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linux/drivers/reset/starfive/reset-starfive-jh7100.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Reset driver for the StarFive JH7100 SoC
*
* Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk>
*/
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include "reset-starfive-jh71x0.h"
#include <dt-bindings/reset/starfive-jh7100.h>
/* register offsets */
#define JH7100_RESET_ASSERT0 0x00
#define JH7100_RESET_ASSERT1 0x04
#define JH7100_RESET_ASSERT2 0x08
#define JH7100_RESET_ASSERT3 0x0c
#define JH7100_RESET_STATUS0 0x10
#define JH7100_RESET_STATUS1 0x14
#define JH7100_RESET_STATUS2 0x18
#define JH7100_RESET_STATUS3 0x1c
/*
* Writing a 1 to the n'th bit of the m'th ASSERT register asserts
* line 32m + n, and writing a 0 deasserts the same line.
* Most reset lines have their status inverted so a 0 bit in the STATUS
* register means the line is asserted and a 1 means it's deasserted. A few
* lines don't though, so store the expected value of the status registers when
* all lines are asserted.
*/
static const u32 jh7100_reset_asserted[4] = {
/* STATUS0 */
BIT(JH7100_RST_U74 % 32) |
BIT(JH7100_RST_VP6_DRESET % 32) |
BIT(JH7100_RST_VP6_BRESET % 32),
/* STATUS1 */
BIT(JH7100_RST_HIFI4_DRESET % 32) |
BIT(JH7100_RST_HIFI4_BRESET % 32),
/* STATUS2 */
BIT(JH7100_RST_E24 % 32),
/* STATUS3 */
0,
};
static int __init jh7100_reset_probe(struct platform_device *pdev)
{
void __iomem *base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
return reset_starfive_jh71x0_register(&pdev->dev, pdev->dev.of_node,
base + JH7100_RESET_ASSERT0,
base + JH7100_RESET_STATUS0,
jh7100_reset_asserted,
JH7100_RSTN_END,
THIS_MODULE);
}
static const struct of_device_id jh7100_reset_dt_ids[] = {
{ .compatible = "starfive,jh7100-reset" },
{ /* sentinel */ }
};
static struct platform_driver jh7100_reset_driver = {
.driver = {
.name = "jh7100-reset",
.of_match_table = jh7100_reset_dt_ids,
.suppress_bind_attrs = true,
},
};
builtin_platform_driver_probe(jh7100_reset_driver, jh7100_reset_probe);