gpio: vf610: add gpiolib/IRQ chip driver for Vybrid

Add a gpiolib and IRQ chip driver for Vybrid ARM SoC using the
Vybrid's GPIO and PORT module. The driver is instanced once per
each GPIO/PORT module pair and handles 32 GPIO's.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

3 files changed, 303 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index cd3313436b3a..690ad0b20414 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -347,6 +347,13 @@ config GPIO_TZ1090_PDC
         help
           Say yes here to support Toumaz Xenif TZ1090 PDC GPIOs.
 
+config GPIO_VF610
+        def_bool y
+        depends on ARCH_MXC && SOC_VF610
+        select GPIOLIB_IRQCHIP
+        help
+          Say yes here to support Vybrid vf610 GPIOs.
+
 config GPIO_XGENE
         bool "APM X-Gene GPIO controller support"
         depends on ARM64 && OF_GPIO
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 4486bbd2dad7..aaea751fa845 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -96,6 +96,7 @@ obj-$(CONFIG_GPIO_TWL6040)	+= gpio-twl6040.o
 obj-$(CONFIG_GPIO_TZ1090)       += gpio-tz1090.o
 obj-$(CONFIG_GPIO_TZ1090_PDC)   += gpio-tz1090-pdc.o
 obj-$(CONFIG_GPIO_UCB1400)      += gpio-ucb1400.o
+obj-$(CONFIG_GPIO_VF610)        += gpio-vf610.o
 obj-$(CONFIG_GPIO_VIPERBOARD)   += gpio-viperboard.o
 obj-$(CONFIG_GPIO_VR41XX)       += gpio-vr41xx.o
 obj-$(CONFIG_GPIO_VX855)        += gpio-vx855.o
diff --git a/drivers/gpio/gpio-vf610.c b/drivers/gpio/gpio-vf610.c
new file mode 100644
index 000000000000..4ee4cee832ec
--- /dev/null
+++ b/drivers/gpio/gpio-vf610.c
@@ -0,0 +1,295 @@
+/*
+ * vf610 GPIO support through PORT and GPIO module
+ *
+ * Copyright (c) 2014 Toradex AG.
+ *
+ * Author: Stefan Agner <stefan@agner.ch>.
+ *
+ * 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; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+
+#define VF610_GPIO_PER_PORT             32
+
+struct vf610_gpio_port {
+        struct gpio_chip gc;
+        void __iomem *base;
+        void __iomem *gpio_base;
+        u8 irqc[VF610_GPIO_PER_PORT];
+        int irq;
+};
+
+#define GPIO_PDOR               0x00
+#define GPIO_PSOR               0x04
+#define GPIO_PCOR               0x08
+#define GPIO_PTOR               0x0c
+#define GPIO_PDIR               0x10
+
+#define PORT_PCR(n)             ((n) * 0x4)
+#define PORT_PCR_IRQC_OFFSET    16
+
+#define PORT_ISFR               0xa0
+#define PORT_DFER               0xc0
+#define PORT_DFCR               0xc4
+#define PORT_DFWR               0xc8
+
+#define PORT_INT_OFF            0x0
+#define PORT_INT_LOGIC_ZERO     0x8
+#define PORT_INT_RISING_EDGE    0x9
+#define PORT_INT_FALLING_EDGE   0xa
+#define PORT_INT_EITHER_EDGE    0xb
+#define PORT_INT_LOGIC_ONE      0xc
+
+static const struct of_device_id vf610_gpio_dt_ids[] = {
+        { .compatible = "fsl,vf610-gpio" },
+        { /* sentinel */ }
+};
+
+static inline void vf610_gpio_writel(u32 val, void __iomem *reg)
+{
+        writel_relaxed(val, reg);
+}
+
+static inline u32 vf610_gpio_readl(void __iomem *reg)
+{
+        return readl_relaxed(reg);
+}
+
+static int vf610_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+        return pinctrl_request_gpio(chip->base + offset);
+}
+
+static void vf610_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+        pinctrl_free_gpio(chip->base + offset);
+}
+
+static int vf610_gpio_get(struct gpio_chip *gc, unsigned int gpio)
+{
+        struct vf610_gpio_port *port =
+                container_of(gc, struct vf610_gpio_port, gc);
+
+        return !!(vf610_gpio_readl(port->gpio_base + GPIO_PDIR) & BIT(gpio));
+}
+
+static void vf610_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+        struct vf610_gpio_port *port =
+                container_of(gc, struct vf610_gpio_port, gc);
+        unsigned long mask = BIT(gpio);
+
+        if (val)
+                vf610_gpio_writel(mask, port->gpio_base + GPIO_PSOR);
+        else
+                vf610_gpio_writel(mask, port->gpio_base + GPIO_PCOR);
+}
+
+static int vf610_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+{
+        return pinctrl_gpio_direction_input(chip->base + gpio);
+}
+
+static int vf610_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
+                                       int value)
+{
+        vf610_gpio_set(chip, gpio, value);
+
+        return pinctrl_gpio_direction_output(chip->base + gpio);
+}
+
+static void vf610_gpio_irq_handler(u32 irq, struct irq_desc *desc)
+{
+        struct vf610_gpio_port *port = irq_get_handler_data(irq);
+        struct irq_chip *chip = irq_desc_get_chip(desc);
+        int pin;
+        unsigned long irq_isfr;
+
+        chained_irq_enter(chip, desc);
+
+        irq_isfr = vf610_gpio_readl(port->base + PORT_ISFR);
+
+        for_each_set_bit(pin, &irq_isfr, VF610_GPIO_PER_PORT) {
+                vf610_gpio_writel(BIT(pin), port->base + PORT_ISFR);
+
+                generic_handle_irq(irq_find_mapping(port->gc.irqdomain, pin));
+        }
+
+        chained_irq_exit(chip, desc);
+}
+
+static void vf610_gpio_irq_ack(struct irq_data *d)
+{
+        struct vf610_gpio_port *port = irq_data_get_irq_chip_data(d);
+        int gpio = d->hwirq;
+
+        vf610_gpio_writel(BIT(gpio), port->base + PORT_ISFR);
+}
+
+static int vf610_gpio_irq_set_type(struct irq_data *d, u32 type)
+{
+        struct vf610_gpio_port *port = irq_data_get_irq_chip_data(d);
+        u8 irqc;
+
+        switch (type) {
+        case IRQ_TYPE_EDGE_RISING:
+                irqc = PORT_INT_RISING_EDGE;
+                break;
+        case IRQ_TYPE_EDGE_FALLING:
+                irqc = PORT_INT_FALLING_EDGE;
+                break;
+        case IRQ_TYPE_EDGE_BOTH:
+                irqc = PORT_INT_EITHER_EDGE;
+                break;
+        case IRQ_TYPE_LEVEL_LOW:
+                irqc = PORT_INT_LOGIC_ZERO;
+                break;
+        case IRQ_TYPE_LEVEL_HIGH:
+                irqc = PORT_INT_LOGIC_ONE;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        port->irqc[d->hwirq] = irqc;
+
+        return 0;
+}
+
+static void vf610_gpio_irq_mask(struct irq_data *d)
+{
+        struct vf610_gpio_port *port = irq_data_get_irq_chip_data(d);
+        void __iomem *pcr_base = port->base + PORT_PCR(d->hwirq);
+
+        vf610_gpio_writel(0, pcr_base);
+}
+
+static void vf610_gpio_irq_unmask(struct irq_data *d)
+{
+        struct vf610_gpio_port *port = irq_data_get_irq_chip_data(d);
+        void __iomem *pcr_base = port->base + PORT_PCR(d->hwirq);
+
+        vf610_gpio_writel(port->irqc[d->hwirq] << PORT_PCR_IRQC_OFFSET,
+                          pcr_base);
+}
+
+static int vf610_gpio_irq_set_wake(struct irq_data *d, u32 enable)
+{
+        struct vf610_gpio_port *port = irq_data_get_irq_chip_data(d);
+
+        if (enable)
+                enable_irq_wake(port->irq);
+        else
+                disable_irq_wake(port->irq);
+
+        return 0;
+}
+
+static struct irq_chip vf610_gpio_irq_chip = {
+        .name           = "gpio-vf610",
+        .irq_ack        = vf610_gpio_irq_ack,
+        .irq_mask       = vf610_gpio_irq_mask,
+        .irq_unmask     = vf610_gpio_irq_unmask,
+        .irq_set_type   = vf610_gpio_irq_set_type,
+        .irq_set_wake   = vf610_gpio_irq_set_wake,
+};
+
+static int vf610_gpio_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct device_node *np = dev->of_node;
+        struct vf610_gpio_port *port;
+        struct resource *iores;
+        struct gpio_chip *gc;
+        int ret;
+
+        port = devm_kzalloc(&pdev->dev, sizeof(*port), GFP_KERNEL);
+        if (!port)
+                return -ENOMEM;
+
+        iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        port->base = devm_ioremap_resource(dev, iores);
+        if (IS_ERR(port->base))
+                return PTR_ERR(port->base);
+
+        iores = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+        port->gpio_base = devm_ioremap_resource(dev, iores);
+        if (IS_ERR(port->gpio_base))
+                return PTR_ERR(port->gpio_base);
+
+        port->irq = platform_get_irq(pdev, 0);
+        if (port->irq < 0)
+                return port->irq;
+
+        gc = &port->gc;
+        gc->of_node = np;
+        gc->dev = dev;
+        gc->label = "vf610-gpio",
+        gc->ngpio = VF610_GPIO_PER_PORT,
+        gc->base = of_alias_get_id(np, "gpio") * VF610_GPIO_PER_PORT;
+
+        gc->request = vf610_gpio_request,
+        gc->free = vf610_gpio_free,
+        gc->direction_input = vf610_gpio_direction_input,
+        gc->get = vf610_gpio_get,
+        gc->direction_output = vf610_gpio_direction_output,
+        gc->set = vf610_gpio_set,
+
+        ret = gpiochip_add(gc);
+        if (ret < 0)
+                return ret;
+
+        /* Clear the interrupt status register for all GPIO's */
+        vf610_gpio_writel(~0, port->base + PORT_ISFR);
+
+        ret = gpiochip_irqchip_add(gc, &vf610_gpio_irq_chip, 0,
+                                   handle_simple_irq, IRQ_TYPE_NONE);
+        if (ret) {
+                dev_err(dev, "failed to add irqchip\n");
+                gpiochip_remove(gc);
+                return ret;
+        }
+        gpiochip_set_chained_irqchip(gc, &vf610_gpio_irq_chip, port->irq,
+                                     vf610_gpio_irq_handler);
+
+        return 0;
+}
+
+static struct platform_driver vf610_gpio_driver = {
+        .driver         = {
+                .name   = "gpio-vf610",
+                .owner  = THIS_MODULE,
+                .of_match_table = vf610_gpio_dt_ids,
+        },
+        .probe          = vf610_gpio_probe,
+};
+
+static int __init gpio_vf610_init(void)
+{
+        return platform_driver_register(&vf610_gpio_driver);
+}
+device_initcall(gpio_vf610_init);
+
+MODULE_AUTHOR("Stefan Agner <stefan@agner.ch>");
+MODULE_DESCRIPTION("Freescale VF610 GPIO");
+MODULE_LICENSE("GPL v2");