diff options
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 409 |
1 files changed, 215 insertions, 194 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4756ea08894f..99a2c77c3711 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1,33 +1,35 @@ // SPDX-License-Identifier: GPL-2.0 +#include <linux/acpi.h> #include <linux/bitmap.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/interrupt.h> -#include <linux/irq.h> -#include <linux/spinlock.h> -#include <linux/list.h> +#include <linux/compat.h> +#include <linux/debugfs.h> #include <linux/device.h> #include <linux/err.h> -#include <linux/debugfs.h> -#include <linux/seq_file.h> +#include <linux/file.h> +#include <linux/fs.h> #include <linux/gpio.h> -#include <linux/idr.h> -#include <linux/slab.h> -#include <linux/acpi.h> #include <linux/gpio/driver.h> #include <linux/gpio/machine.h> +#include <linux/idr.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> #include <linux/pinctrl/consumer.h> -#include <linux/fs.h> -#include <linux/compat.h> -#include <linux/file.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + #include <uapi/linux/gpio.h> -#include "gpiolib.h" -#include "gpiolib-of.h" #include "gpiolib-acpi.h" #include "gpiolib-cdev.h" +#include "gpiolib-of.h" +#include "gpiolib-swnode.h" #include "gpiolib-sysfs.h" +#include "gpiolib.h" #define CREATE_TRACE_POINTS #include <trace/events/gpio.h> @@ -183,14 +185,14 @@ EXPORT_SYMBOL_GPL(gpiod_to_chip); static int gpiochip_find_base(int ngpio) { struct gpio_device *gdev; - int base = ARCH_NR_GPIOS - ngpio; + int base = GPIO_DYNAMIC_BASE; - list_for_each_entry_reverse(gdev, &gpio_devices, list) { + list_for_each_entry(gdev, &gpio_devices, list) { /* found a free space? */ - if (gdev->base + gdev->ngpio <= base) + if (gdev->base >= base + ngpio) break; - /* nope, check the space right before the chip */ - base = gdev->base - ngpio; + /* nope, check the space right after the chip */ + base = gdev->base + gdev->ngpio; } if (gpio_is_valid(base)) { @@ -366,12 +368,12 @@ static int gpiochip_set_desc_names(struct gpio_chip *gc) static int devprop_gpiochip_set_names(struct gpio_chip *chip) { struct gpio_device *gdev = chip->gpiodev; - struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev); + struct device *dev = &gdev->dev; const char **names; int ret, i; int count; - count = fwnode_property_string_array_count(fwnode, "gpio-line-names"); + count = device_property_string_array_count(dev, "gpio-line-names"); if (count < 0) return 0; @@ -384,7 +386,7 @@ static int devprop_gpiochip_set_names(struct gpio_chip *chip) * gpiochips. */ if (count <= chip->offset) { - dev_warn(&gdev->dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n", + dev_warn(dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n", count, chip->offset); return 0; } @@ -393,10 +395,10 @@ static int devprop_gpiochip_set_names(struct gpio_chip *chip) if (!names) return -ENOMEM; - ret = fwnode_property_read_string_array(fwnode, "gpio-line-names", + ret = device_property_read_string_array(dev, "gpio-line-names", names, count); if (ret < 0) { - dev_warn(&gdev->dev, "failed to read GPIO line names\n"); + dev_warn(dev, "failed to read GPIO line names\n"); kfree(names); return ret; } @@ -445,9 +447,22 @@ static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc) return p; } +static unsigned int gpiochip_count_reserved_ranges(struct gpio_chip *gc) +{ + struct device *dev = &gc->gpiodev->dev; + int size; + + /* Format is "start, count, ..." */ + size = device_property_count_u32(dev, "gpio-reserved-ranges"); + if (size > 0 && size % 2 == 0) + return size; + + return 0; +} + static int gpiochip_alloc_valid_mask(struct gpio_chip *gc) { - if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask)) + if (!(gpiochip_count_reserved_ranges(gc) || gc->init_valid_mask)) return 0; gc->valid_mask = gpiochip_allocate_mask(gc); @@ -457,8 +472,50 @@ static int gpiochip_alloc_valid_mask(struct gpio_chip *gc) return 0; } +static int gpiochip_apply_reserved_ranges(struct gpio_chip *gc) +{ + struct device *dev = &gc->gpiodev->dev; + unsigned int size; + u32 *ranges; + int ret; + + size = gpiochip_count_reserved_ranges(gc); + if (size == 0) + return 0; + + ranges = kmalloc_array(size, sizeof(*ranges), GFP_KERNEL); + if (!ranges) + return -ENOMEM; + + ret = device_property_read_u32_array(dev, "gpio-reserved-ranges", + ranges, size); + if (ret) { + kfree(ranges); + return ret; + } + + while (size) { + u32 count = ranges[--size]; + u32 start = ranges[--size]; + + if (start >= gc->ngpio || start + count > gc->ngpio) + continue; + + bitmap_clear(gc->valid_mask, start, count); + } + + kfree(ranges); + return 0; +} + static int gpiochip_init_valid_mask(struct gpio_chip *gc) { + int ret; + + ret = gpiochip_apply_reserved_ranges(gc); + if (ret) + return ret; + if (gc->init_valid_mask) return gc->init_valid_mask(gc, gc->valid_mask, @@ -475,6 +532,14 @@ static void gpiochip_free_valid_mask(struct gpio_chip *gc) static int gpiochip_add_pin_ranges(struct gpio_chip *gc) { + /* + * Device Tree platforms are supposed to use "gpio-ranges" + * property. This check ensures that the ->add_pin_ranges() + * won't be called for them. + */ + if (device_property_present(&gc->gpiodev->dev, "gpio-ranges")) + return 0; + if (gc->add_pin_ranges) return gc->add_pin_ranges(gc); @@ -493,7 +558,7 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); static void gpiodevice_release(struct device *dev) { - struct gpio_device *gdev = container_of(dev, struct gpio_device, dev); + struct gpio_device *gdev = to_gpio_device(dev); unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); @@ -526,12 +591,13 @@ static int gpiochip_setup_dev(struct gpio_device *gdev) if (ret) return ret; + /* From this point, the .release() function cleans up gpio_device */ + gdev->dev.release = gpiodevice_release; + ret = gpiochip_sysfs_register(gdev); if (ret) goto err_remove_device; - /* From this point, the .release() function cleans up gpio_device */ - gdev->dev.release = gpiodevice_release; dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base, gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic"); @@ -597,15 +663,17 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, struct fwnode_handle *fwnode = NULL; struct gpio_device *gdev; unsigned long flags; - int base = gc->base; unsigned int i; + u32 ngpios = 0; + int base = 0; int ret = 0; - u32 ngpios; + /* If the calling driver did not initialize firmware node, do it here */ if (gc->fwnode) fwnode = gc->fwnode; else if (gc->parent) fwnode = dev_fwnode(gc->parent); + gc->fwnode = fwnode; /* * First: allocate and populate the internal stat container, and @@ -619,14 +687,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, gdev->chip = gc; gc->gpiodev = gdev; - of_gpio_dev_init(gc, gdev); - acpi_gpio_dev_init(gc, gdev); - - /* - * Assign fwnode depending on the result of the previous calls, - * if none of them succeed, assign it to the parent's one. - */ - gdev->dev.fwnode = dev_fwnode(&gdev->dev) ?: fwnode; + device_set_node(&gdev->dev, gc->fwnode); gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL); if (gdev->id < 0) { @@ -647,17 +708,12 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, else gdev->owner = THIS_MODULE; - gdev->descs = kcalloc(gc->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL); - if (!gdev->descs) { - ret = -ENOMEM; - goto err_free_dev_name; - } - /* * Try the device properties if the driver didn't supply the number * of GPIO lines. */ - if (gc->ngpio == 0) { + ngpios = gc->ngpio; + if (ngpios == 0) { ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios); if (ret == -ENODATA) /* @@ -668,7 +724,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, */ ngpios = 0; else if (ret) - goto err_free_descs; + goto err_free_dev_name; gc->ngpio = ngpios; } @@ -676,13 +732,19 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, if (gc->ngpio == 0) { chip_err(gc, "tried to insert a GPIO chip with zero lines\n"); ret = -EINVAL; - goto err_free_descs; + goto err_free_dev_name; } if (gc->ngpio > FASTPATH_NGPIO) chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n", gc->ngpio, FASTPATH_NGPIO); + gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL); + if (!gdev->descs) { + ret = -ENOMEM; + goto err_free_dev_name; + } + gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL); if (!gdev->label) { ret = -ENOMEM; @@ -701,11 +763,13 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, * it may be a pipe dream. It will not happen before we get rid * of the sysfs interface anyways. */ + base = gc->base; if (base < 0) { base = gpiochip_find_base(gc->ngpio); if (base < 0) { - ret = base; spin_unlock_irqrestore(&gpio_lock, flags); + ret = base; + base = 0; goto err_free_label; } /* @@ -715,6 +779,9 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, * a poison instead. */ gc->base = base; + } else { + dev_warn(&gdev->dev, + "Static allocation of GPIO base is deprecated, use dynamic allocation.\n"); } gdev->base = base; @@ -731,6 +798,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, spin_unlock_irqrestore(&gpio_lock, flags); BLOCKING_INIT_NOTIFIER_HEAD(&gdev->notifier); + init_rwsem(&gdev->sem); #ifdef CONFIG_PINCTRL INIT_LIST_HEAD(&gdev->pin_ranges); @@ -816,6 +884,11 @@ err_remove_of_chip: err_free_gpiochip_mask: gpiochip_remove_pin_ranges(gc); gpiochip_free_valid_mask(gc); + if (gdev->dev.release) { + /* release() has been registered by gpiochip_setup_dev() */ + gpio_device_put(gdev); + goto err_print_message; + } err_remove_from_list: spin_lock_irqsave(&gpio_lock, flags); list_del(&gdev->list); @@ -829,13 +902,14 @@ err_free_dev_name: err_free_ida: ida_free(&gpio_ida, gdev->id); err_free_gdev: + kfree(gdev); +err_print_message: /* failures here can mean systems won't boot... */ if (ret != -EPROBE_DEFER) { pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__, - gdev->base, gdev->base + gdev->ngpio - 1, + base, base + (int)ngpios - 1, gc->label ? : "generic", ret); } - kfree(gdev); return ret; } EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key); @@ -865,6 +939,8 @@ void gpiochip_remove(struct gpio_chip *gc) unsigned long flags; unsigned int i; + down_write(&gdev->sem); + /* FIXME: should the legacy sysfs handling be moved to gpio_device? */ gpiochip_sysfs_unregister(gdev); gpiochip_free_hogs(gc); @@ -899,7 +975,8 @@ void gpiochip_remove(struct gpio_chip *gc) * gone. */ gcdev_unregister(gdev); - put_device(&gdev->dev); + up_write(&gdev->sem); + gpio_device_put(gdev); } EXPORT_SYMBOL_GPL(gpiochip_remove); @@ -1053,14 +1130,8 @@ static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc, /* Just pick something */ fwspec.param[1] = IRQ_TYPE_EDGE_RISING; fwspec.param_count = 2; - ret = __irq_domain_alloc_irqs(gc->irq.domain, - /* just pick something */ - -1, - 1, - NUMA_NO_NODE, - &fwspec, - false, - NULL); + ret = irq_domain_alloc_irqs(gc->irq.domain, 1, + NUMA_NO_NODE, &fwspec); if (ret < 0) { chip_err(gc, "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n", @@ -1990,17 +2061,15 @@ static int validate_desc(const struct gpio_desc *desc, const char *func) int gpiod_request(struct gpio_desc *desc, const char *label) { int ret = -EPROBE_DEFER; - struct gpio_device *gdev; VALIDATE_DESC(desc); - gdev = desc->gdev; - if (try_module_get(gdev->owner)) { + if (try_module_get(desc->gdev->owner)) { ret = gpiod_request_commit(desc, label); if (ret) - module_put(gdev->owner); + module_put(desc->gdev->owner); else - get_device(&gdev->dev); + gpio_device_get(desc->gdev); } if (ret) @@ -2061,7 +2130,7 @@ void gpiod_free(struct gpio_desc *desc) { if (desc && desc->gdev && gpiod_free_commit(desc)) { module_put(desc->gdev->owner); - put_device(&desc->gdev->dev); + gpio_device_put(desc->gdev); } else { WARN_ON(extra_checks); } @@ -3798,62 +3867,88 @@ static int platform_gpio_count(struct device *dev, const char *con_id) return count; } -/** - * fwnode_get_named_gpiod - obtain a GPIO from firmware node - * @fwnode: handle of the firmware node - * @propname: name of the firmware property representing the GPIO - * @index: index of the GPIO to obtain for the consumer - * @dflags: GPIO initialization flags - * @label: label to attach to the requested GPIO - * - * This function can be used for drivers that get their configuration - * from opaque firmware. - * - * The function properly finds the corresponding GPIO using whatever is the - * underlying firmware interface and then makes sure that the GPIO - * descriptor is requested before it is returned to the caller. - * - * Returns: - * On successful request the GPIO pin is configured in accordance with - * provided @dflags. - * - * In case of error an ERR_PTR() is returned. - */ -static struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, - const char *propname, int index, - enum gpiod_flags dflags, - const char *label) +static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode, + struct device *consumer, + const char *con_id, + unsigned int idx, + enum gpiod_flags *flags, + unsigned long *lookupflags) { - unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT; - struct gpio_desc *desc = ERR_PTR(-ENODEV); - int ret; + struct gpio_desc *desc = ERR_PTR(-ENOENT); if (is_of_node(fwnode)) { - desc = gpiod_get_from_of_node(to_of_node(fwnode), - propname, index, - dflags, - label); - return desc; + dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", + fwnode, con_id); + desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags); } else if (is_acpi_node(fwnode)) { - struct acpi_gpio_info info; + dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", + fwnode, con_id); + desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags); + } else if (is_software_node(fwnode)) { + dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", + fwnode, con_id); + desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags); + } - desc = acpi_node_get_gpiod(fwnode, propname, index, &info); - if (IS_ERR(desc)) - return desc; + return desc; +} - acpi_gpio_update_gpiod_flags(&dflags, &info); - acpi_gpio_update_gpiod_lookup_flags(&lflags, &info); - } else { - return ERR_PTR(-EINVAL); +static struct gpio_desc *gpiod_find_and_request(struct device *consumer, + struct fwnode_handle *fwnode, + const char *con_id, + unsigned int idx, + enum gpiod_flags flags, + const char *label, + bool platform_lookup_allowed) +{ + unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT; + struct gpio_desc *desc = ERR_PTR(-ENOENT); + int ret; + + if (!IS_ERR_OR_NULL(fwnode)) + desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx, + &flags, &lookupflags); + + if (gpiod_not_found(desc) && platform_lookup_allowed) { + /* + * Either we are not using DT or ACPI, or their lookup did not + * return a result. In that case, use platform lookup as a + * fallback. + */ + dev_dbg(consumer, "using lookup tables for GPIO lookup\n"); + desc = gpiod_find(consumer, con_id, idx, &lookupflags); } - /* Currently only ACPI takes this path */ + if (IS_ERR(desc)) { + dev_dbg(consumer, "No GPIO consumer %s found\n", con_id); + return desc; + } + + /* + * If a connection label was passed use that, else attempt to use + * the device name as label + */ ret = gpiod_request(desc, label); - if (ret) - return ERR_PTR(ret); + if (ret) { + if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE)) + return ERR_PTR(ret); + + /* + * This happens when there are several consumers for + * the same GPIO line: we just return here without + * further initialization. It is a bit of a hack. + * This is necessary to support fixed regulators. + * + * FIXME: Make this more sane and safe. + */ + dev_info(consumer, + "nonexclusive access to GPIO for %s\n", con_id); + return desc; + } - ret = gpiod_configure_flags(desc, propname, lflags, dflags); + ret = gpiod_configure_flags(desc, con_id, lookupflags, flags); if (ret < 0) { + dev_dbg(consumer, "setup of GPIO %s failed\n", con_id); gpiod_put(desc); return ERR_PTR(ret); } @@ -3886,29 +3981,12 @@ static struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, * In case of error an ERR_PTR() is returned. */ struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode, - const char *con_id, int index, + const char *con_id, + int index, enum gpiod_flags flags, const char *label) { - struct gpio_desc *desc; - char prop_name[32]; /* 32 is max size of property name */ - unsigned int i; - - for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { - if (con_id) - snprintf(prop_name, sizeof(prop_name), "%s-%s", - con_id, gpio_suffixes[i]); - else - snprintf(prop_name, sizeof(prop_name), "%s", - gpio_suffixes[i]); - - desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags, - label); - if (!gpiod_not_found(desc)) - break; - } - - return desc; + return gpiod_find_and_request(NULL, fwnode, con_id, index, flags, label, false); } EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index); @@ -3927,6 +4005,8 @@ int gpiod_count(struct device *dev, const char *con_id) count = of_gpio_get_count(dev, con_id); else if (is_acpi_node(fwnode)) count = acpi_gpio_count(dev, con_id); + else if (is_software_node(fwnode)) + count = swnode_gpio_count(fwnode, con_id); if (count < 0) count = platform_gpio_count(dev, con_id); @@ -4062,70 +4142,11 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, unsigned int idx, enum gpiod_flags flags) { - unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT; - struct gpio_desc *desc = NULL; - int ret; - /* Maybe we have a device name, maybe not */ + struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL; const char *devname = dev ? dev_name(dev) : "?"; - const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL; - - dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id); - - /* Using device tree? */ - if (is_of_node(fwnode)) { - dev_dbg(dev, "using device tree for GPIO lookup\n"); - desc = of_find_gpio(dev, con_id, idx, &lookupflags); - } else if (is_acpi_node(fwnode)) { - dev_dbg(dev, "using ACPI for GPIO lookup\n"); - desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags); - } - - /* - * Either we are not using DT or ACPI, or their lookup did not return - * a result. In that case, use platform lookup as a fallback. - */ - if (!desc || gpiod_not_found(desc)) { - dev_dbg(dev, "using lookup tables for GPIO lookup\n"); - desc = gpiod_find(dev, con_id, idx, &lookupflags); - } - - if (IS_ERR(desc)) { - dev_dbg(dev, "No GPIO consumer %s found\n", con_id); - return desc; - } - - /* - * If a connection label was passed use that, else attempt to use - * the device name as label - */ - ret = gpiod_request(desc, con_id ?: devname); - if (ret) { - if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE)) - return ERR_PTR(ret); - - /* - * This happens when there are several consumers for - * the same GPIO line: we just return here without - * further initialization. It is a bit of a hack. - * This is necessary to support fixed regulators. - * - * FIXME: Make this more sane and safe. - */ - dev_info(dev, "nonexclusive access to GPIO for %s\n", con_id ?: devname); - return desc; - } + const char *label = con_id ?: devname; - ret = gpiod_configure_flags(desc, con_id, lookupflags, flags); - if (ret < 0) { - dev_dbg(dev, "setup of GPIO %s failed\n", con_id); - gpiod_put(desc); - return ERR_PTR(ret); - } - - blocking_notifier_call_chain(&desc->gdev->notifier, - GPIOLINE_CHANGED_REQUESTED, desc); - - return desc; + return gpiod_find_and_request(dev, fwnode, con_id, idx, flags, label, true); } EXPORT_SYMBOL_GPL(gpiod_get_index); |