drivers/reset/reset-qcom-aoss.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2018 The Linux Foundation. All rights reserved.
   4  */
   5
   6 #include <linux/module.h>
   7 #include <linux/platform_device.h>
   8 #include <linux/reset-controller.h>
   9 #include <linux/delay.h>
  10 #include <linux/io.h>
  11 #include <linux/of_device.h>
  12 #include <dt-bindings/reset/qcom,sdm845-aoss.h>
  13
  14 struct qcom_aoss_reset_map {
  15         unsigned int reg;
  16 };
  17
  18 struct qcom_aoss_desc {
  19         const struct qcom_aoss_reset_map *resets;
  20         size_t num_resets;
  21 };
  22
  23 struct qcom_aoss_reset_data {
  24         struct reset_controller_dev rcdev;
  25         void __iomem *base;
  26         const struct qcom_aoss_desc *desc;
  27 };
  28
  29 static const struct qcom_aoss_reset_map sdm845_aoss_resets[] = {
  30         [AOSS_CC_MSS_RESTART] = {0x10000},
  31         [AOSS_CC_CAMSS_RESTART] = {0x11000},
  32         [AOSS_CC_VENUS_RESTART] = {0x12000},
  33         [AOSS_CC_GPU_RESTART] = {0x13000},
  34         [AOSS_CC_DISPSS_RESTART] = {0x14000},
  35         [AOSS_CC_WCSS_RESTART] = {0x20000},
  36         [AOSS_CC_LPASS_RESTART] = {0x30000},
  37 };
  38
  39 static const struct qcom_aoss_desc sdm845_aoss_desc = {
  40         .resets = sdm845_aoss_resets,
  41         .num_resets = ARRAY_SIZE(sdm845_aoss_resets),
  42 };
  43
  44 static inline struct qcom_aoss_reset_data *to_qcom_aoss_reset_data(
  45                                 struct reset_controller_dev *rcdev)
  46 {
  47         return container_of(rcdev, struct qcom_aoss_reset_data, rcdev);
  48 }
  49
  50 static int qcom_aoss_control_assert(struct reset_controller_dev *rcdev,
  51                                     unsigned long idx)
  52 {
  53         struct qcom_aoss_reset_data *data = to_qcom_aoss_reset_data(rcdev);
  54         const struct qcom_aoss_reset_map *map = &data->desc->resets[idx];
  55
  56         writel(1, data->base + map->reg);
  57         /* Wait 6 32kHz sleep cycles for reset */
  58         usleep_range(200, 300);
  59         return 0;
  60 }
  61
  62 static int qcom_aoss_control_deassert(struct reset_controller_dev *rcdev,
  63                                       unsigned long idx)
  64 {
  65         struct qcom_aoss_reset_data *data = to_qcom_aoss_reset_data(rcdev);
  66         const struct qcom_aoss_reset_map *map = &data->desc->resets[idx];
  67
  68         writel(0, data->base + map->reg);
  69         /* Wait 6 32kHz sleep cycles for reset */
  70         usleep_range(200, 300);
  71         return 0;
  72 }
  73
  74 static int qcom_aoss_control_reset(struct reset_controller_dev *rcdev,
  75                                         unsigned long idx)
  76 {
  77         qcom_aoss_control_assert(rcdev, idx);
  78
  79         return qcom_aoss_control_deassert(rcdev, idx);
  80 }
  81
  82 static const struct reset_control_ops qcom_aoss_reset_ops = {
  83         .reset = qcom_aoss_control_reset,
  84         .assert = qcom_aoss_control_assert,
  85         .deassert = qcom_aoss_control_deassert,
  86 };
  87
  88 static int qcom_aoss_reset_probe(struct platform_device *pdev)
  89 {
  90         struct qcom_aoss_reset_data *data;
  91         struct device *dev = &pdev->dev;
  92         const struct qcom_aoss_desc *desc;
  93         struct resource *res;
  94
  95         desc = of_device_get_match_data(dev);
  96         if (!desc)
  97                 return -EINVAL;
  98
  99         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 100         if (!data)
 101                 return -ENOMEM;
 102
 103         data->desc = desc;
 104         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 105         data->base = devm_ioremap_resource(dev, res);
 106         if (IS_ERR(data->base))
 107                 return PTR_ERR(data->base);
 108
 109         data->rcdev.owner = THIS_MODULE;
 110         data->rcdev.ops = &qcom_aoss_reset_ops;
 111         data->rcdev.nr_resets = desc->num_resets;
 112         data->rcdev.of_node = dev->of_node;
 113
 114         return devm_reset_controller_register(dev, &data->rcdev);
 115 }
 116
 117 static const struct of_device_id qcom_aoss_reset_of_match[] = {
 118         { .compatible = "qcom,sdm845-aoss-cc", .data = &sdm845_aoss_desc },
 119         {}
 120 };
 121
 122 static struct platform_driver qcom_aoss_reset_driver = {
 123         .probe = qcom_aoss_reset_probe,
 124         .driver  = {
 125                 .name = "qcom_aoss_reset",
 126                 .of_match_table = qcom_aoss_reset_of_match,
 127         },
 128 };
 129
 130 builtin_platform_driver(qcom_aoss_reset_driver);
 131
 132 MODULE_DESCRIPTION("Qualcomm AOSS Reset Driver");
 133 MODULE_LICENSE("GPL v2");