drivers/rpmsg/qcom_glink_rpm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2016-2017, Linaro Ltd
   4  */
   5
   6 #include <linux/idr.h>
   7 #include <linux/interrupt.h>
   8 #include <linux/io.h>
   9 #include <linux/list.h>
  10 #include <linux/mfd/syscon.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/of_address.h>
  14 #include <linux/of_irq.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/regmap.h>
  17 #include <linux/rpmsg.h>
  18 #include <linux/slab.h>
  19 #include <linux/workqueue.h>
  20 #include <linux/mailbox_client.h>
  21
  22 #include "rpmsg_internal.h"
  23 #include "qcom_glink_native.h"
  24
  25 #define RPM_TOC_SIZE            256
  26 #define RPM_TOC_MAGIC           0x67727430 /* grt0 */
  27 #define RPM_TOC_MAX_ENTRIES     ((RPM_TOC_SIZE - sizeof(struct rpm_toc)) / \
  28                                  sizeof(struct rpm_toc_entry))
  29
  30 #define RPM_TX_FIFO_ID          0x61703272 /* ap2r */
  31 #define RPM_RX_FIFO_ID          0x72326170 /* r2ap */
  32
  33 #define to_rpm_pipe(p) container_of(p, struct glink_rpm_pipe, native)
  34
  35 struct rpm_toc_entry {
  36         __le32 id;
  37         __le32 offset;
  38         __le32 size;
  39 } __packed;
  40
  41 struct rpm_toc {
  42         __le32 magic;
  43         __le32 count;
  44
  45         struct rpm_toc_entry entries[];
  46 } __packed;
  47
  48 struct glink_rpm_pipe {
  49         struct qcom_glink_pipe native;
  50
  51         void __iomem *tail;
  52         void __iomem *head;
  53
  54         void __iomem *fifo;
  55 };
  56
  57 struct glink_rpm {
  58         struct qcom_glink *glink;
  59
  60         int irq;
  61
  62         struct mbox_client mbox_client;
  63         struct mbox_chan *mbox_chan;
  64
  65         struct glink_rpm_pipe rx_pipe;
  66         struct glink_rpm_pipe tx_pipe;
  67 };
  68
  69 static size_t glink_rpm_rx_avail(struct qcom_glink_pipe *glink_pipe)
  70 {
  71         struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
  72         unsigned int head;
  73         unsigned int tail;
  74
  75         head = readl(pipe->head);
  76         tail = readl(pipe->tail);
  77
  78         if (head < tail)
  79                 return pipe->native.length - tail + head;
  80         else
  81                 return head - tail;
  82 }
  83
  84 static void glink_rpm_rx_peek(struct qcom_glink_pipe *glink_pipe,
  85                               void *data, unsigned int offset, size_t count)
  86 {
  87         struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
  88         unsigned int tail;
  89         size_t len;
  90
  91         tail = readl(pipe->tail);
  92         tail += offset;
  93         if (tail >= pipe->native.length)
  94                 tail -= pipe->native.length;
  95
  96         len = min_t(size_t, count, pipe->native.length - tail);
  97         if (len) {
  98                 __ioread32_copy(data, pipe->fifo + tail,
  99                                 len / sizeof(u32));
 100         }
 101
 102         if (len != count) {
 103                 __ioread32_copy(data + len, pipe->fifo,
 104                                 (count - len) / sizeof(u32));
 105         }
 106 }
 107
 108 static void glink_rpm_rx_advance(struct qcom_glink_pipe *glink_pipe,
 109                                  size_t count)
 110 {
 111         struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 112         unsigned int tail;
 113
 114         tail = readl(pipe->tail);
 115
 116         tail += count;
 117         if (tail >= pipe->native.length)
 118                 tail -= pipe->native.length;
 119
 120         writel(tail, pipe->tail);
 121 }
 122
 123 static size_t glink_rpm_tx_avail(struct qcom_glink_pipe *glink_pipe)
 124 {
 125         struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 126         unsigned int head;
 127         unsigned int tail;
 128
 129         head = readl(pipe->head);
 130         tail = readl(pipe->tail);
 131
 132         if (tail <= head)
 133                 return pipe->native.length - head + tail;
 134         else
 135                 return tail - head;
 136 }
 137
 138 static unsigned int glink_rpm_tx_write_one(struct glink_rpm_pipe *pipe,
 139                                            unsigned int head,
 140                                            const void *data, size_t count)
 141 {
 142         size_t len;
 143
 144         len = min_t(size_t, count, pipe->native.length - head);
 145         if (len) {
 146                 __iowrite32_copy(pipe->fifo + head, data,
 147                                  len / sizeof(u32));
 148         }
 149
 150         if (len != count) {
 151                 __iowrite32_copy(pipe->fifo, data + len,
 152                                  (count - len) / sizeof(u32));
 153         }
 154
 155         head += count;
 156         if (head >= pipe->native.length)
 157                 head -= pipe->native.length;
 158
 159         return head;
 160 }
 161
 162 static void glink_rpm_tx_write(struct qcom_glink_pipe *glink_pipe,
 163                                const void *hdr, size_t hlen,
 164                                const void *data, size_t dlen)
 165 {
 166         struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 167         size_t tlen = hlen + dlen;
 168         size_t aligned_dlen;
 169         unsigned int head;
 170         char padding[8] = {0};
 171         size_t pad;
 172
 173         /* Header length comes from glink native and is always 4 byte aligned */
 174         if (WARN(hlen % 4, "Glink Header length must be 4 bytes aligned\n"))
 175                 return;
 176
 177         /*
 178          * Move the unaligned tail of the message to the padding chunk, to
 179          * ensure word aligned accesses
 180          */
 181         aligned_dlen = ALIGN_DOWN(dlen, 4);
 182         if (aligned_dlen != dlen)
 183                 memcpy(padding, data + aligned_dlen, dlen - aligned_dlen);
 184
 185         head = readl(pipe->head);
 186         head = glink_rpm_tx_write_one(pipe, head, hdr, hlen);
 187         head = glink_rpm_tx_write_one(pipe, head, data, aligned_dlen);
 188
 189         pad = ALIGN(tlen, 8) - ALIGN_DOWN(tlen, 4);
 190         if (pad)
 191                 head = glink_rpm_tx_write_one(pipe, head, padding, pad);
 192         writel(head, pipe->head);
 193 }
 194
 195 static void glink_rpm_tx_kick(struct qcom_glink_pipe *glink_pipe)
 196 {
 197         struct glink_rpm_pipe *pipe = to_rpm_pipe(glink_pipe);
 198         struct glink_rpm *rpm = container_of(pipe, struct glink_rpm, tx_pipe);
 199
 200         mbox_send_message(rpm->mbox_chan, NULL);
 201         mbox_client_txdone(rpm->mbox_chan, 0);
 202 }
 203
 204 static irqreturn_t qcom_glink_rpm_intr(int irq, void *data)
 205 {
 206         struct glink_rpm *rpm = data;
 207
 208         qcom_glink_native_rx(rpm->glink);
 209
 210         return IRQ_HANDLED;
 211 }
 212
 213 static int glink_rpm_parse_toc(struct device *dev,
 214                                void __iomem *msg_ram,
 215                                size_t msg_ram_size,
 216                                struct glink_rpm_pipe *rx,
 217                                struct glink_rpm_pipe *tx)
 218 {
 219         struct rpm_toc *toc;
 220         int num_entries;
 221         unsigned int id;
 222         size_t offset;
 223         size_t size;
 224         void *buf;
 225         int i;
 226
 227         buf = kzalloc(RPM_TOC_SIZE, GFP_KERNEL);
 228         if (!buf)
 229                 return -ENOMEM;
 230
 231         __ioread32_copy(buf, msg_ram + msg_ram_size - RPM_TOC_SIZE,
 232                         RPM_TOC_SIZE / sizeof(u32));
 233
 234         toc = buf;
 235
 236         if (le32_to_cpu(toc->magic) != RPM_TOC_MAGIC) {
 237                 dev_err(dev, "RPM TOC has invalid magic\n");
 238                 goto err_inval;
 239         }
 240
 241         num_entries = le32_to_cpu(toc->count);
 242         if (num_entries > RPM_TOC_MAX_ENTRIES) {
 243                 dev_err(dev, "Invalid number of toc entries\n");
 244                 goto err_inval;
 245         }
 246
 247         for (i = 0; i < num_entries; i++) {
 248                 id = le32_to_cpu(toc->entries[i].id);
 249                 offset = le32_to_cpu(toc->entries[i].offset);
 250                 size = le32_to_cpu(toc->entries[i].size);
 251
 252                 if (offset > msg_ram_size || offset + size > msg_ram_size) {
 253                         dev_err(dev, "TOC entry with invalid size\n");
 254                         continue;
 255                 }
 256
 257                 switch (id) {
 258                 case RPM_RX_FIFO_ID:
 259                         rx->native.length = size;
 260
 261                         rx->tail = msg_ram + offset;
 262                         rx->head = msg_ram + offset + sizeof(u32);
 263                         rx->fifo = msg_ram + offset + 2 * sizeof(u32);
 264                         break;
 265                 case RPM_TX_FIFO_ID:
 266                         tx->native.length = size;
 267
 268                         tx->tail = msg_ram + offset;
 269                         tx->head = msg_ram + offset + sizeof(u32);
 270                         tx->fifo = msg_ram + offset + 2 * sizeof(u32);
 271                         break;
 272                 }
 273         }
 274
 275         if (!rx->fifo || !tx->fifo) {
 276                 dev_err(dev, "Unable to find rx and tx descriptors\n");
 277                 goto err_inval;
 278         }
 279
 280         kfree(buf);
 281         return 0;
 282
 283 err_inval:
 284         kfree(buf);
 285         return -EINVAL;
 286 }
 287
 288 static int glink_rpm_probe(struct platform_device *pdev)
 289 {
 290         struct qcom_glink *glink;
 291         struct glink_rpm *rpm;
 292         struct device_node *np;
 293         void __iomem *msg_ram;
 294         size_t msg_ram_size;
 295         struct device *dev = &pdev->dev;
 296         struct resource r;
 297         int ret;
 298
 299         rpm = devm_kzalloc(&pdev->dev, sizeof(*rpm), GFP_KERNEL);
 300         if (!rpm)
 301                 return -ENOMEM;
 302
 303         np = of_parse_phandle(dev->of_node, "qcom,rpm-msg-ram", 0);
 304         ret = of_address_to_resource(np, 0, &r);
 305         of_node_put(np);
 306         if (ret)
 307                 return ret;
 308
 309         msg_ram = devm_ioremap(dev, r.start, resource_size(&r));
 310         msg_ram_size = resource_size(&r);
 311         if (!msg_ram)
 312                 return -ENOMEM;
 313
 314         ret = glink_rpm_parse_toc(dev, msg_ram, msg_ram_size,
 315                                   &rpm->rx_pipe, &rpm->tx_pipe);
 316         if (ret)
 317                 return ret;
 318
 319         rpm->irq = of_irq_get(dev->of_node, 0);
 320         ret = devm_request_irq(dev, rpm->irq, qcom_glink_rpm_intr,
 321                                IRQF_NO_SUSPEND | IRQF_NO_AUTOEN,
 322                                "glink-rpm", rpm);
 323         if (ret) {
 324                 dev_err(dev, "failed to request IRQ\n");
 325                 return ret;
 326         }
 327
 328         rpm->mbox_client.dev = dev;
 329         rpm->mbox_client.knows_txdone = true;
 330         rpm->mbox_chan = mbox_request_channel(&rpm->mbox_client, 0);
 331         if (IS_ERR(rpm->mbox_chan))
 332                 return dev_err_probe(dev, PTR_ERR(rpm->mbox_chan), "failed to acquire IPC channel\n");
 333
 334         /* Pipe specific accessors */
 335         rpm->rx_pipe.native.avail = glink_rpm_rx_avail;
 336         rpm->rx_pipe.native.peek = glink_rpm_rx_peek;
 337         rpm->rx_pipe.native.advance = glink_rpm_rx_advance;
 338         rpm->tx_pipe.native.avail = glink_rpm_tx_avail;
 339         rpm->tx_pipe.native.write = glink_rpm_tx_write;
 340         rpm->tx_pipe.native.kick = glink_rpm_tx_kick;
 341
 342         writel(0, rpm->tx_pipe.head);
 343         writel(0, rpm->rx_pipe.tail);
 344
 345         glink = qcom_glink_native_probe(dev,
 346                                         0,
 347                                         &rpm->rx_pipe.native,
 348                                         &rpm->tx_pipe.native,
 349                                         true);
 350         if (IS_ERR(glink)) {
 351                 mbox_free_channel(rpm->mbox_chan);
 352                 return PTR_ERR(glink);
 353         }
 354
 355         rpm->glink = glink;
 356
 357         platform_set_drvdata(pdev, rpm);
 358
 359         enable_irq(rpm->irq);
 360
 361         return 0;
 362 }
 363
 364 static void glink_rpm_remove(struct platform_device *pdev)
 365 {
 366         struct glink_rpm *rpm = platform_get_drvdata(pdev);
 367         struct qcom_glink *glink = rpm->glink;
 368
 369         disable_irq(rpm->irq);
 370
 371         qcom_glink_native_remove(glink);
 372
 373         mbox_free_channel(rpm->mbox_chan);
 374 }
 375
 376 static const struct of_device_id glink_rpm_of_match[] = {
 377         { .compatible = "qcom,glink-rpm" },
 378         {}
 379 };
 380 MODULE_DEVICE_TABLE(of, glink_rpm_of_match);
 381
 382 static struct platform_driver glink_rpm_driver = {
 383         .probe = glink_rpm_probe,
 384         .remove_new = glink_rpm_remove,
 385         .driver = {
 386                 .name = "qcom_glink_rpm",
 387                 .of_match_table = glink_rpm_of_match,
 388         },
 389 };
 390
 391 static int __init glink_rpm_init(void)
 392 {
 393         return platform_driver_register(&glink_rpm_driver);
 394 }
 395 subsys_initcall(glink_rpm_init);
 396
 397 static void __exit glink_rpm_exit(void)
 398 {
 399         platform_driver_unregister(&glink_rpm_driver);
 400 }
 401 module_exit(glink_rpm_exit);
 402
 403 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@linaro.org>");
 404 MODULE_DESCRIPTION("Qualcomm GLINK RPM driver");
 405 MODULE_LICENSE("GPL v2");