Add a driver supporting the GPIO interrupt controller on certain
Amlogic meson SoC's.
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
---
v5:
- changed Kconfig entry based on Neil's suggestion
- added authors
- extended explanation why 2 * n hwirqs are used
v6:
- change DT property parent-interrupts to interrupts
---
drivers/irqchip/Kconfig | 5 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-meson-gpio.c | 295 +++++++++++++++++++++++++++++++++++++++
3 files changed, 302 insertions(+)
create mode 100644 drivers/irqchip/irq-meson-gpio.c
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 478f8ace..bdc86e14 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -301,3 +301,8 @@ config QCOM_IRQ_COMBINER
help
Say yes here to add support for the IRQ combiner devices embedded
in Qualcomm Technologies chips.
+
+config MESON_GPIO_INTC
+ bool
+ depends on ARCH_MESON
+ default y
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index b64c59b8..1be482bd 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -76,3 +76,4 @@ obj-$(CONFIG_EZNPS_GIC) += irq-eznps.o
obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o
obj-$(CONFIG_STM32_EXTI) += irq-stm32-exti.o
obj-$(CONFIG_QCOM_IRQ_COMBINER) += qcom-irq-combiner.o
+obj-$(CONFIG_MESON_GPIO_INTC) += irq-meson-gpio.o
diff --git a/drivers/irqchip/irq-meson-gpio.c b/drivers/irqchip/irq-meson-gpio.c
new file mode 100644
index 00000000..b09228ea
--- /dev/null
+++ b/drivers/irqchip/irq-meson-gpio.c
@@ -0,0 +1,295 @@
+/*
+ * Amlogic Meson GPIO IRQ chip driver
+ *
+ * Copyright (c) 2015 Endless Mobile, Inc.
+ * Author: Carlo Caione <carlo@xxxxxxxxxxxx>
+ * Copyright (c) 2016 BayLibre, SAS.
+ * Author: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
+ * Copyright (c) 2017 Heiner Kallweit <hkallweit1@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2.
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+
+#define REG_EDGE_POL 0x00
+#define REG_PIN_03_SEL 0x04
+#define REG_PIN_47_SEL 0x08
+#define REG_FILTER_SEL 0x0c
+
+#define REG_EDGE_POL_MASK(x) (BIT(x) | BIT(16 + (x)))
+#define REG_EDGE_POL_EDGE(x) BIT(x)
+#define REG_EDGE_POL_LOW(x) BIT(16 + (x))
+
+#define MAX_PARENT_IRQ_NUM 8
+
+/* maximum number of GPIO IRQs on supported platforms */
+#define MAX_NUM_GPIO_IRQ 133
+
+/*
+ * In case of IRQ_TYPE_EDGE_BOTH we need two parent interrupts, one for each
+ * edge. That's due to HW constraints.
+ * We use format 2 * GPIO_HWIRQ +(0|1) for the hwirq, so we can have one
+ * GPIO_HWIRQ twice and derive the GPIO_HWIRQ from hwirq by shifting hwirq
+ * one bit to the right.
+ */
+#define NUM_GPIO_HWIRQ (2 * MAX_NUM_GPIO_IRQ)
+
+struct meson_irq_slot {
+ unsigned int irq;
+ unsigned int owner;
+};
+
+struct meson_data {
+ struct regmap *regmap;
+ struct meson_irq_slot slots[MAX_PARENT_IRQ_NUM];
+ unsigned int num_slots;
+ struct mutex lock;
+};
+
+static int meson_alloc_irq_slot(struct meson_data *md, unsigned int virq)
+{
+ int i, slot = -ENOSPC;
+
+ mutex_lock(&md->lock);
+
+ for (i = 0; i < md->num_slots && slot < 0; i++)
+ if (!md->slots[i].owner) {
+ md->slots[i].owner = virq;
+ slot = i;
+ }
+
+ mutex_unlock(&md->lock);
+
+ return slot;
+}
+
+static void meson_free_irq_slot(struct meson_data *md, unsigned int virq)
+{
+ int i;
+
+ mutex_lock(&md->lock);
+
+ for (i = 0; i < md->num_slots; i++)
+ if (md->slots[i].owner == virq) {
+ md->slots[i].owner = 0;
+ break;
+ }
+
+ mutex_unlock(&md->lock);
+}
+
+static int meson_find_irq_slot(struct meson_data *md, unsigned int virq)
+{
+ int i, slot = -EINVAL;
+
+ mutex_lock(&md->lock);
+
+ for (i = 0; i < md->num_slots && slot < 0; i++)
+ if (md->slots[i].owner == virq)
+ slot = i;
+
+ mutex_unlock(&md->lock);
+
+ return slot;
+}
+
+static void meson_set_hwirq(struct meson_data *md, int idx, unsigned int hwirq)
+{
+ int reg = idx > 3 ? REG_PIN_47_SEL : REG_PIN_03_SEL;
+ int shift = 8 * (idx % 4);
+
+ regmap_update_bits(md->regmap, reg, 0xff << shift,
+ hwirq << shift);
+}
+
+static void meson_irq_set_hwirq(struct irq_data *data, unsigned int hwirq)
+{
+ struct meson_data *md = data->domain->host_data;
+ int slot = meson_find_irq_slot(md, data->irq);
+
+ if (slot >= 0)
+ meson_set_hwirq(md, slot, hwirq);
+}
+
+static int meson_irq_set_type(struct irq_data *data, unsigned int type)
+{
+ struct meson_data *md = data->domain->host_data;
+ int slot;
+ unsigned int val = 0;
+
+ if (type == IRQ_TYPE_EDGE_BOTH)
+ return -EINVAL;
+
+ slot = meson_find_irq_slot(md, data->irq);
+ if (slot < 0)
+ return slot;
+
+ if (type & IRQ_TYPE_EDGE_BOTH)
+ val |= REG_EDGE_POL_EDGE(slot);
+
+ if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_EDGE_FALLING))
+ val |= REG_EDGE_POL_LOW(slot);
+
+ regmap_update_bits(md->regmap, REG_EDGE_POL,
+ REG_EDGE_POL_MASK(slot), val);
+
+ if (type & IRQ_TYPE_EDGE_BOTH)
+ val = IRQ_TYPE_EDGE_RISING;
+ else
+ val = IRQ_TYPE_LEVEL_HIGH;
+
+ return irq_chip_set_type_parent(data, val);
+}
+
+static unsigned int meson_irq_startup(struct irq_data *data)
+{
+ irq_chip_unmask_parent(data);
+ /*
+ * An extra bit was added to allow having the same gpio hwirq twice
+ * for handling IRQ_TYPE_EDGE_BOTH. Remove this bit to get the
+ * gpio hwirq.
+ */
+ meson_irq_set_hwirq(data, data->hwirq >> 1);
+
+ return 0;
+}
+
+static void meson_irq_shutdown(struct irq_data *data)
+{
+ meson_irq_set_hwirq(data, 0xff);
+ irq_chip_mask_parent(data);
+}
+
+static struct irq_chip meson_irq_chip = {
+ .name = "meson_gpio_intc",
+ .irq_set_type = meson_irq_set_type,
+ .irq_eoi = irq_chip_eoi_parent,
+ .irq_mask = irq_chip_mask_parent,
+ .irq_unmask = irq_chip_unmask_parent,
+ .irq_startup = meson_irq_startup,
+ .irq_shutdown = meson_irq_shutdown,
+ .irq_set_affinity = irq_chip_set_affinity_parent,
+};
+
+static int meson_irq_alloc(struct irq_domain *d, unsigned int virq,
+ unsigned int nr_irqs, void *data)
+{
+ struct irq_fwspec parent_fwspec, *fwspec = data;
+ struct meson_data *md = d->host_data;
+ irq_hw_number_t hwirq;
+ int ret, slot;
+
+ slot = meson_alloc_irq_slot(md, virq);
+ if (slot < 0)
+ return slot;
+
+ hwirq = fwspec->param[0];
+ irq_domain_set_hwirq_and_chip(d, virq, hwirq, &meson_irq_chip, NULL);
+
+ parent_fwspec.fwnode = d->parent->fwnode;
+ parent_fwspec.param_count = 3;
+ parent_fwspec.param[0] = 0; /* SPI */
+ parent_fwspec.param[1] = md->slots[slot].irq;
+ parent_fwspec.param[2] = IRQ_TYPE_NONE;
+
+ ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, &parent_fwspec);
+ if (ret)
+ meson_free_irq_slot(md, virq);
+
+ return ret;
+}
+
+static void meson_irq_free(struct irq_domain *d, unsigned int virq,
+ unsigned int nr_irqs)
+{
+ struct meson_data *md = d->host_data;
+
+ irq_domain_free_irqs_common(d, virq, nr_irqs);
+ meson_free_irq_slot(md, virq);
+}
+
+static const struct irq_domain_ops meson_irq_ops = {
+ .alloc = meson_irq_alloc,
+ .free = meson_irq_free,
+ .xlate = irq_domain_xlate_twocell,
+};
+
+static int meson_get_irqs(struct meson_data *md, struct device_node *node)
+{
+ int ret, i;
+ u32 irq;
+
+ for (i = 0; i < MAX_PARENT_IRQ_NUM; i++) {
+ ret = of_property_read_u32_index(node, "interrupts", i, &irq);
+ if (ret)
+ break;
+ md->slots[i].irq = irq;
+ }
+
+ md->num_slots = i;
+
+ return i ? 0 : -EINVAL;
+}
+
+static const struct regmap_config meson_regmap_config = {
+ .reg_bits = 32,
+ .reg_stride = 4,
+ .val_bits = 32,
+ .max_register = REG_FILTER_SEL,
+};
+
+static int __init meson_gpio_irq_init(struct device_node *node,
+ struct device_node *parent)
+{
+ struct irq_domain *meson_irq_domain, *parent_domain;
+ struct meson_data *md;
+ void __iomem *io_base;
+ int ret;
+
+ md = kzalloc(sizeof(*md), GFP_KERNEL);
+ if (!md)
+ return -ENOMEM;
+
+ mutex_init(&md->lock);
+
+ io_base = of_iomap(node, 0);
+ if (!io_base)
+ return -EINVAL;
+
+ md->regmap = regmap_init_mmio(NULL, io_base, &meson_regmap_config);
+ if (IS_ERR(md->regmap))
+ return PTR_ERR(md->regmap);
+
+ /* initialize to IRQ_TYPE_LEVEL_HIGH */
+ regmap_write(md->regmap, REG_EDGE_POL, 0);
+ /* disable all GPIO interrupt sources */
+ regmap_write(md->regmap, REG_PIN_03_SEL, 0xffffffff);
+ regmap_write(md->regmap, REG_PIN_47_SEL, 0xffffffff);
+ /* disable filtering */
+ regmap_write(md->regmap, REG_FILTER_SEL, 0);
+
+ ret = meson_get_irqs(md, node);
+ if (ret)
+ return ret;
+
+ parent_domain = irq_find_host(parent);
+ if (!parent_domain)
+ return -ENXIO;
+
+ meson_irq_domain = irq_domain_add_hierarchy(parent_domain, 0,
+ NUM_GPIO_HWIRQ, node,
+ &meson_irq_ops, md);
+ return meson_irq_domain ? 0 : -EINVAL;
+}
+
+IRQCHIP_DECLARE(meson_gpio_irq, "amlogic,meson-gpio-intc", meson_gpio_irq_init);
--
2.13.0
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