cdns3-ti.c

  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	int usb2_refclk_rate_code;
 62};
 63
 64static const int cdns_ti_rate_table[] = {	/* in KHZ */
 65	9600,
 66	10000,
 67	12000,
 68	19200,
 69	20000,
 70	24000,
 71	25000,
 72	26000,
 73	38400,
 74	40000,
 75	58000,
 76	50000,
 77	52000,
 78};
 79
 80static inline u32 cdns_ti_readl(struct cdns_ti *data, u32 offset)
 81{
 82	return readl(data->usbss + offset);
 83}
 84
 85static inline void cdns_ti_writel(struct cdns_ti *data, u32 offset, u32 value)
 86{
 87	writel(value, data->usbss + offset);
 88}
 89
 90static struct cdns3_platform_data cdns_ti_pdata = {
 91	.quirks = CDNS3_DRD_SUSPEND_RESIDENCY_ENABLE,   /* Errata i2409 */
 92};
 93
 94static const struct of_dev_auxdata cdns_ti_auxdata[] = {
 95	{
 96		.compatible = "cdns,usb3",
 97		.platform_data = &cdns_ti_pdata,
 98	},
 99	{},
100};
101
102static void cdns_ti_reset_and_init_hw(struct cdns_ti *data)
103{
104	u32 reg;
105
106	/* assert RESET */
107	reg = cdns_ti_readl(data, USBSS_W1);
108	reg &= ~USBSS_W1_PWRUP_RST;
109	cdns_ti_writel(data, USBSS_W1, reg);
110
111	/* set static config */
112	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
113	reg &= ~USBSS1_STATIC_PLL_REF_SEL_MASK;
114	reg |= data->usb2_refclk_rate_code << USBSS1_STATIC_PLL_REF_SEL_SHIFT;
115
116	reg &= ~USBSS1_STATIC_VBUS_SEL_MASK;
117	if (data->vbus_divider)
118		reg |= 1 << USBSS1_STATIC_VBUS_SEL_SHIFT;
119
120	cdns_ti_writel(data, USBSS_STATIC_CONFIG, reg);
121	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
122
123	/* set USB2_ONLY mode if requested */
124	reg = cdns_ti_readl(data, USBSS_W1);
125	if (data->usb2_only)
126		reg |= USBSS_W1_USB2_ONLY;
127
128	/* set default modestrap */
129	reg |= USBSS_W1_MODESTRAP_SEL;
130	reg &= ~USBSS_W1_MODESTRAP_MASK;
131	reg |= USBSS_MODESTRAP_MODE_NONE << USBSS_W1_MODESTRAP_SHIFT;
132	cdns_ti_writel(data, USBSS_W1, reg);
133
134	/* de-assert RESET */
135	reg |= USBSS_W1_PWRUP_RST;
136	cdns_ti_writel(data, USBSS_W1, reg);
137}
138
139static int cdns_ti_probe(struct platform_device *pdev)
140{
141	struct device *dev = &pdev->dev;
142	struct device_node *node = pdev->dev.of_node;
143	struct cdns_ti *data;
144	unsigned long rate;
145	int error, i;
146
147	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
148	if (!data)
149		return -ENOMEM;
150
151	platform_set_drvdata(pdev, data);
152
153	data->dev = dev;
154
155	data->usbss = devm_platform_ioremap_resource(pdev, 0);
156	if (IS_ERR(data->usbss)) {
157		dev_err(dev, "can't map IOMEM resource\n");
158		return PTR_ERR(data->usbss);
159	}
160
161	data->usb2_refclk = devm_clk_get(dev, "ref");
162	if (IS_ERR(data->usb2_refclk)) {
163		dev_err(dev, "can't get usb2_refclk\n");
164		return PTR_ERR(data->usb2_refclk);
165	}
166
167	data->lpm_clk = devm_clk_get(dev, "lpm");
168	if (IS_ERR(data->lpm_clk)) {
169		dev_err(dev, "can't get lpm_clk\n");
170		return PTR_ERR(data->lpm_clk);
171	}
172
173	rate = clk_get_rate(data->usb2_refclk);
174	rate /= 1000;	/* To KHz */
175	for (i = 0; i < ARRAY_SIZE(cdns_ti_rate_table); i++) {
176		if (cdns_ti_rate_table[i] == rate)
177			break;
178	}
179
180	if (i == ARRAY_SIZE(cdns_ti_rate_table)) {
181		dev_err(dev, "unsupported usb2_refclk rate: %lu KHz\n", rate);
182		return -EINVAL;
183	}
184
185	data->usb2_refclk_rate_code = i;
186	data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
187	data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
188
189	/*
190	 * The call below to pm_runtime_get_sync() MIGHT reset hardware, if it
191	 * detects it as uninitialised. We want to enforce a reset at probe,
192	 * and so do it manually here. This means the first runtime_resume()
193	 * will be a no-op.
194	 */
195	cdns_ti_reset_and_init_hw(data);
196
197	pm_runtime_enable(dev);
198	error = pm_runtime_get_sync(dev);
199	if (error < 0) {
200		dev_err(dev, "pm_runtime_get_sync failed: %d\n", error);
201		goto err;
202	}
203
204	error = of_platform_populate(node, NULL, cdns_ti_auxdata, dev);
205	if (error) {
206		dev_err(dev, "failed to create children: %d\n", error);
207		goto err;
208	}
209
210	return 0;
211
212err:
213	pm_runtime_put_sync(data->dev);
214	pm_runtime_disable(data->dev);
215
216	return error;
217}
218
219static int cdns_ti_remove_core(struct device *dev, void *c)
220{
221	struct platform_device *pdev = to_platform_device(dev);
222
223	platform_device_unregister(pdev);
224
225	return 0;
226}
227
228static void cdns_ti_remove(struct platform_device *pdev)
229{
230	struct device *dev = &pdev->dev;
231
232	device_for_each_child(dev, NULL, cdns_ti_remove_core);
233	pm_runtime_put_sync(dev);
234	pm_runtime_disable(dev);
235
236	platform_set_drvdata(pdev, NULL);
237}
238
239static int cdns_ti_runtime_resume(struct device *dev)
240{
241	const u32 mask = USBSS_W1_PWRUP_RST | USBSS_W1_MODESTRAP_SEL;
242	struct cdns_ti *data = dev_get_drvdata(dev);
243	u32 w1;
244
245	w1 = cdns_ti_readl(data, USBSS_W1);
246	if ((w1 & mask) != mask)
247		cdns_ti_reset_and_init_hw(data);
248
249	return 0;
250}
251
252static const struct dev_pm_ops cdns_ti_pm_ops = {
253	RUNTIME_PM_OPS(NULL, cdns_ti_runtime_resume, NULL)
254	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
255};
256
257static const struct of_device_id cdns_ti_of_match[] = {
258	{ .compatible = "ti,j721e-usb", },
259	{ .compatible = "ti,am64-usb", },
260	{},
261};
262MODULE_DEVICE_TABLE(of, cdns_ti_of_match);
263
264static struct platform_driver cdns_ti_driver = {
265	.probe		= cdns_ti_probe,
266	.remove		= cdns_ti_remove,
267	.driver		= {
268		.name	= "cdns3-ti",
269		.of_match_table	= cdns_ti_of_match,
270		.pm     = pm_ptr(&cdns_ti_pm_ops),
271	},
272};
273
274module_platform_driver(cdns_ti_driver);
275
276MODULE_ALIAS("platform:cdns3-ti");
277MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
278MODULE_LICENSE("GPL v2");
279MODULE_DESCRIPTION("Cadence USB3 TI Glue Layer");