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path: root/drivers/reset/reset-ath79.c
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Diffstat (limited to 'drivers/reset/reset-ath79.c')
-rw-r--r--drivers/reset/reset-ath79.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/drivers/reset/reset-ath79.c b/drivers/reset/reset-ath79.c
new file mode 100644
index 0000000000..b5d6201320
--- /dev/null
+++ b/drivers/reset/reset-ath79.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * AR71xx Reset Controller Driver
+ * Author: Alban Bedel
+ *
+ * Copyright (C) 2015 Alban Bedel <albeu@free.fr>
+ */
+
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/reboot.h>
+
+struct ath79_reset {
+ struct reset_controller_dev rcdev;
+ struct notifier_block restart_nb;
+ void __iomem *base;
+ spinlock_t lock;
+};
+
+#define FULL_CHIP_RESET 24
+
+static int ath79_reset_update(struct reset_controller_dev *rcdev,
+ unsigned long id, bool assert)
+{
+ struct ath79_reset *ath79_reset =
+ container_of(rcdev, struct ath79_reset, rcdev);
+ unsigned long flags;
+ u32 val;
+
+ spin_lock_irqsave(&ath79_reset->lock, flags);
+ val = readl(ath79_reset->base);
+ if (assert)
+ val |= BIT(id);
+ else
+ val &= ~BIT(id);
+ writel(val, ath79_reset->base);
+ spin_unlock_irqrestore(&ath79_reset->lock, flags);
+
+ return 0;
+}
+
+static int ath79_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return ath79_reset_update(rcdev, id, true);
+}
+
+static int ath79_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return ath79_reset_update(rcdev, id, false);
+}
+
+static int ath79_reset_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct ath79_reset *ath79_reset =
+ container_of(rcdev, struct ath79_reset, rcdev);
+ u32 val;
+
+ val = readl(ath79_reset->base);
+
+ return !!(val & BIT(id));
+}
+
+static const struct reset_control_ops ath79_reset_ops = {
+ .assert = ath79_reset_assert,
+ .deassert = ath79_reset_deassert,
+ .status = ath79_reset_status,
+};
+
+static int ath79_reset_restart_handler(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct ath79_reset *ath79_reset =
+ container_of(nb, struct ath79_reset, restart_nb);
+
+ ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);
+
+ return NOTIFY_DONE;
+}
+
+static int ath79_reset_probe(struct platform_device *pdev)
+{
+ struct ath79_reset *ath79_reset;
+ int err;
+
+ ath79_reset = devm_kzalloc(&pdev->dev,
+ sizeof(*ath79_reset), GFP_KERNEL);
+ if (!ath79_reset)
+ return -ENOMEM;
+
+ ath79_reset->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(ath79_reset->base))
+ return PTR_ERR(ath79_reset->base);
+
+ spin_lock_init(&ath79_reset->lock);
+ ath79_reset->rcdev.ops = &ath79_reset_ops;
+ ath79_reset->rcdev.owner = THIS_MODULE;
+ ath79_reset->rcdev.of_node = pdev->dev.of_node;
+ ath79_reset->rcdev.of_reset_n_cells = 1;
+ ath79_reset->rcdev.nr_resets = 32;
+
+ err = devm_reset_controller_register(&pdev->dev, &ath79_reset->rcdev);
+ if (err)
+ return err;
+
+ ath79_reset->restart_nb.notifier_call = ath79_reset_restart_handler;
+ ath79_reset->restart_nb.priority = 128;
+
+ err = register_restart_handler(&ath79_reset->restart_nb);
+ if (err)
+ dev_warn(&pdev->dev, "Failed to register restart handler\n");
+
+ return 0;
+}
+
+static const struct of_device_id ath79_reset_dt_ids[] = {
+ { .compatible = "qca,ar7100-reset", },
+ { },
+};
+
+static struct platform_driver ath79_reset_driver = {
+ .probe = ath79_reset_probe,
+ .driver = {
+ .name = "ath79-reset",
+ .of_match_table = ath79_reset_dt_ids,
+ .suppress_bind_attrs = true,
+ },
+};
+builtin_platform_driver(ath79_reset_driver);