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path: root/drivers/gpio/gpio-loongson1.c
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Diffstat (limited to 'drivers/gpio/gpio-loongson1.c')
-rw-r--r--drivers/gpio/gpio-loongson1.c102
1 files changed, 102 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-loongson1.c b/drivers/gpio/gpio-loongson1.c
new file mode 100644
index 000000000..10c09bdd8
--- /dev/null
+++ b/drivers/gpio/gpio-loongson1.c
@@ -0,0 +1,102 @@
+/*
+ * GPIO Driver for Loongson 1 SoC
+ *
+ * Copyright (C) 2015-2016 Zhang, Keguang <keguang.zhang@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/platform_device.h>
+
+/* Loongson 1 GPIO Register Definitions */
+#define GPIO_CFG 0x0
+#define GPIO_DIR 0x10
+#define GPIO_DATA 0x20
+#define GPIO_OUTPUT 0x30
+
+static void __iomem *gpio_reg_base;
+
+static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset)
+{
+ unsigned long pinmask = gc->pin2mask(gc, offset);
+ unsigned long flags;
+
+ spin_lock_irqsave(&gc->bgpio_lock, flags);
+ __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) | pinmask,
+ gpio_reg_base + GPIO_CFG);
+ spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+
+ return 0;
+}
+
+static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset)
+{
+ unsigned long pinmask = gc->pin2mask(gc, offset);
+ unsigned long flags;
+
+ spin_lock_irqsave(&gc->bgpio_lock, flags);
+ __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) & ~pinmask,
+ gpio_reg_base + GPIO_CFG);
+ spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+}
+
+static int ls1x_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct gpio_chip *gc;
+ struct resource *res;
+ int ret;
+
+ gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
+ if (!gc)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "failed to get I/O memory\n");
+ return -EINVAL;
+ }
+
+ gpio_reg_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(gpio_reg_base))
+ return PTR_ERR(gpio_reg_base);
+
+ ret = bgpio_init(gc, dev, 4, gpio_reg_base + GPIO_DATA,
+ gpio_reg_base + GPIO_OUTPUT, NULL,
+ NULL, gpio_reg_base + GPIO_DIR, 0);
+ if (ret)
+ goto err;
+
+ gc->owner = THIS_MODULE;
+ gc->request = ls1x_gpio_request;
+ gc->free = ls1x_gpio_free;
+ gc->base = pdev->id * 32;
+
+ ret = devm_gpiochip_add_data(dev, gc, NULL);
+ if (ret)
+ goto err;
+
+ platform_set_drvdata(pdev, gc);
+ dev_info(dev, "Loongson1 GPIO driver registered\n");
+
+ return 0;
+err:
+ dev_err(dev, "failed to register GPIO device\n");
+ return ret;
+}
+
+static struct platform_driver ls1x_gpio_driver = {
+ .probe = ls1x_gpio_probe,
+ .driver = {
+ .name = "ls1x-gpio",
+ },
+};
+
+module_platform_driver(ls1x_gpio_driver);
+
+MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>");
+MODULE_DESCRIPTION("Loongson1 GPIO driver");
+MODULE_LICENSE("GPL");