2 * Generic driver for memory-mapped GPIO controllers.
4 * Copyright 2008 MontaVista Software, Inc.
5 * Copyright 2008,2010 Anton Vorontsov <cbouatmailru@gmail.com>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
12 * ....``.```~~~~````.`.`.`.`.```````'',,,.........`````......`.......
14 * ..The simplest form of a GPIO controller that the driver supports is``
15 * `.just a single "data" register, where GPIO state can be read and/or `
16 * `,..written. ,,..``~~~~ .....``.`.`.~~.```.`.........``````.```````
19 _/~~|___/~| . ```~~~~~~ ___/___\___ ,~.`.`.`.`````.~~...,,,,...
20 __________|~$@~~~ %~ /o*o*o*o*o*o\ .. Implementing such a GPIO .
21 o ` ~~~~\___/~~~~ ` controller in FPGA is ,.`
22 `....trivial..'~`.```.```
24 * .```````~~~~`..`.``.``.
25 * . The driver supports `... ,..```.`~~~```````````````....````.``,,
26 * . big-endian notation, just`. .. A bit more sophisticated controllers ,
27 * . register the device with -be`. .with a pair of set/clear-bit registers ,
28 * `.. suffix. ```~~`````....`.` . affecting the data register and the .`
29 * ``.`.``...``` ```.. output pins are also supported.`
30 * ^^ `````.`````````.,``~``~``~~``````
32 * ,..`.`.`...````````````......`.`.`.`.`.`..`.`.`..
33 * .. The expectation is that in at least some cases . ,-~~~-,
34 * .this will be used with roll-your-own ASIC/FPGA .` \ /
35 * .logic in Verilog or VHDL. ~~~`````````..`````~~` \ /
36 * ..````````......``````````` \o_
40 * ...`````~~`.....``.`..........``````.`.``.```........``.
41 * ` 8, 16, 32 and 64 bits registers are supported, and``.
42 * . the number of GPIOs is determined by the width of ~
43 * .. the registers. ,............```.`.`..`.`.~~~.`.`.`~
47 #include <linux/init.h>
48 #include <linux/err.h>
49 #include <linux/bug.h>
50 #include <linux/kernel.h>
51 #include <linux/module.h>
52 #include <linux/spinlock.h>
53 #include <linux/compiler.h>
54 #include <linux/types.h>
55 #include <linux/errno.h>
56 #include <linux/log2.h>
57 #include <linux/ioport.h>
59 #include <linux/gpio/driver.h>
60 #include <linux/slab.h>
61 #include <linux/bitops.h>
62 #include <linux/platform_device.h>
63 #include <linux/mod_devicetable.h>
65 #include <linux/of_device.h>
67 static void bgpio_write8(void __iomem
*reg
, unsigned long data
)
72 static unsigned long bgpio_read8(void __iomem
*reg
)
77 static void bgpio_write16(void __iomem
*reg
, unsigned long data
)
82 static unsigned long bgpio_read16(void __iomem
*reg
)
87 static void bgpio_write32(void __iomem
*reg
, unsigned long data
)
92 static unsigned long bgpio_read32(void __iomem
*reg
)
97 #if BITS_PER_LONG >= 64
98 static void bgpio_write64(void __iomem
*reg
, unsigned long data
)
103 static unsigned long bgpio_read64(void __iomem
*reg
)
107 #endif /* BITS_PER_LONG >= 64 */
109 static void bgpio_write16be(void __iomem
*reg
, unsigned long data
)
111 iowrite16be(data
, reg
);
114 static unsigned long bgpio_read16be(void __iomem
*reg
)
116 return ioread16be(reg
);
119 static void bgpio_write32be(void __iomem
*reg
, unsigned long data
)
121 iowrite32be(data
, reg
);
124 static unsigned long bgpio_read32be(void __iomem
*reg
)
126 return ioread32be(reg
);
129 static unsigned long bgpio_pin2mask(struct gpio_chip
*gc
, unsigned int pin
)
134 static unsigned long bgpio_pin2mask_be(struct gpio_chip
*gc
,
137 return BIT(gc
->bgpio_bits
- 1 - pin
);
140 static int bgpio_get_set(struct gpio_chip
*gc
, unsigned int gpio
)
142 unsigned long pinmask
= gc
->pin2mask(gc
, gpio
);
144 if (gc
->bgpio_dir
& pinmask
)
145 return !!(gc
->read_reg(gc
->reg_set
) & pinmask
);
147 return !!(gc
->read_reg(gc
->reg_dat
) & pinmask
);
150 static int bgpio_get(struct gpio_chip
*gc
, unsigned int gpio
)
152 return !!(gc
->read_reg(gc
->reg_dat
) & gc
->pin2mask(gc
, gpio
));
155 static void bgpio_set_none(struct gpio_chip
*gc
, unsigned int gpio
, int val
)
159 static void bgpio_set(struct gpio_chip
*gc
, unsigned int gpio
, int val
)
161 unsigned long mask
= gc
->pin2mask(gc
, gpio
);
164 spin_lock_irqsave(&gc
->bgpio_lock
, flags
);
167 gc
->bgpio_data
|= mask
;
169 gc
->bgpio_data
&= ~mask
;
171 gc
->write_reg(gc
->reg_dat
, gc
->bgpio_data
);
173 spin_unlock_irqrestore(&gc
->bgpio_lock
, flags
);
176 static void bgpio_set_with_clear(struct gpio_chip
*gc
, unsigned int gpio
,
179 unsigned long mask
= gc
->pin2mask(gc
, gpio
);
182 gc
->write_reg(gc
->reg_set
, mask
);
184 gc
->write_reg(gc
->reg_clr
, mask
);
187 static void bgpio_set_set(struct gpio_chip
*gc
, unsigned int gpio
, int val
)
189 unsigned long mask
= gc
->pin2mask(gc
, gpio
);
192 spin_lock_irqsave(&gc
->bgpio_lock
, flags
);
195 gc
->bgpio_data
|= mask
;
197 gc
->bgpio_data
&= ~mask
;
199 gc
->write_reg(gc
->reg_set
, gc
->bgpio_data
);
201 spin_unlock_irqrestore(&gc
->bgpio_lock
, flags
);
204 static void bgpio_multiple_get_masks(struct gpio_chip
*gc
,
205 unsigned long *mask
, unsigned long *bits
,
206 unsigned long *set_mask
,
207 unsigned long *clear_mask
)
214 for (i
= 0; i
< gc
->bgpio_bits
; i
++) {
217 if (__test_and_clear_bit(i
, mask
)) {
218 if (test_bit(i
, bits
))
219 *set_mask
|= gc
->pin2mask(gc
, i
);
221 *clear_mask
|= gc
->pin2mask(gc
, i
);
226 static void bgpio_set_multiple_single_reg(struct gpio_chip
*gc
,
232 unsigned long set_mask
, clear_mask
;
234 spin_lock_irqsave(&gc
->bgpio_lock
, flags
);
236 bgpio_multiple_get_masks(gc
, mask
, bits
, &set_mask
, &clear_mask
);
238 gc
->bgpio_data
|= set_mask
;
239 gc
->bgpio_data
&= ~clear_mask
;
241 gc
->write_reg(reg
, gc
->bgpio_data
);
243 spin_unlock_irqrestore(&gc
->bgpio_lock
, flags
);
246 static void bgpio_set_multiple(struct gpio_chip
*gc
, unsigned long *mask
,
249 bgpio_set_multiple_single_reg(gc
, mask
, bits
, gc
->reg_dat
);
252 static void bgpio_set_multiple_set(struct gpio_chip
*gc
, unsigned long *mask
,
255 bgpio_set_multiple_single_reg(gc
, mask
, bits
, gc
->reg_set
);
258 static void bgpio_set_multiple_with_clear(struct gpio_chip
*gc
,
262 unsigned long set_mask
, clear_mask
;
264 bgpio_multiple_get_masks(gc
, mask
, bits
, &set_mask
, &clear_mask
);
267 gc
->write_reg(gc
->reg_set
, set_mask
);
269 gc
->write_reg(gc
->reg_clr
, clear_mask
);
272 static int bgpio_simple_dir_in(struct gpio_chip
*gc
, unsigned int gpio
)
277 static int bgpio_dir_out_err(struct gpio_chip
*gc
, unsigned int gpio
,
283 static int bgpio_simple_dir_out(struct gpio_chip
*gc
, unsigned int gpio
,
286 gc
->set(gc
, gpio
, val
);
291 static int bgpio_dir_in(struct gpio_chip
*gc
, unsigned int gpio
)
295 spin_lock_irqsave(&gc
->bgpio_lock
, flags
);
297 gc
->bgpio_dir
&= ~gc
->pin2mask(gc
, gpio
);
298 gc
->write_reg(gc
->reg_dir
, gc
->bgpio_dir
);
300 spin_unlock_irqrestore(&gc
->bgpio_lock
, flags
);
305 static int bgpio_get_dir(struct gpio_chip
*gc
, unsigned int gpio
)
307 /* Return 0 if output, 1 of input */
308 return !(gc
->read_reg(gc
->reg_dir
) & gc
->pin2mask(gc
, gpio
));
311 static int bgpio_dir_out(struct gpio_chip
*gc
, unsigned int gpio
, int val
)
315 gc
->set(gc
, gpio
, val
);
317 spin_lock_irqsave(&gc
->bgpio_lock
, flags
);
319 gc
->bgpio_dir
|= gc
->pin2mask(gc
, gpio
);
320 gc
->write_reg(gc
->reg_dir
, gc
->bgpio_dir
);
322 spin_unlock_irqrestore(&gc
->bgpio_lock
, flags
);
327 static int bgpio_dir_in_inv(struct gpio_chip
*gc
, unsigned int gpio
)
331 spin_lock_irqsave(&gc
->bgpio_lock
, flags
);
333 gc
->bgpio_dir
|= gc
->pin2mask(gc
, gpio
);
334 gc
->write_reg(gc
->reg_dir
, gc
->bgpio_dir
);
336 spin_unlock_irqrestore(&gc
->bgpio_lock
, flags
);
341 static int bgpio_dir_out_inv(struct gpio_chip
*gc
, unsigned int gpio
, int val
)
345 gc
->set(gc
, gpio
, val
);
347 spin_lock_irqsave(&gc
->bgpio_lock
, flags
);
349 gc
->bgpio_dir
&= ~gc
->pin2mask(gc
, gpio
);
350 gc
->write_reg(gc
->reg_dir
, gc
->bgpio_dir
);
352 spin_unlock_irqrestore(&gc
->bgpio_lock
, flags
);
357 static int bgpio_get_dir_inv(struct gpio_chip
*gc
, unsigned int gpio
)
359 /* Return 0 if output, 1 if input */
360 return !!(gc
->read_reg(gc
->reg_dir
) & gc
->pin2mask(gc
, gpio
));
363 static int bgpio_setup_accessors(struct device
*dev
,
364 struct gpio_chip
*gc
,
369 switch (gc
->bgpio_bits
) {
371 gc
->read_reg
= bgpio_read8
;
372 gc
->write_reg
= bgpio_write8
;
376 gc
->read_reg
= bgpio_read16be
;
377 gc
->write_reg
= bgpio_write16be
;
379 gc
->read_reg
= bgpio_read16
;
380 gc
->write_reg
= bgpio_write16
;
385 gc
->read_reg
= bgpio_read32be
;
386 gc
->write_reg
= bgpio_write32be
;
388 gc
->read_reg
= bgpio_read32
;
389 gc
->write_reg
= bgpio_write32
;
392 #if BITS_PER_LONG >= 64
396 "64 bit big endian byte order unsupported\n");
399 gc
->read_reg
= bgpio_read64
;
400 gc
->write_reg
= bgpio_write64
;
403 #endif /* BITS_PER_LONG >= 64 */
405 dev_err(dev
, "unsupported data width %u bits\n", gc
->bgpio_bits
);
409 gc
->pin2mask
= bit_be
? bgpio_pin2mask_be
: bgpio_pin2mask
;
415 * Create the device and allocate the resources. For setting GPIO's there are
416 * three supported configurations:
418 * - single input/output register resource (named "dat").
419 * - set/clear pair (named "set" and "clr").
420 * - single output register resource and single input resource ("set" and
423 * For the single output register, this drives a 1 by setting a bit and a zero
424 * by clearing a bit. For the set clr pair, this drives a 1 by setting a bit
425 * in the set register and clears it by setting a bit in the clear register.
426 * The configuration is detected by which resources are present.
428 * For setting the GPIO direction, there are three supported configurations:
430 * - simple bidirection GPIO that requires no configuration.
431 * - an output direction register (named "dirout") where a 1 bit
432 * indicates the GPIO is an output.
433 * - an input direction register (named "dirin") where a 1 bit indicates
434 * the GPIO is an input.
436 static int bgpio_setup_io(struct gpio_chip
*gc
,
450 gc
->set
= bgpio_set_with_clear
;
451 gc
->set_multiple
= bgpio_set_multiple_with_clear
;
452 } else if (set
&& !clr
) {
454 gc
->set
= bgpio_set_set
;
455 gc
->set_multiple
= bgpio_set_multiple_set
;
456 } else if (flags
& BGPIOF_NO_OUTPUT
) {
457 gc
->set
= bgpio_set_none
;
458 gc
->set_multiple
= NULL
;
461 gc
->set_multiple
= bgpio_set_multiple
;
464 if (!(flags
& BGPIOF_UNREADABLE_REG_SET
) &&
465 (flags
& BGPIOF_READ_OUTPUT_REG_SET
))
466 gc
->get
= bgpio_get_set
;
473 static int bgpio_setup_direction(struct gpio_chip
*gc
,
474 void __iomem
*dirout
,
478 if (dirout
&& dirin
) {
481 gc
->reg_dir
= dirout
;
482 gc
->direction_output
= bgpio_dir_out
;
483 gc
->direction_input
= bgpio_dir_in
;
484 gc
->get_direction
= bgpio_get_dir
;
487 gc
->direction_output
= bgpio_dir_out_inv
;
488 gc
->direction_input
= bgpio_dir_in_inv
;
489 gc
->get_direction
= bgpio_get_dir_inv
;
491 if (flags
& BGPIOF_NO_OUTPUT
)
492 gc
->direction_output
= bgpio_dir_out_err
;
494 gc
->direction_output
= bgpio_simple_dir_out
;
495 gc
->direction_input
= bgpio_simple_dir_in
;
501 static int bgpio_request(struct gpio_chip
*chip
, unsigned gpio_pin
)
503 if (gpio_pin
< chip
->ngpio
)
509 int bgpio_init(struct gpio_chip
*gc
, struct device
*dev
,
510 unsigned long sz
, void __iomem
*dat
, void __iomem
*set
,
511 void __iomem
*clr
, void __iomem
*dirout
, void __iomem
*dirin
,
516 if (!is_power_of_2(sz
))
519 gc
->bgpio_bits
= sz
* 8;
520 if (gc
->bgpio_bits
> BITS_PER_LONG
)
523 spin_lock_init(&gc
->bgpio_lock
);
525 gc
->label
= dev_name(dev
);
527 gc
->ngpio
= gc
->bgpio_bits
;
528 gc
->request
= bgpio_request
;
530 ret
= bgpio_setup_io(gc
, dat
, set
, clr
, flags
);
534 ret
= bgpio_setup_accessors(dev
, gc
, flags
& BGPIOF_BIG_ENDIAN
,
535 flags
& BGPIOF_BIG_ENDIAN_BYTE_ORDER
);
539 ret
= bgpio_setup_direction(gc
, dirout
, dirin
, flags
);
543 gc
->bgpio_data
= gc
->read_reg(gc
->reg_dat
);
544 if (gc
->set
== bgpio_set_set
&&
545 !(flags
& BGPIOF_UNREADABLE_REG_SET
))
546 gc
->bgpio_data
= gc
->read_reg(gc
->reg_set
);
547 if (gc
->reg_dir
&& !(flags
& BGPIOF_UNREADABLE_REG_DIR
))
548 gc
->bgpio_dir
= gc
->read_reg(gc
->reg_dir
);
552 EXPORT_SYMBOL_GPL(bgpio_init
);
554 #if IS_ENABLED(CONFIG_GPIO_GENERIC_PLATFORM)
556 static void __iomem
*bgpio_map(struct platform_device
*pdev
,
558 resource_size_t sane_sz
)
563 r
= platform_get_resource_byname(pdev
, IORESOURCE_MEM
, name
);
567 sz
= resource_size(r
);
569 return IOMEM_ERR_PTR(-EINVAL
);
571 return devm_ioremap_resource(&pdev
->dev
, r
);
575 static const struct of_device_id bgpio_of_match
[] = {
576 { .compatible
= "brcm,bcm6345-gpio" },
577 { .compatible
= "wd,mbl-gpio" },
578 { .compatible
= "ni,169445-nand-gpio" },
581 MODULE_DEVICE_TABLE(of
, bgpio_of_match
);
583 static struct bgpio_pdata
*bgpio_parse_dt(struct platform_device
*pdev
,
584 unsigned long *flags
)
586 struct bgpio_pdata
*pdata
;
588 if (!of_match_device(bgpio_of_match
, &pdev
->dev
))
591 pdata
= devm_kzalloc(&pdev
->dev
, sizeof(struct bgpio_pdata
),
594 return ERR_PTR(-ENOMEM
);
598 if (of_device_is_big_endian(pdev
->dev
.of_node
))
599 *flags
|= BGPIOF_BIG_ENDIAN_BYTE_ORDER
;
601 if (of_property_read_bool(pdev
->dev
.of_node
, "no-output"))
602 *flags
|= BGPIOF_NO_OUTPUT
;
607 static struct bgpio_pdata
*bgpio_parse_dt(struct platform_device
*pdev
,
608 unsigned long *flags
)
612 #endif /* CONFIG_OF */
614 static int bgpio_pdev_probe(struct platform_device
*pdev
)
616 struct device
*dev
= &pdev
->dev
;
621 void __iomem
*dirout
;
624 unsigned long flags
= 0;
626 struct gpio_chip
*gc
;
627 struct bgpio_pdata
*pdata
;
629 pdata
= bgpio_parse_dt(pdev
, &flags
);
631 return PTR_ERR(pdata
);
634 pdata
= dev_get_platdata(dev
);
635 flags
= pdev
->id_entry
->driver_data
;
638 r
= platform_get_resource_byname(pdev
, IORESOURCE_MEM
, "dat");
642 sz
= resource_size(r
);
644 dat
= bgpio_map(pdev
, "dat", sz
);
648 set
= bgpio_map(pdev
, "set", sz
);
652 clr
= bgpio_map(pdev
, "clr", sz
);
656 dirout
= bgpio_map(pdev
, "dirout", sz
);
658 return PTR_ERR(dirout
);
660 dirin
= bgpio_map(pdev
, "dirin", sz
);
662 return PTR_ERR(dirin
);
664 gc
= devm_kzalloc(&pdev
->dev
, sizeof(*gc
), GFP_KERNEL
);
668 err
= bgpio_init(gc
, dev
, sz
, dat
, set
, clr
, dirout
, dirin
, flags
);
674 gc
->label
= pdata
->label
;
675 gc
->base
= pdata
->base
;
676 if (pdata
->ngpio
> 0)
677 gc
->ngpio
= pdata
->ngpio
;
680 platform_set_drvdata(pdev
, gc
);
682 return devm_gpiochip_add_data(&pdev
->dev
, gc
, NULL
);
685 static const struct platform_device_id bgpio_id_table
[] = {
687 .name
= "basic-mmio-gpio",
690 .name
= "basic-mmio-gpio-be",
691 .driver_data
= BGPIOF_BIG_ENDIAN
,
695 MODULE_DEVICE_TABLE(platform
, bgpio_id_table
);
697 static struct platform_driver bgpio_driver
= {
699 .name
= "basic-mmio-gpio",
700 .of_match_table
= of_match_ptr(bgpio_of_match
),
702 .id_table
= bgpio_id_table
,
703 .probe
= bgpio_pdev_probe
,
706 module_platform_driver(bgpio_driver
);
708 #endif /* CONFIG_GPIO_GENERIC_PLATFORM */
710 MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers");
711 MODULE_AUTHOR("Anton Vorontsov <cbouatmailru@gmail.com>");
712 MODULE_LICENSE("GPL");