drivers/mailbox/hi6220-mailbox.c

   1 /*
   2  * Hisilicon's Hi6220 mailbox driver
   3  *
   4  * Copyright (c) 2015 Hisilicon Limited.
   5  * Copyright (c) 2015 Linaro Limited.
   6  *
   7  * Author: Leo Yan <leo.yan@linaro.org>
   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, version 2 of the License.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  */
  19
  20 #include <linux/device.h>
  21 #include <linux/err.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/io.h>
  24 #include <linux/kfifo.h>
  25 #include <linux/mailbox_controller.h>
  26 #include <linux/module.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/slab.h>
  29
  30 #define MBOX_CHAN_MAX                   32
  31
  32 #define MBOX_TX                         0x1
  33
  34 /* Mailbox message length: 8 words */
  35 #define MBOX_MSG_LEN                    8
  36
  37 /* Mailbox Registers */
  38 #define MBOX_OFF(m)                     (0x40 * (m))
  39 #define MBOX_MODE_REG(m)                (MBOX_OFF(m) + 0x0)
  40 #define MBOX_DATA_REG(m)                (MBOX_OFF(m) + 0x4)
  41
  42 #define MBOX_STATE_MASK                 (0xF << 4)
  43 #define MBOX_STATE_IDLE                 (0x1 << 4)
  44 #define MBOX_STATE_TX                   (0x2 << 4)
  45 #define MBOX_STATE_RX                   (0x4 << 4)
  46 #define MBOX_STATE_ACK                  (0x8 << 4)
  47 #define MBOX_ACK_CONFIG_MASK            (0x1 << 0)
  48 #define MBOX_ACK_AUTOMATIC              (0x1 << 0)
  49 #define MBOX_ACK_IRQ                    (0x0 << 0)
  50
  51 /* IPC registers */
  52 #define ACK_INT_RAW_REG(i)              ((i) + 0x400)
  53 #define ACK_INT_MSK_REG(i)              ((i) + 0x404)
  54 #define ACK_INT_STAT_REG(i)             ((i) + 0x408)
  55 #define ACK_INT_CLR_REG(i)              ((i) + 0x40c)
  56 #define ACK_INT_ENA_REG(i)              ((i) + 0x500)
  57 #define ACK_INT_DIS_REG(i)              ((i) + 0x504)
  58 #define DST_INT_RAW_REG(i)              ((i) + 0x420)
  59
  60
  61 struct hi6220_mbox_chan {
  62
  63         /*
  64          * Description for channel's hardware info:
  65          *  - direction: tx or rx
  66          *  - dst irq: peer core's irq number
  67          *  - ack irq: local irq number
  68          *  - slot number
  69          */
  70         unsigned int dir, dst_irq, ack_irq;
  71         unsigned int slot;
  72
  73         struct hi6220_mbox *parent;
  74 };
  75
  76 struct hi6220_mbox {
  77         struct device *dev;
  78
  79         int irq;
  80
  81         /* flag of enabling tx's irq mode */
  82         bool tx_irq_mode;
  83
  84         /* region for ipc event */
  85         void __iomem *ipc;
  86
  87         /* region for mailbox */
  88         void __iomem *base;
  89
  90         unsigned int chan_num;
  91         struct hi6220_mbox_chan *mchan;
  92
  93         void *irq_map_chan[MBOX_CHAN_MAX];
  94         struct mbox_chan *chan;
  95         struct mbox_controller controller;
  96 };
  97
  98 static void mbox_set_state(struct hi6220_mbox *mbox,
  99                            unsigned int slot, u32 val)
 100 {
 101         u32 status;
 102
 103         status = readl(mbox->base + MBOX_MODE_REG(slot));
 104         status = (status & ~MBOX_STATE_MASK) | val;
 105         writel(status, mbox->base + MBOX_MODE_REG(slot));
 106 }
 107
 108 static void mbox_set_mode(struct hi6220_mbox *mbox,
 109                           unsigned int slot, u32 val)
 110 {
 111         u32 mode;
 112
 113         mode = readl(mbox->base + MBOX_MODE_REG(slot));
 114         mode = (mode & ~MBOX_ACK_CONFIG_MASK) | val;
 115         writel(mode, mbox->base + MBOX_MODE_REG(slot));
 116 }
 117
 118 static bool hi6220_mbox_last_tx_done(struct mbox_chan *chan)
 119 {
 120         struct hi6220_mbox_chan *mchan = chan->con_priv;
 121         struct hi6220_mbox *mbox = mchan->parent;
 122         u32 state;
 123
 124         /* Only set idle state for polling mode */
 125         BUG_ON(mbox->tx_irq_mode);
 126
 127         state = readl(mbox->base + MBOX_MODE_REG(mchan->slot));
 128         return ((state & MBOX_STATE_MASK) == MBOX_STATE_IDLE);
 129 }
 130
 131 static int hi6220_mbox_send_data(struct mbox_chan *chan, void *msg)
 132 {
 133         struct hi6220_mbox_chan *mchan = chan->con_priv;
 134         struct hi6220_mbox *mbox = mchan->parent;
 135         unsigned int slot = mchan->slot;
 136         u32 *buf = msg;
 137         int i;
 138
 139         /* indicate as a TX channel */
 140         mchan->dir = MBOX_TX;
 141
 142         mbox_set_state(mbox, slot, MBOX_STATE_TX);
 143
 144         if (mbox->tx_irq_mode)
 145                 mbox_set_mode(mbox, slot, MBOX_ACK_IRQ);
 146         else
 147                 mbox_set_mode(mbox, slot, MBOX_ACK_AUTOMATIC);
 148
 149         for (i = 0; i < MBOX_MSG_LEN; i++)
 150                 writel(buf[i], mbox->base + MBOX_DATA_REG(slot) + i * 4);
 151
 152         /* trigger remote request */
 153         writel(BIT(mchan->dst_irq), DST_INT_RAW_REG(mbox->ipc));
 154         return 0;
 155 }
 156
 157 static irqreturn_t hi6220_mbox_interrupt(int irq, void *p)
 158 {
 159         struct hi6220_mbox *mbox = p;
 160         struct hi6220_mbox_chan *mchan;
 161         struct mbox_chan *chan;
 162         unsigned int state, intr_bit, i;
 163         u32 msg[MBOX_MSG_LEN];
 164
 165         state = readl(ACK_INT_STAT_REG(mbox->ipc));
 166         if (!state) {
 167                 dev_warn(mbox->dev, "%s: spurious interrupt\n",
 168                          __func__);
 169                 return IRQ_HANDLED;
 170         }
 171
 172         while (state) {
 173                 intr_bit = __ffs(state);
 174                 state &= (state - 1);
 175
 176                 chan = mbox->irq_map_chan[intr_bit];
 177                 if (!chan) {
 178                         dev_warn(mbox->dev, "%s: unexpected irq vector %d\n",
 179                                  __func__, intr_bit);
 180                         continue;
 181                 }
 182
 183                 mchan = chan->con_priv;
 184                 if (mchan->dir == MBOX_TX)
 185                         mbox_chan_txdone(chan, 0);
 186                 else {
 187                         for (i = 0; i < MBOX_MSG_LEN; i++)
 188                                 msg[i] = readl(mbox->base +
 189                                         MBOX_DATA_REG(mchan->slot) + i * 4);
 190
 191                         mbox_chan_received_data(chan, (void *)msg);
 192                 }
 193
 194                 /* clear IRQ source */
 195                 writel(BIT(mchan->ack_irq), ACK_INT_CLR_REG(mbox->ipc));
 196                 mbox_set_state(mbox, mchan->slot, MBOX_STATE_IDLE);
 197         }
 198
 199         return IRQ_HANDLED;
 200 }
 201
 202 static int hi6220_mbox_startup(struct mbox_chan *chan)
 203 {
 204         struct hi6220_mbox_chan *mchan = chan->con_priv;
 205         struct hi6220_mbox *mbox = mchan->parent;
 206
 207         mchan->dir = 0;
 208
 209         /* enable interrupt */
 210         writel(BIT(mchan->ack_irq), ACK_INT_ENA_REG(mbox->ipc));
 211         return 0;
 212 }
 213
 214 static void hi6220_mbox_shutdown(struct mbox_chan *chan)
 215 {
 216         struct hi6220_mbox_chan *mchan = chan->con_priv;
 217         struct hi6220_mbox *mbox = mchan->parent;
 218
 219         /* disable interrupt */
 220         writel(BIT(mchan->ack_irq), ACK_INT_DIS_REG(mbox->ipc));
 221         mbox->irq_map_chan[mchan->ack_irq] = NULL;
 222 }
 223
 224 static const struct mbox_chan_ops hi6220_mbox_ops = {
 225         .send_data    = hi6220_mbox_send_data,
 226         .startup      = hi6220_mbox_startup,
 227         .shutdown     = hi6220_mbox_shutdown,
 228         .last_tx_done = hi6220_mbox_last_tx_done,
 229 };
 230
 231 static struct mbox_chan *hi6220_mbox_xlate(struct mbox_controller *controller,
 232                                            const struct of_phandle_args *spec)
 233 {
 234         struct hi6220_mbox *mbox = dev_get_drvdata(controller->dev);
 235         struct hi6220_mbox_chan *mchan;
 236         struct mbox_chan *chan;
 237         unsigned int i = spec->args[0];
 238         unsigned int dst_irq = spec->args[1];
 239         unsigned int ack_irq = spec->args[2];
 240
 241         /* Bounds checking */
 242         if (i >= mbox->chan_num || dst_irq >= mbox->chan_num ||
 243             ack_irq >= mbox->chan_num) {
 244                 dev_err(mbox->dev,
 245                         "Invalid channel idx %d dst_irq %d ack_irq %d\n",
 246                         i, dst_irq, ack_irq);
 247                 return ERR_PTR(-EINVAL);
 248         }
 249
 250         /* Is requested channel free? */
 251         chan = &mbox->chan[i];
 252         if (mbox->irq_map_chan[ack_irq] == (void *)chan) {
 253                 dev_err(mbox->dev, "Channel in use\n");
 254                 return ERR_PTR(-EBUSY);
 255         }
 256
 257         mchan = chan->con_priv;
 258         mchan->dst_irq = dst_irq;
 259         mchan->ack_irq = ack_irq;
 260
 261         mbox->irq_map_chan[ack_irq] = (void *)chan;
 262         return chan;
 263 }
 264
 265 static const struct of_device_id hi6220_mbox_of_match[] = {
 266         { .compatible = "hisilicon,hi6220-mbox", },
 267         {},
 268 };
 269 MODULE_DEVICE_TABLE(of, hi6220_mbox_of_match);
 270
 271 static int hi6220_mbox_probe(struct platform_device *pdev)
 272 {
 273         struct device_node *node = pdev->dev.of_node;
 274         struct device *dev = &pdev->dev;
 275         struct hi6220_mbox *mbox;
 276         struct resource *res;
 277         int i, err;
 278
 279         mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
 280         if (!mbox)
 281                 return -ENOMEM;
 282
 283         mbox->dev = dev;
 284         mbox->chan_num = MBOX_CHAN_MAX;
 285         mbox->mchan = devm_kcalloc(dev,
 286                 mbox->chan_num, sizeof(*mbox->mchan), GFP_KERNEL);
 287         if (!mbox->mchan)
 288                 return -ENOMEM;
 289
 290         mbox->chan = devm_kcalloc(dev,
 291                 mbox->chan_num, sizeof(*mbox->chan), GFP_KERNEL);
 292         if (!mbox->chan)
 293                 return -ENOMEM;
 294
 295         mbox->irq = platform_get_irq(pdev, 0);
 296         if (mbox->irq < 0)
 297                 return mbox->irq;
 298
 299         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 300         mbox->ipc = devm_ioremap_resource(dev, res);
 301         if (IS_ERR(mbox->ipc)) {
 302                 dev_err(dev, "ioremap ipc failed\n");
 303                 return PTR_ERR(mbox->ipc);
 304         }
 305
 306         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 307         mbox->base = devm_ioremap_resource(dev, res);
 308         if (IS_ERR(mbox->base)) {
 309                 dev_err(dev, "ioremap buffer failed\n");
 310                 return PTR_ERR(mbox->base);
 311         }
 312
 313         err = devm_request_irq(dev, mbox->irq, hi6220_mbox_interrupt, 0,
 314                         dev_name(dev), mbox);
 315         if (err) {
 316                 dev_err(dev, "Failed to register a mailbox IRQ handler: %d\n",
 317                         err);
 318                 return -ENODEV;
 319         }
 320
 321         mbox->controller.dev = dev;
 322         mbox->controller.chans = &mbox->chan[0];
 323         mbox->controller.num_chans = mbox->chan_num;
 324         mbox->controller.ops = &hi6220_mbox_ops;
 325         mbox->controller.of_xlate = hi6220_mbox_xlate;
 326
 327         for (i = 0; i < mbox->chan_num; i++) {
 328                 mbox->chan[i].con_priv = &mbox->mchan[i];
 329                 mbox->irq_map_chan[i] = NULL;
 330
 331                 mbox->mchan[i].parent = mbox;
 332                 mbox->mchan[i].slot   = i;
 333         }
 334
 335         /* mask and clear all interrupt vectors */
 336         writel(0x0,  ACK_INT_MSK_REG(mbox->ipc));
 337         writel(~0x0, ACK_INT_CLR_REG(mbox->ipc));
 338
 339         /* use interrupt for tx's ack */
 340         if (of_find_property(node, "hi6220,mbox-tx-noirq", NULL))
 341                 mbox->tx_irq_mode = false;
 342         else
 343                 mbox->tx_irq_mode = true;
 344
 345         if (mbox->tx_irq_mode)
 346                 mbox->controller.txdone_irq = true;
 347         else {
 348                 mbox->controller.txdone_poll = true;
 349                 mbox->controller.txpoll_period = 5;
 350         }
 351
 352         err = mbox_controller_register(&mbox->controller);
 353         if (err) {
 354                 dev_err(dev, "Failed to register mailbox %d\n", err);
 355                 return err;
 356         }
 357
 358         platform_set_drvdata(pdev, mbox);
 359         dev_info(dev, "Mailbox enabled\n");
 360         return 0;
 361 }
 362
 363 static int hi6220_mbox_remove(struct platform_device *pdev)
 364 {
 365         struct hi6220_mbox *mbox = platform_get_drvdata(pdev);
 366
 367         mbox_controller_unregister(&mbox->controller);
 368         return 0;
 369 }
 370
 371 static struct platform_driver hi6220_mbox_driver = {
 372         .driver = {
 373                 .name = "hi6220-mbox",
 374                 .owner = THIS_MODULE,
 375                 .of_match_table = hi6220_mbox_of_match,
 376         },
 377         .probe  = hi6220_mbox_probe,
 378         .remove = hi6220_mbox_remove,
 379 };
 380
 381 static int __init hi6220_mbox_init(void)
 382 {
 383         return platform_driver_register(&hi6220_mbox_driver);
 384 }
 385 core_initcall(hi6220_mbox_init);
 386
 387 static void __exit hi6220_mbox_exit(void)
 388 {
 389         platform_driver_unregister(&hi6220_mbox_driver);
 390 }
 391 module_exit(hi6220_mbox_exit);
 392
 393 MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
 394 MODULE_DESCRIPTION("Hi6220 mailbox driver");
 395 MODULE_LICENSE("GPL v2");