1/*
  2 * omap-usb2.c - USB PHY, talking to musb controller in OMAP.
  3 *
  4 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
  5 * This program is free software; you can redistribute it and/or modify
  6 * it under the terms of the GNU General Public License as published by
  7 * the Free Software Foundation; either version 2 of the License, or
  8 * (at your option) any later version.
  9 *
 10 * Author: Kishon Vijay Abraham I <kishon@ti.com>
 11 *
 12 * This program is distributed in the hope that it will be useful,
 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15 * GNU General Public License for more details.
 16 *
 17 */
 18
 19#include <linux/module.h>
 20#include <linux/platform_device.h>
 21#include <linux/slab.h>
 22#include <linux/of.h>
 23#include <linux/io.h>
 24#include <linux/phy/omap_usb.h>
 25#include <linux/usb/phy_companion.h>
 26#include <linux/clk.h>
 27#include <linux/err.h>
 28#include <linux/pm_runtime.h>
 29#include <linux/delay.h>
 30#include <linux/phy/omap_control_phy.h>
 31#include <linux/phy/phy.h>
 32#include <linux/mfd/syscon.h>
 33#include <linux/regmap.h>
 34#include <linux/of_platform.h>
 35
 36#define USB2PHY_DISCON_BYP_LATCH (1 << 31)
 37#define USB2PHY_ANA_CONFIG1 0x4c
 38
 39/**
 40 * omap_usb2_set_comparator - links the comparator present in the sytem with
 41 *	this phy
 42 * @comparator - the companion phy(comparator) for this phy
 43 *
 44 * The phy companion driver should call this API passing the phy_companion
 45 * filled with set_vbus and start_srp to be used by usb phy.
 46 *
 47 * For use by phy companion driver
 48 */
 49int omap_usb2_set_comparator(struct phy_companion *comparator)
 50{
 51	struct omap_usb	*phy;
 52	struct usb_phy	*x = usb_get_phy(USB_PHY_TYPE_USB2);
 53
 54	if (IS_ERR(x))
 55		return -ENODEV;
 56
 57	phy = phy_to_omapusb(x);
 58	phy->comparator = comparator;
 59	return 0;
 60}
 61EXPORT_SYMBOL_GPL(omap_usb2_set_comparator);
 62
 63static int omap_usb_set_vbus(struct usb_otg *otg, bool enabled)
 64{
 65	struct omap_usb *phy = phy_to_omapusb(otg->usb_phy);
 66
 67	if (!phy->comparator)
 68		return -ENODEV;
 69
 70	return phy->comparator->set_vbus(phy->comparator, enabled);
 71}
 72
 73static int omap_usb_start_srp(struct usb_otg *otg)
 74{
 75	struct omap_usb *phy = phy_to_omapusb(otg->usb_phy);
 76
 77	if (!phy->comparator)
 78		return -ENODEV;
 79
 80	return phy->comparator->start_srp(phy->comparator);
 81}
 82
 83static int omap_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
 84{
 85	otg->host = host;
 86	if (!host)
 87		otg->state = OTG_STATE_UNDEFINED;
 88
 89	return 0;
 90}
 91
 92static int omap_usb_set_peripheral(struct usb_otg *otg,
 93		struct usb_gadget *gadget)
 94{
 95	otg->gadget = gadget;
 96	if (!gadget)
 97		otg->state = OTG_STATE_UNDEFINED;
 98
 99	return 0;
100}
101
102static int omap_usb_phy_power(struct omap_usb *phy, int on)
103{
104	u32 val;
105	int ret;
106
107	if (!phy->syscon_phy_power) {
108		omap_control_phy_power(phy->control_dev, on);
109		return 0;
110	}
111
112	if (on)
113		val = phy->power_on;
114	else
115		val = phy->power_off;
116
117	ret = regmap_update_bits(phy->syscon_phy_power, phy->power_reg,
118				 phy->mask, val);
119	return ret;
120}
121
122static int omap_usb_power_off(struct phy *x)
123{
124	struct omap_usb *phy = phy_get_drvdata(x);
125
126	return omap_usb_phy_power(phy, false);
127}
128
129static int omap_usb_power_on(struct phy *x)
130{
131	struct omap_usb *phy = phy_get_drvdata(x);
132
133	return omap_usb_phy_power(phy, true);
134}
135
136static int omap_usb2_disable_clocks(struct omap_usb *phy)
137{
138	clk_disable(phy->wkupclk);
139	if (!IS_ERR(phy->optclk))
140		clk_disable(phy->optclk);
141
142	return 0;
143}
144
145static int omap_usb2_enable_clocks(struct omap_usb *phy)
146{
147	int ret;
148
149	ret = clk_enable(phy->wkupclk);
150	if (ret < 0) {
151		dev_err(phy->dev, "Failed to enable wkupclk %d\n", ret);
152		goto err0;
153	}
154
155	if (!IS_ERR(phy->optclk)) {
156		ret = clk_enable(phy->optclk);
157		if (ret < 0) {
158			dev_err(phy->dev, "Failed to enable optclk %d\n", ret);
159			goto err1;
160		}
161	}
162
163	return 0;
164
165err1:
166	clk_disable(phy->wkupclk);
167
168err0:
169	return ret;
170}
171
172static int omap_usb_init(struct phy *x)
173{
174	struct omap_usb *phy = phy_get_drvdata(x);
175	u32 val;
176
177	omap_usb2_enable_clocks(phy);
178
179	if (phy->flags & OMAP_USB2_CALIBRATE_FALSE_DISCONNECT) {
180		/*
181		 *
182		 * Reduce the sensitivity of internal PHY by enabling the
183		 * DISCON_BYP_LATCH of the USB2PHY_ANA_CONFIG1 register. This
184		 * resolves issues with certain devices which can otherwise
185		 * be prone to false disconnects.
186		 *
187		 */
188		val = omap_usb_readl(phy->phy_base, USB2PHY_ANA_CONFIG1);
189		val |= USB2PHY_DISCON_BYP_LATCH;
190		omap_usb_writel(phy->phy_base, USB2PHY_ANA_CONFIG1, val);
191	}
192
193	return 0;
194}
195
196static int omap_usb_exit(struct phy *x)
197{
198	struct omap_usb *phy = phy_get_drvdata(x);
199
200	return omap_usb2_disable_clocks(phy);
201}
202
203static const struct phy_ops ops = {
204	.init		= omap_usb_init,
205	.exit		= omap_usb_exit,
206	.power_on	= omap_usb_power_on,
207	.power_off	= omap_usb_power_off,
208	.owner		= THIS_MODULE,
209};
210
211static const struct usb_phy_data omap_usb2_data = {
212	.label = "omap_usb2",
213	.flags = OMAP_USB2_HAS_START_SRP | OMAP_USB2_HAS_SET_VBUS,
214	.mask = OMAP_DEV_PHY_PD,
215	.power_off = OMAP_DEV_PHY_PD,
216};
217
218static const struct usb_phy_data omap5_usb2_data = {
219	.label = "omap5_usb2",
220	.flags = 0,
221	.mask = OMAP_DEV_PHY_PD,
222	.power_off = OMAP_DEV_PHY_PD,
223};
224
225static const struct usb_phy_data dra7x_usb2_data = {
226	.label = "dra7x_usb2",
227	.flags = OMAP_USB2_CALIBRATE_FALSE_DISCONNECT,
228	.mask = OMAP_DEV_PHY_PD,
229	.power_off = OMAP_DEV_PHY_PD,
230};
231
232static const struct usb_phy_data dra7x_usb2_phy2_data = {
233	.label = "dra7x_usb2_phy2",
234	.flags = OMAP_USB2_CALIBRATE_FALSE_DISCONNECT,
235	.mask = OMAP_USB2_PHY_PD,
236	.power_off = OMAP_USB2_PHY_PD,
237};
238
239static const struct usb_phy_data am437x_usb2_data = {
240	.label = "am437x_usb2",
241	.flags =  0,
242	.mask = AM437X_USB2_PHY_PD | AM437X_USB2_OTG_PD |
243		AM437X_USB2_OTGVDET_EN | AM437X_USB2_OTGSESSEND_EN,
244	.power_on = AM437X_USB2_OTGVDET_EN | AM437X_USB2_OTGSESSEND_EN,
245	.power_off = AM437X_USB2_PHY_PD | AM437X_USB2_OTG_PD,
246};
247
248static const struct of_device_id omap_usb2_id_table[] = {
249	{
250		.compatible = "ti,omap-usb2",
251		.data = &omap_usb2_data,
252	},
253	{
254		.compatible = "ti,omap5-usb2",
255		.data = &omap5_usb2_data,
256	},
257	{
258		.compatible = "ti,dra7x-usb2",
259		.data = &dra7x_usb2_data,
260	},
261	{
262		.compatible = "ti,dra7x-usb2-phy2",
263		.data = &dra7x_usb2_phy2_data,
264	},
265	{
266		.compatible = "ti,am437x-usb2",
267		.data = &am437x_usb2_data,
268	},
269	{},
270};
271MODULE_DEVICE_TABLE(of, omap_usb2_id_table);
272
273static int omap_usb2_probe(struct platform_device *pdev)
274{
275	struct omap_usb	*phy;
276	struct phy *generic_phy;
277	struct resource *res;
278	struct phy_provider *phy_provider;
279	struct usb_otg *otg;
280	struct device_node *node = pdev->dev.of_node;
281	struct device_node *control_node;
282	struct platform_device *control_pdev;
283	const struct of_device_id *of_id;
284	struct usb_phy_data *phy_data;
285
286	of_id = of_match_device(omap_usb2_id_table, &pdev->dev);
287
288	if (!of_id)
289		return -EINVAL;
290
291	phy_data = (struct usb_phy_data *)of_id->data;
292
293	phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
294	if (!phy)
295		return -ENOMEM;
296
297	otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
298	if (!otg)
299		return -ENOMEM;
300
301	phy->dev		= &pdev->dev;
302
303	phy->phy.dev		= phy->dev;
304	phy->phy.label		= phy_data->label;
305	phy->phy.otg		= otg;
306	phy->phy.type		= USB_PHY_TYPE_USB2;
307	phy->mask		= phy_data->mask;
308	phy->power_on		= phy_data->power_on;
309	phy->power_off		= phy_data->power_off;
310
311	if (phy_data->flags & OMAP_USB2_CALIBRATE_FALSE_DISCONNECT) {
312		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
313		phy->phy_base = devm_ioremap_resource(&pdev->dev, res);
314		if (IS_ERR(phy->phy_base))
315			return PTR_ERR(phy->phy_base);
316		phy->flags |= OMAP_USB2_CALIBRATE_FALSE_DISCONNECT;
317	}
318
319	phy->syscon_phy_power = syscon_regmap_lookup_by_phandle(node,
320							"syscon-phy-power");
321	if (IS_ERR(phy->syscon_phy_power)) {
322		dev_dbg(&pdev->dev,
323			"can't get syscon-phy-power, using control device\n");
324		phy->syscon_phy_power = NULL;
325
326		control_node = of_parse_phandle(node, "ctrl-module", 0);
327		if (!control_node) {
328			dev_err(&pdev->dev,
329				"Failed to get control device phandle\n");
330			return -EINVAL;
331		}
332
333		control_pdev = of_find_device_by_node(control_node);
334		if (!control_pdev) {
335			dev_err(&pdev->dev, "Failed to get control device\n");
336			return -EINVAL;
337		}
338		phy->control_dev = &control_pdev->dev;
339	} else {
340		if (of_property_read_u32_index(node,
341					       "syscon-phy-power", 1,
342					       &phy->power_reg)) {
343			dev_err(&pdev->dev,
344				"couldn't get power reg. offset\n");
345			return -EINVAL;
346		}
347	}
348
349	otg->set_host		= omap_usb_set_host;
350	otg->set_peripheral	= omap_usb_set_peripheral;
351	if (phy_data->flags & OMAP_USB2_HAS_SET_VBUS)
352		otg->set_vbus		= omap_usb_set_vbus;
353	if (phy_data->flags & OMAP_USB2_HAS_START_SRP)
354		otg->start_srp		= omap_usb_start_srp;
355	otg->usb_phy		= &phy->phy;
356
357	platform_set_drvdata(pdev, phy);
358	pm_runtime_enable(phy->dev);
359
360	generic_phy = devm_phy_create(phy->dev, NULL, &ops);
361	if (IS_ERR(generic_phy)) {
362		pm_runtime_disable(phy->dev);
363		return PTR_ERR(generic_phy);
364	}
365
366	phy_set_drvdata(generic_phy, phy);
367	omap_usb_power_off(generic_phy);
368
369	phy_provider = devm_of_phy_provider_register(phy->dev,
370			of_phy_simple_xlate);
371	if (IS_ERR(phy_provider)) {
372		pm_runtime_disable(phy->dev);
373		return PTR_ERR(phy_provider);
374	}
375
376	phy->wkupclk = devm_clk_get(phy->dev, "wkupclk");
377	if (IS_ERR(phy->wkupclk)) {
378		dev_warn(&pdev->dev, "unable to get wkupclk, trying old name\n");
379		phy->wkupclk = devm_clk_get(phy->dev, "usb_phy_cm_clk32k");
380		if (IS_ERR(phy->wkupclk)) {
381			dev_err(&pdev->dev, "unable to get usb_phy_cm_clk32k\n");
382			pm_runtime_disable(phy->dev);
383			return PTR_ERR(phy->wkupclk);
384		} else {
385			dev_warn(&pdev->dev,
386				 "found usb_phy_cm_clk32k, please fix DTS\n");
387		}
388	}
389	clk_prepare(phy->wkupclk);
390
391	phy->optclk = devm_clk_get(phy->dev, "refclk");
392	if (IS_ERR(phy->optclk)) {
393		dev_dbg(&pdev->dev, "unable to get refclk, trying old name\n");
394		phy->optclk = devm_clk_get(phy->dev, "usb_otg_ss_refclk960m");
395		if (IS_ERR(phy->optclk)) {
396			dev_dbg(&pdev->dev,
397				"unable to get usb_otg_ss_refclk960m\n");
398		} else {
399			dev_warn(&pdev->dev,
400				 "found usb_otg_ss_refclk960m, please fix DTS\n");
401		}
402	}
403
404	if (!IS_ERR(phy->optclk))
405		clk_prepare(phy->optclk);
406
407	usb_add_phy_dev(&phy->phy);
408
409	return 0;
410}
411
412static int omap_usb2_remove(struct platform_device *pdev)
413{
414	struct omap_usb	*phy = platform_get_drvdata(pdev);
415
416	clk_unprepare(phy->wkupclk);
417	if (!IS_ERR(phy->optclk))
418		clk_unprepare(phy->optclk);
419	usb_remove_phy(&phy->phy);
420	pm_runtime_disable(phy->dev);
421
422	return 0;
423}
424
425static struct platform_driver omap_usb2_driver = {
426	.probe		= omap_usb2_probe,
427	.remove		= omap_usb2_remove,
428	.driver		= {
429		.name	= "omap-usb2",
430		.of_match_table = omap_usb2_id_table,
431	},
432};
433
434module_platform_driver(omap_usb2_driver);
435
436MODULE_ALIAS("platform:omap_usb2");
437MODULE_AUTHOR("Texas Instruments Inc.");
438MODULE_DESCRIPTION("OMAP USB2 phy driver");
439MODULE_LICENSE("GPL v2");