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#include "core.h"
 20
 21/* USB Wrapper register offsets */
 22#define USBSS_PID		0x0
 23#define	USBSS_W1		0x4
 24#define USBSS_STATIC_CONFIG	0x8
 25#define USBSS_PHY_TEST		0xc
 26#define	USBSS_DEBUG_CTRL	0x10
 27#define	USBSS_DEBUG_INFO	0x14
 28#define	USBSS_DEBUG_LINK_STATE	0x18
 29#define	USBSS_DEVICE_CTRL	0x1c
 30
 31/* Wrapper 1 register bits */
 32#define USBSS_W1_PWRUP_RST		BIT(0)
 33#define USBSS_W1_OVERCURRENT_SEL	BIT(8)
 34#define USBSS_W1_MODESTRAP_SEL		BIT(9)
 35#define USBSS_W1_OVERCURRENT		BIT(16)
 36#define USBSS_W1_MODESTRAP_MASK		GENMASK(18, 17)
 37#define USBSS_W1_MODESTRAP_SHIFT	17
 38#define USBSS_W1_USB2_ONLY		BIT(19)
 39
 40/* Static config register bits */
 41#define USBSS1_STATIC_PLL_REF_SEL_MASK	GENMASK(8, 5)
 42#define USBSS1_STATIC_PLL_REF_SEL_SHIFT	5
 43#define USBSS1_STATIC_LOOPBACK_MODE_MASK	GENMASK(4, 3)
 44#define USBSS1_STATIC_LOOPBACK_MODE_SHIFT	3
 45#define USBSS1_STATIC_VBUS_SEL_MASK	GENMASK(2, 1)
 46#define USBSS1_STATIC_VBUS_SEL_SHIFT	1
 47#define USBSS1_STATIC_LANE_REVERSE	BIT(0)
 48
 49/* Modestrap modes */
 50enum modestrap_mode { USBSS_MODESTRAP_MODE_NONE,
 51		      USBSS_MODESTRAP_MODE_HOST,
 52		      USBSS_MODESTRAP_MODE_PERIPHERAL};
 53
 54struct cdns_ti {
 55	struct device *dev;
 56	void __iomem *usbss;
 57	unsigned usb2_only:1;
 58	unsigned vbus_divider:1;
 59	struct clk *usb2_refclk;
 60	struct clk *lpm_clk;
 61};
 62
 63static const int cdns_ti_rate_table[] = {	/* in KHZ */
 64	9600,
 65	10000,
 66	12000,
 67	19200,
 68	20000,
 69	24000,
 70	25000,
 71	26000,
 72	38400,
 73	40000,
 74	58000,
 75	50000,
 76	52000,
 77};
 78
 79static inline u32 cdns_ti_readl(struct cdns_ti *data, u32 offset)
 80{
 81	return readl(data->usbss + offset);
 82}
 83
 84static inline void cdns_ti_writel(struct cdns_ti *data, u32 offset, u32 value)
 85{
 86	writel(value, data->usbss + offset);
 87}
 88
 89static struct cdns3_platform_data cdns_ti_pdata = {
 90	.quirks = CDNS3_DRD_SUSPEND_RESIDENCY_ENABLE,   /* Errata i2409 */
 91};
 92
 93static const struct of_dev_auxdata cdns_ti_auxdata[] = {
 94	{
 95		.compatible = "cdns,usb3",
 96		.platform_data = &cdns_ti_pdata,
 97	},
 98	{},
 99};
100
101static int cdns_ti_probe(struct platform_device *pdev)
102{
103	struct device *dev = &pdev->dev;
104	struct device_node *node = pdev->dev.of_node;
105	struct cdns_ti *data;
106	int error;
107	u32 reg;
108	int rate_code, i;
109	unsigned long rate;
110
111	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
112	if (!data)
113		return -ENOMEM;
114
115	platform_set_drvdata(pdev, data);
116
117	data->dev = dev;
118
119	data->usbss = devm_platform_ioremap_resource(pdev, 0);
120	if (IS_ERR(data->usbss)) {
121		dev_err(dev, "can't map IOMEM resource\n");
122		return PTR_ERR(data->usbss);
123	}
124
125	data->usb2_refclk = devm_clk_get(dev, "ref");
126	if (IS_ERR(data->usb2_refclk)) {
127		dev_err(dev, "can't get usb2_refclk\n");
128		return PTR_ERR(data->usb2_refclk);
129	}
130
131	data->lpm_clk = devm_clk_get(dev, "lpm");
132	if (IS_ERR(data->lpm_clk)) {
133		dev_err(dev, "can't get lpm_clk\n");
134		return PTR_ERR(data->lpm_clk);
135	}
136
137	rate = clk_get_rate(data->usb2_refclk);
138	rate /= 1000;	/* To KHz */
139	for (i = 0; i < ARRAY_SIZE(cdns_ti_rate_table); i++) {
140		if (cdns_ti_rate_table[i] == rate)
141			break;
142	}
143
144	if (i == ARRAY_SIZE(cdns_ti_rate_table)) {
145		dev_err(dev, "unsupported usb2_refclk rate: %lu KHz\n", rate);
146		return -EINVAL;
147	}
148
149	rate_code = i;
150
151	pm_runtime_enable(dev);
152	error = pm_runtime_get_sync(dev);
153	if (error < 0) {
154		dev_err(dev, "pm_runtime_get_sync failed: %d\n", error);
155		goto err;
156	}
157
158	/* assert RESET */
159	reg = cdns_ti_readl(data, USBSS_W1);
160	reg &= ~USBSS_W1_PWRUP_RST;
161	cdns_ti_writel(data, USBSS_W1, reg);
162
163	/* set static config */
164	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
165	reg &= ~USBSS1_STATIC_PLL_REF_SEL_MASK;
166	reg |= rate_code << USBSS1_STATIC_PLL_REF_SEL_SHIFT;
167
168	reg &= ~USBSS1_STATIC_VBUS_SEL_MASK;
169	data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
170	if (data->vbus_divider)
171		reg |= 1 << USBSS1_STATIC_VBUS_SEL_SHIFT;
172
173	cdns_ti_writel(data, USBSS_STATIC_CONFIG, reg);
174	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
175
176	/* set USB2_ONLY mode if requested */
177	reg = cdns_ti_readl(data, USBSS_W1);
178	data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
179	if (data->usb2_only)
180		reg |= USBSS_W1_USB2_ONLY;
181
182	/* set default modestrap */
183	reg |= USBSS_W1_MODESTRAP_SEL;
184	reg &= ~USBSS_W1_MODESTRAP_MASK;
185	reg |= USBSS_MODESTRAP_MODE_NONE << USBSS_W1_MODESTRAP_SHIFT;
186	cdns_ti_writel(data, USBSS_W1, reg);
187
188	/* de-assert RESET */
189	reg |= USBSS_W1_PWRUP_RST;
190	cdns_ti_writel(data, USBSS_W1, reg);
191
192	error = of_platform_populate(node, NULL, cdns_ti_auxdata, dev);
193	if (error) {
194		dev_err(dev, "failed to create children: %d\n", error);
195		goto err;
196	}
197
198	return 0;
199
200err:
201	pm_runtime_put_sync(data->dev);
202	pm_runtime_disable(data->dev);
203
204	return error;
205}
206
207static int cdns_ti_remove_core(struct device *dev, void *c)
208{
209	struct platform_device *pdev = to_platform_device(dev);
210
211	platform_device_unregister(pdev);
212
213	return 0;
214}
215
216static void cdns_ti_remove(struct platform_device *pdev)
217{
218	struct device *dev = &pdev->dev;
219
220	device_for_each_child(dev, NULL, cdns_ti_remove_core);
221	pm_runtime_put_sync(dev);
222	pm_runtime_disable(dev);
223
224	platform_set_drvdata(pdev, NULL);
225}
226
227static const struct of_device_id cdns_ti_of_match[] = {
228	{ .compatible = "ti,j721e-usb", },
229	{ .compatible = "ti,am64-usb", },
230	{},
231};
232MODULE_DEVICE_TABLE(of, cdns_ti_of_match);
233
234static struct platform_driver cdns_ti_driver = {
235	.probe		= cdns_ti_probe,
236	.remove		= cdns_ti_remove,
237	.driver		= {
238		.name	= "cdns3-ti",
239		.of_match_table	= cdns_ti_of_match,
240	},
241};
242
243module_platform_driver(cdns_ti_driver);
244
245MODULE_ALIAS("platform:cdns3-ti");
246MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
247MODULE_LICENSE("GPL v2");
248MODULE_DESCRIPTION("Cadence USB3 TI Glue Layer");