Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2)  * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *	Andrew F. Davis <afd@ti.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * This program is free software; you can redistribute it and/or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * modify it under the terms of the GNU General Public License version 2 as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * published by the Free Software Foundation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  * kind, whether expressed or implied; without even the implied warranty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  * GNU General Public License version 2 for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/bitmap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/bitops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/delay.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/gpio/consumer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/gpio/driver.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <linux/spi/spi.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #define DEFAULT_NGPIO 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27)  * struct pisosr_gpio - GPIO driver data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28)  * @chip: GPIO controller chip
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29)  * @spi: SPI device pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30)  * @buffer: Buffer for device reads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31)  * @buffer_size: Size of buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32)  * @load_gpio: GPIO pin used to load input into device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33)  * @lock: Protects read sequences
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) struct pisosr_gpio {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	struct gpio_chip chip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	struct spi_device *spi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	u8 *buffer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	size_t buffer_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	struct gpio_desc *load_gpio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	struct mutex lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) static int pisosr_gpio_refresh(struct pisosr_gpio *gpio)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	mutex_lock(&gpio->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	if (gpio->load_gpio) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 		gpiod_set_value_cansleep(gpio->load_gpio, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		udelay(1); /* registers load time (~10ns) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 		gpiod_set_value_cansleep(gpio->load_gpio, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 		udelay(1); /* registers recovery time (~5ns) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	ret = spi_read(gpio->spi, gpio->buffer, gpio->buffer_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	mutex_unlock(&gpio->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) static int pisosr_gpio_get_direction(struct gpio_chip *chip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 				     unsigned offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	/* This device always input */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	return GPIO_LINE_DIRECTION_IN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) static int pisosr_gpio_direction_input(struct gpio_chip *chip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 				       unsigned offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	/* This device always input */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) static int pisosr_gpio_direction_output(struct gpio_chip *chip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 					unsigned offset, int value)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	/* This device is input only */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) static int pisosr_gpio_get(struct gpio_chip *chip, unsigned offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	struct pisosr_gpio *gpio = gpiochip_get_data(chip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	/* Refresh may not always be needed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	pisosr_gpio_refresh(gpio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	return (gpio->buffer[offset / 8] >> (offset % 8)) & 0x1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) static int pisosr_gpio_get_multiple(struct gpio_chip *chip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 				    unsigned long *mask, unsigned long *bits)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	struct pisosr_gpio *gpio = gpiochip_get_data(chip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	unsigned long offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	unsigned long gpio_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	unsigned long buffer_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	pisosr_gpio_refresh(gpio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	bitmap_zero(bits, chip->ngpio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	for_each_set_clump8(offset, gpio_mask, mask, chip->ngpio) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 		buffer_state = gpio->buffer[offset / 8] & gpio_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 		bitmap_set_value8(bits, buffer_state, offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) static const struct gpio_chip template_chip = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	.label			= "pisosr-gpio",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	.owner			= THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	.get_direction		= pisosr_gpio_get_direction,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	.direction_input	= pisosr_gpio_direction_input,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	.direction_output	= pisosr_gpio_direction_output,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	.get			= pisosr_gpio_get,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	.get_multiple		= pisosr_gpio_get_multiple,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	.base			= -1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	.ngpio			= DEFAULT_NGPIO,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	.can_sleep		= true,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) static int pisosr_gpio_probe(struct spi_device *spi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	struct device *dev = &spi->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	struct pisosr_gpio *gpio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	if (!gpio)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	spi_set_drvdata(spi, gpio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	gpio->chip = template_chip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	gpio->chip.parent = dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	of_property_read_u16(dev->of_node, "ngpios", &gpio->chip.ngpio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	gpio->spi = spi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	gpio->buffer_size = DIV_ROUND_UP(gpio->chip.ngpio, 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	gpio->buffer = devm_kzalloc(dev, gpio->buffer_size, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	if (!gpio->buffer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	gpio->load_gpio = devm_gpiod_get_optional(dev, "load", GPIOD_OUT_LOW);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	if (IS_ERR(gpio->load_gpio))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 		return dev_err_probe(dev, PTR_ERR(gpio->load_gpio),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 				     "Unable to allocate load GPIO\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	mutex_init(&gpio->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	ret = gpiochip_add_data(&gpio->chip, gpio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		dev_err(dev, "Unable to register gpiochip\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) static int pisosr_gpio_remove(struct spi_device *spi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	struct pisosr_gpio *gpio = spi_get_drvdata(spi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	gpiochip_remove(&gpio->chip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	mutex_destroy(&gpio->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) static const struct spi_device_id pisosr_gpio_id_table[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	{ "pisosr-gpio", },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	{ /* sentinel */ }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) MODULE_DEVICE_TABLE(spi, pisosr_gpio_id_table);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) static const struct of_device_id pisosr_gpio_of_match_table[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	{ .compatible = "pisosr-gpio", },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	{ /* sentinel */ }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) MODULE_DEVICE_TABLE(of, pisosr_gpio_of_match_table);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) static struct spi_driver pisosr_gpio_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	.driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 		.name = "pisosr-gpio",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		.of_match_table = pisosr_gpio_of_match_table,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	.probe = pisosr_gpio_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	.remove = pisosr_gpio_remove,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	.id_table = pisosr_gpio_id_table,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) module_spi_driver(pisosr_gpio_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) MODULE_DESCRIPTION("SPI Compatible PISO Shift Register GPIO Driver");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) MODULE_LICENSE("GPL v2");