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authorAlban Bedel <albeu@free.fr>2015-08-03 19:23:52 +0200
committerPhilipp Zabel <p.zabel@pengutronix.de>2015-08-04 10:41:30 +0200
commitff591a91225d3621a503bb18faa0f0d747a06e50 (patch)
tree62b9ae2b8ca15b6e1a09c4a8e6b505bc674d1852 /drivers/reset/reset-ath79.c
parentf25b5edac7be7d405965fb68c6b6f65d8852d860 (diff)
reset: Add a driver for the reset controller on the AR71XX/AR9XXX
The AR71XX/AR9XXX SoC have a simple reset controller with one bit per reset line. Signed-off-by: Alban Bedel <albeu@free.fr> Acked-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Diffstat (limited to 'drivers/reset/reset-ath79.c')
-rw-r--r--drivers/reset/reset-ath79.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/drivers/reset/reset-ath79.c b/drivers/reset/reset-ath79.c
new file mode 100644
index 000000000000..d2d290413113
--- /dev/null
+++ b/drivers/reset/reset-ath79.c
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2015 Alban Bedel <albeu@free.fr>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+
+struct ath79_reset {
+ struct reset_controller_dev rcdev;
+ void __iomem *base;
+ spinlock_t lock;
+};
+
+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 struct reset_control_ops ath79_reset_ops = {
+ .assert = ath79_reset_assert,
+ .deassert = ath79_reset_deassert,
+ .status = ath79_reset_status,
+};
+
+static int ath79_reset_probe(struct platform_device *pdev)
+{
+ struct ath79_reset *ath79_reset;
+ struct resource *res;
+
+ ath79_reset = devm_kzalloc(&pdev->dev,
+ sizeof(*ath79_reset), GFP_KERNEL);
+ if (!ath79_reset)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, ath79_reset);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ath79_reset->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(ath79_reset->base))
+ return PTR_ERR(ath79_reset->base);
+
+ 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;
+
+ return reset_controller_register(&ath79_reset->rcdev);
+}
+
+static int ath79_reset_remove(struct platform_device *pdev)
+{
+ struct ath79_reset *ath79_reset = platform_get_drvdata(pdev);
+
+ reset_controller_unregister(&ath79_reset->rcdev);
+
+ return 0;
+}
+
+static const struct of_device_id ath79_reset_dt_ids[] = {
+ { .compatible = "qca,ar7100-reset", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ath79_reset_dt_ids);
+
+static struct platform_driver ath79_reset_driver = {
+ .probe = ath79_reset_probe,
+ .remove = ath79_reset_remove,
+ .driver = {
+ .name = "ath79-reset",
+ .of_match_table = ath79_reset_dt_ids,
+ },
+};
+module_platform_driver(ath79_reset_driver);
+
+MODULE_AUTHOR("Alban Bedel <albeu@free.fr>");
+MODULE_DESCRIPTION("AR71xx Reset Controller Driver");
+MODULE_LICENSE("GPL");

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