gpio: Emma Mobile GPIO driver V2

This patch is V2 of the Emma Mobile GPIO driver. This
driver is designed to be reusable between multiple SoCs
that share the same basic building block, but so far it
has only been used on Emma Mobile EV2.

Each driver instance handles 32 GPIOs with individually
maskable IRQs. The driver operates on two I/O memory
ranges and the 32 GPIOs are hooked up to two interrupts.

In the case of Emma Mobile EV2 this GPIO building block
is used as main external interrupt controller hooking up
159 GPIOS as 159 interrupts via 5 driver instances and
10 interrupts to the GIC and the Cortex-A9 Dual.

Signed-off-by: Magnus Damm <damm@opensource.se>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

3 files changed, 425 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e03653d69357..eb80ba300452 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -91,6 +91,12 @@ config GPIO_IT8761E
         help
           Say yes here to support GPIO functionality of IT8761E super I/O chip.
 
+config GPIO_EM
+        tristate "Emma Mobile GPIO"
+        depends on ARM
+        help
+          Say yes here to support GPIO on Renesas Emma Mobile SoCs.
+
 config GPIO_EP93XX
         def_bool y
         depends on ARCH_EP93XX
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 007f54bd0081..3f1f829260bb 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_GPIO_BT8XX)	+= gpio-bt8xx.o
 obj-$(CONFIG_GPIO_CS5535)       += gpio-cs5535.o
 obj-$(CONFIG_GPIO_DA9052)       += gpio-da9052.o
 obj-$(CONFIG_ARCH_DAVINCI)      += gpio-davinci.o
+obj-$(CONFIG_GPIO_EM)           += gpio-em.o
 obj-$(CONFIG_GPIO_EP93XX)       += gpio-ep93xx.o
 obj-$(CONFIG_GPIO_GE_FPGA)      += gpio-ge.o
 obj-$(CONFIG_GPIO_IT8761E)      += gpio-it8761e.o
diff --git a/drivers/gpio/gpio-em.c b/drivers/gpio/gpio-em.c
new file mode 100644
index 000000000000..150d9768811d
--- /dev/null
+++ b/drivers/gpio/gpio-em.c
@@ -0,0 +1,418 @@
+/*
+ * Emma Mobile GPIO Support - GIO
+ *
+ *  Copyright (C) 2012 Magnus Damm
+ *
+ * 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
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/platform_data/gpio-em.h>
+
+struct em_gio_priv {
+        void __iomem *base0;
+        void __iomem *base1;
+        unsigned int irq_base;
+        spinlock_t sense_lock;
+        struct platform_device *pdev;
+        struct gpio_chip gpio_chip;
+        struct irq_chip irq_chip;
+        struct irq_domain *irq_domain;
+};
+
+#define GIO_E1 0x00
+#define GIO_E0 0x04
+#define GIO_EM 0x04
+#define GIO_OL 0x08
+#define GIO_OH 0x0c
+#define GIO_I 0x10
+#define GIO_IIA 0x14
+#define GIO_IEN 0x18
+#define GIO_IDS 0x1c
+#define GIO_IIM 0x1c
+#define GIO_RAW 0x20
+#define GIO_MST 0x24
+#define GIO_IIR 0x28
+
+#define GIO_IDT0 0x40
+#define GIO_IDT1 0x44
+#define GIO_IDT2 0x48
+#define GIO_IDT3 0x4c
+#define GIO_RAWBL 0x50
+#define GIO_RAWBH 0x54
+#define GIO_IRBL 0x58
+#define GIO_IRBH 0x5c
+
+#define GIO_IDT(n) (GIO_IDT0 + ((n) * 4))
+
+static inline unsigned long em_gio_read(struct em_gio_priv *p, int offs)
+{
+        if (offs < GIO_IDT0)
+                return ioread32(p->base0 + offs);
+        else
+                return ioread32(p->base1 + (offs - GIO_IDT0));
+}
+
+static inline void em_gio_write(struct em_gio_priv *p, int offs,
+                                unsigned long value)
+{
+        if (offs < GIO_IDT0)
+                iowrite32(value, p->base0 + offs);
+        else
+                iowrite32(value, p->base1 + (offs - GIO_IDT0));
+}
+
+static inline struct em_gio_priv *irq_to_priv(struct irq_data *d)
+{
+        struct irq_chip *chip = irq_data_get_irq_chip(d);
+        return container_of(chip, struct em_gio_priv, irq_chip);
+}
+
+static void em_gio_irq_disable(struct irq_data *d)
+{
+        struct em_gio_priv *p = irq_to_priv(d);
+
+        em_gio_write(p, GIO_IDS, BIT(irqd_to_hwirq(d)));
+}
+
+static void em_gio_irq_enable(struct irq_data *d)
+{
+        struct em_gio_priv *p = irq_to_priv(d);
+
+        em_gio_write(p, GIO_IEN, BIT(irqd_to_hwirq(d)));
+}
+
+#define GIO_ASYNC(x) (x + 8)
+
+static unsigned char em_gio_sense_table[IRQ_TYPE_SENSE_MASK + 1] = {
+        [IRQ_TYPE_EDGE_RISING] = GIO_ASYNC(0x00),
+        [IRQ_TYPE_EDGE_FALLING] = GIO_ASYNC(0x01),
+        [IRQ_TYPE_LEVEL_HIGH] = GIO_ASYNC(0x02),
+        [IRQ_TYPE_LEVEL_LOW] = GIO_ASYNC(0x03),
+        [IRQ_TYPE_EDGE_BOTH] = GIO_ASYNC(0x04),
+};
+
+static int em_gio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+        unsigned char value = em_gio_sense_table[type & IRQ_TYPE_SENSE_MASK];
+        struct em_gio_priv *p = irq_to_priv(d);
+        unsigned int reg, offset, shift;
+        unsigned long flags;
+        unsigned long tmp;
+
+        if (!value)
+                return -EINVAL;
+
+        offset = irqd_to_hwirq(d);
+
+        pr_debug("gio: sense irq = %d, mode = %d\n", offset, value);
+
+        /* 8 x 4 bit fields in 4 IDT registers */
+        reg = GIO_IDT(offset >> 3);
+        shift = (offset & 0x07) << 4;
+
+        spin_lock_irqsave(&p->sense_lock, flags);
+
+        /* disable the interrupt in IIA */
+        tmp = em_gio_read(p, GIO_IIA);
+        tmp &= ~BIT(offset);
+        em_gio_write(p, GIO_IIA, tmp);
+
+        /* change the sense setting in IDT */
+        tmp = em_gio_read(p, reg);
+        tmp &= ~(0xf << shift);
+        tmp |= value << shift;
+        em_gio_write(p, reg, tmp);
+
+        /* clear pending interrupts */
+        em_gio_write(p, GIO_IIR, BIT(offset));
+
+        /* enable the interrupt in IIA */
+        tmp = em_gio_read(p, GIO_IIA);
+        tmp |= BIT(offset);
+        em_gio_write(p, GIO_IIA, tmp);
+
+        spin_unlock_irqrestore(&p->sense_lock, flags);
+
+        return 0;
+}
+
+static irqreturn_t em_gio_irq_handler(int irq, void *dev_id)
+{
+        struct em_gio_priv *p = dev_id;
+        unsigned long pending;
+        unsigned int offset, irqs_handled = 0;
+
+        while ((pending = em_gio_read(p, GIO_MST))) {
+                offset = __ffs(pending);
+                em_gio_write(p, GIO_IIR, BIT(offset));
+                generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
+                irqs_handled++;
+        }
+
+        return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static inline struct em_gio_priv *gpio_to_priv(struct gpio_chip *chip)
+{
+        return container_of(chip, struct em_gio_priv, gpio_chip);
+}
+
+static int em_gio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+        em_gio_write(gpio_to_priv(chip), GIO_E0, BIT(offset));
+        return 0;
+}
+
+static int em_gio_get(struct gpio_chip *chip, unsigned offset)
+{
+        return (int)(em_gio_read(gpio_to_priv(chip), GIO_I) & BIT(offset));
+}
+
+static void __em_gio_set(struct gpio_chip *chip, unsigned int reg,
+                         unsigned shift, int value)
+{
+        /* upper 16 bits contains mask and lower 16 actual value */
+        em_gio_write(gpio_to_priv(chip), reg,
+                     (1 << (shift + 16)) | (value << shift));
+}
+
+static void em_gio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+        /* output is split into two registers */
+        if (offset < 16)
+                __em_gio_set(chip, GIO_OL, offset, value);
+        else
+                __em_gio_set(chip, GIO_OH, offset - 16, value);
+}
+
+static int em_gio_direction_output(struct gpio_chip *chip, unsigned offset,
+                                   int value)
+{
+        /* write GPIO value to output before selecting output mode of pin */
+        em_gio_set(chip, offset, value);
+        em_gio_write(gpio_to_priv(chip), GIO_E1, BIT(offset));
+        return 0;
+}
+
+static int em_gio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+        return irq_find_mapping(gpio_to_priv(chip)->irq_domain, offset);
+}
+
+static int em_gio_irq_domain_map(struct irq_domain *h, unsigned int virq,
+                                 irq_hw_number_t hw)
+{
+        struct em_gio_priv *p = h->host_data;
+
+        pr_debug("gio: map hw irq = %d, virq = %d\n", (int)hw, virq);
+
+        irq_set_chip_data(virq, h->host_data);
+        irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
+        set_irq_flags(virq, IRQF_VALID); /* kill me now */
+        return 0;
+}
+
+static struct irq_domain_ops em_gio_irq_domain_ops = {
+        .map    = em_gio_irq_domain_map,
+};
+
+static int __devinit em_gio_irq_domain_init(struct em_gio_priv *p)
+{
+        struct platform_device *pdev = p->pdev;
+        struct gpio_em_config *pdata = pdev->dev.platform_data;
+
+        p->irq_base = irq_alloc_descs(pdata->irq_base, 0,
+                                      pdata->number_of_pins, numa_node_id());
+        if (IS_ERR_VALUE(p->irq_base)) {
+                dev_err(&pdev->dev, "cannot get irq_desc\n");
+                return -ENXIO;
+        }
+        pr_debug("gio: hw base = %d, nr = %d, sw base = %d\n",
+                 pdata->gpio_base, pdata->number_of_pins, p->irq_base);
+
+        p->irq_domain = irq_domain_add_legacy(pdev->dev.of_node,
+                                              pdata->number_of_pins,
+                                              p->irq_base, 0,
+                                              &em_gio_irq_domain_ops, p);
+        if (!p->irq_domain) {
+                irq_free_descs(p->irq_base, pdata->number_of_pins);
+                return -ENXIO;
+        }
+
+        return 0;
+}
+
+static void __devexit em_gio_irq_domain_cleanup(struct em_gio_priv *p)
+{
+        struct gpio_em_config *pdata = p->pdev->dev.platform_data;
+
+        irq_free_descs(p->irq_base, pdata->number_of_pins);
+        /* FIXME: irq domain wants to be freed! */
+}
+
+static int __devinit em_gio_probe(struct platform_device *pdev)
+{
+        struct gpio_em_config *pdata = pdev->dev.platform_data;
+        struct em_gio_priv *p;
+        struct resource *io[2], *irq[2];
+        struct gpio_chip *gpio_chip;
+        struct irq_chip *irq_chip;
+        const char *name = dev_name(&pdev->dev);
+        int ret;
+
+        p = kzalloc(sizeof(*p), GFP_KERNEL);
+        if (!p) {
+                dev_err(&pdev->dev, "failed to allocate driver data\n");
+                ret = -ENOMEM;
+                goto err0;
+        }
+
+        p->pdev = pdev;
+        platform_set_drvdata(pdev, p);
+        spin_lock_init(&p->sense_lock);
+
+        io[0] = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        io[1] = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+        irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+        irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
+
+        if (!io[0] || !io[1] || !irq[0] || !irq[1] || !pdata) {
+                dev_err(&pdev->dev, "missing IRQ, IOMEM or configuration\n");
+                ret = -EINVAL;
+                goto err1;
+        }
+
+        p->base0 = ioremap_nocache(io[0]->start, resource_size(io[0]));
+        if (!p->base0) {
+                dev_err(&pdev->dev, "failed to remap low I/O memory\n");
+                ret = -ENXIO;
+                goto err1;
+        }
+
+        p->base1 = ioremap_nocache(io[1]->start, resource_size(io[1]));
+        if (!p->base1) {
+                dev_err(&pdev->dev, "failed to remap high I/O memory\n");
+                ret = -ENXIO;
+                goto err2;
+        }
+
+        gpio_chip = &p->gpio_chip;
+        gpio_chip->direction_input = em_gio_direction_input;
+        gpio_chip->get = em_gio_get;
+        gpio_chip->direction_output = em_gio_direction_output;
+        gpio_chip->set = em_gio_set;
+        gpio_chip->to_irq = em_gio_to_irq;
+        gpio_chip->label = name;
+        gpio_chip->owner = THIS_MODULE;
+        gpio_chip->base = pdata->gpio_base;
+        gpio_chip->ngpio = pdata->number_of_pins;
+
+        irq_chip = &p->irq_chip;
+        irq_chip->name = name;
+        irq_chip->irq_mask = em_gio_irq_disable;
+        irq_chip->irq_unmask = em_gio_irq_enable;
+        irq_chip->irq_enable = em_gio_irq_enable;
+        irq_chip->irq_disable = em_gio_irq_disable;
+        irq_chip->irq_set_type = em_gio_irq_set_type;
+        irq_chip->flags = IRQCHIP_SKIP_SET_WAKE;
+
+        ret = em_gio_irq_domain_init(p);
+        if (ret) {
+                dev_err(&pdev->dev, "cannot initialize irq domain\n");
+                goto err3;
+        }
+
+        if (request_irq(irq[0]->start, em_gio_irq_handler, 0, name, p)) {
+                dev_err(&pdev->dev, "failed to request low IRQ\n");
+                ret = -ENOENT;
+                goto err4;
+        }
+
+        if (request_irq(irq[1]->start, em_gio_irq_handler, 0, name, p)) {
+                dev_err(&pdev->dev, "failed to request high IRQ\n");
+                ret = -ENOENT;
+                goto err5;
+        }
+
+        ret = gpiochip_add(gpio_chip);
+        if (ret) {
+                dev_err(&pdev->dev, "failed to add GPIO controller\n");
+                goto err6;
+        }
+        return 0;
+
+err6:
+        free_irq(irq[1]->start, pdev);
+err5:
+        free_irq(irq[0]->start, pdev);
+err4:
+        em_gio_irq_domain_cleanup(p);
+err3:
+        iounmap(p->base1);
+err2:
+        iounmap(p->base0);
+err1:
+        kfree(p);
+err0:
+        return ret;
+}
+
+static int __devexit em_gio_remove(struct platform_device *pdev)
+{
+        struct em_gio_priv *p = platform_get_drvdata(pdev);
+        struct resource *irq[2];
+        int ret;
+
+        ret = gpiochip_remove(&p->gpio_chip);
+        if (ret)
+                return ret;
+
+        irq[0] = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+        irq[1] = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
+
+        free_irq(irq[1]->start, pdev);
+        free_irq(irq[0]->start, pdev);
+        em_gio_irq_domain_cleanup(p);
+        iounmap(p->base1);
+        iounmap(p->base0);
+        kfree(p);
+        return 0;
+}
+
+static struct platform_driver em_gio_device_driver = {
+        .probe          = em_gio_probe,
+        .remove         = __devexit_p(em_gio_remove),
+        .driver         = {
+                .name   = "em_gio",
+        }
+};
+
+module_platform_driver(em_gio_device_driver);
+
+MODULE_AUTHOR("Magnus Damm");
+MODULE_DESCRIPTION("Renesas Emma Mobile GIO Driver");
+MODULE_LICENSE("GPL v2");