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                unsigned long bitmap = istat;
 139                int offset = VHUB_IRQ_DEV1_BIT;
 140                int size = VHUB_IRQ_DEV1_BIT + vhub->max_ports;
 141
 142                for_each_set_bit_from(offset, &bitmap, size) {
 143                        i = offset - VHUB_IRQ_DEV1_BIT;
 144                        ast_vhub_dev_irq(&vhub->ports[i].dev);
 145                }
 146        }
 147
 148        /* Handle top-level vHub EP0 interrupts */
 149        if (istat & (VHUB_IRQ_HUB_EP0_OUT_ACK_STALL |
 150                     VHUB_IRQ_HUB_EP0_IN_ACK_STALL |
 151                     VHUB_IRQ_HUB_EP0_SETUP)) {
 152                if (istat & VHUB_IRQ_HUB_EP0_IN_ACK_STALL)
 153                        ast_vhub_ep0_handle_ack(&vhub->ep0, true);
 154                if (istat & VHUB_IRQ_HUB_EP0_OUT_ACK_STALL)
 155                        ast_vhub_ep0_handle_ack(&vhub->ep0, false);
 156                if (istat & VHUB_IRQ_HUB_EP0_SETUP)
 157                        ast_vhub_ep0_handle_setup(&vhub->ep0);
 158        }
 159
 160        /* Various top level bus events */
 161        if (istat & (VHUB_IRQ_BUS_RESUME |
 162                     VHUB_IRQ_BUS_SUSPEND |
 163                     VHUB_IRQ_BUS_RESET)) {
 164                if (istat & VHUB_IRQ_BUS_RESUME)
 165                        ast_vhub_hub_resume(vhub);
 166                if (istat & VHUB_IRQ_BUS_SUSPEND)
 167                        ast_vhub_hub_suspend(vhub);
 168                if (istat & VHUB_IRQ_BUS_RESET)
 169                        ast_vhub_hub_reset(vhub);
 170        }
 171
 172 bail:
 173        spin_unlock(&vhub->lock);
 174        return iret;
 175}
 176
 177void ast_vhub_init_hw(struct ast_vhub *vhub)
 178{
 179        u32 ctrl, port_mask, epn_mask;
 180
 181        UDCDBG(vhub,"(Re)Starting HW ...\n");
 182
 183        /* Enable PHY */
 184        ctrl = VHUB_CTRL_PHY_CLK |
 185                VHUB_CTRL_PHY_RESET_DIS;
 186
 187       /*
 188        * We do *NOT* set the VHUB_CTRL_CLK_STOP_SUSPEND bit
 189        * to stop the logic clock during suspend because
 190        * it causes the registers to become inaccessible and
 191        * we haven't yet figured out a good wayt to bring the
 192        * controller back into life to issue a wakeup.
 193        */
 194
 195        /*
 196         * Set some ISO & split control bits according to Aspeed
 197         * recommendation
 198         *
 199         * VHUB_CTRL_ISO_RSP_CTRL: When set tells the HW to respond
 200         * with 0 bytes data packet to ISO IN endpoints when no data
 201         * is available.
 202         *
 203         * VHUB_CTRL_SPLIT_IN: This makes a SOF complete a split IN
 204         * transaction.
 205         */
 206        ctrl |= VHUB_CTRL_ISO_RSP_CTRL | VHUB_CTRL_SPLIT_IN;
 207        writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 208        udelay(1);
 209
 210        /* Set descriptor ring size */
 211        if (AST_VHUB_DESCS_COUNT == 256) {
 212                ctrl |= VHUB_CTRL_LONG_DESC;
 213                writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 214        } else {
 215                BUILD_BUG_ON(AST_VHUB_DESCS_COUNT != 32);
 216        }
 217
 218        /* Reset all devices */
 219        port_mask = GENMASK(vhub->max_ports, 1);
 220        writel(VHUB_SW_RESET_ROOT_HUB |
 221               VHUB_SW_RESET_DMA_CONTROLLER |
 222               VHUB_SW_RESET_EP_POOL |
 223               port_mask, 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        epn_mask = GENMASK(vhub->max_epns - 1, 0);
 229        writel(0, vhub->regs + AST_VHUB_EP_ACK_IER);
 230        writel(0, vhub->regs + AST_VHUB_EP_NACK_IER);
 231        writel(epn_mask, vhub->regs + AST_VHUB_EP_ACK_ISR);
 232        writel(epn_mask, vhub->regs + AST_VHUB_EP_NACK_ISR);
 233
 234        /* Default settings for EP0, enable HW hub EP1 */
 235        writel(0, vhub->regs + AST_VHUB_EP0_CTRL);
 236        writel(VHUB_EP1_CTRL_RESET_TOGGLE |
 237               VHUB_EP1_CTRL_ENABLE,
 238               vhub->regs + AST_VHUB_EP1_CTRL);
 239        writel(0, vhub->regs + AST_VHUB_EP1_STS_CHG);
 240
 241        /* Configure EP0 DMA buffer */
 242        writel(vhub->ep0.buf_dma, vhub->regs + AST_VHUB_EP0_DATA);
 243
 244        /* Clear address */
 245        writel(0, vhub->regs + AST_VHUB_CONF);
 246
 247        /* Pullup hub (activate on host) */
 248        if (vhub->force_usb1)
 249                ctrl |= VHUB_CTRL_FULL_SPEED_ONLY;
 250
 251        ctrl |= VHUB_CTRL_UPSTREAM_CONNECT;
 252        writel(ctrl, vhub->regs + AST_VHUB_CTRL);
 253
 254        /* Enable some interrupts */
 255        writel(VHUB_IRQ_HUB_EP0_IN_ACK_STALL |
 256               VHUB_IRQ_HUB_EP0_OUT_ACK_STALL |
 257               VHUB_IRQ_HUB_EP0_SETUP |
 258               VHUB_IRQ_EP_POOL_ACK_STALL |
 259               VHUB_IRQ_BUS_RESUME |
 260               VHUB_IRQ_BUS_SUSPEND |
 261               VHUB_IRQ_BUS_RESET,
 262               vhub->regs + AST_VHUB_IER);
 263}
 264
 265static int ast_vhub_remove(struct platform_device *pdev)
 266{
 267        struct ast_vhub *vhub = platform_get_drvdata(pdev);
 268        unsigned long flags;
 269        int i;
 270
 271        if (!vhub || !vhub->regs)
 272                return 0;
 273
 274        /* Remove devices */
 275        for (i = 0; i < vhub->max_ports; i++)
 276                ast_vhub_del_dev(&vhub->ports[i].dev);
 277
 278        spin_lock_irqsave(&vhub->lock, flags);
 279
 280        /* Mask & ack all interrupts  */
 281        writel(0, vhub->regs + AST_VHUB_IER);
 282        writel(VHUB_IRQ_ACK_ALL, vhub->regs + AST_VHUB_ISR);
 283
 284        /* Pull device, leave PHY enabled */
 285        writel(VHUB_CTRL_PHY_CLK |
 286               VHUB_CTRL_PHY_RESET_DIS,
 287               vhub->regs + AST_VHUB_CTRL);
 288
 289        if (vhub->clk)
 290                clk_disable_unprepare(vhub->clk);
 291
 292        spin_unlock_irqrestore(&vhub->lock, flags);
 293
 294        if (vhub->ep0_bufs)
 295                dma_free_coherent(&pdev->dev,
 296                                  AST_VHUB_EP0_MAX_PACKET *
 297                                  (vhub->max_ports + 1),
 298                                  vhub->ep0_bufs,
 299                                  vhub->ep0_bufs_dma);
 300        vhub->ep0_bufs = NULL;
 301
 302        return 0;
 303}
 304
 305static int ast_vhub_probe(struct platform_device *pdev)
 306{
 307        enum usb_device_speed max_speed;
 308        struct ast_vhub *vhub;
 309        struct resource *res;
 310        int i, rc = 0;
 311        const struct device_node *np = pdev->dev.of_node;
 312
 313        vhub = devm_kzalloc(&pdev->dev, sizeof(*vhub), GFP_KERNEL);
 314        if (!vhub)
 315                return -ENOMEM;
 316
 317        rc = of_property_read_u32(np, "aspeed,vhub-downstream-ports",
 318                                  &vhub->max_ports);
 319        if (rc < 0)
 320                vhub->max_ports = AST_VHUB_NUM_PORTS;
 321
 322        vhub->ports = devm_kcalloc(&pdev->dev, vhub->max_ports,
 323                                   sizeof(*vhub->ports), GFP_KERNEL);
 324        if (!vhub->ports)
 325                return -ENOMEM;
 326
 327        rc = of_property_read_u32(np, "aspeed,vhub-generic-endpoints",
 328                                  &vhub->max_epns);
 329        if (rc < 0)
 330                vhub->max_epns = AST_VHUB_NUM_GEN_EPs;
 331
 332        vhub->epns = devm_kcalloc(&pdev->dev, vhub->max_epns,
 333                                  sizeof(*vhub->epns), GFP_KERNEL);
 334        if (!vhub->epns)
 335                return -ENOMEM;
 336
 337        spin_lock_init(&vhub->lock);
 338        vhub->pdev = pdev;
 339        vhub->port_irq_mask = GENMASK(VHUB_IRQ_DEV1_BIT + vhub->max_ports - 1,
 340                                      VHUB_IRQ_DEV1_BIT);
 341
 342        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 343        vhub->regs = devm_ioremap_resource(&pdev->dev, res);
 344        if (IS_ERR(vhub->regs)) {
 345                dev_err(&pdev->dev, "Failed to map resources\n");
 346                return PTR_ERR(vhub->regs);
 347        }
 348        UDCDBG(vhub, "vHub@%pR mapped @%p\n", res, vhub->regs);
 349
 350        platform_set_drvdata(pdev, vhub);
 351
 352        vhub->clk = devm_clk_get(&pdev->dev, NULL);
 353        if (IS_ERR(vhub->clk)) {
 354                rc = PTR_ERR(vhub->clk);
 355                goto err;
 356        }
 357        rc = clk_prepare_enable(vhub->clk);
 358        if (rc) {
 359                dev_err(&pdev->dev, "Error couldn't enable clock (%d)\n", rc);
 360                goto err;
 361        }
 362
 363        /* Check if we need to limit the HW to USB1 */
 364        max_speed = usb_get_maximum_speed(&pdev->dev);
 365        if (max_speed != USB_SPEED_UNKNOWN && max_speed < USB_SPEED_HIGH)
 366                vhub->force_usb1 = true;
 367
 368        /* Mask & ack all interrupts before installing the handler */
 369        writel(0, vhub->regs + AST_VHUB_IER);
 370        writel(VHUB_IRQ_ACK_ALL, vhub->regs + AST_VHUB_ISR);
 371
 372        /* Find interrupt and install handler */
 373        vhub->irq = platform_get_irq(pdev, 0);
 374        if (vhub->irq < 0) {
 375                rc = vhub->irq;
 376                goto err;
 377        }
 378        rc = devm_request_irq(&pdev->dev, vhub->irq, ast_vhub_irq, 0,
 379                              KBUILD_MODNAME, vhub);
 380        if (rc) {
 381                dev_err(&pdev->dev, "Failed to request interrupt\n");
 382                goto err;
 383        }
 384
 385        /*
 386         * Allocate DMA buffers for all EP0s in one chunk,
 387         * one per port and one for the vHub itself
 388         */
 389        vhub->ep0_bufs = dma_alloc_coherent(&pdev->dev,
 390                                            AST_VHUB_EP0_MAX_PACKET *
 391                                            (vhub->max_ports + 1),
 392                                            &vhub->ep0_bufs_dma, GFP_KERNEL);
 393        if (!vhub->ep0_bufs) {
 394                dev_err(&pdev->dev, "Failed to allocate EP0 DMA buffers\n");
 395                rc = -ENOMEM;
 396                goto err;
 397        }
 398        UDCVDBG(vhub, "EP0 DMA buffers @%p (DMA 0x%08x)\n",
 399                vhub->ep0_bufs, (u32)vhub->ep0_bufs_dma);
 400
 401        /* Init vHub EP0 */
 402        ast_vhub_init_ep0(vhub, &vhub->ep0, NULL);
 403
 404        /* Init devices */
 405        for (i = 0; i < vhub->max_ports && rc == 0; i++)
 406                rc = ast_vhub_init_dev(vhub, i);
 407        if (rc)
 408                goto err;
 409
 410        /* Init hub emulation */
 411        rc = ast_vhub_init_hub(vhub);
 412        if (rc)
 413                goto err;
 414
 415        /* Initialize HW */
 416        ast_vhub_init_hw(vhub);
 417
 418        dev_info(&pdev->dev, "Initialized virtual hub in USB%d mode\n",
 419                 vhub->force_usb1 ? 1 : 2);
 420
 421        return 0;
 422 err:
 423        ast_vhub_remove(pdev);
 424        return rc;
 425}
 426
 427static const struct of_device_id ast_vhub_dt_ids[] = {
 428        {
 429                .compatible = "aspeed,ast2400-usb-vhub",
 430        },
 431        {
 432                .compatible = "aspeed,ast2500-usb-vhub",
 433        },
 434        {
 435                .compatible = "aspeed,ast2600-usb-vhub",
 436        },
 437        { }
 438};
 439MODULE_DEVICE_TABLE(of, ast_vhub_dt_ids);
 440
 441static struct platform_driver ast_vhub_driver = {
 442        .probe          = ast_vhub_probe,
 443        .remove         = ast_vhub_remove,
 444        .driver         = {
 445                .name   = KBUILD_MODNAME,
 446                .of_match_table = ast_vhub_dt_ids,
 447        },
 448};
 449module_platform_driver(ast_vhub_driver);
 450
 451MODULE_DESCRIPTION("Aspeed vHub udc driver");
 452MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 453MODULE_LICENSE("GPL");
 454