reset: meson: add meson audio arb driver (d903779b) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/reset/Kconfig

+7 −0

Original line number	Diff line number	Diff line
		@@ -73,6 +73,13 @@ config RESET_MESON
		help
		This enables the reset driver for Amlogic Meson SoCs.

		config RESET_MESON_AUDIO_ARB
		tristate "Meson Audio Memory Arbiter Reset Driver"
		depends on ARCH_MESON \|\| COMPILE_TEST
		help
		This enables the reset driver for Audio Memory Arbiter of
		Amlogic's A113 based SoCs

		config RESET_OXNAS
		bool

drivers/reset/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -12,6 +12,7 @@ obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
		obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o
		obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
		obj-$(CONFIG_RESET_MESON) += reset-meson.o
		obj-$(CONFIG_RESET_MESON_AUDIO_ARB) += reset-meson-audio-arb.o
		obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
		obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o
		obj-$(CONFIG_RESET_QCOM_AOSS) += reset-qcom-aoss.o

drivers/reset/reset-meson-audio-arb.c

0 → 100644

+168 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: (GPL-2.0 OR MIT)
		// Copyright (c) 2018 BayLibre, SAS.
		// Author: Jerome Brunet <jbrunet@baylibre.com>

		#include <linux/clk.h>
		#include <linux/io.h>
		#include <linux/module.h>
		#include <linux/of_platform.h>
		#include <linux/reset-controller.h>
		#include <linux/spinlock.h>

		#include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>

		struct meson_audio_arb_data {
		struct reset_controller_dev rstc;
		void __iomem *regs;
		struct clk *clk;
		const unsigned int *reset_bits;
		spinlock_t lock;
		};

		#define ARB_GENERAL_BIT 31

		static const unsigned int axg_audio_arb_reset_bits[] = {
		[AXG_ARB_TODDR_A] = 0,
		[AXG_ARB_TODDR_B] = 1,
		[AXG_ARB_TODDR_C] = 2,
		[AXG_ARB_FRDDR_A] = 4,
		[AXG_ARB_FRDDR_B] = 5,
		[AXG_ARB_FRDDR_C] = 6,
		};

		static int meson_audio_arb_update(struct reset_controller_dev *rcdev,
		unsigned long id, bool assert)
		{
		u32 val;
		struct meson_audio_arb_data *arb =
		container_of(rcdev, struct meson_audio_arb_data, rstc);

		spin_lock(&arb->lock);
		val = readl(arb->regs);

		if (assert)
		val &= ~BIT(arb->reset_bits[id]);
		else
		val \|= BIT(arb->reset_bits[id]);

		writel(val, arb->regs);
		spin_unlock(&arb->lock);

		return 0;
		}

		static int meson_audio_arb_status(struct reset_controller_dev *rcdev,
		unsigned long id)
		{
		u32 val;
		struct meson_audio_arb_data *arb =
		container_of(rcdev, struct meson_audio_arb_data, rstc);

		val = readl(arb->regs);

		return !(val & BIT(arb->reset_bits[id]));
		}

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

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

		static const struct reset_control_ops meson_audio_arb_rstc_ops = {
		.assert = meson_audio_arb_assert,
		.deassert = meson_audio_arb_deassert,
		.status = meson_audio_arb_status,
		};

		static const struct of_device_id meson_audio_arb_of_match[] = {
		{ .compatible = "amlogic,meson-axg-audio-arb", },
		{}
		};
		MODULE_DEVICE_TABLE(of, meson_audio_arb_of_match);

		static int meson_audio_arb_remove(struct platform_device *pdev)
		{
		struct meson_audio_arb_data *arb = platform_get_drvdata(pdev);

		/* Disable all access */
		spin_lock(&arb->lock);
		writel(0, arb->regs);
		spin_unlock(&arb->lock);

		clk_disable_unprepare(arb->clk);

		return 0;
		}

		static int meson_audio_arb_probe(struct platform_device *pdev)
		{
		struct device *dev = &pdev->dev;
		struct meson_audio_arb_data *arb;
		struct resource *res;
		int ret;

		arb = devm_kzalloc(dev, sizeof(*arb), GFP_KERNEL);
		if (!arb)
		return -ENOMEM;
		platform_set_drvdata(pdev, arb);

		arb->clk = devm_clk_get(dev, NULL);
		if (IS_ERR(arb->clk)) {
		if (PTR_ERR(arb->clk) != -EPROBE_DEFER)
		dev_err(dev, "failed to get clock\n");
		return PTR_ERR(arb->clk);
		}

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		arb->regs = devm_ioremap_resource(dev, res);
		if (IS_ERR(arb->regs))
		return PTR_ERR(arb->regs);

		spin_lock_init(&arb->lock);
		arb->reset_bits = axg_audio_arb_reset_bits;
		arb->rstc.nr_resets = ARRAY_SIZE(axg_audio_arb_reset_bits);
		arb->rstc.ops = &meson_audio_arb_rstc_ops;
		arb->rstc.of_node = dev->of_node;

		/*
		* Enable general :
		* In the initial state, all memory interfaces are disabled
		* and the general bit is on
		*/
		ret = clk_prepare_enable(arb->clk);
		if (ret) {
		dev_err(dev, "failed to enable arb clock\n");
		return ret;
		}
		writel(BIT(ARB_GENERAL_BIT), arb->regs);

		/* Register reset controller */
		ret = devm_reset_controller_register(dev, &arb->rstc);
		if (ret) {
		dev_err(dev, "failed to register arb reset controller\n");
		meson_audio_arb_remove(pdev);
		}

		return ret;
		}

		static struct platform_driver meson_audio_arb_pdrv = {
		.probe = meson_audio_arb_probe,
		.remove = meson_audio_arb_remove,
		.driver = {
		.name = "meson-audio-arb-reset",
		.of_match_table = meson_audio_arb_of_match,
		},
		};
		module_platform_driver(meson_audio_arb_pdrv);

		MODULE_DESCRIPTION("Amlogic A113 Audio Memory Arbiter");
		MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
		MODULE_LICENSE("GPL v2");