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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Pistachio SoC Reset Controller driver4 *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 021 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);137