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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Xilinx gpio driver for xps/axi_gpio IP.
- *
- * Copyright 2008 - 2013 Xilinx, Inc.
- */
- #include <linux/bitops.h>
- #include <linux/init.h>
- #include <linux/errno.h>
- #include <linux/module.h>
- #include <linux/of_device.h>
- #include <linux/of_platform.h>
- #include <linux/io.h>
- #include <linux/gpio/driver.h>
- #include <linux/slab.h>
- /* Register Offset Definitions */
- #define XGPIO_DATA_OFFSET (0x0) /* Data register */
- #define XGPIO_TRI_OFFSET (0x4) /* I/O direction register */
- #define XGPIO_CHANNEL_OFFSET 0x8
- /* Read/Write access to the GPIO registers */
- #if defined(CONFIG_ARCH_ZYNQ) || defined(CONFIG_X86)
- # define xgpio_readreg(offset) readl(offset)
- # define xgpio_writereg(offset, val) writel(val, offset)
- #else
- # define xgpio_readreg(offset) __raw_readl(offset)
- # define xgpio_writereg(offset, val) __raw_writel(val, offset)
- #endif
- /**
- * struct xgpio_instance - Stores information about GPIO device
- * @gc: GPIO chip
- * @regs: register block
- * @gpio_width: GPIO width for every channel
- * @gpio_state: GPIO state shadow register
- * @gpio_dir: GPIO direction shadow register
- * @gpio_lock: Lock used for synchronization
- */
- struct xgpio_instance {
- struct gpio_chip gc;
- void __iomem *regs;
- unsigned int gpio_width[2];
- u32 gpio_state[2];
- u32 gpio_dir[2];
- spinlock_t gpio_lock[2];
- };
- static inline int xgpio_index(struct xgpio_instance *chip, int gpio)
- {
- if (gpio >= chip->gpio_width[0])
- return 1;
- return 0;
- }
- static inline int xgpio_regoffset(struct xgpio_instance *chip, int gpio)
- {
- if (xgpio_index(chip, gpio))
- return XGPIO_CHANNEL_OFFSET;
- return 0;
- }
- static inline int xgpio_offset(struct xgpio_instance *chip, int gpio)
- {
- if (xgpio_index(chip, gpio))
- return gpio - chip->gpio_width[0];
- return gpio;
- }
- /**
- * xgpio_get - Read the specified signal of the GPIO device.
- * @gc: Pointer to gpio_chip device structure.
- * @gpio: GPIO signal number.
- *
- * This function reads the specified signal of the GPIO device.
- *
- * Return:
- * 0 if direction of GPIO signals is set as input otherwise it
- * returns negative error value.
- */
- static int xgpio_get(struct gpio_chip *gc, unsigned int gpio)
- {
- struct xgpio_instance *chip = gpiochip_get_data(gc);
- u32 val;
- val = xgpio_readreg(chip->regs + XGPIO_DATA_OFFSET +
- xgpio_regoffset(chip, gpio));
- return !!(val & BIT(xgpio_offset(chip, gpio)));
- }
- /**
- * xgpio_set - Write the specified signal of the GPIO device.
- * @gc: Pointer to gpio_chip device structure.
- * @gpio: GPIO signal number.
- * @val: Value to be written to specified signal.
- *
- * This function writes the specified value in to the specified signal of the
- * GPIO device.
- */
- static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
- {
- unsigned long flags;
- struct xgpio_instance *chip = gpiochip_get_data(gc);
- int index = xgpio_index(chip, gpio);
- int offset = xgpio_offset(chip, gpio);
- spin_lock_irqsave(&chip->gpio_lock[index], flags);
- /* Write to GPIO signal and set its direction to output */
- if (val)
- chip->gpio_state[index] |= BIT(offset);
- else
- chip->gpio_state[index] &= ~BIT(offset);
- xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
- xgpio_regoffset(chip, gpio), chip->gpio_state[index]);
- spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
- }
- /**
- * xgpio_set_multiple - Write the specified signals of the GPIO device.
- * @gc: Pointer to gpio_chip device structure.
- * @mask: Mask of the GPIOS to modify.
- * @bits: Value to be wrote on each GPIO
- *
- * This function writes the specified values into the specified signals of the
- * GPIO devices.
- */
- static void xgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
- unsigned long *bits)
- {
- unsigned long flags;
- struct xgpio_instance *chip = gpiochip_get_data(gc);
- int index = xgpio_index(chip, 0);
- int offset, i;
- spin_lock_irqsave(&chip->gpio_lock[index], flags);
- /* Write to GPIO signals */
- for (i = 0; i < gc->ngpio; i++) {
- if (*mask == 0)
- break;
- /* Once finished with an index write it out to the register */
- if (index != xgpio_index(chip, i)) {
- xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
- index * XGPIO_CHANNEL_OFFSET,
- chip->gpio_state[index]);
- spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
- index = xgpio_index(chip, i);
- spin_lock_irqsave(&chip->gpio_lock[index], flags);
- }
- if (__test_and_clear_bit(i, mask)) {
- offset = xgpio_offset(chip, i);
- if (test_bit(i, bits))
- chip->gpio_state[index] |= BIT(offset);
- else
- chip->gpio_state[index] &= ~BIT(offset);
- }
- }
- xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
- index * XGPIO_CHANNEL_OFFSET, chip->gpio_state[index]);
- spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
- }
- /**
- * xgpio_dir_in - Set the direction of the specified GPIO signal as input.
- * @gc: Pointer to gpio_chip device structure.
- * @gpio: GPIO signal number.
- *
- * Return:
- * 0 - if direction of GPIO signals is set as input
- * otherwise it returns negative error value.
- */
- static int xgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
- {
- unsigned long flags;
- struct xgpio_instance *chip = gpiochip_get_data(gc);
- int index = xgpio_index(chip, gpio);
- int offset = xgpio_offset(chip, gpio);
- spin_lock_irqsave(&chip->gpio_lock[index], flags);
- /* Set the GPIO bit in shadow register and set direction as input */
- chip->gpio_dir[index] |= BIT(offset);
- xgpio_writereg(chip->regs + XGPIO_TRI_OFFSET +
- xgpio_regoffset(chip, gpio), chip->gpio_dir[index]);
- spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
- return 0;
- }
- /**
- * xgpio_dir_out - Set the direction of the specified GPIO signal as output.
- * @gc: Pointer to gpio_chip device structure.
- * @gpio: GPIO signal number.
- * @val: Value to be written to specified signal.
- *
- * This function sets the direction of specified GPIO signal as output.
- *
- * Return:
- * If all GPIO signals of GPIO chip is configured as input then it returns
- * error otherwise it returns 0.
- */
- static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
- {
- unsigned long flags;
- struct xgpio_instance *chip = gpiochip_get_data(gc);
- int index = xgpio_index(chip, gpio);
- int offset = xgpio_offset(chip, gpio);
- spin_lock_irqsave(&chip->gpio_lock[index], flags);
- /* Write state of GPIO signal */
- if (val)
- chip->gpio_state[index] |= BIT(offset);
- else
- chip->gpio_state[index] &= ~BIT(offset);
- xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET +
- xgpio_regoffset(chip, gpio), chip->gpio_state[index]);
- /* Clear the GPIO bit in shadow register and set direction as output */
- chip->gpio_dir[index] &= ~BIT(offset);
- xgpio_writereg(chip->regs + XGPIO_TRI_OFFSET +
- xgpio_regoffset(chip, gpio), chip->gpio_dir[index]);
- spin_unlock_irqrestore(&chip->gpio_lock[index], flags);
- return 0;
- }
- /**
- * xgpio_save_regs - Set initial values of GPIO pins
- * @chip: Pointer to GPIO instance
- */
- static void xgpio_save_regs(struct xgpio_instance *chip)
- {
- xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET, chip->gpio_state[0]);
- xgpio_writereg(chip->regs + XGPIO_TRI_OFFSET, chip->gpio_dir[0]);
- if (!chip->gpio_width[1])
- return;
- xgpio_writereg(chip->regs + XGPIO_DATA_OFFSET + XGPIO_CHANNEL_OFFSET,
- chip->gpio_state[1]);
- xgpio_writereg(chip->regs + XGPIO_TRI_OFFSET + XGPIO_CHANNEL_OFFSET,
- chip->gpio_dir[1]);
- }
- /**
- * xgpio_of_probe - Probe method for the GPIO device.
- * @pdev: pointer to the platform device
- *
- * Return:
- * It returns 0, if the driver is bound to the GPIO device, or
- * a negative value if there is an error.
- */
- static int xgpio_probe(struct platform_device *pdev)
- {
- struct xgpio_instance *chip;
- int status = 0;
- struct device_node *np = pdev->dev.of_node;
- u32 is_dual;
- chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
- if (!chip)
- return -ENOMEM;
- platform_set_drvdata(pdev, chip);
- /* Update GPIO state shadow register with default value */
- of_property_read_u32(np, "xlnx,dout-default", &chip->gpio_state[0]);
- /* Update GPIO direction shadow register with default value */
- if (of_property_read_u32(np, "xlnx,tri-default", &chip->gpio_dir[0]))
- chip->gpio_dir[0] = 0xFFFFFFFF;
- /*
- * Check device node and parent device node for device width
- * and assume default width of 32
- */
- if (of_property_read_u32(np, "xlnx,gpio-width", &chip->gpio_width[0]))
- chip->gpio_width[0] = 32;
- spin_lock_init(&chip->gpio_lock[0]);
- if (of_property_read_u32(np, "xlnx,is-dual", &is_dual))
- is_dual = 0;
- if (is_dual) {
- /* Update GPIO state shadow register with default value */
- of_property_read_u32(np, "xlnx,dout-default-2",
- &chip->gpio_state[1]);
- /* Update GPIO direction shadow register with default value */
- if (of_property_read_u32(np, "xlnx,tri-default-2",
- &chip->gpio_dir[1]))
- chip->gpio_dir[1] = 0xFFFFFFFF;
- /*
- * Check device node and parent device node for device width
- * and assume default width of 32
- */
- if (of_property_read_u32(np, "xlnx,gpio2-width",
- &chip->gpio_width[1]))
- chip->gpio_width[1] = 32;
- spin_lock_init(&chip->gpio_lock[1]);
- }
- chip->gc.base = -1;
- chip->gc.ngpio = chip->gpio_width[0] + chip->gpio_width[1];
- chip->gc.parent = &pdev->dev;
- chip->gc.direction_input = xgpio_dir_in;
- chip->gc.direction_output = xgpio_dir_out;
- chip->gc.get = xgpio_get;
- chip->gc.set = xgpio_set;
- chip->gc.set_multiple = xgpio_set_multiple;
- chip->gc.label = dev_name(&pdev->dev);
- chip->regs = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(chip->regs)) {
- dev_err(&pdev->dev, "failed to ioremap memory resource\n");
- return PTR_ERR(chip->regs);
- }
- xgpio_save_regs(chip);
- status = devm_gpiochip_add_data(&pdev->dev, &chip->gc, chip);
- if (status) {
- dev_err(&pdev->dev, "failed to add GPIO chip\n");
- return status;
- }
- return 0;
- }
- static const struct of_device_id xgpio_of_match[] = {
- { .compatible = "xlnx,xps-gpio-1.00.a", },
- { /* end of list */ },
- };
- MODULE_DEVICE_TABLE(of, xgpio_of_match);
- static struct platform_driver xgpio_plat_driver = {
- .probe = xgpio_probe,
- .driver = {
- .name = "gpio-xilinx",
- .of_match_table = xgpio_of_match,
- },
- };
- static int __init xgpio_init(void)
- {
- return platform_driver_register(&xgpio_plat_driver);
- }
- subsys_initcall(xgpio_init);
- static void __exit xgpio_exit(void)
- {
- platform_driver_unregister(&xgpio_plat_driver);
- }
- module_exit(xgpio_exit);
- MODULE_AUTHOR("Xilinx, Inc.");
- MODULE_DESCRIPTION("Xilinx GPIO driver");
- MODULE_LICENSE("GPL");
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