drivers/usb/gadget/udc/aspeed-vhub/core.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * aspeed-vhub -- Driver for Aspeed SoC "vHub" USB gadget
   4  *
   5  * core.c - Top level support
   6  *
   7  * Copyright 2017 IBM Corporation
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/delay.h>
  19 #include <linux/ioport.h>
  20 #include <linux/slab.h>
  21 #include <linux/errno.h>
  22 #include <linux/list.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/prefetch.h>
  26 #include <linux/clk.h>
  27 #include <linux/usb/gadget.h>
  28 #include <linux/of.h>
  29 #include <linux/of_gpio.h>
  30 #include <linux/regmap.h>
  31 #include <linux/dma-mapping.h>
  32
  33 #include "vhub.h"
  34
  35 void ast_vhub_done(struct ast_vhub_ep *ep, struct ast_vhub_req *req,
  36                    int status)
  37 {
  38         bool internal = req->internal;
  39
  40         EPVDBG(ep, "completing request @%p, status %d\n", req, status);
  41
  42         list_del_init(&req->queue);
  43
  44         if (req->req.status == -EINPROGRESS)
  45                 req->req.status = status;
  46
  47         if (req->req.dma) {
  48                 if (!WARN_ON(!ep->dev))
  49                         usb_gadget_unmap_request(&ep->dev->gadget,
  50                                                  &req->req, ep->epn.is_in);
  51                 req->req.dma = 0;
  52         }
  53
  54         /*
  55          * If this isn't an internal EP0 request, call the core
  56          * to call the gadget completion.
  57          */
  58         if (!internal) {
  59                 spin_unlock(&ep->vhub->lock);
  60                 usb_gadget_giveback_request(&ep->ep, &req->req);
  61                 spin_lock(&ep->vhub->lock);
  62         }
  63 }
  64
  65 void ast_vhub_nuke(struct ast_vhub_ep *ep, int status)
  66 {
  67         struct ast_vhub_req *req;
  68
  69         EPDBG(ep, "Nuking\n");
  70
  71         /* Beware, lock will be dropped & req-acquired by done() */
  72         while (!list_empty(&ep->queue)) {
  73                 req = list_first_entry(&ep->queue, struct ast_vhub_req, queue);
  74                 ast_vhub_done(ep, req, status);
  75         }
  76 }
  77
  78 struct usb_request *ast_vhub_alloc_request(struct usb_ep *u_ep,
  79                                            gfp_t gfp_flags)
  80 {
  81         struct ast_vhub_req *req;
  82
  83         req = kzalloc(sizeof(*req), gfp_flags);
  84         if (!req)
  85                 return NULL;
  86         return &req->req;
  87 }
  88
  89 void ast_vhub_free_request(struct usb_ep *u_ep, struct usb_request *u_req)
  90 {
  91         struct ast_vhub_req *req = to_ast_req(u_req);
  92
  93         kfree(req);
  94 }
  95
  96 static irqreturn_t ast_vhub_irq(int irq, void *data)
  97 {
  98         struct ast_vhub *vhub = data;
  99         irqreturn_t iret = IRQ_NONE;
 100         u32 istat;
 101
 102         /* Stale interrupt while tearing down */
 103         if (!vhub->ep0_bufs)
 104                 return IRQ_NONE;
 105
 106         spin_lock(&vhub->lock);
 107
 108         /* Read and ACK interrupts */
 109         istat = readl(vhub->regs + AST_VHUB_ISR);
 110         if (!istat)
 111                 goto bail;
 112         writel(istat, vhub->regs + AST_VHUB_ISR);
 113         iret = IRQ_HANDLED;
 114
 115         UDCVDBG(vhub, "irq status=%08x, ep_acks=%08x ep_nacks=%08x\n",
 116                istat,
 117                readl(vhub->regs + AST_VHUB_EP_ACK_ISR),
 118                readl(vhub->regs + AST_VHUB_EP_NACK_ISR));
 119
 120         /* Handle generic EPs first */
 121         if (istat & VHUB_IRQ_EP_POOL_ACK_STALL) {
 122                 u32 i, ep_acks = readl(vhub->regs + AST_VHUB_EP_ACK_ISR);
 123                 writel(ep_acks, vhub->regs + AST_VHUB_EP_ACK_ISR);
 124
 125                 for (i = 0; ep_acks && i < AST_VHUB_NUM_GEN_EPs; i++) {
 126                         u32 mask = VHUB_EP_IRQ(i);
 127                         if (ep_acks & mask) {
 128                                 ast_vhub_epn_ack_irq(&vhub->epns[i]);
 129                                 ep_acks &= ~mask;
 130                         }
 131                 }
 132         }
 133
 134         /* Handle device interrupts */
 135         if (istat & (VHUB_IRQ_DEVICE1 |
 136                      VHUB_IRQ_DEVICE2 |
 137                      VHUB_IRQ_DEVICE3 |
 138                      VHUB_IRQ_DEVICE4 |
 139                      VHUB_IRQ_DEVICE5)) {
 140                 if (istat & VHUB_IRQ_DEVICE1)
 141                         ast_vhub_dev_irq(&vhub->ports[0].dev);
 142                 if (istat & VHUB_IRQ_DEVICE2)
 143                         ast_vhub_dev_irq(&vhub->ports[1].dev);
 144                 if (istat & VHUB_IRQ_DEVICE3)
 145                         ast_vhub_dev_irq(&vhub->ports[2].dev);
 146                 if (istat & VHUB_IRQ_DEVICE4)
 147                         ast_vhub_dev_irq(&vhub->ports[3].dev);
 148                 if (istat & VHUB_IRQ_DEVICE5)
 149                         ast_vhub_dev_irq(&vhub->ports[4].dev);
 150         }
 151
 152         /* Handle top-level vHub EP0 interrupts */
 153         if (istat & (VHUB_IRQ_HUB_EP0_OUT_ACK_STALL |
 154                      VHUB_IRQ_HUB_EP0_IN_ACK_STALL |
 155                      VHUB_IRQ_HUB_EP0_SETUP)) {
 156                 if (istat & VHUB_IRQ_HUB_EP0_IN_ACK_STALL)
 157                         ast_vhub_ep0_handle_ack(&vhub->ep0, true);
 158                 if (istat & VHUB_IRQ_HUB_EP0_OUT_ACK_STALL)
 159                         ast_vhub_ep0_handle_ack(&vhub->ep0, false);
 160                 if (istat & VHUB_IRQ_HUB_EP0_SETUP)
 161                         ast_vhub_ep0_handle_setup(&vhub->ep0);
 162         }
 163
 164         /* Various top level bus events */
 165         if (istat & (VHUB_IRQ_BUS_RESUME |
 166                      VHUB_IRQ_BUS_SUSPEND |
 167                      VHUB_IRQ_BUS_RESET)) {
 168                 if (istat & VHUB_IRQ_BUS_RESUME)
 169                         ast_vhub_hub_resume(vhub);
 170                 if (istat & VHUB_IRQ_BUS_SUSPEND)
 171                         ast_vhub_hub_suspend(vhub);
 172                 if (istat & VHUB_IRQ_BUS_RESET)
 173                         ast_vhub_hub_reset(vhub);
 174         }
 175
 176  bail:
 177         spin_unlock(&vhub->lock);
 178         return iret;
 179 }
 180
 181 void ast_vhub_init_hw(struct ast_vhub *vhub)
 182 {
 183         u32 ctrl;
 184
 185         UDCDBG(vhub,"(Re)Starting HW ...\n");
 186
 187         /* Enable PHY */
 188         ctrl = VHUB_CTRL_PHY_CLK |
 189                 VHUB_CTRL_PHY_RESET_DIS;
 190
 191        /*
 192         * We do *NOT* set the VHUB_CTRL_CLK_STOP_SUSPEND bit
 193         * to stop the logic clock during suspend because
 194         * it causes the registers to become inaccessible and
 195         * we haven't yet figured out a good wayt to bring the
 196         * controller back into life to issue a wakeup.
 197         */
 198
 199         /*
 200          * Set some ISO & split control bits according to Aspeed
 201          * recommendation
 202          *
 203          * VHUB_CTRL_ISO_RSP_CTRL: When set tells the HW to respond
 204          * with 0 bytes data packet to ISO IN endpoints when no data
 205          * is available.
 206          *
 207          * VHUB_CTRL_SPLIT_IN: This makes a SOF complete a split IN
 208          * transaction.
 209          */
 210         ctrl |= VHUB_CTRL_ISO_RSP_CTRL | VHUB_CTRL_SPLIT_IN;
 211         writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 212         udelay(1);
 213
 214         /* Set descriptor ring size */
 215         if (AST_VHUB_DESCS_COUNT == 256) {
 216                 ctrl |= VHUB_CTRL_LONG_DESC;
 217                 writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 218         } else {
 219                 BUILD_BUG_ON(AST_VHUB_DESCS_COUNT != 32);
 220         }
 221
 222         /* Reset all devices */
 223         writel(VHUB_SW_RESET_ALL, vhub->regs + AST_VHUB_SW_RESET);
 224         udelay(1);
 225         writel(0, vhub->regs + AST_VHUB_SW_RESET);
 226
 227         /* Disable and cleanup EP ACK/NACK interrupts */
 228         writel(0, vhub->regs + AST_VHUB_EP_ACK_IER);
 229         writel(0, vhub->regs + AST_VHUB_EP_NACK_IER);
 230         writel(VHUB_EP_IRQ_ALL, vhub->regs + AST_VHUB_EP_ACK_ISR);
 231         writel(VHUB_EP_IRQ_ALL, vhub->regs + AST_VHUB_EP_NACK_ISR);
 232
 233         /* Default settings for EP0, enable HW hub EP1 */
 234         writel(0, vhub->regs + AST_VHUB_EP0_CTRL);
 235         writel(VHUB_EP1_CTRL_RESET_TOGGLE |
 236                VHUB_EP1_CTRL_ENABLE,
 237                vhub->regs + AST_VHUB_EP1_CTRL);
 238         writel(0, vhub->regs + AST_VHUB_EP1_STS_CHG);
 239
 240         /* Configure EP0 DMA buffer */
 241         writel(vhub->ep0.buf_dma, vhub->regs + AST_VHUB_EP0_DATA);
 242
 243         /* Clear address */
 244         writel(0, vhub->regs + AST_VHUB_CONF);
 245
 246         /* Pullup hub (activate on host) */
 247         if (vhub->force_usb1)
 248                 ctrl |= VHUB_CTRL_FULL_SPEED_ONLY;
 249
 250         ctrl |= VHUB_CTRL_UPSTREAM_CONNECT;
 251         writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 252
 253         /* Enable some interrupts */
 254         writel(VHUB_IRQ_HUB_EP0_IN_ACK_STALL |
 255                VHUB_IRQ_HUB_EP0_OUT_ACK_STALL |
 256                VHUB_IRQ_HUB_EP0_SETUP |
 257                VHUB_IRQ_EP_POOL_ACK_STALL |
 258                VHUB_IRQ_BUS_RESUME |
 259                VHUB_IRQ_BUS_SUSPEND |
 260                VHUB_IRQ_BUS_RESET,
 261                vhub->regs + AST_VHUB_IER);
 262 }
 263
 264 static int ast_vhub_remove(struct platform_device *pdev)
 265 {
 266         struct ast_vhub *vhub = platform_get_drvdata(pdev);
 267         unsigned long flags;
 268         int i;
 269
 270         if (!vhub || !vhub->regs)
 271                 return 0;
 272
 273         /* Remove devices */
 274         for (i = 0; i < AST_VHUB_NUM_PORTS; i++)
 275                 ast_vhub_del_dev(&vhub->ports[i].dev);
 276
 277         spin_lock_irqsave(&vhub->lock, flags);
 278
 279         /* Mask & ack all interrupts  */
 280         writel(0, vhub->regs + AST_VHUB_IER);
 281         writel(VHUB_IRQ_ACK_ALL, vhub->regs + AST_VHUB_ISR);
 282
 283         /* Pull device, leave PHY enabled */
 284         writel(VHUB_CTRL_PHY_CLK |
 285                VHUB_CTRL_PHY_RESET_DIS,
 286                vhub->regs + AST_VHUB_CTRL);
 287
 288         if (vhub->clk)
 289                 clk_disable_unprepare(vhub->clk);
 290
 291         spin_unlock_irqrestore(&vhub->lock, flags);
 292
 293         if (vhub->ep0_bufs)
 294                 dma_free_coherent(&pdev->dev,
 295                                   AST_VHUB_EP0_MAX_PACKET *
 296                                   (AST_VHUB_NUM_PORTS + 1),
 297                                   vhub->ep0_bufs,
 298                                   vhub->ep0_bufs_dma);
 299         vhub->ep0_bufs = NULL;
 300
 301         return 0;
 302 }
 303
 304 static int ast_vhub_probe(struct platform_device *pdev)
 305 {
 306         enum usb_device_speed max_speed;
 307         struct ast_vhub *vhub;
 308         struct resource *res;
 309         int i, rc = 0;
 310
 311         vhub = devm_kzalloc(&pdev->dev, sizeof(*vhub), GFP_KERNEL);
 312         if (!vhub)
 313                 return -ENOMEM;
 314
 315         spin_lock_init(&vhub->lock);
 316         vhub->pdev = pdev;
 317
 318         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 319         vhub->regs = devm_ioremap_resource(&pdev->dev, res);
 320         if (IS_ERR(vhub->regs)) {
 321                 dev_err(&pdev->dev, "Failed to map resources\n");
 322                 return PTR_ERR(vhub->regs);
 323         }
 324         UDCDBG(vhub, "vHub@%pR mapped @%p\n", res, vhub->regs);
 325
 326         platform_set_drvdata(pdev, vhub);
 327
 328         vhub->clk = devm_clk_get(&pdev->dev, NULL);
 329         if (IS_ERR(vhub->clk)) {
 330                 rc = PTR_ERR(vhub->clk);
 331                 goto err;
 332         }
 333         rc = clk_prepare_enable(vhub->clk);
 334         if (rc) {
 335                 dev_err(&pdev->dev, "Error couldn't enable clock (%d)\n", rc);
 336                 goto err;
 337         }
 338
 339         /* Check if we need to limit the HW to USB1 */
 340         max_speed = usb_get_maximum_speed(&pdev->dev);
 341         if (max_speed != USB_SPEED_UNKNOWN && max_speed < USB_SPEED_HIGH)
 342                 vhub->force_usb1 = true;
 343
 344         /* Mask & ack all interrupts before installing the handler */
 345         writel(0, vhub->regs + AST_VHUB_IER);
 346         writel(VHUB_IRQ_ACK_ALL, vhub->regs + AST_VHUB_ISR);
 347
 348         /* Find interrupt and install handler */
 349         vhub->irq = platform_get_irq(pdev, 0);
 350         if (vhub->irq < 0) {
 351                 dev_err(&pdev->dev, "Failed to get interrupt\n");
 352                 rc = vhub->irq;
 353                 goto err;
 354         }
 355         rc = devm_request_irq(&pdev->dev, vhub->irq, ast_vhub_irq, 0,
 356                               KBUILD_MODNAME, vhub);
 357         if (rc) {
 358                 dev_err(&pdev->dev, "Failed to request interrupt\n");
 359                 goto err;
 360         }
 361
 362         /*
 363          * Allocate DMA buffers for all EP0s in one chunk,
 364          * one per port and one for the vHub itself
 365          */
 366         vhub->ep0_bufs = dma_alloc_coherent(&pdev->dev,
 367                                             AST_VHUB_EP0_MAX_PACKET *
 368                                             (AST_VHUB_NUM_PORTS + 1),
 369                                             &vhub->ep0_bufs_dma, GFP_KERNEL);
 370         if (!vhub->ep0_bufs) {
 371                 dev_err(&pdev->dev, "Failed to allocate EP0 DMA buffers\n");
 372                 rc = -ENOMEM;
 373                 goto err;
 374         }
 375         UDCVDBG(vhub, "EP0 DMA buffers @%p (DMA 0x%08x)\n",
 376                 vhub->ep0_bufs, (u32)vhub->ep0_bufs_dma);
 377
 378         /* Init vHub EP0 */
 379         ast_vhub_init_ep0(vhub, &vhub->ep0, NULL);
 380
 381         /* Init devices */
 382         for (i = 0; i < AST_VHUB_NUM_PORTS && rc == 0; i++)
 383                 rc = ast_vhub_init_dev(vhub, i);
 384         if (rc)
 385                 goto err;
 386
 387         /* Init hub emulation */
 388         ast_vhub_init_hub(vhub);
 389
 390         /* Initialize HW */
 391         ast_vhub_init_hw(vhub);
 392
 393         dev_info(&pdev->dev, "Initialized virtual hub in USB%d mode\n",
 394                  vhub->force_usb1 ? 1 : 2);
 395
 396         return 0;
 397  err:
 398         ast_vhub_remove(pdev);
 399         return rc;
 400 }
 401
 402 static const struct of_device_id ast_vhub_dt_ids[] = {
 403         {
 404                 .compatible = "aspeed,ast2400-usb-vhub",
 405         },
 406         {
 407                 .compatible = "aspeed,ast2500-usb-vhub",
 408         },
 409         { }
 410 };
 411 MODULE_DEVICE_TABLE(of, ast_vhub_dt_ids);
 412
 413 static struct platform_driver ast_vhub_driver = {
 414         .probe          = ast_vhub_probe,
 415         .remove         = ast_vhub_remove,
 416         .driver         = {
 417                 .name   = KBUILD_MODNAME,
 418                 .of_match_table = ast_vhub_dt_ids,
 419         },
 420 };
 421 module_platform_driver(ast_vhub_driver);
 422
 423 MODULE_DESCRIPTION("Aspeed vHub udc driver");
 424 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 425 MODULE_LICENSE("GPL");