed to initialize reg\n");
222 		return PTR_ERR(data->regs);
223 	}
224 
225 	data->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
226 	if (IS_ERR(data->ipg_clk))
227 		return dev_err_probe(&pdev->dev, PTR_ERR(data->ipg_clk),
228 				     "failed to get ipg clk\n");
229 
230 	data->channum = channum;
231 	raw_spin_lock_init(&data->lock);
232 
233 	pm_runtime_get_noresume(&pdev->dev);
234 	pm_runtime_set_active(&pdev->dev);
235 	pm_runtime_enable(&pdev->dev);
236 
237 	ret = clk_prepare_enable(data->ipg_clk);
238 	if (ret) {
239 		dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
240 		return ret;
241 	}
242 
243 	for (i = 0; i < channum; i++) {
244 		data->irqchip_data[i].chip = imx_intmux_irq_chip;
245 		data->irqchip_data[i].chip.parent_device = &pdev->dev;
246 		data->irqchip_data[i].chanidx = i;
247 
248 		data->irqchip_data[i].irq = irq_of_parse_and_map(np, i);
249 		if (data->irqchip_data[i].irq <= 0) {
250 			ret = -EINVAL;
251 			dev_err(&pdev->dev, "failed to get irq\n");
252 			goto out;
253 		}
254 
255 		domain = irq_domain_add_linear(np, 32, &imx_intmux_domain_ops,
256 					       &data->irqchip_data[i]);
257 		if (!domain) {
258 			ret = -ENOMEM;
259 			dev_err(&pdev->dev, "failed to create IRQ domain\n");
260 			goto out;
261 		}
262 		data->irqchip_data[i].domain = domain;
263 
264 		/* disable all interrupt sources of this channel firstly */
265 		writel_relaxed(0, data->regs + CHANIER(i));
266 
267 		irq_set_chained_handler_and_data(data->irqchip_data[i].irq,
268 						 imx_intmux_irq_handler,
269 						 &data->irqchip_data[i]);
270 	}
271 
272 	platform_set_drvdata(pdev, data);
273 
274 	/*
275 	 * Let pm_runtime_put() disable clock.
276 	 * If CONFIG_PM is not enabled, the clock will stay powered.
277 	 */
278 	pm_runtime_put(&pdev->dev);
279 
280 	return 0;
281 out:
282 	clk_disable_unprepare(data->ipg_clk);
283 	return ret;
284 }
285 
286 static int imx_intmux_remove(struct platform_device *pdev)
287 {
288 	struct intmux_data *data = platform_get_drvdata(pdev);
289 	int i;
290 
291 	for (i = 0; i < data->channum; i++) {
292 		/* disable all interrupt sources of this channel */
293 		writel_relaxed(0, data->regs + CHANIER(i));
294 
295 		irq_set_chained_handler_and_data(data->irqchip_data[i].irq,
296 						 NULL, NULL);
297 
298 		irq_domain_remove(data->irqchip_data[i].domain);
299 	}
300 
301 	pm_runtime_disable(&pdev->dev);
302 
303 	return 0;
304 }
305 
306 #ifdef CONFIG_PM
307 static int imx_intmux_runtime_suspend(struct device *dev)
308 {
309 	struct intmux_data *data = dev_get_drvdata(dev);
310 	struct intmux_irqchip_data *irqchip_data;
311 	int i;
312 
313 	for (i = 0; i < data->channum; i++) {
314 		irqchip_data = &data->irqchip_data[i];
315 		irqchip_data->saved_reg = readl_relaxed(data->regs + CHANIER(i));
316 	}
317 
318 	clk_disable_unprepare(data->ipg_clk);
319 
320 	return 0;
321 }
322 
323 static int imx_intmux_runtime_resume(struct device *dev)
324 {
325 	struct intmux_data *data = dev_get_drvdata(dev);
326 	struct intmux_irqchip_data *irqchip_data;
327 	int ret, i;
328 
329 	ret = clk_prepare_enable(data->ipg_clk);
330 	if (ret) {
331 		dev_err(dev, "failed to enable ipg clk: %d\n", ret);
332 		return ret;
333 	}
334 
335 	for (i = 0; i < data->channum; i++) {
336 		irqchip_data = &data->irqchip_data[i];
337 		writel_relaxed(irqchip_data->saved_reg, data->regs + CHANIER(i));
338 	}
339 
340 	return 0;
341 }
342 #endif
343 
344 static const struct dev_pm_ops imx_intmux_pm_ops = {
345 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
346 				      pm_runtime_force_resume)
347 	SET_RUNTIME_PM_OPS(imx_intmux_runtime_suspend,
348 			   imx_intmux_runtime_resume, NULL)
349 };
350 
351 static const struct of_device_id imx_intmux_id[] = {
352 	{ .compatible = "fsl,imx-intmux", },
353 	{ /* sentinel */ },
354 };
355 
356 static struct platform_driver imx_intmux_driver = {
357 	.driver = {
358 		.name = "imx-intmux",
359 		.of_match_table = imx_intmux_id,
360 		.pm = &imx_intmux_pm_ops,
361 	},
362 	.probe = imx_intmux_probe,
363 	.remove = imx_intmux_remove,
364 };
365 builtin_platform_driver(imx_intmux_driver);
366