2  *  74Hx164 - Generic serial-in/parallel-out 8-bits shift register GPIO driver
14 #include <linux/spi/spi.h>
15 #include <linux/spi/74x164.h>
16 #include <linux/gpio.h>
21 	struct spi_device	*spi;  member
34 	return spi_write(chip->spi,  in __gen_74x164_write_config()
35 			 &chip->port_config, sizeof(chip->port_config));  in __gen_74x164_write_config()
43 	mutex_lock(&chip->lock);  in gen_74x164_get_value()
44 	ret = (chip->port_config >> offset) & 0x1;  in gen_74x164_get_value()
45 	mutex_unlock(&chip->lock);  in gen_74x164_get_value()
55 	mutex_lock(&chip->lock);  in gen_74x164_set_value()
57 		chip->port_config |= (1 << offset);  in gen_74x164_set_value()
59 		chip->port_config &= ~(1 << offset);  in gen_74x164_set_value()
62 	mutex_unlock(&chip->lock);  in gen_74x164_set_value()
72 static int __devinit gen_74x164_probe(struct spi_device *spi)  in gen_74x164_probe()  argument
78 	pdata = spi->dev.platform_data;  in gen_74x164_probe()
79 	if (!pdata || !pdata->base) {  in gen_74x164_probe()
80 		dev_dbg(&spi->dev, "incorrect or missing platform data\n");  in gen_74x164_probe()
81 		return -EINVAL;  in gen_74x164_probe()
87 	spi->bits_per_word = 8;  in gen_74x164_probe()
89 	ret = spi_setup(spi);  in gen_74x164_probe()
95 		return -ENOMEM;  in gen_74x164_probe()
97 	mutex_init(&chip->lock);  in gen_74x164_probe()
99 	dev_set_drvdata(&spi->dev, chip);  in gen_74x164_probe()
101 	chip->spi = spi;  in gen_74x164_probe()
103 	chip->gpio_chip.label = spi->modalias;  in gen_74x164_probe()
104 	chip->gpio_chip.direction_output = gen_74x164_direction_output;  in gen_74x164_probe()
105 	chip->gpio_chip.get = gen_74x164_get_value;  in gen_74x164_probe()
106 	chip->gpio_chip.set = gen_74x164_set_value;  in gen_74x164_probe()
107 	chip->gpio_chip.base = pdata->base;  in gen_74x164_probe()
108 	chip->gpio_chip.ngpio = 8;  in gen_74x164_probe()
109 	chip->gpio_chip.can_sleep = 1;  in gen_74x164_probe()
110 	chip->gpio_chip.dev = &spi->dev;  in gen_74x164_probe()
111 	chip->gpio_chip.owner = THIS_MODULE;  in gen_74x164_probe()
115 		dev_err(&spi->dev, "Failed writing: %d\n", ret);  in gen_74x164_probe()
119 	ret = gpiochip_add(&chip->gpio_chip);  in gen_74x164_probe()
126 	dev_set_drvdata(&spi->dev, NULL);  in gen_74x164_probe()
127 	mutex_destroy(&chip->lock);  in gen_74x164_probe()
132 static int __devexit gen_74x164_remove(struct spi_device *spi)  in gen_74x164_remove()  argument
137 	chip = dev_get_drvdata(&spi->dev);  in gen_74x164_remove()
139 		return -ENODEV;  in gen_74x164_remove()
141 	dev_set_drvdata(&spi->dev, NULL);  in gen_74x164_remove()
143 	ret = gpiochip_remove(&chip->gpio_chip);  in gen_74x164_remove()
145 		mutex_destroy(&chip->lock);  in gen_74x164_remove()
148 		dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",  in gen_74x164_remove()
177 MODULE_DESCRIPTION("GPIO expander driver for 74X164 8-bits shift register");