[PATCH 04/11] reset: berlin: convert to a platform driver

[Antoine Tenart <antoine.tenart@free-electrons.com>]

The Berlin reset controller was introduced without being a platform
driver because of a needed DT rework: the node describing the reset
controller also describes the pinctrl and clk controllers...

The DT issue being solved thanks to the addition of the Berlin
controller mfd driver, it is now possible to convert the Berlin reset
driver to a plaftorm driver.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
 drivers/reset/reset-berlin.c | 69 +++++++++++++++++---------------------------
 1 file changed, 26 insertions(+), 43 deletions(-)

diff --git a/drivers/reset/reset-berlin.c b/drivers/reset/reset-berlin.c
index f8b48a13cf0b..fd44f872a212 100644
--- a/drivers/reset/reset-berlin.c
+++ b/drivers/reset/reset-berlin.c
@@ -12,10 +12,12 @@
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/module.h>
+#include <linux/mfd/syscon.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/reset-controller.h>
+#include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 
@@ -25,8 +27,7 @@
 	container_of((p), struct berlin_reset_priv, rcdev)
 
 struct berlin_reset_priv {
-	void __iomem			*base;
-	unsigned int			size;
+	struct regmap			*regmap;
 	struct reset_controller_dev	rcdev;
 };
 
@@ -37,7 +38,7 @@ static int berlin_reset_reset(struct reset_controller_dev *rcdev,
 	int offset = id >> 8;
 	int mask = BIT(id & 0x1f);
 
-	writel(mask, priv->base + offset);
+	regmap_write(priv->regmap, offset, mask);
 
 	/* let the reset be effective */
 	udelay(10);
@@ -52,7 +53,6 @@ static struct reset_control_ops berlin_reset_ops = {
 static int berlin_reset_xlate(struct reset_controller_dev *rcdev,
 			      const struct of_phandle_args *reset_spec)
 {
-	struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev);
 	unsigned offset, bit;
 
 	if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
@@ -61,71 +61,54 @@ static int berlin_reset_xlate(struct reset_controller_dev *rcdev,
 	offset = reset_spec->args[0];
 	bit = reset_spec->args[1];
 
-	if (offset >= priv->size)
-		return -EINVAL;
-
 	if (bit >= BERLIN_MAX_RESETS)
 		return -EINVAL;
 
 	return (offset << 8) | bit;
 }
 
-static int __berlin_reset_init(struct device_node *np)
+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;
-	struct resource res;
-	resource_size_t size;
-	int ret;
 
-	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
 
-	ret = of_address_to_resource(np, 0, &res);
-	if (ret)
-		goto err;
-
-	size = resource_size(&res);
-	priv->base = ioremap(res.start, size);
-	if (!priv->base) {
-		ret = -ENOMEM;
-		goto err;
-	}
-	priv->size = size;
+	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 = np;
+	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;
-
-err:
-	kfree(priv);
-	return ret;
 }
 
 static const struct of_device_id berlin_reset_of_match[] __initconst = {
-	{ .compatible = "marvell,berlin2-chip-ctrl" },
-	{ .compatible = "marvell,berlin2cd-chip-ctrl" },
-	{ .compatible = "marvell,berlin2q-chip-ctrl" },
+	{ .compatible = "marvell,berlin2-reset" },
 	{ },
 };
+MODULE_DEVICE_TABLE(of, berlin_reset_of_match);
 
-static int __init berlin_reset_init(void)
-{
-	struct device_node *np;
-	int ret;
+static struct platform_driver berlin_reset_driver = {
+	.probe	= berlin2_reset_probe,
+	.driver	= {
+		.name = "berlin2-reset",
+		.of_match_table = berlin_reset_of_match,
+	},
 
-	for_each_matching_node(np, berlin_reset_of_match) {
-		ret = __berlin_reset_init(np);
-		if (ret)
-			return ret;
-	}
+};
+module_platform_driver(berlin_reset_driver);
 
-	return 0;
-}
-arch_initcall(berlin_reset_init);
+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");
-- 
2.3.0