drivers/mailbox/imx-mailbox.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2018 Pengutronix, Oleksij Rempel <o.rempel@pengutronix.de>
   4  */
   5
   6 #include <linux/clk.h>
   7 #include <linux/interrupt.h>
   8 #include <linux/io.h>
   9 #include <linux/kernel.h>
  10 #include <linux/mailbox_controller.h>
  11 #include <linux/module.h>
  12 #include <linux/of_device.h>
  13 #include <linux/slab.h>
  14
  15 #define IMX_MU_xSR_GIPn(x)      BIT(28 + (3 - (x)))
  16 #define IMX_MU_xSR_RFn(x)       BIT(24 + (3 - (x)))
  17 #define IMX_MU_xSR_TEn(x)       BIT(20 + (3 - (x)))
  18 #define IMX_MU_xSR_BRDIP        BIT(9)
  19
  20 /* General Purpose Interrupt Enable */
  21 #define IMX_MU_xCR_GIEn(x)      BIT(28 + (3 - (x)))
  22 /* Receive Interrupt Enable */
  23 #define IMX_MU_xCR_RIEn(x)      BIT(24 + (3 - (x)))
  24 /* Transmit Interrupt Enable */
  25 #define IMX_MU_xCR_TIEn(x)      BIT(20 + (3 - (x)))
  26 /* General Purpose Interrupt Request */
  27 #define IMX_MU_xCR_GIRn(x)      BIT(16 + (3 - (x)))
  28
  29 #define IMX_MU_CHANS            16
  30 #define IMX_MU_CHAN_NAME_SIZE   20
  31
  32 enum imx_mu_chan_type {
  33         IMX_MU_TYPE_TX,         /* Tx */
  34         IMX_MU_TYPE_RX,         /* Rx */
  35         IMX_MU_TYPE_TXDB,       /* Tx doorbell */
  36         IMX_MU_TYPE_RXDB,       /* Rx doorbell */
  37 };
  38
  39 struct imx_mu_dcfg {
  40         u32     xTR[4];         /* Transmit Registers */
  41         u32     xRR[4];         /* Receive Registers */
  42         u32     xSR;            /* Status Register */
  43         u32     xCR;            /* Control Register */
  44 };
  45
  46 struct imx_mu_con_priv {
  47         unsigned int            idx;
  48         char                    irq_desc[IMX_MU_CHAN_NAME_SIZE];
  49         enum imx_mu_chan_type   type;
  50         struct mbox_chan        *chan;
  51         struct tasklet_struct   txdb_tasklet;
  52 };
  53
  54 struct imx_mu_priv {
  55         struct device           *dev;
  56         void __iomem            *base;
  57         spinlock_t              xcr_lock; /* control register lock */
  58
  59         struct mbox_controller  mbox;
  60         struct mbox_chan        mbox_chans[IMX_MU_CHANS];
  61
  62         struct imx_mu_con_priv  con_priv[IMX_MU_CHANS];
  63         const struct imx_mu_dcfg        *dcfg;
  64         struct clk              *clk;
  65         int                     irq;
  66
  67         bool                    side_b;
  68 };
  69
  70 static const struct imx_mu_dcfg imx_mu_cfg_imx6sx = {
  71         .xTR    = {0x0, 0x4, 0x8, 0xc},
  72         .xRR    = {0x10, 0x14, 0x18, 0x1c},
  73         .xSR    = 0x20,
  74         .xCR    = 0x24,
  75 };
  76
  77 static const struct imx_mu_dcfg imx_mu_cfg_imx7ulp = {
  78         .xTR    = {0x20, 0x24, 0x28, 0x2c},
  79         .xRR    = {0x40, 0x44, 0x48, 0x4c},
  80         .xSR    = 0x60,
  81         .xCR    = 0x64,
  82 };
  83
  84 static struct imx_mu_priv *to_imx_mu_priv(struct mbox_controller *mbox)
  85 {
  86         return container_of(mbox, struct imx_mu_priv, mbox);
  87 }
  88
  89 static void imx_mu_write(struct imx_mu_priv *priv, u32 val, u32 offs)
  90 {
  91         iowrite32(val, priv->base + offs);
  92 }
  93
  94 static u32 imx_mu_read(struct imx_mu_priv *priv, u32 offs)
  95 {
  96         return ioread32(priv->base + offs);
  97 }
  98
  99 static u32 imx_mu_xcr_rmw(struct imx_mu_priv *priv, u32 set, u32 clr)
 100 {
 101         unsigned long flags;
 102         u32 val;
 103
 104         spin_lock_irqsave(&priv->xcr_lock, flags);
 105         val = imx_mu_read(priv, priv->dcfg->xCR);
 106         val &= ~clr;
 107         val |= set;
 108         imx_mu_write(priv, val, priv->dcfg->xCR);
 109         spin_unlock_irqrestore(&priv->xcr_lock, flags);
 110
 111         return val;
 112 }
 113
 114 static void imx_mu_txdb_tasklet(unsigned long data)
 115 {
 116         struct imx_mu_con_priv *cp = (struct imx_mu_con_priv *)data;
 117
 118         mbox_chan_txdone(cp->chan, 0);
 119 }
 120
 121 static irqreturn_t imx_mu_isr(int irq, void *p)
 122 {
 123         struct mbox_chan *chan = p;
 124         struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
 125         struct imx_mu_con_priv *cp = chan->con_priv;
 126         u32 val, ctrl, dat;
 127
 128         ctrl = imx_mu_read(priv, priv->dcfg->xCR);
 129         val = imx_mu_read(priv, priv->dcfg->xSR);
 130
 131         switch (cp->type) {
 132         case IMX_MU_TYPE_TX:
 133                 val &= IMX_MU_xSR_TEn(cp->idx) &
 134                         (ctrl & IMX_MU_xCR_TIEn(cp->idx));
 135                 break;
 136         case IMX_MU_TYPE_RX:
 137                 val &= IMX_MU_xSR_RFn(cp->idx) &
 138                         (ctrl & IMX_MU_xCR_RIEn(cp->idx));
 139                 break;
 140         case IMX_MU_TYPE_RXDB:
 141                 val &= IMX_MU_xSR_GIPn(cp->idx) &
 142                         (ctrl & IMX_MU_xCR_GIEn(cp->idx));
 143                 break;
 144         default:
 145                 break;
 146         }
 147
 148         if (!val)
 149                 return IRQ_NONE;
 150
 151         if (val == IMX_MU_xSR_TEn(cp->idx)) {
 152                 imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_TIEn(cp->idx));
 153                 mbox_chan_txdone(chan, 0);
 154         } else if (val == IMX_MU_xSR_RFn(cp->idx)) {
 155                 dat = imx_mu_read(priv, priv->dcfg->xRR[cp->idx]);
 156                 mbox_chan_received_data(chan, (void *)&dat);
 157         } else if (val == IMX_MU_xSR_GIPn(cp->idx)) {
 158                 imx_mu_write(priv, IMX_MU_xSR_GIPn(cp->idx), priv->dcfg->xSR);
 159                 mbox_chan_received_data(chan, NULL);
 160         } else {
 161                 dev_warn_ratelimited(priv->dev, "Not handled interrupt\n");
 162                 return IRQ_NONE;
 163         }
 164
 165         return IRQ_HANDLED;
 166 }
 167
 168 static int imx_mu_send_data(struct mbox_chan *chan, void *data)
 169 {
 170         struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
 171         struct imx_mu_con_priv *cp = chan->con_priv;
 172         u32 *arg = data;
 173
 174         switch (cp->type) {
 175         case IMX_MU_TYPE_TX:
 176                 imx_mu_write(priv, *arg, priv->dcfg->xTR[cp->idx]);
 177                 imx_mu_xcr_rmw(priv, IMX_MU_xCR_TIEn(cp->idx), 0);
 178                 break;
 179         case IMX_MU_TYPE_TXDB:
 180                 imx_mu_xcr_rmw(priv, IMX_MU_xCR_GIRn(cp->idx), 0);
 181                 tasklet_schedule(&cp->txdb_tasklet);
 182                 break;
 183         default:
 184                 dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
 185                 return -EINVAL;
 186         }
 187
 188         return 0;
 189 }
 190
 191 static int imx_mu_startup(struct mbox_chan *chan)
 192 {
 193         struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
 194         struct imx_mu_con_priv *cp = chan->con_priv;
 195         int ret;
 196
 197         if (cp->type == IMX_MU_TYPE_TXDB) {
 198                 /* Tx doorbell don't have ACK support */
 199                 tasklet_init(&cp->txdb_tasklet, imx_mu_txdb_tasklet,
 200                              (unsigned long)cp);
 201                 return 0;
 202         }
 203
 204         ret = request_irq(priv->irq, imx_mu_isr, IRQF_SHARED |
 205                           IRQF_NO_SUSPEND, cp->irq_desc, chan);
 206         if (ret) {
 207                 dev_err(priv->dev,
 208                         "Unable to acquire IRQ %d\n", priv->irq);
 209                 return ret;
 210         }
 211
 212         switch (cp->type) {
 213         case IMX_MU_TYPE_RX:
 214                 imx_mu_xcr_rmw(priv, IMX_MU_xCR_RIEn(cp->idx), 0);
 215                 break;
 216         case IMX_MU_TYPE_RXDB:
 217                 imx_mu_xcr_rmw(priv, IMX_MU_xCR_GIEn(cp->idx), 0);
 218                 break;
 219         default:
 220                 break;
 221         }
 222
 223         return 0;
 224 }
 225
 226 static void imx_mu_shutdown(struct mbox_chan *chan)
 227 {
 228         struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
 229         struct imx_mu_con_priv *cp = chan->con_priv;
 230
 231         if (cp->type == IMX_MU_TYPE_TXDB) {
 232                 tasklet_kill(&cp->txdb_tasklet);
 233                 return;
 234         }
 235
 236         switch (cp->type) {
 237         case IMX_MU_TYPE_TX:
 238                 imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_TIEn(cp->idx));
 239                 break;
 240         case IMX_MU_TYPE_RX:
 241                 imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_RIEn(cp->idx));
 242                 break;
 243         case IMX_MU_TYPE_RXDB:
 244                 imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_GIEn(cp->idx));
 245                 break;
 246         default:
 247                 break;
 248         }
 249
 250         free_irq(priv->irq, chan);
 251 }
 252
 253 static const struct mbox_chan_ops imx_mu_ops = {
 254         .send_data = imx_mu_send_data,
 255         .startup = imx_mu_startup,
 256         .shutdown = imx_mu_shutdown,
 257 };
 258
 259 static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox,
 260                                        const struct of_phandle_args *sp)
 261 {
 262         u32 type, idx, chan;
 263
 264         if (sp->args_count != 2) {
 265                 dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
 266                 return ERR_PTR(-EINVAL);
 267         }
 268
 269         type = sp->args[0]; /* channel type */
 270         idx = sp->args[1]; /* index */
 271         chan = type * 4 + idx;
 272
 273         if (chan >= mbox->num_chans) {
 274                 dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
 275                 return ERR_PTR(-EINVAL);
 276         }
 277
 278         return &mbox->chans[chan];
 279 }
 280
 281 static void imx_mu_init_generic(struct imx_mu_priv *priv)
 282 {
 283         if (priv->side_b)
 284                 return;
 285
 286         /* Set default MU configuration */
 287         imx_mu_write(priv, 0, priv->dcfg->xCR);
 288 }
 289
 290 static int imx_mu_probe(struct platform_device *pdev)
 291 {
 292         struct device *dev = &pdev->dev;
 293         struct device_node *np = dev->of_node;
 294         struct imx_mu_priv *priv;
 295         const struct imx_mu_dcfg *dcfg;
 296         unsigned int i;
 297         int ret;
 298
 299         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 300         if (!priv)
 301                 return -ENOMEM;
 302
 303         priv->dev = dev;
 304
 305         priv->base = devm_platform_ioremap_resource(pdev, 0);
 306         if (IS_ERR(priv->base))
 307                 return PTR_ERR(priv->base);
 308
 309         priv->irq = platform_get_irq(pdev, 0);
 310         if (priv->irq < 0)
 311                 return priv->irq;
 312
 313         dcfg = of_device_get_match_data(dev);
 314         if (!dcfg)
 315                 return -EINVAL;
 316         priv->dcfg = dcfg;
 317
 318         priv->clk = devm_clk_get(dev, NULL);
 319         if (IS_ERR(priv->clk)) {
 320                 if (PTR_ERR(priv->clk) != -ENOENT)
 321                         return PTR_ERR(priv->clk);
 322
 323                 priv->clk = NULL;
 324         }
 325
 326         ret = clk_prepare_enable(priv->clk);
 327         if (ret) {
 328                 dev_err(dev, "Failed to enable clock\n");
 329                 return ret;
 330         }
 331
 332         for (i = 0; i < IMX_MU_CHANS; i++) {
 333                 struct imx_mu_con_priv *cp = &priv->con_priv[i];
 334
 335                 cp->idx = i % 4;
 336                 cp->type = i >> 2;
 337                 cp->chan = &priv->mbox_chans[i];
 338                 priv->mbox_chans[i].con_priv = cp;
 339                 snprintf(cp->irq_desc, sizeof(cp->irq_desc),
 340                          "imx_mu_chan[%i-%i]", cp->type, cp->idx);
 341         }
 342
 343         priv->side_b = of_property_read_bool(np, "fsl,mu-side-b");
 344
 345         spin_lock_init(&priv->xcr_lock);
 346
 347         priv->mbox.dev = dev;
 348         priv->mbox.ops = &imx_mu_ops;
 349         priv->mbox.chans = priv->mbox_chans;
 350         priv->mbox.num_chans = IMX_MU_CHANS;
 351         priv->mbox.of_xlate = imx_mu_xlate;
 352         priv->mbox.txdone_irq = true;
 353
 354         platform_set_drvdata(pdev, priv);
 355
 356         imx_mu_init_generic(priv);
 357
 358         return devm_mbox_controller_register(dev, &priv->mbox);
 359 }
 360
 361 static int imx_mu_remove(struct platform_device *pdev)
 362 {
 363         struct imx_mu_priv *priv = platform_get_drvdata(pdev);
 364
 365         clk_disable_unprepare(priv->clk);
 366
 367         return 0;
 368 }
 369
 370 static const struct of_device_id imx_mu_dt_ids[] = {
 371         { .compatible = "fsl,imx7ulp-mu", .data = &imx_mu_cfg_imx7ulp },
 372         { .compatible = "fsl,imx6sx-mu", .data = &imx_mu_cfg_imx6sx },
 373         { },
 374 };
 375 MODULE_DEVICE_TABLE(of, imx_mu_dt_ids);
 376
 377 static struct platform_driver imx_mu_driver = {
 378         .probe          = imx_mu_probe,
 379         .remove         = imx_mu_remove,
 380         .driver = {
 381                 .name   = "imx_mu",
 382                 .of_match_table = imx_mu_dt_ids,
 383         },
 384 };
 385 module_platform_driver(imx_mu_driver);
 386
 387 MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>");
 388 MODULE_DESCRIPTION("Message Unit driver for i.MX");
 389 MODULE_LICENSE("GPL v2");