1 // SPDX-License-Identifier: GPL-2.0+
3  * Generic driver for memory-mapped GPIO controllers.
10  * ..The simplest form of a GPIO controller that the driver supports is``
11  *  `.just a single "data" register, where GPIO state can be read and/or `
16 __________|~$@~~~        %~    /o*o*o*o*o*o\   .. Implementing such a GPIO .
22  * .   big-endian notation, just`.  .. A bit more sophisticated controllers ,
23  *  . register the device with -be`. .with a pair of set/clear-bit registers ,
29  * .. The expectation is that in at least some cases .    ,-~~~-,
30  *  .this will be used with roll-your-own ASIC/FPGA .`     \   /
59 #include <linux/gpio/driver.h>
127 	if (gc->be_bits)  in bgpio_line2mask()
128 		return BIT(gc->bgpio_bits - 1 - line);  in bgpio_line2mask()
132 static int bgpio_get_set(struct gpio_chip *gc, unsigned int gpio)  in bgpio_get_set()  argument
134 	unsigned long pinmask = bgpio_line2mask(gc, gpio);  in bgpio_get_set()
135 	bool dir = !!(gc->bgpio_dir & pinmask);  in bgpio_get_set()
138 		return !!(gc->read_reg(gc->reg_set) & pinmask);  in bgpio_get_set()
140 		return !!(gc->read_reg(gc->reg_dat) & pinmask);  in bgpio_get_set()
144  * This assumes that the bits in the GPIO register are in native endianness.
156 	set_mask = *mask & gc->bgpio_dir;  in bgpio_get_set_multiple()
157 	get_mask = *mask & ~gc->bgpio_dir;  in bgpio_get_set_multiple()
160 		*bits |= gc->read_reg(gc->reg_set) & set_mask;  in bgpio_get_set_multiple()
162 		*bits |= gc->read_reg(gc->reg_dat) & get_mask;  in bgpio_get_set_multiple()
167 static int bgpio_get(struct gpio_chip *gc, unsigned int gpio)  in bgpio_get()  argument
169 	return !!(gc->read_reg(gc->reg_dat) & bgpio_line2mask(gc, gpio));  in bgpio_get()
173  * This only works if the bits in the GPIO register are in native endianness.
180 	*bits |= gc->read_reg(gc->reg_dat) & *mask;  in bgpio_get_multiple()
198 	for_each_set_bit(bit, mask, gc->ngpio)  in bgpio_get_multiple_be()
202 	val = gc->read_reg(gc->reg_dat) & readmask;  in bgpio_get_multiple_be()
208 	for_each_set_bit(bit, &val, gc->ngpio)  in bgpio_get_multiple_be()
214 static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)  in bgpio_set_none()  argument
218 static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)  in bgpio_set()  argument
220 	unsigned long mask = bgpio_line2mask(gc, gpio);  in bgpio_set()
223 	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);  in bgpio_set()
226 		gc->bgpio_data |= mask;  in bgpio_set()
228 		gc->bgpio_data &= ~mask;  in bgpio_set()
230 	gc->write_reg(gc->reg_dat, gc->bgpio_data);  in bgpio_set()
232 	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);  in bgpio_set()
235 static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,  in bgpio_set_with_clear()  argument
238 	unsigned long mask = bgpio_line2mask(gc, gpio);  in bgpio_set_with_clear()
241 		gc->write_reg(gc->reg_set, mask);  in bgpio_set_with_clear()
243 		gc->write_reg(gc->reg_clr, mask);  in bgpio_set_with_clear()
246 static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)  in bgpio_set_set()  argument
248 	unsigned long mask = bgpio_line2mask(gc, gpio);  in bgpio_set_set()
251 	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);  in bgpio_set_set()
254 		gc->bgpio_data |= mask;  in bgpio_set_set()
256 		gc->bgpio_data &= ~mask;  in bgpio_set_set()
258 	gc->write_reg(gc->reg_set, gc->bgpio_data);  in bgpio_set_set()
260 	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);  in bgpio_set_set()
273 	for_each_set_bit(i, mask, gc->bgpio_bits) {  in bgpio_multiple_get_masks()
289 	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);  in bgpio_set_multiple_single_reg()
293 	gc->bgpio_data |= set_mask;  in bgpio_set_multiple_single_reg()
294 	gc->bgpio_data &= ~clear_mask;  in bgpio_set_multiple_single_reg()
296 	gc->write_reg(reg, gc->bgpio_data);  in bgpio_set_multiple_single_reg()
298 	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);  in bgpio_set_multiple_single_reg()
304 	bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_dat);  in bgpio_set_multiple()
310 	bgpio_set_multiple_single_reg(gc, mask, bits, gc->reg_set);  in bgpio_set_multiple_set()
322 		gc->write_reg(gc->reg_set, set_mask);  in bgpio_set_multiple_with_clear()
324 		gc->write_reg(gc->reg_clr, clear_mask);  in bgpio_set_multiple_with_clear()
327 static int bgpio_dir_return(struct gpio_chip *gc, unsigned int gpio, bool dir_out)  in bgpio_dir_return()  argument
329 	if (!gc->bgpio_pinctrl)  in bgpio_dir_return()
333 		return pinctrl_gpio_direction_output(gc, gpio);  in bgpio_dir_return()
335 		return pinctrl_gpio_direction_input(gc, gpio);  in bgpio_dir_return()
338 static int bgpio_simple_dir_in(struct gpio_chip *gc, unsigned int gpio)  in bgpio_simple_dir_in()  argument
340 	return bgpio_dir_return(gc, gpio, false);  in bgpio_simple_dir_in()
343 static int bgpio_dir_out_err(struct gpio_chip *gc, unsigned int gpio,  in bgpio_dir_out_err()  argument
346 	return -EINVAL;  in bgpio_dir_out_err()
349 static int bgpio_simple_dir_out(struct gpio_chip *gc, unsigned int gpio,  in bgpio_simple_dir_out()  argument
352 	gc->set(gc, gpio, val);  in bgpio_simple_dir_out()
354 	return bgpio_dir_return(gc, gpio, true);  in bgpio_simple_dir_out()
357 static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)  in bgpio_dir_in()  argument
361 	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);  in bgpio_dir_in()
363 	gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);  in bgpio_dir_in()
365 	if (gc->reg_dir_in)  in bgpio_dir_in()
366 		gc->write_reg(gc->reg_dir_in, ~gc->bgpio_dir);  in bgpio_dir_in()
367 	if (gc->reg_dir_out)  in bgpio_dir_in()
368 		gc->write_reg(gc->reg_dir_out, gc->bgpio_dir);  in bgpio_dir_in()
370 	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);  in bgpio_dir_in()
372 	return bgpio_dir_return(gc, gpio, false);  in bgpio_dir_in()
375 static int bgpio_get_dir(struct gpio_chip *gc, unsigned int gpio)  in bgpio_get_dir()  argument
378 	if (gc->bgpio_dir_unreadable) {  in bgpio_get_dir()
379 		if (gc->bgpio_dir & bgpio_line2mask(gc, gpio))  in bgpio_get_dir()
384 	if (gc->reg_dir_out) {  in bgpio_get_dir()
385 		if (gc->read_reg(gc->reg_dir_out) & bgpio_line2mask(gc, gpio))  in bgpio_get_dir()
390 	if (gc->reg_dir_in)  in bgpio_get_dir()
391 		if (!(gc->read_reg(gc->reg_dir_in) & bgpio_line2mask(gc, gpio)))  in bgpio_get_dir()
397 static void bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)  in bgpio_dir_out()  argument
401 	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);  in bgpio_dir_out()
403 	gc->bgpio_dir |= bgpio_line2mask(gc, gpio);  in bgpio_dir_out()
405 	if (gc->reg_dir_in)  in bgpio_dir_out()
406 		gc->write_reg(gc->reg_dir_in, ~gc->bgpio_dir);  in bgpio_dir_out()
407 	if (gc->reg_dir_out)  in bgpio_dir_out()
408 		gc->write_reg(gc->reg_dir_out, gc->bgpio_dir);  in bgpio_dir_out()
410 	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);  in bgpio_dir_out()
413 static int bgpio_dir_out_dir_first(struct gpio_chip *gc, unsigned int gpio,  in bgpio_dir_out_dir_first()  argument
416 	bgpio_dir_out(gc, gpio, val);  in bgpio_dir_out_dir_first()
417 	gc->set(gc, gpio, val);  in bgpio_dir_out_dir_first()
418 	return bgpio_dir_return(gc, gpio, true);  in bgpio_dir_out_dir_first()
421 static int bgpio_dir_out_val_first(struct gpio_chip *gc, unsigned int gpio,  in bgpio_dir_out_val_first()  argument
424 	gc->set(gc, gpio, val);  in bgpio_dir_out_val_first()
425 	bgpio_dir_out(gc, gpio, val);  in bgpio_dir_out_val_first()
426 	return bgpio_dir_return(gc, gpio, true);  in bgpio_dir_out_val_first()
434 	switch (gc->bgpio_bits) {  in bgpio_setup_accessors()
436 		gc->read_reg	= bgpio_read8;  in bgpio_setup_accessors()
437 		gc->write_reg	= bgpio_write8;  in bgpio_setup_accessors()
441 			gc->read_reg	= bgpio_read16be;  in bgpio_setup_accessors()
442 			gc->write_reg	= bgpio_write16be;  in bgpio_setup_accessors()
444 			gc->read_reg	= bgpio_read16;  in bgpio_setup_accessors()
445 			gc->write_reg	= bgpio_write16;  in bgpio_setup_accessors()
450 			gc->read_reg	= bgpio_read32be;  in bgpio_setup_accessors()
451 			gc->write_reg	= bgpio_write32be;  in bgpio_setup_accessors()
453 			gc->read_reg	= bgpio_read32;  in bgpio_setup_accessors()
454 			gc->write_reg	= bgpio_write32;  in bgpio_setup_accessors()
462 			return -EINVAL;  in bgpio_setup_accessors()
464 			gc->read_reg	= bgpio_read64;  in bgpio_setup_accessors()
465 			gc->write_reg	= bgpio_write64;  in bgpio_setup_accessors()
470 		dev_err(dev, "unsupported data width %u bits\n", gc->bgpio_bits);  in bgpio_setup_accessors()
471 		return -EINVAL;  in bgpio_setup_accessors()
478  * Create the device and allocate the resources.  For setting GPIO's there are
481  *	- single input/output register resource (named "dat").
482  *	- set/clear pair (named "set" and "clr").
483  *	- single output register resource and single input resource ("set" and
491  * For setting the GPIO direction, there are three supported configurations:
493  *	- simple bidirection GPIO that requires no configuration.
494  *	- an output direction register (named "dirout") where a 1 bit
495  *	indicates the GPIO is an output.
496  *	- an input direction register (named "dirin") where a 1 bit indicates
497  *	the GPIO is an input.
506 	gc->reg_dat = dat;  in bgpio_setup_io()
507 	if (!gc->reg_dat)  in bgpio_setup_io()
508 		return -EINVAL;  in bgpio_setup_io()
511 		gc->reg_set = set;  in bgpio_setup_io()
512 		gc->reg_clr = clr;  in bgpio_setup_io()
513 		gc->set = bgpio_set_with_clear;  in bgpio_setup_io()
514 		gc->set_multiple = bgpio_set_multiple_with_clear;  in bgpio_setup_io()
516 		gc->reg_set = set;  in bgpio_setup_io()
517 		gc->set = bgpio_set_set;  in bgpio_setup_io()
518 		gc->set_multiple = bgpio_set_multiple_set;  in bgpio_setup_io()
520 		gc->set = bgpio_set_none;  in bgpio_setup_io()
521 		gc->set_multiple = NULL;  in bgpio_setup_io()
523 		gc->set = bgpio_set;  in bgpio_setup_io()
524 		gc->set_multiple = bgpio_set_multiple;  in bgpio_setup_io()
529 		gc->get = bgpio_get_set;  in bgpio_setup_io()
530 		if (!gc->be_bits)  in bgpio_setup_io()
531 			gc->get_multiple = bgpio_get_set_multiple;  in bgpio_setup_io()
533 		 * We deliberately avoid assigning the ->get_multiple() call  in bgpio_setup_io()
536 		 * simply too much complexity, let the GPIO core fall back to  in bgpio_setup_io()
540 		gc->get = bgpio_get;  in bgpio_setup_io()
541 		if (gc->be_bits)  in bgpio_setup_io()
542 			gc->get_multiple = bgpio_get_multiple_be;  in bgpio_setup_io()
544 			gc->get_multiple = bgpio_get_multiple;  in bgpio_setup_io()
556 		gc->reg_dir_out = dirout;  in bgpio_setup_direction()
557 		gc->reg_dir_in = dirin;  in bgpio_setup_direction()
559 			gc->direction_output = bgpio_dir_out_dir_first;  in bgpio_setup_direction()
561 			gc->direction_output = bgpio_dir_out_val_first;  in bgpio_setup_direction()
562 		gc->direction_input = bgpio_dir_in;  in bgpio_setup_direction()
563 		gc->get_direction = bgpio_get_dir;  in bgpio_setup_direction()
566 			gc->direction_output = bgpio_dir_out_err;  in bgpio_setup_direction()
568 			gc->direction_output = bgpio_simple_dir_out;  in bgpio_setup_direction()
569 		gc->direction_input = bgpio_simple_dir_in;  in bgpio_setup_direction()
577 	if (gpio_pin >= chip->ngpio)  in bgpio_request()
578 		return -EINVAL;  in bgpio_request()
580 	if (chip->bgpio_pinctrl)  in bgpio_request()
587  * bgpio_init() - Initialize generic GPIO accessor functions
588  * @gc: the GPIO chip to set up
589  * @dev: the parent device of the new GPIO chip (compulsory)
591  * @dat: MMIO address for the register to READ the value of the GPIO lines, it
594  * @set: MMIO address for the register to SET the value of the GPIO lines, it is
595  *	expected that we write the line with 1 in this register to drive the GPIO line
597  * @clr: MMIO address for the register to CLEAR the value of the GPIO lines, it is
598  *	expected that we write the line with 1 in this register to drive the GPIO line
600  *	will be assumed to also clear the GPIO lines, by actively writing the line
621 		return -EINVAL;  in bgpio_init()
623 	gc->bgpio_bits = sz * 8;  in bgpio_init()
624 	if (gc->bgpio_bits > BITS_PER_LONG)  in bgpio_init()
625 		return -EINVAL;  in bgpio_init()
627 	raw_spin_lock_init(&gc->bgpio_lock);  in bgpio_init()
628 	gc->parent = dev;  in bgpio_init()
629 	gc->label = dev_name(dev);  in bgpio_init()
630 	gc->base = -1;  in bgpio_init()
631 	gc->request = bgpio_request;  in bgpio_init()
632 	gc->be_bits = !!(flags & BGPIOF_BIG_ENDIAN);  in bgpio_init()
636 		gc->ngpio = gc->bgpio_bits;  in bgpio_init()
651 		gc->bgpio_pinctrl = true;  in bgpio_init()
653 		gc->free = gpiochip_generic_free;  in bgpio_init()
656 	gc->bgpio_data = gc->read_reg(gc->reg_dat);  in bgpio_init()
657 	if (gc->set == bgpio_set_set &&  in bgpio_init()
659 		gc->bgpio_data = gc->read_reg(gc->reg_set);  in bgpio_init()
662 		gc->bgpio_dir_unreadable = true;  in bgpio_init()
667 	if ((gc->reg_dir_out || gc->reg_dir_in) &&  in bgpio_init()
669 		if (gc->reg_dir_out)  in bgpio_init()
670 			gc->bgpio_dir = gc->read_reg(gc->reg_dir_out);  in bgpio_init()
671 		else if (gc->reg_dir_in)  in bgpio_init()
672 			gc->bgpio_dir = ~gc->read_reg(gc->reg_dir_in);  in bgpio_init()
679 		if (gc->reg_dir_out && gc->reg_dir_in)  in bgpio_init()
680 			gc->write_reg(gc->reg_dir_in, ~gc->bgpio_dir);  in bgpio_init()
702 		return IOMEM_ERR_PTR(-EINVAL);  in bgpio_map()
704 	return devm_ioremap_resource(&pdev->dev, r);  in bgpio_map()
708 	{ .compatible = "brcm,bcm6345-gpio" },
709 	{ .compatible = "wd,mbl-gpio" },
710 	{ .compatible = "ni,169445-nand-gpio" },
724 		return ERR_PTR(-ENOMEM);  in bgpio_parse_fw()
726 	pdata->base = -1;  in bgpio_parse_fw()
731 	if (device_property_read_bool(dev, "no-output"))  in bgpio_parse_fw()
739 	struct device *dev = &pdev->dev;  in bgpio_pdev_probe()
758 		flags = pdev->id_entry->driver_data;  in bgpio_pdev_probe()
763 		return -EINVAL;  in bgpio_pdev_probe()
787 	gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);  in bgpio_pdev_probe()
789 		return -ENOMEM;  in bgpio_pdev_probe()
796 		if (pdata->label)  in bgpio_pdev_probe()
797 			gc->label = pdata->label;  in bgpio_pdev_probe()
798 		gc->base = pdata->base;  in bgpio_pdev_probe()
799 		if (pdata->ngpio > 0)  in bgpio_pdev_probe()
800 			gc->ngpio = pdata->ngpio;  in bgpio_pdev_probe()
805 	return devm_gpiochip_add_data(&pdev->dev, gc, NULL);  in bgpio_pdev_probe()
810 		.name		= "basic-mmio-gpio",
813 		.name		= "basic-mmio-gpio-be",
822 		.name = "basic-mmio-gpio",
833 MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers");