Commit | Line | Data |
---|---|---|
4cf176e5 JQ |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Copyright (C) 2018-2020 Broadcom */ | |
3 | ||
4 | #include <linux/device.h> | |
5 | #include <linux/iopoll.h> | |
6 | #include <linux/module.h> | |
7 | #include <linux/of.h> | |
8 | #include <linux/platform_device.h> | |
9 | #include <linux/reset-controller.h> | |
10 | ||
11 | #define BRCM_RESCAL_START 0x0 | |
12 | #define BRCM_RESCAL_START_BIT BIT(0) | |
13 | #define BRCM_RESCAL_CTRL 0x4 | |
14 | #define BRCM_RESCAL_STATUS 0x8 | |
15 | #define BRCM_RESCAL_STATUS_BIT BIT(0) | |
16 | ||
17 | struct brcm_rescal_reset { | |
18 | void __iomem *base; | |
19 | struct device *dev; | |
20 | struct reset_controller_dev rcdev; | |
21 | }; | |
22 | ||
23 | static int brcm_rescal_reset_set(struct reset_controller_dev *rcdev, | |
24 | unsigned long id) | |
25 | { | |
26 | struct brcm_rescal_reset *data = | |
27 | container_of(rcdev, struct brcm_rescal_reset, rcdev); | |
28 | void __iomem *base = data->base; | |
29 | u32 reg; | |
30 | int ret; | |
31 | ||
32 | reg = readl(base + BRCM_RESCAL_START); | |
33 | writel(reg | BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START); | |
34 | reg = readl(base + BRCM_RESCAL_START); | |
35 | if (!(reg & BRCM_RESCAL_START_BIT)) { | |
36 | dev_err(data->dev, "failed to start SATA/PCIe rescal\n"); | |
37 | return -EIO; | |
38 | } | |
39 | ||
40 | ret = readl_poll_timeout(base + BRCM_RESCAL_STATUS, reg, | |
41 | !(reg & BRCM_RESCAL_STATUS_BIT), 100, 1000); | |
42 | if (ret) { | |
43 | dev_err(data->dev, "time out on SATA/PCIe rescal\n"); | |
44 | return ret; | |
45 | } | |
46 | ||
47 | reg = readl(base + BRCM_RESCAL_START); | |
48 | writel(reg & ~BRCM_RESCAL_START_BIT, base + BRCM_RESCAL_START); | |
49 | ||
50 | dev_dbg(data->dev, "SATA/PCIe rescal success\n"); | |
51 | ||
52 | return 0; | |
53 | } | |
54 | ||
55 | static int brcm_rescal_reset_xlate(struct reset_controller_dev *rcdev, | |
56 | const struct of_phandle_args *reset_spec) | |
57 | { | |
58 | /* This is needed if #reset-cells == 0. */ | |
59 | return 0; | |
60 | } | |
61 | ||
62 | static const struct reset_control_ops brcm_rescal_reset_ops = { | |
63 | .reset = brcm_rescal_reset_set, | |
64 | }; | |
65 | ||
66 | static int brcm_rescal_reset_probe(struct platform_device *pdev) | |
67 | { | |
68 | struct brcm_rescal_reset *data; | |
69 | struct resource *res; | |
70 | ||
71 | data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); | |
72 | if (!data) | |
73 | return -ENOMEM; | |
74 | ||
75 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
76 | data->base = devm_ioremap_resource(&pdev->dev, res); | |
77 | if (IS_ERR(data->base)) | |
78 | return PTR_ERR(data->base); | |
79 | ||
80 | data->rcdev.owner = THIS_MODULE; | |
81 | data->rcdev.nr_resets = 1; | |
82 | data->rcdev.ops = &brcm_rescal_reset_ops; | |
83 | data->rcdev.of_node = pdev->dev.of_node; | |
84 | data->rcdev.of_xlate = brcm_rescal_reset_xlate; | |
85 | data->dev = &pdev->dev; | |
86 | ||
87 | return devm_reset_controller_register(&pdev->dev, &data->rcdev); | |
88 | } | |
89 | ||
90 | static const struct of_device_id brcm_rescal_reset_of_match[] = { | |
91 | { .compatible = "brcm,bcm7216-pcie-sata-rescal" }, | |
92 | { }, | |
93 | }; | |
94 | MODULE_DEVICE_TABLE(of, brcm_rescal_reset_of_match); | |
95 | ||
96 | static struct platform_driver brcm_rescal_reset_driver = { | |
97 | .probe = brcm_rescal_reset_probe, | |
98 | .driver = { | |
99 | .name = "brcm-rescal-reset", | |
100 | .of_match_table = brcm_rescal_reset_of_match, | |
101 | } | |
102 | }; | |
103 | module_platform_driver(brcm_rescal_reset_driver); | |
104 | ||
105 | MODULE_AUTHOR("Broadcom"); | |
106 | MODULE_DESCRIPTION("Broadcom SATA/PCIe rescal reset controller"); | |
107 | MODULE_LICENSE("GPL v2"); |