Damien Horsley | 8a56736 | 2016-01-18 13:12:38 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Pistachio SoC Reset Controller driver |
| 3 | * |
| 4 | * Copyright (C) 2015 Imagination Technologies Ltd. |
| 5 | * |
| 6 | * Author: Damien Horsley <Damien.Horsley@imgtec.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify it |
| 9 | * under the terms and conditions of the GNU General Public License, |
| 10 | * version 2, as published by the Free Software Foundation. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/of.h> |
| 15 | #include <linux/platform_device.h> |
| 16 | #include <linux/regmap.h> |
| 17 | #include <linux/reset-controller.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/mfd/syscon.h> |
| 20 | |
| 21 | #include <dt-bindings/reset/pistachio-resets.h> |
| 22 | |
| 23 | #define PISTACHIO_SOFT_RESET 0 |
| 24 | |
| 25 | struct pistachio_reset_data { |
| 26 | struct reset_controller_dev rcdev; |
| 27 | struct regmap *periph_regs; |
| 28 | }; |
| 29 | |
| 30 | static inline int pistachio_reset_shift(unsigned long id) |
| 31 | { |
| 32 | switch (id) { |
| 33 | case PISTACHIO_RESET_I2C0: |
| 34 | case PISTACHIO_RESET_I2C1: |
| 35 | case PISTACHIO_RESET_I2C2: |
| 36 | case PISTACHIO_RESET_I2C3: |
| 37 | case PISTACHIO_RESET_I2S_IN: |
| 38 | case PISTACHIO_RESET_PRL_OUT: |
| 39 | case PISTACHIO_RESET_SPDIF_OUT: |
| 40 | case PISTACHIO_RESET_SPI: |
| 41 | case PISTACHIO_RESET_PWM_PDM: |
| 42 | case PISTACHIO_RESET_UART0: |
| 43 | case PISTACHIO_RESET_UART1: |
| 44 | case PISTACHIO_RESET_QSPI: |
| 45 | case PISTACHIO_RESET_MDC: |
| 46 | case PISTACHIO_RESET_SDHOST: |
| 47 | case PISTACHIO_RESET_ETHERNET: |
| 48 | case PISTACHIO_RESET_IR: |
| 49 | case PISTACHIO_RESET_HASH: |
| 50 | case PISTACHIO_RESET_TIMER: |
| 51 | return id; |
| 52 | case PISTACHIO_RESET_I2S_OUT: |
| 53 | case PISTACHIO_RESET_SPDIF_IN: |
| 54 | case PISTACHIO_RESET_EVT: |
| 55 | return id + 6; |
| 56 | case PISTACHIO_RESET_USB_H: |
| 57 | case PISTACHIO_RESET_USB_PR: |
| 58 | case PISTACHIO_RESET_USB_PHY_PR: |
| 59 | case PISTACHIO_RESET_USB_PHY_PON: |
| 60 | return id + 7; |
| 61 | default: |
| 62 | return -EINVAL; |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | static int pistachio_reset_assert(struct reset_controller_dev *rcdev, |
| 67 | unsigned long id) |
| 68 | { |
| 69 | struct pistachio_reset_data *rd; |
| 70 | u32 mask; |
| 71 | int shift; |
| 72 | |
| 73 | rd = container_of(rcdev, struct pistachio_reset_data, rcdev); |
| 74 | shift = pistachio_reset_shift(id); |
| 75 | if (shift < 0) |
| 76 | return shift; |
| 77 | mask = BIT(shift); |
| 78 | |
| 79 | return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET, |
| 80 | mask, mask); |
| 81 | } |
| 82 | |
| 83 | static int pistachio_reset_deassert(struct reset_controller_dev *rcdev, |
| 84 | unsigned long id) |
| 85 | { |
| 86 | struct pistachio_reset_data *rd; |
| 87 | u32 mask; |
| 88 | int shift; |
| 89 | |
| 90 | rd = container_of(rcdev, struct pistachio_reset_data, rcdev); |
| 91 | shift = pistachio_reset_shift(id); |
| 92 | if (shift < 0) |
| 93 | return shift; |
| 94 | mask = BIT(shift); |
| 95 | |
| 96 | return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET, |
| 97 | mask, 0); |
| 98 | } |
| 99 | |
| 100 | static struct reset_control_ops pistachio_reset_ops = { |
| 101 | .assert = pistachio_reset_assert, |
| 102 | .deassert = pistachio_reset_deassert, |
| 103 | }; |
| 104 | |
| 105 | static int pistachio_reset_probe(struct platform_device *pdev) |
| 106 | { |
| 107 | struct pistachio_reset_data *rd; |
| 108 | struct device *dev = &pdev->dev; |
| 109 | struct device_node *np = pdev->dev.of_node; |
| 110 | |
| 111 | rd = devm_kzalloc(dev, sizeof(*rd), GFP_KERNEL); |
| 112 | if (!rd) |
| 113 | return -ENOMEM; |
| 114 | |
| 115 | rd->periph_regs = syscon_node_to_regmap(np->parent); |
| 116 | if (IS_ERR(rd->periph_regs)) |
| 117 | return PTR_ERR(rd->periph_regs); |
| 118 | |
| 119 | rd->rcdev.owner = THIS_MODULE; |
| 120 | rd->rcdev.nr_resets = PISTACHIO_RESET_MAX + 1; |
| 121 | rd->rcdev.ops = &pistachio_reset_ops; |
| 122 | rd->rcdev.of_node = np; |
| 123 | |
| 124 | return reset_controller_register(&rd->rcdev); |
| 125 | } |
| 126 | |
| 127 | static int pistachio_reset_remove(struct platform_device *pdev) |
| 128 | { |
| 129 | struct pistachio_reset_data *data = platform_get_drvdata(pdev); |
| 130 | |
| 131 | reset_controller_unregister(&data->rcdev); |
| 132 | |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | static const struct of_device_id pistachio_reset_dt_ids[] = { |
| 137 | { .compatible = "img,pistachio-reset", }, |
| 138 | { /* sentinel */ }, |
| 139 | }; |
| 140 | MODULE_DEVICE_TABLE(of, pistachio_reset_dt_ids); |
| 141 | |
| 142 | static struct platform_driver pistachio_reset_driver = { |
| 143 | .probe = pistachio_reset_probe, |
| 144 | .remove = pistachio_reset_remove, |
| 145 | .driver = { |
| 146 | .name = "pistachio-reset", |
| 147 | .of_match_table = pistachio_reset_dt_ids, |
| 148 | }, |
| 149 | }; |
| 150 | module_platform_driver(pistachio_reset_driver); |
| 151 | |
| 152 | MODULE_AUTHOR("Damien Horsley <Damien.Horsley@imgtec.com>"); |
| 153 | MODULE_DESCRIPTION("Pistacho Reset Controller Driver"); |
| 154 | MODULE_LICENSE("GPL v2"); |