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#include <linux/property.h>
19
20/* USB Wrapper register offsets */
21#define USBSS_PID		0x0
22#define	USBSS_W1		0x4
23#define USBSS_STATIC_CONFIG	0x8
24#define USBSS_PHY_TEST		0xc
25#define	USBSS_DEBUG_CTRL	0x10
26#define	USBSS_DEBUG_INFO	0x14
27#define	USBSS_DEBUG_LINK_STATE	0x18
28#define	USBSS_DEVICE_CTRL	0x1c
29
30/* Wrapper 1 register bits */
31#define USBSS_W1_PWRUP_RST		BIT(0)
32#define USBSS_W1_OVERCURRENT_SEL	BIT(8)
33#define USBSS_W1_MODESTRAP_SEL		BIT(9)
34#define USBSS_W1_OVERCURRENT		BIT(16)
35#define USBSS_W1_MODESTRAP_MASK		GENMASK(18, 17)
36#define USBSS_W1_MODESTRAP_SHIFT	17
37#define USBSS_W1_USB2_ONLY		BIT(19)
38
39/* Static config register bits */
40#define USBSS1_STATIC_PLL_REF_SEL_MASK	GENMASK(8, 5)
41#define USBSS1_STATIC_PLL_REF_SEL_SHIFT	5
42#define USBSS1_STATIC_LOOPBACK_MODE_MASK	GENMASK(4, 3)
43#define USBSS1_STATIC_LOOPBACK_MODE_SHIFT	3
44#define USBSS1_STATIC_VBUS_SEL_MASK	GENMASK(2, 1)
45#define USBSS1_STATIC_VBUS_SEL_SHIFT	1
46#define USBSS1_STATIC_LANE_REVERSE	BIT(0)
47
48/* Modestrap modes */
49enum modestrap_mode { USBSS_MODESTRAP_MODE_NONE,
50		      USBSS_MODESTRAP_MODE_HOST,
51		      USBSS_MODESTRAP_MODE_PERIPHERAL};
52
53struct cdns_ti {
54	struct device *dev;
55	void __iomem *usbss;
56	unsigned usb2_only:1;
57	unsigned vbus_divider:1;
58	struct clk *usb2_refclk;
59	struct clk *lpm_clk;
60};
61
62static const int cdns_ti_rate_table[] = {	/* in KHZ */
63	9600,
64	10000,
65	12000,
66	19200,
67	20000,
68	24000,
69	25000,
70	26000,
71	38400,
72	40000,
73	58000,
74	50000,
75	52000,
76};
77
78static inline u32 cdns_ti_readl(struct cdns_ti *data, u32 offset)
79{
80	return readl(data->usbss + offset);
81}
82
83static inline void cdns_ti_writel(struct cdns_ti *data, u32 offset, u32 value)
84{
85	writel(value, data->usbss + offset);
86}
87
88static int cdns_ti_probe(struct platform_device *pdev)
89{
90	struct device *dev = &pdev->dev;
91	struct device_node *node = pdev->dev.of_node;
92	struct cdns_ti *data;
93	int error;
94	u32 reg;
95	int rate_code, i;
96	unsigned long rate;
97
98	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
99	if (!data)
100		return -ENOMEM;
101
102	platform_set_drvdata(pdev, data);
103
104	data->dev = dev;
105
106	data->usbss = devm_platform_ioremap_resource(pdev, 0);
107	if (IS_ERR(data->usbss)) {
108		dev_err(dev, "can't map IOMEM resource\n");
109		return PTR_ERR(data->usbss);
110	}
111
112	data->usb2_refclk = devm_clk_get(dev, "ref");
113	if (IS_ERR(data->usb2_refclk)) {
114		dev_err(dev, "can't get usb2_refclk\n");
115		return PTR_ERR(data->usb2_refclk);
116	}
117
118	data->lpm_clk = devm_clk_get(dev, "lpm");
119	if (IS_ERR(data->lpm_clk)) {
120		dev_err(dev, "can't get lpm_clk\n");
121		return PTR_ERR(data->lpm_clk);
122	}
123
124	rate = clk_get_rate(data->usb2_refclk);
125	rate /= 1000;	/* To KHz */
126	for (i = 0; i < ARRAY_SIZE(cdns_ti_rate_table); i++) {
127		if (cdns_ti_rate_table[i] == rate)
128			break;
129	}
130
131	if (i == ARRAY_SIZE(cdns_ti_rate_table)) {
132		dev_err(dev, "unsupported usb2_refclk rate: %lu KHz\n", rate);
133		return -EINVAL;
134	}
135
136	rate_code = i;
137
138	pm_runtime_enable(dev);
139	error = pm_runtime_get_sync(dev);
140	if (error < 0) {
141		dev_err(dev, "pm_runtime_get_sync failed: %d\n", error);
142		goto err;
143	}
144
145	/* assert RESET */
146	reg = cdns_ti_readl(data, USBSS_W1);
147	reg &= ~USBSS_W1_PWRUP_RST;
148	cdns_ti_writel(data, USBSS_W1, reg);
149
150	/* set static config */
151	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
152	reg &= ~USBSS1_STATIC_PLL_REF_SEL_MASK;
153	reg |= rate_code << USBSS1_STATIC_PLL_REF_SEL_SHIFT;
154
155	reg &= ~USBSS1_STATIC_VBUS_SEL_MASK;
156	data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
157	if (data->vbus_divider)
158		reg |= 1 << USBSS1_STATIC_VBUS_SEL_SHIFT;
159
160	cdns_ti_writel(data, USBSS_STATIC_CONFIG, reg);
161	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
162
163	/* set USB2_ONLY mode if requested */
164	reg = cdns_ti_readl(data, USBSS_W1);
165	data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
166	if (data->usb2_only)
167		reg |= USBSS_W1_USB2_ONLY;
168
169	/* set default modestrap */
170	reg |= USBSS_W1_MODESTRAP_SEL;
171	reg &= ~USBSS_W1_MODESTRAP_MASK;
172	reg |= USBSS_MODESTRAP_MODE_NONE << USBSS_W1_MODESTRAP_SHIFT;
173	cdns_ti_writel(data, USBSS_W1, reg);
174
175	/* de-assert RESET */
176	reg |= USBSS_W1_PWRUP_RST;
177	cdns_ti_writel(data, USBSS_W1, reg);
178
179	error = of_platform_populate(node, NULL, NULL, dev);
180	if (error) {
181		dev_err(dev, "failed to create children: %d\n", error);
182		goto err;
183	}
184
185	return 0;
186
187err:
188	pm_runtime_put_sync(data->dev);
189	pm_runtime_disable(data->dev);
190
191	return error;
192}
193
194static int cdns_ti_remove_core(struct device *dev, void *c)
195{
196	struct platform_device *pdev = to_platform_device(dev);
197
198	platform_device_unregister(pdev);
199
200	return 0;
201}
202
203static void cdns_ti_remove(struct platform_device *pdev)
204{
205	struct device *dev = &pdev->dev;
206
207	device_for_each_child(dev, NULL, cdns_ti_remove_core);
208	pm_runtime_put_sync(dev);
209	pm_runtime_disable(dev);
210
211	platform_set_drvdata(pdev, NULL);
212}
213
214static const struct of_device_id cdns_ti_of_match[] = {
215	{ .compatible = "ti,j721e-usb", },
216	{ .compatible = "ti,am64-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_new	= 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