1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * PolarFire SoC (MPFS) MUSB Glue Layer
4 *
5 * Copyright (c) 2020-2022 Microchip Corporation. All rights reserved.
6 * Based on {omap2430,tusb6010,ux500}.c
7 *
8 */
9
10 #include <linux/clk.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/platform_device.h>
18 #include <linux/usb/usb_phy_generic.h>
19 #include "musb_core.h"
20 #include "musb_dma.h"
21
22 #define MPFS_MUSB_MAX_EP_NUM 8
23 #define MPFS_MUSB_RAM_BITS 12
24
25 struct mpfs_glue {
26 struct device *dev;
27 struct platform_device *musb;
28 struct platform_device *phy;
29 struct clk *clk;
30 };
31
32 static struct musb_fifo_cfg mpfs_musb_mode_cfg[] = {
33 { .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
34 { .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
35 { .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 512, },
36 { .hw_ep_num = 2, .style = FIFO_RX, .maxpacket = 512, },
37 { .hw_ep_num = 3, .style = FIFO_TX, .maxpacket = 512, },
38 { .hw_ep_num = 3, .style = FIFO_RX, .maxpacket = 512, },
39 { .hw_ep_num = 4, .style = FIFO_TX, .maxpacket = 1024, },
40 { .hw_ep_num = 4, .style = FIFO_RX, .maxpacket = 4096, },
41 };
42
43 static const struct musb_hdrc_config mpfs_musb_hdrc_config = {
44 .fifo_cfg = mpfs_musb_mode_cfg,
45 .fifo_cfg_size = ARRAY_SIZE(mpfs_musb_mode_cfg),
46 .multipoint = true,
47 .dyn_fifo = true,
48 .num_eps = MPFS_MUSB_MAX_EP_NUM,
49 .ram_bits = MPFS_MUSB_RAM_BITS,
50 };
51
mpfs_musb_set_vbus(struct musb * musb,int is_on)52 static void mpfs_musb_set_vbus(struct musb *musb, int is_on)
53 {
54 u8 devctl;
55
56 /*
57 * HDRC controls CPEN, but beware current surges during device
58 * connect. They can trigger transient overcurrent conditions
59 * that must be ignored.
60 */
61 devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
62
63 if (is_on) {
64 musb->is_active = 1;
65 musb->xceiv->otg->default_a = 1;
66 musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
67 devctl |= MUSB_DEVCTL_SESSION;
68 MUSB_HST_MODE(musb);
69 } else {
70 musb->is_active = 0;
71
72 /*
73 * NOTE: skipping A_WAIT_VFALL -> A_IDLE and
74 * jumping right to B_IDLE...
75 */
76 musb->xceiv->otg->default_a = 0;
77 musb->xceiv->otg->state = OTG_STATE_B_IDLE;
78 devctl &= ~MUSB_DEVCTL_SESSION;
79
80 MUSB_DEV_MODE(musb);
81 }
82
83 musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
84
85 dev_dbg(musb->controller, "VBUS %s, devctl %02x\n",
86 usb_otg_state_string(musb->xceiv->otg->state),
87 musb_readb(musb->mregs, MUSB_DEVCTL));
88 }
89
90 #define POLL_SECONDS 2
91
otg_timer(struct timer_list * t)92 static void otg_timer(struct timer_list *t)
93 {
94 struct musb *musb = from_timer(musb, t, dev_timer);
95 void __iomem *mregs = musb->mregs;
96 u8 devctl;
97 unsigned long flags;
98
99 /*
100 * We poll because PolarFire SoC won't expose several OTG-critical
101 * status change events (from the transceiver) otherwise.
102 */
103 devctl = musb_readb(mregs, MUSB_DEVCTL);
104 dev_dbg(musb->controller, "Poll devctl %02x (%s)\n", devctl,
105 usb_otg_state_string(musb->xceiv->otg->state));
106
107 spin_lock_irqsave(&musb->lock, flags);
108 switch (musb->xceiv->otg->state) {
109 case OTG_STATE_A_WAIT_BCON:
110 devctl &= ~MUSB_DEVCTL_SESSION;
111 musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
112
113 devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
114 if (devctl & MUSB_DEVCTL_BDEVICE) {
115 musb->xceiv->otg->state = OTG_STATE_B_IDLE;
116 MUSB_DEV_MODE(musb);
117 mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
118 } else {
119 musb->xceiv->otg->state = OTG_STATE_A_IDLE;
120 MUSB_HST_MODE(musb);
121 }
122 break;
123 case OTG_STATE_A_WAIT_VFALL:
124 if (devctl & MUSB_DEVCTL_VBUS) {
125 mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
126 break;
127 }
128 musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
129 break;
130 case OTG_STATE_B_IDLE:
131 /*
132 * There's no ID-changed IRQ, so we have no good way to tell
133 * when to switch to the A-Default state machine (by setting
134 * the DEVCTL.Session bit).
135 *
136 * Workaround: whenever we're in B_IDLE, try setting the
137 * session flag every few seconds. If it works, ID was
138 * grounded and we're now in the A-Default state machine.
139 *
140 * NOTE: setting the session flag is _supposed_ to trigger
141 * SRP but clearly it doesn't.
142 */
143 musb_writeb(mregs, MUSB_DEVCTL, devctl | MUSB_DEVCTL_SESSION);
144 devctl = musb_readb(mregs, MUSB_DEVCTL);
145 if (devctl & MUSB_DEVCTL_BDEVICE)
146 mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
147 else
148 musb->xceiv->otg->state = OTG_STATE_A_IDLE;
149 break;
150 default:
151 break;
152 }
153 spin_unlock_irqrestore(&musb->lock, flags);
154 }
155
mpfs_musb_try_idle(struct musb * musb,unsigned long timeout)156 static void __maybe_unused mpfs_musb_try_idle(struct musb *musb, unsigned long timeout)
157 {
158 static unsigned long last_timer;
159
160 if (timeout == 0)
161 timeout = jiffies + msecs_to_jiffies(3);
162
163 /* Never idle if active, or when VBUS timeout is not set as host */
164 if (musb->is_active || (musb->a_wait_bcon == 0 &&
165 musb->xceiv->otg->state == OTG_STATE_A_WAIT_BCON)) {
166 dev_dbg(musb->controller, "%s active, deleting timer\n",
167 usb_otg_state_string(musb->xceiv->otg->state));
168 del_timer(&musb->dev_timer);
169 last_timer = jiffies;
170 return;
171 }
172
173 if (time_after(last_timer, timeout) && timer_pending(&musb->dev_timer)) {
174 dev_dbg(musb->controller, "Longer idle timer already pending, ignoring...\n");
175 return;
176 }
177 last_timer = timeout;
178
179 dev_dbg(musb->controller, "%s inactive, starting idle timer for %u ms\n",
180 usb_otg_state_string(musb->xceiv->otg->state),
181 jiffies_to_msecs(timeout - jiffies));
182 mod_timer(&musb->dev_timer, timeout);
183 }
184
mpfs_musb_interrupt(int irq,void * __hci)185 static irqreturn_t mpfs_musb_interrupt(int irq, void *__hci)
186 {
187 unsigned long flags;
188 irqreturn_t ret = IRQ_NONE;
189 struct musb *musb = __hci;
190
191 spin_lock_irqsave(&musb->lock, flags);
192
193 musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
194 musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);
195 musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX);
196
197 if (musb->int_usb || musb->int_tx || musb->int_rx) {
198 musb_writeb(musb->mregs, MUSB_INTRUSB, musb->int_usb);
199 musb_writew(musb->mregs, MUSB_INTRTX, musb->int_tx);
200 musb_writew(musb->mregs, MUSB_INTRRX, musb->int_rx);
201 ret = musb_interrupt(musb);
202 }
203
204 /* Poll for ID change */
205 if (musb->xceiv->otg->state == OTG_STATE_B_IDLE)
206 mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
207
208 spin_unlock_irqrestore(&musb->lock, flags);
209
210 return ret;
211 }
212
mpfs_musb_init(struct musb * musb)213 static int mpfs_musb_init(struct musb *musb)
214 {
215 struct device *dev = musb->controller;
216
217 musb->xceiv = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
218 if (IS_ERR(musb->xceiv)) {
219 dev_err(dev, "HS UDC: no transceiver configured\n");
220 return PTR_ERR(musb->xceiv);
221 }
222
223 timer_setup(&musb->dev_timer, otg_timer, 0);
224
225 musb->dyn_fifo = true;
226 musb->isr = mpfs_musb_interrupt;
227
228 musb_platform_set_vbus(musb, 1);
229
230 return 0;
231 }
232
mpfs_musb_exit(struct musb * musb)233 static int mpfs_musb_exit(struct musb *musb)
234 {
235 del_timer_sync(&musb->dev_timer);
236
237 return 0;
238 }
239
240 static const struct musb_platform_ops mpfs_ops = {
241 .quirks = MUSB_DMA_INVENTRA,
242 .init = mpfs_musb_init,
243 .exit = mpfs_musb_exit,
244 .fifo_mode = 2,
245 #ifdef CONFIG_USB_INVENTRA_DMA
246 .dma_init = musbhs_dma_controller_create,
247 .dma_exit = musbhs_dma_controller_destroy,
248 #endif
249 #ifndef CONFIG_USB_MUSB_HOST
250 .try_idle = mpfs_musb_try_idle,
251 #endif
252 .set_vbus = mpfs_musb_set_vbus
253 };
254
mpfs_probe(struct platform_device * pdev)255 static int mpfs_probe(struct platform_device *pdev)
256 {
257 struct musb_hdrc_platform_data *pdata = dev_get_platdata(&pdev->dev);
258 struct mpfs_glue *glue;
259 struct platform_device *musb_pdev;
260 struct device *dev = &pdev->dev;
261 struct clk *clk;
262 int ret;
263
264 glue = devm_kzalloc(dev, sizeof(*glue), GFP_KERNEL);
265 if (!glue)
266 return -ENOMEM;
267
268 musb_pdev = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
269 if (!musb_pdev) {
270 dev_err(dev, "failed to allocate musb device\n");
271 return -ENOMEM;
272 }
273
274 clk = devm_clk_get(&pdev->dev, NULL);
275 if (IS_ERR(clk)) {
276 dev_err(&pdev->dev, "failed to get clock\n");
277 ret = PTR_ERR(clk);
278 goto err_phy_release;
279 }
280
281 ret = clk_prepare_enable(clk);
282 if (ret) {
283 dev_err(&pdev->dev, "failed to enable clock\n");
284 goto err_phy_release;
285 }
286
287 musb_pdev->dev.parent = dev;
288 musb_pdev->dev.coherent_dma_mask = DMA_BIT_MASK(39);
289 musb_pdev->dev.dma_mask = &musb_pdev->dev.coherent_dma_mask;
290 device_set_of_node_from_dev(&musb_pdev->dev, dev);
291
292 glue->dev = dev;
293 glue->musb = musb_pdev;
294 glue->clk = clk;
295
296 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
297 if (!pdata) {
298 ret = -ENOMEM;
299 goto err_clk_disable;
300 }
301
302 pdata->config = &mpfs_musb_hdrc_config;
303 pdata->platform_ops = &mpfs_ops;
304
305 pdata->extvbus = device_property_read_bool(dev, "microchip,ext-vbus-drv");
306
307 pdata->mode = usb_get_dr_mode(dev);
308 if (pdata->mode == USB_DR_MODE_UNKNOWN) {
309 dev_info(dev, "No dr_mode property found, defaulting to otg\n");
310 pdata->mode = USB_DR_MODE_OTG;
311 }
312
313 glue->phy = usb_phy_generic_register();
314 if (IS_ERR(glue->phy)) {
315 dev_err(dev, "failed to register usb-phy %ld\n",
316 PTR_ERR(glue->phy));
317 ret = PTR_ERR(glue->phy);
318 goto err_clk_disable;
319 }
320
321 platform_set_drvdata(pdev, glue);
322
323 ret = platform_device_add_resources(musb_pdev, pdev->resource, pdev->num_resources);
324 if (ret) {
325 dev_err(dev, "failed to add resources\n");
326 goto err_clk_disable;
327 }
328
329 ret = platform_device_add_data(musb_pdev, pdata, sizeof(*pdata));
330 if (ret) {
331 dev_err(dev, "failed to add platform_data\n");
332 goto err_clk_disable;
333 }
334
335 ret = platform_device_add(musb_pdev);
336 if (ret) {
337 dev_err(dev, "failed to register musb device\n");
338 goto err_clk_disable;
339 }
340
341 dev_info(&pdev->dev, "Registered MPFS MUSB driver\n");
342 return 0;
343
344 err_clk_disable:
345 clk_disable_unprepare(clk);
346
347 err_phy_release:
348 usb_phy_generic_unregister(glue->phy);
349 platform_device_put(musb_pdev);
350 return ret;
351 }
352
mpfs_remove(struct platform_device * pdev)353 static void mpfs_remove(struct platform_device *pdev)
354 {
355 struct mpfs_glue *glue = platform_get_drvdata(pdev);
356
357 clk_disable_unprepare(glue->clk);
358 platform_device_unregister(glue->musb);
359 usb_phy_generic_unregister(pdev);
360 }
361
362 #ifdef CONFIG_OF
363 static const struct of_device_id mpfs_id_table[] = {
364 { .compatible = "microchip,mpfs-musb" },
365 { }
366 };
367 MODULE_DEVICE_TABLE(of, mpfs_id_table);
368 #endif
369
370 static struct platform_driver mpfs_musb_driver = {
371 .probe = mpfs_probe,
372 .remove_new = mpfs_remove,
373 .driver = {
374 .name = "mpfs-musb",
375 .of_match_table = of_match_ptr(mpfs_id_table)
376 },
377 };
378
379 module_platform_driver(mpfs_musb_driver);
380
381 MODULE_DESCRIPTION("PolarFire SoC MUSB Glue Layer");
382 MODULE_LICENSE("GPL");
383