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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/mod_devicetable.h>
 54#include <linux/of_irq.h>
 55#include <linux/platform_device.h>
 56#include <linux/spinlock.h>
 57#include <linux/pm_runtime.h>
 58
 59#define CHANIER(n)	(0x10 + (0x40 * n))
 60#define CHANIPR(n)	(0x20 + (0x40 * n))
 61
 62#define CHAN_MAX_NUM		0x8
 63
 64struct intmux_irqchip_data {
 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[] __counted_by(channum);
 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 __ro_after_init = {
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, &imx_intmux_irq_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;
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
198static 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].chanidx = i;
245
246		data->irqchip_data[i].irq = irq_of_parse_and_map(np, i);
247		if (data->irqchip_data[i].irq <= 0) {
248			ret = -EINVAL;
249			dev_err(&pdev->dev, "failed to get irq\n");
250			goto out;
251		}
252
253		domain = irq_domain_add_linear(np, 32, &imx_intmux_domain_ops,
254					       &data->irqchip_data[i]);
255		if (!domain) {
256			ret = -ENOMEM;
257			dev_err(&pdev->dev, "failed to create IRQ domain\n");
258			goto out;
259		}
260		data->irqchip_data[i].domain = domain;
261		irq_domain_set_pm_device(domain, &pdev->dev);
262
263		/* disable all interrupt sources of this channel firstly */
264		writel_relaxed(0, data->regs + CHANIER(i));
265
266		irq_set_chained_handler_and_data(data->irqchip_data[i].irq,
267						 imx_intmux_irq_handler,
268						 &data->irqchip_data[i]);
269	}
270
271	platform_set_drvdata(pdev, data);
272
273	/*
274	 * Let pm_runtime_put() disable clock.
275	 * If CONFIG_PM is not enabled, the clock will stay powered.
276	 */
277	pm_runtime_put(&pdev->dev);
278
279	return 0;
280out:
281	clk_disable_unprepare(data->ipg_clk);
282	return ret;
283}
284
285static int imx_intmux_remove(struct platform_device *pdev)
286{
287	struct intmux_data *data = platform_get_drvdata(pdev);
288	int i;
289
290	for (i = 0; i < data->channum; i++) {
291		/* disable all interrupt sources of this channel */
292		writel_relaxed(0, data->regs + CHANIER(i));
293
294		irq_set_chained_handler_and_data(data->irqchip_data[i].irq,
295						 NULL, NULL);
296
297		irq_domain_remove(data->irqchip_data[i].domain);
298	}
299
300	pm_runtime_disable(&pdev->dev);
301
302	return 0;
303}
304
305#ifdef CONFIG_PM
306static int imx_intmux_runtime_suspend(struct device *dev)
307{
308	struct intmux_data *data = dev_get_drvdata(dev);
309	struct intmux_irqchip_data *irqchip_data;
310	int i;
311
312	for (i = 0; i < data->channum; i++) {
313		irqchip_data = &data->irqchip_data[i];
314		irqchip_data->saved_reg = readl_relaxed(data->regs + CHANIER(i));
315	}
316
317	clk_disable_unprepare(data->ipg_clk);
318
319	return 0;
320}
321
322static int imx_intmux_runtime_resume(struct device *dev)
323{
324	struct intmux_data *data = dev_get_drvdata(dev);
325	struct intmux_irqchip_data *irqchip_data;
326	int ret, i;
327
328	ret = clk_prepare_enable(data->ipg_clk);
329	if (ret) {
330		dev_err(dev, "failed to enable ipg clk: %d\n", ret);
331		return ret;
332	}
333
334	for (i = 0; i < data->channum; i++) {
335		irqchip_data = &data->irqchip_data[i];
336		writel_relaxed(irqchip_data->saved_reg, data->regs + CHANIER(i));
337	}
338
339	return 0;
340}
341#endif
342
343static const struct dev_pm_ops imx_intmux_pm_ops = {
344	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
345				      pm_runtime_force_resume)
346	SET_RUNTIME_PM_OPS(imx_intmux_runtime_suspend,
347			   imx_intmux_runtime_resume, NULL)
348};
349
350static const struct of_device_id imx_intmux_id[] = {
351	{ .compatible = "fsl,imx-intmux", },
352	{ /* sentinel */ },
353};
354
355static struct platform_driver imx_intmux_driver = {
356	.driver = {
357		.name = "imx-intmux",
358		.of_match_table = imx_intmux_id,
359		.pm = &imx_intmux_pm_ops,
360	},
361	.probe = imx_intmux_probe,
362	.remove = imx_intmux_remove,
363};
364builtin_platform_driver(imx_intmux_driver);