[PATCH v2 1/2] gpio: Add support for IDT 79RC3243x GPIO controller

Thomas Bogendoerfer
2021-04-21T16:20:42Z

IDT 79RC3243x SoCs integrated a gpio controller, which handles up
to 32 gpios. All gpios could be used as interrupt source.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
---
Changes in v2:
- made driver buildable as module
- use for_each_set_bit() in irq dispatch handler
- use gpiochip_get_data instead of own container_of helper
- use module_platform_driver() instead of arch_initcall
- don't default y for Mikrotik RB532

drivers/gpio/Kconfig | 12 +++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-idt3243x.c | 198 +++++++++++++++++++++++++++++++++++
3 files changed, 211 insertions(+)
create mode 100644 drivers/gpio/gpio-idt3243x.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e3607ec4c2e8..2948eb4ab8a5 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -770,6 +770,18 @@ config GPIO_MSC313
Say Y here to support the main GPIO block on MStar/SigmaStar
ARMv7 based SoCs.

+config GPIO_IDT3243X
+ tristate "IDT 79RC3243X GPIO support"
+ depends on MIKROTIK_RB532 || COMPILE_TEST
+ select GPIO_GENERIC
+ select GPIOLIB_IRQCHIP
+ help
+ Select this option to enable GPIO driver for
+ IDT 79RC3243X SoC devices.
+
+ To compile this driver as a module, choose M here: the module will
+ be called gpio-idt3243x.
+
endmenu

menu "Port-mapped I/O GPIO drivers"
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index c58a90a3c3b1..75dd9c5665c5 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -67,6 +67,7 @@ obj-$(CONFIG_GPIO_HISI) += gpio-hisi.o
obj-$(CONFIG_GPIO_HLWD) += gpio-hlwd.o
obj-$(CONFIG_HTC_EGPIO) += gpio-htc-egpio.o
obj-$(CONFIG_GPIO_ICH) += gpio-ich.o
+obj-$(CONFIG_GPIO_IDT3243X) += gpio-idt3243x.o
obj-$(CONFIG_GPIO_IOP) += gpio-iop.o
obj-$(CONFIG_GPIO_IT87) += gpio-it87.o
obj-$(CONFIG_GPIO_IXP4XX) += gpio-ixp4xx.o
diff --git a/drivers/gpio/gpio-idt3243x.c b/drivers/gpio/gpio-idt3243x.c
new file mode 100644
index 000000000000..50e132cb3d47
--- /dev/null
+++ b/drivers/gpio/gpio-idt3243x.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for IDT/Renesas 79RC3243x Interrupt Controller.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.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 IDT_PIC_IRQ_PEND 0x00
+#define IDT_PIC_IRQ_MASK 0x08
+
+#define IDT_GPIO_DIR 0x04
+#define IDT_GPIO_DATA 0x08
+#define IDT_GPIO_ILEVEL 0x0C
+#define IDT_GPIO_ISTAT 0x10
+
+struct idt_gpio_ctrl {
+ struct gpio_chip gc;
+ void __iomem *pic;
+ void __iomem *gpio;
+ u32 mask_cache;
+};
+
+static void idt_gpio_dispatch(struct irq_desc *desc)
+{
+ struct gpio_chip *gc = irq_desc_get_handler_data(desc);
+ struct idt_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+ struct irq_chip *host_chip = irq_desc_get_chip(desc);
+ unsigned int bit, virq;
+ unsigned long pending;
+
+ chained_irq_enter(host_chip, desc);
+
+ pending = readl(ctrl->pic + IDT_PIC_IRQ_PEND);
+ pending &= ~ctrl->mask_cache;
+ for_each_set_bit(bit, &pending, gc->ngpio) {
+ virq = irq_linear_revmap(gc->irq.domain, bit);
+ if (virq)
+ generic_handle_irq(virq);
+ }
+
+ chained_irq_exit(host_chip, desc);
+}
+
+static int idt_gpio_irq_set_type(struct irq_data *d, unsigned int flow_type)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct idt_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+ unsigned int sense = flow_type & IRQ_TYPE_SENSE_MASK;
+ u32 ilevel;
+
+ if (sense & ~(IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
+ return -EINVAL;
+
+ ilevel = readl(ctrl->gpio + IDT_GPIO_ILEVEL);
+ if (sense & IRQ_TYPE_LEVEL_HIGH)
+ ilevel |= BIT(d->hwirq);
+ else if (sense & IRQ_TYPE_LEVEL_LOW)
+ ilevel &= ~BIT(d->hwirq);
+ else
+ return -EINVAL;
+
+ writel(ilevel, ctrl->gpio + IDT_GPIO_ILEVEL);
+ return 0;
+}
+
+static void idt_gpio_ack(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct idt_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+
+ writel(~BIT(d->hwirq), ctrl->gpio + IDT_GPIO_ISTAT);
+}
+
+static void idt_gpio_mask(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct idt_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+
+ ctrl->mask_cache |= BIT(d->hwirq);
+ writel(ctrl->mask_cache, ctrl->pic + IDT_PIC_IRQ_MASK);
+}
+
+static void idt_gpio_unmask(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct idt_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+
+ ctrl->mask_cache &= ~BIT(d->hwirq);
+ writel(ctrl->mask_cache, ctrl->pic + IDT_PIC_IRQ_MASK);
+}
+
+static struct irq_chip idt_gpio_irqchip = {
+ .name = "IDTGPIO",
+ .irq_mask = idt_gpio_mask,
+ .irq_ack = idt_gpio_ack,
+ .irq_unmask = idt_gpio_unmask,
+ .irq_set_type = idt_gpio_irq_set_type
+};
+
+static int idt_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct gpio_irq_chip *girq;
+ struct idt_gpio_ctrl *ctrl;
+ unsigned int parent_irq;
+ int ngpios;
+ int ret;
+
+ ret = device_property_read_u32(dev, "ngpios", &ngpios);
+ if (ret) {
+ dev_err(dev, "ngpios property is not valid\n");
+ return ret;
+ }
+
+ ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
+ if (!ctrl)
+ return -ENOMEM;
+
+ ctrl->gpio = devm_platform_ioremap_resource_byname(pdev, "gpio");
+ if (!ctrl->gpio)
+ return -ENOMEM;
+
+ ctrl->gc.parent = dev;
+
+ ret = bgpio_init(&ctrl->gc, &pdev->dev, 4, ctrl->gpio + IDT_GPIO_DATA,
+ NULL, NULL, ctrl->gpio + IDT_GPIO_DIR, NULL, 0);
+ if (ret) {
+ dev_err(dev, "bgpio_init failed\n");
+ return ret;
+ }
+ ctrl->gc.ngpio = ngpios;
+
+ ctrl->pic = devm_platform_ioremap_resource_byname(pdev, "pic");
+ if (!ctrl->pic)
+ return -ENOMEM;
+
+ parent_irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
+ if (!parent_irq) {
+ dev_err(&pdev->dev, "Failed to map parent IRQ!\n");
+ return -EINVAL;
+ }
+
+ /* Mask interrupts. */
+ ctrl->mask_cache = 0xffffffff;
+ writel(ctrl->mask_cache, ctrl->pic + IDT_PIC_IRQ_MASK);
+
+ girq = &ctrl->gc.irq;
+ girq->chip = &idt_gpio_irqchip;
+ girq->parent_handler = idt_gpio_dispatch;
+ girq->num_parents = 1;
+ girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
+ GFP_KERNEL);
+ if (!girq->parents) {
+ ret = -ENOMEM;
+ goto out_unmap_irq;
+ }
+ girq->parents[0] = parent_irq;
+ girq->default_type = IRQ_TYPE_NONE;
+ girq->handler = handle_level_irq;
+
+ ret = devm_gpiochip_add_data(&pdev->dev, &ctrl->gc, ctrl);
+ if (ret)
+ goto out_unmap_irq;
+
+ return 0;
+
+out_unmap_irq:
+ irq_dispose_mapping(parent_irq);
+ return ret;
+}
+
+static const struct of_device_id idt_gpio_of_match[] = {
+ { .compatible = "idt,3243x-gpio" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, idt_gpio_of_match);
+
+static struct platform_driver idt_gpio_driver = {
+ .probe = idt_gpio_probe,
+ .driver = {
+ .name = "idt3243x-gpio",
+ .of_match_table = idt_gpio_of_match,
+ },
+};
+module_platform_driver(idt_gpio_driver);
+
+MODULE_DESCRIPTION("IDT 79RC3243x GPIO/PIC Driver");
+MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
+MODULE_LICENSE("GPL");
--
2.29.2