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 22 struct pistachio_reset_data { 23 struct reset_controller_dev rcdev; 24 struct regmap *periph_regs; 25 }; 26 27 static 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 63 static 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 80 static 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 97 static const struct reset_control_ops pistachio_reset_ops = { 98 .assert = pistachio_reset_assert, 99 .deassert = pistachio_reset_deassert, 100 }; 101 102 static 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 } 123 124 static const struct of_device_id pistachio_reset_dt_ids[] = { 125 { .compatible = "img,pistachio-reset", }, 126 { /* sentinel */ }, 127 }; 128 129 static 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 }; 136 builtin_platform_driver(pistachio_reset_driver); 137