1 files changed, 319 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/prm_common.c b/arch/arm/mach-omap2/prm_common.c
new file mode 100644
index 00000000..d28f8488
--- /dev/null
+++ b/arch/arm/mach-omap2/prm_common.c
@@ -0,0 +1,319 @@
+/*
+ * 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;
+}