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(addr: base + BRCM_RESCAL_START); |
33 | writel(val: reg | BRCM_RESCAL_START_BIT, addr: base + BRCM_RESCAL_START); |
34 | reg = readl(addr: 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(addr: base + BRCM_RESCAL_START); |
48 | writel(val: reg & ~BRCM_RESCAL_START_BIT, addr: 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 | |
70 | data = devm_kzalloc(dev: &pdev->dev, size: sizeof(*data), GFP_KERNEL); |
71 | if (!data) |
72 | return -ENOMEM; |
73 | |
74 | data->base = devm_platform_ioremap_resource(pdev, index: 0); |
75 | if (IS_ERR(ptr: data->base)) |
76 | return PTR_ERR(ptr: data->base); |
77 | |
78 | data->rcdev.owner = THIS_MODULE; |
79 | data->rcdev.nr_resets = 1; |
80 | data->rcdev.ops = &brcm_rescal_reset_ops; |
81 | data->rcdev.of_node = pdev->dev.of_node; |
82 | data->rcdev.of_xlate = brcm_rescal_reset_xlate; |
83 | data->dev = &pdev->dev; |
84 | |
85 | return devm_reset_controller_register(dev: &pdev->dev, rcdev: &data->rcdev); |
86 | } |
87 | |
88 | static const struct of_device_id brcm_rescal_reset_of_match[] = { |
89 | { .compatible = "brcm,bcm7216-pcie-sata-rescal" }, |
90 | { }, |
91 | }; |
92 | MODULE_DEVICE_TABLE(of, brcm_rescal_reset_of_match); |
93 | |
94 | static struct platform_driver brcm_rescal_reset_driver = { |
95 | .probe = brcm_rescal_reset_probe, |
96 | .driver = { |
97 | .name = "brcm-rescal-reset" , |
98 | .of_match_table = brcm_rescal_reset_of_match, |
99 | } |
100 | }; |
101 | module_platform_driver(brcm_rescal_reset_driver); |
102 | |
103 | MODULE_AUTHOR("Broadcom" ); |
104 | MODULE_DESCRIPTION("Broadcom SATA/PCIe rescal reset controller" ); |
105 | MODULE_LICENSE("GPL v2" ); |
106 | |