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path: root/drivers/gpio/gpio-xgene.c
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Diffstat (limited to 'drivers/gpio/gpio-xgene.c')
-rw-r--r--drivers/gpio/gpio-xgene.c244
1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-xgene.c b/drivers/gpio/gpio-xgene.c
new file mode 100644
index 000000000000..7d489221dc1f
--- /dev/null
+++ b/drivers/gpio/gpio-xgene.c
@@ -0,0 +1,244 @@
+/*
+ * 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 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 (!gpio->base) {
+ err = -ENOMEM;
+ goto err;
+ }
+
+ gpio->chip.ngpio = XGENE_MAX_GPIOS;
+
+ spin_lock_init(&gpio->lock);
+ 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);
+
+ gpiochip_remove(&gpio->chip);
+ return 0;
+}
+
+static const struct of_device_id xgene_gpio_of_match[] = {
+ { .compatible = "apm,xgene-gpio", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, xgene_gpio_of_match);
+
+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");
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