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1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Intel LGM USB PHY driver | |
4 | * | |
5 | * Copyright (C) 2020 Intel Corporation. | |
6 | */ | |
7 | ||
8 | #include <linux/bitfield.h> | |
9 | #include <linux/delay.h> | |
10 | #include <linux/iopoll.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/of.h> | |
13 | #include <linux/platform_device.h> | |
14 | #include <linux/regulator/consumer.h> | |
15 | #include <linux/reset.h> | |
16 | #include <linux/usb/phy.h> | |
17 | #include <linux/workqueue.h> | |
18 | ||
19 | #define CTRL1_OFFSET 0x14 | |
20 | #define SRAM_EXT_LD_DONE BIT(25) | |
21 | #define SRAM_INIT_DONE BIT(26) | |
22 | ||
23 | #define TCPC_OFFSET 0x1014 | |
24 | #define TCPC_MUX_CTL GENMASK(1, 0) | |
25 | #define MUX_NC 0 | |
26 | #define MUX_USB 1 | |
27 | #define MUX_DP 2 | |
28 | #define MUX_USBDP 3 | |
29 | #define TCPC_FLIPPED BIT(2) | |
30 | #define TCPC_LOW_POWER_EN BIT(3) | |
31 | #define TCPC_VALID BIT(4) | |
32 | #define TCPC_CONN \ | |
33 | (TCPC_VALID | FIELD_PREP(TCPC_MUX_CTL, MUX_USB)) | |
34 | #define TCPC_DISCONN \ | |
35 | (TCPC_VALID | FIELD_PREP(TCPC_MUX_CTL, MUX_NC) | TCPC_LOW_POWER_EN) | |
36 | ||
37 | static const char *const PHY_RESETS[] = { "phy31", "phy", }; | |
38 | static const char *const CTL_RESETS[] = { "apb", "ctrl", }; | |
39 | ||
40 | struct tca_apb { | |
41 | struct reset_control *resets[ARRAY_SIZE(PHY_RESETS)]; | |
42 | struct regulator *vbus; | |
43 | struct work_struct wk; | |
44 | struct usb_phy phy; | |
45 | ||
46 | bool regulator_enabled; | |
47 | bool phy_initialized; | |
48 | bool connected; | |
49 | }; | |
50 | ||
51 | static int get_flipped(struct tca_apb *ta, bool *flipped) | |
52 | { | |
53 | union extcon_property_value property; | |
54 | int ret; | |
55 | ||
56 | ret = extcon_get_property(ta->phy.edev, EXTCON_USB_HOST, | |
57 | EXTCON_PROP_USB_TYPEC_POLARITY, &property); | |
58 | if (ret) { | |
59 | dev_err(ta->phy.dev, "no polarity property from extcon\n"); | |
60 | return ret; | |
61 | } | |
62 | ||
63 | *flipped = property.intval; | |
64 | ||
65 | return 0; | |
66 | } | |
67 | ||
68 | static int phy_init(struct usb_phy *phy) | |
69 | { | |
70 | struct tca_apb *ta = container_of(phy, struct tca_apb, phy); | |
71 | void __iomem *ctrl1 = phy->io_priv + CTRL1_OFFSET; | |
72 | int val, ret, i; | |
73 | ||
74 | if (ta->phy_initialized) | |
75 | return 0; | |
76 | ||
77 | for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++) | |
78 | reset_control_deassert(ta->resets[i]); | |
79 | ||
80 | ret = readl_poll_timeout(ctrl1, val, val & SRAM_INIT_DONE, 10, 10 * 1000); | |
81 | if (ret) { | |
82 | dev_err(ta->phy.dev, "SRAM init failed, 0x%x\n", val); | |
83 | return ret; | |
84 | } | |
85 | ||
86 | writel(readl(ctrl1) | SRAM_EXT_LD_DONE, ctrl1); | |
87 | ||
88 | ta->phy_initialized = true; | |
89 | if (!ta->phy.edev) { | |
90 | writel(TCPC_CONN, ta->phy.io_priv + TCPC_OFFSET); | |
91 | return phy->set_vbus(phy, true); | |
92 | } | |
93 | ||
94 | schedule_work(&ta->wk); | |
95 | ||
96 | return ret; | |
97 | } | |
98 | ||
99 | static void phy_shutdown(struct usb_phy *phy) | |
100 | { | |
101 | struct tca_apb *ta = container_of(phy, struct tca_apb, phy); | |
102 | int i; | |
103 | ||
104 | if (!ta->phy_initialized) | |
105 | return; | |
106 | ||
107 | ta->phy_initialized = false; | |
108 | flush_work(&ta->wk); | |
109 | ta->phy.set_vbus(&ta->phy, false); | |
110 | ||
111 | ta->connected = false; | |
112 | writel(TCPC_DISCONN, ta->phy.io_priv + TCPC_OFFSET); | |
113 | ||
114 | for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++) | |
115 | reset_control_assert(ta->resets[i]); | |
116 | } | |
117 | ||
118 | static int phy_set_vbus(struct usb_phy *phy, int on) | |
119 | { | |
120 | struct tca_apb *ta = container_of(phy, struct tca_apb, phy); | |
121 | int ret; | |
122 | ||
123 | if (!!on == ta->regulator_enabled) | |
124 | return 0; | |
125 | ||
126 | if (on) | |
127 | ret = regulator_enable(ta->vbus); | |
128 | else | |
129 | ret = regulator_disable(ta->vbus); | |
130 | ||
131 | if (!ret) | |
132 | ta->regulator_enabled = on; | |
133 | ||
134 | dev_dbg(ta->phy.dev, "set vbus: %d\n", on); | |
135 | return ret; | |
136 | } | |
137 | ||
138 | static void tca_work(struct work_struct *work) | |
139 | { | |
140 | struct tca_apb *ta = container_of(work, struct tca_apb, wk); | |
141 | bool connected; | |
142 | bool flipped = false; | |
143 | u32 val; | |
144 | int ret; | |
145 | ||
146 | ret = get_flipped(ta, &flipped); | |
147 | if (ret) | |
148 | return; | |
149 | ||
150 | connected = extcon_get_state(ta->phy.edev, EXTCON_USB_HOST); | |
151 | if (connected == ta->connected) | |
152 | return; | |
153 | ||
154 | ta->connected = connected; | |
155 | if (connected) { | |
156 | val = TCPC_CONN; | |
157 | if (flipped) | |
158 | val |= TCPC_FLIPPED; | |
159 | dev_dbg(ta->phy.dev, "connected%s\n", flipped ? " flipped" : ""); | |
160 | } else { | |
161 | val = TCPC_DISCONN; | |
162 | dev_dbg(ta->phy.dev, "disconnected\n"); | |
163 | } | |
164 | ||
165 | writel(val, ta->phy.io_priv + TCPC_OFFSET); | |
166 | ||
167 | ret = ta->phy.set_vbus(&ta->phy, connected); | |
168 | if (ret) | |
169 | dev_err(ta->phy.dev, "failed to set VBUS\n"); | |
170 | } | |
171 | ||
172 | static int id_notifier(struct notifier_block *nb, unsigned long event, void *ptr) | |
173 | { | |
174 | struct tca_apb *ta = container_of(nb, struct tca_apb, phy.id_nb); | |
175 | ||
176 | if (ta->phy_initialized) | |
177 | schedule_work(&ta->wk); | |
178 | ||
179 | return NOTIFY_DONE; | |
180 | } | |
181 | ||
182 | static int vbus_notifier(struct notifier_block *nb, unsigned long evnt, void *ptr) | |
183 | { | |
184 | return NOTIFY_DONE; | |
185 | } | |
186 | ||
187 | static int phy_probe(struct platform_device *pdev) | |
188 | { | |
189 | struct reset_control *resets[ARRAY_SIZE(CTL_RESETS)]; | |
190 | struct device *dev = &pdev->dev; | |
191 | struct usb_phy *phy; | |
192 | struct tca_apb *ta; | |
193 | int i; | |
194 | ||
195 | ta = devm_kzalloc(dev, sizeof(*ta), GFP_KERNEL); | |
196 | if (!ta) | |
197 | return -ENOMEM; | |
198 | ||
199 | platform_set_drvdata(pdev, ta); | |
200 | INIT_WORK(&ta->wk, tca_work); | |
201 | ||
202 | phy = &ta->phy; | |
203 | phy->dev = dev; | |
204 | phy->label = dev_name(dev); | |
205 | phy->type = USB_PHY_TYPE_USB3; | |
206 | phy->init = phy_init; | |
207 | phy->shutdown = phy_shutdown; | |
208 | phy->set_vbus = phy_set_vbus; | |
209 | phy->id_nb.notifier_call = id_notifier; | |
210 | phy->vbus_nb.notifier_call = vbus_notifier; | |
211 | ||
212 | phy->io_priv = devm_platform_ioremap_resource(pdev, 0); | |
213 | if (IS_ERR(phy->io_priv)) | |
214 | return PTR_ERR(phy->io_priv); | |
215 | ||
216 | ta->vbus = devm_regulator_get(dev, "vbus"); | |
217 | if (IS_ERR(ta->vbus)) | |
218 | return PTR_ERR(ta->vbus); | |
219 | ||
220 | for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++) { | |
221 | resets[i] = devm_reset_control_get_exclusive(dev, CTL_RESETS[i]); | |
222 | if (IS_ERR(resets[i])) { | |
223 | dev_err(dev, "%s reset not found\n", CTL_RESETS[i]); | |
224 | return PTR_ERR(resets[i]); | |
225 | } | |
226 | } | |
227 | ||
228 | for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++) { | |
229 | ta->resets[i] = devm_reset_control_get_exclusive(dev, PHY_RESETS[i]); | |
230 | if (IS_ERR(ta->resets[i])) { | |
231 | dev_err(dev, "%s reset not found\n", PHY_RESETS[i]); | |
232 | return PTR_ERR(ta->resets[i]); | |
233 | } | |
234 | } | |
235 | ||
236 | for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++) | |
237 | reset_control_assert(resets[i]); | |
238 | ||
239 | for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++) | |
240 | reset_control_assert(ta->resets[i]); | |
241 | /* | |
242 | * Out-of-band reset of the controller after PHY reset will cause | |
243 | * controller malfunctioning, so we should use in-band controller | |
244 | * reset only and leave the controller de-asserted here. | |
245 | */ | |
246 | for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++) | |
247 | reset_control_deassert(resets[i]); | |
248 | ||
249 | /* Need to wait at least 20us after de-assert the controller */ | |
250 | usleep_range(20, 100); | |
251 | ||
252 | return usb_add_phy_dev(phy); | |
253 | } | |
254 | ||
255 | static int phy_remove(struct platform_device *pdev) | |
256 | { | |
257 | struct tca_apb *ta = platform_get_drvdata(pdev); | |
258 | ||
259 | usb_remove_phy(&ta->phy); | |
260 | ||
261 | return 0; | |
262 | } | |
263 | ||
264 | static const struct of_device_id intel_usb_phy_dt_ids[] = { | |
265 | { .compatible = "intel,lgm-usb-phy" }, | |
266 | { } | |
267 | }; | |
268 | MODULE_DEVICE_TABLE(of, intel_usb_phy_dt_ids); | |
269 | ||
270 | static struct platform_driver lgm_phy_driver = { | |
271 | .driver = { | |
272 | .name = "lgm-usb-phy", | |
273 | .of_match_table = intel_usb_phy_dt_ids, | |
274 | }, | |
275 | .probe = phy_probe, | |
276 | .remove = phy_remove, | |
277 | }; | |
278 | ||
279 | module_platform_driver(lgm_phy_driver); | |
280 | ||
281 | MODULE_DESCRIPTION("Intel LGM USB PHY driver"); | |
282 | MODULE_AUTHOR("Li Yin <yin1.li@intel.com>"); | |
283 | MODULE_AUTHOR("Vadivel Murugan R <vadivel.muruganx.ramuthevar@linux.intel.com>"); | |
284 | MODULE_LICENSE("GPL v2"); |