reset: Add Altera Arria10 SR Reset Controller (62700682) · Commits · e / devices / android_kernel_teracube_emerald

MAINTAINERS

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		@@ -653,6 +653,7 @@ M: Thor Thayer <thor.thayer@linux.intel.com>
		S: Maintained
		F: drivers/gpio/gpio-altera-a10sr.c
		F: drivers/mfd/altera-a10sr.c
		F: drivers/reset/reset-a10sr.c
		F: include/linux/mfd/altera-a10sr.h
		F: include/dt-bindings/reset/altr,rst-mgr-a10sr.h

drivers/reset/Kconfig

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		@@ -14,6 +14,13 @@ menuconfig RESET_CONTROLLER

		if RESET_CONTROLLER

		config RESET_A10SR
		tristate "Altera Arria10 System Resource Reset"
		depends on MFD_ALTERA_A10SR
		help
		This option enables support for the external reset functions for
		peripheral PHYs on the Altera Arria10 System Resource Chip.

		config RESET_ATH79
		bool "AR71xx Reset Driver" if COMPILE_TEST
		default ATH79

drivers/reset/Makefile

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		@@ -2,6 +2,7 @@ obj-y += core.o
		obj-y += hisilicon/
		obj-$(CONFIG_ARCH_STI) += sti/
		obj-$(CONFIG_ARCH_TEGRA) += tegra/
		obj-$(CONFIG_RESET_A10SR) += reset-a10sr.o
		obj-$(CONFIG_RESET_ATH79) += reset-ath79.o
		obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
		obj-$(CONFIG_RESET_IMX7) += reset-imx7.o

drivers/reset/reset-a10sr.c

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		/*
		* Copyright Intel Corporation (C) 2017. All Rights Reserved
		*
		* 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.
		*
		* This program is distributed in the hope 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.
		*
		* You should have received a copy of the GNU General Public License along with
		* this program. If not, see <http://www.gnu.org/licenses/>.
		*
		* Reset driver for Altera Arria10 MAX5 System Resource Chip
		*
		* Adapted from reset-socfpga.c
		*/

		#include <linux/err.h>
		#include <linux/mfd/altera-a10sr.h>
		#include <linux/module.h>
		#include <linux/of.h>
		#include <linux/platform_device.h>
		#include <linux/reset-controller.h>

		#include <dt-bindings/reset/altr,rst-mgr-a10sr.h>

		struct a10sr_reset {
		struct reset_controller_dev rcdev;
		struct regmap *regmap;
		};

		static inline struct a10sr_reset to_a10sr_rst(struct reset_controller_dev rc)
		{
		return container_of(rc, struct a10sr_reset, rcdev);
		}

		static inline int a10sr_reset_shift(unsigned long id)
		{
		switch (id) {
		case A10SR_RESET_ENET_HPS:
		return 1;
		case A10SR_RESET_PCIE:
		case A10SR_RESET_FILE:
		case A10SR_RESET_BQSPI:
		case A10SR_RESET_USB:
		return id + 11;
		default:
		return -EINVAL;
		}
		}

		static int a10sr_reset_update(struct reset_controller_dev *rcdev,
		unsigned long id, bool assert)
		{
		struct a10sr_reset *a10r = to_a10sr_rst(rcdev);
		int offset = a10sr_reset_shift(id);
		u8 mask = ALTR_A10SR_REG_BIT_MASK(offset);
		int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset);

		return regmap_update_bits(a10r->regmap, index, mask, assert ? 0 : mask);
		}

		static int a10sr_reset_assert(struct reset_controller_dev *rcdev,
		unsigned long id)
		{
		return a10sr_reset_update(rcdev, id, true);
		}

		static int a10sr_reset_deassert(struct reset_controller_dev *rcdev,
		unsigned long id)
		{
		return a10sr_reset_update(rcdev, id, false);
		}

		static int a10sr_reset_status(struct reset_controller_dev *rcdev,
		unsigned long id)
		{
		int ret;
		struct a10sr_reset *a10r = to_a10sr_rst(rcdev);
		int offset = a10sr_reset_shift(id);
		u8 mask = ALTR_A10SR_REG_BIT_MASK(offset);
		int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset);
		unsigned int value;

		ret = regmap_read(a10r->regmap, index, &value);
		if (ret < 0)
		return ret;

		return !!(value & mask);
		}

		static const struct reset_control_ops a10sr_reset_ops = {
		.assert = a10sr_reset_assert,
		.deassert = a10sr_reset_deassert,
		.status = a10sr_reset_status,
		};

		static int a10sr_reset_probe(struct platform_device *pdev)
		{
		struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent);
		struct a10sr_reset *a10r;

		a10r = devm_kzalloc(&pdev->dev, sizeof(struct a10sr_reset),
		GFP_KERNEL);
		if (!a10r)
		return -ENOMEM;

		a10r->rcdev.owner = THIS_MODULE;
		a10r->rcdev.nr_resets = A10SR_RESET_NUM;
		a10r->rcdev.ops = &a10sr_reset_ops;
		a10r->rcdev.of_node = pdev->dev.of_node;
		a10r->regmap = a10sr->regmap;

		platform_set_drvdata(pdev, a10r);

		return devm_reset_controller_register(&pdev->dev, &a10r->rcdev);
		}

		static const struct of_device_id a10sr_reset_of_match[] = {
		{ .compatible = "altr,a10sr-reset" },
		{ },
		};
		MODULE_DEVICE_TABLE(of, a10sr_reset_of_match);

		static struct platform_driver a10sr_reset_driver = {
		.probe = a10sr_reset_probe,
		.driver = {
		.name = "altr_a10sr_reset",
		},
		};
		module_platform_driver(a10sr_reset_driver);

		MODULE_AUTHOR("Thor Thayer <thor.thayer@linux.intel.com>");
		MODULE_DESCRIPTION("Altera Arria10 System Resource Reset Controller Driver");
		MODULE_LICENSE("GPL v2");