1 // SPDX-License-Identifier: GPL-2.0
2 /**
3  * cdns3-starfive.c - StarFive specific Glue layer for Cadence USB Controller
4  *
5  * Copyright (C) 2023 StarFive Technology Co., Ltd.
6  *
7  * Author:	Minda Chen <minda.chen@starfivetech.com>
8  */
9 
10 #include <linux/bits.h>
11 #include <linux/clk.h>
12 #include <linux/module.h>
13 #include <linux/mfd/syscon.h>
14 #include <linux/kernel.h>
15 #include <linux/platform_device.h>
16 #include <linux/io.h>
17 #include <linux/of_platform.h>
18 #include <linux/reset.h>
19 #include <linux/regmap.h>
20 #include <linux/usb/otg.h>
21 #include "core.h"
22 
23 #define USB_STRAP_HOST			BIT(17)
24 #define USB_STRAP_DEVICE		BIT(18)
25 #define USB_STRAP_MASK			GENMASK(18, 16)
26 
27 #define USB_SUSPENDM_HOST		BIT(19)
28 #define USB_SUSPENDM_MASK		BIT(19)
29 
30 #define USB_MISC_CFG_MASK		GENMASK(23, 20)
31 #define USB_SUSPENDM_BYPS		BIT(20)
32 #define USB_PLL_EN			BIT(22)
33 #define USB_REFCLK_MODE			BIT(23)
34 
35 struct cdns_starfive {
36 	struct device *dev;
37 	struct regmap *stg_syscon;
38 	struct reset_control *resets;
39 	struct clk_bulk_data *clks;
40 	int num_clks;
41 	u32 stg_usb_mode;
42 };
43 
44 static void cdns_mode_init(struct platform_device *pdev,
45 			   struct cdns_starfive *data)
46 {
47 	enum usb_dr_mode mode;
48 
49 	regmap_update_bits(data->stg_syscon, data->stg_usb_mode,
50 			   USB_MISC_CFG_MASK,
51 			   USB_SUSPENDM_BYPS | USB_PLL_EN | USB_REFCLK_MODE);
52 
53 	/* dr mode setting */
54 	mode = usb_get_dr_mode(&pdev->dev);
55 
56 	switch (mode) {
57 	case USB_DR_MODE_HOST:
58 		regmap_update_bits(data->stg_syscon,
59 				   data->stg_usb_mode,
60 				   USB_STRAP_MASK,
61 				   USB_STRAP_HOST);
62 		regmap_update_bits(data->stg_syscon,
63 				   data->stg_usb_mode,
64 				   USB_SUSPENDM_MASK,
65 				   USB_SUSPENDM_HOST);
66 		break;
67 
68 	case USB_DR_MODE_PERIPHERAL:
69 		regmap_update_bits(data->stg_syscon, data->stg_usb_mode,
70 				   USB_STRAP_MASK, USB_STRAP_DEVICE);
71 		regmap_update_bits(data->stg_syscon, data->stg_usb_mode,
72 				   USB_SUSPENDM_MASK, 0);
73 		break;
74 	default:
75 		break;
76 	}
77 }
78 
79 static int cdns_clk_rst_init(struct cdns_starfive *data)
80 {
81 	int ret;
82 
83 	ret = clk_bulk_prepare_enable(data->num_clks, data->clks);
84 	if (ret)
85 		return dev_err_probe(data->dev, ret,
86 				     "failed to enable clocks\n");
87 
88 	ret = reset_control_deassert(data->resets);
89 	if (ret) {
90 		dev_err(data->dev, "failed to reset clocks\n");
91 		goto err_clk_init;
92 	}
93 
94 	return ret;
95 
96 err_clk_init:
97 	clk_bulk_disable_unprepare(data->num_clks, data->clks);
98 	return ret;
99 }
100 
101 static void cdns_clk_rst_deinit(struct cdns_starfive *data)
102 {
103 	reset_control_assert(data->resets);
104 	clk_bulk_disable_unprepare(data->num_clks, data->clks);
105 }
106 
107 static int cdns_starfive_probe(struct platform_device *pdev)
108 {
109 	struct device *dev = &pdev->dev;
110 	struct cdns_starfive *data;
111 	unsigned int args;
112 	int ret;
113 
114 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
115 	if (!data)
116 		return -ENOMEM;
117 
118 	data->dev = dev;
119 
120 	data->stg_syscon =
121 		syscon_regmap_lookup_by_phandle_args(pdev->dev.of_node,
122 						     "starfive,stg-syscon", 1, &args);
123 
124 	if (IS_ERR(data->stg_syscon))
125 		return dev_err_probe(dev, PTR_ERR(data->stg_syscon),
126 				     "Failed to parse starfive,stg-syscon\n");
127 
128 	data->stg_usb_mode = args;
129 
130 	data->num_clks = devm_clk_bulk_get_all(data->dev, &data->clks);
131 	if (data->num_clks < 0)
132 		return dev_err_probe(data->dev, -ENODEV,
133 				     "Failed to get clocks\n");
134 
135 	data->resets = devm_reset_control_array_get_exclusive(data->dev);
136 	if (IS_ERR(data->resets))
137 		return dev_err_probe(data->dev, PTR_ERR(data->resets),
138 				     "Failed to get resets");
139 
140 	cdns_mode_init(pdev, data);
141 	ret = cdns_clk_rst_init(data);
142 	if (ret)
143 		return ret;
144 
145 	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
146 	if (ret) {
147 		dev_err(dev, "Failed to create children\n");
148 		cdns_clk_rst_deinit(data);
149 		return ret;
150 	}
151 
152 	device_set_wakeup_capable(dev, true);
153 	pm_runtime_set_active(dev);
154 	pm_runtime_enable(dev);
155 	platform_set_drvdata(pdev, data);
156 
157 	return 0;
158 }
159 
160 static int cdns_starfive_remove_core(struct device *dev, void *c)
161 {
162 	struct platform_device *pdev = to_platform_device(dev);
163 
164 	platform_device_unregister(pdev);
165 
166 	return 0;
167 }
168 
169 static int cdns_starfive_remove(struct platform_device *pdev)
170 {
171 	struct device *dev = &pdev->dev;
172 	struct cdns_starfive *data = dev_get_drvdata(dev);
173 
174 	pm_runtime_get_sync(dev);
175 	device_for_each_child(dev, NULL, cdns_starfive_remove_core);
176 
177 	pm_runtime_disable(dev);
178 	pm_runtime_put_noidle(dev);
179 	cdns_clk_rst_deinit(data);
180 	platform_set_drvdata(pdev, NULL);
181 
182 	return 0;
183 }
184 
185 #ifdef CONFIG_PM
186 static int cdns_starfive_runtime_resume(struct device *dev)
187 {
188 	struct cdns_starfive *data = dev_get_drvdata(dev);
189 
190 	return clk_bulk_prepare_enable(data->num_clks, data->clks);
191 }
192 
193 static int cdns_starfive_runtime_suspend(struct device *dev)
194 {
195 	struct cdns_starfive *data = dev_get_drvdata(dev);
196 
197 	clk_bulk_disable_unprepare(data->num_clks, data->clks);
198 
199 	return 0;
200 }
201 
202 #ifdef CONFIG_PM_SLEEP
203 static int cdns_starfive_resume(struct device *dev)
204 {
205 	struct cdns_starfive *data = dev_get_drvdata(dev);
206 
207 	return cdns_clk_rst_init(data);
208 }
209 
210 static int cdns_starfive_suspend(struct device *dev)
211 {
212 	struct cdns_starfive *data = dev_get_drvdata(dev);
213 
214 	cdns_clk_rst_deinit(data);
215 
216 	return 0;
217 }
218 #endif
219 #endif
220 
221 static const struct dev_pm_ops cdns_starfive_pm_ops = {
222 	SET_RUNTIME_PM_OPS(cdns_starfive_runtime_suspend,
223 			   cdns_starfive_runtime_resume, NULL)
224 	SET_SYSTEM_SLEEP_PM_OPS(cdns_starfive_suspend, cdns_starfive_resume)
225 };
226 
227 static const struct of_device_id cdns_starfive_of_match[] = {
228 	{ .compatible = "starfive,jh7110-usb", },
229 	{ /* sentinel */ }
230 };
231 MODULE_DEVICE_TABLE(of, cdns_starfive_of_match);
232 
233 static struct platform_driver cdns_starfive_driver = {
234 	.probe		= cdns_starfive_probe,
235 	.remove		= cdns_starfive_remove,
236 	.driver		= {
237 		.name	= "cdns3-starfive",
238 		.of_match_table	= cdns_starfive_of_match,
239 		.pm	= &cdns_starfive_pm_ops,
240 	},
241 };
242 module_platform_driver(cdns_starfive_driver);
243 
244 MODULE_ALIAS("platform:cdns3-starfive");
245 MODULE_LICENSE("GPL v2");
246 MODULE_DESCRIPTION("Cadence USB3 StarFive Glue Layer");
247