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path: root/drivers/reset/reset-zx2967.c
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Diffstat (limited to 'drivers/reset/reset-zx2967.c')
-rw-r--r--drivers/reset/reset-zx2967.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/drivers/reset/reset-zx2967.c b/drivers/reset/reset-zx2967.c
new file mode 100644
index 000000000000..4dabb9ec4841
--- /dev/null
+++ b/drivers/reset/reset-zx2967.c
@@ -0,0 +1,99 @@
+/*
+ * ZTE's zx2967 family reset controller driver
+ *
+ * Copyright (C) 2017 ZTE Ltd.
+ *
+ * Author: Baoyou Xie <baoyou.xie@linaro.org>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+
+struct zx2967_reset {
+ void __iomem *reg_base;
+ spinlock_t lock;
+ struct reset_controller_dev rcdev;
+};
+
+static int zx2967_reset_act(struct reset_controller_dev *rcdev,
+ unsigned long id, bool assert)
+{
+ struct zx2967_reset *reset = NULL;
+ int bank = id / 32;
+ int offset = id % 32;
+ u32 reg;
+ unsigned long flags;
+
+ reset = container_of(rcdev, struct zx2967_reset, rcdev);
+
+ spin_lock_irqsave(&reset->lock, flags);
+
+ reg = readl_relaxed(reset->reg_base + (bank * 4));
+ if (assert)
+ reg &= ~BIT(offset);
+ else
+ reg |= BIT(offset);
+ writel_relaxed(reg, reset->reg_base + (bank * 4));
+
+ spin_unlock_irqrestore(&reset->lock, flags);
+
+ return 0;
+}
+
+static int zx2967_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return zx2967_reset_act(rcdev, id, true);
+}
+
+static int zx2967_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return zx2967_reset_act(rcdev, id, false);
+}
+
+static struct reset_control_ops zx2967_reset_ops = {
+ .assert = zx2967_reset_assert,
+ .deassert = zx2967_reset_deassert,
+};
+
+static int zx2967_reset_probe(struct platform_device *pdev)
+{
+ struct zx2967_reset *reset;
+ struct resource *res;
+
+ reset = devm_kzalloc(&pdev->dev, sizeof(*reset), GFP_KERNEL);
+ if (!reset)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ reset->reg_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(reset->reg_base))
+ return PTR_ERR(reset->reg_base);
+
+ spin_lock_init(&reset->lock);
+
+ reset->rcdev.owner = THIS_MODULE;
+ reset->rcdev.nr_resets = resource_size(res) * 8;
+ reset->rcdev.ops = &zx2967_reset_ops;
+ reset->rcdev.of_node = pdev->dev.of_node;
+
+ return devm_reset_controller_register(&pdev->dev, &reset->rcdev);
+}
+
+static const struct of_device_id zx2967_reset_dt_ids[] = {
+ { .compatible = "zte,zx296718-reset", },
+ {},
+};
+
+static struct platform_driver zx2967_reset_driver = {
+ .probe = zx2967_reset_probe,
+ .driver = {
+ .name = "zx2967-reset",
+ .of_match_table = zx2967_reset_dt_ids,
+ },
+};
+builtin_platform_driver(zx2967_reset_driver);