1/*
2 * IMG PowerDown Controller (PDC)
3 *
4 * Copyright 2010-2013 Imagination Technologies Ltd.
5 *
6 * Exposes the syswake and PDC peripheral wake interrupts to the system.
7 *
8 */
9
10#include <linux/bitops.h>
11#include <linux/interrupt.h>
12#include <linux/irqdomain.h>
13#include <linux/io.h>
14#include <linux/kernel.h>
15#include <linux/of.h>
16#include <linux/platform_device.h>
17#include <linux/spinlock.h>
18
19/* PDC interrupt register numbers */
20
21#define PDC_IRQ_STATUS			0x310
22#define PDC_IRQ_ENABLE			0x314
23#define PDC_IRQ_CLEAR			0x318
24#define PDC_IRQ_ROUTE			0x31c
25#define PDC_SYS_WAKE_BASE		0x330
26#define PDC_SYS_WAKE_STRIDE		0x8
27#define PDC_SYS_WAKE_CONFIG_BASE	0x334
28#define PDC_SYS_WAKE_CONFIG_STRIDE	0x8
29
30/* PDC interrupt register field masks */
31
32#define PDC_IRQ_SYS3			0x08
33#define PDC_IRQ_SYS2			0x04
34#define PDC_IRQ_SYS1			0x02
35#define PDC_IRQ_SYS0			0x01
36#define PDC_IRQ_ROUTE_WU_EN_SYS3	0x08000000
37#define PDC_IRQ_ROUTE_WU_EN_SYS2	0x04000000
38#define PDC_IRQ_ROUTE_WU_EN_SYS1	0x02000000
39#define PDC_IRQ_ROUTE_WU_EN_SYS0	0x01000000
40#define PDC_IRQ_ROUTE_WU_EN_WD		0x00040000
41#define PDC_IRQ_ROUTE_WU_EN_IR		0x00020000
42#define PDC_IRQ_ROUTE_WU_EN_RTC		0x00010000
43#define PDC_IRQ_ROUTE_EXT_EN_SYS3	0x00000800
44#define PDC_IRQ_ROUTE_EXT_EN_SYS2	0x00000400
45#define PDC_IRQ_ROUTE_EXT_EN_SYS1	0x00000200
46#define PDC_IRQ_ROUTE_EXT_EN_SYS0	0x00000100
47#define PDC_IRQ_ROUTE_EXT_EN_WD		0x00000004
48#define PDC_IRQ_ROUTE_EXT_EN_IR		0x00000002
49#define PDC_IRQ_ROUTE_EXT_EN_RTC	0x00000001
50#define PDC_SYS_WAKE_RESET		0x00000010
51#define PDC_SYS_WAKE_INT_MODE		0x0000000e
52#define PDC_SYS_WAKE_INT_MODE_SHIFT	1
53#define PDC_SYS_WAKE_PIN_VAL		0x00000001
54
55/* PDC interrupt constants */
56
57#define PDC_SYS_WAKE_INT_LOW		0x0
58#define PDC_SYS_WAKE_INT_HIGH		0x1
59#define PDC_SYS_WAKE_INT_DOWN		0x2
60#define PDC_SYS_WAKE_INT_UP		0x3
61#define PDC_SYS_WAKE_INT_CHANGE		0x6
62#define PDC_SYS_WAKE_INT_NONE		0x4
63
64/**
65 * struct pdc_intc_priv - private pdc interrupt data.
66 * @nr_perips:		Number of peripheral interrupt signals.
67 * @nr_syswakes:	Number of syswake signals.
68 * @perip_irqs:		List of peripheral IRQ numbers handled.
69 * @syswake_irq:	Shared PDC syswake IRQ number.
70 * @domain:		IRQ domain for PDC peripheral and syswake IRQs.
71 * @pdc_base:		Base of PDC registers.
72 * @irq_route:		Cached version of PDC_IRQ_ROUTE register.
73 * @lock:		Lock to protect the PDC syswake registers and the cached
74 *			values of those registers in this struct.
75 */
76struct pdc_intc_priv {
77	unsigned int		nr_perips;
78	unsigned int		nr_syswakes;
79	unsigned int		*perip_irqs;
80	unsigned int		syswake_irq;
81	struct irq_domain	*domain;
82	void __iomem		*pdc_base;
83
84	u32			irq_route;
85	raw_spinlock_t		lock;
86};
87
88static void pdc_write(struct pdc_intc_priv *priv, unsigned int reg_offs,
89		      unsigned int data)
90{
91	iowrite32(data, priv->pdc_base + reg_offs);
92}
93
94static unsigned int pdc_read(struct pdc_intc_priv *priv,
95			     unsigned int reg_offs)
96{
97	return ioread32(priv->pdc_base + reg_offs);
98}
99
100/* Generic IRQ callbacks */
101
102#define SYS0_HWIRQ	8
103
104static unsigned int hwirq_is_syswake(irq_hw_number_t hw)
105{
106	return hw >= SYS0_HWIRQ;
107}
108
109static unsigned int hwirq_to_syswake(irq_hw_number_t hw)
110{
111	return hw - SYS0_HWIRQ;
112}
113
114static irq_hw_number_t syswake_to_hwirq(unsigned int syswake)
115{
116	return SYS0_HWIRQ + syswake;
117}
118
119static struct pdc_intc_priv *irqd_to_priv(struct irq_data *data)
120{
121	return (struct pdc_intc_priv *)data->domain->host_data;
122}
123
124/*
125 * perip_irq_mask() and perip_irq_unmask() use IRQ_ROUTE which also contains
126 * wake bits, therefore we cannot use the generic irqchip mask callbacks as they
127 * cache the mask.
128 */
129
130static void perip_irq_mask(struct irq_data *data)
131{
132	struct pdc_intc_priv *priv = irqd_to_priv(data);
133
134	raw_spin_lock(&priv->lock);
135	priv->irq_route &= ~data->mask;
136	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
137	raw_spin_unlock(&priv->lock);
138}
139
140static void perip_irq_unmask(struct irq_data *data)
141{
142	struct pdc_intc_priv *priv = irqd_to_priv(data);
143
144	raw_spin_lock(&priv->lock);
145	priv->irq_route |= data->mask;
146	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
147	raw_spin_unlock(&priv->lock);
148}
149
150static int syswake_irq_set_type(struct irq_data *data, unsigned int flow_type)
151{
152	struct pdc_intc_priv *priv = irqd_to_priv(data);
153	unsigned int syswake = hwirq_to_syswake(data->hwirq);
154	unsigned int irq_mode;
155	unsigned int soc_sys_wake_regoff, soc_sys_wake;
156
157	/* translate to syswake IRQ mode */
158	switch (flow_type) {
159	case IRQ_TYPE_EDGE_BOTH:
160		irq_mode = PDC_SYS_WAKE_INT_CHANGE;
161		break;
162	case IRQ_TYPE_EDGE_RISING:
163		irq_mode = PDC_SYS_WAKE_INT_UP;
164		break;
165	case IRQ_TYPE_EDGE_FALLING:
166		irq_mode = PDC_SYS_WAKE_INT_DOWN;
167		break;
168	case IRQ_TYPE_LEVEL_HIGH:
169		irq_mode = PDC_SYS_WAKE_INT_HIGH;
170		break;
171	case IRQ_TYPE_LEVEL_LOW:
172		irq_mode = PDC_SYS_WAKE_INT_LOW;
173		break;
174	default:
175		return -EINVAL;
176	}
177
178	raw_spin_lock(&priv->lock);
179
180	/* set the IRQ mode */
181	soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + syswake*PDC_SYS_WAKE_STRIDE;
182	soc_sys_wake = pdc_read(priv, soc_sys_wake_regoff);
183	soc_sys_wake &= ~PDC_SYS_WAKE_INT_MODE;
184	soc_sys_wake |= irq_mode << PDC_SYS_WAKE_INT_MODE_SHIFT;
185	pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);
186
187	/* and update the handler */
188	irq_setup_alt_chip(data, flow_type);
189
190	raw_spin_unlock(&priv->lock);
191
192	return 0;
193}
194
195/* applies to both peripheral and syswake interrupts */
196static int pdc_irq_set_wake(struct irq_data *data, unsigned int on)
197{
198	struct pdc_intc_priv *priv = irqd_to_priv(data);
199	irq_hw_number_t hw = data->hwirq;
200	unsigned int mask = (1 << 16) << hw;
201	unsigned int dst_irq;
202
203	raw_spin_lock(&priv->lock);
204	if (on)
205		priv->irq_route |= mask;
206	else
207		priv->irq_route &= ~mask;
208	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
209	raw_spin_unlock(&priv->lock);
210
211	/* control the destination IRQ wakeup too for standby mode */
212	if (hwirq_is_syswake(hw))
213		dst_irq = priv->syswake_irq;
214	else
215		dst_irq = priv->perip_irqs[hw];
216	irq_set_irq_wake(dst_irq, on);
217
218	return 0;
219}
220
221static void pdc_intc_perip_isr(unsigned int irq, struct irq_desc *desc)
222{
223	struct pdc_intc_priv *priv;
224	unsigned int i, irq_no;
225
226	priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);
227
228	/* find the peripheral number */
229	for (i = 0; i < priv->nr_perips; ++i)
230		if (irq == priv->perip_irqs[i])
231			goto found;
232
233	/* should never get here */
234	return;
235found:
236
237	/* pass on the interrupt */
238	irq_no = irq_linear_revmap(priv->domain, i);
239	generic_handle_irq(irq_no);
240}
241
242static void pdc_intc_syswake_isr(unsigned int irq, struct irq_desc *desc)
243{
244	struct pdc_intc_priv *priv;
245	unsigned int syswake, irq_no;
246	unsigned int status;
247
248	priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);
249
250	status = pdc_read(priv, PDC_IRQ_STATUS) &
251		 pdc_read(priv, PDC_IRQ_ENABLE);
252	status &= (1 << priv->nr_syswakes) - 1;
253
254	for (syswake = 0; status; status >>= 1, ++syswake) {
255		/* Has this sys_wake triggered? */
256		if (!(status & 1))
257			continue;
258
259		irq_no = irq_linear_revmap(priv->domain,
260					   syswake_to_hwirq(syswake));
261		generic_handle_irq(irq_no);
262	}
263}
264
265static void pdc_intc_setup(struct pdc_intc_priv *priv)
266{
267	int i;
268	unsigned int soc_sys_wake_regoff;
269	unsigned int soc_sys_wake;
270
271	/*
272	 * Mask all syswake interrupts before routing, or we could receive an
273	 * interrupt before we're ready to handle it.
274	 */
275	pdc_write(priv, PDC_IRQ_ENABLE, 0);
276
277	/*
278	 * Enable routing of all syswakes
279	 * Disable all wake sources
280	 */
281	priv->irq_route = ((PDC_IRQ_ROUTE_EXT_EN_SYS0 << priv->nr_syswakes) -
282				PDC_IRQ_ROUTE_EXT_EN_SYS0);
283	pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
284
285	/* Initialise syswake IRQ */
286	for (i = 0; i < priv->nr_syswakes; ++i) {
287		/* set the IRQ mode to none */
288		soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + i*PDC_SYS_WAKE_STRIDE;
289		soc_sys_wake = PDC_SYS_WAKE_INT_NONE
290				<< PDC_SYS_WAKE_INT_MODE_SHIFT;
291		pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);
292	}
293}
294
295static int pdc_intc_probe(struct platform_device *pdev)
296{
297	struct pdc_intc_priv *priv;
298	struct device_node *node = pdev->dev.of_node;
299	struct resource *res_regs;
300	struct irq_chip_generic *gc;
301	unsigned int i;
302	int irq, ret;
303	u32 val;
304
305	if (!node)
306		return -ENOENT;
307
308	/* Get registers */
309	res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
310	if (res_regs == NULL) {
311		dev_err(&pdev->dev, "cannot find registers resource\n");
312		return -ENOENT;
313	}
314
315	/* Allocate driver data */
316	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
317	if (!priv) {
318		dev_err(&pdev->dev, "cannot allocate device data\n");
319		return -ENOMEM;
320	}
321	raw_spin_lock_init(&priv->lock);
322	platform_set_drvdata(pdev, priv);
323
324	/* Ioremap the registers */
325	priv->pdc_base = devm_ioremap(&pdev->dev, res_regs->start,
326				      res_regs->end - res_regs->start);
327	if (!priv->pdc_base)
328		return -EIO;
329
330	/* Get number of peripherals */
331	ret = of_property_read_u32(node, "num-perips", &val);
332	if (ret) {
333		dev_err(&pdev->dev, "No num-perips node property found\n");
334		return -EINVAL;
335	}
336	if (val > SYS0_HWIRQ) {
337		dev_err(&pdev->dev, "num-perips (%u) out of range\n", val);
338		return -EINVAL;
339	}
340	priv->nr_perips = val;
341
342	/* Get number of syswakes */
343	ret = of_property_read_u32(node, "num-syswakes", &val);
344	if (ret) {
345		dev_err(&pdev->dev, "No num-syswakes node property found\n");
346		return -EINVAL;
347	}
348	if (val > SYS0_HWIRQ) {
349		dev_err(&pdev->dev, "num-syswakes (%u) out of range\n", val);
350		return -EINVAL;
351	}
352	priv->nr_syswakes = val;
353
354	/* Get peripheral IRQ numbers */
355	priv->perip_irqs = devm_kzalloc(&pdev->dev, 4 * priv->nr_perips,
356					GFP_KERNEL);
357	if (!priv->perip_irqs) {
358		dev_err(&pdev->dev, "cannot allocate perip IRQ list\n");
359		return -ENOMEM;
360	}
361	for (i = 0; i < priv->nr_perips; ++i) {
362		irq = platform_get_irq(pdev, 1 + i);
363		if (irq < 0) {
364			dev_err(&pdev->dev, "cannot find perip IRQ #%u\n", i);
365			return irq;
366		}
367		priv->perip_irqs[i] = irq;
368	}
369	/* check if too many were provided */
370	if (platform_get_irq(pdev, 1 + i) >= 0) {
371		dev_err(&pdev->dev, "surplus perip IRQs detected\n");
372		return -EINVAL;
373	}
374
375	/* Get syswake IRQ number */
376	irq = platform_get_irq(pdev, 0);
377	if (irq < 0) {
378		dev_err(&pdev->dev, "cannot find syswake IRQ\n");
379		return irq;
380	}
381	priv->syswake_irq = irq;
382
383	/* Set up an IRQ domain */
384	priv->domain = irq_domain_add_linear(node, 16, &irq_generic_chip_ops,
385					     priv);
386	if (unlikely(!priv->domain)) {
387		dev_err(&pdev->dev, "cannot add IRQ domain\n");
388		return -ENOMEM;
389	}
390
391	/*
392	 * Set up 2 generic irq chips with 2 chip types.
393	 * The first one for peripheral irqs (only 1 chip type used)
394	 * The second one for syswake irqs (edge and level chip types)
395	 */
396	ret = irq_alloc_domain_generic_chips(priv->domain, 8, 2, "pdc",
397					     handle_level_irq, 0, 0,
398					     IRQ_GC_INIT_NESTED_LOCK);
399	if (ret)
400		goto err_generic;
401
402	/* peripheral interrupt chip */
403
404	gc = irq_get_domain_generic_chip(priv->domain, 0);
405	gc->unused	= ~(BIT(priv->nr_perips) - 1);
406	gc->reg_base	= priv->pdc_base;
407	/*
408	 * IRQ_ROUTE contains wake bits, so we can't use the generic versions as
409	 * they cache the mask
410	 */
411	gc->chip_types[0].regs.mask		= PDC_IRQ_ROUTE;
412	gc->chip_types[0].chip.irq_mask		= perip_irq_mask;
413	gc->chip_types[0].chip.irq_unmask	= perip_irq_unmask;
414	gc->chip_types[0].chip.irq_set_wake	= pdc_irq_set_wake;
415
416	/* syswake interrupt chip */
417
418	gc = irq_get_domain_generic_chip(priv->domain, 8);
419	gc->unused	= ~(BIT(priv->nr_syswakes) - 1);
420	gc->reg_base	= priv->pdc_base;
421
422	/* edge interrupts */
423	gc->chip_types[0].type			= IRQ_TYPE_EDGE_BOTH;
424	gc->chip_types[0].handler		= handle_edge_irq;
425	gc->chip_types[0].regs.ack		= PDC_IRQ_CLEAR;
426	gc->chip_types[0].regs.mask		= PDC_IRQ_ENABLE;
427	gc->chip_types[0].chip.irq_ack		= irq_gc_ack_set_bit;
428	gc->chip_types[0].chip.irq_mask		= irq_gc_mask_clr_bit;
429	gc->chip_types[0].chip.irq_unmask	= irq_gc_mask_set_bit;
430	gc->chip_types[0].chip.irq_set_type	= syswake_irq_set_type;
431	gc->chip_types[0].chip.irq_set_wake	= pdc_irq_set_wake;
432	/* for standby we pass on to the shared syswake IRQ */
433	gc->chip_types[0].chip.flags		= IRQCHIP_MASK_ON_SUSPEND;
434
435	/* level interrupts */
436	gc->chip_types[1].type			= IRQ_TYPE_LEVEL_MASK;
437	gc->chip_types[1].handler		= handle_level_irq;
438	gc->chip_types[1].regs.ack		= PDC_IRQ_CLEAR;
439	gc->chip_types[1].regs.mask		= PDC_IRQ_ENABLE;
440	gc->chip_types[1].chip.irq_ack		= irq_gc_ack_set_bit;
441	gc->chip_types[1].chip.irq_mask		= irq_gc_mask_clr_bit;
442	gc->chip_types[1].chip.irq_unmask	= irq_gc_mask_set_bit;
443	gc->chip_types[1].chip.irq_set_type	= syswake_irq_set_type;
444	gc->chip_types[1].chip.irq_set_wake	= pdc_irq_set_wake;
445	/* for standby we pass on to the shared syswake IRQ */
446	gc->chip_types[1].chip.flags		= IRQCHIP_MASK_ON_SUSPEND;
447
448	/* Set up the hardware to enable interrupt routing */
449	pdc_intc_setup(priv);
450
451	/* Setup chained handlers for the peripheral IRQs */
452	for (i = 0; i < priv->nr_perips; ++i) {
453		irq = priv->perip_irqs[i];
454		irq_set_handler_data(irq, priv);
455		irq_set_chained_handler(irq, pdc_intc_perip_isr);
456	}
457
458	/* Setup chained handler for the syswake IRQ */
459	irq_set_handler_data(priv->syswake_irq, priv);
460	irq_set_chained_handler(priv->syswake_irq, pdc_intc_syswake_isr);
461
462	dev_info(&pdev->dev,
463		 "PDC IRQ controller initialised (%u perip IRQs, %u syswake IRQs)\n",
464		 priv->nr_perips,
465		 priv->nr_syswakes);
466
467	return 0;
468err_generic:
469	irq_domain_remove(priv->domain);
470	return ret;
471}
472
473static int pdc_intc_remove(struct platform_device *pdev)
474{
475	struct pdc_intc_priv *priv = platform_get_drvdata(pdev);
476
477	irq_domain_remove(priv->domain);
478	return 0;
479}
480
481static const struct of_device_id pdc_intc_match[] = {
482	{ .compatible = "img,pdc-intc" },
483	{}
484};
485
486static struct platform_driver pdc_intc_driver = {
487	.driver = {
488		.name		= "pdc-intc",
489		.of_match_table	= pdc_intc_match,
490	},
491	.probe = pdc_intc_probe,
492	.remove = pdc_intc_remove,
493};
494
495static int __init pdc_intc_init(void)
496{
497	return platform_driver_register(&pdc_intc_driver);
498}
499core_initcall(pdc_intc_init);
500