irqchip/stm32: Add multi-bank management

-Prepare to manage multi-bank of external interrupts
(N banks of 32 inputs).
-Prepare to manage registers offsets by compatible
(registers offsets could be different follow per stm32 platform).

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/drivers/irqchip/irq-stm32-exti.c b/drivers/irqchip/irq-stm32-exti.c
index 45363ff..ef37870 100644 (file)
--- a/drivers/irqchip/irq-stm32-exti.c
+++ b/drivers/irqchip/irq-stm32-exti.c
@@ -14,27 +14,66 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 
-#define EXTI_IMR       0x0
-#define EXTI_EMR       0x4
-#define EXTI_RTSR      0x8
-#define EXTI_FTSR      0xc
-#define EXTI_SWIER     0x10
-#define EXTI_PR                0x14
+#define IRQS_PER_BANK 32
+
+struct stm32_exti_bank {
+       u32 imr_ofst;
+       u32 emr_ofst;
+       u32 rtsr_ofst;
+       u32 ftsr_ofst;
+       u32 swier_ofst;
+       u32 pr_ofst;
+};
+
+static const struct stm32_exti_bank stm32f4xx_exti_b1 = {
+       .imr_ofst       = 0x00,
+       .emr_ofst       = 0x04,
+       .rtsr_ofst      = 0x08,
+       .ftsr_ofst      = 0x0C,
+       .swier_ofst     = 0x10,
+       .pr_ofst        = 0x14,
+};
+
+static const struct stm32_exti_bank *stm32f4xx_exti_banks[] = {
+       &stm32f4xx_exti_b1,
+};
+
+static unsigned long stm32_exti_pending(struct irq_chip_generic *gc)
+{
+       const struct stm32_exti_bank *stm32_bank = gc->private;
+
+       return irq_reg_readl(gc, stm32_bank->pr_ofst);
+}
+
+static void stm32_exti_irq_ack(struct irq_chip_generic *gc, u32 mask)
+{
+       const struct stm32_exti_bank *stm32_bank = gc->private;
+
+       irq_reg_writel(gc, mask, stm32_bank->pr_ofst);
+}
 
 static void stm32_irq_handler(struct irq_desc *desc)
 {
        struct irq_domain *domain = irq_desc_get_handler_data(desc);
-       struct irq_chip_generic *gc = domain->gc->gc[0];
        struct irq_chip *chip = irq_desc_get_chip(desc);
+       unsigned int virq, nbanks = domain->gc->num_chips;
+       struct irq_chip_generic *gc;
+       const struct stm32_exti_bank *stm32_bank;
        unsigned long pending;
-       int n;
+       int n, i, irq_base = 0;
 
        chained_irq_enter(chip, desc);
 
-       while ((pending = irq_reg_readl(gc, EXTI_PR))) {
-               for_each_set_bit(n, &pending, BITS_PER_LONG) {
-                       generic_handle_irq(irq_find_mapping(domain, n));
-                       irq_reg_writel(gc, BIT(n), EXTI_PR);
+       for (i = 0; i < nbanks; i++, irq_base += IRQS_PER_BANK) {
+               gc = irq_get_domain_generic_chip(domain, irq_base);
+               stm32_bank = gc->private;
+
+               while ((pending = stm32_exti_pending(gc))) {
+                       for_each_set_bit(n, &pending, IRQS_PER_BANK) {
+                               virq = irq_find_mapping(domain, irq_base + n);
+                               generic_handle_irq(virq);
+                               stm32_exti_irq_ack(gc, BIT(n));
+                       }
                }
        }
 
@@ -44,13 +83,14 @@ static void stm32_irq_handler(struct irq_desc *desc)
 static int stm32_irq_set_type(struct irq_data *data, unsigned int type)
 {
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
-       int pin = data->hwirq;
+       const struct stm32_exti_bank *stm32_bank = gc->private;
+       int pin = data->hwirq % IRQS_PER_BANK;
        u32 rtsr, ftsr;
 
        irq_gc_lock(gc);
 
-       rtsr = irq_reg_readl(gc, EXTI_RTSR);
-       ftsr = irq_reg_readl(gc, EXTI_FTSR);
+       rtsr = irq_reg_readl(gc, stm32_bank->rtsr_ofst);
+       ftsr = irq_reg_readl(gc, stm32_bank->ftsr_ofst);
 
        switch (type) {
        case IRQ_TYPE_EDGE_RISING:
@@ -70,8 +110,8 @@ static int stm32_irq_set_type(struct irq_data *data, unsigned int type)
                return -EINVAL;
        }
 
-       irq_reg_writel(gc, rtsr, EXTI_RTSR);
-       irq_reg_writel(gc, ftsr, EXTI_FTSR);
+       irq_reg_writel(gc, rtsr, stm32_bank->rtsr_ofst);
+       irq_reg_writel(gc, ftsr, stm32_bank->ftsr_ofst);
 
        irq_gc_unlock(gc);
 
@@ -81,17 +121,18 @@ static int stm32_irq_set_type(struct irq_data *data, unsigned int type)
 static int stm32_irq_set_wake(struct irq_data *data, unsigned int on)
 {
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
-       int pin = data->hwirq;
+       const struct stm32_exti_bank *stm32_bank = gc->private;
+       int pin = data->hwirq % IRQS_PER_BANK;
        u32 emr;
 
        irq_gc_lock(gc);
 
-       emr = irq_reg_readl(gc, EXTI_EMR);
+       emr = irq_reg_readl(gc, stm32_bank->emr_ofst);
        if (on)
                emr |= BIT(pin);
        else
                emr &= ~BIT(pin);
-       irq_reg_writel(gc, emr, EXTI_EMR);
+       irq_reg_writel(gc, emr, stm32_bank->emr_ofst);
 
        irq_gc_unlock(gc);
 
@@ -101,11 +142,12 @@ static int stm32_irq_set_wake(struct irq_data *data, unsigned int on)
 static int stm32_exti_alloc(struct irq_domain *d, unsigned int virq,
                            unsigned int nr_irqs, void *data)
 {
-       struct irq_chip_generic *gc = d->gc->gc[0];
+       struct irq_chip_generic *gc;
        struct irq_fwspec *fwspec = data;
        irq_hw_number_t hwirq;
 
        hwirq = fwspec->param[0];
+       gc = irq_get_domain_generic_chip(d, hwirq);
 
        irq_map_generic_chip(d, virq, hwirq);
        irq_domain_set_info(d, virq, hwirq, &gc->chip_types->chip, gc,
@@ -129,8 +171,9 @@ struct irq_domain_ops irq_exti_domain_ops = {
        .free   = stm32_exti_free,
 };
 
-static int __init stm32_exti_init(struct device_node *node,
-                                 struct device_node *parent)
+static int
+__init stm32_exti_init(const struct stm32_exti_bank **stm32_exti_banks,
+                      int bank_nr, struct device_node *node)
 {
        unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
        int nr_irqs, nr_exti, ret, i;
@@ -144,23 +187,16 @@ static int __init stm32_exti_init(struct device_node *node,
                return -ENOMEM;
        }
 
-       /* Determine number of irqs supported */
-       writel_relaxed(~0UL, base + EXTI_RTSR);
-       nr_exti = fls(readl_relaxed(base + EXTI_RTSR));
-       writel_relaxed(0, base + EXTI_RTSR);
-
-       pr_info("%pOF: %d External IRQs detected\n", node, nr_exti);
-
-       domain = irq_domain_add_linear(node, nr_exti,
+       domain = irq_domain_add_linear(node, bank_nr * IRQS_PER_BANK,
                                       &irq_exti_domain_ops, NULL);
        if (!domain) {
                pr_err("%s: Could not register interrupt domain.\n",
-                               node->name);
+                      node->name);
                ret = -ENOMEM;
                goto out_unmap;
        }
 
-       ret = irq_alloc_domain_generic_chips(domain, nr_exti, 1, "exti",
+       ret = irq_alloc_domain_generic_chips(domain, IRQS_PER_BANK, 1, "exti",
                                             handle_edge_irq, clr, 0, 0);
        if (ret) {
                pr_err("%pOF: Could not allocate generic interrupt chip.\n",
@@ -168,18 +204,32 @@ static int __init stm32_exti_init(struct device_node *node,
                goto out_free_domain;
        }
 
-       gc = domain->gc->gc[0];
-       gc->reg_base                         = base;
-       gc->chip_types->type               = IRQ_TYPE_EDGE_BOTH;
-       gc->chip_types->chip.name          = gc->chip_types[0].chip.name;
-       gc->chip_types->chip.irq_ack       = irq_gc_ack_set_bit;
-       gc->chip_types->chip.irq_mask      = irq_gc_mask_clr_bit;
-       gc->chip_types->chip.irq_unmask    = irq_gc_mask_set_bit;
-       gc->chip_types->chip.irq_set_type  = stm32_irq_set_type;
-       gc->chip_types->chip.irq_set_wake  = stm32_irq_set_wake;
-       gc->chip_types->regs.ack           = EXTI_PR;
-       gc->chip_types->regs.mask          = EXTI_IMR;
-       gc->chip_types->handler            = handle_edge_irq;
+       for (i = 0; i < bank_nr; i++) {
+               const struct stm32_exti_bank *stm32_bank = stm32_exti_banks[i];
+               u32 irqs_mask;
+
+               gc = irq_get_domain_generic_chip(domain, i * IRQS_PER_BANK);
+
+               gc->reg_base = base;
+               gc->chip_types->type = IRQ_TYPE_EDGE_BOTH;
+               gc->chip_types->chip.irq_ack = irq_gc_ack_set_bit;
+               gc->chip_types->chip.irq_mask = irq_gc_mask_clr_bit;
+               gc->chip_types->chip.irq_unmask = irq_gc_mask_set_bit;
+               gc->chip_types->chip.irq_set_type = stm32_irq_set_type;
+               gc->chip_types->chip.irq_set_wake = stm32_irq_set_wake;
+               gc->chip_types->regs.ack = stm32_bank->pr_ofst;
+               gc->chip_types->regs.mask = stm32_bank->imr_ofst;
+               gc->private = (void *)stm32_bank;
+
+               /* Determine number of irqs supported */
+               writel_relaxed(~0UL, base + stm32_bank->rtsr_ofst);
+               irqs_mask = readl_relaxed(base + stm32_bank->rtsr_ofst);
+               nr_exti = fls(readl_relaxed(base + stm32_bank->rtsr_ofst));
+               writel_relaxed(0, base + stm32_bank->rtsr_ofst);
+
+               pr_info("%s: bank%d, External IRQs available:%#x\n",
+                       node->full_name, i, irqs_mask);
+       }
 
        nr_irqs = of_irq_count(node);
        for (i = 0; i < nr_irqs; i++) {
@@ -198,4 +248,11 @@ out_unmap:
        return ret;
 }
 
-IRQCHIP_DECLARE(stm32_exti, "st,stm32-exti", stm32_exti_init);
+static int __init stm32f4_exti_of_init(struct device_node *np,
+                                      struct device_node *parent)
+{
+       return stm32_exti_init(stm32f4xx_exti_banks,
+                       ARRAY_SIZE(stm32f4xx_exti_banks), np);
+}
+
+IRQCHIP_DECLARE(stm32f4_exti, "st,stm32-exti", stm32f4_exti_of_init);