Merge tag 'sti-reset-for-v3.15' of git://git.stlinux.com/devel/kernel/linux-sti into next/drivers

Merge "STi Reset controller support" from Srinivas Kandagatla:

* tag 'sti-reset-for-v3.15' of git://git.stlinux.com/devel/kernel/linux-sti:
  ARM: STi: Add reset controller support to mach-sti Kconfig
  drivers: reset: stih416: add softreset controller
  drivers: reset: stih415: add softreset controller
  drivers: reset: Reset controller driver for STiH416
  drivers: reset: Reset controller driver for STiH415
  drivers: reset: STi SoC system configuration reset controller support

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/mach-sti/Kconfig

@@ -7,6 +7,7 @@ menuconfig ARCH_STI
 	select PINCTRL
 	select PINCTRL_ST
 	select MFD_SYSCON
+	select ARCH_HAS_RESET_CONTROLLER
 	select MIGHT_HAVE_CACHE_L2X0
 	select HAVE_SMP
 	select HAVE_ARM_SCU if SMP
@@ -28,6 +29,7 @@ if ARCH_STI
 config SOC_STIH415
 	bool "STiH415 STMicroelectronics Consumer Electronics family"
 	default y
+	select STIH415_RESET
 	help
 	  This enables support for STMicroelectronics Digital Consumer
 	  Electronics family StiH415 parts, primarily targeted at set-top-box
@@ -37,6 +39,7 @@ config SOC_STIH415
 config SOC_STIH416
 	bool "STiH416 STMicroelectronics Consumer Electronics family"
 	default y
+	select STIH416_RESET
 	help
 	  This enables support for STMicroelectronics Digital Consumer
 	  Electronics family StiH416 parts, primarily targeted at set-top-box

drivers/reset/Kconfig

@@ -11,3 +11,5 @@ menuconfig RESET_CONTROLLER
 	  via GPIOs or SoC-internal reset controller modules.
 
 	  If unsure, say no.
+
+source "drivers/reset/sti/Kconfig"

drivers/reset/Makefile

@@ -1,2 +1,3 @@
 obj-$(CONFIG_RESET_CONTROLLER) += core.o
 obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
+obj-$(CONFIG_ARCH_STI) += sti/

drivers/reset/sti/Kconfig

@@ -0,0 +1,15 @@
+if ARCH_STI
+
+config STI_RESET_SYSCFG
+	bool
+	select RESET_CONTROLLER
+
+config STIH415_RESET
+	bool
+	select STI_RESET_SYSCFG
+
+config STIH416_RESET
+	bool
+	select STI_RESET_SYSCFG
+
+endif

drivers/reset/sti/Makefile

@@ -0,0 +1,4 @@
+obj-$(CONFIG_STI_RESET_SYSCFG) += reset-syscfg.o
+
+obj-$(CONFIG_STIH415_RESET) += reset-stih415.o
+obj-$(CONFIG_STIH416_RESET) += reset-stih416.o

drivers/reset/sti/reset-stih415.c

@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2013 STMicroelectronics (R&D) Limited
+ * Author: Stephen Gallimore <stephen.gallimore@st.com>
+ * Author: Srinivas Kandagatla <srinivas.kandagatla@st.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/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include <dt-bindings/reset-controller/stih415-resets.h>
+
+#include "reset-syscfg.h"
+
+/*
+ * STiH415 Peripheral powerdown definitions.
+ */
+static const char stih415_front[] = "st,stih415-front-syscfg";
+static const char stih415_rear[] = "st,stih415-rear-syscfg";
+static const char stih415_sbc[] = "st,stih415-sbc-syscfg";
+static const char stih415_lpm[] = "st,stih415-lpm-syscfg";
+
+#define STIH415_PDN_FRONT(_bit) \
+	_SYSCFG_RST_CH(stih415_front, SYSCFG_114, _bit, SYSSTAT_187, _bit)
+
+#define STIH415_PDN_REAR(_cntl, _stat) \
+	_SYSCFG_RST_CH(stih415_rear, SYSCFG_336, _cntl, SYSSTAT_384, _stat)
+
+#define STIH415_SRST_REAR(_reg, _bit) \
+	_SYSCFG_RST_CH_NO_ACK(stih415_rear, _reg, _bit)
+
+#define STIH415_SRST_SBC(_reg, _bit) \
+	_SYSCFG_RST_CH_NO_ACK(stih415_sbc, _reg, _bit)
+
+#define STIH415_SRST_FRONT(_reg, _bit) \
+	_SYSCFG_RST_CH_NO_ACK(stih415_front, _reg, _bit)
+
+#define STIH415_SRST_LPM(_reg, _bit) \
+	_SYSCFG_RST_CH_NO_ACK(stih415_lpm, _reg, _bit)
+
+#define SYSCFG_114	0x38 /* Powerdown request EMI/NAND/Keyscan */
+#define SYSSTAT_187	0x15c /* Powerdown status EMI/NAND/Keyscan */
+
+#define SYSCFG_336	0x90 /* Powerdown request USB/SATA/PCIe */
+#define SYSSTAT_384	0x150 /* Powerdown status USB/SATA/PCIe */
+
+#define SYSCFG_376	0x130 /* Reset generator 0 control 0 */
+#define SYSCFG_166	0x108 /* Softreset Ethernet 0 */
+#define SYSCFG_31	0x7c /* Softreset Ethernet 1 */
+#define LPM_SYSCFG_1	0x4 /* Softreset IRB */
+
+static const struct syscfg_reset_channel_data stih415_powerdowns[] = {
+	[STIH415_EMISS_POWERDOWN]	= STIH415_PDN_FRONT(0),
+	[STIH415_NAND_POWERDOWN]	= STIH415_PDN_FRONT(1),
+	[STIH415_KEYSCAN_POWERDOWN]	= STIH415_PDN_FRONT(2),
+	[STIH415_USB0_POWERDOWN]	= STIH415_PDN_REAR(0, 0),
+	[STIH415_USB1_POWERDOWN]	= STIH415_PDN_REAR(1, 1),
+	[STIH415_USB2_POWERDOWN]	= STIH415_PDN_REAR(2, 2),
+	[STIH415_SATA0_POWERDOWN]	= STIH415_PDN_REAR(3, 3),
+	[STIH415_SATA1_POWERDOWN]	= STIH415_PDN_REAR(4, 4),
+	[STIH415_PCIE_POWERDOWN]	= STIH415_PDN_REAR(5, 8),
+};
+
+static const struct syscfg_reset_channel_data stih415_softresets[] = {
+	[STIH415_ETH0_SOFTRESET] = STIH415_SRST_FRONT(SYSCFG_166, 0),
+	[STIH415_ETH1_SOFTRESET] = STIH415_SRST_SBC(SYSCFG_31, 0),
+	[STIH415_IRB_SOFTRESET]	 = STIH415_SRST_LPM(LPM_SYSCFG_1, 6),
+	[STIH415_USB0_SOFTRESET] = STIH415_SRST_REAR(SYSCFG_376, 9),
+	[STIH415_USB1_SOFTRESET] = STIH415_SRST_REAR(SYSCFG_376, 10),
+	[STIH415_USB2_SOFTRESET] = STIH415_SRST_REAR(SYSCFG_376, 11),
+};
+
+static struct syscfg_reset_controller_data stih415_powerdown_controller = {
+	.wait_for_ack = true,
+	.nr_channels = ARRAY_SIZE(stih415_powerdowns),
+	.channels = stih415_powerdowns,
+};
+
+static struct syscfg_reset_controller_data stih415_softreset_controller = {
+	.wait_for_ack = false,
+	.active_low = true,
+	.nr_channels = ARRAY_SIZE(stih415_softresets),
+	.channels = stih415_softresets,
+};
+
+static struct of_device_id stih415_reset_match[] = {
+	{ .compatible = "st,stih415-powerdown",
+	  .data = &stih415_powerdown_controller, },
+	{ .compatible = "st,stih415-softreset",
+	  .data = &stih415_softreset_controller, },
+	{},
+};
+
+static struct platform_driver stih415_reset_driver = {
+	.probe = syscfg_reset_probe,
+	.driver = {
+		.name = "reset-stih415",
+		.owner = THIS_MODULE,
+		.of_match_table = stih415_reset_match,
+	},
+};
+
+static int __init stih415_reset_init(void)
+{
+	return platform_driver_register(&stih415_reset_driver);
+}
+arch_initcall(stih415_reset_init);

drivers/reset/sti/reset-stih416.c

@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2013 STMicroelectronics (R&D) Limited
+ * Author: Stephen Gallimore <stephen.gallimore@st.com>
+ * Author: Srinivas Kandagatla <srinivas.kandagatla@st.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/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include <dt-bindings/reset-controller/stih416-resets.h>
+
+#include "reset-syscfg.h"
+
+/*
+ * STiH416 Peripheral powerdown definitions.
+ */
+static const char stih416_front[] = "st,stih416-front-syscfg";
+static const char stih416_rear[] = "st,stih416-rear-syscfg";
+static const char stih416_sbc[] = "st,stih416-sbc-syscfg";
+static const char stih416_lpm[] = "st,stih416-lpm-syscfg";
+static const char stih416_cpu[] = "st,stih416-cpu-syscfg";
+
+#define STIH416_PDN_FRONT(_bit) \
+	_SYSCFG_RST_CH(stih416_front, SYSCFG_1500, _bit, SYSSTAT_1578, _bit)
+
+#define STIH416_PDN_REAR(_cntl, _stat) \
+	_SYSCFG_RST_CH(stih416_rear, SYSCFG_2525, _cntl, SYSSTAT_2583, _stat)
+
+#define SYSCFG_1500	0x7d0 /* Powerdown request EMI/NAND/Keyscan */
+#define SYSSTAT_1578	0x908 /* Powerdown status EMI/NAND/Keyscan */
+
+#define SYSCFG_2525	0x834 /* Powerdown request USB/SATA/PCIe */
+#define SYSSTAT_2583	0x91c /* Powerdown status USB/SATA/PCIe */
+
+#define SYSCFG_2552	0x8A0 /* Reset Generator control 0 */
+#define SYSCFG_1539	0x86c /* Softreset Ethernet 0 */
+#define SYSCFG_510	0x7f8 /* Softreset Ethernet 1 */
+#define LPM_SYSCFG_1	0x4 /* Softreset IRB */
+#define SYSCFG_2553	0x8a4 /* Softreset SATA0/1, PCIE0/1 */
+#define SYSCFG_7563	0x8cc /* MPE softresets 0 */
+#define SYSCFG_7564	0x8d0 /* MPE softresets 1 */
+
+#define STIH416_SRST_CPU(_reg, _bit) \
+	 _SYSCFG_RST_CH_NO_ACK(stih416_cpu, _reg, _bit)
+
+#define STIH416_SRST_FRONT(_reg, _bit) \
+	 _SYSCFG_RST_CH_NO_ACK(stih416_front, _reg, _bit)
+
+#define STIH416_SRST_REAR(_reg, _bit) \
+	 _SYSCFG_RST_CH_NO_ACK(stih416_rear, _reg, _bit)
+
+#define STIH416_SRST_LPM(_reg, _bit) \
+	 _SYSCFG_RST_CH_NO_ACK(stih416_lpm, _reg, _bit)
+
+#define STIH416_SRST_SBC(_reg, _bit) \
+	 _SYSCFG_RST_CH_NO_ACK(stih416_sbc, _reg, _bit)
+
+static const struct syscfg_reset_channel_data stih416_powerdowns[] = {
+	[STIH416_EMISS_POWERDOWN]	= STIH416_PDN_FRONT(0),
+	[STIH416_NAND_POWERDOWN]	= STIH416_PDN_FRONT(1),
+	[STIH416_KEYSCAN_POWERDOWN]	= STIH416_PDN_FRONT(2),
+	[STIH416_USB0_POWERDOWN]	= STIH416_PDN_REAR(0, 0),
+	[STIH416_USB1_POWERDOWN]	= STIH416_PDN_REAR(1, 1),
+	[STIH416_USB2_POWERDOWN]	= STIH416_PDN_REAR(2, 2),
+	[STIH416_USB3_POWERDOWN]	= STIH416_PDN_REAR(6, 5),
+	[STIH416_SATA0_POWERDOWN]	= STIH416_PDN_REAR(3, 3),
+	[STIH416_SATA1_POWERDOWN]	= STIH416_PDN_REAR(4, 4),
+	[STIH416_PCIE0_POWERDOWN]	= STIH416_PDN_REAR(7, 9),
+	[STIH416_PCIE1_POWERDOWN]	= STIH416_PDN_REAR(5, 8),
+};
+
+static const struct syscfg_reset_channel_data stih416_softresets[] = {
+	[STIH416_ETH0_SOFTRESET] = STIH416_SRST_FRONT(SYSCFG_1539, 0),
+	[STIH416_ETH1_SOFTRESET] = STIH416_SRST_SBC(SYSCFG_510, 0),
+	[STIH416_IRB_SOFTRESET]	 = STIH416_SRST_LPM(LPM_SYSCFG_1, 6),
+	[STIH416_USB0_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2552, 9),
+	[STIH416_USB1_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2552, 10),
+	[STIH416_USB2_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2552, 11),
+	[STIH416_USB3_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2552, 28),
+	[STIH416_SATA0_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2553, 7),
+	[STIH416_SATA1_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2553, 3),
+	[STIH416_PCIE0_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2553, 15),
+	[STIH416_PCIE1_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2553, 2),
+	[STIH416_AUD_DAC_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2553, 14),
+	[STIH416_HDTVOUT_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2552, 5),
+	[STIH416_VTAC_M_RX_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2552, 25),
+	[STIH416_VTAC_A_RX_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2552, 26),
+	[STIH416_SYNC_HD_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2553, 5),
+	[STIH416_SYNC_SD_SOFTRESET] = STIH416_SRST_REAR(SYSCFG_2553, 6),
+	[STIH416_BLITTER_SOFTRESET] = STIH416_SRST_CPU(SYSCFG_7563, 10),
+	[STIH416_GPU_SOFTRESET] = STIH416_SRST_CPU(SYSCFG_7563, 11),
+	[STIH416_VTAC_M_TX_SOFTRESET] = STIH416_SRST_CPU(SYSCFG_7563, 18),
+	[STIH416_VTAC_A_TX_SOFTRESET] = STIH416_SRST_CPU(SYSCFG_7563, 19),
+	[STIH416_VTG_AUX_SOFTRESET] = STIH416_SRST_CPU(SYSCFG_7563, 21),
+	[STIH416_JPEG_DEC_SOFTRESET] = STIH416_SRST_CPU(SYSCFG_7563, 23),
+	[STIH416_HVA_SOFTRESET] = STIH416_SRST_CPU(SYSCFG_7564, 2),
+	[STIH416_COMPO_M_SOFTRESET] = STIH416_SRST_CPU(SYSCFG_7564, 3),
+	[STIH416_COMPO_A_SOFTRESET] = STIH416_SRST_CPU(SYSCFG_7564, 4),
+	[STIH416_VP8_DEC_SOFTRESET] = STIH416_SRST_CPU(SYSCFG_7564, 10),
+	[STIH416_VTG_MAIN_SOFTRESET] = STIH416_SRST_CPU(SYSCFG_7564, 16),
+};
+
+static struct syscfg_reset_controller_data stih416_powerdown_controller = {
+	.wait_for_ack	= true,
+	.nr_channels	= ARRAY_SIZE(stih416_powerdowns),
+	.channels	= stih416_powerdowns,
+};
+
+static struct syscfg_reset_controller_data stih416_softreset_controller = {
+	.wait_for_ack = false,
+	.active_low = true,
+	.nr_channels = ARRAY_SIZE(stih416_softresets),
+	.channels = stih416_softresets,
+};
+
+static struct of_device_id stih416_reset_match[] = {
+	{ .compatible = "st,stih416-powerdown",
+	  .data = &stih416_powerdown_controller, },
+	{ .compatible = "st,stih416-softreset",
+	  .data = &stih416_softreset_controller, },
+	{},
+};
+
+static struct platform_driver stih416_reset_driver = {
+	.probe = syscfg_reset_probe,
+	.driver = {
+		.name = "reset-stih416",
+		.owner = THIS_MODULE,
+		.of_match_table = stih416_reset_match,
+	},
+};
+
+static int __init stih416_reset_init(void)
+{
+	return platform_driver_register(&stih416_reset_driver);
+}
+arch_initcall(stih416_reset_init);

drivers/reset/sti/reset-syscfg.c

@@ -0,0 +1,186 @@
+/*
+ * Copyright (C) 2013 STMicroelectronics Limited
+ * Author: Stephen Gallimore <stephen.gallimore@st.com>
+ *
+ * Inspired by mach-imx/src.c
+ *
+ * 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/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#include "reset-syscfg.h"
+
+/**
+ * Reset channel regmap configuration
+ *
+ * @reset: regmap field for the channel's reset bit.
+ * @ack: regmap field for the channel's ack bit (optional).
+ */
+struct syscfg_reset_channel {
+	struct regmap_field *reset;
+	struct regmap_field *ack;
+};
+
+/**
+ * A reset controller which groups together a set of related reset bits, which
+ * may be located in different system configuration registers.
+ *
+ * @rst: base reset controller structure.
+ * @active_low: are the resets in this controller active low, i.e. clearing
+ *              the reset bit puts the hardware into reset.
+ * @channels: An array of reset channels for this controller.
+ */
+struct syscfg_reset_controller {
+	struct reset_controller_dev rst;
+	bool active_low;
+	struct syscfg_reset_channel *channels;
+};
+
+#define to_syscfg_reset_controller(_rst) \
+	container_of(_rst, struct syscfg_reset_controller, rst)
+
+static int syscfg_reset_program_hw(struct reset_controller_dev *rcdev,
+				   unsigned long idx, int assert)
+{
+	struct syscfg_reset_controller *rst = to_syscfg_reset_controller(rcdev);
+	const struct syscfg_reset_channel *ch;
+	u32 ctrl_val = rst->active_low ? !assert : !!assert;
+	int err;
+
+	if (idx >= rcdev->nr_resets)
+		return -EINVAL;
+
+	ch = &rst->channels[idx];
+
+	err = regmap_field_write(ch->reset, ctrl_val);
+	if (err)
+		return err;
+
+	if (ch->ack) {
+		unsigned long timeout = jiffies + msecs_to_jiffies(1000);
+		u32 ack_val;
+
+		while (true) {
+			err = regmap_field_read(ch->ack, &ack_val);
+			if (err)
+				return err;
+
+			if (ack_val == ctrl_val)
+				break;
+
+			if (time_after(jiffies, timeout))
+				return -ETIME;
+
+			cpu_relax();
+		}
+	}
+
+	return 0;
+}
+
+static int syscfg_reset_assert(struct reset_controller_dev *rcdev,
+			       unsigned long idx)
+{
+	return syscfg_reset_program_hw(rcdev, idx, true);
+}
+
+static int syscfg_reset_deassert(struct reset_controller_dev *rcdev,
+				 unsigned long idx)
+{
+	return syscfg_reset_program_hw(rcdev, idx, false);
+}
+
+static int syscfg_reset_dev(struct reset_controller_dev *rcdev,
+			    unsigned long idx)
+{
+	int err = syscfg_reset_assert(rcdev, idx);
+	if (err)
+		return err;
+
+	return syscfg_reset_deassert(rcdev, idx);
+}
+
+static struct reset_control_ops syscfg_reset_ops = {
+	.reset    = syscfg_reset_dev,
+	.assert   = syscfg_reset_assert,
+	.deassert = syscfg_reset_deassert,
+};
+
+static int syscfg_reset_controller_register(struct device *dev,
+				const struct syscfg_reset_controller_data *data)
+{
+	struct syscfg_reset_controller *rc;
+	size_t size;
+	int i, err;
+
+	rc = devm_kzalloc(dev, sizeof(*rc), GFP_KERNEL);
+	if (!rc)
+		return -ENOMEM;
+
+	size = sizeof(struct syscfg_reset_channel) * data->nr_channels;
+
+	rc->channels = devm_kzalloc(dev, size, GFP_KERNEL);
+	if (!rc->channels)
+		return -ENOMEM;
+
+	rc->rst.ops = &syscfg_reset_ops,
+	rc->rst.of_node = dev->of_node;
+	rc->rst.nr_resets = data->nr_channels;
+	rc->active_low = data->active_low;
+
+	for (i = 0; i < data->nr_channels; i++) {
+		struct regmap *map;
+		struct regmap_field *f;
+		const char *compatible = data->channels[i].compatible;
+
+		map = syscon_regmap_lookup_by_compatible(compatible);
+		if (IS_ERR(map))
+			return PTR_ERR(map);
+
+		f = devm_regmap_field_alloc(dev, map, data->channels[i].reset);
+		if (IS_ERR(f))
+			return PTR_ERR(f);
+
+		rc->channels[i].reset = f;
+
+		if (!data->wait_for_ack)
+			continue;
+
+		f = devm_regmap_field_alloc(dev, map, data->channels[i].ack);
+		if (IS_ERR(f))
+			return PTR_ERR(f);
+
+		rc->channels[i].ack = f;
+	}
+
+	err = reset_controller_register(&rc->rst);
+	if (!err)
+		dev_info(dev, "registered\n");
+
+	return err;
+}
+
+int syscfg_reset_probe(struct platform_device *pdev)
+{
+	struct device *dev = pdev ? &pdev->dev : NULL;
+	const struct of_device_id *match;
+
+	if (!dev || !dev->driver)
+		return -ENODEV;
+
+	match = of_match_device(dev->driver->of_match_table, dev);
+	if (!match || !match->data)
+		return -EINVAL;
+
+	return syscfg_reset_controller_register(dev, match->data);
+}

drivers/reset/sti/reset-syscfg.h

@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2013 STMicroelectronics (R&D) Limited
+ * Author: Stephen Gallimore <stephen.gallimore@st.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 __STI_RESET_SYSCFG_H
+#define __STI_RESET_SYSCFG_H
+
+#include <linux/device.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+
+/**
+ * Reset channel description for a system configuration register based
+ * reset controller.
+ *
+ * @compatible: Compatible string of the syscon regmap containing this
+ *              channel's control and ack (status) bits.
+ * @reset: Regmap field description of the channel's reset bit.
+ * @ack: Regmap field description of the channel's acknowledge bit.
+ */
+struct syscfg_reset_channel_data {
+	const char *compatible;
+	struct reg_field reset;
+	struct reg_field ack;
+};
+
+#define _SYSCFG_RST_CH(_c, _rr, _rb, _ar, _ab)		\
+	{ .compatible	= _c,				\
+	  .reset	= REG_FIELD(_rr, _rb, _rb),	\
+	  .ack		= REG_FIELD(_ar, _ab, _ab), }
+
+#define _SYSCFG_RST_CH_NO_ACK(_c, _rr, _rb)		\
+	{ .compatible	= _c,			\
+	  .reset	= REG_FIELD(_rr, _rb, _rb), }
+
+/**
+ * Description of a system configuration register based reset controller.
+ *
+ * @wait_for_ack: The controller will wait for reset assert and de-assert to
+ *                be "ack'd" in a channel's ack field.
+ * @active_low: Are the resets in this controller active low, i.e. clearing
+ *              the reset bit puts the hardware into reset.
+ * @nr_channels: The number of reset channels in this controller.
+ * @channels: An array of reset channel descriptions.
+ */
+struct syscfg_reset_controller_data {
+	bool wait_for_ack;
+	bool active_low;
+	int nr_channels;
+	const struct syscfg_reset_channel_data *channels;
+};
+
+/**
+ * syscfg_reset_probe(): platform device probe function used by syscfg
+ *                       reset controller drivers. This registers a reset
+ *                       controller configured by the OF match data for
+ *                       the compatible device which should be of type
+ *                       "struct syscfg_reset_controller_data".
+ *
+ * @pdev: platform device
+ */
+int syscfg_reset_probe(struct platform_device *pdev);
+
+#endif /* __STI_RESET_SYSCFG_H */