[PATCH 3/6] clk: mediatek: Add reset controller support

From: Sascha Hauer
Date: Thu Mar 19 2015 - 04:43:33 EST


The pericfg and infracfg units also provide reset lines to several
other SoC internal units. Add support for the reset controller.

Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
drivers/clk/mediatek/Makefile | 1 +
drivers/clk/mediatek/clk-mtk.h | 10 +++++
drivers/clk/mediatek/reset.c | 99 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 110 insertions(+)
create mode 100644 drivers/clk/mediatek/reset.c

diff --git a/drivers/clk/mediatek/Makefile b/drivers/clk/mediatek/Makefile
index c384e97..0b6f1c3 100644
--- a/drivers/clk/mediatek/Makefile
+++ b/drivers/clk/mediatek/Makefile
@@ -1 +1,2 @@
obj-y += clk-mtk.o clk-pll.o clk-gate.o
+obj-$(CONFIG_RESET_CONTROLLER) += reset.o
diff --git a/drivers/clk/mediatek/clk-mtk.h b/drivers/clk/mediatek/clk-mtk.h
index 5aaba81..5a6b5dd 100644
--- a/drivers/clk/mediatek/clk-mtk.h
+++ b/drivers/clk/mediatek/clk-mtk.h
@@ -152,4 +152,14 @@ void __init mtk_clk_register_plls(struct device_node *node,
const struct mtk_pll_data *plls, int num_plls,
struct clk_onecell_data *clk_data);

+#ifdef CONFIG_RESET_CONTROLLER
+void mtk_register_reset_controller(struct device_node *np,
+ unsigned int num_regs, int regofs);
+#else
+static inline void mtk_register_reset_controller(struct device_node *np,
+ unsigned int num_regs, int regofs)
+{
+}
+#endif
+
#endif /* __DRV_CLK_MTK_H */
diff --git a/drivers/clk/mediatek/reset.c b/drivers/clk/mediatek/reset.c
new file mode 100644
index 0000000..3a85a53
--- /dev/null
+++ b/drivers/clk/mediatek/reset.c
@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2014 MediaTek Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+
+#include "clk-mtk.h"
+
+struct mtk_reset {
+ struct regmap *regmap;
+ int regofs;
+ struct reset_controller_dev rcdev;
+};
+
+static int mtk_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
+
+ return regmap_update_bits(data->regmap, data->regofs + ((id / 32) << 2),
+ BIT(id % 32), ~0);
+}
+
+static int mtk_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
+
+ return regmap_update_bits(data->regmap, data->regofs + ((id / 32) << 2),
+ BIT(id % 32), 0);
+}
+
+static int mtk_reset(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ int ret;
+
+ ret = mtk_reset_assert(rcdev, id);
+ if (ret)
+ return ret;
+
+ return mtk_reset_deassert(rcdev, id);
+}
+
+static struct reset_control_ops mtk_reset_ops = {
+ .assert = mtk_reset_assert,
+ .deassert = mtk_reset_deassert,
+ .reset = mtk_reset,
+};
+
+void mtk_register_reset_controller(struct device_node *np,
+ unsigned int num_regs, int regofs)
+{
+ struct mtk_reset *data;
+ int ret;
+ struct regmap *regmap;
+
+ regmap = syscon_node_to_regmap(np);
+ if (IS_ERR(regmap)) {
+ pr_err("Cannot find regmap for %s: %ld\n", np->full_name,
+ PTR_ERR(regmap));
+ return;
+ }
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return;
+
+ data->regmap = regmap;
+ data->regofs = regofs;
+ data->rcdev.owner = THIS_MODULE;
+ data->rcdev.nr_resets = num_regs * 32;
+ data->rcdev.ops = &mtk_reset_ops;
+ data->rcdev.of_node = np;
+
+ ret = reset_controller_register(&data->rcdev);
+ if (ret) {
+ pr_err("could not register reset controller: %d\n", ret);
+ kfree(data);
+ return;
+ }
+}
--
2.1.4

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