Merge branch 'torvalds/master'

[firefly-linux-kernel-4.4.55.git] / drivers / reset / reset-berlin.c

diff --git a/drivers/reset/reset-berlin.c b/drivers/reset/reset-berlin.c
new file mode 100644 (file)
index 0000000..3c922d3
--- /dev/null
+++ b/drivers/reset/reset-berlin.c
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2014 Marvell Technology Group Ltd.
+ *
+ * Antoine Tenart <antoine.tenart@free-electrons.com>
+ * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define BERLIN_MAX_RESETS      32
+
+#define to_berlin_reset_priv(p)                \
+       container_of((p), struct berlin_reset_priv, rcdev)
+
+struct berlin_reset_priv {
+       struct regmap                   *regmap;
+       struct reset_controller_dev     rcdev;
+};
+
+static int berlin_reset_reset(struct reset_controller_dev *rcdev,
+                             unsigned long id)
+{
+       struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);
+       int offset = id >> 8;
+       int mask = BIT(id & 0x1f);
+
+       regmap_write(priv->regmap, offset, mask);
+
+       /* let the reset be effective */
+       udelay(10);
+
+       return 0;
+}
+
+static struct reset_control_ops berlin_reset_ops = {
+       .reset  = berlin_reset_reset,
+};
+
+static int berlin_reset_xlate(struct reset_controller_dev *rcdev,
+                             const struct of_phandle_args *reset_spec)
+{
+       unsigned offset, bit;
+
+       if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
+               return -EINVAL;
+
+       offset = reset_spec->args[0];
+       bit = reset_spec->args[1];
+
+       if (bit >= BERLIN_MAX_RESETS)
+               return -EINVAL;
+
+       return (offset << 8) | bit;
+}
+
+static int berlin2_reset_probe(struct platform_device *pdev)
+{
+       struct device_node *parent_np = of_get_parent(pdev->dev.of_node);
+       struct berlin_reset_priv *priv;
+
+       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       priv->regmap = syscon_node_to_regmap(parent_np);
+       of_node_put(parent_np);
+       if (IS_ERR(priv->regmap))
+               return PTR_ERR(priv->regmap);
+
+       priv->rcdev.owner = THIS_MODULE;
+       priv->rcdev.ops = &berlin_reset_ops;
+       priv->rcdev.of_node = pdev->dev.of_node;
+       priv->rcdev.of_reset_n_cells = 2;
+       priv->rcdev.of_xlate = berlin_reset_xlate;
+
+       reset_controller_register(&priv->rcdev);
+
+       return 0;
+}
+
+static const struct of_device_id berlin_reset_dt_match[] = {
+       { .compatible = "marvell,berlin2-reset" },
+       { },
+};
+MODULE_DEVICE_TABLE(of, berlin_reset_dt_match);
+
+static struct platform_driver berlin_reset_driver = {
+       .probe  = berlin2_reset_probe,
+       .driver = {
+               .name = "berlin2-reset",
+               .of_match_table = berlin_reset_dt_match,
+       },
+};
+module_platform_driver(berlin_reset_driver);
+
+MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
+MODULE_AUTHOR("Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>");
+MODULE_DESCRIPTION("Marvell Berlin reset driver");
+MODULE_LICENSE("GPL");