LXR linux/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
  35void 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
  65void ast_vhub_nuke(struct ast_vhub_ep *ep, int status)
  66{
  67        struct ast_vhub_req *req;
  68        int count = 0;
  69
  70        /* Beware, lock will be dropped & req-acquired by done() */
  71        while (!list_empty(&ep->queue)) {
  72                req = list_first_entry(&ep->queue, struct ast_vhub_req, queue);
  73                ast_vhub_done(ep, req, status);
  74                count++;
  75        }
  76        if (count)
  77                EPDBG(ep, "Nuked %d request(s)\n", count);
  78}
  79
  80struct usb_request *ast_vhub_alloc_request(struct usb_ep *u_ep,
  81                                           gfp_t gfp_flags)
  82{
  83        struct ast_vhub_req *req;
  84
  85        req = kzalloc(sizeof(*req), gfp_flags);
  86        if (!req)
  87                return NULL;
  88        return &req->req;
  89}
  90
  91void ast_vhub_free_request(struct usb_ep *u_ep, struct usb_request *u_req)
  92{
  93        struct ast_vhub_req *req = to_ast_req(u_req);
  94
  95        kfree(req);
  96}
  97
  98static irqreturn_t ast_vhub_irq(int irq, void *data)
  99{
 100        struct ast_vhub *vhub = data;
 101        irqreturn_t iret = IRQ_NONE;
 102        u32 i, istat;
 103
 104        /* Stale interrupt while tearing down */
 105        if (!vhub->ep0_bufs)
 106                return IRQ_NONE;
 107
 108        spin_lock(&vhub->lock);
 109
 110        /* Read and ACK interrupts */
 111        istat = readl(vhub->regs + AST_VHUB_ISR);
 112        if (!istat)
 113                goto bail;
 114        writel(istat, vhub->regs + AST_VHUB_ISR);
 115        iret = IRQ_HANDLED;
 116
 117        UDCVDBG(vhub, "irq status=%08x, ep_acks=%08x ep_nacks=%08x\n",
 118               istat,
 119               readl(vhub->regs + AST_VHUB_EP_ACK_ISR),
 120               readl(vhub->regs + AST_VHUB_EP_NACK_ISR));
 121
 122        /* Handle generic EPs first */
 123        if (istat & VHUB_IRQ_EP_POOL_ACK_STALL) {
 124                u32 ep_acks = readl(vhub->regs + AST_VHUB_EP_ACK_ISR);
 125                writel(ep_acks, vhub->regs + AST_VHUB_EP_ACK_ISR);
 126
 127                for (i = 0; ep_acks && i < vhub->max_epns; i++) {
 128                        u32 mask = VHUB_EP_IRQ(i);
 129                        if (ep_acks & mask) {
 130                                ast_vhub_epn_ack_irq(&vhub->epns[i]);
 131                                ep_acks &= ~mask;
 132                        }
 133                }
 134        }
 135
 136        /* Handle device interrupts */
 137        if (istat & vhub->port_irq_mask) {
 138                for (i = 0; i < vhub->max_ports; i++) {
 139                        if (istat & VHUB_DEV_IRQ(i))
 140                                ast_vhub_dev_irq(&vhub->ports[i].dev);
 141                }
 142        }
 143
 144        /* Handle top-level vHub EP0 interrupts */
 145        if (istat & (VHUB_IRQ_HUB_EP0_OUT_ACK_STALL |
 146                     VHUB_IRQ_HUB_EP0_IN_ACK_STALL |
 147                     VHUB_IRQ_HUB_EP0_SETUP)) {
 148                if (istat & VHUB_IRQ_HUB_EP0_IN_ACK_STALL)
 149                        ast_vhub_ep0_handle_ack(&vhub->ep0, true);
 150                if (istat & VHUB_IRQ_HUB_EP0_OUT_ACK_STALL)
 151                        ast_vhub_ep0_handle_ack(&vhub->ep0, false);
 152                if (istat & VHUB_IRQ_HUB_EP0_SETUP)
 153                        ast_vhub_ep0_handle_setup(&vhub->ep0);
 154        }
 155
 156        /* Various top level bus events */
 157        if (istat & (VHUB_IRQ_BUS_RESUME |
 158                     VHUB_IRQ_BUS_SUSPEND |
 159                     VHUB_IRQ_BUS_RESET)) {
 160                if (istat & VHUB_IRQ_BUS_RESUME)
 161                        ast_vhub_hub_resume(vhub);
 162                if (istat & VHUB_IRQ_BUS_SUSPEND)
 163                        ast_vhub_hub_suspend(vhub);
 164                if (istat & VHUB_IRQ_BUS_RESET)
 165                        ast_vhub_hub_reset(vhub);
 166        }
 167
 168 bail:
 169        spin_unlock(&vhub->lock);
 170        return iret;
 171}
 172
 173void ast_vhub_init_hw(struct ast_vhub *vhub)
 174{
 175        u32 ctrl, port_mask, epn_mask;
 176
 177        UDCDBG(vhub,"(Re)Starting HW ...\n");
 178
 179        /* Enable PHY */
 180        ctrl = VHUB_CTRL_PHY_CLK |
 181                VHUB_CTRL_PHY_RESET_DIS;
 182
 183       /*
 184        * We do *NOT* set the VHUB_CTRL_CLK_STOP_SUSPEND bit
 185        * to stop the logic clock during suspend because
 186        * it causes the registers to become inaccessible and
 187        * we haven't yet figured out a good wayt to bring the
 188        * controller back into life to issue a wakeup.
 189        */
 190
 191        /*
 192         * Set some ISO & split control bits according to Aspeed
 193         * recommendation
 194         *
 195         * VHUB_CTRL_ISO_RSP_CTRL: When set tells the HW to respond
 196         * with 0 bytes data packet to ISO IN endpoints when no data
 197         * is available.
 198         *
 199         * VHUB_CTRL_SPLIT_IN: This makes a SOF complete a split IN
 200         * transaction.
 201         */
 202        ctrl |= VHUB_CTRL_ISO_RSP_CTRL | VHUB_CTRL_SPLIT_IN;
 203        writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 204        udelay(1);
 205
 206        /* Set descriptor ring size */
 207        if (AST_VHUB_DESCS_COUNT == 256) {
 208                ctrl |= VHUB_CTRL_LONG_DESC;
 209                writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 210        } else {
 211                BUILD_BUG_ON(AST_VHUB_DESCS_COUNT != 32);
 212        }
 213
 214        /* Reset all devices */
 215        port_mask = GENMASK(vhub->max_ports, 1);
 216        writel(VHUB_SW_RESET_ROOT_HUB |
 217               VHUB_SW_RESET_DMA_CONTROLLER |
 218               VHUB_SW_RESET_EP_POOL |
 219               port_mask, vhub->regs + AST_VHUB_SW_RESET);
 220        udelay(1);
 221        writel(0, vhub->regs + AST_VHUB_SW_RESET);
 222
 223        /* Disable and cleanup EP ACK/NACK interrupts */
 224        epn_mask = GENMASK(vhub->max_epns - 1, 0);
 225        writel(0, vhub->regs + AST_VHUB_EP_ACK_IER);
 226        writel(0, vhub->regs + AST_VHUB_EP_NACK_IER);
 227        writel(epn_mask, vhub->regs + AST_VHUB_EP_ACK_ISR);
 228        writel(epn_mask, vhub->regs + AST_VHUB_EP_NACK_ISR);
 229
 230        /* Default settings for EP0, enable HW hub EP1 */
 231        writel(0, vhub->regs + AST_VHUB_EP0_CTRL);
 232        writel(VHUB_EP1_CTRL_RESET_TOGGLE |
 233               VHUB_EP1_CTRL_ENABLE,
 234               vhub->regs + AST_VHUB_EP1_CTRL);
 235        writel(0, vhub->regs + AST_VHUB_EP1_STS_CHG);
 236
 237        /* Configure EP0 DMA buffer */
 238        writel(vhub->ep0.buf_dma, vhub->regs + AST_VHUB_EP0_DATA);
 239
 240        /* Clear address */
 241        writel(0, vhub->regs + AST_VHUB_CONF);
 242
 243        /* Pullup hub (activate on host) */
 244        if (vhub->force_usb1)
 245                ctrl |= VHUB_CTRL_FULL_SPEED_ONLY;
 246
 247        ctrl |= VHUB_CTRL_UPSTREAM_CONNECT;
 248        writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 249
 250        /* Enable some interrupts */
 251        writel(VHUB_IRQ_HUB_EP0_IN_ACK_STALL |
 252               VHUB_IRQ_HUB_EP0_OUT_ACK_STALL |
 253               VHUB_IRQ_HUB_EP0_SETUP |
 254               VHUB_IRQ_EP_POOL_ACK_STALL |
 255               VHUB_IRQ_BUS_RESUME |
 256               VHUB_IRQ_BUS_SUSPEND |
 257               VHUB_IRQ_BUS_RESET,
 258               vhub->regs + AST_VHUB_IER);
 259}
 260
 261static int ast_vhub_remove(struct platform_device *pdev)
 262{
 263        struct ast_vhub *vhub = platform_get_drvdata(pdev);
 264        unsigned long flags;
 265        int i;
 266
 267        if (!vhub || !vhub->regs)
 268                return 0;
 269
 270        /* Remove devices */
 271        for (i = 0; i < vhub->max_ports; i++)
 272                ast_vhub_del_dev(&vhub->ports[i].dev);
 273
 274        spin_lock_irqsave(&vhub->lock, flags);
 275
 276        /* Mask & ack all interrupts  */
 277        writel(0, vhub->regs + AST_VHUB_IER);
 278        writel(VHUB_IRQ_ACK_ALL, vhub->regs + AST_VHUB_ISR);
 279
 280        /* Pull device, leave PHY enabled */
 281        writel(VHUB_CTRL_PHY_CLK |
 282               VHUB_CTRL_PHY_RESET_DIS,
 283               vhub->regs + AST_VHUB_CTRL);
 284
 285        if (vhub->clk)
 286                clk_disable_unprepare(vhub->clk);
 287
 288        spin_unlock_irqrestore(&vhub->lock, flags);
 289
 290        if (vhub->ep0_bufs)
 291                dma_free_coherent(&pdev->dev,
 292                                  AST_VHUB_EP0_MAX_PACKET *
 293                                  (vhub->max_ports + 1),
 294                                  vhub->ep0_bufs,
 295                                  vhub->ep0_bufs_dma);
 296        vhub->ep0_bufs = NULL;
 297
 298        return 0;
 299}
 300
 301static int ast_vhub_probe(struct platform_device *pdev)
 302{
 303        enum usb_device_speed max_speed;
 304        struct ast_vhub *vhub;
 305        struct resource *res;
 306        int i, rc = 0;
 307        const struct device_node *np = pdev->dev.of_node;
 308
 309        vhub = devm_kzalloc(&pdev->dev, sizeof(*vhub), GFP_KERNEL);
 310        if (!vhub)
 311                return -ENOMEM;
 312
 313        rc = of_property_read_u32(np, "aspeed,vhub-downstream-ports",
 314                                  &vhub->max_ports);
 315        if (rc < 0)
 316                vhub->max_ports = AST_VHUB_NUM_PORTS;
 317
 318        vhub->ports = devm_kcalloc(&pdev->dev, vhub->max_ports,
 319                                   sizeof(*vhub->ports), GFP_KERNEL);
 320        if (!vhub->ports)
 321                return -ENOMEM;
 322
 323        rc = of_property_read_u32(np, "aspeed,vhub-generic-endpoints",
 324                                  &vhub->max_epns);
 325        if (rc < 0)
 326                vhub->max_epns = AST_VHUB_NUM_GEN_EPs;
 327
 328        vhub->epns = devm_kcalloc(&pdev->dev, vhub->max_epns,
 329                                  sizeof(*vhub->epns), GFP_KERNEL);
 330        if (!vhub->epns)
 331                return -ENOMEM;
 332
 333        spin_lock_init(&vhub->lock);
 334        vhub->pdev = pdev;
 335        vhub->port_irq_mask = GENMASK(VHUB_IRQ_DEV1_BIT + vhub->max_ports - 1,
 336                                      VHUB_IRQ_DEV1_BIT);
 337
 338        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 339        vhub->regs = devm_ioremap_resource(&pdev->dev, res);
 340        if (IS_ERR(vhub->regs)) {
 341                dev_err(&pdev->dev, "Failed to map resources\n");
 342                return PTR_ERR(vhub->regs);
 343        }
 344        UDCDBG(vhub, "vHub@%pR mapped @%p\n", res, vhub->regs);
 345
 346        platform_set_drvdata(pdev, vhub);
 347
 348        vhub->clk = devm_clk_get(&pdev->dev, NULL);
 349        if (IS_ERR(vhub->clk)) {
 350                rc = PTR_ERR(vhub->clk);
 351                goto err;
 352        }
 353        rc = clk_prepare_enable(vhub->clk);
 354        if (rc) {
 355                dev_err(&pdev->dev, "Error couldn't enable clock (%d)\n", rc);
 356                goto err;
 357        }
 358
 359        /* Check if we need to limit the HW to USB1 */
 360        max_speed = usb_get_maximum_speed(&pdev->dev);
 361        if (max_speed != USB_SPEED_UNKNOWN && max_speed < USB_SPEED_HIGH)
 362                vhub->force_usb1 = true;
 363
 364        /* Mask & ack all interrupts before installing the handler */
 365        writel(0, vhub->regs + AST_VHUB_IER);
 366        writel(VHUB_IRQ_ACK_ALL, vhub->regs + AST_VHUB_ISR);
 367
 368        /* Find interrupt and install handler */
 369        vhub->irq = platform_get_irq(pdev, 0);
 370        if (vhub->irq < 0) {
 371                rc = vhub->irq;
 372                goto err;
 373        }
 374        rc = devm_request_irq(&pdev->dev, vhub->irq, ast_vhub_irq, 0,
 375                              KBUILD_MODNAME, vhub);
 376        if (rc) {
 377                dev_err(&pdev->dev, "Failed to request interrupt\n");
 378                goto err;
 379        }
 380
 381        /*
 382         * Allocate DMA buffers for all EP0s in one chunk,
 383         * one per port and one for the vHub itself
 384         */
 385        vhub->ep0_bufs = dma_alloc_coherent(&pdev->dev,
 386                                            AST_VHUB_EP0_MAX_PACKET *
 387                                            (vhub->max_ports + 1),
 388                                            &vhub->ep0_bufs_dma, GFP_KERNEL);
 389        if (!vhub->ep0_bufs) {
 390                dev_err(&pdev->dev, "Failed to allocate EP0 DMA buffers\n");
 391                rc = -ENOMEM;
 392                goto err;
 393        }
 394        UDCVDBG(vhub, "EP0 DMA buffers @%p (DMA 0x%08x)\n",
 395                vhub->ep0_bufs, (u32)vhub->ep0_bufs_dma);
 396
 397        /* Init vHub EP0 */
 398        ast_vhub_init_ep0(vhub, &vhub->ep0, NULL);
 399
 400        /* Init devices */
 401        for (i = 0; i < vhub->max_ports && rc == 0; i++)
 402                rc = ast_vhub_init_dev(vhub, i);
 403        if (rc)
 404                goto err;
 405
 406        /* Init hub emulation */
 407        rc = ast_vhub_init_hub(vhub);
 408        if (rc)
 409                goto err;
 410
 411        /* Initialize HW */
 412        ast_vhub_init_hw(vhub);
 413
 414        dev_info(&pdev->dev, "Initialized virtual hub in USB%d mode\n",
 415                 vhub->force_usb1 ? 1 : 2);
 416
 417        return 0;
 418 err:
 419        ast_vhub_remove(pdev);
 420        return rc;
 421}
 422
 423static const struct of_device_id ast_vhub_dt_ids[] = {
 424        {
 425                .compatible = "aspeed,ast2400-usb-vhub",
 426        },
 427        {
 428                .compatible = "aspeed,ast2500-usb-vhub",
 429        },
 430        {
 431                .compatible = "aspeed,ast2600-usb-vhub",
 432        },
 433        { }
 434};
 435MODULE_DEVICE_TABLE(of, ast_vhub_dt_ids);
 436
 437static struct platform_driver ast_vhub_driver = {
 438        .probe          = ast_vhub_probe,
 439        .remove         = ast_vhub_remove,
 440        .driver         = {
 441                .name   = KBUILD_MODNAME,
 442                .of_match_table = ast_vhub_dt_ids,
 443        },
 444};
 445module_platform_driver(ast_vhub_driver);
 446
 447MODULE_DESCRIPTION("Aspeed vHub udc driver");
 448MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 449MODULE_LICENSE("GPL");
 450