cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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reset-pistachio.c (3357B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Pistachio SoC Reset Controller driver
      4 *
      5 * Copyright (C) 2015 Imagination Technologies Ltd.
      6 *
      7 * Author: Damien Horsley <Damien.Horsley@imgtec.com>
      8 */
      9
     10#include <linux/init.h>
     11#include <linux/of.h>
     12#include <linux/platform_device.h>
     13#include <linux/regmap.h>
     14#include <linux/reset-controller.h>
     15#include <linux/slab.h>
     16#include <linux/mfd/syscon.h>
     17
     18#include <dt-bindings/reset/pistachio-resets.h>
     19
     20#define	PISTACHIO_SOFT_RESET		0
     21
     22struct pistachio_reset_data {
     23	struct reset_controller_dev	rcdev;
     24	struct regmap			*periph_regs;
     25};
     26
     27static inline int pistachio_reset_shift(unsigned long id)
     28{
     29	switch (id) {
     30	case PISTACHIO_RESET_I2C0:
     31	case PISTACHIO_RESET_I2C1:
     32	case PISTACHIO_RESET_I2C2:
     33	case PISTACHIO_RESET_I2C3:
     34	case PISTACHIO_RESET_I2S_IN:
     35	case PISTACHIO_RESET_PRL_OUT:
     36	case PISTACHIO_RESET_SPDIF_OUT:
     37	case PISTACHIO_RESET_SPI:
     38	case PISTACHIO_RESET_PWM_PDM:
     39	case PISTACHIO_RESET_UART0:
     40	case PISTACHIO_RESET_UART1:
     41	case PISTACHIO_RESET_QSPI:
     42	case PISTACHIO_RESET_MDC:
     43	case PISTACHIO_RESET_SDHOST:
     44	case PISTACHIO_RESET_ETHERNET:
     45	case PISTACHIO_RESET_IR:
     46	case PISTACHIO_RESET_HASH:
     47	case PISTACHIO_RESET_TIMER:
     48		return id;
     49	case PISTACHIO_RESET_I2S_OUT:
     50	case PISTACHIO_RESET_SPDIF_IN:
     51	case PISTACHIO_RESET_EVT:
     52		return id + 6;
     53	case PISTACHIO_RESET_USB_H:
     54	case PISTACHIO_RESET_USB_PR:
     55	case PISTACHIO_RESET_USB_PHY_PR:
     56	case PISTACHIO_RESET_USB_PHY_PON:
     57		return id + 7;
     58	default:
     59		return -EINVAL;
     60	}
     61}
     62
     63static int pistachio_reset_assert(struct reset_controller_dev *rcdev,
     64				  unsigned long id)
     65{
     66	struct pistachio_reset_data *rd;
     67	u32 mask;
     68	int shift;
     69
     70	rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
     71	shift = pistachio_reset_shift(id);
     72	if (shift < 0)
     73		return shift;
     74	mask = BIT(shift);
     75
     76	return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
     77				  mask, mask);
     78}
     79
     80static int pistachio_reset_deassert(struct reset_controller_dev *rcdev,
     81				    unsigned long id)
     82{
     83	struct pistachio_reset_data *rd;
     84	u32 mask;
     85	int shift;
     86
     87	rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
     88	shift = pistachio_reset_shift(id);
     89	if (shift < 0)
     90		return shift;
     91	mask = BIT(shift);
     92
     93	return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
     94				  mask, 0);
     95}
     96
     97static const struct reset_control_ops pistachio_reset_ops = {
     98	.assert		= pistachio_reset_assert,
     99	.deassert	= pistachio_reset_deassert,
    100};
    101
    102static int pistachio_reset_probe(struct platform_device *pdev)
    103{
    104	struct pistachio_reset_data *rd;
    105	struct device *dev = &pdev->dev;
    106	struct device_node *np = pdev->dev.of_node;
    107
    108	rd = devm_kzalloc(dev, sizeof(*rd), GFP_KERNEL);
    109	if (!rd)
    110		return -ENOMEM;
    111
    112	rd->periph_regs = syscon_node_to_regmap(np->parent);
    113	if (IS_ERR(rd->periph_regs))
    114		return PTR_ERR(rd->periph_regs);
    115
    116	rd->rcdev.owner = THIS_MODULE;
    117	rd->rcdev.nr_resets = PISTACHIO_RESET_MAX + 1;
    118	rd->rcdev.ops = &pistachio_reset_ops;
    119	rd->rcdev.of_node = np;
    120
    121	return devm_reset_controller_register(dev, &rd->rcdev);
    122}
    123
    124static const struct of_device_id pistachio_reset_dt_ids[] = {
    125	 { .compatible = "img,pistachio-reset", },
    126	 { /* sentinel */ },
    127};
    128
    129static struct platform_driver pistachio_reset_driver = {
    130	.probe	= pistachio_reset_probe,
    131	.driver = {
    132		.name		= "pistachio-reset",
    133		.of_match_table	= pistachio_reset_dt_ids,
    134	},
    135};
    136builtin_platform_driver(pistachio_reset_driver);