From 9202ba2397d1ded79078606c6921787b27a85e1a Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 6 Feb 2017 15:11:08 +0100 Subject: [PATCH] gpio: mockup: implement event injecting over debugfs Create a debugfs directory for every mockup chip and a single file for every line. Writing (0 or 1) to these files allows the user to inject line events (falling or rising edge respectively). Signed-off-by: Bartosz Golaszewski Signed-off-by: Linus Walleij --- drivers/gpio/gpio-mockup.c | 116 ++++++++++++++++++++++++++++++++++++- 1 file changed, 115 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index 03beadb20dee..06dac72cb69c 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -14,11 +14,16 @@ #include #include #include +#include #include #include #include #include #include +#include +#include + +#include "gpiolib.h" #define GPIO_MOCKUP_NAME "gpio-mockup" #define GPIO_MOCKUP_MAX_GC 10 @@ -47,6 +52,13 @@ 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]; @@ -58,6 +70,7 @@ 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) { @@ -175,6 +188,94 @@ static int gpio_mockup_irqchip_setup(struct device *dev, 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) @@ -209,7 +310,14 @@ static int gpio_mockup_add(struct device *dev, if (ret) return ret; - return devm_gpiochip_add_data(dev, &chip->gc, chip); + 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) @@ -291,6 +399,11 @@ 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; @@ -312,6 +425,7 @@ static int __init mock_device_init(void) static void __exit mock_device_exit(void) { + debugfs_remove_recursive(gpio_mockup_dbg_dir); platform_driver_unregister(&gpio_mockup_driver); platform_device_unregister(pdev); }