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
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/platform_device.h>
  13#include <linux/delay.h>
  14#include <linux/ioport.h>
  15#include <linux/slab.h>
  16#include <linux/errno.h>
  17#include <linux/list.h>
  18#include <linux/interrupt.h>
  19#include <linux/proc_fs.h>
  20#include <linux/prefetch.h>
  21#include <linux/clk.h>
  22#include <linux/usb/gadget.h>
  23#include <linux/of.h>
  24#include <linux/of_gpio.h>
  25#include <linux/regmap.h>
  26#include <linux/dma-mapping.h>
  27
  28#include "vhub.h"
  29
  30void ast_vhub_done(struct ast_vhub_ep *ep, struct ast_vhub_req *req,
  31                   int status)
  32{
  33        bool internal = req->internal;
  34        struct ast_vhub *vhub = ep->vhub;
  35
  36        EPVDBG(ep, "completing request @%p, status %d\n", req, status);
  37
  38        list_del_init(&req->queue);
  39
  40        if (req->req.status == -EINPROGRESS)
  41                req->req.status = status;
  42
  43        if (req->req.dma) {
  44                if (!WARN_ON(!ep->dev))
  45                        usb_gadget_unmap_request_by_dev(&vhub->pdev->dev,
  46                                                 &req->req, ep->epn.is_in);
  47                req->req.dma = 0;
  48        }
  49
  50        /*
  51         * If this isn't an internal EP0 request, call the core
  52         * to call the gadget completion.
  53         */
  54        if (!internal) {
  55                spin_unlock(&ep->vhub->lock);
  56                usb_gadget_giveback_request(&ep->ep, &req->req);
  57                spin_lock(&ep->vhub->lock);
  58        }
  59}
  60
  61void ast_vhub_nuke(struct ast_vhub_ep *ep, int status)
  62{
  63        struct ast_vhub_req *req;
  64        int count = 0;
  65
  66        /* Beware, lock will be dropped & req-acquired by done() */
  67        while (!list_empty(&ep->queue)) {
  68                req = list_first_entry(&ep->queue, struct ast_vhub_req, queue);
  69                ast_vhub_done(ep, req, status);
  70                count++;
  71        }
  72        if (count)
  73                EPDBG(ep, "Nuked %d request(s)\n", count);
  74}
  75
  76struct usb_request *ast_vhub_alloc_request(struct usb_ep *u_ep,
  77                                           gfp_t gfp_flags)
  78{
  79        struct ast_vhub_req *req;
  80
  81        req = kzalloc(sizeof(*req), gfp_flags);
  82        if (!req)
  83                return NULL;
  84        return &req->req;
  85}
  86
  87void ast_vhub_free_request(struct usb_ep *u_ep, struct usb_request *u_req)
  88{
  89        struct ast_vhub_req *req = to_ast_req(u_req);
  90
  91        kfree(req);
  92}
  93
  94static irqreturn_t ast_vhub_irq(int irq, void *data)
  95{
  96        struct ast_vhub *vhub = data;
  97        irqreturn_t iret = IRQ_NONE;
  98        u32 i, istat;
  99
 100        /* Stale interrupt while tearing down */
 101        if (!vhub->ep0_bufs)
 102                return IRQ_NONE;
 103
 104        spin_lock(&vhub->lock);
 105
 106        /* Read and ACK interrupts */
 107        istat = readl(vhub->regs + AST_VHUB_ISR);
 108        if (!istat)
 109                goto bail;
 110        writel(istat, vhub->regs + AST_VHUB_ISR);
 111        iret = IRQ_HANDLED;
 112
 113        UDCVDBG(vhub, "irq status=%08x, ep_acks=%08x ep_nacks=%08x\n",
 114               istat,
 115               readl(vhub->regs + AST_VHUB_EP_ACK_ISR),
 116               readl(vhub->regs + AST_VHUB_EP_NACK_ISR));
 117
 118        /* Handle generic EPs first */
 119        if (istat & VHUB_IRQ_EP_POOL_ACK_STALL) {
 120                u32 ep_acks = readl(vhub->regs + AST_VHUB_EP_ACK_ISR);
 121                writel(ep_acks, vhub->regs + AST_VHUB_EP_ACK_ISR);
 122
 123                for (i = 0; ep_acks && i < vhub->max_epns; i++) {
 124                        u32 mask = VHUB_EP_IRQ(i);
 125                        if (ep_acks & mask) {
 126                                ast_vhub_epn_ack_irq(&vhub->epns[i]);
 127                                ep_acks &= ~mask;
 128                        }
 129                }
 130        }
 131
 132        /* Handle device interrupts */
 133        if (istat & vhub->port_irq_mask) {
 134                for (i = 0; i < vhub->max_ports; i++) {
 135                        if (istat & VHUB_DEV_IRQ(i))
 136                                ast_vhub_dev_irq(&vhub->ports[i].dev);
 137                }
 138        }
 139
 140        /* Handle top-level vHub EP0 interrupts */
 141        if (istat & (VHUB_IRQ_HUB_EP0_OUT_ACK_STALL |
 142                     VHUB_IRQ_HUB_EP0_IN_ACK_STALL |
 143                     VHUB_IRQ_HUB_EP0_SETUP)) {
 144                if (istat & VHUB_IRQ_HUB_EP0_IN_ACK_STALL)
 145                        ast_vhub_ep0_handle_ack(&vhub->ep0, true);
 146                if (istat & VHUB_IRQ_HUB_EP0_OUT_ACK_STALL)
 147                        ast_vhub_ep0_handle_ack(&vhub->ep0, false);
 148                if (istat & VHUB_IRQ_HUB_EP0_SETUP)
 149                        ast_vhub_ep0_handle_setup(&vhub->ep0);
 150        }
 151
 152        /* Various top level bus events */
 153        if (istat & (VHUB_IRQ_BUS_RESUME |
 154                     VHUB_IRQ_BUS_SUSPEND |
 155                     VHUB_IRQ_BUS_RESET)) {
 156                if (istat & VHUB_IRQ_BUS_RESUME)
 157                        ast_vhub_hub_resume(vhub);
 158                if (istat & VHUB_IRQ_BUS_SUSPEND)
 159                        ast_vhub_hub_suspend(vhub);
 160                if (istat & VHUB_IRQ_BUS_RESET)
 161                        ast_vhub_hub_reset(vhub);
 162        }
 163
 164 bail:
 165        spin_unlock(&vhub->lock);
 166        return iret;
 167}
 168
 169void ast_vhub_init_hw(struct ast_vhub *vhub)
 170{
 171        u32 ctrl, port_mask, epn_mask;
 172
 173        UDCDBG(vhub,"(Re)Starting HW ...\n");
 174
 175        /* Enable PHY */
 176        ctrl = VHUB_CTRL_PHY_CLK |
 177                VHUB_CTRL_PHY_RESET_DIS;
 178
 179       /*
 180        * We do *NOT* set the VHUB_CTRL_CLK_STOP_SUSPEND bit
 181        * to stop the logic clock during suspend because
 182        * it causes the registers to become inaccessible and
 183        * we haven't yet figured out a good wayt to bring the
 184        * controller back into life to issue a wakeup.
 185        */
 186
 187        /*
 188         * Set some ISO & split control bits according to Aspeed
 189         * recommendation
 190         *
 191         * VHUB_CTRL_ISO_RSP_CTRL: When set tells the HW to respond
 192         * with 0 bytes data packet to ISO IN endpoints when no data
 193         * is available.
 194         *
 195         * VHUB_CTRL_SPLIT_IN: This makes a SOF complete a split IN
 196         * transaction.
 197         */
 198        ctrl |= VHUB_CTRL_ISO_RSP_CTRL | VHUB_CTRL_SPLIT_IN;
 199        writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 200        udelay(1);
 201
 202        /* Set descriptor ring size */
 203        if (AST_VHUB_DESCS_COUNT == 256) {
 204                ctrl |= VHUB_CTRL_LONG_DESC;
 205                writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 206        } else {
 207                BUILD_BUG_ON(AST_VHUB_DESCS_COUNT != 32);
 208        }
 209
 210        /* Reset all devices */
 211        port_mask = GENMASK(vhub->max_ports, 1);
 212        writel(VHUB_SW_RESET_ROOT_HUB |
 213               VHUB_SW_RESET_DMA_CONTROLLER |
 214               VHUB_SW_RESET_EP_POOL |
 215               port_mask, vhub->regs + AST_VHUB_SW_RESET);
 216        udelay(1);
 217        writel(0, vhub->regs + AST_VHUB_SW_RESET);
 218
 219        /* Disable and cleanup EP ACK/NACK interrupts */
 220        epn_mask = GENMASK(vhub->max_epns - 1, 0);
 221        writel(0, vhub->regs + AST_VHUB_EP_ACK_IER);
 222        writel(0, vhub->regs + AST_VHUB_EP_NACK_IER);
 223        writel(epn_mask, vhub->regs + AST_VHUB_EP_ACK_ISR);
 224        writel(epn_mask, vhub->regs + AST_VHUB_EP_NACK_ISR);
 225
 226        /* Default settings for EP0, enable HW hub EP1 */
 227        writel(0, vhub->regs + AST_VHUB_EP0_CTRL);
 228        writel(VHUB_EP1_CTRL_RESET_TOGGLE |
 229               VHUB_EP1_CTRL_ENABLE,
 230               vhub->regs + AST_VHUB_EP1_CTRL);
 231        writel(0, vhub->regs + AST_VHUB_EP1_STS_CHG);
 232
 233        /* Configure EP0 DMA buffer */
 234        writel(vhub->ep0.buf_dma, vhub->regs + AST_VHUB_EP0_DATA);
 235
 236        /* Clear address */
 237        writel(0, vhub->regs + AST_VHUB_CONF);
 238
 239        /* Pullup hub (activate on host) */
 240        if (vhub->force_usb1)
 241                ctrl |= VHUB_CTRL_FULL_SPEED_ONLY;
 242
 243        ctrl |= VHUB_CTRL_UPSTREAM_CONNECT;
 244        writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 245
 246        /* Enable some interrupts */
 247        writel(VHUB_IRQ_HUB_EP0_IN_ACK_STALL |
 248               VHUB_IRQ_HUB_EP0_OUT_ACK_STALL |
 249               VHUB_IRQ_HUB_EP0_SETUP |
 250               VHUB_IRQ_EP_POOL_ACK_STALL |
 251               VHUB_IRQ_BUS_RESUME |
 252               VHUB_IRQ_BUS_SUSPEND |
 253               VHUB_IRQ_BUS_RESET,
 254               vhub->regs + AST_VHUB_IER);
 255}
 256
 257static int ast_vhub_remove(struct platform_device *pdev)
 258{
 259        struct ast_vhub *vhub = platform_get_drvdata(pdev);
 260        unsigned long flags;
 261        int i;
 262
 263        if (!vhub || !vhub->regs)
 264                return 0;
 265
 266        /* Remove devices */
 267        for (i = 0; i < vhub->max_ports; i++)
 268                ast_vhub_del_dev(&vhub->ports[i].dev);
 269
 270        spin_lock_irqsave(&vhub->lock, flags);
 271
 272        /* Mask & ack all interrupts  */
 273        writel(0, vhub->regs + AST_VHUB_IER);
 274        writel(VHUB_IRQ_ACK_ALL, vhub->regs + AST_VHUB_ISR);
 275
 276        /* Pull device, leave PHY enabled */
 277        writel(VHUB_CTRL_PHY_CLK |
 278               VHUB_CTRL_PHY_RESET_DIS,
 279               vhub->regs + AST_VHUB_CTRL);
 280
 281        if (vhub->clk)
 282                clk_disable_unprepare(vhub->clk);
 283
 284        spin_unlock_irqrestore(&vhub->lock, flags);
 285
 286        if (vhub->ep0_bufs)
 287                dma_free_coherent(&pdev->dev,
 288                                  AST_VHUB_EP0_MAX_PACKET *
 289                                  (vhub->max_ports + 1),
 290                                  vhub->ep0_bufs,
 291                                  vhub->ep0_bufs_dma);
 292        vhub->ep0_bufs = NULL;
 293
 294        return 0;
 295}
 296
 297static int ast_vhub_probe(struct platform_device *pdev)
 298{
 299        enum usb_device_speed max_speed;
 300        struct ast_vhub *vhub;
 301        struct resource *res;
 302        int i, rc = 0;
 303        const struct device_node *np = pdev->dev.of_node;
 304
 305        vhub = devm_kzalloc(&pdev->dev, sizeof(*vhub), GFP_KERNEL);
 306        if (!vhub)
 307                return -ENOMEM;
 308
 309        rc = of_property_read_u32(np, "aspeed,vhub-downstream-ports",
 310                                  &vhub->max_ports);
 311        if (rc < 0)
 312                vhub->max_ports = AST_VHUB_NUM_PORTS;
 313
 314        vhub->ports = devm_kcalloc(&pdev->dev, vhub->max_ports,
 315                                   sizeof(*vhub->ports), GFP_KERNEL);
 316        if (!vhub->ports)
 317                return -ENOMEM;
 318
 319        rc = of_property_read_u32(np, "aspeed,vhub-generic-endpoints",
 320                                  &vhub->max_epns);
 321        if (rc < 0)
 322                vhub->max_epns = AST_VHUB_NUM_GEN_EPs;
 323
 324        vhub->epns = devm_kcalloc(&pdev->dev, vhub->max_epns,
 325                                  sizeof(*vhub->epns), GFP_KERNEL);
 326        if (!vhub->epns)
 327                return -ENOMEM;
 328
 329        spin_lock_init(&vhub->lock);
 330        vhub->pdev = pdev;
 331        vhub->port_irq_mask = GENMASK(VHUB_IRQ_DEV1_BIT + vhub->max_ports - 1,
 332                                      VHUB_IRQ_DEV1_BIT);
 333
 334        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 335        vhub->regs = devm_ioremap_resource(&pdev->dev, res);
 336        if (IS_ERR(vhub->regs)) {
 337                dev_err(&pdev->dev, "Failed to map resources\n");
 338                return PTR_ERR(vhub->regs);
 339        }
 340        UDCDBG(vhub, "vHub@%pR mapped @%p\n", res, vhub->regs);
 341
 342        platform_set_drvdata(pdev, vhub);
 343
 344        vhub->clk = devm_clk_get(&pdev->dev, NULL);
 345        if (IS_ERR(vhub->clk)) {
 346                rc = PTR_ERR(vhub->clk);
 347                goto err;
 348        }
 349        rc = clk_prepare_enable(vhub->clk);
 350        if (rc) {
 351                dev_err(&pdev->dev, "Error couldn't enable clock (%d)\n", rc);
 352                goto err;
 353        }
 354
 355        /* Check if we need to limit the HW to USB1 */
 356        max_speed = usb_get_maximum_speed(&pdev->dev);
 357        if (max_speed != USB_SPEED_UNKNOWN && max_speed < USB_SPEED_HIGH)
 358                vhub->force_usb1 = true;
 359
 360        /* Mask & ack all interrupts before installing the handler */
 361        writel(0, vhub->regs + AST_VHUB_IER);
 362        writel(VHUB_IRQ_ACK_ALL, vhub->regs + AST_VHUB_ISR);
 363
 364        /* Find interrupt and install handler */
 365        vhub->irq = platform_get_irq(pdev, 0);
 366        if (vhub->irq < 0) {
 367                rc = vhub->irq;
 368                goto err;
 369        }
 370        rc = devm_request_irq(&pdev->dev, vhub->irq, ast_vhub_irq, 0,
 371                              KBUILD_MODNAME, vhub);
 372        if (rc) {
 373                dev_err(&pdev->dev, "Failed to request interrupt\n");
 374                goto err;
 375        }
 376
 377        /*
 378         * Allocate DMA buffers for all EP0s in one chunk,
 379         * one per port and one for the vHub itself
 380         */
 381        vhub->ep0_bufs = dma_alloc_coherent(&pdev->dev,
 382                                            AST_VHUB_EP0_MAX_PACKET *
 383                                            (vhub->max_ports + 1),
 384                                            &vhub->ep0_bufs_dma, GFP_KERNEL);
 385        if (!vhub->ep0_bufs) {
 386                dev_err(&pdev->dev, "Failed to allocate EP0 DMA buffers\n");
 387                rc = -ENOMEM;
 388                goto err;
 389        }
 390        UDCVDBG(vhub, "EP0 DMA buffers @%p (DMA 0x%08x)\n",
 391                vhub->ep0_bufs, (u32)vhub->ep0_bufs_dma);
 392
 393        /* Init vHub EP0 */
 394        ast_vhub_init_ep0(vhub, &vhub->ep0, NULL);
 395
 396        /* Init devices */
 397        for (i = 0; i < vhub->max_ports && rc == 0; i++)
 398                rc = ast_vhub_init_dev(vhub, i);
 399        if (rc)
 400                goto err;
 401
 402        /* Init hub emulation */
 403        rc = ast_vhub_init_hub(vhub);
 404        if (rc)
 405                goto err;
 406
 407        /* Initialize HW */
 408        ast_vhub_init_hw(vhub);
 409
 410        dev_info(&pdev->dev, "Initialized virtual hub in USB%d mode\n",
 411                 vhub->force_usb1 ? 1 : 2);
 412
 413        return 0;
 414 err:
 415        ast_vhub_remove(pdev);
 416        return rc;
 417}
 418
 419static const struct of_device_id ast_vhub_dt_ids[] = {
 420        {
 421                .compatible = "aspeed,ast2400-usb-vhub",
 422        },
 423        {
 424                .compatible = "aspeed,ast2500-usb-vhub",
 425        },
 426        {
 427                .compatible = "aspeed,ast2600-usb-vhub",
 428        },
 429        { }
 430};
 431MODULE_DEVICE_TABLE(of, ast_vhub_dt_ids);
 432
 433static struct platform_driver ast_vhub_driver = {
 434        .probe          = ast_vhub_probe,
 435        .remove         = ast_vhub_remove,
 436        .driver         = {
 437                .name   = KBUILD_MODNAME,
 438                .of_match_table = ast_vhub_dt_ids,
 439        },
 440};
 441module_platform_driver(ast_vhub_driver);
 442
 443MODULE_DESCRIPTION("Aspeed vHub udc driver");
 444MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 445MODULE_LICENSE("GPL");
 446