2 * GPIO controller driver for Intel Lynxpoint PCH chipset>
3 * Copyright (c) 2012, Intel Corporation.
5 * Author: Mathias Nyman <mathias.nyman@linux.intel.com>
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.
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
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.
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/gpio.h>
29 #include <linux/slab.h>
30 #include <linux/acpi.h>
31 #include <linux/platform_device.h>
32 #include <linux/pm_runtime.h>
35 /* LynxPoint chipset has support for 94 gpio pins */
37 #define LP_NUM_GPIO 94
39 /* Bitmapped register offsets */
40 #define LP_ACPI_OWNED 0x00 /* Bitmap, set by bios, 0: pin reserved for ACPI */
41 #define LP_GC 0x7C /* set APIC IRQ to IRQ14 or IRQ15 for all pins */
42 #define LP_INT_STAT 0x80
43 #define LP_INT_ENABLE 0x90
45 /* Each pin has two 32 bit config registers, starting at 0x100 */
46 #define LP_CONFIG1 0x100
47 #define LP_CONFIG2 0x104
49 /* LP_CONFIG1 reg bits */
50 #define OUT_LVL_BIT BIT(31)
51 #define IN_LVL_BIT BIT(30)
52 #define TRIG_SEL_BIT BIT(4) /* 0: Edge, 1: Level */
53 #define INT_INV_BIT BIT(3) /* Invert interrupt triggering */
54 #define DIR_BIT BIT(2) /* 0: Output, 1: Input */
55 #define USE_SEL_BIT BIT(0) /* 0: Native, 1: GPIO */
57 /* LP_CONFIG2 reg bits */
58 #define GPINDIS_BIT BIT(2) /* disable input sensing */
59 #define GPIWP_BIT (BIT(0) | BIT(1)) /* weak pull options */
62 struct gpio_chip chip
;
63 struct platform_device
*pdev
;
65 unsigned long reg_base
;
69 * Lynxpoint gpios are controlled through both bitmapped registers and
70 * per gpio specific registers. The bitmapped registers are in chunks of
71 * 3 x 32bit registers to cover all 94 gpios
73 * per gpio specific registers consist of two 32bit registers per gpio
74 * (LP_CONFIG1 and LP_CONFIG2), with 94 gpios there's a total of
75 * 188 config registers.
77 * A simplified view of the register layout look like this:
79 * LP_ACPI_OWNED[31:0] gpio ownerships for gpios 0-31 (bitmapped registers)
80 * LP_ACPI_OWNED[63:32] gpio ownerships for gpios 32-63
81 * LP_ACPI_OWNED[94:64] gpio ownerships for gpios 63-94
83 * LP_INT_ENABLE[31:0] ...
84 * LP_INT_ENABLE[63:31] ...
85 * LP_INT_ENABLE[94:64] ...
86 * LP0_CONFIG1 (gpio 0) config1 reg for gpio 0 (per gpio registers)
87 * LP0_CONFIG2 (gpio 0) config2 reg for gpio 0
88 * LP1_CONFIG1 (gpio 1) config1 reg for gpio 1
89 * LP1_CONFIG2 (gpio 1) config2 reg for gpio 1
90 * LP2_CONFIG1 (gpio 2) ...
91 * LP2_CONFIG2 (gpio 2) ...
93 * LP94_CONFIG1 (gpio 94) ...
94 * LP94_CONFIG2 (gpio 94) ...
97 static unsigned long lp_gpio_reg(struct gpio_chip
*chip
, unsigned offset
,
100 struct lp_gpio
*lg
= container_of(chip
, struct lp_gpio
, chip
);
103 if (reg
== LP_CONFIG1
|| reg
== LP_CONFIG2
)
104 /* per gpio specific config registers */
105 reg_offset
= offset
* 8;
107 /* bitmapped registers */
108 reg_offset
= (offset
/ 32) * 4;
110 return lg
->reg_base
+ reg
+ reg_offset
;
113 static int lp_gpio_request(struct gpio_chip
*chip
, unsigned offset
)
115 struct lp_gpio
*lg
= container_of(chip
, struct lp_gpio
, chip
);
116 unsigned long reg
= lp_gpio_reg(chip
, offset
, LP_CONFIG1
);
117 unsigned long conf2
= lp_gpio_reg(chip
, offset
, LP_CONFIG2
);
118 unsigned long acpi_use
= lp_gpio_reg(chip
, offset
, LP_ACPI_OWNED
);
120 pm_runtime_get(&lg
->pdev
->dev
); /* should we put if failed */
122 /* Fail if BIOS reserved pin for ACPI use */
123 if (!(inl(acpi_use
) & BIT(offset
% 32))) {
124 dev_err(&lg
->pdev
->dev
, "gpio %d reserved for ACPI\n", offset
);
127 /* Fail if pin is in alternate function mode (not GPIO mode) */
128 if (!(inl(reg
) & USE_SEL_BIT
))
131 /* enable input sensing */
132 outl(inl(conf2
) & ~GPINDIS_BIT
, conf2
);
138 static void lp_gpio_free(struct gpio_chip
*chip
, unsigned offset
)
140 struct lp_gpio
*lg
= container_of(chip
, struct lp_gpio
, chip
);
141 unsigned long conf2
= lp_gpio_reg(chip
, offset
, LP_CONFIG2
);
143 /* disable input sensing */
144 outl(inl(conf2
) | GPINDIS_BIT
, conf2
);
146 pm_runtime_put(&lg
->pdev
->dev
);
149 static int lp_irq_type(struct irq_data
*d
, unsigned type
)
151 struct gpio_chip
*gc
= irq_data_get_irq_chip_data(d
);
152 struct lp_gpio
*lg
= container_of(gc
, struct lp_gpio
, chip
);
153 u32 hwirq
= irqd_to_hwirq(d
);
156 unsigned long reg
= lp_gpio_reg(&lg
->chip
, hwirq
, LP_CONFIG1
);
158 if (hwirq
>= lg
->chip
.ngpio
)
161 spin_lock_irqsave(&lg
->lock
, flags
);
164 /* set both TRIG_SEL and INV bits to 0 for rising edge */
165 if (type
& IRQ_TYPE_EDGE_RISING
)
166 value
&= ~(TRIG_SEL_BIT
| INT_INV_BIT
);
168 /* TRIG_SEL bit 0, INV bit 1 for falling edge */
169 if (type
& IRQ_TYPE_EDGE_FALLING
)
170 value
= (value
| INT_INV_BIT
) & ~TRIG_SEL_BIT
;
172 /* TRIG_SEL bit 1, INV bit 0 for level low */
173 if (type
& IRQ_TYPE_LEVEL_LOW
)
174 value
= (value
| TRIG_SEL_BIT
) & ~INT_INV_BIT
;
176 /* TRIG_SEL bit 1, INV bit 1 for level high */
177 if (type
& IRQ_TYPE_LEVEL_HIGH
)
178 value
|= TRIG_SEL_BIT
| INT_INV_BIT
;
181 spin_unlock_irqrestore(&lg
->lock
, flags
);
186 static int lp_gpio_get(struct gpio_chip
*chip
, unsigned offset
)
188 unsigned long reg
= lp_gpio_reg(chip
, offset
, LP_CONFIG1
);
189 return !!(inl(reg
) & IN_LVL_BIT
);
192 static void lp_gpio_set(struct gpio_chip
*chip
, unsigned offset
, int value
)
194 struct lp_gpio
*lg
= container_of(chip
, struct lp_gpio
, chip
);
195 unsigned long reg
= lp_gpio_reg(chip
, offset
, LP_CONFIG1
);
198 spin_lock_irqsave(&lg
->lock
, flags
);
201 outl(inl(reg
) | OUT_LVL_BIT
, reg
);
203 outl(inl(reg
) & ~OUT_LVL_BIT
, reg
);
205 spin_unlock_irqrestore(&lg
->lock
, flags
);
208 static int lp_gpio_direction_input(struct gpio_chip
*chip
, unsigned offset
)
210 struct lp_gpio
*lg
= container_of(chip
, struct lp_gpio
, chip
);
211 unsigned long reg
= lp_gpio_reg(chip
, offset
, LP_CONFIG1
);
214 spin_lock_irqsave(&lg
->lock
, flags
);
215 outl(inl(reg
) | DIR_BIT
, reg
);
216 spin_unlock_irqrestore(&lg
->lock
, flags
);
221 static int lp_gpio_direction_output(struct gpio_chip
*chip
,
222 unsigned offset
, int value
)
224 struct lp_gpio
*lg
= container_of(chip
, struct lp_gpio
, chip
);
225 unsigned long reg
= lp_gpio_reg(chip
, offset
, LP_CONFIG1
);
228 lp_gpio_set(chip
, offset
, value
);
230 spin_lock_irqsave(&lg
->lock
, flags
);
231 outl(inl(reg
) & ~DIR_BIT
, reg
);
232 spin_unlock_irqrestore(&lg
->lock
, flags
);
237 static void lp_gpio_irq_handler(struct irq_desc
*desc
)
239 struct irq_data
*data
= irq_desc_get_irq_data(desc
);
240 struct gpio_chip
*gc
= irq_desc_get_handler_data(desc
);
241 struct lp_gpio
*lg
= container_of(gc
, struct lp_gpio
, chip
);
242 struct irq_chip
*chip
= irq_data_get_irq_chip(data
);
244 unsigned long reg
, ena
, pending
;
246 /* check from GPIO controller which pin triggered the interrupt */
247 for (base
= 0; base
< lg
->chip
.ngpio
; base
+= 32) {
248 reg
= lp_gpio_reg(&lg
->chip
, base
, LP_INT_STAT
);
249 ena
= lp_gpio_reg(&lg
->chip
, base
, LP_INT_ENABLE
);
251 while ((pending
= (inl(reg
) & inl(ena
)))) {
254 pin
= __ffs(pending
);
256 /* Clear before handling so we don't lose an edge */
258 irq
= irq_find_mapping(lg
->chip
.irqdomain
, base
+ pin
);
259 generic_handle_irq(irq
);
265 static void lp_irq_unmask(struct irq_data
*d
)
269 static void lp_irq_mask(struct irq_data
*d
)
273 static void lp_irq_enable(struct irq_data
*d
)
275 struct gpio_chip
*gc
= irq_data_get_irq_chip_data(d
);
276 struct lp_gpio
*lg
= container_of(gc
, struct lp_gpio
, chip
);
277 u32 hwirq
= irqd_to_hwirq(d
);
278 unsigned long reg
= lp_gpio_reg(&lg
->chip
, hwirq
, LP_INT_ENABLE
);
281 spin_lock_irqsave(&lg
->lock
, flags
);
282 outl(inl(reg
) | BIT(hwirq
% 32), reg
);
283 spin_unlock_irqrestore(&lg
->lock
, flags
);
286 static void lp_irq_disable(struct irq_data
*d
)
288 struct gpio_chip
*gc
= irq_data_get_irq_chip_data(d
);
289 struct lp_gpio
*lg
= container_of(gc
, struct lp_gpio
, chip
);
290 u32 hwirq
= irqd_to_hwirq(d
);
291 unsigned long reg
= lp_gpio_reg(&lg
->chip
, hwirq
, LP_INT_ENABLE
);
294 spin_lock_irqsave(&lg
->lock
, flags
);
295 outl(inl(reg
) & ~BIT(hwirq
% 32), reg
);
296 spin_unlock_irqrestore(&lg
->lock
, flags
);
299 static struct irq_chip lp_irqchip
= {
301 .irq_mask
= lp_irq_mask
,
302 .irq_unmask
= lp_irq_unmask
,
303 .irq_enable
= lp_irq_enable
,
304 .irq_disable
= lp_irq_disable
,
305 .irq_set_type
= lp_irq_type
,
306 .flags
= IRQCHIP_SKIP_SET_WAKE
,
309 static void lp_gpio_irq_init_hw(struct lp_gpio
*lg
)
314 for (base
= 0; base
< lg
->chip
.ngpio
; base
+= 32) {
315 /* disable gpio pin interrupts */
316 reg
= lp_gpio_reg(&lg
->chip
, base
, LP_INT_ENABLE
);
318 /* Clear interrupt status register */
319 reg
= lp_gpio_reg(&lg
->chip
, base
, LP_INT_STAT
);
320 outl(0xffffffff, reg
);
324 static int lp_gpio_probe(struct platform_device
*pdev
)
327 struct gpio_chip
*gc
;
328 struct resource
*io_rc
, *irq_rc
;
329 struct device
*dev
= &pdev
->dev
;
330 unsigned long reg_len
;
333 lg
= devm_kzalloc(dev
, sizeof(struct lp_gpio
), GFP_KERNEL
);
338 platform_set_drvdata(pdev
, lg
);
340 io_rc
= platform_get_resource(pdev
, IORESOURCE_IO
, 0);
341 irq_rc
= platform_get_resource(pdev
, IORESOURCE_IRQ
, 0);
344 dev_err(dev
, "missing IO resources\n");
348 lg
->reg_base
= io_rc
->start
;
349 reg_len
= resource_size(io_rc
);
351 if (!devm_request_region(dev
, lg
->reg_base
, reg_len
, "lp-gpio")) {
352 dev_err(dev
, "failed requesting IO region 0x%x\n",
353 (unsigned int)lg
->reg_base
);
357 spin_lock_init(&lg
->lock
);
360 gc
->label
= dev_name(dev
);
361 gc
->owner
= THIS_MODULE
;
362 gc
->request
= lp_gpio_request
;
363 gc
->free
= lp_gpio_free
;
364 gc
->direction_input
= lp_gpio_direction_input
;
365 gc
->direction_output
= lp_gpio_direction_output
;
366 gc
->get
= lp_gpio_get
;
367 gc
->set
= lp_gpio_set
;
369 gc
->ngpio
= LP_NUM_GPIO
;
370 gc
->can_sleep
= false;
373 ret
= gpiochip_add(gc
);
375 dev_err(dev
, "failed adding lp-gpio chip\n");
379 /* set up interrupts */
380 if (irq_rc
&& irq_rc
->start
) {
381 lp_gpio_irq_init_hw(lg
);
382 ret
= gpiochip_irqchip_add(gc
, &lp_irqchip
, 0,
383 handle_simple_irq
, IRQ_TYPE_NONE
);
385 dev_err(dev
, "failed to add irqchip\n");
390 gpiochip_set_chained_irqchip(gc
, &lp_irqchip
,
391 (unsigned)irq_rc
->start
,
392 lp_gpio_irq_handler
);
395 pm_runtime_enable(dev
);
400 static int lp_gpio_runtime_suspend(struct device
*dev
)
405 static int lp_gpio_runtime_resume(struct device
*dev
)
410 static int lp_gpio_resume(struct device
*dev
)
412 struct platform_device
*pdev
= to_platform_device(dev
);
413 struct lp_gpio
*lg
= platform_get_drvdata(pdev
);
417 /* on some hardware suspend clears input sensing, re-enable it here */
418 for (i
= 0; i
< lg
->chip
.ngpio
; i
++) {
419 if (gpiochip_is_requested(&lg
->chip
, i
) != NULL
) {
420 reg
= lp_gpio_reg(&lg
->chip
, i
, LP_CONFIG2
);
421 outl(inl(reg
) & ~GPINDIS_BIT
, reg
);
427 static const struct dev_pm_ops lp_gpio_pm_ops
= {
428 .runtime_suspend
= lp_gpio_runtime_suspend
,
429 .runtime_resume
= lp_gpio_runtime_resume
,
430 .resume
= lp_gpio_resume
,
433 static const struct acpi_device_id lynxpoint_gpio_acpi_match
[] = {
438 MODULE_DEVICE_TABLE(acpi
, lynxpoint_gpio_acpi_match
);
440 static int lp_gpio_remove(struct platform_device
*pdev
)
442 struct lp_gpio
*lg
= platform_get_drvdata(pdev
);
443 pm_runtime_disable(&pdev
->dev
);
444 gpiochip_remove(&lg
->chip
);
448 static struct platform_driver lp_gpio_driver
= {
449 .probe
= lp_gpio_probe
,
450 .remove
= lp_gpio_remove
,
453 .pm
= &lp_gpio_pm_ops
,
454 .acpi_match_table
= ACPI_PTR(lynxpoint_gpio_acpi_match
),
458 static int __init
lp_gpio_init(void)
460 return platform_driver_register(&lp_gpio_driver
);
463 static void __exit
lp_gpio_exit(void)
465 platform_driver_unregister(&lp_gpio_driver
);
468 subsys_initcall(lp_gpio_init
);
469 module_exit(lp_gpio_exit
);
471 MODULE_AUTHOR("Mathias Nyman (Intel)");
472 MODULE_DESCRIPTION("GPIO interface for Intel Lynxpoint");
473 MODULE_LICENSE("GPL");
474 MODULE_ALIAS("platform:lp_gpio");