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 /* Transmit Register */ 16 #define IMX_MU_xTRn(x) (0x00 + 4 * (x)) 17 /* Receive Register */ 18 #define IMX_MU_xRRn(x) (0x10 + 4 * (x)) 19 /* Status Register */ 20 #define IMX_MU_xSR 0x20 21 #define IMX_MU_xSR_GIPn(x) BIT(28 + (3 - (x))) 22 #define IMX_MU_xSR_RFn(x) BIT(24 + (3 - (x))) 23 #define IMX_MU_xSR_TEn(x) BIT(20 + (3 - (x))) 24 #define IMX_MU_xSR_BRDIP BIT(9) 25 26 /* Control Register */ 27 #define IMX_MU_xCR 0x24 28 /* General Purpose Interrupt Enable */ 29 #define IMX_MU_xCR_GIEn(x) BIT(28 + (3 - (x))) 30 /* Receive Interrupt Enable */ 31 #define IMX_MU_xCR_RIEn(x) BIT(24 + (3 - (x))) 32 /* Transmit Interrupt Enable */ 33 #define IMX_MU_xCR_TIEn(x) BIT(20 + (3 - (x))) 34 /* General Purpose Interrupt Request */ 35 #define IMX_MU_xCR_GIRn(x) BIT(16 + (3 - (x))) 36 37 #define IMX_MU_CHANS 16 38 #define IMX_MU_CHAN_NAME_SIZE 20 39 40 enum imx_mu_chan_type { 41 IMX_MU_TYPE_TX, /* Tx */ 42 IMX_MU_TYPE_RX, /* Rx */ 43 IMX_MU_TYPE_TXDB, /* Tx doorbell */ 44 IMX_MU_TYPE_RXDB, /* Rx doorbell */ 45 }; 46 47 struct imx_mu_con_priv { 48 unsigned int idx; 49 char irq_desc[IMX_MU_CHAN_NAME_SIZE]; 50 enum imx_mu_chan_type type; 51 struct mbox_chan *chan; 52 struct tasklet_struct txdb_tasklet; 53 }; 54 55 struct imx_mu_priv { 56 struct device *dev; 57 void __iomem *base; 58 spinlock_t xcr_lock; /* control register lock */ 59 60 struct mbox_controller mbox; 61 struct mbox_chan mbox_chans[IMX_MU_CHANS]; 62 63 struct imx_mu_con_priv con_priv[IMX_MU_CHANS]; 64 struct clk *clk; 65 int irq; 66 67 bool side_b; 68 }; 69 70 static struct imx_mu_priv *to_imx_mu_priv(struct mbox_controller *mbox) 71 { 72 return container_of(mbox, struct imx_mu_priv, mbox); 73 } 74 75 static void imx_mu_write(struct imx_mu_priv *priv, u32 val, u32 offs) 76 { 77 iowrite32(val, priv->base + offs); 78 } 79 80 static u32 imx_mu_read(struct imx_mu_priv *priv, u32 offs) 81 { 82 return ioread32(priv->base + offs); 83 } 84 85 static u32 imx_mu_xcr_rmw(struct imx_mu_priv *priv, u32 set, u32 clr) 86 { 87 unsigned long flags; 88 u32 val; 89 90 spin_lock_irqsave(&priv->xcr_lock, flags); 91 val = imx_mu_read(priv, IMX_MU_xCR); 92 val &= ~clr; 93 val |= set; 94 imx_mu_write(priv, val, IMX_MU_xCR); 95 spin_unlock_irqrestore(&priv->xcr_lock, flags); 96 97 return val; 98 } 99 100 static void imx_mu_txdb_tasklet(unsigned long data) 101 { 102 struct imx_mu_con_priv *cp = (struct imx_mu_con_priv *)data; 103 104 mbox_chan_txdone(cp->chan, 0); 105 } 106 107 static irqreturn_t imx_mu_isr(int irq, void *p) 108 { 109 struct mbox_chan *chan = p; 110 struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); 111 struct imx_mu_con_priv *cp = chan->con_priv; 112 u32 val, ctrl, dat; 113 114 ctrl = imx_mu_read(priv, IMX_MU_xCR); 115 val = imx_mu_read(priv, IMX_MU_xSR); 116 117 switch (cp->type) { 118 case IMX_MU_TYPE_TX: 119 val &= IMX_MU_xSR_TEn(cp->idx) & 120 (ctrl & IMX_MU_xCR_TIEn(cp->idx)); 121 break; 122 case IMX_MU_TYPE_RX: 123 val &= IMX_MU_xSR_RFn(cp->idx) & 124 (ctrl & IMX_MU_xCR_RIEn(cp->idx)); 125 break; 126 case IMX_MU_TYPE_RXDB: 127 val &= IMX_MU_xSR_GIPn(cp->idx) & 128 (ctrl & IMX_MU_xCR_GIEn(cp->idx)); 129 break; 130 default: 131 break; 132 } 133 134 if (!val) 135 return IRQ_NONE; 136 137 if (val == IMX_MU_xSR_TEn(cp->idx)) { 138 imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_TIEn(cp->idx)); 139 mbox_chan_txdone(chan, 0); 140 } else if (val == IMX_MU_xSR_RFn(cp->idx)) { 141 dat = imx_mu_read(priv, IMX_MU_xRRn(cp->idx)); 142 mbox_chan_received_data(chan, (void *)&dat); 143 } else if (val == IMX_MU_xSR_GIPn(cp->idx)) { 144 imx_mu_write(priv, IMX_MU_xSR_GIPn(cp->idx), IMX_MU_xSR); 145 mbox_chan_received_data(chan, NULL); 146 } else { 147 dev_warn_ratelimited(priv->dev, "Not handled interrupt\n"); 148 return IRQ_NONE; 149 } 150 151 return IRQ_HANDLED; 152 } 153 154 static int imx_mu_send_data(struct mbox_chan *chan, void *data) 155 { 156 struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); 157 struct imx_mu_con_priv *cp = chan->con_priv; 158 u32 *arg = data; 159 160 switch (cp->type) { 161 case IMX_MU_TYPE_TX: 162 imx_mu_write(priv, *arg, IMX_MU_xTRn(cp->idx)); 163 imx_mu_xcr_rmw(priv, IMX_MU_xCR_TIEn(cp->idx), 0); 164 break; 165 case IMX_MU_TYPE_TXDB: 166 imx_mu_xcr_rmw(priv, IMX_MU_xCR_GIRn(cp->idx), 0); 167 tasklet_schedule(&cp->txdb_tasklet); 168 break; 169 default: 170 dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type); 171 return -EINVAL; 172 } 173 174 return 0; 175 } 176 177 static int imx_mu_startup(struct mbox_chan *chan) 178 { 179 struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); 180 struct imx_mu_con_priv *cp = chan->con_priv; 181 int ret; 182 183 if (cp->type == IMX_MU_TYPE_TXDB) { 184 /* Tx doorbell don't have ACK support */ 185 tasklet_init(&cp->txdb_tasklet, imx_mu_txdb_tasklet, 186 (unsigned long)cp); 187 return 0; 188 } 189 190 ret = request_irq(priv->irq, imx_mu_isr, IRQF_SHARED | 191 IRQF_NO_SUSPEND, cp->irq_desc, chan); 192 if (ret) { 193 dev_err(priv->dev, 194 "Unable to acquire IRQ %d\n", priv->irq); 195 return ret; 196 } 197 198 switch (cp->type) { 199 case IMX_MU_TYPE_RX: 200 imx_mu_xcr_rmw(priv, IMX_MU_xCR_RIEn(cp->idx), 0); 201 break; 202 case IMX_MU_TYPE_RXDB: 203 imx_mu_xcr_rmw(priv, IMX_MU_xCR_GIEn(cp->idx), 0); 204 break; 205 default: 206 break; 207 } 208 209 return 0; 210 } 211 212 static void imx_mu_shutdown(struct mbox_chan *chan) 213 { 214 struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox); 215 struct imx_mu_con_priv *cp = chan->con_priv; 216 217 if (cp->type == IMX_MU_TYPE_TXDB) 218 tasklet_kill(&cp->txdb_tasklet); 219 220 imx_mu_xcr_rmw(priv, 0, IMX_MU_xCR_TIEn(cp->idx) | 221 IMX_MU_xCR_RIEn(cp->idx) | IMX_MU_xCR_GIEn(cp->idx)); 222 223 free_irq(priv->irq, chan); 224 } 225 226 static const struct mbox_chan_ops imx_mu_ops = { 227 .send_data = imx_mu_send_data, 228 .startup = imx_mu_startup, 229 .shutdown = imx_mu_shutdown, 230 }; 231 232 static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox, 233 const struct of_phandle_args *sp) 234 { 235 u32 type, idx, chan; 236 237 if (sp->args_count != 2) { 238 dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count); 239 return ERR_PTR(-EINVAL); 240 } 241 242 type = sp->args[0]; /* channel type */ 243 idx = sp->args[1]; /* index */ 244 chan = type * 4 + idx; 245 246 if (chan >= mbox->num_chans) { 247 dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx); 248 return ERR_PTR(-EINVAL); 249 } 250 251 return &mbox->chans[chan]; 252 } 253 254 static void imx_mu_init_generic(struct imx_mu_priv *priv) 255 { 256 if (priv->side_b) 257 return; 258 259 /* Set default MU configuration */ 260 imx_mu_write(priv, 0, IMX_MU_xCR); 261 } 262 263 static int imx_mu_probe(struct platform_device *pdev) 264 { 265 struct device *dev = &pdev->dev; 266 struct device_node *np = dev->of_node; 267 struct imx_mu_priv *priv; 268 unsigned int i; 269 int ret; 270 271 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 272 if (!priv) 273 return -ENOMEM; 274 275 priv->dev = dev; 276 277 priv->base = devm_platform_ioremap_resource(pdev, 0); 278 if (IS_ERR(priv->base)) 279 return PTR_ERR(priv->base); 280 281 priv->irq = platform_get_irq(pdev, 0); 282 if (priv->irq < 0) 283 return priv->irq; 284 285 priv->clk = devm_clk_get(dev, NULL); 286 if (IS_ERR(priv->clk)) { 287 if (PTR_ERR(priv->clk) != -ENOENT) 288 return PTR_ERR(priv->clk); 289 290 priv->clk = NULL; 291 } 292 293 ret = clk_prepare_enable(priv->clk); 294 if (ret) { 295 dev_err(dev, "Failed to enable clock\n"); 296 return ret; 297 } 298 299 for (i = 0; i < IMX_MU_CHANS; i++) { 300 struct imx_mu_con_priv *cp = &priv->con_priv[i]; 301 302 cp->idx = i % 4; 303 cp->type = i >> 2; 304 cp->chan = &priv->mbox_chans[i]; 305 priv->mbox_chans[i].con_priv = cp; 306 snprintf(cp->irq_desc, sizeof(cp->irq_desc), 307 "imx_mu_chan[%i-%i]", cp->type, cp->idx); 308 } 309 310 priv->side_b = of_property_read_bool(np, "fsl,mu-side-b"); 311 312 spin_lock_init(&priv->xcr_lock); 313 314 priv->mbox.dev = dev; 315 priv->mbox.ops = &imx_mu_ops; 316 priv->mbox.chans = priv->mbox_chans; 317 priv->mbox.num_chans = IMX_MU_CHANS; 318 priv->mbox.of_xlate = imx_mu_xlate; 319 priv->mbox.txdone_irq = true; 320 321 platform_set_drvdata(pdev, priv); 322 323 imx_mu_init_generic(priv); 324 325 return devm_mbox_controller_register(dev, &priv->mbox); 326 } 327 328 static int imx_mu_remove(struct platform_device *pdev) 329 { 330 struct imx_mu_priv *priv = platform_get_drvdata(pdev); 331 332 clk_disable_unprepare(priv->clk); 333 334 return 0; 335 } 336 337 static const struct of_device_id imx_mu_dt_ids[] = { 338 { .compatible = "fsl,imx6sx-mu" }, 339 { }, 340 }; 341 MODULE_DEVICE_TABLE(of, imx_mu_dt_ids); 342 343 static struct platform_driver imx_mu_driver = { 344 .probe = imx_mu_probe, 345 .remove = imx_mu_remove, 346 .driver = { 347 .name = "imx_mu", 348 .of_match_table = imx_mu_dt_ids, 349 }, 350 }; 351 module_platform_driver(imx_mu_driver); 352 353 MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>"); 354 MODULE_DESCRIPTION("Message Unit driver for i.MX"); 355 MODULE_LICENSE("GPL v2"); 356