1 // SPDX-License-Identifier: GPL-2.0-only
3  *  74Hx164 - Generic serial-in/parallel-out 8-bits shift register GPIO driver
22 	struct mutex		lock;  member
37 	return spi_write(to_spi_device(chip->gpio_chip.parent), chip->buffer,  in __gen_74x164_write_config()
38 			 chip->registers);  in __gen_74x164_write_config()
41 static int gen_74x164_get_value(struct gpio_chip *gc, unsigned offset)  in gen_74x164_get_value()  argument
44 	u8 bank = chip->registers - 1 - offset / 8;  in gen_74x164_get_value()
45 	u8 pin = offset % 8;  in gen_74x164_get_value()
48 	mutex_lock(&chip->lock);  in gen_74x164_get_value()
49 	ret = (chip->buffer[bank] >> pin) & 0x1;  in gen_74x164_get_value()
50 	mutex_unlock(&chip->lock);  in gen_74x164_get_value()
56 		unsigned offset, int val)  in gen_74x164_set_value()  argument
59 	u8 bank = chip->registers - 1 - offset / 8;  in gen_74x164_set_value()
60 	u8 pin = offset % 8;  in gen_74x164_set_value()
62 	mutex_lock(&chip->lock);  in gen_74x164_set_value()
64 		chip->buffer[bank] |= (1 << pin);  in gen_74x164_set_value()
66 		chip->buffer[bank] &= ~(1 << pin);  in gen_74x164_set_value()
69 	mutex_unlock(&chip->lock);  in gen_74x164_set_value()
76 	unsigned long offset;  in gen_74x164_set_multiple()  local
81 	mutex_lock(&chip->lock);  in gen_74x164_set_multiple()
82 	for_each_set_clump8(offset, bankmask, mask, chip->registers * 8) {  in gen_74x164_set_multiple()
83 		bank = chip->registers - 1 - offset / 8;  in gen_74x164_set_multiple()
84 		bitmask = bitmap_get_value8(bits, offset) & bankmask;  in gen_74x164_set_multiple()
86 		chip->buffer[bank] &= ~bankmask;  in gen_74x164_set_multiple()
87 		chip->buffer[bank] |= bitmask;  in gen_74x164_set_multiple()
90 	mutex_unlock(&chip->lock);  in gen_74x164_set_multiple()
94 		unsigned offset, int val)  in gen_74x164_direction_output()  argument
96 	gen_74x164_set_value(gc, offset, val);  in gen_74x164_direction_output()
109 	spi->bits_per_word = 8;  in gen_74x164_probe()
115 	ret = device_property_read_u32(&spi->dev, "registers-number", &nregs);  in gen_74x164_probe()
117 		dev_err(&spi->dev, "Missing 'registers-number' property.\n");  in gen_74x164_probe()
118 		return -EINVAL;  in gen_74x164_probe()
121 	chip = devm_kzalloc(&spi->dev, sizeof(*chip) + nregs, GFP_KERNEL);  in gen_74x164_probe()
123 		return -ENOMEM;  in gen_74x164_probe()
125 	chip->gpiod_oe = devm_gpiod_get_optional(&spi->dev, "enable",  in gen_74x164_probe()
127 	if (IS_ERR(chip->gpiod_oe))  in gen_74x164_probe()
128 		return PTR_ERR(chip->gpiod_oe);  in gen_74x164_probe()
132 	chip->gpio_chip.label = spi->modalias;  in gen_74x164_probe()
133 	chip->gpio_chip.direction_output = gen_74x164_direction_output;  in gen_74x164_probe()
134 	chip->gpio_chip.get = gen_74x164_get_value;  in gen_74x164_probe()
135 	chip->gpio_chip.set = gen_74x164_set_value;  in gen_74x164_probe()
136 	chip->gpio_chip.set_multiple = gen_74x164_set_multiple;  in gen_74x164_probe()
137 	chip->gpio_chip.base = -1;  in gen_74x164_probe()
139 	chip->registers = nregs;  in gen_74x164_probe()
140 	chip->gpio_chip.ngpio = GEN_74X164_NUMBER_GPIOS * chip->registers;  in gen_74x164_probe()
142 	chip->gpio_chip.can_sleep = true;  in gen_74x164_probe()
143 	chip->gpio_chip.parent = &spi->dev;  in gen_74x164_probe()
144 	chip->gpio_chip.owner = THIS_MODULE;  in gen_74x164_probe()
146 	mutex_init(&chip->lock);  in gen_74x164_probe()
150 		dev_err(&spi->dev, "Failed writing: %d\n", ret);  in gen_74x164_probe()
154 	gpiod_set_value_cansleep(chip->gpiod_oe, 1);  in gen_74x164_probe()
156 	ret = gpiochip_add_data(&chip->gpio_chip, chip);  in gen_74x164_probe()
161 	mutex_destroy(&chip->lock);  in gen_74x164_probe()
170 	gpiod_set_value_cansleep(chip->gpiod_oe, 0);  in gen_74x164_remove()
171 	gpiochip_remove(&chip->gpio_chip);  in gen_74x164_remove()
172 	mutex_destroy(&chip->lock);  in gen_74x164_remove()
202 MODULE_DESCRIPTION("GPIO expander driver for 74X164 8-bits shift register");