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
27 struct 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
imx_irqsteer_get_reg_index(struct irqsteer_data * data,unsigned long irqnum)39 static 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
imx_irqsteer_irq_unmask(struct irq_data * d)45 static 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
imx_irqsteer_irq_mask(struct irq_data * d)59 static 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
73 static 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
imx_irqsteer_irq_map(struct irq_domain * h,unsigned int irq,irq_hw_number_t hwirq)79 static 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
89 static const struct irq_domain_ops imx_irqsteer_domain_ops = {
90 .map = imx_irqsteer_irq_map,
91 .xlate = irq_domain_xlate_onecell,
92 };
93
imx_irqsteer_get_hwirq_base(struct irqsteer_data * data,u32 irq)94 static 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
imx_irqsteer_irq_handler(struct irq_desc * desc)106 static 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
imx_irqsteer_probe(struct platform_device * pdev)143 static 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 ret = PTR_ERR(data->ipg_clk);
163 if (ret != -EPROBE_DEFER)
164 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
165 return ret;
166 }
167
168 raw_spin_lock_init(&data->lock);
169
170 ret = of_property_read_u32(np, "fsl,num-irqs", &irqs_num);
171 if (ret)
172 return ret;
173 ret = of_property_read_u32(np, "fsl,channel", &data->channel);
174 if (ret)
175 return ret;
176
177 /*
178 * There is one output irq for each group of 64 inputs.
179 * One register bit map can represent 32 input interrupts.
180 */
181 data->irq_count = DIV_ROUND_UP(irqs_num, 64);
182 data->reg_num = irqs_num / 32;
183
184 if (IS_ENABLED(CONFIG_PM_SLEEP)) {
185 data->saved_reg = devm_kzalloc(&pdev->dev,
186 sizeof(u32) * data->reg_num,
187 GFP_KERNEL);
188 if (!data->saved_reg)
189 return -ENOMEM;
190 }
191
192 ret = clk_prepare_enable(data->ipg_clk);
193 if (ret) {
194 dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
195 return ret;
196 }
197
198 /* steer all IRQs into configured channel */
199 writel_relaxed(BIT(data->channel), data->regs + CHANCTRL);
200
201 data->domain = irq_domain_add_linear(np, data->reg_num * 32,
202 &imx_irqsteer_domain_ops, data);
203 if (!data->domain) {
204 dev_err(&pdev->dev, "failed to create IRQ domain\n");
205 ret = -ENOMEM;
206 goto out;
207 }
208
209 if (!data->irq_count || data->irq_count > CHAN_MAX_OUTPUT_INT) {
210 ret = -EINVAL;
211 goto out;
212 }
213
214 for (i = 0; i < data->irq_count; i++) {
215 data->irq[i] = irq_of_parse_and_map(np, i);
216 if (!data->irq[i]) {
217 ret = -EINVAL;
218 goto out;
219 }
220
221 irq_set_chained_handler_and_data(data->irq[i],
222 imx_irqsteer_irq_handler,
223 data);
224 }
225
226 platform_set_drvdata(pdev, data);
227
228 return 0;
229 out:
230 clk_disable_unprepare(data->ipg_clk);
231 return ret;
232 }
233
imx_irqsteer_remove(struct platform_device * pdev)234 static int imx_irqsteer_remove(struct platform_device *pdev)
235 {
236 struct irqsteer_data *irqsteer_data = platform_get_drvdata(pdev);
237 int i;
238
239 for (i = 0; i < irqsteer_data->irq_count; i++)
240 irq_set_chained_handler_and_data(irqsteer_data->irq[i],
241 NULL, NULL);
242
243 irq_domain_remove(irqsteer_data->domain);
244
245 clk_disable_unprepare(irqsteer_data->ipg_clk);
246
247 return 0;
248 }
249
250 #ifdef CONFIG_PM_SLEEP
imx_irqsteer_save_regs(struct irqsteer_data * data)251 static void imx_irqsteer_save_regs(struct irqsteer_data *data)
252 {
253 int i;
254
255 for (i = 0; i < data->reg_num; i++)
256 data->saved_reg[i] = readl_relaxed(data->regs +
257 CHANMASK(i, data->reg_num));
258 }
259
imx_irqsteer_restore_regs(struct irqsteer_data * data)260 static void imx_irqsteer_restore_regs(struct irqsteer_data *data)
261 {
262 int i;
263
264 writel_relaxed(BIT(data->channel), data->regs + CHANCTRL);
265 for (i = 0; i < data->reg_num; i++)
266 writel_relaxed(data->saved_reg[i],
267 data->regs + CHANMASK(i, data->reg_num));
268 }
269
imx_irqsteer_suspend(struct device * dev)270 static int imx_irqsteer_suspend(struct device *dev)
271 {
272 struct irqsteer_data *irqsteer_data = dev_get_drvdata(dev);
273
274 imx_irqsteer_save_regs(irqsteer_data);
275 clk_disable_unprepare(irqsteer_data->ipg_clk);
276
277 return 0;
278 }
279
imx_irqsteer_resume(struct device * dev)280 static int imx_irqsteer_resume(struct device *dev)
281 {
282 struct irqsteer_data *irqsteer_data = dev_get_drvdata(dev);
283 int ret;
284
285 ret = clk_prepare_enable(irqsteer_data->ipg_clk);
286 if (ret) {
287 dev_err(dev, "failed to enable ipg clk: %d\n", ret);
288 return ret;
289 }
290 imx_irqsteer_restore_regs(irqsteer_data);
291
292 return 0;
293 }
294 #endif
295
296 static const struct dev_pm_ops imx_irqsteer_pm_ops = {
297 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_irqsteer_suspend, imx_irqsteer_resume)
298 };
299
300 static const struct of_device_id imx_irqsteer_dt_ids[] = {
301 { .compatible = "fsl,imx-irqsteer", },
302 {},
303 };
304
305 static struct platform_driver imx_irqsteer_driver = {
306 .driver = {
307 .name = "imx-irqsteer",
308 .of_match_table = imx_irqsteer_dt_ids,
309 .pm = &imx_irqsteer_pm_ops,
310 },
311 .probe = imx_irqsteer_probe,
312 .remove = imx_irqsteer_remove,
313 };
314 builtin_platform_driver(imx_irqsteer_driver);
315