[PATCH 1/2] reset: add reset-simple to unify socfpga, stm32, and sunxi

[Philipp Zabel <p.zabel@pengutronix.de>]

Reset operations for simple reset controllers with reset lines that can
be controlled by toggling bits in (mostly) contiguous register ranges
using read-modify-write cycles under a spinlock. So far this covers the
socfpga, stm32, and sunxi drivers.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
 drivers/reset/Kconfig         |  6 +++
 drivers/reset/Makefile        |  1 +
 drivers/reset/reset-simple.c  | 92 +++++++++++++++++++++++++++++++++++++++++
 drivers/reset/reset-simple.h  | 53 ++++++++++++++++++++++++
 drivers/reset/reset-socfpga.c | 96 +++++--------------------------------------
 drivers/reset/reset-stm32.c   | 73 ++++----------------------------
 drivers/reset/reset-sunxi.c   | 82 +++++-------------------------------
 7 files changed, 181 insertions(+), 222 deletions(-)
 create mode 100644 drivers/reset/reset-simple.c
 create mode 100644 drivers/reset/reset-simple.h

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index d21c07ccc94e5..d968becd0474c 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -62,21 +62,27 @@ config RESET_PISTACHIO
 	help
 	  This enables the reset driver for ImgTec Pistachio SoCs.
 
+config RESET_SIMPLE
+	bool
+
 config RESET_SOCFPGA
 	bool "SoCFPGA Reset Driver" if COMPILE_TEST
 	default ARCH_SOCFPGA
+	select RESET_SIMPLE
 	help
 	  This enables the reset controller driver for Altera SoCFPGAs.
 
 config RESET_STM32
 	bool "STM32 Reset Driver" if COMPILE_TEST
 	default ARCH_STM32
+	select RESET_SIMPLE
 	help
 	  This enables the RCC reset controller driver for STM32 MCUs.
 
 config RESET_SUNXI
 	bool "Allwinner SoCs Reset Driver" if COMPILE_TEST && !ARCH_SUNXI
 	default ARCH_SUNXI
+	select RESET_SIMPLE
 	help
 	  This enables the reset driver for Allwinner SoCs.
 
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 02a74db943397..f5cc015f20956 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
 obj-$(CONFIG_RESET_MESON) += reset-meson.o
 obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
 obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o
+obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o
 obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
 obj-$(CONFIG_RESET_STM32) += reset-stm32.o
 obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
diff --git a/drivers/reset/reset-simple.c b/drivers/reset/reset-simple.c
new file mode 100644
index 0000000000000..2160e84fe216b
--- /dev/null
+++ b/drivers/reset/reset-simple.c
@@ -0,0 +1,92 @@
+/*
+ * Simple Reset Controller ops
+ *
+ * Based on Allwinner SoCs Reset Controller driver
+ *
+ * Copyright 2013 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * 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.
+ */
+
+#include <linux/io.h>
+#include <linux/device.h>
+#include <linux/reset-controller.h>
+#include <linux/spinlock.h>
+
+#include "reset-simple.h"
+
+static inline struct reset_simple_data *
+to_reset_simple_data(struct reset_controller_dev *rcdev)
+{
+	return container_of(rcdev, struct reset_simple_data, rcdev);
+}
+
+static int reset_simple_clear(struct reset_controller_dev *rcdev,
+			      unsigned long id)
+{
+	struct reset_simple_data *data = to_reset_simple_data(rcdev);
+	int reg_width = sizeof(u32);
+	int bank = id / (reg_width * BITS_PER_BYTE);
+	int offset = id % (reg_width * BITS_PER_BYTE);
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&data->lock, flags);
+
+	reg = readl(data->membase + (bank * reg_width));
+	writel(reg & ~BIT(offset), data->membase + (bank * reg_width));
+
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return 0;
+}
+
+static int reset_simple_set(struct reset_controller_dev *rcdev,
+			    unsigned long id)
+{
+	struct reset_simple_data *data = to_reset_simple_data(rcdev);
+	int reg_width = sizeof(u32);
+	int bank = id / (reg_width * BITS_PER_BYTE);
+	int offset = id % (reg_width * BITS_PER_BYTE);
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&data->lock, flags);
+
+	reg = readl(data->membase + (bank * reg_width));
+	writel(reg | BIT(offset), data->membase + (bank * reg_width));
+
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return 0;
+}
+
+static int reset_simple_status(struct reset_controller_dev *rcdev,
+			       unsigned long id)
+{
+	struct reset_simple_data *data = to_reset_simple_data(rcdev);
+	int reg_width = sizeof(u32);
+	int bank = id / (reg_width * BITS_PER_BYTE);
+	int offset = id % (reg_width * BITS_PER_BYTE);
+	u32 reg;
+
+	reg = readl(data->membase + (bank * reg_width));
+
+	return !(reg & BIT(offset));
+}
+
+const struct reset_control_ops reset_simple_ops = {
+	.assert		= reset_simple_set,
+	.deassert	= reset_simple_clear,
+	.status		= reset_simple_status,
+};
+
+const struct reset_control_ops reset_simple_ops_inv = {
+	.assert		= reset_simple_clear,
+	.deassert	= reset_simple_set,
+};
diff --git a/drivers/reset/reset-simple.h b/drivers/reset/reset-simple.h
new file mode 100644
index 0000000000000..421a0795a2372
--- /dev/null
+++ b/drivers/reset/reset-simple.h
@@ -0,0 +1,53 @@
+/*
+ * Simple Reset Controller ops
+ *
+ * Based on Allwinner SoCs Reset Controller driver
+ *
+ * Copyright 2013 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * 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.
+ */
+
+#ifndef __RESET_SIMPLE_H__
+#define __RESET_SIMPLE_H__
+
+#include <linux/io.h>
+#include <linux/reset-controller.h>
+#include <linux/spinlock.h>
+
+struct reset_simple_data {
+	spinlock_t			lock;
+	void __iomem			*membase;
+	struct reset_controller_dev	rcdev;
+};
+
+extern const struct reset_control_ops reset_simple_ops;
+extern const struct reset_control_ops reset_simple_ops_inv;
+
+static inline int devm_reset_controller_register_simple(struct device *dev,
+							void __iomem *membase,
+							unsigned int nr_resets,
+							bool inverted)
+{
+	struct reset_simple_data *data;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	spin_lock_init(&data->lock);
+
+	data->rcdev.owner = THIS_MODULE;
+	data->rcdev.nr_resets = nr_resets;
+	data->rcdev.ops = inverted ? &reset_simple_ops_inv : &reset_simple_ops;
+	data->rcdev.of_node = dev->of_node;
+
+	return devm_reset_controller_register(dev, &data->rcdev);
+}
+
+#endif /* __RESET_SIMPLE_H__ */
diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c
index 07224c0198920..6031a3873bc8f 100644
--- a/drivers/reset/reset-socfpga.c
+++ b/drivers/reset/reset-socfpga.c
@@ -25,83 +25,16 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
-#define BANK_INCREMENT		4
-#define NR_BANKS		8
-
-struct socfpga_reset_data {
-	spinlock_t			lock;
-	void __iomem			*membase;
-	struct reset_controller_dev	rcdev;
-};
-
-static int socfpga_reset_assert(struct reset_controller_dev *rcdev,
-				unsigned long id)
-{
-	struct socfpga_reset_data *data = container_of(rcdev,
-						     struct socfpga_reset_data,
-						     rcdev);
-	int bank = id / BITS_PER_LONG;
-	int offset = id % BITS_PER_LONG;
-	unsigned long flags;
-	u32 reg;
-
-	spin_lock_irqsave(&data->lock, flags);
-
-	reg = readl(data->membase + (bank * BANK_INCREMENT));
-	writel(reg | BIT(offset), data->membase + (bank * BANK_INCREMENT));
-	spin_unlock_irqrestore(&data->lock, flags);
-
-	return 0;
-}
-
-static int socfpga_reset_deassert(struct reset_controller_dev *rcdev,
-				  unsigned long id)
-{
-	struct socfpga_reset_data *data = container_of(rcdev,
-						     struct socfpga_reset_data,
-						     rcdev);
-
-	int bank = id / BITS_PER_LONG;
-	int offset = id % BITS_PER_LONG;
-	unsigned long flags;
-	u32 reg;
-
-	spin_lock_irqsave(&data->lock, flags);
-
-	reg = readl(data->membase + (bank * BANK_INCREMENT));
-	writel(reg & ~BIT(offset), data->membase + (bank * BANK_INCREMENT));
+#include "reset-simple.h"
 
-	spin_unlock_irqrestore(&data->lock, flags);
-
-	return 0;
-}
-
-static int socfpga_reset_status(struct reset_controller_dev *rcdev,
-				unsigned long id)
-{
-	struct socfpga_reset_data *data = container_of(rcdev,
-						struct socfpga_reset_data, rcdev);
-	int bank = id / BITS_PER_LONG;
-	int offset = id % BITS_PER_LONG;
-	u32 reg;
-
-	reg = readl(data->membase + (bank * BANK_INCREMENT));
-
-	return !(reg & BIT(offset));
-}
-
-static const struct reset_control_ops socfpga_reset_ops = {
-	.assert		= socfpga_reset_assert,
-	.deassert	= socfpga_reset_deassert,
-	.status		= socfpga_reset_status,
-};
+#define NR_BANKS		8
 
 static int socfpga_reset_probe(struct platform_device *pdev)
 {
-	struct socfpga_reset_data *data;
 	struct resource *res;
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
+	void __iomem *membase;
 	u32 modrst_offset;
 
 	/*
@@ -114,29 +47,20 @@ static int socfpga_reset_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
-
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	data->membase = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(data->membase))
-		return PTR_ERR(data->membase);
+	membase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(membase))
+		return PTR_ERR(membase);
 
 	if (of_property_read_u32(np, "altr,modrst-offset", &modrst_offset)) {
 		dev_warn(dev, "missing altr,modrst-offset property, assuming 0x10!\n");
 		modrst_offset = 0x10;
 	}
-	data->membase += modrst_offset;
-
-	spin_lock_init(&data->lock);
-
-	data->rcdev.owner = THIS_MODULE;
-	data->rcdev.nr_resets = NR_BANKS * BITS_PER_LONG;
-	data->rcdev.ops = &socfpga_reset_ops;
-	data->rcdev.of_node = pdev->dev.of_node;
+	membase += modrst_offset;
 
-	return devm_reset_controller_register(dev, &data->rcdev);
+	return devm_reset_controller_register_simple(&pdev->dev, membase,
+						     NR_BANKS * BITS_PER_LONG,
+						     false);
 }
 
 static const struct of_device_id socfpga_reset_dt_ids[] = {
diff --git a/drivers/reset/reset-stm32.c b/drivers/reset/reset-stm32.c
index 3a7c8527e66af..15d89d66863d8 100644
--- a/drivers/reset/reset-stm32.c
+++ b/drivers/reset/reset-stm32.c
@@ -16,58 +16,7 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
-struct stm32_reset_data {
-	spinlock_t			lock;
-	void __iomem			*membase;
-	struct reset_controller_dev	rcdev;
-};
-
-static int stm32_reset_assert(struct reset_controller_dev *rcdev,
-			      unsigned long id)
-{
-	struct stm32_reset_data *data = container_of(rcdev,
-						     struct stm32_reset_data,
-						     rcdev);
-	int bank = id / BITS_PER_LONG;
-	int offset = id % BITS_PER_LONG;
-	unsigned long flags;
-	u32 reg;
-
-	spin_lock_irqsave(&data->lock, flags);
-
-	reg = readl(data->membase + (bank * 4));
-	writel(reg | BIT(offset), data->membase + (bank * 4));
-
-	spin_unlock_irqrestore(&data->lock, flags);
-
-	return 0;
-}
-
-static int stm32_reset_deassert(struct reset_controller_dev *rcdev,
-				unsigned long id)
-{
-	struct stm32_reset_data *data = container_of(rcdev,
-						     struct stm32_reset_data,
-						     rcdev);
-	int bank = id / BITS_PER_LONG;
-	int offset = id % BITS_PER_LONG;
-	unsigned long flags;
-	u32 reg;
-
-	spin_lock_irqsave(&data->lock, flags);
-
-	reg = readl(data->membase + (bank * 4));
-	writel(reg & ~BIT(offset), data->membase + (bank * 4));
-
-	spin_unlock_irqrestore(&data->lock, flags);
-
-	return 0;
-}
-
-static const struct reset_control_ops stm32_reset_ops = {
-	.assert		= stm32_reset_assert,
-	.deassert	= stm32_reset_deassert,
-};
+#include "reset-simple.h"
 
 static const struct of_device_id stm32_reset_dt_ids[] = {
 	 { .compatible = "st,stm32-rcc", },
@@ -76,26 +25,22 @@ static const struct of_device_id stm32_reset_dt_ids[] = {
 
 static int stm32_reset_probe(struct platform_device *pdev)
 {
-	struct stm32_reset_data *data;
+	struct reset_simple_data *data;
 	struct resource *res;
+	void __iomem *membase;
 
 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	data->membase = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(data->membase))
-		return PTR_ERR(data->membase);
-
-	spin_lock_init(&data->lock);
-
-	data->rcdev.owner = THIS_MODULE;
-	data->rcdev.nr_resets = resource_size(res) * 8;
-	data->rcdev.ops = &stm32_reset_ops;
-	data->rcdev.of_node = pdev->dev.of_node;
+	membase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(membase))
+		return PTR_ERR(membase);
 
-	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
+	return devm_reset_controller_register_simple(&pdev->dev, membase,
+						     resource_size(res) * 8,
+						     false);
 }
 
 static struct platform_driver stm32_reset_driver = {
diff --git a/drivers/reset/reset-sunxi.c b/drivers/reset/reset-sunxi.c
index cd585cd2f04dd..60745dd6f70a6 100644
--- a/drivers/reset/reset-sunxi.c
+++ b/drivers/reset/reset-sunxi.c
@@ -22,64 +22,11 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
-struct sunxi_reset_data {
-	spinlock_t			lock;
-	void __iomem			*membase;
-	struct reset_controller_dev	rcdev;
-};
-
-static int sunxi_reset_assert(struct reset_controller_dev *rcdev,
-			      unsigned long id)
-{
-	struct sunxi_reset_data *data = container_of(rcdev,
-						     struct sunxi_reset_data,
-						     rcdev);
-	int reg_width = sizeof(u32);
-	int bank = id / (reg_width * BITS_PER_BYTE);
-	int offset = id % (reg_width * BITS_PER_BYTE);
-	unsigned long flags;
-	u32 reg;
-
-	spin_lock_irqsave(&data->lock, flags);
-
-	reg = readl(data->membase + (bank * reg_width));
-	writel(reg & ~BIT(offset), data->membase + (bank * reg_width));
-
-	spin_unlock_irqrestore(&data->lock, flags);
-
-	return 0;
-}
-
-static int sunxi_reset_deassert(struct reset_controller_dev *rcdev,
-				unsigned long id)
-{
-	struct sunxi_reset_data *data = container_of(rcdev,
-						     struct sunxi_reset_data,
-						     rcdev);
-	int reg_width = sizeof(u32);
-	int bank = id / (reg_width * BITS_PER_BYTE);
-	int offset = id % (reg_width * BITS_PER_BYTE);
-	unsigned long flags;
-	u32 reg;
-
-	spin_lock_irqsave(&data->lock, flags);
-
-	reg = readl(data->membase + (bank * reg_width));
-	writel(reg | BIT(offset), data->membase + (bank * reg_width));
-
-	spin_unlock_irqrestore(&data->lock, flags);
-
-	return 0;
-}
-
-static const struct reset_control_ops sunxi_reset_ops = {
-	.assert		= sunxi_reset_assert,
-	.deassert	= sunxi_reset_deassert,
-};
+#include "reset-simple.h"
 
 static int sunxi_reset_init(struct device_node *np)
 {
-	struct sunxi_reset_data *data;
+	struct reset_simple_data *data;
 	struct resource res;
 	resource_size_t size;
 	int ret;
@@ -108,7 +55,7 @@ static int sunxi_reset_init(struct device_node *np)
 
 	data->rcdev.owner = THIS_MODULE;
 	data->rcdev.nr_resets = size * 32;
-	data->rcdev.ops = &sunxi_reset_ops;
+	data->rcdev.ops = &reset_simple_ops_inv;
 	data->rcdev.of_node = np;
 
 	return reset_controller_register(&data->rcdev);
@@ -147,26 +94,17 @@ static const struct of_device_id sunxi_reset_dt_ids[] = {
 
 static int sunxi_reset_probe(struct platform_device *pdev)
 {
-	struct sunxi_reset_data *data;
 	struct resource *res;
-
-	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
+	void __iomem *membase;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	data->membase = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(data->membase))
-		return PTR_ERR(data->membase);
-
-	spin_lock_init(&data->lock);
-
-	data->rcdev.owner = THIS_MODULE;
-	data->rcdev.nr_resets = resource_size(res) * 32;
-	data->rcdev.ops = &sunxi_reset_ops;
-	data->rcdev.of_node = pdev->dev.of_node;
+	membase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(membase))
+		return PTR_ERR(membase);
 
-	return devm_reset_controller_register(&pdev->dev, &data->rcdev);
+	return devm_reset_controller_register_simple(&pdev->dev, membase,
+						     resource_size(res) * 32,
+						     true);
 }
 
 static struct platform_driver sunxi_reset_driver = {
-- 
2.11.0