ARM: at91: add AIC5 support

The number of lines of AIC5 has increased from 32 to 128. Due to this
increase, a source select register has been introduced for the interrupt
line selection. Moreover, register mapping has been changed. For that reasons,
we need some dedicated callbacks for AIC5.
Power management is also concerned by these changes. On suspend, we can't get
the whole interrupt mask register as before, we have to read this register 128
times. To reduce this overhead, a snapshot of the whole IMR is maintained.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

1 files changed, 286 insertions, 57 deletions

diff --git a/arch/arm/mach-at91/irq.c b/arch/arm/mach-at91/irq.c
index 75ca2f44c78e..c5eaaa060bd8 100644
--- a/arch/arm/mach-at91/irq.c
+++ b/arch/arm/mach-at91/irq.c
@@ -23,6 +23,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/mm.h>
+#include <linux/bitmap.h>
 #include <linux/types.h>
 #include <linux/irq.h>
 #include <linux/of.h>
@@ -46,9 +47,116 @@
 void __iomem *at91_aic_base;
 static struct irq_domain *at91_aic_domain;
 static struct device_node *at91_aic_np;
+static unsigned int n_irqs = NR_AIC_IRQS;
+static unsigned long at91_aic_caps = 0;
 static unsigned int *at91_aic_irq_priorities;
 
-asmlinkage void __exception_irq_entry at91_aic_handle_irq(struct pt_regs *regs)
+/* AIC5 introduces a Source Select Register */
+#define AT91_AIC_CAP_AIC5	(1 << 0)
+#define has_aic5()		(at91_aic_caps & AT91_AIC_CAP_AIC5)
+
+#ifdef CONFIG_PM
+
+static unsigned long *wakeups;
+static unsigned long *backups;
+
+#define set_backup(bit) set_bit(bit, backups)
+#define clear_backup(bit) clear_bit(bit, backups)
+
+static int at91_aic_pm_init(void)
+{
+	backups = kzalloc(BITS_TO_LONGS(n_irqs) * sizeof(*backups), GFP_KERNEL);
+	if (!backups)
+		return -ENOMEM;
+
+	wakeups = kzalloc(BITS_TO_LONGS(n_irqs) * sizeof(*backups), GFP_KERNEL);
+	if (!wakeups) {
+		kfree(backups);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int at91_aic_set_wake(struct irq_data *d, unsigned value)
+{
+	if (unlikely(d->hwirq >= n_irqs))
+		return -EINVAL;
+
+	if (value)
+		set_bit(d->hwirq, wakeups);
+	else
+		clear_bit(d->hwirq, wakeups);
+
+	return 0;
+}
+
+void at91_irq_suspend(void)
+{
+	int i = 0, bit;
+
+	if (has_aic5()) {
+		/* disable enabled irqs */
+		while ((bit = find_next_bit(backups, n_irqs, i)) < n_irqs) {
+			at91_aic_write(AT91_AIC5_SSR,
+				       bit & AT91_AIC5_INTSEL_MSK);
+			at91_aic_write(AT91_AIC5_IDCR, 1);
+			i = bit;
+		}
+		/* enable wakeup irqs */
+		i = 0;
+		while ((bit = find_next_bit(wakeups, n_irqs, i)) < n_irqs) {
+			at91_aic_write(AT91_AIC5_SSR,
+				       bit & AT91_AIC5_INTSEL_MSK);
+			at91_aic_write(AT91_AIC5_IECR, 1);
+			i = bit;
+		}
+	} else {
+		at91_aic_write(AT91_AIC_IDCR, *backups);
+		at91_aic_write(AT91_AIC_IECR, *wakeups);
+	}
+}
+
+void at91_irq_resume(void)
+{
+	int i = 0, bit;
+
+	if (has_aic5()) {
+		/* disable wakeup irqs */
+		while ((bit = find_next_bit(wakeups, n_irqs, i)) < n_irqs) {
+			at91_aic_write(AT91_AIC5_SSR,
+				       bit & AT91_AIC5_INTSEL_MSK);
+			at91_aic_write(AT91_AIC5_IDCR, 1);
+			i = bit;
+		}
+		/* enable irqs disabled for suspend */
+		i = 0;
+		while ((bit = find_next_bit(backups, n_irqs, i)) < n_irqs) {
+			at91_aic_write(AT91_AIC5_SSR,
+				       bit & AT91_AIC5_INTSEL_MSK);
+			at91_aic_write(AT91_AIC5_IECR, 1);
+			i = bit;
+		}
+	} else {
+		at91_aic_write(AT91_AIC_IDCR, *wakeups);
+		at91_aic_write(AT91_AIC_IECR, *backups);
+	}
+}
+
+#else
+static inline int at91_aic_pm_init(void)
+{
+	return 0;
+}
+
+#define set_backup(bit)
+#define clear_backup(bit)
+#define at91_aic_set_wake	NULL
+
+#endif /* CONFIG_PM */
+
+asmlinkage void __exception_irq_entry
+at91_aic_handle_irq(struct pt_regs *regs)
 {
 	u32 irqnr;
 	u32 irqstat;
@@ -66,16 +174,53 @@ asmlinkage void __exception_irq_entry at91_aic_handle_irq(struct pt_regs *regs)
 		handle_IRQ(irqnr, regs);
 }
 
+asmlinkage void __exception_irq_entry
+at91_aic5_handle_irq(struct pt_regs *regs)
+{
+	u32 irqnr;
+	u32 irqstat;
+
+	irqnr = at91_aic_read(AT91_AIC5_IVR);
+	irqstat = at91_aic_read(AT91_AIC5_ISR);
+
+	if (!irqstat)
+		at91_aic_write(AT91_AIC5_EOICR, 0);
+	else
+		handle_IRQ(irqnr, regs);
+}
+
 static void at91_aic_mask_irq(struct irq_data *d)
 {
 	/* Disable interrupt on AIC */
 	at91_aic_write(AT91_AIC_IDCR, 1 << d->hwirq);
+	/* Update ISR cache */
+	clear_backup(d->hwirq);
+}
+
+static void __maybe_unused at91_aic5_mask_irq(struct irq_data *d)
+{
+	/* Disable interrupt on AIC5 */
+	at91_aic_write(AT91_AIC5_SSR, d->hwirq & AT91_AIC5_INTSEL_MSK);
+	at91_aic_write(AT91_AIC5_IDCR, 1);
+	/* Update ISR cache */
+	clear_backup(d->hwirq);
 }
 
 static void at91_aic_unmask_irq(struct irq_data *d)
 {
 	/* Enable interrupt on AIC */
 	at91_aic_write(AT91_AIC_IECR, 1 << d->hwirq);
+	/* Update ISR cache */
+	set_backup(d->hwirq);
+}
+
+static void __maybe_unused at91_aic5_unmask_irq(struct irq_data *d)
+{
+	/* Enable interrupt on AIC5 */
+	at91_aic_write(AT91_AIC5_SSR, d->hwirq & AT91_AIC5_INTSEL_MSK);
+	at91_aic_write(AT91_AIC5_IECR, 1);
+	/* Update ISR cache */
+	set_backup(d->hwirq);
 }
 
 static void at91_aic_eoi(struct irq_data *d)
@@ -87,13 +232,18 @@ static void at91_aic_eoi(struct irq_data *d)
 	at91_aic_write(AT91_AIC_EOICR, 0);
 }
 
-unsigned int at91_extern_irq;
+static void __maybe_unused at91_aic5_eoi(struct irq_data *d)
+{
+	at91_aic_write(AT91_AIC5_EOICR, 0);
+}
 
-#define is_extern_irq(hwirq) ((1 << (hwirq)) & at91_extern_irq)
+unsigned long *at91_extern_irq;
 
-static int at91_aic_set_type(struct irq_data *d, unsigned type)
+#define is_extern_irq(hwirq) test_bit(hwirq, at91_extern_irq)
+
+static int at91_aic_compute_srctype(struct irq_data *d, unsigned type)
 {
-	unsigned int smr, srctype;
+	int srctype;
 
 	switch (type) {
 	case IRQ_TYPE_LEVEL_HIGH:
@@ -106,58 +256,44 @@ static int at91_aic_set_type(struct irq_data *d, unsigned type)
 		if ((d->hwirq == AT91_ID_FIQ) || is_extern_irq(d->hwirq))		/* only supported on external interrupts */
 			srctype = AT91_AIC_SRCTYPE_LOW;
 		else
-			return -EINVAL;
+			srctype = -EINVAL;
 		break;
 	case IRQ_TYPE_EDGE_FALLING:
 		if ((d->hwirq == AT91_ID_FIQ) || is_extern_irq(d->hwirq))		/* only supported on external interrupts */
 			srctype = AT91_AIC_SRCTYPE_FALLING;
 		else
-			return -EINVAL;
+			srctype = -EINVAL;
 		break;
 	default:
-		return -EINVAL;
+		srctype = -EINVAL;
 	}
 
-	smr = at91_aic_read(AT91_AIC_SMR(d->hwirq)) & ~AT91_AIC_SRCTYPE;
-	at91_aic_write(AT91_AIC_SMR(d->hwirq), smr | srctype);
-	return 0;
+	return srctype;
 }
 
-#ifdef CONFIG_PM
-
-static u32 wakeups;
-static u32 backups;
-
-static int at91_aic_set_wake(struct irq_data *d, unsigned value)
+static int at91_aic_set_type(struct irq_data *d, unsigned type)
 {
-	if (unlikely(d->hwirq >= NR_AIC_IRQS))
-		return -EINVAL;
-
-	if (value)
-		wakeups |= (1 << d->hwirq);
-	else
-		wakeups &= ~(1 << d->hwirq);
+	unsigned int smr;
+	int srctype;
+
+	srctype = at91_aic_compute_srctype(d, type);
+	if (srctype < 0)
+		return srctype;
+
+	if (has_aic5()) {
+		at91_aic_write(AT91_AIC5_SSR,
+			       d->hwirq & AT91_AIC5_INTSEL_MSK);
+		smr = at91_aic_read(AT91_AIC5_SMR) & ~AT91_AIC_SRCTYPE;
+		at91_aic_write(AT91_AIC5_SMR, smr | srctype);
+	} else {
+		smr = at91_aic_read(AT91_AIC_SMR(d->hwirq))
+		      & ~AT91_AIC_SRCTYPE;
+		at91_aic_write(AT91_AIC_SMR(d->hwirq), smr | srctype);
+	}
 
 	return 0;
 }
 
-void at91_irq_suspend(void)
-{
-	backups = at91_aic_read(AT91_AIC_IMR);
-	at91_aic_write(AT91_AIC_IDCR, backups);
-	at91_aic_write(AT91_AIC_IECR, wakeups);
-}
-
-void at91_irq_resume(void)
-{
-	at91_aic_write(AT91_AIC_IDCR, wakeups);
-	at91_aic_write(AT91_AIC_IECR, backups);
-}
-
-#else
-#define at91_aic_set_wake	NULL
-#endif
-
 static struct irq_chip at91_aic_chip = {
 	.name		= "AIC",
 	.irq_mask	= at91_aic_mask_irq,
@@ -193,6 +329,35 @@ static void __init at91_aic_hw_init(unsigned int spu_vector)
 	at91_aic_write(AT91_AIC_ICCR, 0xFFFFFFFF);
 }
 
+static void __init __maybe_unused at91_aic5_hw_init(unsigned int spu_vector)
+{
+	int i;
+
+	/*
+	 * Perform 8 End Of Interrupt Command to make sure AIC
+	 * will not Lock out nIRQ
+	 */
+	for (i = 0; i < 8; i++)
+		at91_aic_write(AT91_AIC5_EOICR, 0);
+
+	/*
+	 * Spurious Interrupt ID in Spurious Vector Register.
+	 * When there is no current interrupt, the IRQ Vector Register
+	 * reads the value stored in AIC_SPU
+	 */
+	at91_aic_write(AT91_AIC5_SPU, spu_vector);
+
+	/* No debugging in AIC: Debug (Protect) Control Register */
+	at91_aic_write(AT91_AIC5_DCR, 0);
+
+	/* Disable and clear all interrupts initially */
+	for (i = 0; i < n_irqs; i++) {
+		at91_aic_write(AT91_AIC5_SSR, i & AT91_AIC5_INTSEL_MSK);
+		at91_aic_write(AT91_AIC5_IDCR, 1);
+		at91_aic_write(AT91_AIC5_ICCR, 1);
+	}
+}
+
 #if defined(CONFIG_OF)
 static int at91_aic_irq_map(struct irq_domain *h, unsigned int virq,
 							irq_hw_number_t hw)
@@ -210,13 +375,31 @@ static int at91_aic_irq_map(struct irq_domain *h, unsigned int virq,
 	return 0;
 }
 
+static int at91_aic5_irq_map(struct irq_domain *h, unsigned int virq,
+		irq_hw_number_t hw)
+{
+	at91_aic_write(AT91_AIC5_SSR, hw & AT91_AIC5_INTSEL_MSK);
+
+	/* Put virq number in Source Vector Register */
+	at91_aic_write(AT91_AIC5_SVR, virq);
+
+	/* Active Low interrupt, with priority */
+	at91_aic_write(AT91_AIC5_SMR,
+		       AT91_AIC_SRCTYPE_LOW | at91_aic_irq_priorities[hw]);
+
+	irq_set_chip_and_handler(virq, &at91_aic_chip, handle_fasteoi_irq);
+	set_irq_flags(virq, IRQF_VALID | IRQF_PROBE);
+
+	return 0;
+}
+
 static int at91_aic_irq_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
 				const u32 *intspec, unsigned int intsize,
 				irq_hw_number_t *out_hwirq, unsigned int *out_type)
 {
 	if (WARN_ON(intsize < 3))
 		return -EINVAL;
-	if (WARN_ON(intspec[0] >= NR_AIC_IRQS))
+	if (WARN_ON(intspec[0] >= n_irqs))
 		return -EINVAL;
 	if (WARN_ON((intspec[2] < AT91_AIC_IRQ_MIN_PRIORITY)
 		    || (intspec[2] > AT91_AIC_IRQ_MAX_PRIORITY)))
@@ -234,14 +417,24 @@ static struct irq_domain_ops at91_aic_irq_ops = {
 	.xlate	= at91_aic_irq_domain_xlate,
 };
 
-int __init at91_aic_of_init(struct device_node *node,
-				     struct device_node *parent)
+int __init at91_aic_of_common_init(struct device_node *node,
+				    struct device_node *parent)
 {
 	struct property *prop;
 	const __be32 *p;
 	u32 val;
 
-	at91_aic_irq_priorities = kzalloc(NR_AIC_IRQS
+	at91_extern_irq = kzalloc(BITS_TO_LONGS(n_irqs)
+				  * sizeof(*at91_extern_irq), GFP_KERNEL);
+	if (!at91_extern_irq)
+		return -ENOMEM;
+
+	if (at91_aic_pm_init()) {
+		kfree(at91_extern_irq);
+		return -ENOMEM;
+	}
+
+	at91_aic_irq_priorities = kzalloc(n_irqs
 					  * sizeof(*at91_aic_irq_priorities),
 					  GFP_KERNEL);
 	if (!at91_aic_irq_priorities)
@@ -250,22 +443,56 @@ int __init at91_aic_of_init(struct device_node *node,
 	at91_aic_base = of_iomap(node, 0);
 	at91_aic_np = node;
 
-	at91_aic_domain = irq_domain_add_linear(at91_aic_np, NR_AIC_IRQS,
+	at91_aic_domain = irq_domain_add_linear(at91_aic_np, n_irqs,
 						&at91_aic_irq_ops, NULL);
 	if (!at91_aic_domain)
 		panic("Unable to add AIC irq domain (DT)\n");
 
-	at91_extern_irq = 0;
 	of_property_for_each_u32(node, "atmel,external-irqs", prop, p, val) {
-		if (val > 31)
-			pr_warn("AIC: external irq %d > 31 skip it\n", val);
+		if (val >= n_irqs)
+			pr_warn("AIC: external irq %d >= %d skip it\n",
+				val, n_irqs);
 		else
-			at91_extern_irq |= (1 << val);
+			set_bit(val, at91_extern_irq);
 	}
 
 	irq_set_default_host(at91_aic_domain);
 
-	at91_aic_hw_init(NR_AIC_IRQS);
+	return 0;
+}
+
+int __init at91_aic_of_init(struct device_node *node,
+				     struct device_node *parent)
+{
+	int err;
+
+	err = at91_aic_of_common_init(node, parent);
+	if (err)
+		return err;
+
+	at91_aic_hw_init(n_irqs);
+
+	return 0;
+}
+
+int __init at91_aic5_of_init(struct device_node *node,
+				     struct device_node *parent)
+{
+	int err;
+
+	at91_aic_caps |= AT91_AIC_CAP_AIC5;
+	n_irqs = NR_AIC5_IRQS;
+	at91_aic_chip.irq_ack           = at91_aic5_mask_irq;
+	at91_aic_chip.irq_mask		= at91_aic5_mask_irq;
+	at91_aic_chip.irq_unmask	= at91_aic5_unmask_irq;
+	at91_aic_chip.irq_eoi		= at91_aic5_eoi;
+	at91_aic_irq_ops.map		= at91_aic5_irq_map;
+
+	err = at91_aic_of_common_init(node, parent);
+	if (err)
+		return err;
+
+	at91_aic5_hw_init(n_irqs);
 
 	return 0;
 }
@@ -274,22 +501,25 @@ int __init at91_aic_of_init(struct device_node *node,
 /*
  * Initialize the AIC interrupt controller.
  */
-void __init at91_aic_init(unsigned int priority[NR_AIC_IRQS])
+void __init at91_aic_init(unsigned int *priority)
 {
 	unsigned int i;
 	int irq_base;
 
+	if (at91_aic_pm_init())
+		panic("Unable to allocate bit maps\n");
+
 	at91_aic_base = ioremap(AT91_AIC, 512);
 	if (!at91_aic_base)
 		panic("Unable to ioremap AIC registers\n");
 
 	/* Add irq domain for AIC */
-	irq_base = irq_alloc_descs(-1, 0, NR_AIC_IRQS, 0);
+	irq_base = irq_alloc_descs(-1, 0, n_irqs, 0);
 	if (irq_base < 0) {
 		WARN(1, "Cannot allocate irq_descs, assuming pre-allocated\n");
 		irq_base = 0;
 	}
-	at91_aic_domain = irq_domain_add_legacy(at91_aic_np, NR_AIC_IRQS,
+	at91_aic_domain = irq_domain_add_legacy(at91_aic_np, n_irqs,
 						irq_base, 0,
 						&irq_domain_simple_ops, NULL);
 
@@ -302,15 +532,14 @@ void __init at91_aic_init(unsigned int priority[NR_AIC_IRQS])
 	 * The IVR is used by macro get_irqnr_and_base to read and verify.
 	 * The irq number is NR_AIC_IRQS when a spurious interrupt has occurred.
 	 */
-	for (i = 0; i < NR_AIC_IRQS; i++) {
+	for (i = 0; i < n_irqs; i++) {
 		/* Put hardware irq number in Source Vector Register: */
 		at91_aic_write(AT91_AIC_SVR(i), NR_IRQS_LEGACY + i);
 		/* Active Low interrupt, with the specified priority */
 		at91_aic_write(AT91_AIC_SMR(i), AT91_AIC_SRCTYPE_LOW | priority[i]);
-
 		irq_set_chip_and_handler(NR_IRQS_LEGACY + i, &at91_aic_chip, handle_fasteoi_irq);
 		set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
 	}
 
-	at91_aic_hw_init(NR_AIC_IRQS);
+	at91_aic_hw_init(n_irqs);
 }