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  1/*
  2 * Emma Mobile GPIO Support - GIO
  3 *
  4 *  Copyright (C) 2012 Magnus Damm
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License as published by
  8 * the Free Software Foundation; either version 2 of the License
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 *
 15 * You should have received a copy of the GNU General Public License
 16 * along with this program; if not, write to the Free Software
 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 18 */
 19
 20#include <linux/init.h>
 21#include <linux/platform_device.h>
 22#include <linux/spinlock.h>
 23#include <linux/interrupt.h>
 24#include <linux/ioport.h>
 25#include <linux/io.h>
 26#include <linux/irq.h>
 27#include <linux/irqdomain.h>
 28#include <linux/bitops.h>
 29#include <linux/err.h>
 30#include <linux/gpio.h>
 31#include <linux/slab.h>
 32#include <linux/module.h>
 33#include <linux/platform_data/gpio-em.h>
 34
 35struct em_gio_priv {
 36	void __iomem *base0;
 37	void __iomem *base1;
 38	unsigned int irq_base;
 39	spinlock_t sense_lock;
 40	struct platform_device *pdev;
 41	struct gpio_chip gpio_chip;
 42	struct irq_chip irq_chip;
 43	struct irq_domain *irq_domain;
 44};
 45
 46#define GIO_E1 0x00
 47#define GIO_E0 0x04
 48#define GIO_EM 0x04
 49#define GIO_OL 0x08
 50#define GIO_OH 0x0c
 51#define GIO_I 0x10
 52#define GIO_IIA 0x14
 53#define GIO_IEN 0x18
 54#define GIO_IDS 0x1c
 55#define GIO_IIM 0x1c
 56#define GIO_RAW 0x20
 57#define GIO_MST 0x24
 58#define GIO_IIR 0x28
 59
 60#define GIO_IDT0 0x40
 61#define GIO_IDT1 0x44
 62#define GIO_IDT2 0x48
 63#define GIO_IDT3 0x4c
 64#define GIO_RAWBL 0x50
 65#define GIO_RAWBH 0x54
 66#define GIO_IRBL 0x58
 67#define GIO_IRBH 0x5c
 68
 69#define GIO_IDT(n) (GIO_IDT0 + ((n) * 4))
 70
 71static inline unsigned long em_gio_read(struct em_gio_priv *p, int offs)
 72{
 73	if (offs < GIO_IDT0)
 74		return ioread32(p->base0 + offs);
 75	else
 76		return ioread32(p->base1 + (offs - GIO_IDT0));
 77}
 78
 79static inline void em_gio_write(struct em_gio_priv *p, int offs,
 80				unsigned long value)
 81{
 82	if (offs < GIO_IDT0)
 83		iowrite32(value, p->base0 + offs);
 84	else
 85		iowrite32(value, p->base1 + (offs - GIO_IDT0));
 86}
 87
 88static inline struct em_gio_priv *irq_to_priv(struct irq_data *d)
 89{
 90	struct irq_chip *chip = irq_data_get_irq_chip(d);
 91	return container_of(chip, struct em_gio_priv, irq_chip);
 92}
 93
 94static void em_gio_irq_disable(struct irq_data *d)
 95{
 96	struct em_gio_priv *p = irq_to_priv(d);
 97
 98	em_gio_write(p, GIO_IDS, BIT(irqd_to_hwirq(d)));
 99}
100
101static void em_gio_irq_enable(struct irq_data *d)
102{
103	struct em_gio_priv *p = irq_to_priv(d);
104
105	em_gio_write(p, GIO_IEN, BIT(irqd_to_hwirq(d)));
106}
107
108#define GIO_ASYNC(x) (x + 8)
109
110static unsigned char em_gio_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
111	[IRQ_TYPE_EDGE_RISING] = GIO_ASYNC(0x00),
112	[IRQ_TYPE_EDGE_FALLING] = GIO_ASYNC(0x01),
113	[IRQ_TYPE_LEVEL_HIGH] = GIO_ASYNC(0x02),
114	[IRQ_TYPE_LEVEL_LOW] = GIO_ASYNC(0x03),
115	[IRQ_TYPE_EDGE_BOTH] = GIO_ASYNC(0x04),
116};
117
118static int em_gio_irq_set_type(struct irq_data *d, unsigned int type)
119{
120	unsigned char value = em_gio_sense_table[type & IRQ_TYPE_SENSE_MASK];
121	struct em_gio_priv *p = irq_to_priv(d);
122	unsigned int reg, offset, shift;
123	unsigned long flags;
124	unsigned long tmp;
125
126	if (!value)
127		return -EINVAL;
128
129	offset = irqd_to_hwirq(d);
130
131	pr_debug("gio: sense irq = %d, mode = %d\n", offset, value);
132
133	/* 8 x 4 bit fields in 4 IDT registers */
134	reg = GIO_IDT(offset >> 3);
135	shift = (offset & 0x07) << 4;
136
137	spin_lock_irqsave(&p->sense_lock, flags);
138
139	/* disable the interrupt in IIA */
140	tmp = em_gio_read(p, GIO_IIA);
141	tmp &= ~BIT(offset);
142	em_gio_write(p, GIO_IIA, tmp);
143
144	/* change the sense setting in IDT */
145	tmp = em_gio_read(p, reg);
146	tmp &= ~(0xf << shift);
147	tmp |= value << shift;
148	em_gio_write(p, reg, tmp);
149
150	/* clear pending interrupts */
151	em_gio_write(p, GIO_IIR, BIT(offset));
152
153	/* enable the interrupt in IIA */
154	tmp = em_gio_read(p, GIO_IIA);
155	tmp |= BIT(offset);
156	em_gio_write(p, GIO_IIA, tmp);
157
158	spin_unlock_irqrestore(&p->sense_lock, flags);
159
160	return 0;
161}
162
163static irqreturn_t em_gio_irq_handler(int irq, void *dev_id)
164{
165	struct em_gio_priv *p = dev_id;
166	unsigned long pending;
167	unsigned int offset, irqs_handled = 0;
168
169	while ((pending = em_gio_read(p, GIO_MST))) {
170		offset = __ffs(pending);
171		em_gio_write(p, GIO_IIR, BIT(offset));
172		generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
173		irqs_handled++;
174	}
175
176	return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
177}
178
179static inline struct em_gio_priv *gpio_to_priv(struct gpio_chip *chip)
180{
181	return container_of(chip, struct em_gio_priv, gpio_chip);
182}
183
184static int em_gio_direction_input(struct gpio_chip *chip, unsigned offset)
185{
186	em_gio_write(gpio_to_priv(chip), GIO_E0, BIT(offset));
187	return 0;
188}
189
190static int em_gio_get(struct gpio_chip *chip, unsigned offset)
191{
192	return (int)(em_gio_read(gpio_to_priv(chip), GIO_I) & BIT(offset));
193}
194
195static void __em_gio_set(struct gpio_chip *chip, unsigned int reg,
196			 unsigned shift, int value)
197{
198	/* upper 16 bits contains mask and lower 16 actual value */
199	em_gio_write(gpio_to_priv(chip), reg,
200		     (1 << (shift + 16)) | (value << shift));
201}
202
203static void em_gio_set(struct gpio_chip *chip, unsigned offset, int value)
204{
205	/* output is split into two registers */
206	if (offset < 16)
207		__em_gio_set(chip, GIO_OL, offset, value);
208	else
209		__em_gio_set(chip, GIO_OH, offset - 16, value);
210}
211
212static int em_gio_direction_output(struct gpio_chip *chip, unsigned offset,
213				   int value)
214{
215	/* write GPIO value to output before selecting output mode of pin */
216	em_gio_set(chip, offset, value);
217	em_gio_write(gpio_to_priv(chip), GIO_E1, BIT(offset));
218	return 0;
219}
220
221static int em_gio_to_irq(struct gpio_chip *chip, unsigned offset)
222{
223	return irq_find_mapping(gpio_to_priv(chip)->irq_domain, offset);
224}
225
226static int em_gio_irq_domain_map(struct irq_domain *h, unsigned int virq,
227				 irq_hw_number_t hw)
228{
229	struct em_gio_priv *p = h->host_data;
230
231	pr_debug("gio: map hw irq = %d, virq = %d\n", (int)hw, virq);
232
233	irq_set_chip_data(virq, h->host_data);
234	irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
235	set_irq_flags(virq, IRQF_VALID); /* kill me now */
236	return 0;
237}
238
239static struct irq_domain_ops em_gio_irq_domain_ops = {
240	.map	= em_gio_irq_domain_map,
241};
242
243static int __devinit em_gio_irq_domain_init(struct em_gio_priv *p)
244{
245	struct platform_device *pdev = p->pdev;
246	struct gpio_em_config *pdata = pdev->dev.platform_data;
247
248	p->irq_base = irq_alloc_descs(pdata->irq_base, 0,
249				      pdata->number_of_pins, numa_node_id());
250	if (IS_ERR_VALUE(p->irq_base)) {
251		dev_err(&pdev->dev, "cannot get irq_desc\n");
252		return -ENXIO;
253	}
254	pr_debug("gio: hw base = %d, nr = %d, sw base = %d\n",
255		 pdata->gpio_base, pdata->number_of_pins, p->irq_base);
256
257	p->irq_domain = irq_domain_add_legacy(pdev->dev.of_node,
258					      pdata->number_of_pins,
259					      p->irq_base, 0,
260					      &em_gio_irq_domain_ops, p);
261	if (!p->irq_domain) {
262		irq_free_descs(p->irq_base, pdata->number_of_pins);
263		return -ENXIO;
264	}
265
266	return 0;
267}
268
269static void __devexit em_gio_irq_domain_cleanup(struct em_gio_priv *p)
270{
271	struct gpio_em_config *pdata = p->pdev->dev.platform_data;
272
273	irq_free_descs(p->irq_base, pdata->number_of_pins);
274	/* FIXME: irq domain wants to be freed! */
275}
276
277static int __devinit em_gio_probe(struct platform_device *pdev)
278{
279	struct gpio_em_config *pdata = pdev->dev.platform_data;
280	struct em_gio_priv *p;
281	struct resource *io[2], *irq[2];
282	struct gpio_chip *gpio_chip;
283	struct irq_chip *irq_chip;
284	const char *name = dev_name(&pdev->dev);
285	int ret;
286
287	p = kzalloc(sizeof(*p), GFP_KERNEL);
288	if (!p) {
289		dev_err(&pdev->dev, "failed to allocate driver data\n");
290		ret = -ENOMEM;
291		goto err0;
292	}
293
294	p->pdev = pdev;
295	platform_set_drvdata(pdev, p);
296	spin_lock_init(&p->sense_lock);
297
298	io[0] = platform_get_resource(pdev, IORESOURCE_MEM, 0);
299	io[1] = platform_get_resource(pdev, IORESOURCE_MEM, 1);
300	irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
301	irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
302
303	if (!io[0] || !io[1] || !irq[0] || !irq[1] || !pdata) {
304		dev_err(&pdev->dev, "missing IRQ, IOMEM or configuration\n");
305		ret = -EINVAL;
306		goto err1;
307	}
308
309	p->base0 = ioremap_nocache(io[0]->start, resource_size(io[0]));
310	if (!p->base0) {
311		dev_err(&pdev->dev, "failed to remap low I/O memory\n");
312		ret = -ENXIO;
313		goto err1;
314	}
315
316	p->base1 = ioremap_nocache(io[1]->start, resource_size(io[1]));
317	if (!p->base1) {
318		dev_err(&pdev->dev, "failed to remap high I/O memory\n");
319		ret = -ENXIO;
320		goto err2;
321	}
322
323	gpio_chip = &p->gpio_chip;
324	gpio_chip->direction_input = em_gio_direction_input;
325	gpio_chip->get = em_gio_get;
326	gpio_chip->direction_output = em_gio_direction_output;
327	gpio_chip->set = em_gio_set;
328	gpio_chip->to_irq = em_gio_to_irq;
329	gpio_chip->label = name;
330	gpio_chip->owner = THIS_MODULE;
331	gpio_chip->base = pdata->gpio_base;
332	gpio_chip->ngpio = pdata->number_of_pins;
333
334	irq_chip = &p->irq_chip;
335	irq_chip->name = name;
336	irq_chip->irq_mask = em_gio_irq_disable;
337	irq_chip->irq_unmask = em_gio_irq_enable;
338	irq_chip->irq_enable = em_gio_irq_enable;
339	irq_chip->irq_disable = em_gio_irq_disable;
340	irq_chip->irq_set_type = em_gio_irq_set_type;
341	irq_chip->flags	= IRQCHIP_SKIP_SET_WAKE;
342
343	ret = em_gio_irq_domain_init(p);
344	if (ret) {
345		dev_err(&pdev->dev, "cannot initialize irq domain\n");
346		goto err3;
347	}
348
349	if (request_irq(irq[0]->start, em_gio_irq_handler, 0, name, p)) {
350		dev_err(&pdev->dev, "failed to request low IRQ\n");
351		ret = -ENOENT;
352		goto err4;
353	}
354
355	if (request_irq(irq[1]->start, em_gio_irq_handler, 0, name, p)) {
356		dev_err(&pdev->dev, "failed to request high IRQ\n");
357		ret = -ENOENT;
358		goto err5;
359	}
360
361	ret = gpiochip_add(gpio_chip);
362	if (ret) {
363		dev_err(&pdev->dev, "failed to add GPIO controller\n");
364		goto err6;
365	}
366	return 0;
367
368err6:
369	free_irq(irq[1]->start, pdev);
370err5:
371	free_irq(irq[0]->start, pdev);
372err4:
373	em_gio_irq_domain_cleanup(p);
374err3:
375	iounmap(p->base1);
376err2:
377	iounmap(p->base0);
378err1:
379	kfree(p);
380err0:
381	return ret;
382}
383
384static int __devexit em_gio_remove(struct platform_device *pdev)
385{
386	struct em_gio_priv *p = platform_get_drvdata(pdev);
387	struct resource *irq[2];
388	int ret;
389
390	ret = gpiochip_remove(&p->gpio_chip);
391	if (ret)
392		return ret;
393
394	irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
395	irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
396
397	free_irq(irq[1]->start, pdev);
398	free_irq(irq[0]->start, pdev);
399	em_gio_irq_domain_cleanup(p);
400	iounmap(p->base1);
401	iounmap(p->base0);
402	kfree(p);
403	return 0;
404}
405
406static struct platform_driver em_gio_device_driver = {
407	.probe		= em_gio_probe,
408	.remove		= __devexit_p(em_gio_remove),
409	.driver		= {
410		.name	= "em_gio",
411	}
412};
413
414module_platform_driver(em_gio_device_driver);
415
416MODULE_AUTHOR("Magnus Damm");
417MODULE_DESCRIPTION("Renesas Emma Mobile GIO Driver");
418MODULE_LICENSE("GPL v2");