summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-loongson1.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/gpio/gpio-loongson1.c')
-rw-r--r--drivers/gpio/gpio-loongson1.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-loongson1.c b/drivers/gpio/gpio-loongson1.c
new file mode 100644
index 0000000000..6ca3b969db
--- /dev/null
+++ b/drivers/gpio/gpio-loongson1.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * GPIO Driver for Loongson 1 SoC
+ *
+ * Copyright (C) 2015-2023 Keguang Zhang <keguang.zhang@gmail.com>
+ */
+
+#include <linux/module.h>
+#include <linux/gpio/driver.h>
+#include <linux/platform_device.h>
+#include <linux/bitops.h>
+
+/* Loongson 1 GPIO Register Definitions */
+#define GPIO_CFG 0x0
+#define GPIO_DIR 0x10
+#define GPIO_DATA 0x20
+#define GPIO_OUTPUT 0x30
+
+struct ls1x_gpio_chip {
+ struct gpio_chip gc;
+ void __iomem *reg_base;
+};
+
+static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset)
+{
+ struct ls1x_gpio_chip *ls1x_gc = gpiochip_get_data(gc);
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
+ __raw_writel(__raw_readl(ls1x_gc->reg_base + GPIO_CFG) | BIT(offset),
+ ls1x_gc->reg_base + GPIO_CFG);
+ raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+
+ return 0;
+}
+
+static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset)
+{
+ struct ls1x_gpio_chip *ls1x_gc = gpiochip_get_data(gc);
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
+ __raw_writel(__raw_readl(ls1x_gc->reg_base + GPIO_CFG) & ~BIT(offset),
+ ls1x_gc->reg_base + GPIO_CFG);
+ raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
+}
+
+static int ls1x_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ls1x_gpio_chip *ls1x_gc;
+ int ret;
+
+ ls1x_gc = devm_kzalloc(dev, sizeof(*ls1x_gc), GFP_KERNEL);
+ if (!ls1x_gc)
+ return -ENOMEM;
+
+ ls1x_gc->reg_base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(ls1x_gc->reg_base))
+ return PTR_ERR(ls1x_gc->reg_base);
+
+ ret = bgpio_init(&ls1x_gc->gc, dev, 4, ls1x_gc->reg_base + GPIO_DATA,
+ ls1x_gc->reg_base + GPIO_OUTPUT, NULL,
+ NULL, ls1x_gc->reg_base + GPIO_DIR, 0);
+ if (ret)
+ goto err;
+
+ ls1x_gc->gc.owner = THIS_MODULE;
+ ls1x_gc->gc.request = ls1x_gpio_request;
+ ls1x_gc->gc.free = ls1x_gpio_free;
+ /*
+ * Clear ngpio to let gpiolib get the correct number
+ * by reading ngpios property
+ */
+ ls1x_gc->gc.ngpio = 0;
+
+ ret = devm_gpiochip_add_data(dev, &ls1x_gc->gc, ls1x_gc);
+ if (ret)
+ goto err;
+
+ platform_set_drvdata(pdev, ls1x_gc);
+
+ dev_info(dev, "GPIO controller registered with %d pins\n",
+ ls1x_gc->gc.ngpio);
+
+ return 0;
+err:
+ dev_err(dev, "failed to register GPIO controller\n");
+ return ret;
+}
+
+static const struct of_device_id ls1x_gpio_dt_ids[] = {
+ { .compatible = "loongson,ls1x-gpio" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ls1x_gpio_dt_ids);
+
+static struct platform_driver ls1x_gpio_driver = {
+ .probe = ls1x_gpio_probe,
+ .driver = {
+ .name = "ls1x-gpio",
+ .of_match_table = ls1x_gpio_dt_ids,
+ },
+};
+
+module_platform_driver(ls1x_gpio_driver);
+
+MODULE_AUTHOR("Keguang Zhang <keguang.zhang@gmail.com>");
+MODULE_DESCRIPTION("Loongson1 GPIO driver");
+MODULE_LICENSE("GPL");