[PATCH v2 1/3] ARM: meson: reset: Add reset controller for MesonX SoCs

Hi Carlo,

On Tue, Oct 14, 2014 at 08:35:47PM +0200, Carlo Caione wrote:

That doesn't sound right. Do you mean socfpga-reset?

+ * Copyright 2014 Steffen Trumtrar
+ *
+ * Steffen Trumtrar [off-list ref]

Could be combined into a single line.

+ * 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.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#define MESON_RST_OFFSET	0x00

If there is only one register, I see no need for this.

+struct meson_reset_data {
+	spinlock_t			lock;
+	void __iomem			*membase;
+	struct reset_controller_dev	rcdev;
+};
+
+static int meson_reset_assert(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	struct meson_reset_data *data = container_of(rcdev,
+						     struct meson_reset_data,
+						     rcdev);
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&data->lock, flags);
+
+	reg = readl(data->membase + MESON_RST_OFFSET);
+	writel(reg | BIT(id), data->membase + MESON_RST_OFFSET);
+
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return 0;
+}
+
+static int meson_reset_deassert(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	struct meson_reset_data *data = container_of(rcdev,
+						     struct meson_reset_data,
+						     rcdev);
+
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&data->lock, flags);
+
+	reg = readl(data->membase + MESON_RST_OFFSET);
+	writel(reg & ~BIT(id), data->membase + MESON_RST_OFFSET);
+
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return 0;
+}
+
+static int meson_reset_dev(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	int err;
+
+	err = meson_reset_assert(rcdev, id);
+	if (err)
+		return err;
+
+	return meson_reset_deassert(rcdev, id);
+}
+
+static struct reset_control_ops meson_reset_ops = {
+	.assert		= meson_reset_assert,
+	.deassert	= meson_reset_deassert,
+	.reset		= meson_reset_dev,
+};
+
+static int meson_reset_probe(struct platform_device *pdev)
+{
+	struct meson_reset_data *data;
+	struct resource *res;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->membase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(data->membase))
+		return PTR_ERR(data->membase);
+
+	spin_lock_init(&data->lock);
+
+	platform_set_drvdata(pdev, data);
+
+	data->rcdev.owner = THIS_MODULE;
+	data->rcdev.nr_resets = BITS_PER_LONG;

Are all bits in this registers reset controls (or rather, are you
positive there is no bit in this register used by anything else)?

+	data->rcdev.ops = &meson_reset_ops;
+	data->rcdev.of_node = pdev->dev.of_node;
+
+	return reset_controller_register(&data->rcdev);
+}
+
+static int meson_reset_remove(struct platform_device *pdev)
+{
+	struct meson_reset_data *data = platform_get_drvdata(pdev);
+
+	reset_controller_unregister(&data->rcdev);
+
+	return 0;
+}
+
+static const struct of_device_id meson_reset_dt_ids[] = {
+	{ .compatible = "amlogic,meson6-rst-mgr-ao", },
+	{ /* sentinel */ },
+};
+
+static struct platform_driver meson_reset_driver = {
+	.probe	= meson_reset_probe,
+	.remove	= meson_reset_remove,
+	.driver = {
+		.name		= "meson-reset",
+		.of_match_table	= meson_reset_dt_ids,
+	},
+};
+module_platform_driver(meson_reset_driver);
+
+MODULE_AUTHOR("Carlo Caione [off-list ref]");
+MODULE_DESCRIPTION("Meson Reset Controller Driver");
+MODULE_LICENSE("GPL");
-- 
1.9.1

Other than that, the driver looks good.

regards
Philipp