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1 | // SPDX-License-Identifier: GPL-2.0 | |
2 | /* | |
3 | * GPIO controller driver for Intel Lynxpoint PCH chipset> | |
4 | * Copyright (c) 2012, Intel Corporation. | |
5 | * | |
6 | * Author: Mathias Nyman <mathias.nyman@linux.intel.com> | |
7 | */ | |
8 | ||
9 | #include <linux/acpi.h> | |
10 | #include <linux/bitops.h> | |
11 | #include <linux/gpio/driver.h> | |
12 | #include <linux/interrupt.h> | |
13 | #include <linux/io.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/platform_device.h> | |
17 | #include <linux/pm_runtime.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/types.h> | |
20 | ||
21 | /* LynxPoint chipset has support for 94 gpio pins */ | |
22 | ||
23 | #define LP_NUM_GPIO 94 | |
24 | ||
25 | /* Bitmapped register offsets */ | |
26 | #define LP_ACPI_OWNED 0x00 /* Bitmap, set by bios, 0: pin reserved for ACPI */ | |
27 | #define LP_GC 0x7C /* set APIC IRQ to IRQ14 or IRQ15 for all pins */ | |
28 | #define LP_INT_STAT 0x80 | |
29 | #define LP_INT_ENABLE 0x90 | |
30 | ||
31 | /* Each pin has two 32 bit config registers, starting at 0x100 */ | |
32 | #define LP_CONFIG1 0x100 | |
33 | #define LP_CONFIG2 0x104 | |
34 | ||
35 | /* LP_CONFIG1 reg bits */ | |
36 | #define OUT_LVL_BIT BIT(31) | |
37 | #define IN_LVL_BIT BIT(30) | |
38 | #define TRIG_SEL_BIT BIT(4) /* 0: Edge, 1: Level */ | |
39 | #define INT_INV_BIT BIT(3) /* Invert interrupt triggering */ | |
40 | #define DIR_BIT BIT(2) /* 0: Output, 1: Input */ | |
41 | #define USE_SEL_BIT BIT(0) /* 0: Native, 1: GPIO */ | |
42 | ||
43 | /* LP_CONFIG2 reg bits */ | |
44 | #define GPINDIS_BIT BIT(2) /* disable input sensing */ | |
45 | #define GPIWP_BIT (BIT(0) | BIT(1)) /* weak pull options */ | |
46 | ||
47 | struct lp_gpio { | |
48 | struct gpio_chip chip; | |
49 | struct platform_device *pdev; | |
50 | spinlock_t lock; | |
51 | unsigned long reg_base; | |
52 | }; | |
53 | ||
54 | /* | |
55 | * Lynxpoint gpios are controlled through both bitmapped registers and | |
56 | * per gpio specific registers. The bitmapped registers are in chunks of | |
57 | * 3 x 32bit registers to cover all 94 gpios | |
58 | * | |
59 | * per gpio specific registers consist of two 32bit registers per gpio | |
60 | * (LP_CONFIG1 and LP_CONFIG2), with 94 gpios there's a total of | |
61 | * 188 config registers. | |
62 | * | |
63 | * A simplified view of the register layout look like this: | |
64 | * | |
65 | * LP_ACPI_OWNED[31:0] gpio ownerships for gpios 0-31 (bitmapped registers) | |
66 | * LP_ACPI_OWNED[63:32] gpio ownerships for gpios 32-63 | |
67 | * LP_ACPI_OWNED[94:64] gpio ownerships for gpios 63-94 | |
68 | * ... | |
69 | * LP_INT_ENABLE[31:0] ... | |
70 | * LP_INT_ENABLE[63:31] ... | |
71 | * LP_INT_ENABLE[94:64] ... | |
72 | * LP0_CONFIG1 (gpio 0) config1 reg for gpio 0 (per gpio registers) | |
73 | * LP0_CONFIG2 (gpio 0) config2 reg for gpio 0 | |
74 | * LP1_CONFIG1 (gpio 1) config1 reg for gpio 1 | |
75 | * LP1_CONFIG2 (gpio 1) config2 reg for gpio 1 | |
76 | * LP2_CONFIG1 (gpio 2) ... | |
77 | * LP2_CONFIG2 (gpio 2) ... | |
78 | * ... | |
79 | * LP94_CONFIG1 (gpio 94) ... | |
80 | * LP94_CONFIG2 (gpio 94) ... | |
81 | */ | |
82 | ||
83 | static unsigned long lp_gpio_reg(struct gpio_chip *chip, unsigned offset, | |
84 | int reg) | |
85 | { | |
86 | struct lp_gpio *lg = gpiochip_get_data(chip); | |
87 | int reg_offset; | |
88 | ||
89 | if (reg == LP_CONFIG1 || reg == LP_CONFIG2) | |
90 | /* per gpio specific config registers */ | |
91 | reg_offset = offset * 8; | |
92 | else | |
93 | /* bitmapped registers */ | |
94 | reg_offset = (offset / 32) * 4; | |
95 | ||
96 | return lg->reg_base + reg + reg_offset; | |
97 | } | |
98 | ||
99 | static int lp_gpio_request(struct gpio_chip *chip, unsigned offset) | |
100 | { | |
101 | struct lp_gpio *lg = gpiochip_get_data(chip); | |
102 | unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1); | |
103 | unsigned long conf2 = lp_gpio_reg(chip, offset, LP_CONFIG2); | |
104 | unsigned long acpi_use = lp_gpio_reg(chip, offset, LP_ACPI_OWNED); | |
105 | ||
106 | pm_runtime_get(&lg->pdev->dev); /* should we put if failed */ | |
107 | ||
108 | /* Fail if BIOS reserved pin for ACPI use */ | |
109 | if (!(inl(acpi_use) & BIT(offset % 32))) { | |
110 | dev_err(&lg->pdev->dev, "gpio %d reserved for ACPI\n", offset); | |
111 | return -EBUSY; | |
112 | } | |
113 | /* Fail if pin is in alternate function mode (not GPIO mode) */ | |
114 | if (!(inl(reg) & USE_SEL_BIT)) | |
115 | return -ENODEV; | |
116 | ||
117 | /* enable input sensing */ | |
118 | outl(inl(conf2) & ~GPINDIS_BIT, conf2); | |
119 | ||
120 | ||
121 | return 0; | |
122 | } | |
123 | ||
124 | static void lp_gpio_free(struct gpio_chip *chip, unsigned offset) | |
125 | { | |
126 | struct lp_gpio *lg = gpiochip_get_data(chip); | |
127 | unsigned long conf2 = lp_gpio_reg(chip, offset, LP_CONFIG2); | |
128 | ||
129 | /* disable input sensing */ | |
130 | outl(inl(conf2) | GPINDIS_BIT, conf2); | |
131 | ||
132 | pm_runtime_put(&lg->pdev->dev); | |
133 | } | |
134 | ||
135 | static int lp_irq_type(struct irq_data *d, unsigned type) | |
136 | { | |
137 | struct gpio_chip *gc = irq_data_get_irq_chip_data(d); | |
138 | struct lp_gpio *lg = gpiochip_get_data(gc); | |
139 | u32 hwirq = irqd_to_hwirq(d); | |
140 | unsigned long flags; | |
141 | u32 value; | |
142 | unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_CONFIG1); | |
143 | ||
144 | if (hwirq >= lg->chip.ngpio) | |
145 | return -EINVAL; | |
146 | ||
147 | spin_lock_irqsave(&lg->lock, flags); | |
148 | value = inl(reg); | |
149 | ||
150 | /* set both TRIG_SEL and INV bits to 0 for rising edge */ | |
151 | if (type & IRQ_TYPE_EDGE_RISING) | |
152 | value &= ~(TRIG_SEL_BIT | INT_INV_BIT); | |
153 | ||
154 | /* TRIG_SEL bit 0, INV bit 1 for falling edge */ | |
155 | if (type & IRQ_TYPE_EDGE_FALLING) | |
156 | value = (value | INT_INV_BIT) & ~TRIG_SEL_BIT; | |
157 | ||
158 | /* TRIG_SEL bit 1, INV bit 0 for level low */ | |
159 | if (type & IRQ_TYPE_LEVEL_LOW) | |
160 | value = (value | TRIG_SEL_BIT) & ~INT_INV_BIT; | |
161 | ||
162 | /* TRIG_SEL bit 1, INV bit 1 for level high */ | |
163 | if (type & IRQ_TYPE_LEVEL_HIGH) | |
164 | value |= TRIG_SEL_BIT | INT_INV_BIT; | |
165 | ||
166 | outl(value, reg); | |
167 | spin_unlock_irqrestore(&lg->lock, flags); | |
168 | ||
169 | return 0; | |
170 | } | |
171 | ||
172 | static int lp_gpio_get(struct gpio_chip *chip, unsigned offset) | |
173 | { | |
174 | unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1); | |
175 | return !!(inl(reg) & IN_LVL_BIT); | |
176 | } | |
177 | ||
178 | static void lp_gpio_set(struct gpio_chip *chip, unsigned offset, int value) | |
179 | { | |
180 | struct lp_gpio *lg = gpiochip_get_data(chip); | |
181 | unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1); | |
182 | unsigned long flags; | |
183 | ||
184 | spin_lock_irqsave(&lg->lock, flags); | |
185 | ||
186 | if (value) | |
187 | outl(inl(reg) | OUT_LVL_BIT, reg); | |
188 | else | |
189 | outl(inl(reg) & ~OUT_LVL_BIT, reg); | |
190 | ||
191 | spin_unlock_irqrestore(&lg->lock, flags); | |
192 | } | |
193 | ||
194 | static int lp_gpio_direction_input(struct gpio_chip *chip, unsigned offset) | |
195 | { | |
196 | struct lp_gpio *lg = gpiochip_get_data(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 | outl(inl(reg) | DIR_BIT, reg); | |
202 | spin_unlock_irqrestore(&lg->lock, flags); | |
203 | ||
204 | return 0; | |
205 | } | |
206 | ||
207 | static int lp_gpio_direction_output(struct gpio_chip *chip, | |
208 | unsigned offset, int value) | |
209 | { | |
210 | struct lp_gpio *lg = gpiochip_get_data(chip); | |
211 | unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1); | |
212 | unsigned long flags; | |
213 | ||
214 | lp_gpio_set(chip, offset, value); | |
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 | ||
223 | static void lp_gpio_irq_handler(struct irq_desc *desc) | |
224 | { | |
225 | struct irq_data *data = irq_desc_get_irq_data(desc); | |
226 | struct gpio_chip *gc = irq_desc_get_handler_data(desc); | |
227 | struct lp_gpio *lg = gpiochip_get_data(gc); | |
228 | struct irq_chip *chip = irq_data_get_irq_chip(data); | |
229 | unsigned long reg, ena, pending; | |
230 | u32 base, pin; | |
231 | ||
232 | /* check from GPIO controller which pin triggered the interrupt */ | |
233 | for (base = 0; base < lg->chip.ngpio; base += 32) { | |
234 | reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT); | |
235 | ena = lp_gpio_reg(&lg->chip, base, LP_INT_ENABLE); | |
236 | ||
237 | /* Only interrupts that are enabled */ | |
238 | pending = inl(reg) & inl(ena); | |
239 | ||
240 | for_each_set_bit(pin, &pending, 32) { | |
241 | unsigned irq; | |
242 | ||
243 | /* Clear before handling so we don't lose an edge */ | |
244 | outl(BIT(pin), reg); | |
245 | ||
246 | irq = irq_find_mapping(lg->chip.irq.domain, base + pin); | |
247 | generic_handle_irq(irq); | |
248 | } | |
249 | } | |
250 | chip->irq_eoi(data); | |
251 | } | |
252 | ||
253 | static void lp_irq_unmask(struct irq_data *d) | |
254 | { | |
255 | } | |
256 | ||
257 | static void lp_irq_mask(struct irq_data *d) | |
258 | { | |
259 | } | |
260 | ||
261 | static void lp_irq_enable(struct irq_data *d) | |
262 | { | |
263 | struct gpio_chip *gc = irq_data_get_irq_chip_data(d); | |
264 | struct lp_gpio *lg = gpiochip_get_data(gc); | |
265 | u32 hwirq = irqd_to_hwirq(d); | |
266 | unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE); | |
267 | unsigned long flags; | |
268 | ||
269 | spin_lock_irqsave(&lg->lock, flags); | |
270 | outl(inl(reg) | BIT(hwirq % 32), reg); | |
271 | spin_unlock_irqrestore(&lg->lock, flags); | |
272 | } | |
273 | ||
274 | static void lp_irq_disable(struct irq_data *d) | |
275 | { | |
276 | struct gpio_chip *gc = irq_data_get_irq_chip_data(d); | |
277 | struct lp_gpio *lg = gpiochip_get_data(gc); | |
278 | u32 hwirq = irqd_to_hwirq(d); | |
279 | unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE); | |
280 | unsigned long flags; | |
281 | ||
282 | spin_lock_irqsave(&lg->lock, flags); | |
283 | outl(inl(reg) & ~BIT(hwirq % 32), reg); | |
284 | spin_unlock_irqrestore(&lg->lock, flags); | |
285 | } | |
286 | ||
287 | static struct irq_chip lp_irqchip = { | |
288 | .name = "LP-GPIO", | |
289 | .irq_mask = lp_irq_mask, | |
290 | .irq_unmask = lp_irq_unmask, | |
291 | .irq_enable = lp_irq_enable, | |
292 | .irq_disable = lp_irq_disable, | |
293 | .irq_set_type = lp_irq_type, | |
294 | .flags = IRQCHIP_SKIP_SET_WAKE, | |
295 | }; | |
296 | ||
297 | static void lp_gpio_irq_init_hw(struct lp_gpio *lg) | |
298 | { | |
299 | unsigned long reg; | |
300 | unsigned base; | |
301 | ||
302 | for (base = 0; base < lg->chip.ngpio; base += 32) { | |
303 | /* disable gpio pin interrupts */ | |
304 | reg = lp_gpio_reg(&lg->chip, base, LP_INT_ENABLE); | |
305 | outl(0, reg); | |
306 | /* Clear interrupt status register */ | |
307 | reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT); | |
308 | outl(0xffffffff, reg); | |
309 | } | |
310 | } | |
311 | ||
312 | static int lp_gpio_probe(struct platform_device *pdev) | |
313 | { | |
314 | struct lp_gpio *lg; | |
315 | struct gpio_chip *gc; | |
316 | struct resource *io_rc, *irq_rc; | |
317 | struct device *dev = &pdev->dev; | |
318 | unsigned long reg_len; | |
319 | int ret = -ENODEV; | |
320 | ||
321 | lg = devm_kzalloc(dev, sizeof(struct lp_gpio), GFP_KERNEL); | |
322 | if (!lg) | |
323 | return -ENOMEM; | |
324 | ||
325 | lg->pdev = pdev; | |
326 | platform_set_drvdata(pdev, lg); | |
327 | ||
328 | io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0); | |
329 | irq_rc = platform_get_resource(pdev, IORESOURCE_IRQ, 0); | |
330 | ||
331 | if (!io_rc) { | |
332 | dev_err(dev, "missing IO resources\n"); | |
333 | return -EINVAL; | |
334 | } | |
335 | ||
336 | lg->reg_base = io_rc->start; | |
337 | reg_len = resource_size(io_rc); | |
338 | ||
339 | if (!devm_request_region(dev, lg->reg_base, reg_len, "lp-gpio")) { | |
340 | dev_err(dev, "failed requesting IO region 0x%x\n", | |
341 | (unsigned int)lg->reg_base); | |
342 | return -EBUSY; | |
343 | } | |
344 | ||
345 | spin_lock_init(&lg->lock); | |
346 | ||
347 | gc = &lg->chip; | |
348 | gc->label = dev_name(dev); | |
349 | gc->owner = THIS_MODULE; | |
350 | gc->request = lp_gpio_request; | |
351 | gc->free = lp_gpio_free; | |
352 | gc->direction_input = lp_gpio_direction_input; | |
353 | gc->direction_output = lp_gpio_direction_output; | |
354 | gc->get = lp_gpio_get; | |
355 | gc->set = lp_gpio_set; | |
356 | gc->base = -1; | |
357 | gc->ngpio = LP_NUM_GPIO; | |
358 | gc->can_sleep = false; | |
359 | gc->parent = dev; | |
360 | ||
361 | ret = devm_gpiochip_add_data(dev, gc, lg); | |
362 | if (ret) { | |
363 | dev_err(dev, "failed adding lp-gpio chip\n"); | |
364 | return ret; | |
365 | } | |
366 | ||
367 | /* set up interrupts */ | |
368 | if (irq_rc && irq_rc->start) { | |
369 | lp_gpio_irq_init_hw(lg); | |
370 | ret = gpiochip_irqchip_add(gc, &lp_irqchip, 0, | |
371 | handle_simple_irq, IRQ_TYPE_NONE); | |
372 | if (ret) { | |
373 | dev_err(dev, "failed to add irqchip\n"); | |
374 | return ret; | |
375 | } | |
376 | ||
377 | gpiochip_set_chained_irqchip(gc, &lp_irqchip, | |
378 | (unsigned)irq_rc->start, | |
379 | lp_gpio_irq_handler); | |
380 | } | |
381 | ||
382 | pm_runtime_enable(dev); | |
383 | ||
384 | return 0; | |
385 | } | |
386 | ||
387 | static int lp_gpio_runtime_suspend(struct device *dev) | |
388 | { | |
389 | return 0; | |
390 | } | |
391 | ||
392 | static int lp_gpio_runtime_resume(struct device *dev) | |
393 | { | |
394 | return 0; | |
395 | } | |
396 | ||
397 | static int lp_gpio_resume(struct device *dev) | |
398 | { | |
399 | struct lp_gpio *lg = dev_get_drvdata(dev); | |
400 | unsigned long reg; | |
401 | int i; | |
402 | ||
403 | /* on some hardware suspend clears input sensing, re-enable it here */ | |
404 | for (i = 0; i < lg->chip.ngpio; i++) { | |
405 | if (gpiochip_is_requested(&lg->chip, i) != NULL) { | |
406 | reg = lp_gpio_reg(&lg->chip, i, LP_CONFIG2); | |
407 | outl(inl(reg) & ~GPINDIS_BIT, reg); | |
408 | } | |
409 | } | |
410 | return 0; | |
411 | } | |
412 | ||
413 | static const struct dev_pm_ops lp_gpio_pm_ops = { | |
414 | .runtime_suspend = lp_gpio_runtime_suspend, | |
415 | .runtime_resume = lp_gpio_runtime_resume, | |
416 | .resume = lp_gpio_resume, | |
417 | }; | |
418 | ||
419 | static const struct acpi_device_id lynxpoint_gpio_acpi_match[] = { | |
420 | { "INT33C7", 0 }, | |
421 | { "INT3437", 0 }, | |
422 | { } | |
423 | }; | |
424 | MODULE_DEVICE_TABLE(acpi, lynxpoint_gpio_acpi_match); | |
425 | ||
426 | static int lp_gpio_remove(struct platform_device *pdev) | |
427 | { | |
428 | pm_runtime_disable(&pdev->dev); | |
429 | return 0; | |
430 | } | |
431 | ||
432 | static struct platform_driver lp_gpio_driver = { | |
433 | .probe = lp_gpio_probe, | |
434 | .remove = lp_gpio_remove, | |
435 | .driver = { | |
436 | .name = "lp_gpio", | |
437 | .pm = &lp_gpio_pm_ops, | |
438 | .acpi_match_table = ACPI_PTR(lynxpoint_gpio_acpi_match), | |
439 | }, | |
440 | }; | |
441 | ||
442 | static int __init lp_gpio_init(void) | |
443 | { | |
444 | return platform_driver_register(&lp_gpio_driver); | |
445 | } | |
446 | ||
447 | static void __exit lp_gpio_exit(void) | |
448 | { | |
449 | platform_driver_unregister(&lp_gpio_driver); | |
450 | } | |
451 | ||
452 | subsys_initcall(lp_gpio_init); | |
453 | module_exit(lp_gpio_exit); | |
454 | ||
455 | MODULE_AUTHOR("Mathias Nyman (Intel)"); | |
456 | MODULE_DESCRIPTION("GPIO interface for Intel Lynxpoint"); | |
457 | MODULE_LICENSE("GPL v2"); | |
458 | MODULE_ALIAS("platform:lp_gpio"); |