drivers/rpmsg/qcom_glink_rpm.c

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