1 files changed, 412 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-stm32-exti.c b/drivers/irqchip/irq-stm32-exti.c
new file mode 100644
index 000000000000..978811f2abe8
--- /dev/null
+++ b/drivers/irqchip/irq-stm32-exti.c
@@ -0,0 +1,412 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) Maxime Coquelin 2015
+ * Copyright (C) STMicroelectronics 2017-2024
+ * Author:  Maxime Coquelin <mcoquelin.stm32@gmail.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+#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 rpr_ofst;
+};
+
+struct stm32_exti_drv_data {
+	const struct stm32_exti_bank **exti_banks;
+	const u8 *desc_irqs;
+	u32 bank_nr;
+};
+
+struct stm32_exti_chip_data {
+	struct stm32_exti_host_data *host_data;
+	const struct stm32_exti_bank *reg_bank;
+	u32 wake_active;
+	u32 mask_cache;
+	u32 rtsr_cache;
+	u32 ftsr_cache;
+	u32 event_reserved;
+};
+
+struct stm32_exti_host_data {
+	void __iomem *base;
+	struct device *dev;
+	struct stm32_exti_chip_data *chips_data;
+	const struct stm32_exti_drv_data *drv_data;
+};
+
+static const struct stm32_exti_bank stm32f4xx_exti_b1 = {
+	.imr_ofst	= 0x00,
+	.emr_ofst	= 0x04,
+	.rtsr_ofst	= 0x08,
+	.ftsr_ofst	= 0x0C,
+	.swier_ofst	= 0x10,
+	.rpr_ofst	= 0x14,
+};
+
+static const struct stm32_exti_bank *stm32f4xx_exti_banks[] = {
+	&stm32f4xx_exti_b1,
+};
+
+static const struct stm32_exti_drv_data stm32f4xx_drv_data = {
+	.exti_banks = stm32f4xx_exti_banks,
+	.bank_nr = ARRAY_SIZE(stm32f4xx_exti_banks),
+};
+
+static const struct stm32_exti_bank stm32h7xx_exti_b1 = {
+	.imr_ofst	= 0x80,
+	.emr_ofst	= 0x84,
+	.rtsr_ofst	= 0x00,
+	.ftsr_ofst	= 0x04,
+	.swier_ofst	= 0x08,
+	.rpr_ofst	= 0x88,
+};
+
+static const struct stm32_exti_bank stm32h7xx_exti_b2 = {
+	.imr_ofst	= 0x90,
+	.emr_ofst	= 0x94,
+	.rtsr_ofst	= 0x20,
+	.ftsr_ofst	= 0x24,
+	.swier_ofst	= 0x28,
+	.rpr_ofst	= 0x98,
+};
+
+static const struct stm32_exti_bank stm32h7xx_exti_b3 = {
+	.imr_ofst	= 0xA0,
+	.emr_ofst	= 0xA4,
+	.rtsr_ofst	= 0x40,
+	.ftsr_ofst	= 0x44,
+	.swier_ofst	= 0x48,
+	.rpr_ofst	= 0xA8,
+};
+
+static const struct stm32_exti_bank *stm32h7xx_exti_banks[] = {
+	&stm32h7xx_exti_b1,
+	&stm32h7xx_exti_b2,
+	&stm32h7xx_exti_b3,
+};
+
+static const struct stm32_exti_drv_data stm32h7xx_drv_data = {
+	.exti_banks = stm32h7xx_exti_banks,
+	.bank_nr = ARRAY_SIZE(stm32h7xx_exti_banks),
+};
+
+static unsigned long stm32_exti_pending(struct irq_chip_generic *gc)
+{
+	struct stm32_exti_chip_data *chip_data = gc->private;
+	const struct stm32_exti_bank *stm32_bank = chip_data->reg_bank;
+
+	return irq_reg_readl(gc, stm32_bank->rpr_ofst);
+}
+
+static void stm32_irq_handler(struct irq_desc *desc)
+{
+	struct irq_domain *domain = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned int nbanks = domain->gc->num_chips;
+	struct irq_chip_generic *gc;
+	unsigned long pending;
+	int n, i, irq_base = 0;
+
+	chained_irq_enter(chip, desc);
+
+	for (i = 0; i < nbanks; i++, irq_base += IRQS_PER_BANK) {
+		gc = irq_get_domain_generic_chip(domain, irq_base);
+
+		while ((pending = stm32_exti_pending(gc))) {
+			for_each_set_bit(n, &pending, IRQS_PER_BANK)
+				generic_handle_domain_irq(domain, irq_base + n);
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static int stm32_exti_set_type(struct irq_data *d,
+			       unsigned int type, u32 *rtsr, u32 *ftsr)
+{
+	u32 mask = BIT(d->hwirq % IRQS_PER_BANK);
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		*rtsr |= mask;
+		*ftsr &= ~mask;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		*rtsr &= ~mask;
+		*ftsr |= mask;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		*rtsr |= mask;
+		*ftsr |= mask;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int stm32_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct stm32_exti_chip_data *chip_data = gc->private;
+	const struct stm32_exti_bank *stm32_bank = chip_data->reg_bank;
+	u32 rtsr, ftsr;
+	int err;
+
+	guard(raw_spinlock)(&gc->lock);
+
+	rtsr = irq_reg_readl(gc, stm32_bank->rtsr_ofst);
+	ftsr = irq_reg_readl(gc, stm32_bank->ftsr_ofst);
+
+	err = stm32_exti_set_type(d, type, &rtsr, &ftsr);
+	if (err)
+		return err;
+
+	irq_reg_writel(gc, rtsr, stm32_bank->rtsr_ofst);
+	irq_reg_writel(gc, ftsr, stm32_bank->ftsr_ofst);
+	return 0;
+}
+
+static void stm32_chip_suspend(struct stm32_exti_chip_data *chip_data,
+			       u32 wake_active)
+{
+	const struct stm32_exti_bank *stm32_bank = chip_data->reg_bank;
+	void __iomem *base = chip_data->host_data->base;
+
+	/* save rtsr, ftsr registers */
+	chip_data->rtsr_cache = readl_relaxed(base + stm32_bank->rtsr_ofst);
+	chip_data->ftsr_cache = readl_relaxed(base + stm32_bank->ftsr_ofst);
+
+	writel_relaxed(wake_active, base + stm32_bank->imr_ofst);
+}
+
+static void stm32_chip_resume(struct stm32_exti_chip_data *chip_data,
+			      u32 mask_cache)
+{
+	const struct stm32_exti_bank *stm32_bank = chip_data->reg_bank;
+	void __iomem *base = chip_data->host_data->base;
+
+	/* restore rtsr, ftsr, registers */
+	writel_relaxed(chip_data->rtsr_cache, base + stm32_bank->rtsr_ofst);
+	writel_relaxed(chip_data->ftsr_cache, base + stm32_bank->ftsr_ofst);
+
+	writel_relaxed(mask_cache, base + stm32_bank->imr_ofst);
+}
+
+static void stm32_irq_suspend(struct irq_chip_generic *gc)
+{
+	struct stm32_exti_chip_data *chip_data = gc->private;
+
+	guard(raw_spinlock)(&gc->lock);
+	stm32_chip_suspend(chip_data, gc->wake_active);
+}
+
+static void stm32_irq_resume(struct irq_chip_generic *gc)
+{
+	struct stm32_exti_chip_data *chip_data = gc->private;
+
+	guard(raw_spinlock)(&gc->lock);
+	stm32_chip_resume(chip_data, gc->mask_cache);
+}
+
+static int stm32_exti_alloc(struct irq_domain *d, unsigned int virq,
+			    unsigned int nr_irqs, void *data)
+{
+	struct irq_fwspec *fwspec = data;
+	irq_hw_number_t hwirq;
+
+	hwirq = fwspec->param[0];
+
+	irq_map_generic_chip(d, virq, hwirq);
+
+	return 0;
+}
+
+static void stm32_exti_free(struct irq_domain *d, unsigned int virq,
+			    unsigned int nr_irqs)
+{
+	struct irq_data *data = irq_domain_get_irq_data(d, virq);
+
+	irq_domain_reset_irq_data(data);
+}
+
+static const struct irq_domain_ops irq_exti_domain_ops = {
+	.map	= irq_map_generic_chip,
+	.alloc  = stm32_exti_alloc,
+	.free	= stm32_exti_free,
+	.xlate	= irq_domain_xlate_twocell,
+};
+
+static void stm32_irq_ack(struct irq_data *d)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct stm32_exti_chip_data *chip_data = gc->private;
+	const struct stm32_exti_bank *stm32_bank = chip_data->reg_bank;
+
+	guard(raw_spinlock)(&gc->lock);
+	irq_reg_writel(gc, d->mask, stm32_bank->rpr_ofst);
+}
+
+static struct
+stm32_exti_host_data *stm32_exti_host_init(const struct stm32_exti_drv_data *dd,
+					   struct device_node *node)
+{
+	struct stm32_exti_host_data *host_data;
+
+	host_data = kzalloc(sizeof(*host_data), GFP_KERNEL);
+	if (!host_data)
+		return NULL;
+
+	host_data->drv_data = dd;
+	host_data->chips_data = kcalloc(dd->bank_nr,
+					sizeof(struct stm32_exti_chip_data),
+					GFP_KERNEL);
+	if (!host_data->chips_data)
+		goto free_host_data;
+
+	host_data->base = of_iomap(node, 0);
+	if (!host_data->base) {
+		pr_err("%pOF: Unable to map registers\n", node);
+		goto free_chips_data;
+	}
+
+	return host_data;
+
+free_chips_data:
+	kfree(host_data->chips_data);
+free_host_data:
+	kfree(host_data);
+
+	return NULL;
+}
+
+static struct
+stm32_exti_chip_data *stm32_exti_chip_init(struct stm32_exti_host_data *h_data,
+					   u32 bank_idx,
+					   struct device_node *node)
+{
+	const struct stm32_exti_bank *stm32_bank;
+	struct stm32_exti_chip_data *chip_data;
+	void __iomem *base = h_data->base;
+
+	stm32_bank = h_data->drv_data->exti_banks[bank_idx];
+	chip_data = &h_data->chips_data[bank_idx];
+	chip_data->host_data = h_data;
+	chip_data->reg_bank = stm32_bank;
+
+	/*
+	 * This IP has no reset, so after hot reboot we should
+	 * clear registers to avoid residue
+	 */
+	writel_relaxed(0, base + stm32_bank->imr_ofst);
+	writel_relaxed(0, base + stm32_bank->emr_ofst);
+
+	pr_info("%pOF: bank%d\n", node, bank_idx);
+
+	return chip_data;
+}
+
+static int __init stm32_exti_init(const struct stm32_exti_drv_data *drv_data,
+				  struct device_node *node)
+{
+	struct stm32_exti_host_data *host_data;
+	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
+	int nr_irqs, ret, i;
+	struct irq_chip_generic *gc;
+	struct irq_domain *domain;
+
+	host_data = stm32_exti_host_init(drv_data, node);
+	if (!host_data)
+		return -ENOMEM;
+
+	domain = irq_domain_create_linear(of_fwnode_handle(node), drv_data->bank_nr * IRQS_PER_BANK,
+					  &irq_exti_domain_ops, NULL);
+	if (!domain) {
+		pr_err("%pOFn: Could not register interrupt domain.\n",
+		       node);
+		ret = -ENOMEM;
+		goto out_unmap;
+	}
+
+	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",
+		       node);
+		goto out_free_domain;
+	}
+
+	for (i = 0; i < drv_data->bank_nr; i++) {
+		const struct stm32_exti_bank *stm32_bank;
+		struct stm32_exti_chip_data *chip_data;
+
+		stm32_bank = drv_data->exti_banks[i];
+		chip_data = stm32_exti_chip_init(host_data, i, node);
+
+		gc = irq_get_domain_generic_chip(domain, i * IRQS_PER_BANK);
+
+		gc->reg_base = host_data->base;
+		gc->chip_types->type = IRQ_TYPE_EDGE_BOTH;
+		gc->chip_types->chip.irq_ack = stm32_irq_ack;
+		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 = irq_gc_set_wake;
+		gc->suspend = stm32_irq_suspend;
+		gc->resume = stm32_irq_resume;
+		gc->wake_enabled = IRQ_MSK(IRQS_PER_BANK);
+
+		gc->chip_types->regs.mask = stm32_bank->imr_ofst;
+		gc->private = (void *)chip_data;
+	}
+
+	nr_irqs = of_irq_count(node);
+	for (i = 0; i < nr_irqs; i++) {
+		unsigned int irq = irq_of_parse_and_map(node, i);
+
+		irq_set_handler_data(irq, domain);
+		irq_set_chained_handler(irq, stm32_irq_handler);
+	}
+
+	return 0;
+
+out_free_domain:
+	irq_domain_remove(domain);
+out_unmap:
+	iounmap(host_data->base);
+	kfree(host_data->chips_data);
+	kfree(host_data);
+	return ret;
+}
+
+static int __init stm32f4_exti_of_init(struct device_node *np,
+				       struct device_node *parent)
+{
+	return stm32_exti_init(&stm32f4xx_drv_data, np);
+}
+
+IRQCHIP_DECLARE(stm32f4_exti, "st,stm32-exti", stm32f4_exti_of_init);
+
+static int __init stm32h7_exti_of_init(struct device_node *np,
+				       struct device_node *parent)
+{
+	return stm32_exti_init(&stm32h7xx_drv_data, np);
+}
+
+IRQCHIP_DECLARE(stm32h7_exti, "st,stm32h7-exti", stm32h7_exti_of_init);