From 50a212ec906f7524620675f0c57357691c26c81f Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Wed, 16 Oct 2024 01:20:19 +0000 Subject: [PATCH] 修改GPIO导出默认初始值 --- kernel/drivers/gpio/gpio-mockup.c | 461 +++++++++++++++++++++++++++++++++++++++++---------------- 1 files changed, 333 insertions(+), 128 deletions(-) diff --git a/kernel/drivers/gpio/gpio-mockup.c b/kernel/drivers/gpio/gpio-mockup.c index cab324e..e20b604 100644 --- a/kernel/drivers/gpio/gpio-mockup.c +++ b/kernel/drivers/gpio/gpio-mockup.c @@ -1,4 +1,4 @@ -// SPDX-License-Identifier: GPL-2.0+ +// SPDX-License-Identifier: GPL-2.0-or-later /* * GPIO Testing Device Driver * @@ -7,63 +7,55 @@ * Copyright (C) 2017 Bartosz Golaszewski <brgl@bgdev.pl> */ -#include <linux/init.h> -#include <linux/module.h> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/debugfs.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/irqdomain.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/slab.h> +#include <linux/string_helpers.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, -}; +/* Maximum of four properties + the sentinel. */ +#define GPIO_MOCKUP_MAX_PROP 5 /* * struct gpio_pin_status - structure describing a GPIO status - * @dir: Configures direction of gpio as "in" or "out", 0=in, 1=out + * @dir: Configures direction of gpio as "in" or "out" * @value: Configures status of the gpio as 0(low) or 1(high) */ struct gpio_mockup_line_status { int dir; int value; + int pull; }; struct gpio_mockup_chip { struct gpio_chip gc; struct gpio_mockup_line_status *lines; - struct irq_sim irqsim; + struct irq_domain *irq_sim_domain; struct dentry *dbg_dir; + struct mutex lock; }; 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; + unsigned int offset; }; static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_RANGES]; @@ -86,29 +78,133 @@ return gpio_mockup_ranges[index * 2 + 1]; } -static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset) +static int __gpio_mockup_get(struct gpio_mockup_chip *chip, + unsigned int offset) { - struct gpio_mockup_chip *chip = gpiochip_get_data(gc); - return chip->lines[offset].value; } +static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset) +{ + struct gpio_mockup_chip *chip = gpiochip_get_data(gc); + int val; + + mutex_lock(&chip->lock); + val = __gpio_mockup_get(chip, offset); + mutex_unlock(&chip->lock); + + return val; +} + +static int gpio_mockup_get_multiple(struct gpio_chip *gc, + unsigned long *mask, unsigned long *bits) +{ + struct gpio_mockup_chip *chip = gpiochip_get_data(gc); + unsigned int bit, val; + + mutex_lock(&chip->lock); + for_each_set_bit(bit, mask, gc->ngpio) { + val = __gpio_mockup_get(chip, bit); + __assign_bit(bit, bits, val); + } + mutex_unlock(&chip->lock); + + return 0; +} + +static void __gpio_mockup_set(struct gpio_mockup_chip *chip, + unsigned int offset, int value) +{ + chip->lines[offset].value = !!value; +} + static void gpio_mockup_set(struct gpio_chip *gc, - unsigned int offset, int value) + unsigned int offset, int value) { struct gpio_mockup_chip *chip = gpiochip_get_data(gc); - chip->lines[offset].value = !!value; + mutex_lock(&chip->lock); + __gpio_mockup_set(chip, offset, value); + mutex_unlock(&chip->lock); } static void gpio_mockup_set_multiple(struct gpio_chip *gc, unsigned long *mask, unsigned long *bits) { + struct gpio_mockup_chip *chip = gpiochip_get_data(gc); unsigned int bit; + mutex_lock(&chip->lock); for_each_set_bit(bit, mask, gc->ngpio) - gpio_mockup_set(gc, bit, test_bit(bit, bits)); + __gpio_mockup_set(chip, bit, test_bit(bit, bits)); + mutex_unlock(&chip->lock); +} +static int gpio_mockup_apply_pull(struct gpio_mockup_chip *chip, + unsigned int offset, int value) +{ + int curr, irq, irq_type, ret = 0; + struct gpio_desc *desc; + struct gpio_chip *gc; + + gc = &chip->gc; + desc = &gc->gpiodev->descs[offset]; + + mutex_lock(&chip->lock); + + if (test_bit(FLAG_REQUESTED, &desc->flags) && + !test_bit(FLAG_IS_OUT, &desc->flags)) { + curr = __gpio_mockup_get(chip, offset); + if (curr == value) + goto out; + + irq = irq_find_mapping(chip->irq_sim_domain, offset); + if (!irq) + /* + * This is fine - it just means, nobody is listening + * for interrupts on this line, otherwise + * irq_create_mapping() would have been called from + * the to_irq() callback. + */ + goto set_value; + + irq_type = irq_get_trigger_type(irq); + + if ((value == 1 && (irq_type & IRQ_TYPE_EDGE_RISING)) || + (value == 0 && (irq_type & IRQ_TYPE_EDGE_FALLING))) { + ret = irq_set_irqchip_state(irq, IRQCHIP_STATE_PENDING, + true); + if (ret) + goto out; + } + } + +set_value: + /* Change the value unless we're actively driving the line. */ + if (!test_bit(FLAG_REQUESTED, &desc->flags) || + !test_bit(FLAG_IS_OUT, &desc->flags)) + __gpio_mockup_set(chip, offset, value); + +out: + chip->lines[offset].pull = value; + mutex_unlock(&chip->lock); + return ret; +} + +static int gpio_mockup_set_config(struct gpio_chip *gc, + unsigned int offset, unsigned long config) +{ + struct gpio_mockup_chip *chip = gpiochip_get_data(gc); + + switch (pinconf_to_config_param(config)) { + case PIN_CONFIG_BIAS_PULL_UP: + return gpio_mockup_apply_pull(chip, offset, 1); + case PIN_CONFIG_BIAS_PULL_DOWN: + return gpio_mockup_apply_pull(chip, offset, 0); + default: + break; + } + return -ENOTSUPP; } static int gpio_mockup_dirout(struct gpio_chip *gc, @@ -116,8 +212,10 @@ { struct gpio_mockup_chip *chip = gpiochip_get_data(gc); - gpio_mockup_set(gc, offset, value); - chip->lines[offset].dir = GPIO_MOCKUP_DIR_OUT; + mutex_lock(&chip->lock); + chip->lines[offset].dir = GPIO_LINE_DIRECTION_OUT; + __gpio_mockup_set(chip, offset, value); + mutex_unlock(&chip->lock); return 0; } @@ -126,7 +224,9 @@ { struct gpio_mockup_chip *chip = gpiochip_get_data(gc); - chip->lines[offset].dir = GPIO_MOCKUP_DIR_IN; + mutex_lock(&chip->lock); + chip->lines[offset].dir = GPIO_LINE_DIRECTION_IN; + mutex_unlock(&chip->lock); return 0; } @@ -134,26 +234,64 @@ static int gpio_mockup_get_direction(struct gpio_chip *gc, unsigned int offset) { struct gpio_mockup_chip *chip = gpiochip_get_data(gc); + int direction; - return !chip->lines[offset].dir; + mutex_lock(&chip->lock); + direction = chip->lines[offset].dir; + mutex_unlock(&chip->lock); + + return direction; } 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); + return irq_create_mapping(chip->irq_sim_domain, offset); } -static ssize_t gpio_mockup_event_write(struct file *file, - const char __user *usr_buf, - size_t size, loff_t *ppos) +static void gpio_mockup_free(struct gpio_chip *gc, unsigned int offset) +{ + struct gpio_mockup_chip *chip = gpiochip_get_data(gc); + + __gpio_mockup_set(chip, offset, chip->lines[offset].pull); +} + +static ssize_t gpio_mockup_debugfs_read(struct file *file, + 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 val, cnt; + char buf[3]; + + if (*ppos != 0) + return 0; + + sfile = file->private_data; + priv = sfile->private; + chip = priv->chip; + gc = &chip->gc; + + val = gpio_mockup_get(gc, priv->offset); + cnt = snprintf(buf, sizeof(buf), "%d\n", val); + + return simple_read_from_buffer(usr_buf, size, ppos, buf, cnt); +} + +static ssize_t gpio_mockup_debugfs_write(struct file *file, + const char __user *usr_buf, + size_t size, loff_t *ppos) +{ + struct gpio_mockup_dbgfs_private *priv; int rv, val; + struct seq_file *sfile; + + if (*ppos != 0) + return -EINVAL; rv = kstrtoint_from_user(usr_buf, size, 0, &val); if (rv) @@ -163,32 +301,52 @@ 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); + rv = gpio_mockup_apply_pull(priv->chip, priv->offset, val); + if (rv) + return rv; return size; } -static int gpio_mockup_event_open(struct inode *inode, struct file *file) +static int gpio_mockup_debugfs_open(struct inode *inode, struct file *file) { return single_open(file, NULL, inode->i_private); } -static const struct file_operations gpio_mockup_event_ops = { +/* + * Each mockup chip is represented by a directory named after the chip's device + * name under /sys/kernel/debug/gpio-mockup/. Each line is represented by + * a file using the line's offset as the name under the chip's directory. + * + * Reading from the line's file yields the current *value*, writing to the + * line's file changes the current *pull*. Default pull for mockup lines is + * down. + * + * Examples: + * - when a line pulled down is requested in output mode and driven high, its + * value will return to 0 once it's released + * - when the line is requested in output mode and driven high, writing 0 to + * the corresponding debugfs file will change the pull to down but the + * reported value will still be 1 until the line is released + * - line requested in input mode always reports the same value as its pull + * configuration + * - when the line is requested in input mode and monitored for events, writing + * the same value to the debugfs file will be a noop, while writing the + * opposite value will generate a dummy interrupt with an appropriate edge + */ +static const struct file_operations gpio_mockup_debugfs_ops = { .owner = THIS_MODULE, - .open = gpio_mockup_event_open, - .write = gpio_mockup_event_write, + .open = gpio_mockup_debugfs_open, + .read = gpio_mockup_debugfs_read, + .write = gpio_mockup_debugfs_write, .llseek = no_llseek, + .release = single_release, }; 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; @@ -198,83 +356,73 @@ 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; + return; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) - goto err; + return; 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; + debugfs_create_file(name, 0600, chip->dbg_dir, priv, + &gpio_mockup_debugfs_ops); } - - 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) +static void gpio_mockup_debugfs_cleanup(void *data) { - struct gpio_chip *gc = &chip->gc; - char **names; - int i; + struct gpio_mockup_chip *chip = data; - names = devm_kcalloc(dev, gc->ngpio, sizeof(char *), GFP_KERNEL); - if (!names) - return -ENOMEM; + debugfs_remove_recursive(chip->dbg_dir); +} + +static void gpio_mockup_dispose_mappings(void *data) +{ + struct gpio_mockup_chip *chip = data; + struct gpio_chip *gc = &chip->gc; + int i, irq; for (i = 0; i < gc->ngpio; i++) { - names[i] = devm_kasprintf(dev, GFP_KERNEL, - "%s-%d", gc->label, i); - if (!names[i]) - return -ENOMEM; + irq = irq_find_mapping(chip->irq_sim_domain, i); + if (irq) + irq_dispose_mapping(irq); } - - 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; + const char *name; + int rv, base, i; + u16 ngpio; dev = &pdev->dev; - pdata = dev_get_platdata(dev); - base = pdata->base; - ngpio = pdata->ngpio; + + 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-label", &name); + if (rv) + name = dev_name(dev); 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; + mutex_init(&chip->lock); gc = &chip->gc; gc->base = base; @@ -284,40 +432,44 @@ gc->parent = dev; gc->get = gpio_mockup_get; gc->set = gpio_mockup_set; + gc->get_multiple = gpio_mockup_get_multiple; 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->set_config = gpio_mockup_set_config; gc->to_irq = gpio_mockup_to_irq; + gc->free = gpio_mockup_free; 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; - } + for (i = 0; i < gc->ngpio; i++) + chip->lines[i].dir = GPIO_LINE_DIRECTION_IN; - rv = devm_irq_sim_init(dev, &chip->irqsim, gc->ngpio); - if (rv < 0) + chip->irq_sim_domain = devm_irq_domain_create_sim(dev, NULL, + gc->ngpio); + if (IS_ERR(chip->irq_sim_domain)) + return PTR_ERR(chip->irq_sim_domain); + + rv = devm_add_action_or_reset(dev, gpio_mockup_dispose_mappings, chip); + if (rv) 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); + gpio_mockup_debugfs_setup(dev, chip); - return 0; + return devm_add_action_or_reset(dev, gpio_mockup_debugfs_cleanup, chip); } static struct platform_driver gpio_mockup_driver = { .driver = { - .name = GPIO_MOCKUP_NAME, + .name = "gpio-mockup", }, .probe = gpio_mockup_probe, }; @@ -337,11 +489,79 @@ } } +static __init char **gpio_mockup_make_line_names(const char *label, + unsigned int num_lines) +{ + unsigned int i; + char **names; + + names = kcalloc(num_lines + 1, sizeof(char *), GFP_KERNEL); + if (!names) + return NULL; + + for (i = 0; i < num_lines; i++) { + names[i] = kasprintf(GFP_KERNEL, "%s-%u", label, i); + if (!names[i]) { + kfree_strarray(names, i); + return NULL; + } + } + + return names; +} + +static int __init gpio_mockup_register_chip(int idx) +{ + struct property_entry properties[GPIO_MOCKUP_MAX_PROP]; + struct platform_device_info pdevinfo; + struct platform_device *pdev; + char **line_names = NULL; + char chip_label[32]; + int prop = 0, base; + u16 ngpio; + + memset(properties, 0, sizeof(properties)); + memset(&pdevinfo, 0, sizeof(pdevinfo)); + + snprintf(chip_label, sizeof(chip_label), "gpio-mockup-%c", idx + 'A'); + properties[prop++] = PROPERTY_ENTRY_STRING("chip-label", chip_label); + + base = gpio_mockup_range_base(idx); + if (base >= 0) + properties[prop++] = PROPERTY_ENTRY_U32("gpio-base", base); + + ngpio = base < 0 ? gpio_mockup_range_ngpio(idx) + : gpio_mockup_range_ngpio(idx) - base; + properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio); + + if (gpio_mockup_named_lines) { + line_names = gpio_mockup_make_line_names(chip_label, ngpio); + if (!line_names) + return -ENOMEM; + + properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( + "gpio-line-names", line_names, ngpio); + } + + pdevinfo.name = "gpio-mockup"; + pdevinfo.id = idx; + pdevinfo.properties = properties; + + pdev = platform_device_register_full(&pdevinfo); + kfree_strarray(line_names, ngpio); + if (IS_ERR(pdev)) { + pr_err("error registering device"); + return PTR_ERR(pdev); + } + + gpio_mockup_pdevs[idx] = pdev; + + return 0; +} + 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; + int i, num_chips, err; if ((gpio_mockup_num_ranges < 2) || (gpio_mockup_num_ranges % 2) || @@ -360,38 +580,23 @@ 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"); + gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup", NULL); err = platform_driver_register(&gpio_mockup_driver); if (err) { - gpio_mockup_err("error registering platform driver\n"); + pr_err("error registering platform driver\n"); debugfs_remove_recursive(gpio_mockup_dbg_dir); 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"); + err = gpio_mockup_register_chip(i); + if (err) { platform_driver_unregister(&gpio_mockup_driver); gpio_mockup_unregister_pdevs(); debugfs_remove_recursive(gpio_mockup_dbg_dir); - return PTR_ERR(pdev); + return err; } - - gpio_mockup_pdevs[i] = pdev; } return 0; @@ -399,9 +604,9 @@ static void __exit gpio_mockup_exit(void) { + gpio_mockup_unregister_pdevs(); debugfs_remove_recursive(gpio_mockup_dbg_dir); platform_driver_unregister(&gpio_mockup_driver); - gpio_mockup_unregister_pdevs(); } module_init(gpio_mockup_init); -- Gitblit v1.6.2