|  | // 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 "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) | 
|  |  | 
|  | #define gpio_mockup_err(...)	pr_err(GPIO_MOCKUP_NAME ": " __VA_ARGS__) | 
|  |  | 
|  | enum { | 
|  | GPIO_MOCKUP_DIR_IN = 0, | 
|  | GPIO_MOCKUP_DIR_OUT = 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; | 
|  | }; | 
|  |  | 
|  | struct gpio_mockup_platform_data { | 
|  | int base; | 
|  | int ngpio; | 
|  | int index; | 
|  | bool named_lines; | 
|  | }; | 
|  |  | 
|  | 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_platform_data *pdata; | 
|  | struct gpio_mockup_chip *chip; | 
|  | struct gpio_chip *gc; | 
|  | int rv, base, ngpio; | 
|  | struct device *dev; | 
|  | char *name; | 
|  |  | 
|  | dev = &pdev->dev; | 
|  | pdata = dev_get_platdata(dev); | 
|  | base = pdata->base; | 
|  | ngpio = pdata->ngpio; | 
|  |  | 
|  | chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); | 
|  | if (!chip) | 
|  | return -ENOMEM; | 
|  |  | 
|  | name = devm_kasprintf(dev, GFP_KERNEL, "%s-%c", | 
|  | pdev->name, pdata->index); | 
|  | 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 (pdata->named_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) | 
|  | { | 
|  | int i, num_chips, err = 0, index = 'A'; | 
|  | struct gpio_mockup_platform_data pdata; | 
|  | struct platform_device *pdev; | 
|  |  | 
|  | 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++) { | 
|  | pdata.index = index++; | 
|  | pdata.base = gpio_mockup_range_base(i); | 
|  | pdata.ngpio = pdata.base < 0 | 
|  | ? gpio_mockup_range_ngpio(i) | 
|  | : gpio_mockup_range_ngpio(i) - pdata.base; | 
|  | pdata.named_lines = gpio_mockup_named_lines; | 
|  |  | 
|  | pdev = platform_device_register_resndata(NULL, | 
|  | GPIO_MOCKUP_NAME, | 
|  | i, NULL, 0, &pdata, | 
|  | sizeof(pdata)); | 
|  | 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"); |