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  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
 63struct 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
 71struct 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
 79static 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
 98static 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
117static 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
123static 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
134static 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
160static 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
172static 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
178static 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, virq;
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		virq = irq_find_mapping(irqchip_data->domain, pos);
194		if (virq)
195			generic_handle_irq(virq);
196	}
197
198	chained_irq_exit(irq_desc_get_chip(desc), desc);
199}
200
201static int imx_intmux_probe(struct platform_device *pdev)
202{
203	struct device_node *np = pdev->dev.of_node;
204	struct irq_domain *domain;
205	struct intmux_data *data;
206	int channum;
207	int i, ret;
208
209	channum = platform_irq_count(pdev);
210	if (channum == -EPROBE_DEFER) {
211		return -EPROBE_DEFER;
212	} else if (channum > CHAN_MAX_NUM) {
213		dev_err(&pdev->dev, "supports up to %d multiplex channels\n",
214			CHAN_MAX_NUM);
215		return -EINVAL;
216	}
217
218	data = devm_kzalloc(&pdev->dev, struct_size(data, irqchip_data, channum), GFP_KERNEL);
219	if (!data)
220		return -ENOMEM;
221
222	data->regs = devm_platform_ioremap_resource(pdev, 0);
223	if (IS_ERR(data->regs)) {
224		dev_err(&pdev->dev, "failed to initialize reg\n");
225		return PTR_ERR(data->regs);
226	}
227
228	data->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
229	if (IS_ERR(data->ipg_clk)) {
230		ret = PTR_ERR(data->ipg_clk);
231		if (ret != -EPROBE_DEFER)
232			dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
233		return ret;
234	}
235
236	data->channum = channum;
237	raw_spin_lock_init(&data->lock);
238
239	pm_runtime_get_noresume(&pdev->dev);
240	pm_runtime_set_active(&pdev->dev);
241	pm_runtime_enable(&pdev->dev);
242
243	ret = clk_prepare_enable(data->ipg_clk);
244	if (ret) {
245		dev_err(&pdev->dev, "failed to enable ipg clk: %d\n", ret);
246		return ret;
247	}
248
249	for (i = 0; i < channum; i++) {
250		data->irqchip_data[i].chip = imx_intmux_irq_chip;
251		data->irqchip_data[i].chip.parent_device = &pdev->dev;
252		data->irqchip_data[i].chanidx = i;
253
254		data->irqchip_data[i].irq = irq_of_parse_and_map(np, i);
255		if (data->irqchip_data[i].irq <= 0) {
256			ret = -EINVAL;
257			dev_err(&pdev->dev, "failed to get irq\n");
258			goto out;
259		}
260
261		domain = irq_domain_add_linear(np, 32, &imx_intmux_domain_ops,
262					       &data->irqchip_data[i]);
263		if (!domain) {
264			ret = -ENOMEM;
265			dev_err(&pdev->dev, "failed to create IRQ domain\n");
266			goto out;
267		}
268		data->irqchip_data[i].domain = domain;
269
270		/* disable all interrupt sources of this channel firstly */
271		writel_relaxed(0, data->regs + CHANIER(i));
272
273		irq_set_chained_handler_and_data(data->irqchip_data[i].irq,
274						 imx_intmux_irq_handler,
275						 &data->irqchip_data[i]);
276	}
277
278	platform_set_drvdata(pdev, data);
279
280	/*
281	 * Let pm_runtime_put() disable clock.
282	 * If CONFIG_PM is not enabled, the clock will stay powered.
283	 */
284	pm_runtime_put(&pdev->dev);
285
286	return 0;
287out:
288	clk_disable_unprepare(data->ipg_clk);
289	return ret;
290}
291
292static int imx_intmux_remove(struct platform_device *pdev)
293{
294	struct intmux_data *data = platform_get_drvdata(pdev);
295	int i;
296
297	for (i = 0; i < data->channum; i++) {
298		/* disable all interrupt sources of this channel */
299		writel_relaxed(0, data->regs + CHANIER(i));
300
301		irq_set_chained_handler_and_data(data->irqchip_data[i].irq,
302						 NULL, NULL);
303
304		irq_domain_remove(data->irqchip_data[i].domain);
305	}
306
307	pm_runtime_disable(&pdev->dev);
308
309	return 0;
310}
311
312#ifdef CONFIG_PM
313static int imx_intmux_runtime_suspend(struct device *dev)
314{
315	struct intmux_data *data = dev_get_drvdata(dev);
316	struct intmux_irqchip_data *irqchip_data;
317	int i;
318
319	for (i = 0; i < data->channum; i++) {
320		irqchip_data = &data->irqchip_data[i];
321		irqchip_data->saved_reg = readl_relaxed(data->regs + CHANIER(i));
322	}
323
324	clk_disable_unprepare(data->ipg_clk);
325
326	return 0;
327}
328
329static int imx_intmux_runtime_resume(struct device *dev)
330{
331	struct intmux_data *data = dev_get_drvdata(dev);
332	struct intmux_irqchip_data *irqchip_data;
333	int ret, i;
334
335	ret = clk_prepare_enable(data->ipg_clk);
336	if (ret) {
337		dev_err(dev, "failed to enable ipg clk: %d\n", ret);
338		return ret;
339	}
340
341	for (i = 0; i < data->channum; i++) {
342		irqchip_data = &data->irqchip_data[i];
343		writel_relaxed(irqchip_data->saved_reg, data->regs + CHANIER(i));
344	}
345
346	return 0;
347}
348#endif
349
350static const struct dev_pm_ops imx_intmux_pm_ops = {
351	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
352				      pm_runtime_force_resume)
353	SET_RUNTIME_PM_OPS(imx_intmux_runtime_suspend,
354			   imx_intmux_runtime_resume, NULL)
355};
356
357static const struct of_device_id imx_intmux_id[] = {
358	{ .compatible = "fsl,imx-intmux", },
359	{ /* sentinel */ },
360};
361
362static struct platform_driver imx_intmux_driver = {
363	.driver = {
364		.name = "imx-intmux",
365		.of_match_table = imx_intmux_id,
366		.pm = &imx_intmux_pm_ops,
367	},
368	.probe = imx_intmux_probe,
369	.remove = imx_intmux_remove,
370};
371builtin_platform_driver(imx_intmux_driver);