1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright 2017 NXP
4 * Copyright (C) 2018 Pengutronix, Lucas Stach <kernel@pengutronix.de>
5 */
6
7#include <linux/clk.h>
8#include <linux/interrupt.h>
9#include <linux/irq.h>
10#include <linux/irqchip/chained_irq.h>
11#include <linux/irqdomain.h>
12#include <linux/kernel.h>
13#include <linux/of_irq.h>
14#include <linux/of_platform.h>
15#include <linux/spinlock.h>
16
17#define CTRL_STRIDE_OFF(_t, _r)	(_t * 4 * _r)
18#define CHANCTRL		0x0
19#define CHANMASK(n, t)		(CTRL_STRIDE_OFF(t, 0) + 0x4 * (n) + 0x4)
20#define CHANSET(n, t)		(CTRL_STRIDE_OFF(t, 1) + 0x4 * (n) + 0x4)
21#define CHANSTATUS(n, t)	(CTRL_STRIDE_OFF(t, 2) + 0x4 * (n) + 0x4)
22#define CHAN_MINTDIS(t)		(CTRL_STRIDE_OFF(t, 3) + 0x4)
23#define CHAN_MASTRSTAT(t)	(CTRL_STRIDE_OFF(t, 3) + 0x8)
24
25#define CHAN_MAX_OUTPUT_INT	0x8
26
27struct irqsteer_data {
28	void __iomem		*regs;
29	struct clk		*ipg_clk;
30	int			irq[CHAN_MAX_OUTPUT_INT];
31	int			irq_count;
32	raw_spinlock_t		lock;
33	int			reg_num;
34	int			channel;
35	struct irq_domain	*domain;
36	u32			*saved_reg;
37};
38
39static int imx_irqsteer_get_reg_index(struct irqsteer_data *data,
40				      unsigned long irqnum)
41{
42	return (data->reg_num - irqnum / 32 - 1);
43}
44
45static void imx_irqsteer_irq_unmask(struct irq_data *d)
46{
47	struct irqsteer_data *data = d->chip_data;
48	int idx = imx_irqsteer_get_reg_index(data, d->hwirq);
49	unsigned long flags;
50	u32 val;
51
52	raw_spin_lock_irqsave(&data->lock, flags);
53	val = readl_relaxed(data->regs + CHANMASK(idx, data->reg_num));
54	val |= BIT(d->hwirq % 32);
55	writel_relaxed(val, data->regs + CHANMASK(idx, data->reg_num));
56	raw_spin_unlock_irqrestore(&data->lock, flags);
57}
58
59static void imx_irqsteer_irq_mask(struct irq_data *d)
60{
61	struct irqsteer_data *data = d->chip_data;
62	int idx = imx_irqsteer_get_reg_index(data, d->hwirq);
63	unsigned long flags;
64	u32 val;
65
66	raw_spin_lock_irqsave(&data->lock, flags);
67	val = readl_relaxed(data->regs + CHANMASK(idx, data->reg_num));
68	val &= ~BIT(d->hwirq % 32);
69	writel_relaxed(val, data->regs + CHANMASK(idx, data->reg_num));
70	raw_spin_unlock_irqrestore(&data->lock, flags);
71}
72
73static struct irq_chip imx_irqsteer_irq_chip = {
74	.name		= "irqsteer",
75	.irq_mask	= imx_irqsteer_irq_mask,
76	.irq_unmask	= imx_irqsteer_irq_unmask,
77};
78
79static int imx_irqsteer_irq_map(struct irq_domain *h, unsigned int irq,
80				irq_hw_number_t hwirq)
81{
82	irq_set_status_flags(irq, IRQ_LEVEL);
83	irq_set_chip_data(irq, h->host_data);
84	irq_set_chip_and_handler(irq, &imx_irqsteer_irq_chip, handle_level_irq);
85
86	return 0;
87}
88
89static const struct irq_domain_ops imx_irqsteer_domain_ops = {
90	.map		= imx_irqsteer_irq_map,
91	.xlate		= irq_domain_xlate_onecell,
92};
93
94static int imx_irqsteer_get_hwirq_base(struct irqsteer_data *data, u32 irq)
95{
96	int i;
97
98	for (i = 0; i < data->irq_count; i++) {
99		if (data->irq[i] == irq)
100			return i * 64;
101	}
102
103	return -EINVAL;
104}
105
106static void imx_irqsteer_irq_handler(struct irq_desc *desc)
107{
108	struct irqsteer_data *data = irq_desc_get_handler_data(desc);
109	int hwirq;
110	int irq, i;
111
112	chained_irq_enter(irq_desc_get_chip(desc), desc);
113
114	irq = irq_desc_get_irq(desc);
115	hwirq = imx_irqsteer_get_hwirq_base(data, irq);
116	if (hwirq < 0) {
117		pr_warn("%s: unable to get hwirq base for irq %d\n",
118			__func__, irq);
119		return;
120	}
121
122	for (i = 0; i < 2; i++, hwirq += 32) {
123		int idx = imx_irqsteer_get_reg_index(data, hwirq);
124		unsigned long irqmap;
125		int pos, virq;
126
127		if (hwirq >= data->reg_num * 32)
128			break;
129
130		irqmap = readl_relaxed(data->regs +
131				       CHANSTATUS(idx, data->reg_num));
132
133		for_each_set_bit(pos, &irqmap, 32) {
134			virq = irq_find_mapping(data->domain, pos + hwirq);
135			if (virq)
136				generic_handle_irq(virq);
137		}
138	}
139
140	chained_irq_exit(irq_desc_get_chip(desc), desc);
141}
142
143static int imx_irqsteer_probe(struct platform_device *pdev)
144{
145	struct device_node *np = pdev->dev.of_node;
146	struct irqsteer_data *data;
147	u32 irqs_num;
148	int i, ret;
149
150	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
151	if (!data)
152		return -ENOMEM;
153
154	data->regs = devm_platform_ioremap_resource(pdev, 0);
155	if (IS_ERR(data->regs)) {
156		dev_err(&pdev->dev, "failed to initialize reg\n");
157		return PTR_ERR(data->regs);
158	}
159
160	data->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
161	if (IS_ERR(data->ipg_clk))
162		return dev_err_probe(&pdev->dev, PTR_ERR(data->ipg_clk),
163				     "failed to get ipg clk\n");
164
165	raw_spin_lock_init(&data->lock);
166
167	ret = of_property_read_u32(np, "fsl,num-irqs", &irqs_num);
168	if (ret)
169		return ret;
170	ret = of_property_read_u32(np, "fsl,channel", &data->channel);
171	if (ret)
172		return ret;
173
174	/*
175	 * There is one output irq for each group of 64 inputs.
176	 * One register bit map can represent 32 input interrupts.
177	 */
178	data->irq_count = DIV_ROUND_UP(irqs_num, 64);
179	data->reg_num = irqs_num / 32;
180
181	if (IS_ENABLED(CONFIG_PM_SLEEP)) {
182		data->saved_reg = devm_kzalloc(&pdev->dev,
183					sizeof(u32) * data->reg_num,
184					GFP_KERNEL);
185		if (!data->saved_reg)
186			return -ENOMEM;
187	}
188
189	ret = clk_prepare_enable(data->ipg_clk);
190	if (ret) {
191		dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
192		return ret;
193	}
194
195	/* steer all IRQs into configured channel */
196	writel_relaxed(BIT(data->channel), data->regs + CHANCTRL);
197
198	data->domain = irq_domain_add_linear(np, data->reg_num * 32,
199					     &imx_irqsteer_domain_ops, data);
200	if (!data->domain) {
201		dev_err(&pdev->dev, "failed to create IRQ domain\n");
202		ret = -ENOMEM;
203		goto out;
204	}
205
206	if (!data->irq_count || data->irq_count > CHAN_MAX_OUTPUT_INT) {
207		ret = -EINVAL;
208		goto out;
209	}
210
211	for (i = 0; i < data->irq_count; i++) {
212		data->irq[i] = irq_of_parse_and_map(np, i);
213		if (!data->irq[i]) {
214			ret = -EINVAL;
215			goto out;
216		}
217
218		irq_set_chained_handler_and_data(data->irq[i],
219						 imx_irqsteer_irq_handler,
220						 data);
221	}
222
223	platform_set_drvdata(pdev, data);
224
225	return 0;
226out:
227	clk_disable_unprepare(data->ipg_clk);
228	return ret;
229}
230
231static int imx_irqsteer_remove(struct platform_device *pdev)
232{
233	struct irqsteer_data *irqsteer_data = platform_get_drvdata(pdev);
234	int i;
235
236	for (i = 0; i < irqsteer_data->irq_count; i++)
237		irq_set_chained_handler_and_data(irqsteer_data->irq[i],
238						 NULL, NULL);
239
240	irq_domain_remove(irqsteer_data->domain);
241
242	clk_disable_unprepare(irqsteer_data->ipg_clk);
243
244	return 0;
245}
246
247#ifdef CONFIG_PM_SLEEP
248static void imx_irqsteer_save_regs(struct irqsteer_data *data)
249{
250	int i;
251
252	for (i = 0; i < data->reg_num; i++)
253		data->saved_reg[i] = readl_relaxed(data->regs +
254						CHANMASK(i, data->reg_num));
255}
256
257static void imx_irqsteer_restore_regs(struct irqsteer_data *data)
258{
259	int i;
260
261	writel_relaxed(BIT(data->channel), data->regs + CHANCTRL);
262	for (i = 0; i < data->reg_num; i++)
263		writel_relaxed(data->saved_reg[i],
264			       data->regs + CHANMASK(i, data->reg_num));
265}
266
267static int imx_irqsteer_suspend(struct device *dev)
268{
269	struct irqsteer_data *irqsteer_data = dev_get_drvdata(dev);
270
271	imx_irqsteer_save_regs(irqsteer_data);
272	clk_disable_unprepare(irqsteer_data->ipg_clk);
273
274	return 0;
275}
276
277static int imx_irqsteer_resume(struct device *dev)
278{
279	struct irqsteer_data *irqsteer_data = dev_get_drvdata(dev);
280	int ret;
281
282	ret = clk_prepare_enable(irqsteer_data->ipg_clk);
283	if (ret) {
284		dev_err(dev, "failed to enable ipg clk: %d\n", ret);
285		return ret;
286	}
287	imx_irqsteer_restore_regs(irqsteer_data);
288
289	return 0;
290}
291#endif
292
293static const struct dev_pm_ops imx_irqsteer_pm_ops = {
294	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_irqsteer_suspend, imx_irqsteer_resume)
295};
296
297static const struct of_device_id imx_irqsteer_dt_ids[] = {
298	{ .compatible = "fsl,imx-irqsteer", },
299	{},
300};
301
302static struct platform_driver imx_irqsteer_driver = {
303	.driver = {
304		.name = "imx-irqsteer",
305		.of_match_table = imx_irqsteer_dt_ids,
306		.pm = &imx_irqsteer_pm_ops,
307	},
308	.probe = imx_irqsteer_probe,
309	.remove = imx_irqsteer_remove,
310};
311builtin_platform_driver(imx_irqsteer_driver);
312