gpio: Add APM X-Gene SoC GPIO controller support

Add APM X-Gene SoC gpio controller driver.

Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 250 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-xgene.c b/drivers/gpio/gpio-xgene.c
new file mode 100644
index 000000000000..e25ba14fbb64
--- /dev/null
+++ b/drivers/gpio/gpio-xgene.c
@@ -0,0 +1,250 @@
+/*
+ * AppliedMicro X-Gene SoC GPIO Driver
+ *
+ * Copyright (c) 2014, Applied Micro Circuits Corporation
+ * Author: Feng Kan <fkan@apm.com>.
+ *
+ * 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.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/gpio/driver.h>
+#include <linux/types.h>
+#include <linux/bitops.h>
+
+#define GPIO_SET_DR_OFFSET      0x0C
+#define GPIO_DATA_OFFSET        0x14
+#define GPIO_BANK_STRIDE        0x0C
+
+#define XGENE_GPIOS_PER_BANK    16
+#define XGENE_MAX_GPIO_BANKS    3
+#define XGENE_MAX_GPIOS         (XGENE_GPIOS_PER_BANK * XGENE_MAX_GPIO_BANKS)
+
+#define GPIO_BIT_OFFSET(x)      (x % XGENE_GPIOS_PER_BANK)
+#define GPIO_BANK_OFFSET(x)     ((x / XGENE_GPIOS_PER_BANK) * GPIO_BANK_STRIDE)
+
+struct xgene_gpio;
+
+struct xgene_gpio {
+        struct gpio_chip        chip;
+        void __iomem            *base;
+        spinlock_t              lock;
+#ifdef CONFIG_PM
+        u32                     set_dr_val[XGENE_MAX_GPIO_BANKS];
+#endif
+};
+
+static inline struct xgene_gpio *to_xgene_gpio(struct gpio_chip *chip)
+{
+        return container_of(chip, struct xgene_gpio, chip);
+}
+
+static int xgene_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+        struct xgene_gpio *chip = to_xgene_gpio(gc);
+        unsigned long bank_offset;
+        u32 bit_offset;
+
+        bank_offset = GPIO_DATA_OFFSET + GPIO_BANK_OFFSET(offset);
+        bit_offset = GPIO_BIT_OFFSET(offset);
+        return !!(ioread32(chip->base + bank_offset) & BIT(bit_offset));
+}
+
+static void __xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
+{
+        struct xgene_gpio *chip = to_xgene_gpio(gc);
+        unsigned long bank_offset;
+        u32 setval, bit_offset;
+
+        bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
+        bit_offset = GPIO_BIT_OFFSET(offset) + XGENE_GPIOS_PER_BANK;
+
+        setval = ioread32(chip->base + bank_offset);
+        if (val)
+                setval |= BIT(bit_offset);
+        else
+                setval &= ~BIT(bit_offset);
+        iowrite32(setval, chip->base + bank_offset);
+}
+
+static void xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
+{
+        struct xgene_gpio *chip = to_xgene_gpio(gc);
+        unsigned long flags;
+
+        spin_lock_irqsave(&chip->lock, flags);
+        __xgene_gpio_set(gc, offset, val);
+        spin_unlock_irqrestore(&chip->lock, flags);
+}
+
+static int xgene_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
+{
+        struct xgene_gpio *chip = to_xgene_gpio(gc);
+        unsigned long flags, bank_offset;
+        u32 dirval, bit_offset;
+
+        bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
+        bit_offset = GPIO_BIT_OFFSET(offset);
+
+        spin_lock_irqsave(&chip->lock, flags);
+
+        dirval = ioread32(chip->base + bank_offset);
+        dirval |= BIT(bit_offset);
+        iowrite32(dirval, chip->base + bank_offset);
+
+        spin_unlock_irqrestore(&chip->lock, flags);
+
+        return 0;
+}
+
+static int xgene_gpio_dir_out(struct gpio_chip *gc,
+                                        unsigned int offset, int val)
+{
+        struct xgene_gpio *chip = to_xgene_gpio(gc);
+        unsigned long flags, bank_offset;
+        u32 dirval, bit_offset;
+
+        bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
+        bit_offset = GPIO_BIT_OFFSET(offset);
+
+        spin_lock_irqsave(&chip->lock, flags);
+
+        dirval = ioread32(chip->base + bank_offset);
+        dirval &= ~BIT(bit_offset);
+        iowrite32(dirval, chip->base + bank_offset);
+        __xgene_gpio_set(gc, offset, val);
+
+        spin_unlock_irqrestore(&chip->lock, flags);
+
+        return 0;
+}
+
+#ifdef CONFIG_PM
+static int xgene_gpio_suspend(struct device *dev)
+{
+        struct xgene_gpio *gpio = dev_get_drvdata(dev);
+        unsigned long bank_offset;
+        unsigned int bank;
+
+        for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
+                bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
+                gpio->set_dr_val[bank] = ioread32(gpio->base + bank_offset);
+        }
+        return 0;
+}
+
+static int xgene_gpio_resume(struct device *dev)
+{
+        struct xgene_gpio *gpio = dev_get_drvdata(dev);
+        unsigned long bank_offset;
+        unsigned int bank;
+
+        for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
+                bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
+                iowrite32(gpio->set_dr_val[bank], gpio->base + bank_offset);
+        }
+        return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(xgene_gpio_pm, xgene_gpio_suspend, xgene_gpio_resume);
+#define XGENE_GPIO_PM_OPS       (&xgene_gpio_pm)
+#else
+#define XGENE_GPIO_PM_OPS       NULL
+#endif
+
+static int xgene_gpio_probe(struct platform_device *pdev)
+{
+        struct resource *res;
+        struct xgene_gpio *gpio;
+        int err = 0;
+
+        gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
+        if (!gpio) {
+                err = -ENOMEM;
+                goto err;
+        }
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        gpio->base = devm_ioremap_nocache(&pdev->dev, res->start,
+                                                        resource_size(res));
+        if (IS_ERR(gpio->base)) {
+                err = PTR_ERR(gpio->base);
+                goto err;
+        }
+
+        gpio->chip.ngpio = XGENE_MAX_GPIOS;
+
+        gpio->chip.dev = &pdev->dev;
+        gpio->chip.direction_input = xgene_gpio_dir_in;
+        gpio->chip.direction_output = xgene_gpio_dir_out;
+        gpio->chip.get = xgene_gpio_get;
+        gpio->chip.set = xgene_gpio_set;
+        gpio->chip.label = dev_name(&pdev->dev);
+        gpio->chip.base = -1;
+
+        platform_set_drvdata(pdev, gpio);
+
+        err = gpiochip_add(&gpio->chip);
+        if (err) {
+                dev_err(&pdev->dev,
+                        "failed to register gpiochip.\n");
+                goto err;
+        }
+
+        dev_info(&pdev->dev, "X-Gene GPIO driver registered.\n");
+        return 0;
+err:
+        dev_err(&pdev->dev, "X-Gene GPIO driver registration failed.\n");
+        return err;
+}
+
+static int xgene_gpio_remove(struct platform_device *pdev)
+{
+        struct xgene_gpio *gpio = platform_get_drvdata(pdev);
+        int ret = 0;
+
+        ret = gpiochip_remove(&gpio->chip);
+        if (ret)
+                dev_err(&pdev->dev, "unable to remove gpio_chip.\n");
+        return ret;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id xgene_gpio_of_match[] = {
+        { .compatible = "apm,xgene-gpio", },
+        {},
+};
+MODULE_DEVICE_TABLE(of, xgene_gpio_of_match);
+#endif
+
+static struct platform_driver xgene_gpio_driver = {
+        .driver = {
+                .name = "xgene-gpio",
+                .owner = THIS_MODULE,
+                .of_match_table = xgene_gpio_of_match,
+                .pm     = XGENE_GPIO_PM_OPS,
+        },
+        .probe = xgene_gpio_probe,
+        .remove = xgene_gpio_remove,
+};
+
+module_platform_driver(xgene_gpio_driver);
+
+MODULE_AUTHOR("Feng Kan <fkan@apm.com>");
+MODULE_DESCRIPTION("APM X-Gene GPIO driver");
+MODULE_LICENSE("GPL");