kernel/irq/devres.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <linux/module.h>
0003 #include <linux/interrupt.h>
0004 #include <linux/device.h>
0005 #include <linux/gfp.h>
0006 #include <linux/irq.h>
0007
0008 #include "internals.h"
0009
0010 /*
0011  * Device resource management aware IRQ request/free implementation.
0012  */
0013 struct irq_devres {
0014     unsigned int irq;
0015     void *dev_id;
0016 };
0017
0018 static void devm_irq_release(struct device *dev, void *res)
0019 {
0020     struct irq_devres *this = res;
0021
0022     free_irq(this->irq, this->dev_id);
0023 }
0024
0025 static int devm_irq_match(struct device *dev, void *res, void *data)
0026 {
0027     struct irq_devres *this = res, *match = data;
0028
0029     return this->irq == match->irq && this->dev_id == match->dev_id;
0030 }
0031
0032 /**
0033  *  devm_request_threaded_irq - allocate an interrupt line for a managed device
0034  *  @dev: device to request interrupt for
0035  *  @irq: Interrupt line to allocate
0036  *  @handler: Function to be called when the IRQ occurs
0037  *  @thread_fn: function to be called in a threaded interrupt context. NULL
0038  *          for devices which handle everything in @handler
0039  *  @irqflags: Interrupt type flags
0040  *  @devname: An ascii name for the claiming device, dev_name(dev) if NULL
0041  *  @dev_id: A cookie passed back to the handler function
0042  *
0043  *  Except for the extra @dev argument, this function takes the
0044  *  same arguments and performs the same function as
0045  *  request_threaded_irq().  IRQs requested with this function will be
0046  *  automatically freed on driver detach.
0047  *
0048  *  If an IRQ allocated with this function needs to be freed
0049  *  separately, devm_free_irq() must be used.
0050  */
0051 int devm_request_threaded_irq(struct device *dev, unsigned int irq,
0052                   irq_handler_t handler, irq_handler_t thread_fn,
0053                   unsigned long irqflags, const char *devname,
0054                   void *dev_id)
0055 {
0056     struct irq_devres *dr;
0057     int rc;
0058
0059     dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
0060               GFP_KERNEL);
0061     if (!dr)
0062         return -ENOMEM;
0063
0064     if (!devname)
0065         devname = dev_name(dev);
0066
0067     rc = request_threaded_irq(irq, handler, thread_fn, irqflags, devname,
0068                   dev_id);
0069     if (rc) {
0070         devres_free(dr);
0071         return rc;
0072     }
0073
0074     dr->irq = irq;
0075     dr->dev_id = dev_id;
0076     devres_add(dev, dr);
0077
0078     return 0;
0079 }
0080 EXPORT_SYMBOL(devm_request_threaded_irq);
0081
0082 /**
0083  *  devm_request_any_context_irq - allocate an interrupt line for a managed device
0084  *  @dev: device to request interrupt for
0085  *  @irq: Interrupt line to allocate
0086  *  @handler: Function to be called when the IRQ occurs
0087  *  @irqflags: Interrupt type flags
0088  *  @devname: An ascii name for the claiming device, dev_name(dev) if NULL
0089  *  @dev_id: A cookie passed back to the handler function
0090  *
0091  *  Except for the extra @dev argument, this function takes the
0092  *  same arguments and performs the same function as
0093  *  request_any_context_irq().  IRQs requested with this function will be
0094  *  automatically freed on driver detach.
0095  *
0096  *  If an IRQ allocated with this function needs to be freed
0097  *  separately, devm_free_irq() must be used.
0098  */
0099 int devm_request_any_context_irq(struct device *dev, unsigned int irq,
0100                   irq_handler_t handler, unsigned long irqflags,
0101                   const char *devname, void *dev_id)
0102 {
0103     struct irq_devres *dr;
0104     int rc;
0105
0106     dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
0107               GFP_KERNEL);
0108     if (!dr)
0109         return -ENOMEM;
0110
0111     if (!devname)
0112         devname = dev_name(dev);
0113
0114     rc = request_any_context_irq(irq, handler, irqflags, devname, dev_id);
0115     if (rc < 0) {
0116         devres_free(dr);
0117         return rc;
0118     }
0119
0120     dr->irq = irq;
0121     dr->dev_id = dev_id;
0122     devres_add(dev, dr);
0123
0124     return rc;
0125 }
0126 EXPORT_SYMBOL(devm_request_any_context_irq);
0127
0128 /**
0129  *  devm_free_irq - free an interrupt
0130  *  @dev: device to free interrupt for
0131  *  @irq: Interrupt line to free
0132  *  @dev_id: Device identity to free
0133  *
0134  *  Except for the extra @dev argument, this function takes the
0135  *  same arguments and performs the same function as free_irq().
0136  *  This function instead of free_irq() should be used to manually
0137  *  free IRQs allocated with devm_request_irq().
0138  */
0139 void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
0140 {
0141     struct irq_devres match_data = { irq, dev_id };
0142
0143     WARN_ON(devres_destroy(dev, devm_irq_release, devm_irq_match,
0144                    &match_data));
0145     free_irq(irq, dev_id);
0146 }
0147 EXPORT_SYMBOL(devm_free_irq);
0148
0149 struct irq_desc_devres {
0150     unsigned int from;
0151     unsigned int cnt;
0152 };
0153
0154 static void devm_irq_desc_release(struct device *dev, void *res)
0155 {
0156     struct irq_desc_devres *this = res;
0157
0158     irq_free_descs(this->from, this->cnt);
0159 }
0160
0161 /**
0162  * __devm_irq_alloc_descs - Allocate and initialize a range of irq descriptors
0163  *              for a managed device
0164  * @dev:    Device to allocate the descriptors for
0165  * @irq:    Allocate for specific irq number if irq >= 0
0166  * @from:   Start the search from this irq number
0167  * @cnt:    Number of consecutive irqs to allocate
0168  * @node:   Preferred node on which the irq descriptor should be allocated
0169  * @owner:  Owning module (can be NULL)
0170  * @affinity:   Optional pointer to an irq_affinity_desc array of size @cnt
0171  *      which hints where the irq descriptors should be allocated
0172  *      and which default affinities to use
0173  *
0174  * Returns the first irq number or error code.
0175  *
0176  * Note: Use the provided wrappers (devm_irq_alloc_desc*) for simplicity.
0177  */
0178 int __devm_irq_alloc_descs(struct device *dev, int irq, unsigned int from,
0179                unsigned int cnt, int node, struct module *owner,
0180                const struct irq_affinity_desc *affinity)
0181 {
0182     struct irq_desc_devres *dr;
0183     int base;
0184
0185     dr = devres_alloc(devm_irq_desc_release, sizeof(*dr), GFP_KERNEL);
0186     if (!dr)
0187         return -ENOMEM;
0188
0189     base = __irq_alloc_descs(irq, from, cnt, node, owner, affinity);
0190     if (base < 0) {
0191         devres_free(dr);
0192         return base;
0193     }
0194
0195     dr->from = base;
0196     dr->cnt = cnt;
0197     devres_add(dev, dr);
0198
0199     return base;
0200 }
0201 EXPORT_SYMBOL_GPL(__devm_irq_alloc_descs);
0202
0203 #ifdef CONFIG_GENERIC_IRQ_CHIP
0204 /**
0205  * devm_irq_alloc_generic_chip - Allocate and initialize a generic chip
0206  *                               for a managed device
0207  * @dev:    Device to allocate the generic chip for
0208  * @name:   Name of the irq chip
0209  * @num_ct: Number of irq_chip_type instances associated with this
0210  * @irq_base:   Interrupt base nr for this chip
0211  * @reg_base:   Register base address (virtual)
0212  * @handler:    Default flow handler associated with this chip
0213  *
0214  * Returns an initialized irq_chip_generic structure. The chip defaults
0215  * to the primary (index 0) irq_chip_type and @handler
0216  */
0217 struct irq_chip_generic *
0218 devm_irq_alloc_generic_chip(struct device *dev, const char *name, int num_ct,
0219                 unsigned int irq_base, void __iomem *reg_base,
0220                 irq_flow_handler_t handler)
0221 {
0222     struct irq_chip_generic *gc;
0223
0224     gc = devm_kzalloc(dev, struct_size(gc, chip_types, num_ct), GFP_KERNEL);
0225     if (gc)
0226         irq_init_generic_chip(gc, name, num_ct,
0227                       irq_base, reg_base, handler);
0228
0229     return gc;
0230 }
0231 EXPORT_SYMBOL_GPL(devm_irq_alloc_generic_chip);
0232
0233 struct irq_generic_chip_devres {
0234     struct irq_chip_generic *gc;
0235     u32 msk;
0236     unsigned int clr;
0237     unsigned int set;
0238 };
0239
0240 static void devm_irq_remove_generic_chip(struct device *dev, void *res)
0241 {
0242     struct irq_generic_chip_devres *this = res;
0243
0244     irq_remove_generic_chip(this->gc, this->msk, this->clr, this->set);
0245 }
0246
0247 /**
0248  * devm_irq_setup_generic_chip - Setup a range of interrupts with a generic
0249  *                               chip for a managed device
0250  *
0251  * @dev:    Device to setup the generic chip for
0252  * @gc:     Generic irq chip holding all data
0253  * @msk:    Bitmask holding the irqs to initialize relative to gc->irq_base
0254  * @flags:  Flags for initialization
0255  * @clr:    IRQ_* bits to clear
0256  * @set:    IRQ_* bits to set
0257  *
0258  * Set up max. 32 interrupts starting from gc->irq_base. Note, this
0259  * initializes all interrupts to the primary irq_chip_type and its
0260  * associated handler.
0261  */
0262 int devm_irq_setup_generic_chip(struct device *dev, struct irq_chip_generic *gc,
0263                 u32 msk, enum irq_gc_flags flags,
0264                 unsigned int clr, unsigned int set)
0265 {
0266     struct irq_generic_chip_devres *dr;
0267
0268     dr = devres_alloc(devm_irq_remove_generic_chip,
0269               sizeof(*dr), GFP_KERNEL);
0270     if (!dr)
0271         return -ENOMEM;
0272
0273     irq_setup_generic_chip(gc, msk, flags, clr, set);
0274
0275     dr->gc = gc;
0276     dr->msk = msk;
0277     dr->clr = clr;
0278     dr->set = set;
0279     devres_add(dev, dr);
0280
0281     return 0;
0282 }
0283 EXPORT_SYMBOL_GPL(devm_irq_setup_generic_chip);
0284 #endif /* CONFIG_GENERIC_IRQ_CHIP */