diff options
| -rw-r--r-- | drivers/gpio/gpiolib-sysfs.c | 12 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib.c | 232 | ||||
| -rw-r--r-- | drivers/gpio/gpiolib.h | 27 | ||||
| -rw-r--r-- | include/linux/gpio/driver.h | 7 |
4 files changed, 201 insertions, 77 deletions
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index 405dfcaadc4c..28d3bf2328aa 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -547,6 +547,7 @@ static struct class gpio_class = { int gpiod_export(struct gpio_desc *desc, bool direction_may_change) { struct gpio_chip *chip; + struct gpio_device *gdev; struct gpiod_data *data; unsigned long flags; int status; @@ -566,6 +567,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change) } chip = desc->chip; + gdev = chip->gpiodev; mutex_lock(&sysfs_lock); @@ -605,7 +607,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change) if (chip->names && chip->names[offset]) ioname = chip->names[offset]; - dev = device_create_with_groups(&gpio_class, chip->parent, + dev = device_create_with_groups(&gpio_class, &gdev->dev, MKDEV(0, 0), data, gpio_groups, ioname ? ioname : "gpio%u", desc_to_gpio(desc)); @@ -771,7 +773,7 @@ static int __init gpiolib_sysfs_init(void) { int status; unsigned long flags; - struct gpio_chip *chip; + struct gpio_device *gdev; status = class_register(&gpio_class); if (status < 0) @@ -784,8 +786,8 @@ static int __init gpiolib_sysfs_init(void) * registered, and so arch_initcall() can always gpio_export(). */ spin_lock_irqsave(&gpio_lock, flags); - list_for_each_entry(chip, &gpio_chips, list) { - if (chip->cdev) + list_for_each_entry(gdev, &gpio_devices, list) { + if (gdev->chip->cdev) continue; /* @@ -798,7 +800,7 @@ static int __init gpiolib_sysfs_init(void) * gpio_lock prevents us from doing this. */ spin_unlock_irqrestore(&gpio_lock, flags); - status = gpiochip_sysfs_register(chip); + status = gpiochip_sysfs_register(gdev->chip); spin_lock_irqsave(&gpio_lock, flags); } spin_unlock_irqrestore(&gpio_lock, flags); diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 5c1ba879f889..3a073ab5e863 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -16,6 +16,7 @@ #include <linux/gpio/driver.h> #include <linux/gpio/machine.h> #include <linux/pinctrl/consumer.h> +#include <linux/idr.h> #include "gpiolib.h" @@ -42,6 +43,9 @@ #define extra_checks 0 #endif +/* Device and char device-related information */ +static DEFINE_IDA(gpio_ida); + /* gpio_lock prevents conflicts during gpio_desc[] table updates. * While any GPIO is requested, its gpio_chip is not removable; * each GPIO's "requested" flag serves as a lock and refcount. @@ -50,8 +54,7 @@ DEFINE_SPINLOCK(gpio_lock); static DEFINE_MUTEX(gpio_lookup_lock); static LIST_HEAD(gpio_lookup_list); -LIST_HEAD(gpio_chips); - +LIST_HEAD(gpio_devices); static void gpiochip_free_hogs(struct gpio_chip *chip); static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip); @@ -67,15 +70,16 @@ static inline void desc_set_label(struct gpio_desc *d, const char *label) */ struct gpio_desc *gpio_to_desc(unsigned gpio) { - struct gpio_chip *chip; + struct gpio_device *gdev; unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); - list_for_each_entry(chip, &gpio_chips, list) { - if (chip->base <= gpio && chip->base + chip->ngpio > gpio) { + list_for_each_entry(gdev, &gpio_devices, list) { + if (gdev->chip->base <= gpio && + gdev->chip->base + gdev->chip->ngpio > gpio) { spin_unlock_irqrestore(&gpio_lock, flags); - return &chip->desc[gpio - chip->base]; + return &gdev->chip->desc[gpio - gdev->chip->base]; } } @@ -125,16 +129,16 @@ EXPORT_SYMBOL_GPL(gpiod_to_chip); /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ static int gpiochip_find_base(int ngpio) { - struct gpio_chip *chip; + struct gpio_device *gdev; int base = ARCH_NR_GPIOS - ngpio; - list_for_each_entry_reverse(chip, &gpio_chips, list) { + list_for_each_entry_reverse(gdev, &gpio_devices, list) { /* found a free space? */ - if (chip->base + chip->ngpio <= base) + if (gdev->chip->base + gdev->chip->ngpio <= base) break; else /* nope, check the space right before the chip */ - base = chip->base - ngpio; + base = gdev->chip->base - ngpio; } if (gpio_is_valid(base)) { @@ -187,18 +191,28 @@ EXPORT_SYMBOL_GPL(gpiod_get_direction); * Return -EBUSY if the new chip overlaps with some other chip's integer * space. */ -static int gpiochip_add_to_list(struct gpio_chip *chip) +static int gpiodev_add_to_list(struct gpio_device *gdev) { - struct gpio_chip *iterator; - struct gpio_chip *previous = NULL; + struct gpio_device *iterator; + struct gpio_device *previous = NULL; + + if (!gdev->chip) + return -EINVAL; - if (list_empty(&gpio_chips)) { - list_add_tail(&chip->list, &gpio_chips); + if (list_empty(&gpio_devices)) { + list_add_tail(&gdev->list, &gpio_devices); return 0; } - list_for_each_entry(iterator, &gpio_chips, list) { - if (iterator->base >= chip->base + chip->ngpio) { + list_for_each_entry(iterator, &gpio_devices, list) { + /* + * The list may contain dangling GPIO devices with no + * live chip assigned. + */ + if (!iterator->chip) + continue; + if (iterator->chip->base >= + gdev->chip->base + gdev->chip->ngpio) { /* * Iterator is the first GPIO chip so there is no * previous one @@ -211,8 +225,8 @@ static int gpiochip_add_to_list(struct gpio_chip *chip) * [base, base + ngpio - 1]) between previous * and iterator chip. */ - if (previous->base + previous->ngpio - <= chip->base) + if (previous->chip->base + previous->chip->ngpio + <= gdev->chip->base) goto found; } } @@ -225,18 +239,18 @@ static int gpiochip_add_to_list(struct gpio_chip *chip) * Let iterator point to the last chip in the list. */ - iterator = list_last_entry(&gpio_chips, struct gpio_chip, list); - if (iterator->base + iterator->ngpio <= chip->base) { - list_add(&chip->list, &iterator->list); + iterator = list_last_entry(&gpio_devices, struct gpio_device, list); + if (iterator->chip->base + iterator->chip->ngpio <= gdev->chip->base) { + list_add(&gdev->list, &iterator->list); return 0; } - dev_err(chip->parent, + dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n"); return -EBUSY; found: - list_add_tail(&chip->list, &iterator->list); + list_add_tail(&gdev->list, &iterator->list); return 0; } @@ -245,16 +259,16 @@ found: */ static struct gpio_desc *gpio_name_to_desc(const char * const name) { - struct gpio_chip *chip; + struct gpio_device *gdev; unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); - list_for_each_entry(chip, &gpio_chips, list) { + list_for_each_entry(gdev, &gpio_devices, list) { int i; - for (i = 0; i != chip->ngpio; ++i) { - struct gpio_desc *gpio = &chip->desc[i]; + for (i = 0; i != gdev->chip->ngpio; ++i) { + struct gpio_desc *gpio = &gdev->chip->desc[i]; if (!gpio->name || !name) continue; @@ -302,6 +316,14 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc) return 0; } +static void gpiodevice_release(struct device *dev) +{ + struct gpio_device *gdev = dev_get_drvdata(dev); + + list_del(&gdev->list); + ida_simple_remove(&gpio_ida, gdev->id); +} + /** * gpiochip_add_data() - register a gpio_chip * @chip: the chip to register, with chip->base initialized @@ -323,19 +345,60 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data) { unsigned long flags; int status = 0; - unsigned id; + unsigned i; int base = chip->base; struct gpio_desc *descs; + struct gpio_device *gdev; - descs = kcalloc(chip->ngpio, sizeof(descs[0]), GFP_KERNEL); - if (!descs) + /* + * First: allocate and populate the internal stat container, and + * set up the struct device. + */ + gdev = kmalloc(sizeof(*gdev), GFP_KERNEL); + if (!gdev) return -ENOMEM; + gdev->chip = chip; + chip->gpiodev = gdev; + if (chip->parent) { + gdev->dev.parent = chip->parent; + gdev->dev.of_node = chip->parent->of_node; + } else { +#ifdef CONFIG_OF_GPIO + /* If the gpiochip has an assigned OF node this takes precedence */ + if (chip->of_node) + gdev->dev.of_node = chip->of_node; +#endif + } + gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL); + if (gdev->id < 0) { + status = gdev->id; + goto err_free_gdev; + } + dev_set_name(&gdev->dev, "gpiochip%d", gdev->id); + device_initialize(&gdev->dev); + dev_set_drvdata(&gdev->dev, gdev); + if (chip->parent && chip->parent->driver) + gdev->owner = chip->parent->driver->owner; + else if (chip->owner) + /* TODO: remove chip->owner */ + gdev->owner = chip->owner; + else + gdev->owner = THIS_MODULE; + /* FIXME: devm_kcalloc() these and move to gpio_device */ + descs = kcalloc(chip->ngpio, sizeof(descs[0]), GFP_KERNEL); + if (!descs) { + status = -ENOMEM; + goto err_free_gdev; + } + + /* FIXME: move driver data into gpio_device dev_set_drvdata() */ chip->data = data; if (chip->ngpio == 0) { chip_err(chip, "tried to insert a GPIO chip with zero lines\n"); - return -EINVAL; + status = -EINVAL; + goto err_free_descs; } spin_lock_irqsave(&gpio_lock, flags); @@ -350,15 +413,16 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data) chip->base = base; } - status = gpiochip_add_to_list(chip); + status = gpiodev_add_to_list(gdev); if (status) { spin_unlock_irqrestore(&gpio_lock, flags); goto err_free_descs; } - for (id = 0; id < chip->ngpio; id++) { - struct gpio_desc *desc = &descs[id]; + for (i = 0; i < chip->ngpio; i++) { + struct gpio_desc *desc = &descs[i]; + /* REVISIT: maybe a pointer to gpio_device is better */ desc->chip = chip; /* REVISIT: most hardware initializes GPIOs as inputs (often @@ -369,18 +433,15 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data) */ desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0; } - chip->desc = descs; spin_unlock_irqrestore(&gpio_lock, flags); #ifdef CONFIG_PINCTRL + /* FIXME: move pin ranges to gpio_device */ INIT_LIST_HEAD(&chip->pin_ranges); #endif - if (!chip->owner && chip->parent && chip->parent->driver) - chip->owner = chip->parent->driver->owner; - status = gpiochip_set_desc_names(chip); if (status) goto err_remove_from_list; @@ -391,28 +452,39 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data) acpi_gpiochip_add(chip); - status = gpiochip_sysfs_register(chip); + status = device_add(&gdev->dev); if (status) goto err_remove_chip; + status = gpiochip_sysfs_register(chip); + if (status) + goto err_remove_device; + + /* From this point, the .release() function cleans up gpio_device */ + gdev->dev.release = gpiodevice_release; + get_device(&gdev->dev); pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__, chip->base, chip->base + chip->ngpio - 1, chip->label ? : "generic"); return 0; +err_remove_device: + device_del(&gdev->dev); err_remove_chip: acpi_gpiochip_remove(chip); gpiochip_free_hogs(chip); of_gpiochip_remove(chip); err_remove_from_list: spin_lock_irqsave(&gpio_lock, flags); - list_del(&chip->list); + list_del(&gdev->list); spin_unlock_irqrestore(&gpio_lock, flags); chip->desc = NULL; err_free_descs: kfree(descs); - +err_free_gdev: + ida_simple_remove(&gpio_ida, gdev->id); + kfree(gdev); /* failures here can mean systems won't boot... */ pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__, chip->base, chip->base + chip->ngpio - 1, @@ -429,15 +501,18 @@ EXPORT_SYMBOL_GPL(gpiochip_add_data); */ void gpiochip_remove(struct gpio_chip *chip) { + struct gpio_device *gdev = chip->gpiodev; struct gpio_desc *desc; unsigned long flags; unsigned id; bool requested = false; - gpiochip_sysfs_unregister(chip); + /* Numb the device, cancelling all outstanding operations */ + gdev->chip = NULL; + /* FIXME: should the legacy sysfs handling be moved to gpio_device? */ + gpiochip_sysfs_unregister(chip); gpiochip_irqchip_remove(chip); - acpi_gpiochip_remove(chip); gpiochip_remove_pin_ranges(chip); gpiochip_free_hogs(chip); @@ -450,15 +525,23 @@ void gpiochip_remove(struct gpio_chip *chip) if (test_bit(FLAG_REQUESTED, &desc->flags)) requested = true; } - list_del(&chip->list); spin_unlock_irqrestore(&gpio_lock, flags); if (requested) dev_crit(chip->parent, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n"); + /* FIXME: need to be moved to gpio_device and held there */ kfree(chip->desc); chip->desc = NULL; + + /* + * The gpiochip side puts its use of the device to rest here: + * if there are no userspace clients, the chardev and device will + * be removed, else it will be dangling until the last user is + * gone. + */ + put_device(&gdev->dev); } EXPORT_SYMBOL_GPL(gpiochip_remove); @@ -477,17 +560,21 @@ struct gpio_chip *gpiochip_find(void *data, int (*match)(struct gpio_chip *chip, void *data)) { + struct gpio_device *gdev; struct gpio_chip *chip; unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); - list_for_each_entry(chip, &gpio_chips, list) - if (match(chip, data)) + list_for_each_entry(gdev, &gpio_devices, list) + if (match(gdev->chip, data)) break; /* No match? */ - if (&chip->list == &gpio_chips) + if (&gdev->list == &gpio_devices) chip = NULL; + else + chip = gdev->chip; + spin_unlock_irqrestore(&gpio_lock, flags); return chip; @@ -617,14 +704,14 @@ static int gpiochip_irq_reqres(struct irq_data *d) { struct gpio_chip *chip = irq_data_get_irq_chip_data(d); - if (!try_module_get(chip->owner)) + if (!try_module_get(chip->gpiodev->owner)) return -ENODEV; if (gpiochip_lock_as_irq(chip, d->hwirq)) { chip_err(chip, "unable to lock HW IRQ %lu for IRQ\n", d->hwirq); - module_put(chip->owner); + module_put(chip->gpiodev->owner); return -EINVAL; } return 0; @@ -635,7 +722,7 @@ static void gpiochip_irq_relres(struct irq_data *d) struct gpio_chip *chip = irq_data_get_irq_chip_data(d); gpiochip_unlock_as_irq(chip, d->hwirq); - module_put(chip->owner); + module_put(chip->gpiodev->owner); } static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) @@ -985,10 +1072,10 @@ int gpiod_request(struct gpio_desc *desc, const char *label) if (!chip) goto done; - if (try_module_get(chip->owner)) { + if (try_module_get(chip->gpiodev->owner)) { status = __gpiod_request(desc, label); if (status < 0) - module_put(chip->owner); + module_put(chip->gpiodev->owner); } done: @@ -1034,7 +1121,7 @@ static bool __gpiod_free(struct gpio_desc *desc) void gpiod_free(struct gpio_desc *desc) { if (desc && __gpiod_free(desc)) - module_put(desc->chip->owner); + module_put(desc->chip->gpiodev->owner); else WARN_ON(extra_checks); } @@ -2492,16 +2579,16 @@ static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip) static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) { unsigned long flags; - struct gpio_chip *chip = NULL; + struct gpio_device *gdev = NULL; loff_t index = *pos; s->private = ""; spin_lock_irqsave(&gpio_lock, flags); - list_for_each_entry(chip, &gpio_chips, list) + list_for_each_entry(gdev, &gpio_devices, list) if (index-- == 0) { spin_unlock_irqrestore(&gpio_lock, flags); - return chip; + return gdev; } spin_unlock_irqrestore(&gpio_lock, flags); @@ -2511,14 +2598,14 @@ static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) { unsigned long flags; - struct gpio_chip *chip = v; + struct gpio_device *gdev = v; void *ret = NULL; spin_lock_irqsave(&gpio_lock, flags); - if (list_is_last(&chip->list, &gpio_chips)) + if (list_is_last(&gdev->list, &gpio_devices)) ret = NULL; else - ret = list_entry(chip->list.next, struct gpio_chip, list); + ret = list_entry(gdev->list.next, struct gpio_device, list); spin_unlock_irqrestore(&gpio_lock, flags); s->private = "\n"; @@ -2533,15 +2620,24 @@ static void gpiolib_seq_stop(struct seq_file *s, void *v) static int gpiolib_seq_show(struct seq_file *s, void *v) { - struct gpio_chip *chip = v; - struct device *dev; + struct gpio_device *gdev = v; + struct gpio_chip *chip = gdev->chip; + struct device *parent; + + if (!chip) { + seq_printf(s, "%s%s: (dangling chip)", (char *)s->private, + dev_name(&gdev->dev)); + return 0; + } - seq_printf(s, "%sGPIOs %d-%d", (char *)s->private, - chip->base, chip->base + chip->ngpio - 1); - dev = chip->parent; - if (dev) - seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus", - dev_name(dev)); + seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private, + dev_name(&gdev->dev), + chip->base, chip->base + chip->ngpio - 1); + parent = chip->parent; + if (parent) + seq_printf(s, ", parent: %s/%s", + parent->bus ? parent->bus->name : "no-bus", + dev_name(parent)); if (chip->label) seq_printf(s, ", %s", chip->label); if (chip->can_sleep) diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 99ed3b00ffe9..feea2c823e47 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -12,14 +12,39 @@ #ifndef GPIOLIB_H #define GPIOLIB_H +#include <linux/gpio/driver.h> #include <linux/err.h> #include <linux/device.h> +#include <linux/module.h> +#include <linux/cdev.h> enum of_gpio_flags; enum gpiod_flags; struct acpi_device; /** + * struct gpio_device - internal state container for GPIO devices + * @id: numerical ID number for the GPIO chip + * @dev: the GPIO device struct + * @owner: helps prevent removal of modules exporting active GPIOs + * @chip: pointer to the corresponding gpiochip, holding static + * data for this device + * @list: links gpio_device:s together for traversal + * + * This state container holds most of the runtime variable data + * for a GPIO device and can hold references and live on after the + * GPIO chip has been removed, if it is still being used from + * userspace. + */ +struct gpio_device { + int id; + struct device dev; + struct module *owner; + struct gpio_chip *chip; + struct list_head list; +}; + +/** * struct acpi_gpio_info - ACPI GPIO specific information * @gpioint: if %true this GPIO is of type GpioInt otherwise type is GpioIo * @active_low: in case of @gpioint, the pin is active low @@ -90,7 +115,7 @@ struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np, struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, u16 hwnum); extern struct spinlock gpio_lock; -extern struct list_head gpio_chips; +extern struct list_head gpio_devices; struct gpio_desc { struct gpio_chip *chip; diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 82fda487453f..f3f1dbd43c9b 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -1,6 +1,7 @@ #ifndef __LINUX_GPIO_DRIVER_H #define __LINUX_GPIO_DRIVER_H +#include <linux/device.h> #include <linux/types.h> #include <linux/module.h> #include <linux/irq.h> @@ -10,22 +11,22 @@ #include <linux/pinctrl/pinctrl.h> #include <linux/kconfig.h> -struct device; struct gpio_desc; struct of_phandle_args; struct device_node; struct seq_file; +struct gpio_device; #ifdef CONFIG_GPIOLIB /** * struct gpio_chip - abstract a GPIO controller * @label: for diagnostics + * @gpiodev: the internal state holder, opaque struct * @parent: optional parent device providing the GPIOs * @cdev: class device used by sysfs interface (may be NULL) * @owner: helps prevent removal of modules exporting active GPIOs * @data: per-instance data assigned by the driver - * @list: links gpio_chips together for traversal * @request: optional hook for chip-specific activation, such as * enabling module power and clock; may sleep * @free: optional hook for chip-specific deactivation, such as @@ -107,11 +108,11 @@ struct seq_file; */ struct gpio_chip { const char *label; + struct gpio_device *gpiodev; struct device *parent; struct device *cdev; struct module *owner; void *data; - struct list_head list; int (*request)(struct gpio_chip *chip, unsigned offset); |