1 // SPDX-License-Identifier: GPL-2.0
3 * GPIO controller driver for Intel Lynxpoint PCH chipset>
4 * Copyright (c) 2012, Intel Corporation.
6 * Author: Mathias Nyman <mathias.nyman@linux.intel.com>
9 #include <linux/acpi.h>
10 #include <linux/bitops.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/interrupt.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>
21 /* LynxPoint chipset has support for 94 gpio pins */
23 #define LP_NUM_GPIO 94
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
31 /* Each pin has two 32 bit config registers, starting at 0x100 */
32 #define LP_CONFIG1 0x100
33 #define LP_CONFIG2 0x104
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 */
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 */
48 struct gpio_chip chip
;
49 struct platform_device
*pdev
;
51 unsigned long reg_base
;
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
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.
63 * A simplified view of the register layout look like this:
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
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) ...
79 * LP94_CONFIG1 (gpio 94) ...
80 * LP94_CONFIG2 (gpio 94) ...
83 static unsigned long lp_gpio_reg(struct gpio_chip
*chip
, unsigned offset
,
86 struct lp_gpio
*lg
= gpiochip_get_data(chip
);
89 if (reg
== LP_CONFIG1
|| reg
== LP_CONFIG2
)
90 /* per gpio specific config registers */
91 reg_offset
= offset
* 8;
93 /* bitmapped registers */
94 reg_offset
= (offset
/ 32) * 4;
96 return lg
->reg_base
+ reg
+ reg_offset
;
99 static int lp_gpio_request(struct gpio_chip
*chip
, unsigned offset
)
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
);
106 pm_runtime_get(&lg
->pdev
->dev
); /* should we put if failed */
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
);
113 /* Fail if pin is in alternate function mode (not GPIO mode) */
114 if (!(inl(reg
) & USE_SEL_BIT
))
117 /* enable input sensing */
118 outl(inl(conf2
) & ~GPINDIS_BIT
, conf2
);
124 static void lp_gpio_free(struct gpio_chip
*chip
, unsigned offset
)
126 struct lp_gpio
*lg
= gpiochip_get_data(chip
);
127 unsigned long conf2
= lp_gpio_reg(chip
, offset
, LP_CONFIG2
);
129 /* disable input sensing */
130 outl(inl(conf2
) | GPINDIS_BIT
, conf2
);
132 pm_runtime_put(&lg
->pdev
->dev
);
135 static int lp_irq_type(struct irq_data
*d
, unsigned type
)
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
);
142 unsigned long reg
= lp_gpio_reg(&lg
->chip
, hwirq
, LP_CONFIG1
);
144 if (hwirq
>= lg
->chip
.ngpio
)
147 spin_lock_irqsave(&lg
->lock
, flags
);
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
);
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
;
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
;
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
;
167 spin_unlock_irqrestore(&lg
->lock
, flags
);
172 static int lp_gpio_get(struct gpio_chip
*chip
, unsigned offset
)
174 unsigned long reg
= lp_gpio_reg(chip
, offset
, LP_CONFIG1
);
175 return !!(inl(reg
) & IN_LVL_BIT
);
178 static void lp_gpio_set(struct gpio_chip
*chip
, unsigned offset
, int value
)
180 struct lp_gpio
*lg
= gpiochip_get_data(chip
);
181 unsigned long reg
= lp_gpio_reg(chip
, offset
, LP_CONFIG1
);
184 spin_lock_irqsave(&lg
->lock
, flags
);
187 outl(inl(reg
) | OUT_LVL_BIT
, reg
);
189 outl(inl(reg
) & ~OUT_LVL_BIT
, reg
);
191 spin_unlock_irqrestore(&lg
->lock
, flags
);
194 static int lp_gpio_direction_input(struct gpio_chip
*chip
, unsigned offset
)
196 struct lp_gpio
*lg
= gpiochip_get_data(chip
);
197 unsigned long reg
= lp_gpio_reg(chip
, offset
, LP_CONFIG1
);
200 spin_lock_irqsave(&lg
->lock
, flags
);
201 outl(inl(reg
) | DIR_BIT
, reg
);
202 spin_unlock_irqrestore(&lg
->lock
, flags
);
207 static int lp_gpio_direction_output(struct gpio_chip
*chip
,
208 unsigned offset
, int value
)
210 struct lp_gpio
*lg
= gpiochip_get_data(chip
);
211 unsigned long reg
= lp_gpio_reg(chip
, offset
, LP_CONFIG1
);
214 lp_gpio_set(chip
, offset
, value
);
216 spin_lock_irqsave(&lg
->lock
, flags
);
217 outl(inl(reg
) & ~DIR_BIT
, reg
);
218 spin_unlock_irqrestore(&lg
->lock
, flags
);
223 static void lp_gpio_irq_handler(struct irq_desc
*desc
)
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
;
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
);
237 /* Only interrupts that are enabled */
238 pending
= inl(reg
) & inl(ena
);
240 for_each_set_bit(pin
, &pending
, 32) {
243 /* Clear before handling so we don't lose an edge */
246 irq
= irq_find_mapping(lg
->chip
.irq
.domain
, base
+ pin
);
247 generic_handle_irq(irq
);
253 static void lp_irq_unmask(struct irq_data
*d
)
257 static void lp_irq_mask(struct irq_data
*d
)
261 static void lp_irq_enable(struct irq_data
*d
)
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
);
269 spin_lock_irqsave(&lg
->lock
, flags
);
270 outl(inl(reg
) | BIT(hwirq
% 32), reg
);
271 spin_unlock_irqrestore(&lg
->lock
, flags
);
274 static void lp_irq_disable(struct irq_data
*d
)
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
);
282 spin_lock_irqsave(&lg
->lock
, flags
);
283 outl(inl(reg
) & ~BIT(hwirq
% 32), reg
);
284 spin_unlock_irqrestore(&lg
->lock
, flags
);
287 static struct irq_chip lp_irqchip
= {
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
,
297 static void lp_gpio_irq_init_hw(struct lp_gpio
*lg
)
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
);
306 /* Clear interrupt status register */
307 reg
= lp_gpio_reg(&lg
->chip
, base
, LP_INT_STAT
);
308 outl(0xffffffff, reg
);
312 static int lp_gpio_probe(struct platform_device
*pdev
)
315 struct gpio_chip
*gc
;
316 struct resource
*io_rc
, *irq_rc
;
317 struct device
*dev
= &pdev
->dev
;
318 unsigned long reg_len
;
321 lg
= devm_kzalloc(dev
, sizeof(struct lp_gpio
), GFP_KERNEL
);
326 platform_set_drvdata(pdev
, lg
);
328 io_rc
= platform_get_resource(pdev
, IORESOURCE_IO
, 0);
329 irq_rc
= platform_get_resource(pdev
, IORESOURCE_IRQ
, 0);
332 dev_err(dev
, "missing IO resources\n");
336 lg
->reg_base
= io_rc
->start
;
337 reg_len
= resource_size(io_rc
);
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
);
345 spin_lock_init(&lg
->lock
);
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
;
357 gc
->ngpio
= LP_NUM_GPIO
;
358 gc
->can_sleep
= false;
361 ret
= devm_gpiochip_add_data(dev
, gc
, lg
);
363 dev_err(dev
, "failed adding lp-gpio chip\n");
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
);
373 dev_err(dev
, "failed to add irqchip\n");
377 gpiochip_set_chained_irqchip(gc
, &lp_irqchip
,
378 (unsigned)irq_rc
->start
,
379 lp_gpio_irq_handler
);
382 pm_runtime_enable(dev
);
387 static int lp_gpio_runtime_suspend(struct device
*dev
)
392 static int lp_gpio_runtime_resume(struct device
*dev
)
397 static int lp_gpio_resume(struct device
*dev
)
399 struct lp_gpio
*lg
= dev_get_drvdata(dev
);
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
);
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
,
419 static const struct acpi_device_id lynxpoint_gpio_acpi_match
[] = {
424 MODULE_DEVICE_TABLE(acpi
, lynxpoint_gpio_acpi_match
);
426 static int lp_gpio_remove(struct platform_device
*pdev
)
428 pm_runtime_disable(&pdev
->dev
);
432 static struct platform_driver lp_gpio_driver
= {
433 .probe
= lp_gpio_probe
,
434 .remove
= lp_gpio_remove
,
437 .pm
= &lp_gpio_pm_ops
,
438 .acpi_match_table
= ACPI_PTR(lynxpoint_gpio_acpi_match
),
442 static int __init
lp_gpio_init(void)
444 return platform_driver_register(&lp_gpio_driver
);
447 static void __exit
lp_gpio_exit(void)
449 platform_driver_unregister(&lp_gpio_driver
);
452 subsys_initcall(lp_gpio_init
);
453 module_exit(lp_gpio_exit
);
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");