soc: amlogic: meson-mx-secbus2: Add a driver for SECBUS2 register access - WiP

	  Say yes to expose Amlogic Meson Everything-Else Power Domains as

	  Generic Power Domains.

config MESON_MX_SECBUS2

	tristate "Amlogic Meson6/8/8b/8m2 SECBUS2 driver"

	depends on (ARM && ARCH_MESON) || COMPILE_TEST

	select REGMAP_MMIO

	help

	  Say yes to have support for the SECBUS2 registers on

	  Amlogic Meson6, Meson8, Meson8b and Meson8m2 SoCs.

config MESON_SECURE_PM_DOMAINS

	tristate "Amlogic Meson Secure Power Domains driver"

	depends on (ARCH_MESON || COMPILE_TEST) && MESON_SM

obj-$(CONFIG_MESON_CLK_MEASURE) += meson-clk-measure.o

obj-$(CONFIG_MESON_GX_SOCINFO) += meson-gx-socinfo.o

obj-$(CONFIG_MESON_GX_PM_DOMAINS) += meson-gx-pwrc-vpu.o

obj-$(CONFIG_MESON_MX_SECBUS2) += meson-mx-secbus2.o

obj-$(CONFIG_MESON_MX_SOCINFO) += meson-mx-socinfo.o

obj-$(CONFIG_MESON_EE_PM_DOMAINS) += meson-ee-pwrc.o

obj-$(CONFIG_MESON_SECURE_PM_DOMAINS) += meson-secure-pwrc.o

/*

 * Amlogic SECBUS2 register access driver. The registers can be accessed

 * directly when not running in "secure mode". When "secure mode" is enabled

 * then these registers have to be accessed through secure monitor calls.

 * TODO: secure monitor operations are not implemented yet.

 *

 * Copyright (c) 2020 Martin Blumenstingl <martin.blumenstingl@googlemail.com>

 *

 * SPDX-License-Identifier: GPL-2.0-or-later

 */

#include <linux/device.h>

#include <linux/module.h>

#include <linux/mod_devicetable.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>

#include <linux/resource.h>

static const struct regmap_config meson_mx_secbus2_raw_regmap_conf = {

	.reg_bits = 16,

	.val_bits = 32,

	.reg_stride = 4,

	.max_register = 0x38,

};

static int meson_mx_secbus2_probe(struct platform_device *pdev)

{

	struct regmap *regmap;

	struct resource *res;

	void __iomem *base;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	base = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(base))

		return PTR_ERR(base);

	regmap = devm_regmap_init_mmio(&pdev->dev, base,

				       &meson_mx_secbus2_raw_regmap_conf);

	return PTR_ERR_OR_ZERO(regmap);

}

static const struct of_device_id meson_mx_secbus2_match[] = {

	{ .compatible = "amlogic,meson-mx-secbus2" },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, meson_mx_secbus2_match);

static struct platform_driver meson_mx_secbus2_driver = {

	.probe = meson_mx_secbus2_probe,

	.driver = {

		.name = "meson-mx-secbus2",

		.of_match_table = of_match_ptr(meson_mx_secbus2_match),

	},

};

module_platform_driver(meson_mx_secbus2_driver);

MODULE_DESCRIPTION("Amlogic Meson6/8/8b/8m2 SECBUS2 driver");

MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");

MODULE_LICENSE("GPL v2");