summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/langwell_gpio.c
blob: 8383a8d7f9945dee14f15fb6b4ba3c08a3885fe6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
/* langwell_gpio.c Moorestown platform Langwell chip GPIO driver
 * Copyright (c) 2008 - 2009,  Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* Supports:
 * Moorestown platform Langwell chip.
 * Medfield platform Penwell chip.
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/stddef.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/slab.h>

/*
 * Langwell chip has 64 pins and thus there are 2 32bit registers to control
 * each feature, while Penwell chip has 96 pins for each block, and need 3 32bit
 * registers to control them, so we only define the order here instead of a
 * structure, to get a bit offset for a pin (use GPDR as an example):
 *
 * nreg = ngpio / 32;
 * reg = offset / 32;
 * bit = offset % 32;
 * reg_addr = reg_base + GPDR * nreg * 4 + reg * 4;
 *
 * so the bit of reg_addr is to control pin offset's GPDR feature
*/

enum GPIO_REG {
	GPLR = 0,	/* pin level read-only */
	GPDR,		/* pin direction */
	GPSR,		/* pin set */
	GPCR,		/* pin clear */
	GRER,		/* rising edge detect */
	GFER,		/* falling edge detect */
	GEDR,		/* edge detect result */
};

struct lnw_gpio {
	struct gpio_chip		chip;
	void				*reg_base;
	spinlock_t			lock;
	unsigned			irq_base;
};

static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned offset,
			enum GPIO_REG reg_type)
{
	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
	unsigned nreg = chip->ngpio / 32;
	u8 reg = offset / 32;
	void __iomem *ptr;

	ptr = (void __iomem *)(lnw->reg_base + reg_type * nreg * 4 + reg * 4);
	return ptr;
}

static int lnw_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	void __iomem *gplr = gpio_reg(chip, offset, GPLR);

	return readl(gplr) & BIT(offset % 32);
}

static void lnw_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	void __iomem *gpsr, *gpcr;

	if (value) {
		gpsr = gpio_reg(chip, offset, GPSR);
		writel(BIT(offset % 32), gpsr);
	} else {
		gpcr = gpio_reg(chip, offset, GPCR);
		writel(BIT(offset % 32), gpcr);
	}
}

static int lnw_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
	void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
	u32 value;
	unsigned long flags;

	spin_lock_irqsave(&lnw->lock, flags);
	value = readl(gpdr);
	value &= ~BIT(offset % 32);
	writel(value, gpdr);
	spin_unlock_irqrestore(&lnw->lock, flags);
	return 0;
}

static int lnw_gpio_direction_output(struct gpio_chip *chip,
			unsigned offset, int value)
{
	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
	void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
	unsigned long flags;

	lnw_gpio_set(chip, offset, value);
	spin_lock_irqsave(&lnw->lock, flags);
	value = readl(gpdr);
	value |= BIT(offset % 32);;
	writel(value, gpdr);
	spin_unlock_irqrestore(&lnw->lock, flags);
	return 0;
}

static int lnw_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
	return lnw->irq_base + offset;
}

static int lnw_irq_type(unsigned irq, unsigned type)
{
	struct lnw_gpio *lnw = get_irq_chip_data(irq);
	u32 gpio = irq - lnw->irq_base;
	unsigned long flags;
	u32 value;
	void __iomem *grer = gpio_reg(&lnw->chip, gpio, GRER);
	void __iomem *gfer = gpio_reg(&lnw->chip, gpio, GFER);

	if (gpio >= lnw->chip.ngpio)
		return -EINVAL;
	spin_lock_irqsave(&lnw->lock, flags);
	if (type & IRQ_TYPE_EDGE_RISING)
		value = readl(grer) | BIT(gpio % 32);
	else
		value = readl(grer) & (~BIT(gpio % 32));
	writel(value, grer);

	if (type & IRQ_TYPE_EDGE_FALLING)
		value = readl(gfer) | BIT(gpio % 32);
	else
		value = readl(gfer) & (~BIT(gpio % 32));
	writel(value, gfer);
	spin_unlock_irqrestore(&lnw->lock, flags);

	return 0;
};

static void lnw_irq_unmask(unsigned irq)
{
};

static void lnw_irq_mask(unsigned irq)
{
};

static struct irq_chip lnw_irqchip = {
	.name		= "LNW-GPIO",
	.mask		= lnw_irq_mask,
	.unmask		= lnw_irq_unmask,
	.set_type	= lnw_irq_type,
};

static DEFINE_PCI_DEVICE_TABLE(lnw_gpio_ids) = {   /* pin number */
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080f), .driver_data = 64 },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081f), .driver_data = 96 },
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081a), .driver_data = 96 },
	{ 0, }
};
MODULE_DEVICE_TABLE(pci, lnw_gpio_ids);

static void lnw_irq_handler(unsigned irq, struct irq_desc *desc)
{
	struct lnw_gpio *lnw = (struct lnw_gpio *)get_irq_data(irq);
	u32 base, gpio;
	void __iomem *gedr;
	u32 gedr_v;

	/* check GPIO controller to check which pin triggered the interrupt */
	for (base = 0; base < lnw->chip.ngpio; base += 32) {
		gedr = gpio_reg(&lnw->chip, base, GEDR);
		gedr_v = readl(gedr);
		if (!gedr_v)
			continue;
		for (gpio = base; gpio < base + 32; gpio++)
			if (gedr_v & BIT(gpio % 32)) {
				pr_debug("pin %d triggered\n", gpio);
				generic_handle_irq(lnw->irq_base + gpio);
			}
		/* clear the edge detect status bit */
		writel(gedr_v, gedr);
	}
	desc->chip->eoi(irq);
}

static int __devinit lnw_gpio_probe(struct pci_dev *pdev,
			const struct pci_device_id *id)
{
	void *base;
	int i;
	resource_size_t start, len;
	struct lnw_gpio *lnw;
	u32 irq_base;
	u32 gpio_base;
	int retval = 0;

	retval = pci_enable_device(pdev);
	if (retval)
		goto done;

	retval = pci_request_regions(pdev, "langwell_gpio");
	if (retval) {
		dev_err(&pdev->dev, "error requesting resources\n");
		goto err2;
	}
	/* get the irq_base from bar1 */
	start = pci_resource_start(pdev, 1);
	len = pci_resource_len(pdev, 1);
	base = ioremap_nocache(start, len);
	if (!base) {
		dev_err(&pdev->dev, "error mapping bar1\n");
		goto err3;
	}
	irq_base = *(u32 *)base;
	gpio_base = *((u32 *)base + 1);
	/* release the IO mapping, since we already get the info from bar1 */
	iounmap(base);
	/* get the register base from bar0 */
	start = pci_resource_start(pdev, 0);
	len = pci_resource_len(pdev, 0);
	base = ioremap_nocache(start, len);
	if (!base) {
		dev_err(&pdev->dev, "error mapping bar0\n");
		retval = -EFAULT;
		goto err3;
	}

	lnw = kzalloc(sizeof(struct lnw_gpio), GFP_KERNEL);
	if (!lnw) {
		dev_err(&pdev->dev, "can't allocate langwell_gpio chip data\n");
		retval = -ENOMEM;
		goto err4;
	}
	lnw->reg_base = base;
	lnw->irq_base = irq_base;
	lnw->chip.label = dev_name(&pdev->dev);
	lnw->chip.direction_input = lnw_gpio_direction_input;
	lnw->chip.direction_output = lnw_gpio_direction_output;
	lnw->chip.get = lnw_gpio_get;
	lnw->chip.set = lnw_gpio_set;
	lnw->chip.to_irq = lnw_gpio_to_irq;
	lnw->chip.base = gpio_base;
	lnw->chip.ngpio = id->driver_data;
	lnw->chip.can_sleep = 0;
	pci_set_drvdata(pdev, lnw);
	retval = gpiochip_add(&lnw->chip);
	if (retval) {
		dev_err(&pdev->dev, "langwell gpiochip_add error %d\n", retval);
		goto err5;
	}
	set_irq_data(pdev->irq, lnw);
	set_irq_chained_handler(pdev->irq, lnw_irq_handler);
	for (i = 0; i < lnw->chip.ngpio; i++) {
		set_irq_chip_and_handler_name(i + lnw->irq_base, &lnw_irqchip,
					handle_simple_irq, "demux");
		set_irq_chip_data(i + lnw->irq_base, lnw);
	}

	spin_lock_init(&lnw->lock);
	goto done;
err5:
	kfree(lnw);
err4:
	iounmap(base);
err3:
	pci_release_regions(pdev);
err2:
	pci_disable_device(pdev);
done:
	return retval;
}

static struct pci_driver lnw_gpio_driver = {
	.name		= "langwell_gpio",
	.id_table	= lnw_gpio_ids,
	.probe		= lnw_gpio_probe,
};

static int __init lnw_gpio_init(void)
{
	return pci_register_driver(&lnw_gpio_driver);
}

device_initcall(lnw_gpio_init);