1// SPDX-License-Identifier: GPL-2.0
2/**
3 * cdns3-ti.c - TI specific Glue layer for Cadence USB Controller
4 *
5 * Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com
6 */
7
8#include <linux/bits.h>
9#include <linux/clk.h>
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/interrupt.h>
13#include <linux/platform_device.h>
14#include <linux/dma-mapping.h>
15#include <linux/io.h>
16#include <linux/of_platform.h>
17#include <linux/pm_runtime.h>
18
19/* USB Wrapper register offsets */
20#define USBSS_PID		0x0
21#define	USBSS_W1		0x4
22#define USBSS_STATIC_CONFIG	0x8
23#define USBSS_PHY_TEST		0xc
24#define	USBSS_DEBUG_CTRL	0x10
25#define	USBSS_DEBUG_INFO	0x14
26#define	USBSS_DEBUG_LINK_STATE	0x18
27#define	USBSS_DEVICE_CTRL	0x1c
28
29/* Wrapper 1 register bits */
30#define USBSS_W1_PWRUP_RST		BIT(0)
31#define USBSS_W1_OVERCURRENT_SEL	BIT(8)
32#define USBSS_W1_MODESTRAP_SEL		BIT(9)
33#define USBSS_W1_OVERCURRENT		BIT(16)
34#define USBSS_W1_MODESTRAP_MASK		GENMASK(18, 17)
35#define USBSS_W1_MODESTRAP_SHIFT	17
36#define USBSS_W1_USB2_ONLY		BIT(19)
37
38/* Static config register bits */
39#define USBSS1_STATIC_PLL_REF_SEL_MASK	GENMASK(8, 5)
40#define USBSS1_STATIC_PLL_REF_SEL_SHIFT	5
41#define USBSS1_STATIC_LOOPBACK_MODE_MASK	GENMASK(4, 3)
42#define USBSS1_STATIC_LOOPBACK_MODE_SHIFT	3
43#define USBSS1_STATIC_VBUS_SEL_MASK	GENMASK(2, 1)
44#define USBSS1_STATIC_VBUS_SEL_SHIFT	1
45#define USBSS1_STATIC_LANE_REVERSE	BIT(0)
46
47/* Modestrap modes */
48enum modestrap_mode { USBSS_MODESTRAP_MODE_NONE,
49		      USBSS_MODESTRAP_MODE_HOST,
50		      USBSS_MODESTRAP_MODE_PERIPHERAL};
51
52struct cdns_ti {
53	struct device *dev;
54	void __iomem *usbss;
55	unsigned usb2_only:1;
56	unsigned vbus_divider:1;
57	struct clk *usb2_refclk;
58	struct clk *lpm_clk;
59};
60
61static const int cdns_ti_rate_table[] = {	/* in KHZ */
62	9600,
63	10000,
64	12000,
65	19200,
66	20000,
67	24000,
68	25000,
69	26000,
70	38400,
71	40000,
72	58000,
73	50000,
74	52000,
75};
76
77static inline u32 cdns_ti_readl(struct cdns_ti *data, u32 offset)
78{
79	return readl(data->usbss + offset);
80}
81
82static inline void cdns_ti_writel(struct cdns_ti *data, u32 offset, u32 value)
83{
84	writel(value, data->usbss + offset);
85}
86
87static int cdns_ti_probe(struct platform_device *pdev)
88{
89	struct device *dev = &pdev->dev;
90	struct device_node *node = pdev->dev.of_node;
91	struct cdns_ti *data;
92	int error;
93	u32 reg;
94	int rate_code, i;
95	unsigned long rate;
96
97	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
98	if (!data)
99		return -ENOMEM;
100
101	platform_set_drvdata(pdev, data);
102
103	data->dev = dev;
104
105	data->usbss = devm_platform_ioremap_resource(pdev, 0);
106	if (IS_ERR(data->usbss)) {
107		dev_err(dev, "can't map IOMEM resource\n");
108		return PTR_ERR(data->usbss);
109	}
110
111	data->usb2_refclk = devm_clk_get(dev, "ref");
112	if (IS_ERR(data->usb2_refclk)) {
113		dev_err(dev, "can't get usb2_refclk\n");
114		return PTR_ERR(data->usb2_refclk);
115	}
116
117	data->lpm_clk = devm_clk_get(dev, "lpm");
118	if (IS_ERR(data->lpm_clk)) {
119		dev_err(dev, "can't get lpm_clk\n");
120		return PTR_ERR(data->lpm_clk);
121	}
122
123	rate = clk_get_rate(data->usb2_refclk);
124	rate /= 1000;	/* To KHz */
125	for (i = 0; i < ARRAY_SIZE(cdns_ti_rate_table); i++) {
126		if (cdns_ti_rate_table[i] == rate)
127			break;
128	}
129
130	if (i == ARRAY_SIZE(cdns_ti_rate_table)) {
131		dev_err(dev, "unsupported usb2_refclk rate: %lu KHz\n", rate);
132		return -EINVAL;
133	}
134
135	rate_code = i;
136
137	pm_runtime_enable(dev);
138	error = pm_runtime_get_sync(dev);
139	if (error < 0) {
140		dev_err(dev, "pm_runtime_get_sync failed: %d\n", error);
141		goto err;
142	}
143
144	/* assert RESET */
145	reg = cdns_ti_readl(data, USBSS_W1);
146	reg &= ~USBSS_W1_PWRUP_RST;
147	cdns_ti_writel(data, USBSS_W1, reg);
148
149	/* set static config */
150	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
151	reg &= ~USBSS1_STATIC_PLL_REF_SEL_MASK;
152	reg |= rate_code << USBSS1_STATIC_PLL_REF_SEL_SHIFT;
153
154	reg &= ~USBSS1_STATIC_VBUS_SEL_MASK;
155	data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
156	if (data->vbus_divider)
157		reg |= 1 << USBSS1_STATIC_VBUS_SEL_SHIFT;
158
159	cdns_ti_writel(data, USBSS_STATIC_CONFIG, reg);
160	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
161
162	/* set USB2_ONLY mode if requested */
163	reg = cdns_ti_readl(data, USBSS_W1);
164	data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
165	if (data->usb2_only)
166		reg |= USBSS_W1_USB2_ONLY;
167
168	/* set default modestrap */
169	reg |= USBSS_W1_MODESTRAP_SEL;
170	reg &= ~USBSS_W1_MODESTRAP_MASK;
171	reg |= USBSS_MODESTRAP_MODE_NONE << USBSS_W1_MODESTRAP_SHIFT;
172	cdns_ti_writel(data, USBSS_W1, reg);
173
174	/* de-assert RESET */
175	reg |= USBSS_W1_PWRUP_RST;
176	cdns_ti_writel(data, USBSS_W1, reg);
177
178	error = of_platform_populate(node, NULL, NULL, dev);
179	if (error) {
180		dev_err(dev, "failed to create children: %d\n", error);
181		goto err;
182	}
183
184	return 0;
185
186err:
187	pm_runtime_put_sync(data->dev);
188	pm_runtime_disable(data->dev);
189
190	return error;
191}
192
193static int cdns_ti_remove_core(struct device *dev, void *c)
194{
195	struct platform_device *pdev = to_platform_device(dev);
196
197	platform_device_unregister(pdev);
198
199	return 0;
200}
201
202static int cdns_ti_remove(struct platform_device *pdev)
203{
204	struct device *dev = &pdev->dev;
205
206	device_for_each_child(dev, NULL, cdns_ti_remove_core);
207	pm_runtime_put_sync(dev);
208	pm_runtime_disable(dev);
209
210	platform_set_drvdata(pdev, NULL);
211
212	return 0;
213}
214
215static const struct of_device_id cdns_ti_of_match[] = {
216	{ .compatible = "ti,j721e-usb", },
217	{},
218};
219MODULE_DEVICE_TABLE(of, cdns_ti_of_match);
220
221static struct platform_driver cdns_ti_driver = {
222	.probe		= cdns_ti_probe,
223	.remove		= cdns_ti_remove,
224	.driver		= {
225		.name	= "cdns3-ti",
226		.of_match_table	= cdns_ti_of_match,
227	},
228};
229
230module_platform_driver(cdns_ti_driver);
231
232MODULE_ALIAS("platform:cdns3-ti");
233MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
234MODULE_LICENSE("GPL v2");
235MODULE_DESCRIPTION("Cadence USB3 TI Glue Layer");
236