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Subject[PATCH v12] gpio: add a driver for the Synopsys DesignWare APB GPIO block
Date
From: Jamie Iles <jamie@jamieiles.com>

The Synopsys DesignWare block is used in some ARM devices (picoxcell)
and can be configured to provide multiple banks of GPIO pins.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Alan Tull <atull@altera.com>
Reviewed-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>

v12: - Add irq_startup/shutdown
- do irq_create_mapping() in probe, irq_find_mapping() in to_irq()
- Adjust mappings to show support for 1 gpio per port.
- gpio-cells = <1>
v11: - Use NULL when checking existence of 'interrupts' property
- Bindings descriptions cleanup
v10: - in documentation nr-gpio -> nr-gpios
v9: - cleanup in dt bindings doc
- use of_get_child_count()
v8: - remove socfpga.dtsi changes
- minor cleanup in devicetree documentation
v7: - use irq_generic_chip
- support one irq per gpio line or one irq for many
- s/bank/port/ and other cleanup
v6: - (atull) squash the set of patches
- use linear irq domain
- build fixes. Original driver was reviewed on v3.2.
- Fix setting irq edge type for 'rising' and 'both'.
- Support as a loadable module.
- Use bgpio_chip's spinlock during register access.
- Clean up register names to match spec
- s/bank/port/ because register names use the word 'port'
- s/nr-gpio/nr-gpios/
- don't get/put the of_node
- remove signoffs/acked-by's because of changes
- other cleanup
v5: - handle sparse bank population correctly
v3: - depend on rather than select IRQ_DOMAIN
- split IRQ support into a separate patch
v2: - use Rob Herring's irqdomain in generic irq chip patches
- use reg property to indicate bank index
- support irqs on both edges based on LinusW's u300 driver
---
.../devicetree/bindings/gpio/snps-dwapb-gpio.txt | 57 +++
drivers/gpio/Kconfig | 9 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-dwapb.c | 438 ++++++++++++++++++++
4 files changed, 505 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt
create mode 100644 drivers/gpio/gpio-dwapb.c

diff --git a/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt b/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt
new file mode 100644
index 0000000..0934950
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/snps-dwapb-gpio.txt
@@ -0,0 +1,57 @@
+* Synopsys DesignWare APB GPIO controller
+
+Required properties:
+- compatible : Should contain "snps,dw-apb-gpio"
+- reg : Address and length of the register set for the device.
+- #address-cells : should be 1 (for addressing port subnodes).
+- #size-cells : should be 0 (port subnodes).
+
+The GPIO controller has a configurable number of ports, each of which are
+represented as child nodes with the following properties:
+
+Required properties:
+- compatible : "snps,dw-apb-gpio-port"
+- gpio-controller : Marks the device node as a gpio controller.
+- #gpio-cells : Should be 1. It is the pin number.
+- reg : The integer port index of the port, a single cell.
+
+Optional properties:
+- interrupt-controller : The first port may be configured to be an interrupt
+controller.
+- #interrupt-cells : Specifies the number of cells needed to encode an
+ interrupt. Shall be set to 2. The first cell defines the interrupt number,
+ the second encodes the triger flags encoded as described in
+ Documentation/devicetree/bindings/interrupts.txt
+- interrupt-parent : The parent interrupt controller.
+- interrupts : The interrupt to the parent controller raised when GPIOs
+ generate the interrupts.
+- snps,nr-gpios : The number of pins in the port, a single cell.
+
+Example:
+
+gpio: gpio@20000 {
+ compatible = "snps,dw-apb-gpio";
+ reg = <0x20000 0x1000>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ porta: gpio-controller@0 {
+ compatible = "snps,dw-apb-gpio-port";
+ gpio-controller;
+ #gpio-cells = <1>;
+ snps,nr-gpios = <8>;
+ reg = <0>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ interrupt-parent = <&vic1>;
+ interrupts = <0>;
+ };
+
+ portb: gpio-controller@1 {
+ compatible = "snps,dw-apb-gpio-port";
+ gpio-controller;
+ #gpio-cells = <1>;
+ snps,nr-gpios = <8>;
+ reg = <1>;
+ };
+};
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 903f24d..9979017 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -128,6 +128,15 @@ config GPIO_GENERIC_PLATFORM
help
Say yes here to support basic platform_device memory-mapped GPIO controllers.

+config GPIO_DWAPB
+ tristate "Synopsys DesignWare APB GPIO driver"
+ select GPIO_GENERIC
+ select GENERIC_IRQ_CHIP
+ depends on OF_GPIO && IRQ_DOMAIN
+ help
+ Say Y or M here to build support for the Synopsys DesignWare APB
+ GPIO block.
+
config GPIO_IT8761E
tristate "IT8761E GPIO support"
depends on X86 # unconditional access to IO space.
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 5d50179..2d09f04 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_GPIO_CS5535) += gpio-cs5535.o
obj-$(CONFIG_GPIO_DA9052) += gpio-da9052.o
obj-$(CONFIG_GPIO_DA9055) += gpio-da9055.o
obj-$(CONFIG_GPIO_DAVINCI) += gpio-davinci.o
+obj-$(CONFIG_GPIO_DWAPB) += gpio-dwapb.o
obj-$(CONFIG_GPIO_EM) += gpio-em.o
obj-$(CONFIG_GPIO_EP93XX) += gpio-ep93xx.o
obj-$(CONFIG_GPIO_F7188X) += gpio-f7188x.o
diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
new file mode 100644
index 0000000..2797fbb
--- /dev/null
+++ b/drivers/gpio/gpio-dwapb.c
@@ -0,0 +1,438 @@
+/*
+ * Copyright (c) 2011 Jamie Iles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * All enquiries to support@picochip.com
+ */
+#include <linux/basic_mmio_gpio.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+#define GPIO_SWPORTA_DR 0x00
+#define GPIO_SWPORTA_DDR 0x04
+#define GPIO_SWPORTB_DR 0x0c
+#define GPIO_SWPORTB_DDR 0x10
+#define GPIO_SWPORTC_DR 0x18
+#define GPIO_SWPORTC_DDR 0x1c
+#define GPIO_SWPORTD_DR 0x24
+#define GPIO_SWPORTD_DDR 0x28
+#define GPIO_INTEN 0x30
+#define GPIO_INTMASK 0x34
+#define GPIO_INTTYPE_LEVEL 0x38
+#define GPIO_INT_POLARITY 0x3c
+#define GPIO_INTSTATUS 0x40
+#define GPIO_PORTA_EOI 0x4c
+#define GPIO_EXT_PORTA 0x50
+#define GPIO_EXT_PORTB 0x54
+#define GPIO_EXT_PORTC 0x58
+#define GPIO_EXT_PORTD 0x5c
+
+#define DWAPB_MAX_PORTS 4
+#define GPIO_EXT_PORT_SIZE (GPIO_EXT_PORTB - GPIO_EXT_PORTA)
+#define GPIO_SWPORT_DR_SIZE (GPIO_SWPORTB_DR - GPIO_SWPORTA_DR)
+#define GPIO_SWPORT_DDR_SIZE (GPIO_SWPORTB_DDR - GPIO_SWPORTA_DDR)
+
+struct dwapb_gpio;
+
+struct dwapb_gpio_port {
+ struct bgpio_chip bgc;
+ bool is_registered;
+ struct dwapb_gpio *gpio;
+};
+
+struct dwapb_gpio {
+ struct device *dev;
+ void __iomem *regs;
+ struct dwapb_gpio_port *ports;
+ unsigned int nr_ports;
+ struct irq_domain *domain;
+};
+
+static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
+{
+ struct bgpio_chip *bgc = to_bgpio_chip(gc);
+ struct dwapb_gpio_port *port = container_of(bgc, struct
+ dwapb_gpio_port, bgc);
+ struct dwapb_gpio *gpio = port->gpio;
+
+ return irq_find_mapping(gpio->domain, offset);
+}
+
+static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs)
+{
+ u32 v = readl(gpio->regs + GPIO_INT_POLARITY);
+
+ if (gpio_get_value(gpio->ports[0].bgc.gc.base + offs))
+ v &= ~BIT(offs);
+ else
+ v |= BIT(offs);
+
+ writel(v, gpio->regs + GPIO_INT_POLARITY);
+}
+
+static void dwapb_irq_handler(u32 irq, struct irq_desc *desc)
+{
+ struct dwapb_gpio *gpio = irq_get_handler_data(irq);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ u32 irq_status = readl_relaxed(gpio->regs + GPIO_INTSTATUS);
+
+ while (irq_status) {
+ int hwirq = fls(irq_status) - 1;
+ int gpio_irq = irq_find_mapping(gpio->domain, hwirq);
+
+ generic_handle_irq(gpio_irq);
+ irq_status &= ~BIT(hwirq);
+
+ if ((irq_get_trigger_type(gpio_irq) & IRQ_TYPE_SENSE_MASK)
+ == IRQ_TYPE_EDGE_BOTH)
+ dwapb_toggle_trigger(gpio, hwirq);
+ }
+
+ if (chip->irq_eoi)
+ chip->irq_eoi(irq_desc_get_irq_data(desc));
+}
+
+static void dwapb_irq_enable(struct irq_data *d)
+{
+ struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
+ struct dwapb_gpio *gpio = igc->private;
+ struct bgpio_chip *bgc = &gpio->ports[0].bgc;
+ unsigned long flags;
+ u32 val;
+
+ spin_lock_irqsave(&bgc->lock, flags);
+ val = readl(gpio->regs + GPIO_INTEN);
+ val |= BIT(d->hwirq);
+ writel(val, gpio->regs + GPIO_INTEN);
+ spin_unlock_irqrestore(&bgc->lock, flags);
+}
+
+static void dwapb_irq_disable(struct irq_data *d)
+{
+ struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
+ struct dwapb_gpio *gpio = igc->private;
+ struct bgpio_chip *bgc = &gpio->ports[0].bgc;
+ unsigned long flags;
+ u32 val;
+
+ spin_lock_irqsave(&bgc->lock, flags);
+ val = readl(gpio->regs + GPIO_INTEN);
+ val &= ~BIT(d->hwirq);
+ writel(val, gpio->regs + GPIO_INTEN);
+ spin_unlock_irqrestore(&bgc->lock, flags);
+}
+
+static unsigned int dwapb_irq_startup(struct irq_data *d)
+{
+ struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
+ struct dwapb_gpio *gpio = igc->private;
+ struct bgpio_chip *bgc = &gpio->ports[0].bgc;
+
+ if (gpio_lock_as_irq(&bgc->gc, irqd_to_hwirq(d)))
+ dev_err(gpio->dev, "unable to lock HW IRQ %lu for IRQ\n",
+ irqd_to_hwirq(d));
+ dwapb_irq_enable(d);
+ return 0;
+}
+
+static void dwapb_irq_shutdown(struct irq_data *d)
+{
+ struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
+ struct dwapb_gpio *gpio = igc->private;
+ struct bgpio_chip *bgc = &gpio->ports[0].bgc;
+
+ dwapb_irq_disable(d);
+ gpio_unlock_as_irq(&bgc->gc, irqd_to_hwirq(d));
+}
+
+static int dwapb_irq_set_type(struct irq_data *d, u32 type)
+{
+ struct irq_chip_generic *igc = irq_data_get_irq_chip_data(d);
+ struct dwapb_gpio *gpio = igc->private;
+ struct bgpio_chip *bgc = &gpio->ports[0].bgc;
+ int bit = d->hwirq;
+ unsigned long level, polarity, flags;
+
+ if (type & ~(IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING |
+ IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
+ return -EINVAL;
+
+ spin_lock_irqsave(&bgc->lock, flags);
+ level = readl(gpio->regs + GPIO_INTTYPE_LEVEL);
+ polarity = readl(gpio->regs + GPIO_INT_POLARITY);
+
+ switch (type) {
+ case IRQ_TYPE_EDGE_BOTH:
+ level |= BIT(bit);
+ dwapb_toggle_trigger(gpio, bit);
+ break;
+ case IRQ_TYPE_EDGE_RISING:
+ level |= BIT(bit);
+ polarity |= BIT(bit);
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ level |= BIT(bit);
+ polarity &= ~BIT(bit);
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ level &= ~BIT(bit);
+ polarity |= BIT(bit);
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ level &= ~BIT(bit);
+ polarity &= ~BIT(bit);
+ break;
+ }
+
+ writel(level, gpio->regs + GPIO_INTTYPE_LEVEL);
+ writel(polarity, gpio->regs + GPIO_INT_POLARITY);
+ spin_unlock_irqrestore(&bgc->lock, flags);
+
+ return 0;
+}
+
+static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
+ struct dwapb_gpio_port *port)
+{
+ struct gpio_chip *gc = &port->bgc.gc;
+ struct device_node *node = gc->of_node;
+ struct irq_chip_generic *irq_gc;
+ unsigned int hwirq, ngpio = gc->ngpio;
+ struct irq_chip_type *ct;
+ int err, irq;
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (!irq) {
+ dev_warn(gpio->dev, "no irq for bank %s\n",
+ port->bgc.gc.of_node->full_name);
+ return;
+ }
+
+ gpio->domain = irq_domain_add_linear(node, ngpio,
+ &irq_generic_chip_ops, gpio);
+ if (!gpio->domain)
+ return;
+
+ err = irq_alloc_domain_generic_chips(gpio->domain, ngpio, 1,
+ "gpio-dwapb", handle_level_irq,
+ IRQ_NOREQUEST, 0,
+ IRQ_GC_INIT_NESTED_LOCK);
+ if (err) {
+ dev_info(gpio->dev, "irq_alloc_domain_generic_chips failed\n");
+ irq_domain_remove(gpio->domain);
+ gpio->domain = NULL;
+ return;
+ }
+
+ irq_gc = irq_get_domain_generic_chip(gpio->domain, 0);
+ if (!irq_gc) {
+ irq_domain_remove(gpio->domain);
+ gpio->domain = NULL;
+ return;
+ }
+
+ irq_gc->reg_base = gpio->regs;
+ irq_gc->private = gpio;
+
+ ct = irq_gc->chip_types;
+ ct->chip.irq_ack = irq_gc_ack_set_bit;
+ ct->chip.irq_mask = irq_gc_mask_set_bit;
+ ct->chip.irq_unmask = irq_gc_mask_clr_bit;
+ ct->chip.irq_set_type = dwapb_irq_set_type;
+ ct->chip.irq_enable = dwapb_irq_enable;
+ ct->chip.irq_disable = dwapb_irq_disable;
+ ct->chip.irq_startup = dwapb_irq_startup;
+ ct->chip.irq_shutdown = dwapb_irq_shutdown;
+ ct->regs.ack = GPIO_PORTA_EOI;
+ ct->regs.mask = GPIO_INTMASK;
+
+ irq_setup_generic_chip(irq_gc, IRQ_MSK(port->bgc.gc.ngpio),
+ IRQ_GC_INIT_NESTED_LOCK, IRQ_NOREQUEST, 0);
+
+ irq_set_chained_handler(irq, dwapb_irq_handler);
+ irq_set_handler_data(irq, gpio);
+
+ for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
+ irq_create_mapping(gpio->domain, hwirq);
+
+ port->bgc.gc.to_irq = dwapb_gpio_to_irq;
+}
+
+static void dwapb_irq_teardown(struct dwapb_gpio *gpio)
+{
+ struct dwapb_gpio_port *port = &gpio->ports[0];
+ struct gpio_chip *gc = &port->bgc.gc;
+ unsigned int ngpio = gc->ngpio;
+ irq_hw_number_t hwirq;
+
+ if (!gpio->domain)
+ return;
+
+ for (hwirq = 0 ; hwirq < ngpio ; hwirq++)
+ irq_dispose_mapping(irq_find_mapping(gpio->domain, hwirq));
+
+ irq_domain_remove(gpio->domain);
+ gpio->domain = NULL;
+}
+
+static int dwapb_gpio_add_port(struct dwapb_gpio *gpio,
+ struct device_node *port_np,
+ unsigned int offs)
+{
+ struct dwapb_gpio_port *port;
+ u32 port_idx, ngpio;
+ void __iomem *dat, *set, *dirout;
+ int err;
+
+ if (of_property_read_u32(port_np, "reg", &port_idx) ||
+ port_idx >= DWAPB_MAX_PORTS) {
+ dev_err(gpio->dev, "missing/invalid port index for %s\n",
+ port_np->full_name);
+ return -EINVAL;
+ }
+
+ port = &gpio->ports[offs];
+ port->gpio = gpio;
+
+ if (of_property_read_u32(port_np, "snps,nr-gpios", &ngpio)) {
+ dev_info(gpio->dev, "failed to get number of gpios for %s\n",
+ port_np->full_name);
+ ngpio = 32;
+ }
+
+ dat = gpio->regs + GPIO_EXT_PORTA + (port_idx * GPIO_EXT_PORT_SIZE);
+ set = gpio->regs + GPIO_SWPORTA_DR + (port_idx * GPIO_SWPORT_DR_SIZE);
+ dirout = gpio->regs + GPIO_SWPORTA_DDR +
+ (port_idx * GPIO_SWPORT_DDR_SIZE);
+
+ err = bgpio_init(&port->bgc, gpio->dev, 4, dat, set, NULL, dirout,
+ NULL, false);
+ if (err) {
+ dev_err(gpio->dev, "failed to init gpio chip for %s\n",
+ port_np->full_name);
+ return err;
+ }
+
+ port->bgc.gc.ngpio = ngpio;
+ port->bgc.gc.of_node = port_np;
+
+ /*
+ * Only port A can provide interrupts in all configurations of the IP.
+ */
+ if (port_idx == 0 &&
+ of_property_read_bool(port_np, "interrupt-controller"))
+ dwapb_configure_irqs(gpio, port);
+
+ err = gpiochip_add(&port->bgc.gc);
+ if (err)
+ dev_err(gpio->dev, "failed to register gpiochip for %s\n",
+ port_np->full_name);
+ else
+ port->is_registered = true;
+
+ return err;
+}
+
+static void dwapb_gpio_unregister(struct dwapb_gpio *gpio)
+{
+ unsigned int m;
+
+ for (m = 0; m < gpio->nr_ports; ++m)
+ if (gpio->ports[m].is_registered)
+ WARN_ON(gpiochip_remove(&gpio->ports[m].bgc.gc));
+}
+
+static int dwapb_gpio_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct dwapb_gpio *gpio;
+ struct device_node *np;
+ int err;
+ unsigned int offs = 0;
+
+ gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
+ if (!gpio)
+ return -ENOMEM;
+ gpio->dev = &pdev->dev;
+
+ gpio->nr_ports = of_get_child_count(pdev->dev.of_node);
+ if (!gpio->nr_ports) {
+ err = -EINVAL;
+ goto out_err;
+ }
+ gpio->ports = devm_kzalloc(&pdev->dev, gpio->nr_ports *
+ sizeof(*gpio->ports), GFP_KERNEL);
+ if (!gpio->ports) {
+ err = -ENOMEM;
+ goto out_err;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ gpio->regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(gpio->regs)) {
+ err = PTR_ERR(gpio->regs);
+ goto out_err;
+ }
+
+ for_each_child_of_node(pdev->dev.of_node, np) {
+ err = dwapb_gpio_add_port(gpio, np, offs++);
+ if (err)
+ goto out_unregister;
+ }
+ platform_set_drvdata(pdev, gpio);
+
+ return 0;
+
+out_unregister:
+ dwapb_gpio_unregister(gpio);
+ dwapb_irq_teardown(gpio);
+
+out_err:
+ return err;
+}
+
+static int dwapb_gpio_remove(struct platform_device *pdev)
+{
+ struct dwapb_gpio *gpio = platform_get_drvdata(pdev);
+
+ dwapb_gpio_unregister(gpio);
+ dwapb_irq_teardown(gpio);
+
+ return 0;
+}
+
+static const struct of_device_id dwapb_of_match[] = {
+ { .compatible = "snps,dw-apb-gpio" },
+ { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, dwapb_of_match);
+
+static struct platform_driver dwapb_gpio_driver = {
+ .driver = {
+ .name = "gpio-dwapb",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(dwapb_of_match),
+ },
+ .probe = dwapb_gpio_probe,
+ .remove = dwapb_gpio_remove,
+};
+
+module_platform_driver(dwapb_gpio_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jamie Iles");
+MODULE_DESCRIPTION("Synopsys DesignWare APB GPIO driver");
--
1.7.9.5


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