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