[PATCH 3/4] clk: ralink: make system controller node a reset provider

[Sergio Paracuellos <sergio.paracuellos@gmail.com>]

MT7621 system controller node is already providing the clocks for the whole
system but must also serve as a reset provider. Hence, add reset controller
related code to the clock driver itself.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
---
 drivers/clk/ralink/clk-mt7621.c | 79 +++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

diff --git a/drivers/clk/ralink/clk-mt7621.c b/drivers/clk/ralink/clk-mt7621.c
index a2c045390f00..67ccc9582c46 100644
--- a/drivers/clk/ralink/clk-mt7621.c
+++ b/drivers/clk/ralink/clk-mt7621.c
@@ -11,14 +11,17 @@
 #include <linux/mfd/syscon.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
+#include <linux/reset-controller.h>
 #include <linux/slab.h>
 #include <dt-bindings/clock/mt7621-clk.h>
+#include <dt-bindings/reset/mt7621-reset.h>
 
 /* Configuration registers */
 #define SYSC_REG_SYSTEM_CONFIG0         0x10
 #define SYSC_REG_SYSTEM_CONFIG1         0x14
 #define SYSC_REG_CLKCFG0		0x2c
 #define SYSC_REG_CLKCFG1		0x30
+#define SYSC_REG_RESET_CTRL		0x34
 #define SYSC_REG_CUR_CLK_STS		0x44
 #define MEMC_REG_CPU_PLL		0x648
 
@@ -398,6 +401,76 @@ static void __init mt7621_clk_init(struct device_node *node)
 }
 CLK_OF_DECLARE_DRIVER(mt7621_clk, "mediatek,mt7621-sysc", mt7621_clk_init);
 
+struct mt7621_rst {
+	struct reset_controller_dev rcdev;
+	struct regmap *sysc;
+};
+
+static inline struct mt7621_rst *to_mt7621_rst(struct reset_controller_dev *dev)
+{
+	return container_of(dev, struct mt7621_rst, rcdev);
+}
+
+static int mt7621_assert_device(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	struct mt7621_rst *data = to_mt7621_rst(rcdev);
+	struct regmap *sysc = data->sysc;
+
+	if (id == MT7621_RST_SYS)
+		return -1;
+
+	return regmap_update_bits(sysc, SYSC_REG_RESET_CTRL, BIT(id), BIT(id));
+}
+
+static int mt7621_deassert_device(struct reset_controller_dev *rcdev,
+				  unsigned long id)
+{
+	struct mt7621_rst *data = to_mt7621_rst(rcdev);
+	struct regmap *sysc = data->sysc;
+
+	if (id == MT7621_RST_SYS)
+		return -1;
+
+	return regmap_update_bits(sysc, SYSC_REG_RESET_CTRL, BIT(id), 0);
+}
+
+static int mt7621_reset_device(struct reset_controller_dev *rcdev,
+			       unsigned long id)
+{
+	int ret;
+
+	ret = mt7621_assert_device(rcdev, id);
+	if (ret < 0)
+		return ret;
+
+	return mt7621_deassert_device(rcdev, id);
+}
+
+static const struct reset_control_ops reset_ops = {
+	.reset = mt7621_reset_device,
+	.assert = mt7621_assert_device,
+	.deassert = mt7621_deassert_device
+};
+
+static int mt7621_reset_init(struct device *dev, struct regmap *sysc)
+{
+	struct mt7621_rst *rst_data;
+
+	rst_data = kzalloc(sizeof(*rst_data), GFP_KERNEL);
+	if (!rst_data)
+		return -ENOMEM;
+
+	rst_data->sysc = sysc;
+	rst_data->rcdev.ops = &reset_ops;
+	rst_data->rcdev.owner = THIS_MODULE;
+	rst_data->rcdev.nr_resets = 32;
+	rst_data->rcdev.of_reset_n_cells = 1;
+	rst_data->rcdev.of_node = dev_of_node(dev);
+
+	return devm_reset_controller_register(dev, &rst_data->rcdev);
+}
+
 static int mt7621_clk_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
@@ -424,6 +497,12 @@ static int mt7621_clk_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	ret = mt7621_reset_init(dev, priv->sysc);
+	if (ret) {
+		pr_err("Could not init reset controller\n");
+		return ret;
+	}
+
 	count = ARRAY_SIZE(mt7621_clks_base) +
 		ARRAY_SIZE(mt7621_fixed_clks) + ARRAY_SIZE(mt7621_gates);
 	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, count),
-- 
2.33.0