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_platform.h>
14 #include <linux/spinlock.h>
15 
16 #define CTRL_STRIDE_OFF(_t, _r)	(_t * 8 * _r)
17 #define CHANCTRL		0x0
18 #define CHANMASK(n, t)		(CTRL_STRIDE_OFF(t, 0) + 0x4 * (n) + 0x4)
19 #define CHANSET(n, t)		(CTRL_STRIDE_OFF(t, 1) + 0x4 * (n) + 0x4)
20 #define CHANSTATUS(n, t)	(CTRL_STRIDE_OFF(t, 2) + 0x4 * (n) + 0x4)
21 #define CHAN_MINTDIS(t)		(CTRL_STRIDE_OFF(t, 3) + 0x4)
22 #define CHAN_MASTRSTAT(t)	(CTRL_STRIDE_OFF(t, 3) + 0x8)
23 
24 struct irqsteer_data {
25 	void __iomem		*regs;
26 	struct clk		*ipg_clk;
27 	int			irq;
28 	raw_spinlock_t		lock;
29 	int			irq_groups;
30 	int			channel;
31 	struct irq_domain	*domain;
32 	u32			*saved_reg;
33 };
34 
35 static int imx_irqsteer_get_reg_index(struct irqsteer_data *data,
36 				      unsigned long irqnum)
37 {
38 	return (data->irq_groups * 2 - irqnum / 32 - 1);
39 }
40 
41 static void imx_irqsteer_irq_unmask(struct irq_data *d)
42 {
43 	struct irqsteer_data *data = d->chip_data;
44 	int idx = imx_irqsteer_get_reg_index(data, d->hwirq);
45 	unsigned long flags;
46 	u32 val;
47 
48 	raw_spin_lock_irqsave(&data->lock, flags);
49 	val = readl_relaxed(data->regs + CHANMASK(idx, data->irq_groups));
50 	val |= BIT(d->hwirq % 32);
51 	writel_relaxed(val, data->regs + CHANMASK(idx, data->irq_groups));
52 	raw_spin_unlock_irqrestore(&data->lock, flags);
53 }
54 
55 static void imx_irqsteer_irq_mask(struct irq_data *d)
56 {
57 	struct irqsteer_data *data = d->chip_data;
58 	int idx = imx_irqsteer_get_reg_index(data, d->hwirq);
59 	unsigned long flags;
60 	u32 val;
61 
62 	raw_spin_lock_irqsave(&data->lock, flags);
63 	val = readl_relaxed(data->regs + CHANMASK(idx, data->irq_groups));
64 	val &= ~BIT(d->hwirq % 32);
65 	writel_relaxed(val, data->regs + CHANMASK(idx, data->irq_groups));
66 	raw_spin_unlock_irqrestore(&data->lock, flags);
67 }
68 
69 static struct irq_chip imx_irqsteer_irq_chip = {
70 	.name		= "irqsteer",
71 	.irq_mask	= imx_irqsteer_irq_mask,
72 	.irq_unmask	= imx_irqsteer_irq_unmask,
73 };
74 
75 static int imx_irqsteer_irq_map(struct irq_domain *h, unsigned int irq,
76 				irq_hw_number_t hwirq)
77 {
78 	irq_set_status_flags(irq, IRQ_LEVEL);
79 	irq_set_chip_data(irq, h->host_data);
80 	irq_set_chip_and_handler(irq, &imx_irqsteer_irq_chip, handle_level_irq);
81 
82 	return 0;
83 }
84 
85 static const struct irq_domain_ops imx_irqsteer_domain_ops = {
86 	.map		= imx_irqsteer_irq_map,
87 	.xlate		= irq_domain_xlate_onecell,
88 };
89 
90 static void imx_irqsteer_irq_handler(struct irq_desc *desc)
91 {
92 	struct irqsteer_data *data = irq_desc_get_handler_data(desc);
93 	int i;
94 
95 	chained_irq_enter(irq_desc_get_chip(desc), desc);
96 
97 	for (i = 0; i < data->irq_groups * 64; i += 32) {
98 		int idx = imx_irqsteer_get_reg_index(data, i);
99 		unsigned long irqmap;
100 		int pos, virq;
101 
102 		irqmap = readl_relaxed(data->regs +
103 				       CHANSTATUS(idx, data->irq_groups));
104 
105 		for_each_set_bit(pos, &irqmap, 32) {
106 			virq = irq_find_mapping(data->domain, pos + i);
107 			if (virq)
108 				generic_handle_irq(virq);
109 		}
110 	}
111 
112 	chained_irq_exit(irq_desc_get_chip(desc), desc);
113 }
114 
115 static int imx_irqsteer_probe(struct platform_device *pdev)
116 {
117 	struct device_node *np = pdev->dev.of_node;
118 	struct irqsteer_data *data;
119 	struct resource *res;
120 	int ret;
121 
122 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
123 	if (!data)
124 		return -ENOMEM;
125 
126 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
127 	data->regs = devm_ioremap_resource(&pdev->dev, res);
128 	if (IS_ERR(data->regs)) {
129 		dev_err(&pdev->dev, "failed to initialize reg\n");
130 		return PTR_ERR(data->regs);
131 	}
132 
133 	data->irq = platform_get_irq(pdev, 0);
134 	if (data->irq <= 0) {
135 		dev_err(&pdev->dev, "failed to get irq\n");
136 		return -ENODEV;
137 	}
138 
139 	data->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
140 	if (IS_ERR(data->ipg_clk)) {
141 		ret = PTR_ERR(data->ipg_clk);
142 		if (ret != -EPROBE_DEFER)
143 			dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
144 		return ret;
145 	}
146 
147 	raw_spin_lock_init(&data->lock);
148 
149 	of_property_read_u32(np, "fsl,irq-groups", &data->irq_groups);
150 	of_property_read_u32(np, "fsl,channel", &data->channel);
151 
152 	if (IS_ENABLED(CONFIG_PM_SLEEP)) {
153 		data->saved_reg = devm_kzalloc(&pdev->dev,
154 					sizeof(u32) * data->irq_groups * 2,
155 					GFP_KERNEL);
156 		if (!data->saved_reg)
157 			return -ENOMEM;
158 	}
159 
160 	ret = clk_prepare_enable(data->ipg_clk);
161 	if (ret) {
162 		dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
163 		return ret;
164 	}
165 
166 	/* steer all IRQs into configured channel */
167 	writel_relaxed(BIT(data->channel), data->regs + CHANCTRL);
168 
169 	data->domain = irq_domain_add_linear(np, data->irq_groups * 64,
170 					     &imx_irqsteer_domain_ops, data);
171 	if (!data->domain) {
172 		dev_err(&pdev->dev, "failed to create IRQ domain\n");
173 		clk_disable_unprepare(data->ipg_clk);
174 		return -ENOMEM;
175 	}
176 
177 	irq_set_chained_handler_and_data(data->irq, imx_irqsteer_irq_handler,
178 					 data);
179 
180 	platform_set_drvdata(pdev, data);
181 
182 	return 0;
183 }
184 
185 static int imx_irqsteer_remove(struct platform_device *pdev)
186 {
187 	struct irqsteer_data *irqsteer_data = platform_get_drvdata(pdev);
188 
189 	irq_set_chained_handler_and_data(irqsteer_data->irq, NULL, NULL);
190 	irq_domain_remove(irqsteer_data->domain);
191 
192 	clk_disable_unprepare(irqsteer_data->ipg_clk);
193 
194 	return 0;
195 }
196 
197 #ifdef CONFIG_PM_SLEEP
198 static void imx_irqsteer_save_regs(struct irqsteer_data *data)
199 {
200 	int i;
201 
202 	for (i = 0; i < data->irq_groups * 2; i++)
203 		data->saved_reg[i] = readl_relaxed(data->regs +
204 						CHANMASK(i, data->irq_groups));
205 }
206 
207 static void imx_irqsteer_restore_regs(struct irqsteer_data *data)
208 {
209 	int i;
210 
211 	writel_relaxed(BIT(data->channel), data->regs + CHANCTRL);
212 	for (i = 0; i < data->irq_groups * 2; i++)
213 		writel_relaxed(data->saved_reg[i],
214 			       data->regs + CHANMASK(i, data->irq_groups));
215 }
216 
217 static int imx_irqsteer_suspend(struct device *dev)
218 {
219 	struct irqsteer_data *irqsteer_data = dev_get_drvdata(dev);
220 
221 	imx_irqsteer_save_regs(irqsteer_data);
222 	clk_disable_unprepare(irqsteer_data->ipg_clk);
223 
224 	return 0;
225 }
226 
227 static int imx_irqsteer_resume(struct device *dev)
228 {
229 	struct irqsteer_data *irqsteer_data = dev_get_drvdata(dev);
230 	int ret;
231 
232 	ret = clk_prepare_enable(irqsteer_data->ipg_clk);
233 	if (ret) {
234 		dev_err(dev, "failed to enable ipg clk: %d\n", ret);
235 		return ret;
236 	}
237 	imx_irqsteer_restore_regs(irqsteer_data);
238 
239 	return 0;
240 }
241 #endif
242 
243 static const struct dev_pm_ops imx_irqsteer_pm_ops = {
244 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_irqsteer_suspend, imx_irqsteer_resume)
245 };
246 
247 static const struct of_device_id imx_irqsteer_dt_ids[] = {
248 	{ .compatible = "fsl,imx-irqsteer", },
249 	{},
250 };
251 
252 static struct platform_driver imx_irqsteer_driver = {
253 	.driver = {
254 		.name = "imx-irqsteer",
255 		.of_match_table = imx_irqsteer_dt_ids,
256 		.pm = &imx_irqsteer_pm_ops,
257 	},
258 	.probe = imx_irqsteer_probe,
259 	.remove = imx_irqsteer_remove,
260 };
261 builtin_platform_driver(imx_irqsteer_driver);
262