Merge tag 'reset-for-4.6' of git://git.pengutronix.de/git/pza/linux into next/drivers

Reset controller changes for v4.6

- add support for the imgtec Pistachio SoC reset controller
- make struct reset_control_ops const
- move DT cell size check into the core to avoid code duplication
  in the drivers

* tag 'reset-for-4.6' of git://git.pengutronix.de/git/pza/linux:
  reset: sti: Make reset_control_ops const
  reset: zynq: Make reset_control_ops const
  reset: socfpga: Make reset_control_ops const
  reset: hi6220: Make reset_control_ops const
  reset: ath79: Make reset_control_ops const
  reset: lpc18xx: Make reset_control_ops const
  reset: sunxi: Make reset_control_ops const
  reset: img: Make reset_control_ops const
  reset: berlin: Make reset_control_ops const
  reset: berlin: drop DT cell size check
  reset: img: Add Pistachio reset controller driver
  reset: img: Add pistachio reset controller binding document
  reset: hisilicon: check return value of reset_controller_register()
  reset: Move DT cell size check to the core
  reset: Make reset_control_ops const
  reset: remove unnecessary local variable initialization from of_reset_control_get_by_index

Signed-off-by: Olof Johansson <olof@lixom.net>

Documentation/devicetree/bindings/reset/img,pistachio-reset.txt

@@ -0,0 +1,55 @@
+Pistachio Reset Controller
+=============================================================================
+
+This binding describes a reset controller device that is used to enable and
+disable individual IP blocks within the Pistachio SoC using "soft reset"
+control bits found in the Pistachio SoC top level registers.
+
+The actual action taken when soft reset is asserted is hardware dependent.
+However, when asserted it may not be possible to access the hardware's
+registers, and following an assert/deassert sequence the hardware's previous
+state may no longer be valid.
+
+Please refer to Documentation/devicetree/bindings/reset/reset.txt
+for common reset controller binding usage.
+
+Required properties:
+
+- compatible: Contains "img,pistachio-reset"
+
+- #reset-cells: Contains 1
+
+Example:
+
+	cr_periph: clk@18148000 {
+		compatible = "img,pistachio-cr-periph", "syscon", "simple-mfd";
+		reg = <0x18148000 0x1000>;
+		clocks = <&clk_periph PERIPH_CLK_SYS>;
+		clock-names = "sys";
+		#clock-cells = <1>;
+
+		pistachio_reset: reset-controller {
+			compatible = "img,pistachio-reset";
+			#reset-cells = <1>;
+		};
+	};
+
+Specifying reset control of devices
+=======================================
+
+Device nodes should specify the reset channel required in their "resets"
+property, containing a phandle to the pistachio reset device node and an
+index specifying which reset to use, as described in
+Documentation/devicetree/bindings/reset/reset.txt.
+
+Example:
+
+	spdif_out: spdif-out@18100d00 {
+		...
+		resets = <&pistachio_reset PISTACHIO_RESET_SPDIF_OUT>;
+		reset-names = "rst";
+		...
+	};
+
+Macro definitions for the supported resets can be found in:
+include/dt-bindings/reset/pistachio-resets.h

drivers/reset/Makefile

@@ -2,6 +2,7 @@ obj-y += core.o
 obj-$(CONFIG_ARCH_LPC18XX) += reset-lpc18xx.o
 obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
 obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o
+obj-$(CONFIG_MACH_PISTACHIO) += reset-pistachio.o
 obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
 obj-$(CONFIG_ARCH_STI) += sti/
 obj-$(CONFIG_ARCH_HISI) += hisilicon/

drivers/reset/core.c

@@ -45,9 +45,6 @@ struct reset_control {
 static int of_reset_simple_xlate(struct reset_controller_dev *rcdev,
 			  const struct of_phandle_args *reset_spec)
 {
-	if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
-		return -EINVAL;
-
 	if (reset_spec->args[0] >= rcdev->nr_resets)
 		return -EINVAL;
 
@@ -152,7 +149,7 @@ EXPORT_SYMBOL_GPL(reset_control_status);
 struct reset_control *of_reset_control_get_by_index(struct device_node *node,
 					   int index)
 {
-	struct reset_control *rstc = ERR_PTR(-EPROBE_DEFER);
+	struct reset_control *rstc;
 	struct reset_controller_dev *r, *rcdev;
 	struct of_phandle_args args;
 	int rstc_id;
@@ -178,6 +175,11 @@ struct reset_control *of_reset_control_get_by_index(struct device_node *node,
 		return ERR_PTR(-EPROBE_DEFER);
 	}
 
+	if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {
+		mutex_unlock(&reset_controller_list_mutex);
+		return ERR_PTR(-EINVAL);
+	}
+
 	rstc_id = rcdev->of_xlate(rcdev, &args);
 	if (rstc_id < 0) {
 		mutex_unlock(&reset_controller_list_mutex);

drivers/reset/hisilicon/hi6220_reset.c

@@ -57,7 +57,7 @@ static int hi6220_reset_deassert(struct reset_controller_dev *rc_dev,
 	return 0;
 }
 
-static struct reset_control_ops hi6220_reset_ops = {
+static const struct reset_control_ops hi6220_reset_ops = {
 	.assert = hi6220_reset_assert,
 	.deassert = hi6220_reset_deassert,
 };
@@ -83,9 +83,7 @@ static int hi6220_reset_probe(struct platform_device *pdev)
 	data->rc_dev.ops = &hi6220_reset_ops;
 	data->rc_dev.of_node = pdev->dev.of_node;
 
-	reset_controller_register(&data->rc_dev);
-
-	return 0;
+	return reset_controller_register(&data->rc_dev);
 }
 
 static const struct of_device_id hi6220_reset_match[] = {

drivers/reset/reset-ath79.c

@@ -70,7 +70,7 @@ static int ath79_reset_status(struct reset_controller_dev *rcdev,
 	return !!(val & BIT(id));
 }
 
-static struct reset_control_ops ath79_reset_ops = {
+static const struct reset_control_ops ath79_reset_ops = {
 	.assert = ath79_reset_assert,
 	.deassert = ath79_reset_deassert,
 	.status = ath79_reset_status,

drivers/reset/reset-berlin.c

@@ -46,7 +46,7 @@ static int berlin_reset_reset(struct reset_controller_dev *rcdev,
 	return 0;
 }
 
-static struct reset_control_ops berlin_reset_ops = {
+static const struct reset_control_ops berlin_reset_ops = {
 	.reset	= berlin_reset_reset,
 };
 
@@ -55,9 +55,6 @@ static int berlin_reset_xlate(struct reset_controller_dev *rcdev,
 {
 	unsigned offset, bit;
 
-	if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
-		return -EINVAL;
-
 	offset = reset_spec->args[0];
 	bit = reset_spec->args[1];
 

drivers/reset/reset-lpc18xx.c

@@ -136,7 +136,7 @@ static int lpc18xx_rgu_status(struct reset_controller_dev *rcdev,
 	return !(readl(rc->base + offset) & bit);
 }
 
-static struct reset_control_ops lpc18xx_rgu_ops = {
+static const struct reset_control_ops lpc18xx_rgu_ops = {
 	.reset		= lpc18xx_rgu_reset,
 	.assert		= lpc18xx_rgu_assert,
 	.deassert	= lpc18xx_rgu_deassert,

drivers/reset/reset-pistachio.c

@@ -0,0 +1,154 @@
+/*
+ * Pistachio SoC Reset Controller driver
+ *
+ * Copyright (C) 2015 Imagination Technologies Ltd.
+ *
+ * Author: Damien Horsley <Damien.Horsley@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#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 <linux/mfd/syscon.h>
+
+#include <dt-bindings/reset/pistachio-resets.h>
+
+#define	PISTACHIO_SOFT_RESET		0
+
+struct pistachio_reset_data {
+	struct reset_controller_dev	rcdev;
+	struct regmap			*periph_regs;
+};
+
+static inline int pistachio_reset_shift(unsigned long id)
+{
+	switch (id) {
+	case PISTACHIO_RESET_I2C0:
+	case PISTACHIO_RESET_I2C1:
+	case PISTACHIO_RESET_I2C2:
+	case PISTACHIO_RESET_I2C3:
+	case PISTACHIO_RESET_I2S_IN:
+	case PISTACHIO_RESET_PRL_OUT:
+	case PISTACHIO_RESET_SPDIF_OUT:
+	case PISTACHIO_RESET_SPI:
+	case PISTACHIO_RESET_PWM_PDM:
+	case PISTACHIO_RESET_UART0:
+	case PISTACHIO_RESET_UART1:
+	case PISTACHIO_RESET_QSPI:
+	case PISTACHIO_RESET_MDC:
+	case PISTACHIO_RESET_SDHOST:
+	case PISTACHIO_RESET_ETHERNET:
+	case PISTACHIO_RESET_IR:
+	case PISTACHIO_RESET_HASH:
+	case PISTACHIO_RESET_TIMER:
+		return id;
+	case PISTACHIO_RESET_I2S_OUT:
+	case PISTACHIO_RESET_SPDIF_IN:
+	case PISTACHIO_RESET_EVT:
+		return id + 6;
+	case PISTACHIO_RESET_USB_H:
+	case PISTACHIO_RESET_USB_PR:
+	case PISTACHIO_RESET_USB_PHY_PR:
+	case PISTACHIO_RESET_USB_PHY_PON:
+		return id + 7;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int pistachio_reset_assert(struct reset_controller_dev *rcdev,
+				  unsigned long id)
+{
+	struct pistachio_reset_data *rd;
+	u32 mask;
+	int shift;
+
+	rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
+	shift = pistachio_reset_shift(id);
+	if (shift < 0)
+		return shift;
+	mask = BIT(shift);
+
+	return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
+				  mask, mask);
+}
+
+static int pistachio_reset_deassert(struct reset_controller_dev *rcdev,
+				    unsigned long id)
+{
+	struct pistachio_reset_data *rd;
+	u32 mask;
+	int shift;
+
+	rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
+	shift = pistachio_reset_shift(id);
+	if (shift < 0)
+		return shift;
+	mask = BIT(shift);
+
+	return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
+				  mask, 0);
+}
+
+static const struct reset_control_ops pistachio_reset_ops = {
+	.assert		= pistachio_reset_assert,
+	.deassert	= pistachio_reset_deassert,
+};
+
+static int pistachio_reset_probe(struct platform_device *pdev)
+{
+	struct pistachio_reset_data *rd;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = pdev->dev.of_node;
+
+	rd = devm_kzalloc(dev, sizeof(*rd), GFP_KERNEL);
+	if (!rd)
+		return -ENOMEM;
+
+	rd->periph_regs = syscon_node_to_regmap(np->parent);
+	if (IS_ERR(rd->periph_regs))
+		return PTR_ERR(rd->periph_regs);
+
+	rd->rcdev.owner = THIS_MODULE;
+	rd->rcdev.nr_resets = PISTACHIO_RESET_MAX + 1;
+	rd->rcdev.ops = &pistachio_reset_ops;
+	rd->rcdev.of_node = np;
+
+	return reset_controller_register(&rd->rcdev);
+}
+
+static int pistachio_reset_remove(struct platform_device *pdev)
+{
+	struct pistachio_reset_data *data = platform_get_drvdata(pdev);
+
+	reset_controller_unregister(&data->rcdev);
+
+	return 0;
+}
+
+static const struct of_device_id pistachio_reset_dt_ids[] = {
+	 { .compatible = "img,pistachio-reset", },
+	 { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, pistachio_reset_dt_ids);
+
+static struct platform_driver pistachio_reset_driver = {
+	.probe	= pistachio_reset_probe,
+	.remove	= pistachio_reset_remove,
+	.driver = {
+		.name		= "pistachio-reset",
+		.of_match_table	= pistachio_reset_dt_ids,
+	},
+};
+module_platform_driver(pistachio_reset_driver);
+
+MODULE_AUTHOR("Damien Horsley <Damien.Horsley@imgtec.com>");
+MODULE_DESCRIPTION("Pistacho Reset Controller Driver");
+MODULE_LICENSE("GPL v2");

drivers/reset/reset-socfpga.c

@@ -90,7 +90,7 @@ static int socfpga_reset_status(struct reset_controller_dev *rcdev,
 	return !(reg & BIT(offset));
 }
 
-static struct reset_control_ops socfpga_reset_ops = {
+static const struct reset_control_ops socfpga_reset_ops = {
 	.assert		= socfpga_reset_assert,
 	.deassert	= socfpga_reset_deassert,
 	.status		= socfpga_reset_status,

drivers/reset/reset-sunxi.c

@@ -70,7 +70,7 @@ static int sunxi_reset_deassert(struct reset_controller_dev *rcdev,
 	return 0;
 }
 
-static struct reset_control_ops sunxi_reset_ops = {
+static const struct reset_control_ops sunxi_reset_ops = {
 	.assert		= sunxi_reset_assert,
 	.deassert	= sunxi_reset_deassert,
 };

drivers/reset/reset-zynq.c

@@ -86,7 +86,7 @@ static int zynq_reset_status(struct reset_controller_dev *rcdev,
 	return !!(reg & BIT(offset));
 }
 
-static struct reset_control_ops zynq_reset_ops = {
+static const struct reset_control_ops zynq_reset_ops = {
 	.assert		= zynq_reset_assert,
 	.deassert	= zynq_reset_deassert,
 	.status		= zynq_reset_status,

drivers/reset/sti/reset-syscfg.c

@@ -134,7 +134,7 @@ static int syscfg_reset_status(struct reset_controller_dev *rcdev,
 	return rst->active_low ? !ret_val : !!ret_val;
 }
 
-static struct reset_control_ops syscfg_reset_ops = {
+static const struct reset_control_ops syscfg_reset_ops = {
 	.reset    = syscfg_reset_dev,
 	.assert   = syscfg_reset_assert,
 	.deassert = syscfg_reset_deassert,

include/dt-bindings/reset/pistachio-resets.h

@@ -0,0 +1,36 @@
+/*
+ * This header provides constants for the reset controller
+ * present in the Pistachio SoC
+ */
+
+#ifndef _PISTACHIO_RESETS_H
+#define _PISTACHIO_RESETS_H
+
+#define PISTACHIO_RESET_I2C0		0
+#define PISTACHIO_RESET_I2C1		1
+#define PISTACHIO_RESET_I2C2		2
+#define PISTACHIO_RESET_I2C3		3
+#define PISTACHIO_RESET_I2S_IN		4
+#define PISTACHIO_RESET_PRL_OUT		5
+#define PISTACHIO_RESET_SPDIF_OUT	6
+#define PISTACHIO_RESET_SPI		7
+#define PISTACHIO_RESET_PWM_PDM		8
+#define PISTACHIO_RESET_UART0		9
+#define PISTACHIO_RESET_UART1		10
+#define PISTACHIO_RESET_QSPI		11
+#define PISTACHIO_RESET_MDC		12
+#define PISTACHIO_RESET_SDHOST		13
+#define PISTACHIO_RESET_ETHERNET	14
+#define PISTACHIO_RESET_IR		15
+#define PISTACHIO_RESET_HASH		16
+#define PISTACHIO_RESET_TIMER		17
+#define PISTACHIO_RESET_I2S_OUT		18
+#define PISTACHIO_RESET_SPDIF_IN	19
+#define PISTACHIO_RESET_EVT		20
+#define PISTACHIO_RESET_USB_H		21
+#define PISTACHIO_RESET_USB_PR		22
+#define PISTACHIO_RESET_USB_PHY_PR	23
+#define PISTACHIO_RESET_USB_PHY_PON	24
+#define PISTACHIO_RESET_MAX		24
+
+#endif

include/linux/reset-controller.h

@@ -38,7 +38,7 @@ struct of_phandle_args;
  * @nr_resets: number of reset controls in this reset controller device
  */
 struct reset_controller_dev {
-	struct reset_control_ops *ops;
+	const struct reset_control_ops *ops;
 	struct module *owner;
 	struct list_head list;
 	struct device_node *of_node;