| /* |
| * GPIO Testing Device Driver |
| * |
| * Copyright (C) 2014 Kamlakant Patel <kamlakant.patel@broadcom.com> |
| * Copyright (C) 2015-2016 Bamvor Jian Zhang <bamvor.zhangjian@linaro.org> |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License as published by the |
| * Free Software Foundation; either version 2 of the License, or (at your |
| * option) any later version. |
| * |
| */ |
| |
| #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_work.h> |
| #include <linux/debugfs.h> |
| #include <linux/uaccess.h> |
| |
| #include "gpiolib.h" |
| |
| #define GPIO_MOCKUP_NAME "gpio-mockup" |
| #define GPIO_MOCKUP_MAX_GC 10 |
| |
| enum { |
| DIR_IN = 0, |
| DIR_OUT, |
| }; |
| |
| /* |
| * 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; |
| bool value; |
| }; |
| |
| struct gpio_mockup_irq_context { |
| struct irq_work work; |
| int irq; |
| }; |
| |
| struct gpio_mockup_chip { |
| struct gpio_chip gc; |
| struct gpio_mockup_line_status *lines; |
| struct gpio_mockup_irq_context irq_ctx; |
| 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_GC << 1]; |
| static int gpio_mockup_params_nr; |
| module_param_array(gpio_mockup_ranges, int, &gpio_mockup_params_nr, 0400); |
| |
| static bool gpio_mockup_named_lines; |
| module_param_named(gpio_mockup_named_lines, |
| gpio_mockup_named_lines, bool, 0400); |
| |
| static const char gpio_mockup_name_start = 'A'; |
| static struct dentry *gpio_mockup_dbg_dir; |
| |
| 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 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 = 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 = 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_name_lines(struct device *dev, |
| struct gpio_mockup_chip *chip) |
| { |
| struct gpio_chip *gc = &chip->gc; |
| char **names; |
| int i; |
| |
| names = devm_kzalloc(dev, sizeof(char *) * gc->ngpio, 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_to_irq(struct gpio_chip *chip, unsigned int offset) |
| { |
| return chip->irq_base + offset; |
| } |
| |
| /* |
| * While we should generally support irqmask and irqunmask, this driver is |
| * for testing purposes only so we don't care. |
| */ |
| static void gpio_mockup_irqmask(struct irq_data *d) { } |
| static void gpio_mockup_irqunmask(struct irq_data *d) { } |
| |
| static struct irq_chip gpio_mockup_irqchip = { |
| .name = GPIO_MOCKUP_NAME, |
| .irq_mask = gpio_mockup_irqmask, |
| .irq_unmask = gpio_mockup_irqunmask, |
| }; |
| |
| static void gpio_mockup_handle_irq(struct irq_work *work) |
| { |
| struct gpio_mockup_irq_context *irq_ctx; |
| |
| irq_ctx = container_of(work, struct gpio_mockup_irq_context, work); |
| handle_simple_irq(irq_to_desc(irq_ctx->irq)); |
| } |
| |
| static int gpio_mockup_irqchip_setup(struct device *dev, |
| struct gpio_mockup_chip *chip) |
| { |
| struct gpio_chip *gc = &chip->gc; |
| int irq_base, i; |
| |
| irq_base = irq_alloc_descs(-1, 0, gc->ngpio, 0); |
| if (irq_base < 0) |
| return irq_base; |
| |
| gc->irq_base = irq_base; |
| gc->irqchip = &gpio_mockup_irqchip; |
| |
| for (i = 0; i < gc->ngpio; i++) { |
| irq_set_chip(irq_base + i, gc->irqchip); |
| irq_set_handler(irq_base + i, &handle_simple_irq); |
| irq_modify_status(irq_base + i, |
| IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE); |
| } |
| |
| init_irq_work(&chip->irq_ctx.work, gpio_mockup_handle_irq); |
| |
| return 0; |
| } |
| |
| 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; |
| struct gpio_chip *gc; |
| int status, val; |
| char buf; |
| |
| sfile = file->private_data; |
| priv = sfile->private; |
| desc = priv->desc; |
| chip = priv->chip; |
| gc = &chip->gc; |
| |
| status = copy_from_user(&buf, usr_buf, 1); |
| if (status) |
| return status; |
| |
| if (buf == '0') |
| val = 0; |
| else if (buf == '1') |
| val = 1; |
| else |
| return -EINVAL; |
| |
| gpiod_set_value_cansleep(desc, val); |
| priv->chip->irq_ctx.irq = gc->irq_base + priv->offset; |
| irq_work_queue(&priv->chip->irq_ctx.work); |
| |
| 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; |
| struct gpio_chip *gc; |
| char *name; |
| int i; |
| |
| gc = &chip->gc; |
| |
| chip->dbg_dir = debugfs_create_dir(gc->label, gpio_mockup_dbg_dir); |
| if (!chip->dbg_dir) |
| 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 (!evfile) |
| goto err; |
| } |
| |
| return; |
| |
| err: |
| dev_err(dev, "error creating debugfs directory\n"); |
| } |
| |
| static int gpio_mockup_add(struct device *dev, |
| struct gpio_mockup_chip *chip, |
| const char *name, int base, int ngpio) |
| { |
| struct gpio_chip *gc = &chip->gc; |
| int ret; |
| |
| 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->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_kzalloc(dev, sizeof(*chip->lines) * gc->ngpio, |
| GFP_KERNEL); |
| if (!chip->lines) |
| return -ENOMEM; |
| |
| if (gpio_mockup_named_lines) { |
| ret = gpio_mockup_name_lines(dev, chip); |
| if (ret) |
| return ret; |
| } |
| |
| ret = gpio_mockup_irqchip_setup(dev, chip); |
| if (ret) |
| return ret; |
| |
| ret = devm_gpiochip_add_data(dev, &chip->gc, chip); |
| if (ret) |
| return ret; |
| |
| if (gpio_mockup_dbg_dir) |
| gpio_mockup_debugfs_setup(dev, chip); |
| |
| return 0; |
| } |
| |
| static int gpio_mockup_probe(struct platform_device *pdev) |
| { |
| struct gpio_mockup_chip *chips; |
| struct device *dev = &pdev->dev; |
| int ret, i, base, ngpio; |
| char *chip_name; |
| |
| if (gpio_mockup_params_nr < 2) |
| return -EINVAL; |
| |
| chips = devm_kzalloc(dev, |
| sizeof(*chips) * (gpio_mockup_params_nr >> 1), |
| GFP_KERNEL); |
| if (!chips) |
| return -ENOMEM; |
| |
| platform_set_drvdata(pdev, chips); |
| |
| for (i = 0; i < gpio_mockup_params_nr >> 1; i++) { |
| base = gpio_mockup_ranges[i * 2]; |
| |
| if (base == -1) |
| ngpio = gpio_mockup_ranges[i * 2 + 1]; |
| else |
| ngpio = gpio_mockup_ranges[i * 2 + 1] - base; |
| |
| if (ngpio >= 0) { |
| chip_name = devm_kasprintf(dev, GFP_KERNEL, |
| "%s-%c", GPIO_MOCKUP_NAME, |
| gpio_mockup_name_start + i); |
| if (!chip_name) |
| return -ENOMEM; |
| |
| ret = gpio_mockup_add(dev, &chips[i], |
| chip_name, base, ngpio); |
| } else { |
| ret = -1; |
| } |
| |
| if (ret) { |
| dev_err(dev, "gpio<%d..%d> add failed\n", |
| base, base < 0 ? ngpio : base + ngpio); |
| |
| return ret; |
| } |
| |
| dev_info(dev, "gpio<%d..%d> add successful!", |
| base, base + ngpio); |
| } |
| |
| return 0; |
| } |
| |
| static int gpio_mockup_remove(struct platform_device *pdev) |
| { |
| struct gpio_mockup_chip *chips; |
| int i; |
| |
| chips = platform_get_drvdata(pdev); |
| |
| for (i = 0; i < gpio_mockup_params_nr >> 1; i++) |
| irq_free_descs(chips[i].gc.irq_base, chips[i].gc.ngpio); |
| |
| return 0; |
| } |
| |
| static struct platform_driver gpio_mockup_driver = { |
| .driver = { |
| .name = GPIO_MOCKUP_NAME, |
| }, |
| .probe = gpio_mockup_probe, |
| .remove = gpio_mockup_remove, |
| }; |
| |
| static struct platform_device *pdev; |
| static int __init mock_device_init(void) |
| { |
| int err; |
| |
| gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL); |
| if (!gpio_mockup_dbg_dir) |
| pr_err("%s: error creating debugfs directory\n", |
| GPIO_MOCKUP_NAME); |
| |
| pdev = platform_device_alloc(GPIO_MOCKUP_NAME, -1); |
| if (!pdev) |
| return -ENOMEM; |
| |
| err = platform_device_add(pdev); |
| if (err) { |
| platform_device_put(pdev); |
| return err; |
| } |
| |
| err = platform_driver_register(&gpio_mockup_driver); |
| if (err) { |
| platform_device_unregister(pdev); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| static void __exit mock_device_exit(void) |
| { |
| debugfs_remove_recursive(gpio_mockup_dbg_dir); |
| platform_driver_unregister(&gpio_mockup_driver); |
| platform_device_unregister(pdev); |
| } |
| |
| module_init(mock_device_init); |
| module_exit(mock_device_exit); |
| |
| MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>"); |
| MODULE_AUTHOR("Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>"); |
| MODULE_DESCRIPTION("GPIO Testing driver"); |
| MODULE_LICENSE("GPL v2"); |