1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright Intel Corporation (C) 2017. All Rights Reserved 4 * 5 * Reset driver for Altera Arria10 MAX5 System Resource Chip 6 * 7 * Adapted from reset-socfpga.c 8 */ 9 10 #include <linux/err.h> 11 #include <linux/mfd/altera-a10sr.h> 12 #include <linux/module.h> 13 #include <linux/of.h> 14 #include <linux/platform_device.h> 15 #include <linux/reset-controller.h> 16 17 #include <dt-bindings/reset/altr,rst-mgr-a10sr.h> 18 19 struct a10sr_reset { 20 struct reset_controller_dev rcdev; 21 struct regmap *regmap; 22 }; 23 24 static inline struct a10sr_reset *to_a10sr_rst(struct reset_controller_dev *rc) 25 { 26 return container_of(rc, struct a10sr_reset, rcdev); 27 } 28 29 static inline int a10sr_reset_shift(unsigned long id) 30 { 31 switch (id) { 32 case A10SR_RESET_ENET_HPS: 33 return 1; 34 case A10SR_RESET_PCIE: 35 case A10SR_RESET_FILE: 36 case A10SR_RESET_BQSPI: 37 case A10SR_RESET_USB: 38 return id + 11; 39 default: 40 return -EINVAL; 41 } 42 } 43 44 static int a10sr_reset_update(struct reset_controller_dev *rcdev, 45 unsigned long id, bool assert) 46 { 47 struct a10sr_reset *a10r = to_a10sr_rst(rcdev); 48 int offset = a10sr_reset_shift(id); 49 u8 mask = ALTR_A10SR_REG_BIT_MASK(offset); 50 int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset); 51 52 return regmap_update_bits(a10r->regmap, index, mask, assert ? 0 : mask); 53 } 54 55 static int a10sr_reset_assert(struct reset_controller_dev *rcdev, 56 unsigned long id) 57 { 58 return a10sr_reset_update(rcdev, id, true); 59 } 60 61 static int a10sr_reset_deassert(struct reset_controller_dev *rcdev, 62 unsigned long id) 63 { 64 return a10sr_reset_update(rcdev, id, false); 65 } 66 67 static int a10sr_reset_status(struct reset_controller_dev *rcdev, 68 unsigned long id) 69 { 70 int ret; 71 struct a10sr_reset *a10r = to_a10sr_rst(rcdev); 72 int offset = a10sr_reset_shift(id); 73 u8 mask = ALTR_A10SR_REG_BIT_MASK(offset); 74 int index = ALTR_A10SR_HPS_RST_REG + ALTR_A10SR_REG_OFFSET(offset); 75 unsigned int value; 76 77 ret = regmap_read(a10r->regmap, index, &value); 78 if (ret < 0) 79 return ret; 80 81 return !!(value & mask); 82 } 83 84 static const struct reset_control_ops a10sr_reset_ops = { 85 .assert = a10sr_reset_assert, 86 .deassert = a10sr_reset_deassert, 87 .status = a10sr_reset_status, 88 }; 89 90 static int a10sr_reset_probe(struct platform_device *pdev) 91 { 92 struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent); 93 struct a10sr_reset *a10r; 94 95 a10r = devm_kzalloc(&pdev->dev, sizeof(struct a10sr_reset), 96 GFP_KERNEL); 97 if (!a10r) 98 return -ENOMEM; 99 100 a10r->rcdev.owner = THIS_MODULE; 101 a10r->rcdev.nr_resets = A10SR_RESET_NUM; 102 a10r->rcdev.ops = &a10sr_reset_ops; 103 a10r->rcdev.of_node = pdev->dev.of_node; 104 a10r->regmap = a10sr->regmap; 105 106 platform_set_drvdata(pdev, a10r); 107 108 return devm_reset_controller_register(&pdev->dev, &a10r->rcdev); 109 } 110 111 static const struct of_device_id a10sr_reset_of_match[] = { 112 { .compatible = "altr,a10sr-reset" }, 113 { }, 114 }; 115 MODULE_DEVICE_TABLE(of, a10sr_reset_of_match); 116 117 static struct platform_driver a10sr_reset_driver = { 118 .probe = a10sr_reset_probe, 119 .driver = { 120 .name = "altr_a10sr_reset", 121 }, 122 }; 123 module_platform_driver(a10sr_reset_driver); 124 125 MODULE_AUTHOR("Thor Thayer <thor.thayer@linux.intel.com>"); 126 MODULE_DESCRIPTION("Altera Arria10 System Resource Reset Controller Driver"); 127 MODULE_LICENSE("GPL v2"); 128