clk: rockchip: add reset controller
From: Heiko Stuebner <heiko@...> Date: Sun, 13 Apr 2014 21:47:19 +0200
Commit-Message
All Rockchip SoCs at least down to the ARM9-based RK28xx include the reset- controller for SoC peripherals in their clock controller. While the older SoCs (ARM9 and Cortex-A8) use a regular scheme to change register values, the Cortex-A9 SoCs use a hiword-mask making locking unecessary. To be compatible with both schemes the reset controller takes a flag to decide which scheme to use. Signed-off-by: Heiko Stuebner <heiko@...>
Patch-Comment
drivers/clk/rockchip/Makefile | 1 + drivers/clk/rockchip/clk.h | 14 +++++ drivers/clk/rockchip/softrst.c | 115 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 130 insertions(+) create mode 100644 drivers/clk/rockchip/softrst.c
Statistics
- 130 lines added
- 0 lines removed
Changes
------------------------ drivers/clk/rockchip/Makefile -------------------------
index 7748062..7e4a296 100644
@@ -6,3 +6,4 @@ obj-y += clk-rockchip.o
obj-y += clk.o
obj-y += clk-pll.o
obj-y += clk-cpu.o
+obj-$(CONFIG_RESET_CONTROLLER) += softrst.o
-------------------------- drivers/clk/rockchip/clk.h --------------------------
index 7d1c76c..b52e4c2 100644
@@ -234,4 +234,18 @@ void rockchip_clk_register_armclk(unsigned int lookup_id,
unsigned int num_parents, void __iomem *reg_base,
struct device_node *np);
+#define ROCKCHIP_SOFTRST_HIWORD_MASK BIT(0)
+
+#ifdef CONFIG_RESET_CONTROLLER
+void rockchip_register_softrst(struct device_node *np,
+ unsigned int num_regs,
+ void __iomem *base, u8 flags);
+#else
+static inline void rockchip_register_softrst(struct device_node *np,
+ unsigned int num_regs,
+ void __iomem *base, u8 flags)
+{
+}
+#endif
+
#endif
------------------------ drivers/clk/rockchip/softrst.c ------------------------
new file mode 100644
index 0000000..e981f6c
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2014 MundoReader S.L.
+ * Author: Heiko Stuebner <heiko@sntech.de>
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/reset-controller.h>
+#include <linux/spinlock.h>
+#include "clk.h"
+
+struct rockchip_softrst {
+ struct reset_controller_dev rcdev;
+ void __iomem *reg_base;
+ int num_regs;
+ int num_per_reg;
+ u8 flags;
+ spinlock_t lock;
+};
+
+static int rockchip_softrst_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct rockchip_softrst *softrst = container_of(rcdev,
+ struct rockchip_softrst,
+ rcdev);
+ int bank = id / softrst->num_per_reg;
+ int offset = id % softrst->num_per_reg;
+
+ if (softrst->flags & ROCKCHIP_SOFTRST_HIWORD_MASK) {
+ writel(BIT(offset) | (BIT(offset) << 16),
+ softrst->reg_base + (bank * 4));
+ } else {
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(&softrst->lock, flags);
+
+ reg = readl(softrst->reg_base + (bank * 4));
+ writel(reg | BIT(offset), softrst->reg_base + (bank * 4));
+
+ spin_unlock_irqrestore(&softrst->lock, flags);
+ }
+
+ return 0;
+}
+
+static int rockchip_softrst_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ struct rockchip_softrst *softrst = container_of(rcdev,
+ struct rockchip_softrst,
+ rcdev);
+ int bank = id / BITS_PER_LONG;
+ int offset = id % BITS_PER_LONG;
+
+ if (softrst->flags & ROCKCHIP_SOFTRST_HIWORD_MASK) {
+ writel((BIT(offset) << 16), softrst->reg_base + (bank * 4));
+ } else {
+ unsigned long flags;
+ u32 reg;
+
+ spin_lock_irqsave(&softrst->lock, flags);
+
+ reg = readl(softrst->reg_base + (bank * 4));
+ writel(reg & ~BIT(offset), softrst->reg_base + (bank * 4));
+
+ spin_unlock_irqrestore(&softrst->lock, flags);
+ }
+
+ return 0;
+}
+
+static struct reset_control_ops rockchip_softrst_ops = {
+ .assert = rockchip_softrst_assert,
+ .deassert = rockchip_softrst_deassert,
+};
+
+void __init rockchip_register_softrst(struct device_node *np,
+ unsigned int num_regs,
+ void __iomem *base, u8 flags)
+{
+ struct rockchip_softrst *softrst;
+ int ret;
+
+ softrst = kzalloc(sizeof(*softrst), GFP_KERNEL);
+ if (!softrst)
+ return;
+
+ softrst->reg_base = base;
+ softrst->num_regs = num_regs;
+ softrst->num_per_reg = (flags & ROCKCHIP_SOFTRST_HIWORD_MASK) ? 16
+ : 32;
+
+ softrst->rcdev.owner = THIS_MODULE;
+ softrst->rcdev.nr_resets = num_regs * softrst->num_per_reg;
+ softrst->rcdev.ops = &rockchip_softrst_ops;
+ softrst->rcdev.of_node = np;
+ ret = reset_controller_register(&softrst->rcdev);
+ if (ret) {
+ pr_err("%s: could not register reset controller, %d\n",
+ __func__, ret);
+ kfree(softrst);
+ }
+};