| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * GPIO Testing Device Driver |
| * |
| * Copyright (C) 2014 Kamlakant Patel <kamlakant.patel@broadcom.com> |
| * Copyright (C) 2015-2016 Bamvor Jian Zhang <bamv2005@gmail.com> |
| * Copyright (C) 2017 Bartosz Golaszewski <brgl@bgdev.pl> |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/gpio/driver.h> |
| #include <linux/gpio/consumer.h> |
| #include <linux/platform_device.h> |
| #include <linux/slab.h> |
| #include <linux/interrupt.h> |
| #include <linux/irq.h> |
| #include <linux/irq_sim.h> |
| #include <linux/debugfs.h> |
| #include <linux/uaccess.h> |
| #include <linux/property.h> |
| |
| #include "gpiolib.h" |
| |
| #define GPIO_MOCKUP_NAME "gpio-mockup" |
| #define GPIO_MOCKUP_MAX_GC 10 |
| /* |
| * We're storing two values per chip: the GPIO base and the number |
| * of GPIO lines. |
| */ |
| #define GPIO_MOCKUP_MAX_RANGES (GPIO_MOCKUP_MAX_GC * 2) |
| /* Maximum of three properties + the sentinel. */ |
| #define GPIO_MOCKUP_MAX_PROP 4 |
| |
| #define gpio_mockup_err(...) pr_err(GPIO_MOCKUP_NAME ": " __VA_ARGS__) |
| |
| enum { |
| GPIO_MOCKUP_DIR_OUT = 0, |
| GPIO_MOCKUP_DIR_IN = 1, |
| }; |
| |
| /* |
| * struct gpio_pin_status - structure describing a GPIO status |
| * @dir: Configures direction of gpio as "in" or "out", 0=in, 1=out |
| * @value: Configures status of the gpio as 0(low) or 1(high) |
| */ |
| struct gpio_mockup_line_status { |
| int dir; |
| int value; |
| }; |
| |
| struct gpio_mockup_chip { |
| struct gpio_chip gc; |
| struct gpio_mockup_line_status *lines; |
| struct irq_sim irqsim; |
| struct dentry *dbg_dir; |
| }; |
| |
| struct gpio_mockup_dbgfs_private { |
| struct gpio_mockup_chip *chip; |
| struct gpio_desc *desc; |
| int offset; |
| }; |
| |
| static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_RANGES]; |
| static int gpio_mockup_num_ranges; |
| module_param_array(gpio_mockup_ranges, int, &gpio_mockup_num_ranges, 0400); |
| |
| static bool gpio_mockup_named_lines; |
| module_param_named(gpio_mockup_named_lines, |
| gpio_mockup_named_lines, bool, 0400); |
| |
| static struct dentry *gpio_mockup_dbg_dir; |
| |
| static int gpio_mockup_range_base(unsigned int index) |
| { |
| return gpio_mockup_ranges[index * 2]; |
| } |
| |
| static int gpio_mockup_range_ngpio(unsigned int index) |
| { |
| return gpio_mockup_ranges[index * 2 + 1]; |
| } |
| |
| static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset) |
| { |
| struct gpio_mockup_chip *chip = gpiochip_get_data(gc); |
| |
| return chip->lines[offset].value; |
| } |
| |
| static void gpio_mockup_set(struct gpio_chip *gc, |
| unsigned int offset, int value) |
| { |
| struct gpio_mockup_chip *chip = gpiochip_get_data(gc); |
| |
| chip->lines[offset].value = !!value; |
| } |
| |
| static void gpio_mockup_set_multiple(struct gpio_chip *gc, |
| unsigned long *mask, unsigned long *bits) |
| { |
| unsigned int bit; |
| |
| for_each_set_bit(bit, mask, gc->ngpio) |
| gpio_mockup_set(gc, bit, test_bit(bit, bits)); |
| |
| } |
| |
| static int gpio_mockup_dirout(struct gpio_chip *gc, |
| unsigned int offset, int value) |
| { |
| struct gpio_mockup_chip *chip = gpiochip_get_data(gc); |
| |
| gpio_mockup_set(gc, offset, value); |
| chip->lines[offset].dir = GPIO_MOCKUP_DIR_OUT; |
| |
| return 0; |
| } |
| |
| static int gpio_mockup_dirin(struct gpio_chip *gc, unsigned int offset) |
| { |
| struct gpio_mockup_chip *chip = gpiochip_get_data(gc); |
| |
| chip->lines[offset].dir = GPIO_MOCKUP_DIR_IN; |
| |
| return 0; |
| } |
| |
| static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset) |
| { |
| struct gpio_mockup_chip *chip = gpiochip_get_data(gc); |
| |
| return chip->lines[offset].dir; |
| } |
| |
| static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset) |
| { |
| struct gpio_mockup_chip *chip = gpiochip_get_data(gc); |
| |
| return irq_sim_irqnum(&chip->irqsim, offset); |
| } |
| |
| static ssize_t gpio_mockup_event_write(struct file *file, |
| const char __user *usr_buf, |
| size_t size, loff_t *ppos) |
| { |
| struct gpio_mockup_dbgfs_private *priv; |
| struct gpio_mockup_chip *chip; |
| struct seq_file *sfile; |
| struct gpio_desc *desc; |
| int rv, val; |
| |
| rv = kstrtoint_from_user(usr_buf, size, 0, &val); |
| if (rv) |
| return rv; |
| if (val != 0 && val != 1) |
| return -EINVAL; |
| |
| sfile = file->private_data; |
| priv = sfile->private; |
| desc = priv->desc; |
| chip = priv->chip; |
| |
| gpiod_set_value_cansleep(desc, val); |
| irq_sim_fire(&chip->irqsim, priv->offset); |
| |
| return size; |
| } |
| |
| static int gpio_mockup_event_open(struct inode *inode, struct file *file) |
| { |
| return single_open(file, NULL, inode->i_private); |
| } |
| |
| static const struct file_operations gpio_mockup_event_ops = { |
| .owner = THIS_MODULE, |
| .open = gpio_mockup_event_open, |
| .write = gpio_mockup_event_write, |
| .llseek = no_llseek, |
| }; |
| |
| static void gpio_mockup_debugfs_setup(struct device *dev, |
| struct gpio_mockup_chip *chip) |
| { |
| struct gpio_mockup_dbgfs_private *priv; |
| struct dentry *evfile, *link; |
| struct gpio_chip *gc; |
| const char *devname; |
| char *name; |
| int i; |
| |
| gc = &chip->gc; |
| devname = dev_name(&gc->gpiodev->dev); |
| |
| chip->dbg_dir = debugfs_create_dir(devname, gpio_mockup_dbg_dir); |
| if (IS_ERR_OR_NULL(chip->dbg_dir)) |
| goto err; |
| |
| link = debugfs_create_symlink(gc->label, gpio_mockup_dbg_dir, devname); |
| if (IS_ERR_OR_NULL(link)) |
| goto err; |
| |
| for (i = 0; i < gc->ngpio; i++) { |
| name = devm_kasprintf(dev, GFP_KERNEL, "%d", i); |
| if (!name) |
| goto err; |
| |
| priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); |
| if (!priv) |
| goto err; |
| |
| priv->chip = chip; |
| priv->offset = i; |
| priv->desc = &gc->gpiodev->descs[i]; |
| |
| evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv, |
| &gpio_mockup_event_ops); |
| if (IS_ERR_OR_NULL(evfile)) |
| goto err; |
| } |
| |
| return; |
| |
| err: |
| dev_err(dev, "error creating debugfs event files\n"); |
| } |
| |
| static int gpio_mockup_name_lines(struct device *dev, |
| struct gpio_mockup_chip *chip) |
| { |
| struct gpio_chip *gc = &chip->gc; |
| char **names; |
| int i; |
| |
| names = devm_kcalloc(dev, gc->ngpio, sizeof(char *), GFP_KERNEL); |
| if (!names) |
| return -ENOMEM; |
| |
| for (i = 0; i < gc->ngpio; i++) { |
| names[i] = devm_kasprintf(dev, GFP_KERNEL, |
| "%s-%d", gc->label, i); |
| if (!names[i]) |
| return -ENOMEM; |
| } |
| |
| gc->names = (const char *const *)names; |
| |
| return 0; |
| } |
| |
| static int gpio_mockup_probe(struct platform_device *pdev) |
| { |
| struct gpio_mockup_chip *chip; |
| struct gpio_chip *gc; |
| struct device *dev; |
| const char *name; |
| int rv, base; |
| u16 ngpio; |
| |
| dev = &pdev->dev; |
| |
| rv = device_property_read_u32(dev, "gpio-base", &base); |
| if (rv) |
| base = -1; |
| |
| rv = device_property_read_u16(dev, "nr-gpios", &ngpio); |
| if (rv) |
| return rv; |
| |
| rv = device_property_read_string(dev, "chip-name", &name); |
| if (rv) |
| name = NULL; |
| |
| chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); |
| if (!chip) |
| return -ENOMEM; |
| |
| if (!name) { |
| name = devm_kasprintf(dev, GFP_KERNEL, |
| "%s-%c", pdev->name, pdev->id + 'A'); |
| if (!name) |
| return -ENOMEM; |
| } |
| |
| gc = &chip->gc; |
| gc->base = base; |
| gc->ngpio = ngpio; |
| gc->label = name; |
| gc->owner = THIS_MODULE; |
| gc->parent = dev; |
| gc->get = gpio_mockup_get; |
| gc->set = gpio_mockup_set; |
| gc->set_multiple = gpio_mockup_set_multiple; |
| gc->direction_output = gpio_mockup_dirout; |
| gc->direction_input = gpio_mockup_dirin; |
| gc->get_direction = gpio_mockup_get_direction; |
| gc->to_irq = gpio_mockup_to_irq; |
| |
| chip->lines = devm_kcalloc(dev, gc->ngpio, |
| sizeof(*chip->lines), GFP_KERNEL); |
| if (!chip->lines) |
| return -ENOMEM; |
| |
| if (device_property_read_bool(dev, "named-gpio-lines")) { |
| rv = gpio_mockup_name_lines(dev, chip); |
| if (rv) |
| return rv; |
| } |
| |
| rv = devm_irq_sim_init(dev, &chip->irqsim, gc->ngpio); |
| if (rv < 0) |
| return rv; |
| |
| rv = devm_gpiochip_add_data(dev, &chip->gc, chip); |
| if (rv) |
| return rv; |
| |
| if (!IS_ERR_OR_NULL(gpio_mockup_dbg_dir)) |
| gpio_mockup_debugfs_setup(dev, chip); |
| |
| return 0; |
| } |
| |
| static struct platform_driver gpio_mockup_driver = { |
| .driver = { |
| .name = GPIO_MOCKUP_NAME, |
| }, |
| .probe = gpio_mockup_probe, |
| }; |
| |
| static struct platform_device *gpio_mockup_pdevs[GPIO_MOCKUP_MAX_GC]; |
| |
| static void gpio_mockup_unregister_pdevs(void) |
| { |
| struct platform_device *pdev; |
| int i; |
| |
| for (i = 0; i < GPIO_MOCKUP_MAX_GC; i++) { |
| pdev = gpio_mockup_pdevs[i]; |
| |
| if (pdev) |
| platform_device_unregister(pdev); |
| } |
| } |
| |
| static int __init gpio_mockup_init(void) |
| { |
| struct property_entry properties[GPIO_MOCKUP_MAX_PROP]; |
| int i, prop, num_chips, err = 0, base; |
| struct platform_device_info pdevinfo; |
| struct platform_device *pdev; |
| u16 ngpio; |
| |
| if ((gpio_mockup_num_ranges < 2) || |
| (gpio_mockup_num_ranges % 2) || |
| (gpio_mockup_num_ranges > GPIO_MOCKUP_MAX_RANGES)) |
| return -EINVAL; |
| |
| /* Each chip is described by two values. */ |
| num_chips = gpio_mockup_num_ranges / 2; |
| |
| /* |
| * The second value in the <base GPIO - number of GPIOS> pair must |
| * always be greater than 0. |
| */ |
| for (i = 0; i < num_chips; i++) { |
| if (gpio_mockup_range_ngpio(i) < 0) |
| return -EINVAL; |
| } |
| |
| gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL); |
| if (IS_ERR_OR_NULL(gpio_mockup_dbg_dir)) |
| gpio_mockup_err("error creating debugfs directory\n"); |
| |
| err = platform_driver_register(&gpio_mockup_driver); |
| if (err) { |
| gpio_mockup_err("error registering platform driver\n"); |
| return err; |
| } |
| |
| for (i = 0; i < num_chips; i++) { |
| memset(properties, 0, sizeof(properties)); |
| memset(&pdevinfo, 0, sizeof(pdevinfo)); |
| prop = 0; |
| |
| base = gpio_mockup_range_base(i); |
| if (base >= 0) |
| properties[prop++] = PROPERTY_ENTRY_U32("gpio-base", |
| base); |
| |
| ngpio = base < 0 ? gpio_mockup_range_ngpio(i) |
| : gpio_mockup_range_ngpio(i) - base; |
| properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio); |
| |
| if (gpio_mockup_named_lines) |
| properties[prop++] = PROPERTY_ENTRY_BOOL( |
| "named-gpio-lines"); |
| |
| pdevinfo.name = GPIO_MOCKUP_NAME; |
| pdevinfo.id = i; |
| pdevinfo.properties = properties; |
| |
| pdev = platform_device_register_full(&pdevinfo); |
| if (IS_ERR(pdev)) { |
| gpio_mockup_err("error registering device"); |
| platform_driver_unregister(&gpio_mockup_driver); |
| gpio_mockup_unregister_pdevs(); |
| return PTR_ERR(pdev); |
| } |
| |
| gpio_mockup_pdevs[i] = pdev; |
| } |
| |
| return 0; |
| } |
| |
| static void __exit gpio_mockup_exit(void) |
| { |
| debugfs_remove_recursive(gpio_mockup_dbg_dir); |
| platform_driver_unregister(&gpio_mockup_driver); |
| gpio_mockup_unregister_pdevs(); |
| } |
| |
| module_init(gpio_mockup_init); |
| module_exit(gpio_mockup_exit); |
| |
| MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>"); |
| MODULE_AUTHOR("Bamvor Jian Zhang <bamv2005@gmail.com>"); |
| MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>"); |
| MODULE_DESCRIPTION("GPIO Testing driver"); |
| MODULE_LICENSE("GPL v2"); |