blob: 7b42555ddd51aac0d44714ef2254278d3fe59215 [file] [log] [blame]
Tony Lindgren609adde2015-03-19 17:08:07 -07001/*
2 * This program is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU General Public License as
4 * published by the Free Software Foundation version 2.
5 *
6 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
7 * kind, whether express or implied; without even the implied warranty
8 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 */
11
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/regmap.h>
15
16#include <linux/slab.h>
17#include <linux/of.h>
18#include <linux/io.h>
19#include <linux/usb/phy_companion.h>
20#include <linux/clk.h>
21#include <linux/err.h>
22#include <linux/pm_runtime.h>
23#include <linux/delay.h>
24#include <linux/phy/phy.h>
25#include <linux/of_platform.h>
26
27#include <linux/mfd/syscon.h>
28
29/*
30 * TRM has two sets of USB_CTRL registers.. The correct register bits
31 * are in TRM section 24.9.8.2 USB_CTRL Register. The TRM documents the
32 * phy as being SR70LX Synopsys USB 2.0 OTG nanoPHY. It also seems at
33 * least dm816x rev c ignores writes to USB_CTRL register, but the TI
34 * kernel is writing to those so it's possible that later revisions
35 * have worknig USB_CTRL register.
36 *
37 * Also note that At least USB_CTRL register seems to be dm816x specific
38 * according to the TRM. It's possible that USBPHY_CTRL is more generic,
39 * but that would have to be checked against the SR70LX documentation
40 * which does not seem to be publicly available.
41 *
42 * Finally, the phy on dm814x and am335x is different from dm816x.
43 */
44#define DM816X_USB_CTRL_PHYCLKSRC BIT(8) /* 1 = PLL ref clock */
45#define DM816X_USB_CTRL_PHYSLEEP1 BIT(1) /* Enable the first phy */
46#define DM816X_USB_CTRL_PHYSLEEP0 BIT(0) /* Enable the second phy */
47
48#define DM816X_USBPHY_CTRL_TXRISETUNE 1
49#define DM816X_USBPHY_CTRL_TXVREFTUNE 0xc
50#define DM816X_USBPHY_CTRL_TXPREEMTUNE 0x2
51
52struct dm816x_usb_phy {
53 struct regmap *syscon;
54 struct device *dev;
55 unsigned int instance;
56 struct clk *refclk;
57 struct usb_phy phy;
58 unsigned int usb_ctrl; /* Shared between phy0 and phy1 */
59 unsigned int usbphy_ctrl;
60};
61
62static int dm816x_usb_phy_set_host(struct usb_otg *otg, struct usb_bus *host)
63{
64 otg->host = host;
65 if (!host)
66 otg->state = OTG_STATE_UNDEFINED;
67
68 return 0;
69}
70
71static int dm816x_usb_phy_set_peripheral(struct usb_otg *otg,
72 struct usb_gadget *gadget)
73{
74 otg->gadget = gadget;
75 if (!gadget)
76 otg->state = OTG_STATE_UNDEFINED;
77
78 return 0;
79}
80
81static int dm816x_usb_phy_init(struct phy *x)
82{
83 struct dm816x_usb_phy *phy = phy_get_drvdata(x);
84 unsigned int val;
85 int error;
86
87 if (clk_get_rate(phy->refclk) != 24000000)
88 dev_warn(phy->dev, "nonstandard phy refclk\n");
89
90 /* Set PLL ref clock and put phys to sleep */
91 error = regmap_update_bits(phy->syscon, phy->usb_ctrl,
92 DM816X_USB_CTRL_PHYCLKSRC |
93 DM816X_USB_CTRL_PHYSLEEP1 |
94 DM816X_USB_CTRL_PHYSLEEP0,
95 0);
96 regmap_read(phy->syscon, phy->usb_ctrl, &val);
97 if ((val & 3) != 0)
98 dev_info(phy->dev,
99 "Working dm816x USB_CTRL! (0x%08x)\n",
100 val);
101
102 /*
103 * TI kernel sets these values for "symmetrical eye diagram and
104 * better signal quality" so let's assume somebody checked the
105 * values with a scope and set them here too.
106 */
107 regmap_read(phy->syscon, phy->usbphy_ctrl, &val);
108 val |= DM816X_USBPHY_CTRL_TXRISETUNE |
109 DM816X_USBPHY_CTRL_TXVREFTUNE |
110 DM816X_USBPHY_CTRL_TXPREEMTUNE;
111 regmap_write(phy->syscon, phy->usbphy_ctrl, val);
112
113 return 0;
114}
115
116static struct phy_ops ops = {
117 .init = dm816x_usb_phy_init,
118 .owner = THIS_MODULE,
119};
120
121static int dm816x_usb_phy_runtime_suspend(struct device *dev)
122{
123 struct dm816x_usb_phy *phy = dev_get_drvdata(dev);
124 unsigned int mask, val;
125 int error = 0;
126
127 mask = BIT(phy->instance);
128 val = ~BIT(phy->instance);
129 error = regmap_update_bits(phy->syscon, phy->usb_ctrl,
130 mask, val);
131 if (error)
132 dev_err(phy->dev, "phy%i failed to power off\n",
133 phy->instance);
134 clk_disable(phy->refclk);
135
136 return 0;
137}
138
139static int dm816x_usb_phy_runtime_resume(struct device *dev)
140{
141 struct dm816x_usb_phy *phy = dev_get_drvdata(dev);
142 unsigned int mask, val;
143 int error;
144
145 error = clk_enable(phy->refclk);
146 if (error)
147 return error;
148
149 /*
150 * Note that at least dm816x rev c does not seem to do
151 * anything with the USB_CTRL register. But let's follow
152 * what the TI tree is doing in case later revisions use
153 * USB_CTRL.
154 */
155 mask = BIT(phy->instance);
156 val = BIT(phy->instance);
157 error = regmap_update_bits(phy->syscon, phy->usb_ctrl,
158 mask, val);
159 if (error) {
160 dev_err(phy->dev, "phy%i failed to power on\n",
161 phy->instance);
162 clk_disable(phy->refclk);
163 return error;
164 }
165
166 return 0;
167}
168
169static UNIVERSAL_DEV_PM_OPS(dm816x_usb_phy_pm_ops,
170 dm816x_usb_phy_runtime_suspend,
171 dm816x_usb_phy_runtime_resume,
172 NULL);
173
174#ifdef CONFIG_OF
175static const struct of_device_id dm816x_usb_phy_id_table[] = {
176 {
177 .compatible = "ti,dm8168-usb-phy",
178 },
179 {},
180};
181MODULE_DEVICE_TABLE(of, dm816x_usb_phy_id_table);
182#endif
183
184static int dm816x_usb_phy_probe(struct platform_device *pdev)
185{
186 struct dm816x_usb_phy *phy;
187 struct resource *res;
188 struct phy *generic_phy;
189 struct phy_provider *phy_provider;
190 struct usb_otg *otg;
191 const struct of_device_id *of_id;
192 const struct usb_phy_data *phy_data;
193 int error;
194
195 of_id = of_match_device(of_match_ptr(dm816x_usb_phy_id_table),
196 &pdev->dev);
197 if (!of_id)
198 return -EINVAL;
199
200 phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
201 if (!phy)
202 return -ENOMEM;
203
204 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
205 if (!res)
206 return -ENOENT;
207
208 phy->syscon = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
209 "syscon");
210 if (IS_ERR(phy->syscon))
211 return PTR_ERR(phy->syscon);
212
213 /*
214 * According to sprs614e.pdf, the first usb_ctrl is shared and
215 * the second instance for usb_ctrl is reserved.. Also the
216 * register bits are different from earlier TRMs.
217 */
218 phy->usb_ctrl = 0x20;
219 phy->usbphy_ctrl = (res->start & 0xff) + 4;
220 if (phy->usbphy_ctrl == 0x2c)
221 phy->instance = 1;
222
223 phy_data = of_id->data;
224
225 otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
226 if (!otg)
227 return -ENOMEM;
228
229 phy->dev = &pdev->dev;
230 phy->phy.dev = phy->dev;
231 phy->phy.label = "dm8168_usb_phy";
232 phy->phy.otg = otg;
233 phy->phy.type = USB_PHY_TYPE_USB2;
234 otg->set_host = dm816x_usb_phy_set_host;
235 otg->set_peripheral = dm816x_usb_phy_set_peripheral;
236 otg->usb_phy = &phy->phy;
237
238 platform_set_drvdata(pdev, phy);
239
240 phy->refclk = devm_clk_get(phy->dev, "refclk");
241 if (IS_ERR(phy->refclk))
242 return PTR_ERR(phy->refclk);
243 error = clk_prepare(phy->refclk);
244 if (error)
245 return error;
246
247 pm_runtime_enable(phy->dev);
248 generic_phy = devm_phy_create(phy->dev, NULL, &ops);
249 if (IS_ERR(generic_phy))
250 return PTR_ERR(generic_phy);
251
252 phy_set_drvdata(generic_phy, phy);
253
254 phy_provider = devm_of_phy_provider_register(phy->dev,
255 of_phy_simple_xlate);
256 if (IS_ERR(phy_provider))
257 return PTR_ERR(phy_provider);
258
259 usb_add_phy_dev(&phy->phy);
260
261 return 0;
262}
263
264static int dm816x_usb_phy_remove(struct platform_device *pdev)
265{
266 struct dm816x_usb_phy *phy = platform_get_drvdata(pdev);
267
268 usb_remove_phy(&phy->phy);
269 pm_runtime_disable(phy->dev);
270 clk_unprepare(phy->refclk);
271
272 return 0;
273}
274
275static struct platform_driver dm816x_usb_phy_driver = {
276 .probe = dm816x_usb_phy_probe,
277 .remove = dm816x_usb_phy_remove,
278 .driver = {
279 .name = "dm816x-usb-phy",
280 .pm = &dm816x_usb_phy_pm_ops,
281 .of_match_table = of_match_ptr(dm816x_usb_phy_id_table),
282 },
283};
284
285module_platform_driver(dm816x_usb_phy_driver);
286
287MODULE_ALIAS("platform:dm816x_usb");
288MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
289MODULE_DESCRIPTION("dm816x usb phy driver");
290MODULE_LICENSE("GPL v2");