/* * OMAP2+ common Power & Reset Management (PRM) IP block functions * * Copyright (C) 2011 Texas Instruments, Inc. * Tero Kristo <t-kristo@ti.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * * For historical purposes, the API used to configure the PRM * interrupt handler refers to it as the "PRCM interrupt." The * underlying registers are located in the PRM on OMAP3/4. * * XXX This code should eventually be moved to a PRM driver. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/io.h> #include <linux/irq.h> #include <linux/interrupt.h> #include <linux/slab.h> #include <plat/common.h> #include <plat/prcm.h> #include <plat/irqs.h> #include "prm2xxx_3xxx.h" #include "prm44xx.h" /* * OMAP_PRCM_MAX_NR_PENDING_REG: maximum number of PRM_IRQ*_MPU regs * XXX this is technically not needed, since * omap_prcm_register_chain_handler() could allocate this based on the * actual amount of memory needed for the SoC */ #define OMAP_PRCM_MAX_NR_PENDING_REG 2 /* * prcm_irq_chips: an array of all of the "generic IRQ chips" in use * by the PRCM interrupt handler code. There will be one 'chip' per * PRM_{IRQSTATUS,IRQENABLE}_MPU register pair. (So OMAP3 will have * one "chip" and OMAP4 will have two.) */ static struct irq_chip_generic **prcm_irq_chips; /* * prcm_irq_setup: the PRCM IRQ parameters for the hardware the code * is currently running on. Defined and passed by initialization code * that calls omap_prcm_register_chain_handler(). */ static struct omap_prcm_irq_setup *prcm_irq_setup; /* Private functions */ /* * Move priority events from events to priority_events array */ static void omap_prcm_events_filter_priority(unsigned long *events, unsigned long *priority_events) { int i; for (i = 0; i < prcm_irq_setup->nr_regs; i++) { priority_events[i] = events[i] & prcm_irq_setup->priority_mask[i]; events[i] ^= priority_events[i]; } } /* * PRCM Interrupt Handler * * This is a common handler for the OMAP PRCM interrupts. Pending * interrupts are detected by a call to prcm_pending_events and * dispatched accordingly. Clearing of the wakeup events should be * done by the SoC specific individual handlers. */ static void omap_prcm_irq_handler(unsigned int irq, struct irq_desc *desc) { unsigned long pending[OMAP_PRCM_MAX_NR_PENDING_REG]; unsigned long priority_pending[OMAP_PRCM_MAX_NR_PENDING_REG]; struct irq_chip *chip = irq_desc_get_chip(desc); unsigned int virtirq; int nr_irqs = prcm_irq_setup->nr_regs * 32; /* * If we are suspended, mask all interrupts from PRCM level, * this does not ack them, and they will be pending until we * re-enable the interrupts, at which point the * omap_prcm_irq_handler will be executed again. The * _save_and_clear_irqen() function must ensure that the PRM * write to disable all IRQs has reached the PRM before * returning, or spurious PRCM interrupts may occur during * suspend. */ if (prcm_irq_setup->suspended) { prcm_irq_setup->save_and_clear_irqen(prcm_irq_setup->saved_mask); prcm_irq_setup->suspend_save_flag = true; } /* * Loop until all pending irqs are handled, since * generic_handle_irq() can cause new irqs to come */ while (!prcm_irq_setup->suspended) { prcm_irq_setup->read_pending_irqs(pending); /* No bit set, then all IRQs are handled */ if (find_first_bit(pending, nr_irqs) >= nr_irqs) break; omap_prcm_events_filter_priority(pending, priority_pending); /* * Loop on all currently pending irqs so that new irqs * cannot starve previously pending irqs */ /* Serve priority events first */ for_each_set_bit(virtirq, priority_pending, nr_irqs) generic_handle_irq(prcm_irq_setup->base_irq + virtirq); /* Serve normal events next */ for_each_set_bit(virtirq, pending, nr_irqs) generic_handle_irq(prcm_irq_setup->base_irq + virtirq); } if (chip->irq_ack) chip->irq_ack(&desc->irq_data); if (chip->irq_eoi) chip->irq_eoi(&desc->irq_data); chip->irq_unmask(&desc->irq_data); prcm_irq_setup->ocp_barrier(); /* avoid spurious IRQs */ } /* Public functions */ /** * omap_prcm_event_to_irq - given a PRCM event name, returns the * corresponding IRQ on which the handler should be registered * @name: name of the PRCM interrupt bit to look up - see struct omap_prcm_irq * * Returns the Linux internal IRQ ID corresponding to @name upon success, * or -ENOENT upon failure. */ int omap_prcm_event_to_irq(const char *name) { int i; if (!prcm_irq_setup || !name) return -ENOENT; for (i = 0; i < prcm_irq_setup->nr_irqs; i++) if (!strcmp(prcm_irq_setup->irqs[i].name, name)) return prcm_irq_setup->base_irq + prcm_irq_setup->irqs[i].offset; return -ENOENT; } /** * omap_prcm_irq_cleanup - reverses memory allocated and other steps * done by omap_prcm_register_chain_handler() * * No return value. */ void omap_prcm_irq_cleanup(void) { int i; if (!prcm_irq_setup) { pr_err("PRCM: IRQ handler not initialized; cannot cleanup\n"); return; } if (prcm_irq_chips) { for (i = 0; i < prcm_irq_setup->nr_regs; i++) { if (prcm_irq_chips[i]) irq_remove_generic_chip(prcm_irq_chips[i], 0xffffffff, 0, 0); prcm_irq_chips[i] = NULL; } kfree(prcm_irq_chips); prcm_irq_chips = NULL; } kfree(prcm_irq_setup->saved_mask); prcm_irq_setup->saved_mask = NULL; kfree(prcm_irq_setup->priority_mask); prcm_irq_setup->priority_mask = NULL; irq_set_chained_handler(prcm_irq_setup->irq, NULL); if (prcm_irq_setup->base_irq > 0) irq_free_descs(prcm_irq_setup->base_irq, prcm_irq_setup->nr_regs * 32); prcm_irq_setup->base_irq = 0; } void omap_prcm_irq_prepare(void) { prcm_irq_setup->suspended = true; } void omap_prcm_irq_complete(void) { prcm_irq_setup->suspended = false; /* If we have not saved the masks, do not attempt to restore */ if (!prcm_irq_setup->suspend_save_flag) return; prcm_irq_setup->suspend_save_flag = false; /* * Re-enable all masked PRCM irq sources, this causes the PRCM * interrupt to fire immediately if the events were masked * previously in the chain handler */ prcm_irq_setup->restore_irqen(prcm_irq_setup->saved_mask); } /** * omap_prcm_register_chain_handler - initializes the prcm chained interrupt * handler based on provided parameters * @irq_setup: hardware data about the underlying PRM/PRCM * * Set up the PRCM chained interrupt handler on the PRCM IRQ. Sets up * one generic IRQ chip per PRM interrupt status/enable register pair. * Returns 0 upon success, -EINVAL if called twice or if invalid * arguments are passed, or -ENOMEM on any other error. */ int omap_prcm_register_chain_handler(struct omap_prcm_irq_setup *irq_setup) { int nr_regs = irq_setup->nr_regs; u32 mask[OMAP_PRCM_MAX_NR_PENDING_REG]; int offset, i; struct irq_chip_generic *gc; struct irq_chip_type *ct; if (!irq_setup) return -EINVAL; if (prcm_irq_setup) { pr_err("PRCM: already initialized; won't reinitialize\n"); return -EINVAL; } if (nr_regs > OMAP_PRCM_MAX_NR_PENDING_REG) { pr_err("PRCM: nr_regs too large\n"); return -EINVAL; } prcm_irq_setup = irq_setup; prcm_irq_chips = kzalloc(sizeof(void *) * nr_regs, GFP_KERNEL); prcm_irq_setup->saved_mask = kzalloc(sizeof(u32) * nr_regs, GFP_KERNEL); prcm_irq_setup->priority_mask = kzalloc(sizeof(u32) * nr_regs, GFP_KERNEL); if (!prcm_irq_chips || !prcm_irq_setup->saved_mask || !prcm_irq_setup->priority_mask) { pr_err("PRCM: kzalloc failed\n"); goto err; } memset(mask, 0, sizeof(mask)); for (i = 0; i < irq_setup->nr_irqs; i++) { offset = irq_setup->irqs[i].offset; mask[offset >> 5] |= 1 << (offset & 0x1f); if (irq_setup->irqs[i].priority) irq_setup->priority_mask[offset >> 5] |= 1 << (offset & 0x1f); } irq_set_chained_handler(irq_setup->irq, omap_prcm_irq_handler); irq_setup->base_irq = irq_alloc_descs(-1, 0, irq_setup->nr_regs * 32, 0); if (irq_setup->base_irq < 0) { pr_err("PRCM: failed to allocate irq descs: %d\n", irq_setup->base_irq); goto err; } for (i = 0; i < irq_setup->nr_regs; i++) { gc = irq_alloc_generic_chip("PRCM", 1, irq_setup->base_irq + i * 32, prm_base, handle_level_irq); if (!gc) { pr_err("PRCM: failed to allocate generic chip\n"); goto err; } ct = gc->chip_types; ct->chip.irq_ack = irq_gc_ack_set_bit; ct->chip.irq_mask = irq_gc_mask_clr_bit; ct->chip.irq_unmask = irq_gc_mask_set_bit; ct->regs.ack = irq_setup->ack + i * 4; ct->regs.mask = irq_setup->mask + i * 4; irq_setup_generic_chip(gc, mask[i], 0, IRQ_NOREQUEST, 0); prcm_irq_chips[i] = gc; } return 0; err: omap_prcm_irq_cleanup(); return -ENOMEM; }