1 // SPDX-License-Identifier: GPL-2.0-only 2 /* CAN bus driver for Microchip 251x/25625 CAN Controller with SPI Interface 3 * 4 * MCP2510 support and bug fixes by Christian Pellegrin 5 * <chripell@evolware.org> 6 * 7 * Copyright 2009 Christian Pellegrin EVOL S.r.l. 8 * 9 * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved. 10 * Written under contract by: 11 * Chris Elston, Katalix Systems, Ltd. 12 * 13 * Based on Microchip MCP251x CAN controller driver written by 14 * David Vrabel, Copyright 2006 Arcom Control Systems Ltd. 15 * 16 * Based on CAN bus driver for the CCAN controller written by 17 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix 18 * - Simon Kallweit, intefo AG 19 * Copyright 2007 20 */ 21 22 #include <linux/bitfield.h> 23 #include <linux/can/core.h> 24 #include <linux/can/dev.h> 25 #include <linux/clk.h> 26 #include <linux/completion.h> 27 #include <linux/delay.h> 28 #include <linux/device.h> 29 #include <linux/freezer.h> 30 #include <linux/gpio.h> 31 #include <linux/gpio/driver.h> 32 #include <linux/interrupt.h> 33 #include <linux/io.h> 34 #include <linux/iopoll.h> 35 #include <linux/kernel.h> 36 #include <linux/module.h> 37 #include <linux/netdevice.h> 38 #include <linux/platform_device.h> 39 #include <linux/property.h> 40 #include <linux/regulator/consumer.h> 41 #include <linux/slab.h> 42 #include <linux/spi/spi.h> 43 #include <linux/uaccess.h> 44 45 /* SPI interface instruction set */ 46 #define INSTRUCTION_WRITE 0x02 47 #define INSTRUCTION_READ 0x03 48 #define INSTRUCTION_BIT_MODIFY 0x05 49 #define INSTRUCTION_LOAD_TXB(n) (0x40 + 2 * (n)) 50 #define INSTRUCTION_READ_RXB(n) (((n) == 0) ? 0x90 : 0x94) 51 #define INSTRUCTION_RESET 0xC0 52 #define RTS_TXB0 0x01 53 #define RTS_TXB1 0x02 54 #define RTS_TXB2 0x04 55 #define INSTRUCTION_RTS(n) (0x80 | ((n) & 0x07)) 56 57 /* MPC251x registers */ 58 #define BFPCTRL 0x0c 59 # define BFPCTRL_B0BFM BIT(0) 60 # define BFPCTRL_B1BFM BIT(1) 61 # define BFPCTRL_BFM(n) (BFPCTRL_B0BFM << (n)) 62 # define BFPCTRL_BFM_MASK GENMASK(1, 0) 63 # define BFPCTRL_B0BFE BIT(2) 64 # define BFPCTRL_B1BFE BIT(3) 65 # define BFPCTRL_BFE(n) (BFPCTRL_B0BFE << (n)) 66 # define BFPCTRL_BFE_MASK GENMASK(3, 2) 67 # define BFPCTRL_B0BFS BIT(4) 68 # define BFPCTRL_B1BFS BIT(5) 69 # define BFPCTRL_BFS(n) (BFPCTRL_B0BFS << (n)) 70 # define BFPCTRL_BFS_MASK GENMASK(5, 4) 71 #define TXRTSCTRL 0x0d 72 # define TXRTSCTRL_B0RTSM BIT(0) 73 # define TXRTSCTRL_B1RTSM BIT(1) 74 # define TXRTSCTRL_B2RTSM BIT(2) 75 # define TXRTSCTRL_RTSM(n) (TXRTSCTRL_B0RTSM << (n)) 76 # define TXRTSCTRL_RTSM_MASK GENMASK(2, 0) 77 # define TXRTSCTRL_B0RTS BIT(3) 78 # define TXRTSCTRL_B1RTS BIT(4) 79 # define TXRTSCTRL_B2RTS BIT(5) 80 # define TXRTSCTRL_RTS(n) (TXRTSCTRL_B0RTS << (n)) 81 # define TXRTSCTRL_RTS_MASK GENMASK(5, 3) 82 #define CANSTAT 0x0e 83 #define CANCTRL 0x0f 84 # define CANCTRL_REQOP_MASK 0xe0 85 # define CANCTRL_REQOP_CONF 0x80 86 # define CANCTRL_REQOP_LISTEN_ONLY 0x60 87 # define CANCTRL_REQOP_LOOPBACK 0x40 88 # define CANCTRL_REQOP_SLEEP 0x20 89 # define CANCTRL_REQOP_NORMAL 0x00 90 # define CANCTRL_OSM 0x08 91 # define CANCTRL_ABAT 0x10 92 #define TEC 0x1c 93 #define REC 0x1d 94 #define CNF1 0x2a 95 # define CNF1_SJW_SHIFT 6 96 #define CNF2 0x29 97 # define CNF2_BTLMODE 0x80 98 # define CNF2_SAM 0x40 99 # define CNF2_PS1_SHIFT 3 100 #define CNF3 0x28 101 # define CNF3_SOF 0x08 102 # define CNF3_WAKFIL 0x04 103 # define CNF3_PHSEG2_MASK 0x07 104 #define CANINTE 0x2b 105 # define CANINTE_MERRE 0x80 106 # define CANINTE_WAKIE 0x40 107 # define CANINTE_ERRIE 0x20 108 # define CANINTE_TX2IE 0x10 109 # define CANINTE_TX1IE 0x08 110 # define CANINTE_TX0IE 0x04 111 # define CANINTE_RX1IE 0x02 112 # define CANINTE_RX0IE 0x01 113 #define CANINTF 0x2c 114 # define CANINTF_MERRF 0x80 115 # define CANINTF_WAKIF 0x40 116 # define CANINTF_ERRIF 0x20 117 # define CANINTF_TX2IF 0x10 118 # define CANINTF_TX1IF 0x08 119 # define CANINTF_TX0IF 0x04 120 # define CANINTF_RX1IF 0x02 121 # define CANINTF_RX0IF 0x01 122 # define CANINTF_RX (CANINTF_RX0IF | CANINTF_RX1IF) 123 # define CANINTF_TX (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF) 124 # define CANINTF_ERR (CANINTF_ERRIF) 125 #define EFLG 0x2d 126 # define EFLG_EWARN 0x01 127 # define EFLG_RXWAR 0x02 128 # define EFLG_TXWAR 0x04 129 # define EFLG_RXEP 0x08 130 # define EFLG_TXEP 0x10 131 # define EFLG_TXBO 0x20 132 # define EFLG_RX0OVR 0x40 133 # define EFLG_RX1OVR 0x80 134 #define TXBCTRL(n) (((n) * 0x10) + 0x30 + TXBCTRL_OFF) 135 # define TXBCTRL_ABTF 0x40 136 # define TXBCTRL_MLOA 0x20 137 # define TXBCTRL_TXERR 0x10 138 # define TXBCTRL_TXREQ 0x08 139 #define TXBSIDH(n) (((n) * 0x10) + 0x30 + TXBSIDH_OFF) 140 # define SIDH_SHIFT 3 141 #define TXBSIDL(n) (((n) * 0x10) + 0x30 + TXBSIDL_OFF) 142 # define SIDL_SID_MASK 7 143 # define SIDL_SID_SHIFT 5 144 # define SIDL_EXIDE_SHIFT 3 145 # define SIDL_EID_SHIFT 16 146 # define SIDL_EID_MASK 3 147 #define TXBEID8(n) (((n) * 0x10) + 0x30 + TXBEID8_OFF) 148 #define TXBEID0(n) (((n) * 0x10) + 0x30 + TXBEID0_OFF) 149 #define TXBDLC(n) (((n) * 0x10) + 0x30 + TXBDLC_OFF) 150 # define DLC_RTR_SHIFT 6 151 #define TXBCTRL_OFF 0 152 #define TXBSIDH_OFF 1 153 #define TXBSIDL_OFF 2 154 #define TXBEID8_OFF 3 155 #define TXBEID0_OFF 4 156 #define TXBDLC_OFF 5 157 #define TXBDAT_OFF 6 158 #define RXBCTRL(n) (((n) * 0x10) + 0x60 + RXBCTRL_OFF) 159 # define RXBCTRL_BUKT 0x04 160 # define RXBCTRL_RXM0 0x20 161 # define RXBCTRL_RXM1 0x40 162 #define RXBSIDH(n) (((n) * 0x10) + 0x60 + RXBSIDH_OFF) 163 # define RXBSIDH_SHIFT 3 164 #define RXBSIDL(n) (((n) * 0x10) + 0x60 + RXBSIDL_OFF) 165 # define RXBSIDL_IDE 0x08 166 # define RXBSIDL_SRR 0x10 167 # define RXBSIDL_EID 3 168 # define RXBSIDL_SHIFT 5 169 #define RXBEID8(n) (((n) * 0x10) + 0x60 + RXBEID8_OFF) 170 #define RXBEID0(n) (((n) * 0x10) + 0x60 + RXBEID0_OFF) 171 #define RXBDLC(n) (((n) * 0x10) + 0x60 + RXBDLC_OFF) 172 # define RXBDLC_LEN_MASK 0x0f 173 # define RXBDLC_RTR 0x40 174 #define RXBCTRL_OFF 0 175 #define RXBSIDH_OFF 1 176 #define RXBSIDL_OFF 2 177 #define RXBEID8_OFF 3 178 #define RXBEID0_OFF 4 179 #define RXBDLC_OFF 5 180 #define RXBDAT_OFF 6 181 #define RXFSID(n) ((n < 3) ? 0 : 4) 182 #define RXFSIDH(n) ((n) * 4 + RXFSID(n)) 183 #define RXFSIDL(n) ((n) * 4 + 1 + RXFSID(n)) 184 #define RXFEID8(n) ((n) * 4 + 2 + RXFSID(n)) 185 #define RXFEID0(n) ((n) * 4 + 3 + RXFSID(n)) 186 #define RXMSIDH(n) ((n) * 4 + 0x20) 187 #define RXMSIDL(n) ((n) * 4 + 0x21) 188 #define RXMEID8(n) ((n) * 4 + 0x22) 189 #define RXMEID0(n) ((n) * 4 + 0x23) 190 191 #define GET_BYTE(val, byte) \ 192 (((val) >> ((byte) * 8)) & 0xff) 193 #define SET_BYTE(val, byte) \ 194 (((val) & 0xff) << ((byte) * 8)) 195 196 /* Buffer size required for the largest SPI transfer (i.e., reading a 197 * frame) 198 */ 199 #define CAN_FRAME_MAX_DATA_LEN 8 200 #define SPI_TRANSFER_BUF_LEN (6 + CAN_FRAME_MAX_DATA_LEN) 201 #define CAN_FRAME_MAX_BITS 128 202 203 #define TX_ECHO_SKB_MAX 1 204 205 #define MCP251X_OST_DELAY_MS (5) 206 207 #define DEVICE_NAME "mcp251x" 208 209 static const struct can_bittiming_const mcp251x_bittiming_const = { 210 .name = DEVICE_NAME, 211 .tseg1_min = 3, 212 .tseg1_max = 16, 213 .tseg2_min = 2, 214 .tseg2_max = 8, 215 .sjw_max = 4, 216 .brp_min = 1, 217 .brp_max = 64, 218 .brp_inc = 1, 219 }; 220 221 enum mcp251x_model { 222 CAN_MCP251X_MCP2510 = 0x2510, 223 CAN_MCP251X_MCP2515 = 0x2515, 224 CAN_MCP251X_MCP25625 = 0x25625, 225 }; 226 227 struct mcp251x_priv { 228 struct can_priv can; 229 struct net_device *net; 230 struct spi_device *spi; 231 enum mcp251x_model model; 232 233 struct mutex mcp_lock; /* SPI device lock */ 234 235 u8 *spi_tx_buf; 236 u8 *spi_rx_buf; 237 238 struct sk_buff *tx_skb; 239 240 struct workqueue_struct *wq; 241 struct work_struct tx_work; 242 struct work_struct restart_work; 243 244 int force_quit; 245 int after_suspend; 246 #define AFTER_SUSPEND_UP 1 247 #define AFTER_SUSPEND_DOWN 2 248 #define AFTER_SUSPEND_POWER 4 249 #define AFTER_SUSPEND_RESTART 8 250 int restart_tx; 251 bool tx_busy; 252 253 struct regulator *power; 254 struct regulator *transceiver; 255 struct clk *clk; 256 #ifdef CONFIG_GPIOLIB 257 struct gpio_chip gpio; 258 u8 reg_bfpctrl; 259 #endif 260 }; 261 262 #define MCP251X_IS(_model) \ 263 static inline int mcp251x_is_##_model(struct spi_device *spi) \ 264 { \ 265 struct mcp251x_priv *priv = spi_get_drvdata(spi); \ 266 return priv->model == CAN_MCP251X_MCP##_model; \ 267 } 268 269 MCP251X_IS(2510); 270 271 static void mcp251x_clean(struct net_device *net) 272 { 273 struct mcp251x_priv *priv = netdev_priv(net); 274 275 if (priv->tx_skb || priv->tx_busy) 276 net->stats.tx_errors++; 277 dev_kfree_skb(priv->tx_skb); 278 if (priv->tx_busy) 279 can_free_echo_skb(priv->net, 0, NULL); 280 priv->tx_skb = NULL; 281 priv->tx_busy = false; 282 } 283 284 /* Note about handling of error return of mcp251x_spi_trans: accessing 285 * registers via SPI is not really different conceptually than using 286 * normal I/O assembler instructions, although it's much more 287 * complicated from a practical POV. So it's not advisable to always 288 * check the return value of this function. Imagine that every 289 * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0) 290 * error();", it would be a great mess (well there are some situation 291 * when exception handling C++ like could be useful after all). So we 292 * just check that transfers are OK at the beginning of our 293 * conversation with the chip and to avoid doing really nasty things 294 * (like injecting bogus packets in the network stack). 295 */ 296 static int mcp251x_spi_trans(struct spi_device *spi, int len) 297 { 298 struct mcp251x_priv *priv = spi_get_drvdata(spi); 299 struct spi_transfer t = { 300 .tx_buf = priv->spi_tx_buf, 301 .rx_buf = priv->spi_rx_buf, 302 .len = len, 303 .cs_change = 0, 304 }; 305 struct spi_message m; 306 int ret; 307 308 spi_message_init(&m); 309 spi_message_add_tail(&t, &m); 310 311 ret = spi_sync(spi, &m); 312 if (ret) 313 dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret); 314 return ret; 315 } 316 317 static int mcp251x_spi_write(struct spi_device *spi, int len) 318 { 319 struct mcp251x_priv *priv = spi_get_drvdata(spi); 320 int ret; 321 322 ret = spi_write(spi, priv->spi_tx_buf, len); 323 if (ret) 324 dev_err(&spi->dev, "spi write failed: ret = %d\n", ret); 325 326 return ret; 327 } 328 329 static u8 mcp251x_read_reg(struct spi_device *spi, u8 reg) 330 { 331 struct mcp251x_priv *priv = spi_get_drvdata(spi); 332 u8 val = 0; 333 334 priv->spi_tx_buf[0] = INSTRUCTION_READ; 335 priv->spi_tx_buf[1] = reg; 336 337 if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) { 338 spi_write_then_read(spi, priv->spi_tx_buf, 2, &val, 1); 339 } else { 340 mcp251x_spi_trans(spi, 3); 341 val = priv->spi_rx_buf[2]; 342 } 343 344 return val; 345 } 346 347 static void mcp251x_read_2regs(struct spi_device *spi, u8 reg, u8 *v1, u8 *v2) 348 { 349 struct mcp251x_priv *priv = spi_get_drvdata(spi); 350 351 priv->spi_tx_buf[0] = INSTRUCTION_READ; 352 priv->spi_tx_buf[1] = reg; 353 354 if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) { 355 u8 val[2] = { 0 }; 356 357 spi_write_then_read(spi, priv->spi_tx_buf, 2, val, 2); 358 *v1 = val[0]; 359 *v2 = val[1]; 360 } else { 361 mcp251x_spi_trans(spi, 4); 362 363 *v1 = priv->spi_rx_buf[2]; 364 *v2 = priv->spi_rx_buf[3]; 365 } 366 } 367 368 static void mcp251x_write_reg(struct spi_device *spi, u8 reg, u8 val) 369 { 370 struct mcp251x_priv *priv = spi_get_drvdata(spi); 371 372 priv->spi_tx_buf[0] = INSTRUCTION_WRITE; 373 priv->spi_tx_buf[1] = reg; 374 priv->spi_tx_buf[2] = val; 375 376 mcp251x_spi_write(spi, 3); 377 } 378 379 static void mcp251x_write_2regs(struct spi_device *spi, u8 reg, u8 v1, u8 v2) 380 { 381 struct mcp251x_priv *priv = spi_get_drvdata(spi); 382 383 priv->spi_tx_buf[0] = INSTRUCTION_WRITE; 384 priv->spi_tx_buf[1] = reg; 385 priv->spi_tx_buf[2] = v1; 386 priv->spi_tx_buf[3] = v2; 387 388 mcp251x_spi_write(spi, 4); 389 } 390 391 static void mcp251x_write_bits(struct spi_device *spi, u8 reg, 392 u8 mask, u8 val) 393 { 394 struct mcp251x_priv *priv = spi_get_drvdata(spi); 395 396 priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY; 397 priv->spi_tx_buf[1] = reg; 398 priv->spi_tx_buf[2] = mask; 399 priv->spi_tx_buf[3] = val; 400 401 mcp251x_spi_write(spi, 4); 402 } 403 404 static u8 mcp251x_read_stat(struct spi_device *spi) 405 { 406 return mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK; 407 } 408 409 #define mcp251x_read_stat_poll_timeout(addr, val, cond, delay_us, timeout_us) \ 410 readx_poll_timeout(mcp251x_read_stat, addr, val, cond, \ 411 delay_us, timeout_us) 412 413 #ifdef CONFIG_GPIOLIB 414 enum { 415 MCP251X_GPIO_TX0RTS = 0, /* inputs */ 416 MCP251X_GPIO_TX1RTS, 417 MCP251X_GPIO_TX2RTS, 418 MCP251X_GPIO_RX0BF, /* outputs */ 419 MCP251X_GPIO_RX1BF, 420 }; 421 422 #define MCP251X_GPIO_INPUT_MASK \ 423 GENMASK(MCP251X_GPIO_TX2RTS, MCP251X_GPIO_TX0RTS) 424 #define MCP251X_GPIO_OUTPUT_MASK \ 425 GENMASK(MCP251X_GPIO_RX1BF, MCP251X_GPIO_RX0BF) 426 427 static const char * const mcp251x_gpio_names[] = { 428 [MCP251X_GPIO_TX0RTS] = "TX0RTS", /* inputs */ 429 [MCP251X_GPIO_TX1RTS] = "TX1RTS", 430 [MCP251X_GPIO_TX2RTS] = "TX2RTS", 431 [MCP251X_GPIO_RX0BF] = "RX0BF", /* outputs */ 432 [MCP251X_GPIO_RX1BF] = "RX1BF", 433 }; 434 435 static inline bool mcp251x_gpio_is_input(unsigned int offset) 436 { 437 return offset <= MCP251X_GPIO_TX2RTS; 438 } 439 440 static int mcp251x_gpio_request(struct gpio_chip *chip, 441 unsigned int offset) 442 { 443 struct mcp251x_priv *priv = gpiochip_get_data(chip); 444 u8 val; 445 446 /* nothing to be done for inputs */ 447 if (mcp251x_gpio_is_input(offset)) 448 return 0; 449 450 val = BFPCTRL_BFE(offset - MCP251X_GPIO_RX0BF); 451 452 mutex_lock(&priv->mcp_lock); 453 mcp251x_write_bits(priv->spi, BFPCTRL, val, val); 454 mutex_unlock(&priv->mcp_lock); 455 456 priv->reg_bfpctrl |= val; 457 458 return 0; 459 } 460 461 static void mcp251x_gpio_free(struct gpio_chip *chip, 462 unsigned int offset) 463 { 464 struct mcp251x_priv *priv = gpiochip_get_data(chip); 465 u8 val; 466 467 /* nothing to be done for inputs */ 468 if (mcp251x_gpio_is_input(offset)) 469 return; 470 471 val = BFPCTRL_BFE(offset - MCP251X_GPIO_RX0BF); 472 473 mutex_lock(&priv->mcp_lock); 474 mcp251x_write_bits(priv->spi, BFPCTRL, val, 0); 475 mutex_unlock(&priv->mcp_lock); 476 477 priv->reg_bfpctrl &= ~val; 478 } 479 480 static int mcp251x_gpio_get_direction(struct gpio_chip *chip, 481 unsigned int offset) 482 { 483 if (mcp251x_gpio_is_input(offset)) 484 return GPIOF_DIR_IN; 485 486 return GPIOF_DIR_OUT; 487 } 488 489 static int mcp251x_gpio_get(struct gpio_chip *chip, unsigned int offset) 490 { 491 struct mcp251x_priv *priv = gpiochip_get_data(chip); 492 u8 reg, mask, val; 493 494 if (mcp251x_gpio_is_input(offset)) { 495 reg = TXRTSCTRL; 496 mask = TXRTSCTRL_RTS(offset); 497 } else { 498 reg = BFPCTRL; 499 mask = BFPCTRL_BFS(offset - MCP251X_GPIO_RX0BF); 500 } 501 502 mutex_lock(&priv->mcp_lock); 503 val = mcp251x_read_reg(priv->spi, reg); 504 mutex_unlock(&priv->mcp_lock); 505 506 return !!(val & mask); 507 } 508 509 static int mcp251x_gpio_get_multiple(struct gpio_chip *chip, 510 unsigned long *maskp, unsigned long *bitsp) 511 { 512 struct mcp251x_priv *priv = gpiochip_get_data(chip); 513 unsigned long bits = 0; 514 u8 val; 515 516 mutex_lock(&priv->mcp_lock); 517 if (maskp[0] & MCP251X_GPIO_INPUT_MASK) { 518 val = mcp251x_read_reg(priv->spi, TXRTSCTRL); 519 val = FIELD_GET(TXRTSCTRL_RTS_MASK, val); 520 bits |= FIELD_PREP(MCP251X_GPIO_INPUT_MASK, val); 521 } 522 if (maskp[0] & MCP251X_GPIO_OUTPUT_MASK) { 523 val = mcp251x_read_reg(priv->spi, BFPCTRL); 524 val = FIELD_GET(BFPCTRL_BFS_MASK, val); 525 bits |= FIELD_PREP(MCP251X_GPIO_OUTPUT_MASK, val); 526 } 527 mutex_unlock(&priv->mcp_lock); 528 529 bitsp[0] = bits; 530 return 0; 531 } 532 533 static void mcp251x_gpio_set(struct gpio_chip *chip, unsigned int offset, 534 int value) 535 { 536 struct mcp251x_priv *priv = gpiochip_get_data(chip); 537 u8 mask, val; 538 539 mask = BFPCTRL_BFS(offset - MCP251X_GPIO_RX0BF); 540 val = value ? mask : 0; 541 542 mutex_lock(&priv->mcp_lock); 543 mcp251x_write_bits(priv->spi, BFPCTRL, mask, val); 544 mutex_unlock(&priv->mcp_lock); 545 546 priv->reg_bfpctrl &= ~mask; 547 priv->reg_bfpctrl |= val; 548 } 549 550 static void 551 mcp251x_gpio_set_multiple(struct gpio_chip *chip, 552 unsigned long *maskp, unsigned long *bitsp) 553 { 554 struct mcp251x_priv *priv = gpiochip_get_data(chip); 555 u8 mask, val; 556 557 mask = FIELD_GET(MCP251X_GPIO_OUTPUT_MASK, maskp[0]); 558 mask = FIELD_PREP(BFPCTRL_BFS_MASK, mask); 559 560 val = FIELD_GET(MCP251X_GPIO_OUTPUT_MASK, bitsp[0]); 561 val = FIELD_PREP(BFPCTRL_BFS_MASK, val); 562 563 if (!mask) 564 return; 565 566 mutex_lock(&priv->mcp_lock); 567 mcp251x_write_bits(priv->spi, BFPCTRL, mask, val); 568 mutex_unlock(&priv->mcp_lock); 569 570 priv->reg_bfpctrl &= ~mask; 571 priv->reg_bfpctrl |= val; 572 } 573 574 static void mcp251x_gpio_restore(struct spi_device *spi) 575 { 576 struct mcp251x_priv *priv = spi_get_drvdata(spi); 577 578 mcp251x_write_reg(spi, BFPCTRL, priv->reg_bfpctrl); 579 } 580 581 static int mcp251x_gpio_setup(struct mcp251x_priv *priv) 582 { 583 struct gpio_chip *gpio = &priv->gpio; 584 585 if (!device_property_present(&priv->spi->dev, "gpio-controller")) 586 return 0; 587 588 /* gpiochip handles TX[0..2]RTS and RX[0..1]BF */ 589 gpio->label = priv->spi->modalias; 590 gpio->parent = &priv->spi->dev; 591 gpio->owner = THIS_MODULE; 592 gpio->request = mcp251x_gpio_request; 593 gpio->free = mcp251x_gpio_free; 594 gpio->get_direction = mcp251x_gpio_get_direction; 595 gpio->get = mcp251x_gpio_get; 596 gpio->get_multiple = mcp251x_gpio_get_multiple; 597 gpio->set = mcp251x_gpio_set; 598 gpio->set_multiple = mcp251x_gpio_set_multiple; 599 gpio->base = -1; 600 gpio->ngpio = ARRAY_SIZE(mcp251x_gpio_names); 601 gpio->names = mcp251x_gpio_names; 602 gpio->can_sleep = true; 603 604 return devm_gpiochip_add_data(&priv->spi->dev, gpio, priv); 605 } 606 #else 607 static inline void mcp251x_gpio_restore(struct spi_device *spi) 608 { 609 } 610 611 static inline int mcp251x_gpio_setup(struct mcp251x_priv *priv) 612 { 613 return 0; 614 } 615 #endif 616 617 static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf, 618 int len, int tx_buf_idx) 619 { 620 struct mcp251x_priv *priv = spi_get_drvdata(spi); 621 622 if (mcp251x_is_2510(spi)) { 623 int i; 624 625 for (i = 1; i < TXBDAT_OFF + len; i++) 626 mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i, 627 buf[i]); 628 } else { 629 memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len); 630 mcp251x_spi_write(spi, TXBDAT_OFF + len); 631 } 632 } 633 634 static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame, 635 int tx_buf_idx) 636 { 637 struct mcp251x_priv *priv = spi_get_drvdata(spi); 638 u32 sid, eid, exide, rtr; 639 u8 buf[SPI_TRANSFER_BUF_LEN]; 640 641 exide = (frame->can_id & CAN_EFF_FLAG) ? 1 : 0; /* Extended ID Enable */ 642 if (exide) 643 sid = (frame->can_id & CAN_EFF_MASK) >> 18; 644 else 645 sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */ 646 eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */ 647 rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */ 648 649 buf[TXBCTRL_OFF] = INSTRUCTION_LOAD_TXB(tx_buf_idx); 650 buf[TXBSIDH_OFF] = sid >> SIDH_SHIFT; 651 buf[TXBSIDL_OFF] = ((sid & SIDL_SID_MASK) << SIDL_SID_SHIFT) | 652 (exide << SIDL_EXIDE_SHIFT) | 653 ((eid >> SIDL_EID_SHIFT) & SIDL_EID_MASK); 654 buf[TXBEID8_OFF] = GET_BYTE(eid, 1); 655 buf[TXBEID0_OFF] = GET_BYTE(eid, 0); 656 buf[TXBDLC_OFF] = (rtr << DLC_RTR_SHIFT) | frame->len; 657 memcpy(buf + TXBDAT_OFF, frame->data, frame->len); 658 mcp251x_hw_tx_frame(spi, buf, frame->len, tx_buf_idx); 659 660 /* use INSTRUCTION_RTS, to avoid "repeated frame problem" */ 661 priv->spi_tx_buf[0] = INSTRUCTION_RTS(1 << tx_buf_idx); 662 mcp251x_spi_write(priv->spi, 1); 663 } 664 665 static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf, 666 int buf_idx) 667 { 668 struct mcp251x_priv *priv = spi_get_drvdata(spi); 669 670 if (mcp251x_is_2510(spi)) { 671 int i, len; 672 673 for (i = 1; i < RXBDAT_OFF; i++) 674 buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i); 675 676 len = can_cc_dlc2len(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK); 677 for (; i < (RXBDAT_OFF + len); i++) 678 buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i); 679 } else { 680 priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx); 681 if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) { 682 spi_write_then_read(spi, priv->spi_tx_buf, 1, 683 priv->spi_rx_buf, 684 SPI_TRANSFER_BUF_LEN); 685 memcpy(buf + 1, priv->spi_rx_buf, 686 SPI_TRANSFER_BUF_LEN - 1); 687 } else { 688 mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN); 689 memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN); 690 } 691 } 692 } 693 694 static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx) 695 { 696 struct mcp251x_priv *priv = spi_get_drvdata(spi); 697 struct sk_buff *skb; 698 struct can_frame *frame; 699 u8 buf[SPI_TRANSFER_BUF_LEN]; 700 701 skb = alloc_can_skb(priv->net, &frame); 702 if (!skb) { 703 dev_err(&spi->dev, "cannot allocate RX skb\n"); 704 priv->net->stats.rx_dropped++; 705 return; 706 } 707 708 mcp251x_hw_rx_frame(spi, buf, buf_idx); 709 if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) { 710 /* Extended ID format */ 711 frame->can_id = CAN_EFF_FLAG; 712 frame->can_id |= 713 /* Extended ID part */ 714 SET_BYTE(buf[RXBSIDL_OFF] & RXBSIDL_EID, 2) | 715 SET_BYTE(buf[RXBEID8_OFF], 1) | 716 SET_BYTE(buf[RXBEID0_OFF], 0) | 717 /* Standard ID part */ 718 (((buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) | 719 (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT)) << 18); 720 /* Remote transmission request */ 721 if (buf[RXBDLC_OFF] & RXBDLC_RTR) 722 frame->can_id |= CAN_RTR_FLAG; 723 } else { 724 /* Standard ID format */ 725 frame->can_id = 726 (buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) | 727 (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT); 728 if (buf[RXBSIDL_OFF] & RXBSIDL_SRR) 729 frame->can_id |= CAN_RTR_FLAG; 730 } 731 /* Data length */ 732 frame->len = can_cc_dlc2len(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK); 733 if (!(frame->can_id & CAN_RTR_FLAG)) { 734 memcpy(frame->data, buf + RXBDAT_OFF, frame->len); 735 736 priv->net->stats.rx_bytes += frame->len; 737 } 738 priv->net->stats.rx_packets++; 739 740 netif_rx(skb); 741 } 742 743 static void mcp251x_hw_sleep(struct spi_device *spi) 744 { 745 mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP); 746 } 747 748 /* May only be called when device is sleeping! */ 749 static int mcp251x_hw_wake(struct spi_device *spi) 750 { 751 u8 value; 752 int ret; 753 754 /* Force wakeup interrupt to wake device, but don't execute IST */ 755 disable_irq(spi->irq); 756 mcp251x_write_2regs(spi, CANINTE, CANINTE_WAKIE, CANINTF_WAKIF); 757 758 /* Wait for oscillator startup timer after wake up */ 759 mdelay(MCP251X_OST_DELAY_MS); 760 761 /* Put device into config mode */ 762 mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_CONF); 763 764 /* Wait for the device to enter config mode */ 765 ret = mcp251x_read_stat_poll_timeout(spi, value, value == CANCTRL_REQOP_CONF, 766 MCP251X_OST_DELAY_MS * 1000, 767 USEC_PER_SEC); 768 if (ret) { 769 dev_err(&spi->dev, "MCP251x didn't enter in config mode\n"); 770 return ret; 771 } 772 773 /* Disable and clear pending interrupts */ 774 mcp251x_write_2regs(spi, CANINTE, 0x00, 0x00); 775 enable_irq(spi->irq); 776 777 return 0; 778 } 779 780 static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb, 781 struct net_device *net) 782 { 783 struct mcp251x_priv *priv = netdev_priv(net); 784 struct spi_device *spi = priv->spi; 785 786 if (priv->tx_skb || priv->tx_busy) { 787 dev_warn(&spi->dev, "hard_xmit called while tx busy\n"); 788 return NETDEV_TX_BUSY; 789 } 790 791 if (can_dropped_invalid_skb(net, skb)) 792 return NETDEV_TX_OK; 793 794 netif_stop_queue(net); 795 priv->tx_skb = skb; 796 queue_work(priv->wq, &priv->tx_work); 797 798 return NETDEV_TX_OK; 799 } 800 801 static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode) 802 { 803 struct mcp251x_priv *priv = netdev_priv(net); 804 805 switch (mode) { 806 case CAN_MODE_START: 807 mcp251x_clean(net); 808 /* We have to delay work since SPI I/O may sleep */ 809 priv->can.state = CAN_STATE_ERROR_ACTIVE; 810 priv->restart_tx = 1; 811 if (priv->can.restart_ms == 0) 812 priv->after_suspend = AFTER_SUSPEND_RESTART; 813 queue_work(priv->wq, &priv->restart_work); 814 break; 815 default: 816 return -EOPNOTSUPP; 817 } 818 819 return 0; 820 } 821 822 static int mcp251x_set_normal_mode(struct spi_device *spi) 823 { 824 struct mcp251x_priv *priv = spi_get_drvdata(spi); 825 u8 value; 826 int ret; 827 828 /* Enable interrupts */ 829 mcp251x_write_reg(spi, CANINTE, 830 CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE | 831 CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE); 832 833 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { 834 /* Put device into loopback mode */ 835 mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK); 836 } else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) { 837 /* Put device into listen-only mode */ 838 mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY); 839 } else { 840 /* Put device into normal mode */ 841 mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL); 842 843 /* Wait for the device to enter normal mode */ 844 ret = mcp251x_read_stat_poll_timeout(spi, value, value == 0, 845 MCP251X_OST_DELAY_MS * 1000, 846 USEC_PER_SEC); 847 if (ret) { 848 dev_err(&spi->dev, "MCP251x didn't enter in normal mode\n"); 849 return ret; 850 } 851 } 852 priv->can.state = CAN_STATE_ERROR_ACTIVE; 853 return 0; 854 } 855 856 static int mcp251x_do_set_bittiming(struct net_device *net) 857 { 858 struct mcp251x_priv *priv = netdev_priv(net); 859 struct can_bittiming *bt = &priv->can.bittiming; 860 struct spi_device *spi = priv->spi; 861 862 mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) | 863 (bt->brp - 1)); 864 mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE | 865 (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ? 866 CNF2_SAM : 0) | 867 ((bt->phase_seg1 - 1) << CNF2_PS1_SHIFT) | 868 (bt->prop_seg - 1)); 869 mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK, 870 (bt->phase_seg2 - 1)); 871 dev_dbg(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n", 872 mcp251x_read_reg(spi, CNF1), 873 mcp251x_read_reg(spi, CNF2), 874 mcp251x_read_reg(spi, CNF3)); 875 876 return 0; 877 } 878 879 static int mcp251x_setup(struct net_device *net, struct spi_device *spi) 880 { 881 mcp251x_do_set_bittiming(net); 882 883 mcp251x_write_reg(spi, RXBCTRL(0), 884 RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1); 885 mcp251x_write_reg(spi, RXBCTRL(1), 886 RXBCTRL_RXM0 | RXBCTRL_RXM1); 887 return 0; 888 } 889 890 static int mcp251x_hw_reset(struct spi_device *spi) 891 { 892 struct mcp251x_priv *priv = spi_get_drvdata(spi); 893 u8 value; 894 int ret; 895 896 /* Wait for oscillator startup timer after power up */ 897 mdelay(MCP251X_OST_DELAY_MS); 898 899 priv->spi_tx_buf[0] = INSTRUCTION_RESET; 900 ret = mcp251x_spi_write(spi, 1); 901 if (ret) 902 return ret; 903 904 /* Wait for oscillator startup timer after reset */ 905 mdelay(MCP251X_OST_DELAY_MS); 906 907 /* Wait for reset to finish */ 908 ret = mcp251x_read_stat_poll_timeout(spi, value, value == CANCTRL_REQOP_CONF, 909 MCP251X_OST_DELAY_MS * 1000, 910 USEC_PER_SEC); 911 if (ret) 912 dev_err(&spi->dev, "MCP251x didn't enter in conf mode after reset\n"); 913 return ret; 914 } 915 916 static int mcp251x_hw_probe(struct spi_device *spi) 917 { 918 u8 ctrl; 919 int ret; 920 921 ret = mcp251x_hw_reset(spi); 922 if (ret) 923 return ret; 924 925 ctrl = mcp251x_read_reg(spi, CANCTRL); 926 927 dev_dbg(&spi->dev, "CANCTRL 0x%02x\n", ctrl); 928 929 /* Check for power up default value */ 930 if ((ctrl & 0x17) != 0x07) 931 return -ENODEV; 932 933 return 0; 934 } 935 936 static int mcp251x_power_enable(struct regulator *reg, int enable) 937 { 938 if (IS_ERR_OR_NULL(reg)) 939 return 0; 940 941 if (enable) 942 return regulator_enable(reg); 943 else 944 return regulator_disable(reg); 945 } 946 947 static int mcp251x_stop(struct net_device *net) 948 { 949 struct mcp251x_priv *priv = netdev_priv(net); 950 struct spi_device *spi = priv->spi; 951 952 close_candev(net); 953 954 priv->force_quit = 1; 955 free_irq(spi->irq, priv); 956 957 mutex_lock(&priv->mcp_lock); 958 959 /* Disable and clear pending interrupts */ 960 mcp251x_write_2regs(spi, CANINTE, 0x00, 0x00); 961 962 mcp251x_write_reg(spi, TXBCTRL(0), 0); 963 mcp251x_clean(net); 964 965 mcp251x_hw_sleep(spi); 966 967 mcp251x_power_enable(priv->transceiver, 0); 968 969 priv->can.state = CAN_STATE_STOPPED; 970 971 mutex_unlock(&priv->mcp_lock); 972 973 return 0; 974 } 975 976 static void mcp251x_error_skb(struct net_device *net, int can_id, int data1) 977 { 978 struct sk_buff *skb; 979 struct can_frame *frame; 980 981 skb = alloc_can_err_skb(net, &frame); 982 if (skb) { 983 frame->can_id |= can_id; 984 frame->data[1] = data1; 985 netif_rx(skb); 986 } else { 987 netdev_err(net, "cannot allocate error skb\n"); 988 } 989 } 990 991 static void mcp251x_tx_work_handler(struct work_struct *ws) 992 { 993 struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, 994 tx_work); 995 struct spi_device *spi = priv->spi; 996 struct net_device *net = priv->net; 997 struct can_frame *frame; 998 999 mutex_lock(&priv->mcp_lock); 1000 if (priv->tx_skb) { 1001 if (priv->can.state == CAN_STATE_BUS_OFF) { 1002 mcp251x_clean(net); 1003 } else { 1004 frame = (struct can_frame *)priv->tx_skb->data; 1005 1006 if (frame->len > CAN_FRAME_MAX_DATA_LEN) 1007 frame->len = CAN_FRAME_MAX_DATA_LEN; 1008 mcp251x_hw_tx(spi, frame, 0); 1009 priv->tx_busy = true; 1010 can_put_echo_skb(priv->tx_skb, net, 0, 0); 1011 priv->tx_skb = NULL; 1012 } 1013 } 1014 mutex_unlock(&priv->mcp_lock); 1015 } 1016 1017 static void mcp251x_restart_work_handler(struct work_struct *ws) 1018 { 1019 struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv, 1020 restart_work); 1021 struct spi_device *spi = priv->spi; 1022 struct net_device *net = priv->net; 1023 1024 mutex_lock(&priv->mcp_lock); 1025 if (priv->after_suspend) { 1026 if (priv->after_suspend & AFTER_SUSPEND_POWER) { 1027 mcp251x_hw_reset(spi); 1028 mcp251x_setup(net, spi); 1029 mcp251x_gpio_restore(spi); 1030 } else { 1031 mcp251x_hw_wake(spi); 1032 } 1033 priv->force_quit = 0; 1034 if (priv->after_suspend & AFTER_SUSPEND_RESTART) { 1035 mcp251x_set_normal_mode(spi); 1036 } else if (priv->after_suspend & AFTER_SUSPEND_UP) { 1037 netif_device_attach(net); 1038 mcp251x_clean(net); 1039 mcp251x_set_normal_mode(spi); 1040 netif_wake_queue(net); 1041 } else { 1042 mcp251x_hw_sleep(spi); 1043 } 1044 priv->after_suspend = 0; 1045 } 1046 1047 if (priv->restart_tx) { 1048 priv->restart_tx = 0; 1049 mcp251x_write_reg(spi, TXBCTRL(0), 0); 1050 mcp251x_clean(net); 1051 netif_wake_queue(net); 1052 mcp251x_error_skb(net, CAN_ERR_RESTARTED, 0); 1053 } 1054 mutex_unlock(&priv->mcp_lock); 1055 } 1056 1057 static irqreturn_t mcp251x_can_ist(int irq, void *dev_id) 1058 { 1059 struct mcp251x_priv *priv = dev_id; 1060 struct spi_device *spi = priv->spi; 1061 struct net_device *net = priv->net; 1062 1063 mutex_lock(&priv->mcp_lock); 1064 while (!priv->force_quit) { 1065 enum can_state new_state; 1066 u8 intf, eflag; 1067 u8 clear_intf = 0; 1068 int can_id = 0, data1 = 0; 1069 1070 mcp251x_read_2regs(spi, CANINTF, &intf, &eflag); 1071 1072 /* mask out flags we don't care about */ 1073 intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR; 1074 1075 /* receive buffer 0 */ 1076 if (intf & CANINTF_RX0IF) { 1077 mcp251x_hw_rx(spi, 0); 1078 /* Free one buffer ASAP 1079 * (The MCP2515/25625 does this automatically.) 1080 */ 1081 if (mcp251x_is_2510(spi)) 1082 mcp251x_write_bits(spi, CANINTF, 1083 CANINTF_RX0IF, 0x00); 1084 } 1085 1086 /* receive buffer 1 */ 1087 if (intf & CANINTF_RX1IF) { 1088 mcp251x_hw_rx(spi, 1); 1089 /* The MCP2515/25625 does this automatically. */ 1090 if (mcp251x_is_2510(spi)) 1091 clear_intf |= CANINTF_RX1IF; 1092 } 1093 1094 /* any error or tx interrupt we need to clear? */ 1095 if (intf & (CANINTF_ERR | CANINTF_TX)) 1096 clear_intf |= intf & (CANINTF_ERR | CANINTF_TX); 1097 if (clear_intf) 1098 mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00); 1099 1100 if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) 1101 mcp251x_write_bits(spi, EFLG, eflag, 0x00); 1102 1103 /* Update can state */ 1104 if (eflag & EFLG_TXBO) { 1105 new_state = CAN_STATE_BUS_OFF; 1106 can_id |= CAN_ERR_BUSOFF; 1107 } else if (eflag & EFLG_TXEP) { 1108 new_state = CAN_STATE_ERROR_PASSIVE; 1109 can_id |= CAN_ERR_CRTL; 1110 data1 |= CAN_ERR_CRTL_TX_PASSIVE; 1111 } else if (eflag & EFLG_RXEP) { 1112 new_state = CAN_STATE_ERROR_PASSIVE; 1113 can_id |= CAN_ERR_CRTL; 1114 data1 |= CAN_ERR_CRTL_RX_PASSIVE; 1115 } else if (eflag & EFLG_TXWAR) { 1116 new_state = CAN_STATE_ERROR_WARNING; 1117 can_id |= CAN_ERR_CRTL; 1118 data1 |= CAN_ERR_CRTL_TX_WARNING; 1119 } else if (eflag & EFLG_RXWAR) { 1120 new_state = CAN_STATE_ERROR_WARNING; 1121 can_id |= CAN_ERR_CRTL; 1122 data1 |= CAN_ERR_CRTL_RX_WARNING; 1123 } else { 1124 new_state = CAN_STATE_ERROR_ACTIVE; 1125 } 1126 1127 /* Update can state statistics */ 1128 switch (priv->can.state) { 1129 case CAN_STATE_ERROR_ACTIVE: 1130 if (new_state >= CAN_STATE_ERROR_WARNING && 1131 new_state <= CAN_STATE_BUS_OFF) 1132 priv->can.can_stats.error_warning++; 1133 fallthrough; 1134 case CAN_STATE_ERROR_WARNING: 1135 if (new_state >= CAN_STATE_ERROR_PASSIVE && 1136 new_state <= CAN_STATE_BUS_OFF) 1137 priv->can.can_stats.error_passive++; 1138 break; 1139 default: 1140 break; 1141 } 1142 priv->can.state = new_state; 1143 1144 if (intf & CANINTF_ERRIF) { 1145 /* Handle overflow counters */ 1146 if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) { 1147 if (eflag & EFLG_RX0OVR) { 1148 net->stats.rx_over_errors++; 1149 net->stats.rx_errors++; 1150 } 1151 if (eflag & EFLG_RX1OVR) { 1152 net->stats.rx_over_errors++; 1153 net->stats.rx_errors++; 1154 } 1155 can_id |= CAN_ERR_CRTL; 1156 data1 |= CAN_ERR_CRTL_RX_OVERFLOW; 1157 } 1158 mcp251x_error_skb(net, can_id, data1); 1159 } 1160 1161 if (priv->can.state == CAN_STATE_BUS_OFF) { 1162 if (priv->can.restart_ms == 0) { 1163 priv->force_quit = 1; 1164 priv->can.can_stats.bus_off++; 1165 can_bus_off(net); 1166 mcp251x_hw_sleep(spi); 1167 break; 1168 } 1169 } 1170 1171 if (intf == 0) 1172 break; 1173 1174 if (intf & CANINTF_TX) { 1175 if (priv->tx_busy) { 1176 net->stats.tx_packets++; 1177 net->stats.tx_bytes += can_get_echo_skb(net, 0, 1178 NULL); 1179 priv->tx_busy = false; 1180 } 1181 netif_wake_queue(net); 1182 } 1183 } 1184 mutex_unlock(&priv->mcp_lock); 1185 return IRQ_HANDLED; 1186 } 1187 1188 static int mcp251x_open(struct net_device *net) 1189 { 1190 struct mcp251x_priv *priv = netdev_priv(net); 1191 struct spi_device *spi = priv->spi; 1192 unsigned long flags = 0; 1193 int ret; 1194 1195 ret = open_candev(net); 1196 if (ret) { 1197 dev_err(&spi->dev, "unable to set initial baudrate!\n"); 1198 return ret; 1199 } 1200 1201 mutex_lock(&priv->mcp_lock); 1202 mcp251x_power_enable(priv->transceiver, 1); 1203 1204 priv->force_quit = 0; 1205 priv->tx_skb = NULL; 1206 priv->tx_busy = false; 1207 1208 if (!dev_fwnode(&spi->dev)) 1209 flags = IRQF_TRIGGER_FALLING; 1210 1211 ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist, 1212 flags | IRQF_ONESHOT, dev_name(&spi->dev), 1213 priv); 1214 if (ret) { 1215 dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq); 1216 goto out_close; 1217 } 1218 1219 ret = mcp251x_hw_wake(spi); 1220 if (ret) 1221 goto out_free_irq; 1222 ret = mcp251x_setup(net, spi); 1223 if (ret) 1224 goto out_free_irq; 1225 ret = mcp251x_set_normal_mode(spi); 1226 if (ret) 1227 goto out_free_irq; 1228 1229 netif_wake_queue(net); 1230 mutex_unlock(&priv->mcp_lock); 1231 1232 return 0; 1233 1234 out_free_irq: 1235 free_irq(spi->irq, priv); 1236 mcp251x_hw_sleep(spi); 1237 out_close: 1238 mcp251x_power_enable(priv->transceiver, 0); 1239 close_candev(net); 1240 mutex_unlock(&priv->mcp_lock); 1241 return ret; 1242 } 1243 1244 static const struct net_device_ops mcp251x_netdev_ops = { 1245 .ndo_open = mcp251x_open, 1246 .ndo_stop = mcp251x_stop, 1247 .ndo_start_xmit = mcp251x_hard_start_xmit, 1248 .ndo_change_mtu = can_change_mtu, 1249 }; 1250 1251 static const struct of_device_id mcp251x_of_match[] = { 1252 { 1253 .compatible = "microchip,mcp2510", 1254 .data = (void *)CAN_MCP251X_MCP2510, 1255 }, 1256 { 1257 .compatible = "microchip,mcp2515", 1258 .data = (void *)CAN_MCP251X_MCP2515, 1259 }, 1260 { 1261 .compatible = "microchip,mcp25625", 1262 .data = (void *)CAN_MCP251X_MCP25625, 1263 }, 1264 { } 1265 }; 1266 MODULE_DEVICE_TABLE(of, mcp251x_of_match); 1267 1268 static const struct spi_device_id mcp251x_id_table[] = { 1269 { 1270 .name = "mcp2510", 1271 .driver_data = (kernel_ulong_t)CAN_MCP251X_MCP2510, 1272 }, 1273 { 1274 .name = "mcp2515", 1275 .driver_data = (kernel_ulong_t)CAN_MCP251X_MCP2515, 1276 }, 1277 { 1278 .name = "mcp25625", 1279 .driver_data = (kernel_ulong_t)CAN_MCP251X_MCP25625, 1280 }, 1281 { } 1282 }; 1283 MODULE_DEVICE_TABLE(spi, mcp251x_id_table); 1284 1285 static int mcp251x_can_probe(struct spi_device *spi) 1286 { 1287 const void *match = device_get_match_data(&spi->dev); 1288 struct net_device *net; 1289 struct mcp251x_priv *priv; 1290 struct clk *clk; 1291 u32 freq; 1292 int ret; 1293 1294 clk = devm_clk_get_optional(&spi->dev, NULL); 1295 if (IS_ERR(clk)) 1296 return PTR_ERR(clk); 1297 1298 freq = clk_get_rate(clk); 1299 if (freq == 0) 1300 device_property_read_u32(&spi->dev, "clock-frequency", &freq); 1301 1302 /* Sanity check */ 1303 if (freq < 1000000 || freq > 25000000) 1304 return -ERANGE; 1305 1306 /* Allocate can/net device */ 1307 net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX); 1308 if (!net) 1309 return -ENOMEM; 1310 1311 ret = clk_prepare_enable(clk); 1312 if (ret) 1313 goto out_free; 1314 1315 net->netdev_ops = &mcp251x_netdev_ops; 1316 net->flags |= IFF_ECHO; 1317 1318 priv = netdev_priv(net); 1319 priv->can.bittiming_const = &mcp251x_bittiming_const; 1320 priv->can.do_set_mode = mcp251x_do_set_mode; 1321 priv->can.clock.freq = freq / 2; 1322 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | 1323 CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY; 1324 if (match) 1325 priv->model = (enum mcp251x_model)(uintptr_t)match; 1326 else 1327 priv->model = spi_get_device_id(spi)->driver_data; 1328 priv->net = net; 1329 priv->clk = clk; 1330 1331 spi_set_drvdata(spi, priv); 1332 1333 /* Configure the SPI bus */ 1334 spi->bits_per_word = 8; 1335 if (mcp251x_is_2510(spi)) 1336 spi->max_speed_hz = spi->max_speed_hz ? : 5 * 1000 * 1000; 1337 else 1338 spi->max_speed_hz = spi->max_speed_hz ? : 10 * 1000 * 1000; 1339 ret = spi_setup(spi); 1340 if (ret) 1341 goto out_clk; 1342 1343 priv->power = devm_regulator_get_optional(&spi->dev, "vdd"); 1344 priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver"); 1345 if ((PTR_ERR(priv->power) == -EPROBE_DEFER) || 1346 (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) { 1347 ret = -EPROBE_DEFER; 1348 goto out_clk; 1349 } 1350 1351 ret = mcp251x_power_enable(priv->power, 1); 1352 if (ret) 1353 goto out_clk; 1354 1355 priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM, 1356 0); 1357 if (!priv->wq) { 1358 ret = -ENOMEM; 1359 goto out_clk; 1360 } 1361 INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler); 1362 INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler); 1363 1364 priv->spi = spi; 1365 mutex_init(&priv->mcp_lock); 1366 1367 priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN, 1368 GFP_KERNEL); 1369 if (!priv->spi_tx_buf) { 1370 ret = -ENOMEM; 1371 goto error_probe; 1372 } 1373 1374 priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN, 1375 GFP_KERNEL); 1376 if (!priv->spi_rx_buf) { 1377 ret = -ENOMEM; 1378 goto error_probe; 1379 } 1380 1381 SET_NETDEV_DEV(net, &spi->dev); 1382 1383 /* Here is OK to not lock the MCP, no one knows about it yet */ 1384 ret = mcp251x_hw_probe(spi); 1385 if (ret) { 1386 if (ret == -ENODEV) 1387 dev_err(&spi->dev, "Cannot initialize MCP%x. Wrong wiring?\n", 1388 priv->model); 1389 goto error_probe; 1390 } 1391 1392 mcp251x_hw_sleep(spi); 1393 1394 ret = register_candev(net); 1395 if (ret) 1396 goto error_probe; 1397 1398 ret = mcp251x_gpio_setup(priv); 1399 if (ret) 1400 goto error_probe; 1401 1402 netdev_info(net, "MCP%x successfully initialized.\n", priv->model); 1403 return 0; 1404 1405 error_probe: 1406 destroy_workqueue(priv->wq); 1407 priv->wq = NULL; 1408 mcp251x_power_enable(priv->power, 0); 1409 1410 out_clk: 1411 clk_disable_unprepare(clk); 1412 1413 out_free: 1414 free_candev(net); 1415 1416 dev_err(&spi->dev, "Probe failed, err=%d\n", -ret); 1417 return ret; 1418 } 1419 1420 static void mcp251x_can_remove(struct spi_device *spi) 1421 { 1422 struct mcp251x_priv *priv = spi_get_drvdata(spi); 1423 struct net_device *net = priv->net; 1424 1425 unregister_candev(net); 1426 1427 mcp251x_power_enable(priv->power, 0); 1428 1429 destroy_workqueue(priv->wq); 1430 priv->wq = NULL; 1431 1432 clk_disable_unprepare(priv->clk); 1433 1434 free_candev(net); 1435 } 1436 1437 static int __maybe_unused mcp251x_can_suspend(struct device *dev) 1438 { 1439 struct spi_device *spi = to_spi_device(dev); 1440 struct mcp251x_priv *priv = spi_get_drvdata(spi); 1441 struct net_device *net = priv->net; 1442 1443 priv->force_quit = 1; 1444 disable_irq(spi->irq); 1445 /* Note: at this point neither IST nor workqueues are running. 1446 * open/stop cannot be called anyway so locking is not needed 1447 */ 1448 if (netif_running(net)) { 1449 netif_device_detach(net); 1450 1451 mcp251x_hw_sleep(spi); 1452 mcp251x_power_enable(priv->transceiver, 0); 1453 priv->after_suspend = AFTER_SUSPEND_UP; 1454 } else { 1455 priv->after_suspend = AFTER_SUSPEND_DOWN; 1456 } 1457 1458 mcp251x_power_enable(priv->power, 0); 1459 priv->after_suspend |= AFTER_SUSPEND_POWER; 1460 1461 return 0; 1462 } 1463 1464 static int __maybe_unused mcp251x_can_resume(struct device *dev) 1465 { 1466 struct spi_device *spi = to_spi_device(dev); 1467 struct mcp251x_priv *priv = spi_get_drvdata(spi); 1468 1469 if (priv->after_suspend & AFTER_SUSPEND_POWER) 1470 mcp251x_power_enable(priv->power, 1); 1471 if (priv->after_suspend & AFTER_SUSPEND_UP) 1472 mcp251x_power_enable(priv->transceiver, 1); 1473 1474 if (priv->after_suspend & (AFTER_SUSPEND_POWER | AFTER_SUSPEND_UP)) 1475 queue_work(priv->wq, &priv->restart_work); 1476 else 1477 priv->after_suspend = 0; 1478 1479 priv->force_quit = 0; 1480 enable_irq(spi->irq); 1481 return 0; 1482 } 1483 1484 static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops, mcp251x_can_suspend, 1485 mcp251x_can_resume); 1486 1487 static struct spi_driver mcp251x_can_driver = { 1488 .driver = { 1489 .name = DEVICE_NAME, 1490 .of_match_table = mcp251x_of_match, 1491 .pm = &mcp251x_can_pm_ops, 1492 }, 1493 .id_table = mcp251x_id_table, 1494 .probe = mcp251x_can_probe, 1495 .remove = mcp251x_can_remove, 1496 }; 1497 module_spi_driver(mcp251x_can_driver); 1498 1499 MODULE_AUTHOR("Chris Elston <celston@katalix.com>, " 1500 "Christian Pellegrin <chripell@evolware.org>"); 1501 MODULE_DESCRIPTION("Microchip 251x/25625 CAN driver"); 1502 MODULE_LICENSE("GPL v2"); 1503