1 /*
2 * GPIO controller driver for Intel Lynxpoint PCH chipset>
3 * Copyright (c) 2012, Intel Corporation.
4 *
5 * Author: Mathias Nyman <mathias.nyman@linux.intel.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 */
21
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/types.h>
26 #include <linux/bitops.h>
27 #include <linux/interrupt.h>
28 #include <linux/irq.h>
29 #include <linux/gpio.h>
30 #include <linux/irqdomain.h>
31 #include <linux/slab.h>
32 #include <linux/acpi.h>
33 #include <linux/platform_device.h>
34 #include <linux/pm_runtime.h>
35 #include <linux/io.h>
36
37 /* LynxPoint chipset has support for 94 gpio pins */
38
39 #define LP_NUM_GPIO 94
40
41 /* Bitmapped register offsets */
42 #define LP_ACPI_OWNED 0x00 /* Bitmap, set by bios, 0: pin reserved for ACPI */
43 #define LP_GC 0x7C /* set APIC IRQ to IRQ14 or IRQ15 for all pins */
44 #define LP_INT_STAT 0x80
45 #define LP_INT_ENABLE 0x90
46
47 /* Each pin has two 32 bit config registers, starting at 0x100 */
48 #define LP_CONFIG1 0x100
49 #define LP_CONFIG2 0x104
50
51 /* LP_CONFIG1 reg bits */
52 #define OUT_LVL_BIT BIT(31)
53 #define IN_LVL_BIT BIT(30)
54 #define TRIG_SEL_BIT BIT(4) /* 0: Edge, 1: Level */
55 #define INT_INV_BIT BIT(3) /* Invert interrupt triggering */
56 #define DIR_BIT BIT(2) /* 0: Output, 1: Input */
57 #define USE_SEL_BIT BIT(0) /* 0: Native, 1: GPIO */
58
59 /* LP_CONFIG2 reg bits */
60 #define GPINDIS_BIT BIT(2) /* disable input sensing */
61 #define GPIWP_BIT (BIT(0) | BIT(1)) /* weak pull options */
62
63 struct lp_gpio {
64 struct gpio_chip chip;
65 struct irq_domain *domain;
66 struct platform_device *pdev;
67 spinlock_t lock;
68 unsigned long reg_base;
69 };
70
71 /*
72 * Lynxpoint gpios are controlled through both bitmapped registers and
73 * per gpio specific registers. The bitmapped registers are in chunks of
74 * 3 x 32bit registers to cover all 94 gpios
75 *
76 * per gpio specific registers consist of two 32bit registers per gpio
77 * (LP_CONFIG1 and LP_CONFIG2), with 94 gpios there's a total of
78 * 188 config registes.
79 *
80 * A simplified view of the register layout look like this:
81 *
82 * LP_ACPI_OWNED[31:0] gpio ownerships for gpios 0-31 (bitmapped registers)
83 * LP_ACPI_OWNED[63:32] gpio ownerships for gpios 32-63
84 * LP_ACPI_OWNED[94:64] gpio ownerships for gpios 63-94
85 * ...
86 * LP_INT_ENABLE[31:0] ...
87 * LP_INT_ENABLE[63:31] ...
88 * LP_INT_ENABLE[94:64] ...
89 * LP0_CONFIG1 (gpio 0) config1 reg for gpio 0 (per gpio registers)
90 * LP0_CONFIG2 (gpio 0) config2 reg for gpio 0
91 * LP1_CONFIG1 (gpio 1) config1 reg for gpio 1
92 * LP1_CONFIG2 (gpio 1) config2 reg for gpio 1
93 * LP2_CONFIG1 (gpio 2) ...
94 * LP2_CONFIG2 (gpio 2) ...
95 * ...
96 * LP94_CONFIG1 (gpio 94) ...
97 * LP94_CONFIG2 (gpio 94) ...
98 */
99
lp_gpio_reg(struct gpio_chip * chip,unsigned offset,int reg)100 static unsigned long lp_gpio_reg(struct gpio_chip *chip, unsigned offset,
101 int reg)
102 {
103 struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
104 int reg_offset;
105
106 if (reg == LP_CONFIG1 || reg == LP_CONFIG2)
107 /* per gpio specific config registers */
108 reg_offset = offset * 8;
109 else
110 /* bitmapped registers */
111 reg_offset = (offset / 32) * 4;
112
113 return lg->reg_base + reg + reg_offset;
114 }
115
lp_gpio_request(struct gpio_chip * chip,unsigned offset)116 static int lp_gpio_request(struct gpio_chip *chip, unsigned offset)
117 {
118 struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
119 unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
120 unsigned long conf2 = lp_gpio_reg(chip, offset, LP_CONFIG2);
121 unsigned long acpi_use = lp_gpio_reg(chip, offset, LP_ACPI_OWNED);
122
123 pm_runtime_get(&lg->pdev->dev); /* should we put if failed */
124
125 /* Fail if BIOS reserved pin for ACPI use */
126 if (!(inl(acpi_use) & BIT(offset % 32))) {
127 dev_err(&lg->pdev->dev, "gpio %d reserved for ACPI\n", offset);
128 return -EBUSY;
129 }
130 /* Fail if pin is in alternate function mode (not GPIO mode) */
131 if (!(inl(reg) & USE_SEL_BIT))
132 return -ENODEV;
133
134 /* enable input sensing */
135 outl(inl(conf2) & ~GPINDIS_BIT, conf2);
136
137
138 return 0;
139 }
140
lp_gpio_free(struct gpio_chip * chip,unsigned offset)141 static void lp_gpio_free(struct gpio_chip *chip, unsigned offset)
142 {
143 struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
144 unsigned long conf2 = lp_gpio_reg(chip, offset, LP_CONFIG2);
145
146 /* disable input sensing */
147 outl(inl(conf2) | GPINDIS_BIT, conf2);
148
149 pm_runtime_put(&lg->pdev->dev);
150 }
151
lp_irq_type(struct irq_data * d,unsigned type)152 static int lp_irq_type(struct irq_data *d, unsigned type)
153 {
154 struct lp_gpio *lg = irq_data_get_irq_chip_data(d);
155 u32 hwirq = irqd_to_hwirq(d);
156 unsigned long flags;
157 u32 value;
158 unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_CONFIG1);
159
160 if (hwirq >= lg->chip.ngpio)
161 return -EINVAL;
162
163 spin_lock_irqsave(&lg->lock, flags);
164 value = inl(reg);
165
166 /* set both TRIG_SEL and INV bits to 0 for rising edge */
167 if (type & IRQ_TYPE_EDGE_RISING)
168 value &= ~(TRIG_SEL_BIT | INT_INV_BIT);
169
170 /* TRIG_SEL bit 0, INV bit 1 for falling edge */
171 if (type & IRQ_TYPE_EDGE_FALLING)
172 value = (value | INT_INV_BIT) & ~TRIG_SEL_BIT;
173
174 /* TRIG_SEL bit 1, INV bit 0 for level low */
175 if (type & IRQ_TYPE_LEVEL_LOW)
176 value = (value | TRIG_SEL_BIT) & ~INT_INV_BIT;
177
178 /* TRIG_SEL bit 1, INV bit 1 for level high */
179 if (type & IRQ_TYPE_LEVEL_HIGH)
180 value |= TRIG_SEL_BIT | INT_INV_BIT;
181
182 outl(value, reg);
183 spin_unlock_irqrestore(&lg->lock, flags);
184
185 return 0;
186 }
187
lp_gpio_get(struct gpio_chip * chip,unsigned offset)188 static int lp_gpio_get(struct gpio_chip *chip, unsigned offset)
189 {
190 unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
191 return inl(reg) & IN_LVL_BIT;
192 }
193
lp_gpio_set(struct gpio_chip * chip,unsigned offset,int value)194 static void lp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
195 {
196 struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
197 unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
198 unsigned long flags;
199
200 spin_lock_irqsave(&lg->lock, flags);
201
202 if (value)
203 outl(inl(reg) | OUT_LVL_BIT, reg);
204 else
205 outl(inl(reg) & ~OUT_LVL_BIT, reg);
206
207 spin_unlock_irqrestore(&lg->lock, flags);
208 }
209
lp_gpio_direction_input(struct gpio_chip * chip,unsigned offset)210 static int lp_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
211 {
212 struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
213 unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
214 unsigned long flags;
215
216 spin_lock_irqsave(&lg->lock, flags);
217 outl(inl(reg) | DIR_BIT, reg);
218 spin_unlock_irqrestore(&lg->lock, flags);
219
220 return 0;
221 }
222
lp_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int value)223 static int lp_gpio_direction_output(struct gpio_chip *chip,
224 unsigned offset, int value)
225 {
226 struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
227 unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
228 unsigned long flags;
229
230 lp_gpio_set(chip, offset, value);
231
232 spin_lock_irqsave(&lg->lock, flags);
233 outl(inl(reg) & ~DIR_BIT, reg);
234 spin_unlock_irqrestore(&lg->lock, flags);
235
236 return 0;
237 }
238
lp_gpio_to_irq(struct gpio_chip * chip,unsigned offset)239 static int lp_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
240 {
241 struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
242 return irq_create_mapping(lg->domain, offset);
243 }
244
lp_gpio_irq_handler(unsigned irq,struct irq_desc * desc)245 static void lp_gpio_irq_handler(unsigned irq, struct irq_desc *desc)
246 {
247 struct irq_data *data = irq_desc_get_irq_data(desc);
248 struct lp_gpio *lg = irq_data_get_irq_handler_data(data);
249 struct irq_chip *chip = irq_data_get_irq_chip(data);
250 u32 base, pin, mask;
251 unsigned long reg, pending;
252 unsigned virq;
253
254 /* check from GPIO controller which pin triggered the interrupt */
255 for (base = 0; base < lg->chip.ngpio; base += 32) {
256 reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT);
257
258 while ((pending = inl(reg))) {
259 pin = __ffs(pending);
260 mask = BIT(pin);
261 /* Clear before handling so we don't lose an edge */
262 outl(mask, reg);
263 virq = irq_find_mapping(lg->domain, base + pin);
264 generic_handle_irq(virq);
265 }
266 }
267 chip->irq_eoi(data);
268 }
269
lp_irq_unmask(struct irq_data * d)270 static void lp_irq_unmask(struct irq_data *d)
271 {
272 }
273
lp_irq_mask(struct irq_data * d)274 static void lp_irq_mask(struct irq_data *d)
275 {
276 }
277
lp_irq_enable(struct irq_data * d)278 static void lp_irq_enable(struct irq_data *d)
279 {
280 struct lp_gpio *lg = irq_data_get_irq_chip_data(d);
281 u32 hwirq = irqd_to_hwirq(d);
282 unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE);
283 unsigned long flags;
284
285 spin_lock_irqsave(&lg->lock, flags);
286 outl(inl(reg) | BIT(hwirq % 32), reg);
287 spin_unlock_irqrestore(&lg->lock, flags);
288 }
289
lp_irq_disable(struct irq_data * d)290 static void lp_irq_disable(struct irq_data *d)
291 {
292 struct lp_gpio *lg = irq_data_get_irq_chip_data(d);
293 u32 hwirq = irqd_to_hwirq(d);
294 unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE);
295 unsigned long flags;
296
297 spin_lock_irqsave(&lg->lock, flags);
298 outl(inl(reg) & ~BIT(hwirq % 32), reg);
299 spin_unlock_irqrestore(&lg->lock, flags);
300 }
301
302 static struct irq_chip lp_irqchip = {
303 .name = "LP-GPIO",
304 .irq_mask = lp_irq_mask,
305 .irq_unmask = lp_irq_unmask,
306 .irq_enable = lp_irq_enable,
307 .irq_disable = lp_irq_disable,
308 .irq_set_type = lp_irq_type,
309 .flags = IRQCHIP_SKIP_SET_WAKE,
310 };
311
lp_gpio_irq_init_hw(struct lp_gpio * lg)312 static void lp_gpio_irq_init_hw(struct lp_gpio *lg)
313 {
314 unsigned long reg;
315 unsigned base;
316
317 for (base = 0; base < lg->chip.ngpio; base += 32) {
318 /* disable gpio pin interrupts */
319 reg = lp_gpio_reg(&lg->chip, base, LP_INT_ENABLE);
320 outl(0, reg);
321 /* Clear interrupt status register */
322 reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT);
323 outl(0xffffffff, reg);
324 }
325 }
326
lp_gpio_irq_map(struct irq_domain * d,unsigned int virq,irq_hw_number_t hw)327 static int lp_gpio_irq_map(struct irq_domain *d, unsigned int virq,
328 irq_hw_number_t hw)
329 {
330 struct lp_gpio *lg = d->host_data;
331
332 irq_set_chip_and_handler_name(virq, &lp_irqchip, handle_simple_irq,
333 "demux");
334 irq_set_chip_data(virq, lg);
335 irq_set_irq_type(virq, IRQ_TYPE_NONE);
336
337 return 0;
338 }
339
340 static const struct irq_domain_ops lp_gpio_irq_ops = {
341 .map = lp_gpio_irq_map,
342 };
343
lp_gpio_probe(struct platform_device * pdev)344 static int lp_gpio_probe(struct platform_device *pdev)
345 {
346 struct lp_gpio *lg;
347 struct gpio_chip *gc;
348 struct resource *io_rc, *irq_rc;
349 struct device *dev = &pdev->dev;
350 unsigned long reg_len;
351 unsigned hwirq;
352 int ret = -ENODEV;
353
354 lg = devm_kzalloc(dev, sizeof(struct lp_gpio), GFP_KERNEL);
355 if (!lg) {
356 dev_err(dev, "can't allocate lp_gpio chip data\n");
357 return -ENOMEM;
358 }
359
360 lg->pdev = pdev;
361 platform_set_drvdata(pdev, lg);
362
363 io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0);
364 irq_rc = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
365
366 if (!io_rc) {
367 dev_err(dev, "missing IO resources\n");
368 return -EINVAL;
369 }
370
371 lg->reg_base = io_rc->start;
372 reg_len = resource_size(io_rc);
373
374 if (!devm_request_region(dev, lg->reg_base, reg_len, "lp-gpio")) {
375 dev_err(dev, "failed requesting IO region 0x%x\n",
376 (unsigned int)lg->reg_base);
377 return -EBUSY;
378 }
379
380 spin_lock_init(&lg->lock);
381
382 gc = &lg->chip;
383 gc->label = dev_name(dev);
384 gc->owner = THIS_MODULE;
385 gc->request = lp_gpio_request;
386 gc->free = lp_gpio_free;
387 gc->direction_input = lp_gpio_direction_input;
388 gc->direction_output = lp_gpio_direction_output;
389 gc->get = lp_gpio_get;
390 gc->set = lp_gpio_set;
391 gc->base = -1;
392 gc->ngpio = LP_NUM_GPIO;
393 gc->can_sleep = 0;
394 gc->dev = dev;
395
396 /* set up interrupts */
397 if (irq_rc && irq_rc->start) {
398 hwirq = irq_rc->start;
399 gc->to_irq = lp_gpio_to_irq;
400
401 lg->domain = irq_domain_add_linear(NULL, LP_NUM_GPIO,
402 &lp_gpio_irq_ops, lg);
403 if (!lg->domain)
404 return -ENXIO;
405
406 lp_gpio_irq_init_hw(lg);
407
408 irq_set_handler_data(hwirq, lg);
409 irq_set_chained_handler(hwirq, lp_gpio_irq_handler);
410 }
411
412 ret = gpiochip_add(gc);
413 if (ret) {
414 dev_err(dev, "failed adding lp-gpio chip\n");
415 return ret;
416 }
417 pm_runtime_enable(dev);
418
419 return 0;
420 }
421
lp_gpio_runtime_suspend(struct device * dev)422 static int lp_gpio_runtime_suspend(struct device *dev)
423 {
424 return 0;
425 }
426
lp_gpio_runtime_resume(struct device * dev)427 static int lp_gpio_runtime_resume(struct device *dev)
428 {
429 return 0;
430 }
431
432 static const struct dev_pm_ops lp_gpio_pm_ops = {
433 .runtime_suspend = lp_gpio_runtime_suspend,
434 .runtime_resume = lp_gpio_runtime_resume,
435 };
436
437 static const struct acpi_device_id lynxpoint_gpio_acpi_match[] = {
438 { "INT33C7", 0 },
439 { }
440 };
441 MODULE_DEVICE_TABLE(acpi, lynxpoint_gpio_acpi_match);
442
lp_gpio_remove(struct platform_device * pdev)443 static int lp_gpio_remove(struct platform_device *pdev)
444 {
445 struct lp_gpio *lg = platform_get_drvdata(pdev);
446 int err;
447 err = gpiochip_remove(&lg->chip);
448 if (err)
449 dev_warn(&pdev->dev, "failed to remove gpio_chip.\n");
450 platform_set_drvdata(pdev, NULL);
451 return 0;
452 }
453
454 static struct platform_driver lp_gpio_driver = {
455 .probe = lp_gpio_probe,
456 .remove = lp_gpio_remove,
457 .driver = {
458 .name = "lp_gpio",
459 .owner = THIS_MODULE,
460 .pm = &lp_gpio_pm_ops,
461 .acpi_match_table = ACPI_PTR(lynxpoint_gpio_acpi_match),
462 },
463 };
464
lp_gpio_init(void)465 static int __init lp_gpio_init(void)
466 {
467 return platform_driver_register(&lp_gpio_driver);
468 }
469
470 subsys_initcall(lp_gpio_init);
471