Linux Audio

Check our new training course

Open-source upstreaming

Need help get the support for your hardware in upstream Linux?
Loading...
Note: File does not exist in v3.15.
   1// SPDX-License-Identifier: GPL-2.0
   2// CAN bus driver for Bosch M_CAN controller
   3// Copyright (C) 2014 Freescale Semiconductor, Inc.
   4//      Dong Aisheng <b29396@freescale.com>
   5// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
   6
   7/* Bosch M_CAN user manual can be obtained from:
   8 * https://github.com/linux-can/can-doc/tree/master/m_can
   9 */
  10
  11#include <linux/bitfield.h>
  12#include <linux/can/dev.h>
  13#include <linux/ethtool.h>
  14#include <linux/hrtimer.h>
  15#include <linux/interrupt.h>
  16#include <linux/io.h>
  17#include <linux/iopoll.h>
  18#include <linux/kernel.h>
  19#include <linux/module.h>
  20#include <linux/netdevice.h>
  21#include <linux/of.h>
  22#include <linux/phy/phy.h>
  23#include <linux/pinctrl/consumer.h>
  24#include <linux/platform_device.h>
  25#include <linux/pm_runtime.h>
  26
  27#include "m_can.h"
  28
  29/* registers definition */
  30enum m_can_reg {
  31	M_CAN_CREL	= 0x0,
  32	M_CAN_ENDN	= 0x4,
  33	M_CAN_CUST	= 0x8,
  34	M_CAN_DBTP	= 0xc,
  35	M_CAN_TEST	= 0x10,
  36	M_CAN_RWD	= 0x14,
  37	M_CAN_CCCR	= 0x18,
  38	M_CAN_NBTP	= 0x1c,
  39	M_CAN_TSCC	= 0x20,
  40	M_CAN_TSCV	= 0x24,
  41	M_CAN_TOCC	= 0x28,
  42	M_CAN_TOCV	= 0x2c,
  43	M_CAN_ECR	= 0x40,
  44	M_CAN_PSR	= 0x44,
  45	/* TDCR Register only available for version >=3.1.x */
  46	M_CAN_TDCR	= 0x48,
  47	M_CAN_IR	= 0x50,
  48	M_CAN_IE	= 0x54,
  49	M_CAN_ILS	= 0x58,
  50	M_CAN_ILE	= 0x5c,
  51	M_CAN_GFC	= 0x80,
  52	M_CAN_SIDFC	= 0x84,
  53	M_CAN_XIDFC	= 0x88,
  54	M_CAN_XIDAM	= 0x90,
  55	M_CAN_HPMS	= 0x94,
  56	M_CAN_NDAT1	= 0x98,
  57	M_CAN_NDAT2	= 0x9c,
  58	M_CAN_RXF0C	= 0xa0,
  59	M_CAN_RXF0S	= 0xa4,
  60	M_CAN_RXF0A	= 0xa8,
  61	M_CAN_RXBC	= 0xac,
  62	M_CAN_RXF1C	= 0xb0,
  63	M_CAN_RXF1S	= 0xb4,
  64	M_CAN_RXF1A	= 0xb8,
  65	M_CAN_RXESC	= 0xbc,
  66	M_CAN_TXBC	= 0xc0,
  67	M_CAN_TXFQS	= 0xc4,
  68	M_CAN_TXESC	= 0xc8,
  69	M_CAN_TXBRP	= 0xcc,
  70	M_CAN_TXBAR	= 0xd0,
  71	M_CAN_TXBCR	= 0xd4,
  72	M_CAN_TXBTO	= 0xd8,
  73	M_CAN_TXBCF	= 0xdc,
  74	M_CAN_TXBTIE	= 0xe0,
  75	M_CAN_TXBCIE	= 0xe4,
  76	M_CAN_TXEFC	= 0xf0,
  77	M_CAN_TXEFS	= 0xf4,
  78	M_CAN_TXEFA	= 0xf8,
  79};
  80
  81/* message ram configuration data length */
  82#define MRAM_CFG_LEN	8
  83
  84/* Core Release Register (CREL) */
  85#define CREL_REL_MASK		GENMASK(31, 28)
  86#define CREL_STEP_MASK		GENMASK(27, 24)
  87#define CREL_SUBSTEP_MASK	GENMASK(23, 20)
  88
  89/* Data Bit Timing & Prescaler Register (DBTP) */
  90#define DBTP_TDC		BIT(23)
  91#define DBTP_DBRP_MASK		GENMASK(20, 16)
  92#define DBTP_DTSEG1_MASK	GENMASK(12, 8)
  93#define DBTP_DTSEG2_MASK	GENMASK(7, 4)
  94#define DBTP_DSJW_MASK		GENMASK(3, 0)
  95
  96/* Transmitter Delay Compensation Register (TDCR) */
  97#define TDCR_TDCO_MASK		GENMASK(14, 8)
  98#define TDCR_TDCF_MASK		GENMASK(6, 0)
  99
 100/* Test Register (TEST) */
 101#define TEST_LBCK		BIT(4)
 102
 103/* CC Control Register (CCCR) */
 104#define CCCR_TXP		BIT(14)
 105#define CCCR_TEST		BIT(7)
 106#define CCCR_DAR		BIT(6)
 107#define CCCR_MON		BIT(5)
 108#define CCCR_CSR		BIT(4)
 109#define CCCR_CSA		BIT(3)
 110#define CCCR_ASM		BIT(2)
 111#define CCCR_CCE		BIT(1)
 112#define CCCR_INIT		BIT(0)
 113/* for version 3.0.x */
 114#define CCCR_CMR_MASK		GENMASK(11, 10)
 115#define CCCR_CMR_CANFD		0x1
 116#define CCCR_CMR_CANFD_BRS	0x2
 117#define CCCR_CMR_CAN		0x3
 118#define CCCR_CME_MASK		GENMASK(9, 8)
 119#define CCCR_CME_CAN		0
 120#define CCCR_CME_CANFD		0x1
 121#define CCCR_CME_CANFD_BRS	0x2
 122/* for version >=3.1.x */
 123#define CCCR_EFBI		BIT(13)
 124#define CCCR_PXHD		BIT(12)
 125#define CCCR_BRSE		BIT(9)
 126#define CCCR_FDOE		BIT(8)
 127/* for version >=3.2.x */
 128#define CCCR_NISO		BIT(15)
 129/* for version >=3.3.x */
 130#define CCCR_WMM		BIT(11)
 131#define CCCR_UTSU		BIT(10)
 132
 133/* Nominal Bit Timing & Prescaler Register (NBTP) */
 134#define NBTP_NSJW_MASK		GENMASK(31, 25)
 135#define NBTP_NBRP_MASK		GENMASK(24, 16)
 136#define NBTP_NTSEG1_MASK	GENMASK(15, 8)
 137#define NBTP_NTSEG2_MASK	GENMASK(6, 0)
 138
 139/* Timestamp Counter Configuration Register (TSCC) */
 140#define TSCC_TCP_MASK		GENMASK(19, 16)
 141#define TSCC_TSS_MASK		GENMASK(1, 0)
 142#define TSCC_TSS_DISABLE	0x0
 143#define TSCC_TSS_INTERNAL	0x1
 144#define TSCC_TSS_EXTERNAL	0x2
 145
 146/* Timestamp Counter Value Register (TSCV) */
 147#define TSCV_TSC_MASK		GENMASK(15, 0)
 148
 149/* Error Counter Register (ECR) */
 150#define ECR_RP			BIT(15)
 151#define ECR_REC_MASK		GENMASK(14, 8)
 152#define ECR_TEC_MASK		GENMASK(7, 0)
 153
 154/* Protocol Status Register (PSR) */
 155#define PSR_BO		BIT(7)
 156#define PSR_EW		BIT(6)
 157#define PSR_EP		BIT(5)
 158#define PSR_LEC_MASK	GENMASK(2, 0)
 159#define PSR_DLEC_MASK	GENMASK(10, 8)
 160
 161/* Interrupt Register (IR) */
 162#define IR_ALL_INT	0xffffffff
 163
 164/* Renamed bits for versions > 3.1.x */
 165#define IR_ARA		BIT(29)
 166#define IR_PED		BIT(28)
 167#define IR_PEA		BIT(27)
 168
 169/* Bits for version 3.0.x */
 170#define IR_STE		BIT(31)
 171#define IR_FOE		BIT(30)
 172#define IR_ACKE		BIT(29)
 173#define IR_BE		BIT(28)
 174#define IR_CRCE		BIT(27)
 175#define IR_WDI		BIT(26)
 176#define IR_BO		BIT(25)
 177#define IR_EW		BIT(24)
 178#define IR_EP		BIT(23)
 179#define IR_ELO		BIT(22)
 180#define IR_BEU		BIT(21)
 181#define IR_BEC		BIT(20)
 182#define IR_DRX		BIT(19)
 183#define IR_TOO		BIT(18)
 184#define IR_MRAF		BIT(17)
 185#define IR_TSW		BIT(16)
 186#define IR_TEFL		BIT(15)
 187#define IR_TEFF		BIT(14)
 188#define IR_TEFW		BIT(13)
 189#define IR_TEFN		BIT(12)
 190#define IR_TFE		BIT(11)
 191#define IR_TCF		BIT(10)
 192#define IR_TC		BIT(9)
 193#define IR_HPM		BIT(8)
 194#define IR_RF1L		BIT(7)
 195#define IR_RF1F		BIT(6)
 196#define IR_RF1W		BIT(5)
 197#define IR_RF1N		BIT(4)
 198#define IR_RF0L		BIT(3)
 199#define IR_RF0F		BIT(2)
 200#define IR_RF0W		BIT(1)
 201#define IR_RF0N		BIT(0)
 202#define IR_ERR_STATE	(IR_BO | IR_EW | IR_EP)
 203
 204/* Interrupts for version 3.0.x */
 205#define IR_ERR_LEC_30X	(IR_STE	| IR_FOE | IR_ACKE | IR_BE | IR_CRCE)
 206#define IR_ERR_BUS_30X	(IR_ERR_LEC_30X | IR_WDI | IR_BEU | IR_BEC | \
 207			 IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | IR_RF1L | \
 208			 IR_RF0L)
 209#define IR_ERR_ALL_30X	(IR_ERR_STATE | IR_ERR_BUS_30X)
 210
 211/* Interrupts for version >= 3.1.x */
 212#define IR_ERR_LEC_31X	(IR_PED | IR_PEA)
 213#define IR_ERR_BUS_31X	(IR_ERR_LEC_31X | IR_WDI | IR_BEU | IR_BEC | \
 214			 IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | IR_RF1L | \
 215			 IR_RF0L)
 216#define IR_ERR_ALL_31X	(IR_ERR_STATE | IR_ERR_BUS_31X)
 217
 218/* Interrupt Line Select (ILS) */
 219#define ILS_ALL_INT0	0x0
 220#define ILS_ALL_INT1	0xFFFFFFFF
 221
 222/* Interrupt Line Enable (ILE) */
 223#define ILE_EINT1	BIT(1)
 224#define ILE_EINT0	BIT(0)
 225
 226/* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */
 227#define RXFC_FWM_MASK	GENMASK(30, 24)
 228#define RXFC_FS_MASK	GENMASK(22, 16)
 229
 230/* Rx FIFO 0/1 Status (RXF0S/RXF1S) */
 231#define RXFS_RFL	BIT(25)
 232#define RXFS_FF		BIT(24)
 233#define RXFS_FPI_MASK	GENMASK(21, 16)
 234#define RXFS_FGI_MASK	GENMASK(13, 8)
 235#define RXFS_FFL_MASK	GENMASK(6, 0)
 236
 237/* Rx Buffer / FIFO Element Size Configuration (RXESC) */
 238#define RXESC_RBDS_MASK		GENMASK(10, 8)
 239#define RXESC_F1DS_MASK		GENMASK(6, 4)
 240#define RXESC_F0DS_MASK		GENMASK(2, 0)
 241#define RXESC_64B		0x7
 242
 243/* Tx Buffer Configuration (TXBC) */
 244#define TXBC_TFQS_MASK		GENMASK(29, 24)
 245#define TXBC_NDTB_MASK		GENMASK(21, 16)
 246
 247/* Tx FIFO/Queue Status (TXFQS) */
 248#define TXFQS_TFQF		BIT(21)
 249#define TXFQS_TFQPI_MASK	GENMASK(20, 16)
 250#define TXFQS_TFGI_MASK		GENMASK(12, 8)
 251#define TXFQS_TFFL_MASK		GENMASK(5, 0)
 252
 253/* Tx Buffer Element Size Configuration (TXESC) */
 254#define TXESC_TBDS_MASK		GENMASK(2, 0)
 255#define TXESC_TBDS_64B		0x7
 256
 257/* Tx Event FIFO Configuration (TXEFC) */
 258#define TXEFC_EFS_MASK		GENMASK(21, 16)
 259
 260/* Tx Event FIFO Status (TXEFS) */
 261#define TXEFS_TEFL		BIT(25)
 262#define TXEFS_EFF		BIT(24)
 263#define TXEFS_EFGI_MASK		GENMASK(12, 8)
 264#define TXEFS_EFFL_MASK		GENMASK(5, 0)
 265
 266/* Tx Event FIFO Acknowledge (TXEFA) */
 267#define TXEFA_EFAI_MASK		GENMASK(4, 0)
 268
 269/* Message RAM Configuration (in bytes) */
 270#define SIDF_ELEMENT_SIZE	4
 271#define XIDF_ELEMENT_SIZE	8
 272#define RXF0_ELEMENT_SIZE	72
 273#define RXF1_ELEMENT_SIZE	72
 274#define RXB_ELEMENT_SIZE	72
 275#define TXE_ELEMENT_SIZE	8
 276#define TXB_ELEMENT_SIZE	72
 277
 278/* Message RAM Elements */
 279#define M_CAN_FIFO_ID		0x0
 280#define M_CAN_FIFO_DLC		0x4
 281#define M_CAN_FIFO_DATA		0x8
 282
 283/* Rx Buffer Element */
 284/* R0 */
 285#define RX_BUF_ESI		BIT(31)
 286#define RX_BUF_XTD		BIT(30)
 287#define RX_BUF_RTR		BIT(29)
 288/* R1 */
 289#define RX_BUF_ANMF		BIT(31)
 290#define RX_BUF_FDF		BIT(21)
 291#define RX_BUF_BRS		BIT(20)
 292#define RX_BUF_RXTS_MASK	GENMASK(15, 0)
 293
 294/* Tx Buffer Element */
 295/* T0 */
 296#define TX_BUF_ESI		BIT(31)
 297#define TX_BUF_XTD		BIT(30)
 298#define TX_BUF_RTR		BIT(29)
 299/* T1 */
 300#define TX_BUF_EFC		BIT(23)
 301#define TX_BUF_FDF		BIT(21)
 302#define TX_BUF_BRS		BIT(20)
 303#define TX_BUF_MM_MASK		GENMASK(31, 24)
 304#define TX_BUF_DLC_MASK		GENMASK(19, 16)
 305
 306/* Tx event FIFO Element */
 307/* E1 */
 308#define TX_EVENT_MM_MASK	GENMASK(31, 24)
 309#define TX_EVENT_TXTS_MASK	GENMASK(15, 0)
 310
 311/* Hrtimer polling interval */
 312#define HRTIMER_POLL_INTERVAL_MS		1
 313
 314/* The ID and DLC registers are adjacent in M_CAN FIFO memory,
 315 * and we can save a (potentially slow) bus round trip by combining
 316 * reads and writes to them.
 317 */
 318struct id_and_dlc {
 319	u32 id;
 320	u32 dlc;
 321};
 322
 323static inline u32 m_can_read(struct m_can_classdev *cdev, enum m_can_reg reg)
 324{
 325	return cdev->ops->read_reg(cdev, reg);
 326}
 327
 328static inline void m_can_write(struct m_can_classdev *cdev, enum m_can_reg reg,
 329			       u32 val)
 330{
 331	cdev->ops->write_reg(cdev, reg, val);
 332}
 333
 334static int
 335m_can_fifo_read(struct m_can_classdev *cdev,
 336		u32 fgi, unsigned int offset, void *val, size_t val_count)
 337{
 338	u32 addr_offset = cdev->mcfg[MRAM_RXF0].off + fgi * RXF0_ELEMENT_SIZE +
 339		offset;
 340
 341	if (val_count == 0)
 342		return 0;
 343
 344	return cdev->ops->read_fifo(cdev, addr_offset, val, val_count);
 345}
 346
 347static int
 348m_can_fifo_write(struct m_can_classdev *cdev,
 349		 u32 fpi, unsigned int offset, const void *val, size_t val_count)
 350{
 351	u32 addr_offset = cdev->mcfg[MRAM_TXB].off + fpi * TXB_ELEMENT_SIZE +
 352		offset;
 353
 354	if (val_count == 0)
 355		return 0;
 356
 357	return cdev->ops->write_fifo(cdev, addr_offset, val, val_count);
 358}
 359
 360static inline int m_can_fifo_write_no_off(struct m_can_classdev *cdev,
 361					  u32 fpi, u32 val)
 362{
 363	return cdev->ops->write_fifo(cdev, fpi, &val, 1);
 364}
 365
 366static int
 367m_can_txe_fifo_read(struct m_can_classdev *cdev, u32 fgi, u32 offset, u32 *val)
 368{
 369	u32 addr_offset = cdev->mcfg[MRAM_TXE].off + fgi * TXE_ELEMENT_SIZE +
 370		offset;
 371
 372	return cdev->ops->read_fifo(cdev, addr_offset, val, 1);
 373}
 374
 375static inline bool _m_can_tx_fifo_full(u32 txfqs)
 376{
 377	return !!(txfqs & TXFQS_TFQF);
 378}
 379
 380static inline bool m_can_tx_fifo_full(struct m_can_classdev *cdev)
 381{
 382	return _m_can_tx_fifo_full(m_can_read(cdev, M_CAN_TXFQS));
 383}
 384
 385static void m_can_config_endisable(struct m_can_classdev *cdev, bool enable)
 386{
 387	u32 cccr = m_can_read(cdev, M_CAN_CCCR);
 388	u32 timeout = 10;
 389	u32 val = 0;
 390
 391	/* Clear the Clock stop request if it was set */
 392	if (cccr & CCCR_CSR)
 393		cccr &= ~CCCR_CSR;
 394
 395	if (enable) {
 396		/* enable m_can configuration */
 397		m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT);
 398		udelay(5);
 399		/* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */
 400		m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
 401	} else {
 402		m_can_write(cdev, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE));
 403	}
 404
 405	/* there's a delay for module initialization */
 406	if (enable)
 407		val = CCCR_INIT | CCCR_CCE;
 408
 409	while ((m_can_read(cdev, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
 410		if (timeout == 0) {
 411			netdev_warn(cdev->net, "Failed to init module\n");
 412			return;
 413		}
 414		timeout--;
 415		udelay(1);
 416	}
 417}
 418
 419static inline void m_can_enable_all_interrupts(struct m_can_classdev *cdev)
 420{
 421	/* Only interrupt line 0 is used in this driver */
 422	m_can_write(cdev, M_CAN_ILE, ILE_EINT0);
 423}
 424
 425static inline void m_can_disable_all_interrupts(struct m_can_classdev *cdev)
 426{
 427	m_can_write(cdev, M_CAN_ILE, 0x0);
 428}
 429
 430/* Retrieve internal timestamp counter from TSCV.TSC, and shift it to 32-bit
 431 * width.
 432 */
 433static u32 m_can_get_timestamp(struct m_can_classdev *cdev)
 434{
 435	u32 tscv;
 436	u32 tsc;
 437
 438	tscv = m_can_read(cdev, M_CAN_TSCV);
 439	tsc = FIELD_GET(TSCV_TSC_MASK, tscv);
 440
 441	return (tsc << 16);
 442}
 443
 444static void m_can_clean(struct net_device *net)
 445{
 446	struct m_can_classdev *cdev = netdev_priv(net);
 447
 448	if (cdev->tx_skb) {
 449		int putidx = 0;
 450
 451		net->stats.tx_errors++;
 452		if (cdev->version > 30)
 453			putidx = FIELD_GET(TXFQS_TFQPI_MASK,
 454					   m_can_read(cdev, M_CAN_TXFQS));
 455
 456		can_free_echo_skb(cdev->net, putidx, NULL);
 457		cdev->tx_skb = NULL;
 458	}
 459}
 460
 461/* For peripherals, pass skb to rx-offload, which will push skb from
 462 * napi. For non-peripherals, RX is done in napi already, so push
 463 * directly. timestamp is used to ensure good skb ordering in
 464 * rx-offload and is ignored for non-peripherals.
 465 */
 466static void m_can_receive_skb(struct m_can_classdev *cdev,
 467			      struct sk_buff *skb,
 468			      u32 timestamp)
 469{
 470	if (cdev->is_peripheral) {
 471		struct net_device_stats *stats = &cdev->net->stats;
 472		int err;
 473
 474		err = can_rx_offload_queue_timestamp(&cdev->offload, skb,
 475						     timestamp);
 476		if (err)
 477			stats->rx_fifo_errors++;
 478	} else {
 479		netif_receive_skb(skb);
 480	}
 481}
 482
 483static int m_can_read_fifo(struct net_device *dev, u32 fgi)
 484{
 485	struct net_device_stats *stats = &dev->stats;
 486	struct m_can_classdev *cdev = netdev_priv(dev);
 487	struct canfd_frame *cf;
 488	struct sk_buff *skb;
 489	struct id_and_dlc fifo_header;
 490	u32 timestamp = 0;
 491	int err;
 492
 493	err = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_ID, &fifo_header, 2);
 494	if (err)
 495		goto out_fail;
 496
 497	if (fifo_header.dlc & RX_BUF_FDF)
 498		skb = alloc_canfd_skb(dev, &cf);
 499	else
 500		skb = alloc_can_skb(dev, (struct can_frame **)&cf);
 501	if (!skb) {
 502		stats->rx_dropped++;
 503		return 0;
 504	}
 505
 506	if (fifo_header.dlc & RX_BUF_FDF)
 507		cf->len = can_fd_dlc2len((fifo_header.dlc >> 16) & 0x0F);
 508	else
 509		cf->len = can_cc_dlc2len((fifo_header.dlc >> 16) & 0x0F);
 510
 511	if (fifo_header.id & RX_BUF_XTD)
 512		cf->can_id = (fifo_header.id & CAN_EFF_MASK) | CAN_EFF_FLAG;
 513	else
 514		cf->can_id = (fifo_header.id >> 18) & CAN_SFF_MASK;
 515
 516	if (fifo_header.id & RX_BUF_ESI) {
 517		cf->flags |= CANFD_ESI;
 518		netdev_dbg(dev, "ESI Error\n");
 519	}
 520
 521	if (!(fifo_header.dlc & RX_BUF_FDF) && (fifo_header.id & RX_BUF_RTR)) {
 522		cf->can_id |= CAN_RTR_FLAG;
 523	} else {
 524		if (fifo_header.dlc & RX_BUF_BRS)
 525			cf->flags |= CANFD_BRS;
 526
 527		err = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_DATA,
 528				      cf->data, DIV_ROUND_UP(cf->len, 4));
 529		if (err)
 530			goto out_free_skb;
 531
 532		stats->rx_bytes += cf->len;
 533	}
 534	stats->rx_packets++;
 535
 536	timestamp = FIELD_GET(RX_BUF_RXTS_MASK, fifo_header.dlc) << 16;
 537
 538	m_can_receive_skb(cdev, skb, timestamp);
 539
 540	return 0;
 541
 542out_free_skb:
 543	kfree_skb(skb);
 544out_fail:
 545	netdev_err(dev, "FIFO read returned %d\n", err);
 546	return err;
 547}
 548
 549static int m_can_do_rx_poll(struct net_device *dev, int quota)
 550{
 551	struct m_can_classdev *cdev = netdev_priv(dev);
 552	u32 pkts = 0;
 553	u32 rxfs;
 554	u32 rx_count;
 555	u32 fgi;
 556	int ack_fgi = -1;
 557	int i;
 558	int err = 0;
 559
 560	rxfs = m_can_read(cdev, M_CAN_RXF0S);
 561	if (!(rxfs & RXFS_FFL_MASK)) {
 562		netdev_dbg(dev, "no messages in fifo0\n");
 563		return 0;
 564	}
 565
 566	rx_count = FIELD_GET(RXFS_FFL_MASK, rxfs);
 567	fgi = FIELD_GET(RXFS_FGI_MASK, rxfs);
 568
 569	for (i = 0; i < rx_count && quota > 0; ++i) {
 570		err = m_can_read_fifo(dev, fgi);
 571		if (err)
 572			break;
 573
 574		quota--;
 575		pkts++;
 576		ack_fgi = fgi;
 577		fgi = (++fgi >= cdev->mcfg[MRAM_RXF0].num ? 0 : fgi);
 578	}
 579
 580	if (ack_fgi != -1)
 581		m_can_write(cdev, M_CAN_RXF0A, ack_fgi);
 582
 583	if (err)
 584		return err;
 585
 586	return pkts;
 587}
 588
 589static int m_can_handle_lost_msg(struct net_device *dev)
 590{
 591	struct m_can_classdev *cdev = netdev_priv(dev);
 592	struct net_device_stats *stats = &dev->stats;
 593	struct sk_buff *skb;
 594	struct can_frame *frame;
 595	u32 timestamp = 0;
 596
 597	netdev_err(dev, "msg lost in rxf0\n");
 598
 599	stats->rx_errors++;
 600	stats->rx_over_errors++;
 601
 602	skb = alloc_can_err_skb(dev, &frame);
 603	if (unlikely(!skb))
 604		return 0;
 605
 606	frame->can_id |= CAN_ERR_CRTL;
 607	frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 608
 609	if (cdev->is_peripheral)
 610		timestamp = m_can_get_timestamp(cdev);
 611
 612	m_can_receive_skb(cdev, skb, timestamp);
 613
 614	return 1;
 615}
 616
 617static int m_can_handle_lec_err(struct net_device *dev,
 618				enum m_can_lec_type lec_type)
 619{
 620	struct m_can_classdev *cdev = netdev_priv(dev);
 621	struct net_device_stats *stats = &dev->stats;
 622	struct can_frame *cf;
 623	struct sk_buff *skb;
 624	u32 timestamp = 0;
 625
 626	cdev->can.can_stats.bus_error++;
 627	stats->rx_errors++;
 628
 629	/* propagate the error condition to the CAN stack */
 630	skb = alloc_can_err_skb(dev, &cf);
 631	if (unlikely(!skb))
 632		return 0;
 633
 634	/* check for 'last error code' which tells us the
 635	 * type of the last error to occur on the CAN bus
 636	 */
 637	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 638
 639	switch (lec_type) {
 640	case LEC_STUFF_ERROR:
 641		netdev_dbg(dev, "stuff error\n");
 642		cf->data[2] |= CAN_ERR_PROT_STUFF;
 643		break;
 644	case LEC_FORM_ERROR:
 645		netdev_dbg(dev, "form error\n");
 646		cf->data[2] |= CAN_ERR_PROT_FORM;
 647		break;
 648	case LEC_ACK_ERROR:
 649		netdev_dbg(dev, "ack error\n");
 650		cf->data[3] = CAN_ERR_PROT_LOC_ACK;
 651		break;
 652	case LEC_BIT1_ERROR:
 653		netdev_dbg(dev, "bit1 error\n");
 654		cf->data[2] |= CAN_ERR_PROT_BIT1;
 655		break;
 656	case LEC_BIT0_ERROR:
 657		netdev_dbg(dev, "bit0 error\n");
 658		cf->data[2] |= CAN_ERR_PROT_BIT0;
 659		break;
 660	case LEC_CRC_ERROR:
 661		netdev_dbg(dev, "CRC error\n");
 662		cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 663		break;
 664	default:
 665		break;
 666	}
 667
 668	if (cdev->is_peripheral)
 669		timestamp = m_can_get_timestamp(cdev);
 670
 671	m_can_receive_skb(cdev, skb, timestamp);
 672
 673	return 1;
 674}
 675
 676static int __m_can_get_berr_counter(const struct net_device *dev,
 677				    struct can_berr_counter *bec)
 678{
 679	struct m_can_classdev *cdev = netdev_priv(dev);
 680	unsigned int ecr;
 681
 682	ecr = m_can_read(cdev, M_CAN_ECR);
 683	bec->rxerr = FIELD_GET(ECR_REC_MASK, ecr);
 684	bec->txerr = FIELD_GET(ECR_TEC_MASK, ecr);
 685
 686	return 0;
 687}
 688
 689static int m_can_clk_start(struct m_can_classdev *cdev)
 690{
 691	if (cdev->pm_clock_support == 0)
 692		return 0;
 693
 694	return pm_runtime_resume_and_get(cdev->dev);
 695}
 696
 697static void m_can_clk_stop(struct m_can_classdev *cdev)
 698{
 699	if (cdev->pm_clock_support)
 700		pm_runtime_put_sync(cdev->dev);
 701}
 702
 703static int m_can_get_berr_counter(const struct net_device *dev,
 704				  struct can_berr_counter *bec)
 705{
 706	struct m_can_classdev *cdev = netdev_priv(dev);
 707	int err;
 708
 709	err = m_can_clk_start(cdev);
 710	if (err)
 711		return err;
 712
 713	__m_can_get_berr_counter(dev, bec);
 714
 715	m_can_clk_stop(cdev);
 716
 717	return 0;
 718}
 719
 720static int m_can_handle_state_change(struct net_device *dev,
 721				     enum can_state new_state)
 722{
 723	struct m_can_classdev *cdev = netdev_priv(dev);
 724	struct can_frame *cf;
 725	struct sk_buff *skb;
 726	struct can_berr_counter bec;
 727	unsigned int ecr;
 728	u32 timestamp = 0;
 729
 730	switch (new_state) {
 731	case CAN_STATE_ERROR_WARNING:
 732		/* error warning state */
 733		cdev->can.can_stats.error_warning++;
 734		cdev->can.state = CAN_STATE_ERROR_WARNING;
 735		break;
 736	case CAN_STATE_ERROR_PASSIVE:
 737		/* error passive state */
 738		cdev->can.can_stats.error_passive++;
 739		cdev->can.state = CAN_STATE_ERROR_PASSIVE;
 740		break;
 741	case CAN_STATE_BUS_OFF:
 742		/* bus-off state */
 743		cdev->can.state = CAN_STATE_BUS_OFF;
 744		m_can_disable_all_interrupts(cdev);
 745		cdev->can.can_stats.bus_off++;
 746		can_bus_off(dev);
 747		break;
 748	default:
 749		break;
 750	}
 751
 752	/* propagate the error condition to the CAN stack */
 753	skb = alloc_can_err_skb(dev, &cf);
 754	if (unlikely(!skb))
 755		return 0;
 756
 757	__m_can_get_berr_counter(dev, &bec);
 758
 759	switch (new_state) {
 760	case CAN_STATE_ERROR_WARNING:
 761		/* error warning state */
 762		cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;
 763		cf->data[1] = (bec.txerr > bec.rxerr) ?
 764			CAN_ERR_CRTL_TX_WARNING :
 765			CAN_ERR_CRTL_RX_WARNING;
 766		cf->data[6] = bec.txerr;
 767		cf->data[7] = bec.rxerr;
 768		break;
 769	case CAN_STATE_ERROR_PASSIVE:
 770		/* error passive state */
 771		cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;
 772		ecr = m_can_read(cdev, M_CAN_ECR);
 773		if (ecr & ECR_RP)
 774			cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
 775		if (bec.txerr > 127)
 776			cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
 777		cf->data[6] = bec.txerr;
 778		cf->data[7] = bec.rxerr;
 779		break;
 780	case CAN_STATE_BUS_OFF:
 781		/* bus-off state */
 782		cf->can_id |= CAN_ERR_BUSOFF;
 783		break;
 784	default:
 785		break;
 786	}
 787
 788	if (cdev->is_peripheral)
 789		timestamp = m_can_get_timestamp(cdev);
 790
 791	m_can_receive_skb(cdev, skb, timestamp);
 792
 793	return 1;
 794}
 795
 796static int m_can_handle_state_errors(struct net_device *dev, u32 psr)
 797{
 798	struct m_can_classdev *cdev = netdev_priv(dev);
 799	int work_done = 0;
 800
 801	if (psr & PSR_EW && cdev->can.state != CAN_STATE_ERROR_WARNING) {
 802		netdev_dbg(dev, "entered error warning state\n");
 803		work_done += m_can_handle_state_change(dev,
 804						       CAN_STATE_ERROR_WARNING);
 805	}
 806
 807	if (psr & PSR_EP && cdev->can.state != CAN_STATE_ERROR_PASSIVE) {
 808		netdev_dbg(dev, "entered error passive state\n");
 809		work_done += m_can_handle_state_change(dev,
 810						       CAN_STATE_ERROR_PASSIVE);
 811	}
 812
 813	if (psr & PSR_BO && cdev->can.state != CAN_STATE_BUS_OFF) {
 814		netdev_dbg(dev, "entered error bus off state\n");
 815		work_done += m_can_handle_state_change(dev,
 816						       CAN_STATE_BUS_OFF);
 817	}
 818
 819	return work_done;
 820}
 821
 822static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus)
 823{
 824	if (irqstatus & IR_WDI)
 825		netdev_err(dev, "Message RAM Watchdog event due to missing READY\n");
 826	if (irqstatus & IR_BEU)
 827		netdev_err(dev, "Bit Error Uncorrected\n");
 828	if (irqstatus & IR_BEC)
 829		netdev_err(dev, "Bit Error Corrected\n");
 830	if (irqstatus & IR_TOO)
 831		netdev_err(dev, "Timeout reached\n");
 832	if (irqstatus & IR_MRAF)
 833		netdev_err(dev, "Message RAM access failure occurred\n");
 834}
 835
 836static inline bool is_lec_err(u8 lec)
 837{
 838	return lec != LEC_NO_ERROR && lec != LEC_NO_CHANGE;
 839}
 840
 841static inline bool m_can_is_protocol_err(u32 irqstatus)
 842{
 843	return irqstatus & IR_ERR_LEC_31X;
 844}
 845
 846static int m_can_handle_protocol_error(struct net_device *dev, u32 irqstatus)
 847{
 848	struct net_device_stats *stats = &dev->stats;
 849	struct m_can_classdev *cdev = netdev_priv(dev);
 850	struct can_frame *cf;
 851	struct sk_buff *skb;
 852	u32 timestamp = 0;
 853
 854	/* propagate the error condition to the CAN stack */
 855	skb = alloc_can_err_skb(dev, &cf);
 856
 857	/* update tx error stats since there is protocol error */
 858	stats->tx_errors++;
 859
 860	/* update arbitration lost status */
 861	if (cdev->version >= 31 && (irqstatus & IR_PEA)) {
 862		netdev_dbg(dev, "Protocol error in Arbitration fail\n");
 863		cdev->can.can_stats.arbitration_lost++;
 864		if (skb) {
 865			cf->can_id |= CAN_ERR_LOSTARB;
 866			cf->data[0] |= CAN_ERR_LOSTARB_UNSPEC;
 867		}
 868	}
 869
 870	if (unlikely(!skb)) {
 871		netdev_dbg(dev, "allocation of skb failed\n");
 872		return 0;
 873	}
 874
 875	if (cdev->is_peripheral)
 876		timestamp = m_can_get_timestamp(cdev);
 877
 878	m_can_receive_skb(cdev, skb, timestamp);
 879
 880	return 1;
 881}
 882
 883static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
 884				   u32 psr)
 885{
 886	struct m_can_classdev *cdev = netdev_priv(dev);
 887	int work_done = 0;
 888
 889	if (irqstatus & IR_RF0L)
 890		work_done += m_can_handle_lost_msg(dev);
 891
 892	/* handle lec errors on the bus */
 893	if (cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
 894		u8 lec = FIELD_GET(PSR_LEC_MASK, psr);
 895		u8 dlec = FIELD_GET(PSR_DLEC_MASK, psr);
 896
 897		if (is_lec_err(lec)) {
 898			netdev_dbg(dev, "Arbitration phase error detected\n");
 899			work_done += m_can_handle_lec_err(dev, lec);
 900		}
 901
 902		if (is_lec_err(dlec)) {
 903			netdev_dbg(dev, "Data phase error detected\n");
 904			work_done += m_can_handle_lec_err(dev, dlec);
 905		}
 906	}
 907
 908	/* handle protocol errors in arbitration phase */
 909	if ((cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
 910	    m_can_is_protocol_err(irqstatus))
 911		work_done += m_can_handle_protocol_error(dev, irqstatus);
 912
 913	/* other unproccessed error interrupts */
 914	m_can_handle_other_err(dev, irqstatus);
 915
 916	return work_done;
 917}
 918
 919static int m_can_rx_handler(struct net_device *dev, int quota, u32 irqstatus)
 920{
 921	struct m_can_classdev *cdev = netdev_priv(dev);
 922	int rx_work_or_err;
 923	int work_done = 0;
 924
 925	if (!irqstatus)
 926		goto end;
 927
 928	/* Errata workaround for issue "Needless activation of MRAF irq"
 929	 * During frame reception while the MCAN is in Error Passive state
 930	 * and the Receive Error Counter has the value MCAN_ECR.REC = 127,
 931	 * it may happen that MCAN_IR.MRAF is set although there was no
 932	 * Message RAM access failure.
 933	 * If MCAN_IR.MRAF is enabled, an interrupt to the Host CPU is generated
 934	 * The Message RAM Access Failure interrupt routine needs to check
 935	 * whether MCAN_ECR.RP = ’1’ and MCAN_ECR.REC = 127.
 936	 * In this case, reset MCAN_IR.MRAF. No further action is required.
 937	 */
 938	if (cdev->version <= 31 && irqstatus & IR_MRAF &&
 939	    m_can_read(cdev, M_CAN_ECR) & ECR_RP) {
 940		struct can_berr_counter bec;
 941
 942		__m_can_get_berr_counter(dev, &bec);
 943		if (bec.rxerr == 127) {
 944			m_can_write(cdev, M_CAN_IR, IR_MRAF);
 945			irqstatus &= ~IR_MRAF;
 946		}
 947	}
 948
 949	if (irqstatus & IR_ERR_STATE)
 950		work_done += m_can_handle_state_errors(dev,
 951						       m_can_read(cdev, M_CAN_PSR));
 952
 953	if (irqstatus & IR_ERR_BUS_30X)
 954		work_done += m_can_handle_bus_errors(dev, irqstatus,
 955						     m_can_read(cdev, M_CAN_PSR));
 956
 957	if (irqstatus & IR_RF0N) {
 958		rx_work_or_err = m_can_do_rx_poll(dev, (quota - work_done));
 959		if (rx_work_or_err < 0)
 960			return rx_work_or_err;
 961
 962		work_done += rx_work_or_err;
 963	}
 964end:
 965	return work_done;
 966}
 967
 968static int m_can_rx_peripheral(struct net_device *dev, u32 irqstatus)
 969{
 970	struct m_can_classdev *cdev = netdev_priv(dev);
 971	int work_done;
 972
 973	work_done = m_can_rx_handler(dev, NAPI_POLL_WEIGHT, irqstatus);
 974
 975	/* Don't re-enable interrupts if the driver had a fatal error
 976	 * (e.g., FIFO read failure).
 977	 */
 978	if (work_done < 0)
 979		m_can_disable_all_interrupts(cdev);
 980
 981	return work_done;
 982}
 983
 984static int m_can_poll(struct napi_struct *napi, int quota)
 985{
 986	struct net_device *dev = napi->dev;
 987	struct m_can_classdev *cdev = netdev_priv(dev);
 988	int work_done;
 989	u32 irqstatus;
 990
 991	irqstatus = cdev->irqstatus | m_can_read(cdev, M_CAN_IR);
 992
 993	work_done = m_can_rx_handler(dev, quota, irqstatus);
 994
 995	/* Don't re-enable interrupts if the driver had a fatal error
 996	 * (e.g., FIFO read failure).
 997	 */
 998	if (work_done >= 0 && work_done < quota) {
 999		napi_complete_done(napi, work_done);
1000		m_can_enable_all_interrupts(cdev);
1001	}
1002
1003	return work_done;
1004}
1005
1006/* Echo tx skb and update net stats. Peripherals use rx-offload for
1007 * echo. timestamp is used for peripherals to ensure correct ordering
1008 * by rx-offload, and is ignored for non-peripherals.
1009 */
1010static void m_can_tx_update_stats(struct m_can_classdev *cdev,
1011				  unsigned int msg_mark,
1012				  u32 timestamp)
1013{
1014	struct net_device *dev = cdev->net;
1015	struct net_device_stats *stats = &dev->stats;
1016
1017	if (cdev->is_peripheral)
1018		stats->tx_bytes +=
1019			can_rx_offload_get_echo_skb_queue_timestamp(&cdev->offload,
1020								    msg_mark,
1021								    timestamp,
1022								    NULL);
1023	else
1024		stats->tx_bytes += can_get_echo_skb(dev, msg_mark, NULL);
1025
1026	stats->tx_packets++;
1027}
1028
1029static int m_can_echo_tx_event(struct net_device *dev)
1030{
1031	u32 txe_count = 0;
1032	u32 m_can_txefs;
1033	u32 fgi = 0;
1034	int ack_fgi = -1;
1035	int i = 0;
1036	int err = 0;
1037	unsigned int msg_mark;
1038
1039	struct m_can_classdev *cdev = netdev_priv(dev);
1040
1041	/* read tx event fifo status */
1042	m_can_txefs = m_can_read(cdev, M_CAN_TXEFS);
1043
1044	/* Get Tx Event fifo element count */
1045	txe_count = FIELD_GET(TXEFS_EFFL_MASK, m_can_txefs);
1046	fgi = FIELD_GET(TXEFS_EFGI_MASK, m_can_txefs);
1047
1048	/* Get and process all sent elements */
1049	for (i = 0; i < txe_count; i++) {
1050		u32 txe, timestamp = 0;
1051
1052		/* get message marker, timestamp */
1053		err = m_can_txe_fifo_read(cdev, fgi, 4, &txe);
1054		if (err) {
1055			netdev_err(dev, "TXE FIFO read returned %d\n", err);
1056			break;
1057		}
1058
1059		msg_mark = FIELD_GET(TX_EVENT_MM_MASK, txe);
1060		timestamp = FIELD_GET(TX_EVENT_TXTS_MASK, txe) << 16;
1061
1062		ack_fgi = fgi;
1063		fgi = (++fgi >= cdev->mcfg[MRAM_TXE].num ? 0 : fgi);
1064
1065		/* update stats */
1066		m_can_tx_update_stats(cdev, msg_mark, timestamp);
1067	}
1068
1069	if (ack_fgi != -1)
1070		m_can_write(cdev, M_CAN_TXEFA, FIELD_PREP(TXEFA_EFAI_MASK,
1071							  ack_fgi));
1072
1073	return err;
1074}
1075
1076static irqreturn_t m_can_isr(int irq, void *dev_id)
1077{
1078	struct net_device *dev = (struct net_device *)dev_id;
1079	struct m_can_classdev *cdev = netdev_priv(dev);
1080	u32 ir;
1081
1082	if (pm_runtime_suspended(cdev->dev))
1083		return IRQ_NONE;
1084	ir = m_can_read(cdev, M_CAN_IR);
1085	if (!ir)
1086		return IRQ_NONE;
1087
1088	/* ACK all irqs */
1089	m_can_write(cdev, M_CAN_IR, ir);
1090
1091	if (cdev->ops->clear_interrupts)
1092		cdev->ops->clear_interrupts(cdev);
1093
1094	/* schedule NAPI in case of
1095	 * - rx IRQ
1096	 * - state change IRQ
1097	 * - bus error IRQ and bus error reporting
1098	 */
1099	if ((ir & IR_RF0N) || (ir & IR_ERR_ALL_30X)) {
1100		cdev->irqstatus = ir;
1101		if (!cdev->is_peripheral) {
1102			m_can_disable_all_interrupts(cdev);
1103			napi_schedule(&cdev->napi);
1104		} else if (m_can_rx_peripheral(dev, ir) < 0) {
1105			goto out_fail;
1106		}
1107	}
1108
1109	if (cdev->version == 30) {
1110		if (ir & IR_TC) {
1111			/* Transmission Complete Interrupt*/
1112			u32 timestamp = 0;
1113
1114			if (cdev->is_peripheral)
1115				timestamp = m_can_get_timestamp(cdev);
1116			m_can_tx_update_stats(cdev, 0, timestamp);
1117			netif_wake_queue(dev);
1118		}
1119	} else  {
1120		if (ir & IR_TEFN) {
1121			/* New TX FIFO Element arrived */
1122			if (m_can_echo_tx_event(dev) != 0)
1123				goto out_fail;
1124
1125			if (netif_queue_stopped(dev) &&
1126			    !m_can_tx_fifo_full(cdev))
1127				netif_wake_queue(dev);
1128		}
1129	}
1130
1131	if (cdev->is_peripheral)
1132		can_rx_offload_threaded_irq_finish(&cdev->offload);
1133
1134	return IRQ_HANDLED;
1135
1136out_fail:
1137	m_can_disable_all_interrupts(cdev);
1138	return IRQ_HANDLED;
1139}
1140
1141static const struct can_bittiming_const m_can_bittiming_const_30X = {
1142	.name = KBUILD_MODNAME,
1143	.tseg1_min = 2,		/* Time segment 1 = prop_seg + phase_seg1 */
1144	.tseg1_max = 64,
1145	.tseg2_min = 1,		/* Time segment 2 = phase_seg2 */
1146	.tseg2_max = 16,
1147	.sjw_max = 16,
1148	.brp_min = 1,
1149	.brp_max = 1024,
1150	.brp_inc = 1,
1151};
1152
1153static const struct can_bittiming_const m_can_data_bittiming_const_30X = {
1154	.name = KBUILD_MODNAME,
1155	.tseg1_min = 2,		/* Time segment 1 = prop_seg + phase_seg1 */
1156	.tseg1_max = 16,
1157	.tseg2_min = 1,		/* Time segment 2 = phase_seg2 */
1158	.tseg2_max = 8,
1159	.sjw_max = 4,
1160	.brp_min = 1,
1161	.brp_max = 32,
1162	.brp_inc = 1,
1163};
1164
1165static const struct can_bittiming_const m_can_bittiming_const_31X = {
1166	.name = KBUILD_MODNAME,
1167	.tseg1_min = 2,		/* Time segment 1 = prop_seg + phase_seg1 */
1168	.tseg1_max = 256,
1169	.tseg2_min = 2,		/* Time segment 2 = phase_seg2 */
1170	.tseg2_max = 128,
1171	.sjw_max = 128,
1172	.brp_min = 1,
1173	.brp_max = 512,
1174	.brp_inc = 1,
1175};
1176
1177static const struct can_bittiming_const m_can_data_bittiming_const_31X = {
1178	.name = KBUILD_MODNAME,
1179	.tseg1_min = 1,		/* Time segment 1 = prop_seg + phase_seg1 */
1180	.tseg1_max = 32,
1181	.tseg2_min = 1,		/* Time segment 2 = phase_seg2 */
1182	.tseg2_max = 16,
1183	.sjw_max = 16,
1184	.brp_min = 1,
1185	.brp_max = 32,
1186	.brp_inc = 1,
1187};
1188
1189static int m_can_set_bittiming(struct net_device *dev)
1190{
1191	struct m_can_classdev *cdev = netdev_priv(dev);
1192	const struct can_bittiming *bt = &cdev->can.bittiming;
1193	const struct can_bittiming *dbt = &cdev->can.data_bittiming;
1194	u16 brp, sjw, tseg1, tseg2;
1195	u32 reg_btp;
1196
1197	brp = bt->brp - 1;
1198	sjw = bt->sjw - 1;
1199	tseg1 = bt->prop_seg + bt->phase_seg1 - 1;
1200	tseg2 = bt->phase_seg2 - 1;
1201	reg_btp = FIELD_PREP(NBTP_NBRP_MASK, brp) |
1202		  FIELD_PREP(NBTP_NSJW_MASK, sjw) |
1203		  FIELD_PREP(NBTP_NTSEG1_MASK, tseg1) |
1204		  FIELD_PREP(NBTP_NTSEG2_MASK, tseg2);
1205	m_can_write(cdev, M_CAN_NBTP, reg_btp);
1206
1207	if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
1208		reg_btp = 0;
1209		brp = dbt->brp - 1;
1210		sjw = dbt->sjw - 1;
1211		tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
1212		tseg2 = dbt->phase_seg2 - 1;
1213
1214		/* TDC is only needed for bitrates beyond 2.5 MBit/s.
1215		 * This is mentioned in the "Bit Time Requirements for CAN FD"
1216		 * paper presented at the International CAN Conference 2013
1217		 */
1218		if (dbt->bitrate > 2500000) {
1219			u32 tdco, ssp;
1220
1221			/* Use the same value of secondary sampling point
1222			 * as the data sampling point
1223			 */
1224			ssp = dbt->sample_point;
1225
1226			/* Equation based on Bosch's M_CAN User Manual's
1227			 * Transmitter Delay Compensation Section
1228			 */
1229			tdco = (cdev->can.clock.freq / 1000) *
1230				ssp / dbt->bitrate;
1231
1232			/* Max valid TDCO value is 127 */
1233			if (tdco > 127) {
1234				netdev_warn(dev, "TDCO value of %u is beyond maximum. Using maximum possible value\n",
1235					    tdco);
1236				tdco = 127;
1237			}
1238
1239			reg_btp |= DBTP_TDC;
1240			m_can_write(cdev, M_CAN_TDCR,
1241				    FIELD_PREP(TDCR_TDCO_MASK, tdco));
1242		}
1243
1244		reg_btp |= FIELD_PREP(DBTP_DBRP_MASK, brp) |
1245			FIELD_PREP(DBTP_DSJW_MASK, sjw) |
1246			FIELD_PREP(DBTP_DTSEG1_MASK, tseg1) |
1247			FIELD_PREP(DBTP_DTSEG2_MASK, tseg2);
1248
1249		m_can_write(cdev, M_CAN_DBTP, reg_btp);
1250	}
1251
1252	return 0;
1253}
1254
1255/* Configure M_CAN chip:
1256 * - set rx buffer/fifo element size
1257 * - configure rx fifo
1258 * - accept non-matching frame into fifo 0
1259 * - configure tx buffer
1260 *		- >= v3.1.x: TX FIFO is used
1261 * - configure mode
1262 * - setup bittiming
1263 * - configure timestamp generation
1264 */
1265static int m_can_chip_config(struct net_device *dev)
1266{
1267	struct m_can_classdev *cdev = netdev_priv(dev);
1268	u32 interrupts = IR_ALL_INT;
1269	u32 cccr, test;
1270	int err;
1271
1272	err = m_can_init_ram(cdev);
1273	if (err) {
1274		dev_err(cdev->dev, "Message RAM configuration failed\n");
1275		return err;
1276	}
1277
1278	/* Disable unused interrupts */
1279	interrupts &= ~(IR_ARA | IR_ELO | IR_DRX | IR_TEFF | IR_TEFW | IR_TFE |
1280			IR_TCF | IR_HPM | IR_RF1F | IR_RF1W | IR_RF1N |
1281			IR_RF0F | IR_RF0W);
1282
1283	m_can_config_endisable(cdev, true);
1284
1285	/* RX Buffer/FIFO Element Size 64 bytes data field */
1286	m_can_write(cdev, M_CAN_RXESC,
1287		    FIELD_PREP(RXESC_RBDS_MASK, RXESC_64B) |
1288		    FIELD_PREP(RXESC_F1DS_MASK, RXESC_64B) |
1289		    FIELD_PREP(RXESC_F0DS_MASK, RXESC_64B));
1290
1291	/* Accept Non-matching Frames Into FIFO 0 */
1292	m_can_write(cdev, M_CAN_GFC, 0x0);
1293
1294	if (cdev->version == 30) {
1295		/* only support one Tx Buffer currently */
1296		m_can_write(cdev, M_CAN_TXBC, FIELD_PREP(TXBC_NDTB_MASK, 1) |
1297			    cdev->mcfg[MRAM_TXB].off);
1298	} else {
1299		/* TX FIFO is used for newer IP Core versions */
1300		m_can_write(cdev, M_CAN_TXBC,
1301			    FIELD_PREP(TXBC_TFQS_MASK,
1302				       cdev->mcfg[MRAM_TXB].num) |
1303			    cdev->mcfg[MRAM_TXB].off);
1304	}
1305
1306	/* support 64 bytes payload */
1307	m_can_write(cdev, M_CAN_TXESC,
1308		    FIELD_PREP(TXESC_TBDS_MASK, TXESC_TBDS_64B));
1309
1310	/* TX Event FIFO */
1311	if (cdev->version == 30) {
1312		m_can_write(cdev, M_CAN_TXEFC,
1313			    FIELD_PREP(TXEFC_EFS_MASK, 1) |
1314			    cdev->mcfg[MRAM_TXE].off);
1315	} else {
1316		/* Full TX Event FIFO is used */
1317		m_can_write(cdev, M_CAN_TXEFC,
1318			    FIELD_PREP(TXEFC_EFS_MASK,
1319				       cdev->mcfg[MRAM_TXE].num) |
1320			    cdev->mcfg[MRAM_TXE].off);
1321	}
1322
1323	/* rx fifo configuration, blocking mode, fifo size 1 */
1324	m_can_write(cdev, M_CAN_RXF0C,
1325		    FIELD_PREP(RXFC_FS_MASK, cdev->mcfg[MRAM_RXF0].num) |
1326		    cdev->mcfg[MRAM_RXF0].off);
1327
1328	m_can_write(cdev, M_CAN_RXF1C,
1329		    FIELD_PREP(RXFC_FS_MASK, cdev->mcfg[MRAM_RXF1].num) |
1330		    cdev->mcfg[MRAM_RXF1].off);
1331
1332	cccr = m_can_read(cdev, M_CAN_CCCR);
1333	test = m_can_read(cdev, M_CAN_TEST);
1334	test &= ~TEST_LBCK;
1335	if (cdev->version == 30) {
1336		/* Version 3.0.x */
1337
1338		cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_DAR |
1339			  FIELD_PREP(CCCR_CMR_MASK, FIELD_MAX(CCCR_CMR_MASK)) |
1340			  FIELD_PREP(CCCR_CME_MASK, FIELD_MAX(CCCR_CME_MASK)));
1341
1342		if (cdev->can.ctrlmode & CAN_CTRLMODE_FD)
1343			cccr |= FIELD_PREP(CCCR_CME_MASK, CCCR_CME_CANFD_BRS);
1344
1345	} else {
1346		/* Version 3.1.x or 3.2.x */
1347		cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_BRSE | CCCR_FDOE |
1348			  CCCR_NISO | CCCR_DAR);
1349
1350		/* Only 3.2.x has NISO Bit implemented */
1351		if (cdev->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
1352			cccr |= CCCR_NISO;
1353
1354		if (cdev->can.ctrlmode & CAN_CTRLMODE_FD)
1355			cccr |= (CCCR_BRSE | CCCR_FDOE);
1356	}
1357
1358	/* Loopback Mode */
1359	if (cdev->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
1360		cccr |= CCCR_TEST | CCCR_MON;
1361		test |= TEST_LBCK;
1362	}
1363
1364	/* Enable Monitoring (all versions) */
1365	if (cdev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
1366		cccr |= CCCR_MON;
1367
1368	/* Disable Auto Retransmission (all versions) */
1369	if (cdev->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
1370		cccr |= CCCR_DAR;
1371
1372	/* Write config */
1373	m_can_write(cdev, M_CAN_CCCR, cccr);
1374	m_can_write(cdev, M_CAN_TEST, test);
1375
1376	/* Enable interrupts */
1377	if (!(cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
1378		if (cdev->version == 30)
1379			interrupts &= ~(IR_ERR_LEC_30X);
1380		else
1381			interrupts &= ~(IR_ERR_LEC_31X);
1382	}
1383	m_can_write(cdev, M_CAN_IE, interrupts);
1384
1385	/* route all interrupts to INT0 */
1386	m_can_write(cdev, M_CAN_ILS, ILS_ALL_INT0);
1387
1388	/* set bittiming params */
1389	m_can_set_bittiming(dev);
1390
1391	/* enable internal timestamp generation, with a prescaler of 16. The
1392	 * prescaler is applied to the nominal bit timing
1393	 */
1394	m_can_write(cdev, M_CAN_TSCC,
1395		    FIELD_PREP(TSCC_TCP_MASK, 0xf) |
1396		    FIELD_PREP(TSCC_TSS_MASK, TSCC_TSS_INTERNAL));
1397
1398	m_can_config_endisable(cdev, false);
1399
1400	if (cdev->ops->init)
1401		cdev->ops->init(cdev);
1402
1403	return 0;
1404}
1405
1406static int m_can_start(struct net_device *dev)
1407{
1408	struct m_can_classdev *cdev = netdev_priv(dev);
1409	int ret;
1410
1411	/* basic m_can configuration */
1412	ret = m_can_chip_config(dev);
1413	if (ret)
1414		return ret;
1415
1416	cdev->can.state = CAN_STATE_ERROR_ACTIVE;
1417
1418	m_can_enable_all_interrupts(cdev);
1419
1420	if (!dev->irq) {
1421		dev_dbg(cdev->dev, "Start hrtimer\n");
1422		hrtimer_start(&cdev->hrtimer, ms_to_ktime(HRTIMER_POLL_INTERVAL_MS),
1423			      HRTIMER_MODE_REL_PINNED);
1424	}
1425
1426	return 0;
1427}
1428
1429static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
1430{
1431	switch (mode) {
1432	case CAN_MODE_START:
1433		m_can_clean(dev);
1434		m_can_start(dev);
1435		netif_wake_queue(dev);
1436		break;
1437	default:
1438		return -EOPNOTSUPP;
1439	}
1440
1441	return 0;
1442}
1443
1444/* Checks core release number of M_CAN
1445 * returns 0 if an unsupported device is detected
1446 * else it returns the release and step coded as:
1447 * return value = 10 * <release> + 1 * <step>
1448 */
1449static int m_can_check_core_release(struct m_can_classdev *cdev)
1450{
1451	u32 crel_reg;
1452	u8 rel;
1453	u8 step;
1454	int res;
1455
1456	/* Read Core Release Version and split into version number
1457	 * Example: Version 3.2.1 => rel = 3; step = 2; substep = 1;
1458	 */
1459	crel_reg = m_can_read(cdev, M_CAN_CREL);
1460	rel = (u8)FIELD_GET(CREL_REL_MASK, crel_reg);
1461	step = (u8)FIELD_GET(CREL_STEP_MASK, crel_reg);
1462
1463	if (rel == 3) {
1464		/* M_CAN v3.x.y: create return value */
1465		res = 30 + step;
1466	} else {
1467		/* Unsupported M_CAN version */
1468		res = 0;
1469	}
1470
1471	return res;
1472}
1473
1474/* Selectable Non ISO support only in version 3.2.x
1475 * This function checks if the bit is writable.
1476 */
1477static bool m_can_niso_supported(struct m_can_classdev *cdev)
1478{
1479	u32 cccr_reg, cccr_poll = 0;
1480	int niso_timeout = -ETIMEDOUT;
1481	int i;
1482
1483	m_can_config_endisable(cdev, true);
1484	cccr_reg = m_can_read(cdev, M_CAN_CCCR);
1485	cccr_reg |= CCCR_NISO;
1486	m_can_write(cdev, M_CAN_CCCR, cccr_reg);
1487
1488	for (i = 0; i <= 10; i++) {
1489		cccr_poll = m_can_read(cdev, M_CAN_CCCR);
1490		if (cccr_poll == cccr_reg) {
1491			niso_timeout = 0;
1492			break;
1493		}
1494
1495		usleep_range(1, 5);
1496	}
1497
1498	/* Clear NISO */
1499	cccr_reg &= ~(CCCR_NISO);
1500	m_can_write(cdev, M_CAN_CCCR, cccr_reg);
1501
1502	m_can_config_endisable(cdev, false);
1503
1504	/* return false if time out (-ETIMEDOUT), else return true */
1505	return !niso_timeout;
1506}
1507
1508static int m_can_dev_setup(struct m_can_classdev *cdev)
1509{
1510	struct net_device *dev = cdev->net;
1511	int m_can_version, err;
1512
1513	m_can_version = m_can_check_core_release(cdev);
1514	/* return if unsupported version */
1515	if (!m_can_version) {
1516		dev_err(cdev->dev, "Unsupported version number: %2d",
1517			m_can_version);
1518		return -EINVAL;
1519	}
1520
1521	if (!cdev->is_peripheral)
1522		netif_napi_add(dev, &cdev->napi, m_can_poll);
1523
1524	/* Shared properties of all M_CAN versions */
1525	cdev->version = m_can_version;
1526	cdev->can.do_set_mode = m_can_set_mode;
1527	cdev->can.do_get_berr_counter = m_can_get_berr_counter;
1528
1529	/* Set M_CAN supported operations */
1530	cdev->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1531		CAN_CTRLMODE_LISTENONLY |
1532		CAN_CTRLMODE_BERR_REPORTING |
1533		CAN_CTRLMODE_FD |
1534		CAN_CTRLMODE_ONE_SHOT;
1535
1536	/* Set properties depending on M_CAN version */
1537	switch (cdev->version) {
1538	case 30:
1539		/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */
1540		err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
1541		if (err)
1542			return err;
1543		cdev->can.bittiming_const = &m_can_bittiming_const_30X;
1544		cdev->can.data_bittiming_const = &m_can_data_bittiming_const_30X;
1545		break;
1546	case 31:
1547		/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */
1548		err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
1549		if (err)
1550			return err;
1551		cdev->can.bittiming_const = &m_can_bittiming_const_31X;
1552		cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
1553		break;
1554	case 32:
1555	case 33:
1556		/* Support both MCAN version v3.2.x and v3.3.0 */
1557		cdev->can.bittiming_const = &m_can_bittiming_const_31X;
1558		cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
1559
1560		cdev->can.ctrlmode_supported |=
1561			(m_can_niso_supported(cdev) ?
1562			 CAN_CTRLMODE_FD_NON_ISO : 0);
1563		break;
1564	default:
1565		dev_err(cdev->dev, "Unsupported version number: %2d",
1566			cdev->version);
1567		return -EINVAL;
1568	}
1569
1570	if (cdev->ops->init)
1571		cdev->ops->init(cdev);
1572
1573	return 0;
1574}
1575
1576static void m_can_stop(struct net_device *dev)
1577{
1578	struct m_can_classdev *cdev = netdev_priv(dev);
1579
1580	if (!dev->irq) {
1581		dev_dbg(cdev->dev, "Stop hrtimer\n");
1582		hrtimer_cancel(&cdev->hrtimer);
1583	}
1584
1585	/* disable all interrupts */
1586	m_can_disable_all_interrupts(cdev);
1587
1588	/* Set init mode to disengage from the network */
1589	m_can_config_endisable(cdev, true);
1590
1591	/* set the state as STOPPED */
1592	cdev->can.state = CAN_STATE_STOPPED;
1593}
1594
1595static int m_can_close(struct net_device *dev)
1596{
1597	struct m_can_classdev *cdev = netdev_priv(dev);
1598
1599	netif_stop_queue(dev);
1600
1601	if (!cdev->is_peripheral)
1602		napi_disable(&cdev->napi);
1603
1604	m_can_stop(dev);
1605	m_can_clk_stop(cdev);
1606	free_irq(dev->irq, dev);
1607
1608	if (cdev->is_peripheral) {
1609		cdev->tx_skb = NULL;
1610		destroy_workqueue(cdev->tx_wq);
1611		cdev->tx_wq = NULL;
1612		can_rx_offload_disable(&cdev->offload);
1613	}
1614
1615	close_candev(dev);
1616
1617	phy_power_off(cdev->transceiver);
1618
1619	return 0;
1620}
1621
1622static int m_can_next_echo_skb_occupied(struct net_device *dev, int putidx)
1623{
1624	struct m_can_classdev *cdev = netdev_priv(dev);
1625	/*get wrap around for loopback skb index */
1626	unsigned int wrap = cdev->can.echo_skb_max;
1627	int next_idx;
1628
1629	/* calculate next index */
1630	next_idx = (++putidx >= wrap ? 0 : putidx);
1631
1632	/* check if occupied */
1633	return !!cdev->can.echo_skb[next_idx];
1634}
1635
1636static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
1637{
1638	struct canfd_frame *cf = (struct canfd_frame *)cdev->tx_skb->data;
1639	struct net_device *dev = cdev->net;
1640	struct sk_buff *skb = cdev->tx_skb;
1641	struct id_and_dlc fifo_header;
1642	u32 cccr, fdflags;
1643	u32 txfqs;
1644	int err;
1645	int putidx;
1646
1647	cdev->tx_skb = NULL;
1648
1649	/* Generate ID field for TX buffer Element */
1650	/* Common to all supported M_CAN versions */
1651	if (cf->can_id & CAN_EFF_FLAG) {
1652		fifo_header.id = cf->can_id & CAN_EFF_MASK;
1653		fifo_header.id |= TX_BUF_XTD;
1654	} else {
1655		fifo_header.id = ((cf->can_id & CAN_SFF_MASK) << 18);
1656	}
1657
1658	if (cf->can_id & CAN_RTR_FLAG)
1659		fifo_header.id |= TX_BUF_RTR;
1660
1661	if (cdev->version == 30) {
1662		netif_stop_queue(dev);
1663
1664		fifo_header.dlc = can_fd_len2dlc(cf->len) << 16;
1665
1666		/* Write the frame ID, DLC, and payload to the FIFO element. */
1667		err = m_can_fifo_write(cdev, 0, M_CAN_FIFO_ID, &fifo_header, 2);
1668		if (err)
1669			goto out_fail;
1670
1671		err = m_can_fifo_write(cdev, 0, M_CAN_FIFO_DATA,
1672				       cf->data, DIV_ROUND_UP(cf->len, 4));
1673		if (err)
1674			goto out_fail;
1675
1676		if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
1677			cccr = m_can_read(cdev, M_CAN_CCCR);
1678			cccr &= ~CCCR_CMR_MASK;
1679			if (can_is_canfd_skb(skb)) {
1680				if (cf->flags & CANFD_BRS)
1681					cccr |= FIELD_PREP(CCCR_CMR_MASK,
1682							   CCCR_CMR_CANFD_BRS);
1683				else
1684					cccr |= FIELD_PREP(CCCR_CMR_MASK,
1685							   CCCR_CMR_CANFD);
1686			} else {
1687				cccr |= FIELD_PREP(CCCR_CMR_MASK, CCCR_CMR_CAN);
1688			}
1689			m_can_write(cdev, M_CAN_CCCR, cccr);
1690		}
1691		m_can_write(cdev, M_CAN_TXBTIE, 0x1);
1692
1693		can_put_echo_skb(skb, dev, 0, 0);
1694
1695		m_can_write(cdev, M_CAN_TXBAR, 0x1);
1696		/* End of xmit function for version 3.0.x */
1697	} else {
1698		/* Transmit routine for version >= v3.1.x */
1699
1700		txfqs = m_can_read(cdev, M_CAN_TXFQS);
1701
1702		/* Check if FIFO full */
1703		if (_m_can_tx_fifo_full(txfqs)) {
1704			/* This shouldn't happen */
1705			netif_stop_queue(dev);
1706			netdev_warn(dev,
1707				    "TX queue active although FIFO is full.");
1708
1709			if (cdev->is_peripheral) {
1710				kfree_skb(skb);
1711				dev->stats.tx_dropped++;
1712				return NETDEV_TX_OK;
1713			} else {
1714				return NETDEV_TX_BUSY;
1715			}
1716		}
1717
1718		/* get put index for frame */
1719		putidx = FIELD_GET(TXFQS_TFQPI_MASK, txfqs);
1720
1721		/* Construct DLC Field, with CAN-FD configuration.
1722		 * Use the put index of the fifo as the message marker,
1723		 * used in the TX interrupt for sending the correct echo frame.
1724		 */
1725
1726		/* get CAN FD configuration of frame */
1727		fdflags = 0;
1728		if (can_is_canfd_skb(skb)) {
1729			fdflags |= TX_BUF_FDF;
1730			if (cf->flags & CANFD_BRS)
1731				fdflags |= TX_BUF_BRS;
1732		}
1733
1734		fifo_header.dlc = FIELD_PREP(TX_BUF_MM_MASK, putidx) |
1735			FIELD_PREP(TX_BUF_DLC_MASK, can_fd_len2dlc(cf->len)) |
1736			fdflags | TX_BUF_EFC;
1737		err = m_can_fifo_write(cdev, putidx, M_CAN_FIFO_ID, &fifo_header, 2);
1738		if (err)
1739			goto out_fail;
1740
1741		err = m_can_fifo_write(cdev, putidx, M_CAN_FIFO_DATA,
1742				       cf->data, DIV_ROUND_UP(cf->len, 4));
1743		if (err)
1744			goto out_fail;
1745
1746		/* Push loopback echo.
1747		 * Will be looped back on TX interrupt based on message marker
1748		 */
1749		can_put_echo_skb(skb, dev, putidx, 0);
1750
1751		/* Enable TX FIFO element to start transfer  */
1752		m_can_write(cdev, M_CAN_TXBAR, (1 << putidx));
1753
1754		/* stop network queue if fifo full */
1755		if (m_can_tx_fifo_full(cdev) ||
1756		    m_can_next_echo_skb_occupied(dev, putidx))
1757			netif_stop_queue(dev);
1758	}
1759
1760	return NETDEV_TX_OK;
1761
1762out_fail:
1763	netdev_err(dev, "FIFO write returned %d\n", err);
1764	m_can_disable_all_interrupts(cdev);
1765	return NETDEV_TX_BUSY;
1766}
1767
1768static void m_can_tx_work_queue(struct work_struct *ws)
1769{
1770	struct m_can_classdev *cdev = container_of(ws, struct m_can_classdev,
1771						   tx_work);
1772
1773	m_can_tx_handler(cdev);
1774}
1775
1776static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
1777				    struct net_device *dev)
1778{
1779	struct m_can_classdev *cdev = netdev_priv(dev);
1780
1781	if (can_dev_dropped_skb(dev, skb))
1782		return NETDEV_TX_OK;
1783
1784	if (cdev->is_peripheral) {
1785		if (cdev->tx_skb) {
1786			netdev_err(dev, "hard_xmit called while tx busy\n");
1787			return NETDEV_TX_BUSY;
1788		}
1789
1790		if (cdev->can.state == CAN_STATE_BUS_OFF) {
1791			m_can_clean(dev);
1792		} else {
1793			/* Need to stop the queue to avoid numerous requests
1794			 * from being sent.  Suggested improvement is to create
1795			 * a queueing mechanism that will queue the skbs and
1796			 * process them in order.
1797			 */
1798			cdev->tx_skb = skb;
1799			netif_stop_queue(cdev->net);
1800			queue_work(cdev->tx_wq, &cdev->tx_work);
1801		}
1802	} else {
1803		cdev->tx_skb = skb;
1804		return m_can_tx_handler(cdev);
1805	}
1806
1807	return NETDEV_TX_OK;
1808}
1809
1810static enum hrtimer_restart hrtimer_callback(struct hrtimer *timer)
1811{
1812	struct m_can_classdev *cdev = container_of(timer, struct
1813						   m_can_classdev, hrtimer);
1814
1815	m_can_isr(0, cdev->net);
1816
1817	hrtimer_forward_now(timer, ms_to_ktime(HRTIMER_POLL_INTERVAL_MS));
1818
1819	return HRTIMER_RESTART;
1820}
1821
1822static int m_can_open(struct net_device *dev)
1823{
1824	struct m_can_classdev *cdev = netdev_priv(dev);
1825	int err;
1826
1827	err = phy_power_on(cdev->transceiver);
1828	if (err)
1829		return err;
1830
1831	err = m_can_clk_start(cdev);
1832	if (err)
1833		goto out_phy_power_off;
1834
1835	/* open the can device */
1836	err = open_candev(dev);
1837	if (err) {
1838		netdev_err(dev, "failed to open can device\n");
1839		goto exit_disable_clks;
1840	}
1841
1842	if (cdev->is_peripheral)
1843		can_rx_offload_enable(&cdev->offload);
1844
1845	/* register interrupt handler */
1846	if (cdev->is_peripheral) {
1847		cdev->tx_skb = NULL;
1848		cdev->tx_wq = alloc_workqueue("mcan_wq",
1849					      WQ_FREEZABLE | WQ_MEM_RECLAIM, 0);
1850		if (!cdev->tx_wq) {
1851			err = -ENOMEM;
1852			goto out_wq_fail;
1853		}
1854
1855		INIT_WORK(&cdev->tx_work, m_can_tx_work_queue);
1856
1857		err = request_threaded_irq(dev->irq, NULL, m_can_isr,
1858					   IRQF_ONESHOT,
1859					   dev->name, dev);
1860	} else if (dev->irq) {
1861		err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
1862				  dev);
1863	}
1864
1865	if (err < 0) {
1866		netdev_err(dev, "failed to request interrupt\n");
1867		goto exit_irq_fail;
1868	}
1869
1870	/* start the m_can controller */
1871	err = m_can_start(dev);
1872	if (err)
1873		goto exit_irq_fail;
1874
1875	if (!cdev->is_peripheral)
1876		napi_enable(&cdev->napi);
1877
1878	netif_start_queue(dev);
1879
1880	return 0;
1881
1882exit_irq_fail:
1883	if (cdev->is_peripheral)
1884		destroy_workqueue(cdev->tx_wq);
1885out_wq_fail:
1886	if (cdev->is_peripheral)
1887		can_rx_offload_disable(&cdev->offload);
1888	close_candev(dev);
1889exit_disable_clks:
1890	m_can_clk_stop(cdev);
1891out_phy_power_off:
1892	phy_power_off(cdev->transceiver);
1893	return err;
1894}
1895
1896static const struct net_device_ops m_can_netdev_ops = {
1897	.ndo_open = m_can_open,
1898	.ndo_stop = m_can_close,
1899	.ndo_start_xmit = m_can_start_xmit,
1900	.ndo_change_mtu = can_change_mtu,
1901};
1902
1903static const struct ethtool_ops m_can_ethtool_ops = {
1904	.get_ts_info = ethtool_op_get_ts_info,
1905};
1906
1907static int register_m_can_dev(struct net_device *dev)
1908{
1909	dev->flags |= IFF_ECHO;	/* we support local echo */
1910	dev->netdev_ops = &m_can_netdev_ops;
1911	dev->ethtool_ops = &m_can_ethtool_ops;
1912
1913	return register_candev(dev);
1914}
1915
1916int m_can_check_mram_cfg(struct m_can_classdev *cdev, u32 mram_max_size)
1917{
1918	u32 total_size;
1919
1920	total_size = cdev->mcfg[MRAM_TXB].off - cdev->mcfg[MRAM_SIDF].off +
1921			cdev->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
1922	if (total_size > mram_max_size) {
1923		dev_err(cdev->dev, "Total size of mram config(%u) exceeds mram(%u)\n",
1924			total_size, mram_max_size);
1925		return -EINVAL;
1926	}
1927
1928	return 0;
1929}
1930EXPORT_SYMBOL_GPL(m_can_check_mram_cfg);
1931
1932static void m_can_of_parse_mram(struct m_can_classdev *cdev,
1933				const u32 *mram_config_vals)
1934{
1935	cdev->mcfg[MRAM_SIDF].off = mram_config_vals[0];
1936	cdev->mcfg[MRAM_SIDF].num = mram_config_vals[1];
1937	cdev->mcfg[MRAM_XIDF].off = cdev->mcfg[MRAM_SIDF].off +
1938		cdev->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;
1939	cdev->mcfg[MRAM_XIDF].num = mram_config_vals[2];
1940	cdev->mcfg[MRAM_RXF0].off = cdev->mcfg[MRAM_XIDF].off +
1941		cdev->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;
1942	cdev->mcfg[MRAM_RXF0].num = mram_config_vals[3] &
1943		FIELD_MAX(RXFC_FS_MASK);
1944	cdev->mcfg[MRAM_RXF1].off = cdev->mcfg[MRAM_RXF0].off +
1945		cdev->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;
1946	cdev->mcfg[MRAM_RXF1].num = mram_config_vals[4] &
1947		FIELD_MAX(RXFC_FS_MASK);
1948	cdev->mcfg[MRAM_RXB].off = cdev->mcfg[MRAM_RXF1].off +
1949		cdev->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;
1950	cdev->mcfg[MRAM_RXB].num = mram_config_vals[5];
1951	cdev->mcfg[MRAM_TXE].off = cdev->mcfg[MRAM_RXB].off +
1952		cdev->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;
1953	cdev->mcfg[MRAM_TXE].num = mram_config_vals[6];
1954	cdev->mcfg[MRAM_TXB].off = cdev->mcfg[MRAM_TXE].off +
1955		cdev->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;
1956	cdev->mcfg[MRAM_TXB].num = mram_config_vals[7] &
1957		FIELD_MAX(TXBC_NDTB_MASK);
1958
1959	dev_dbg(cdev->dev,
1960		"sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
1961		cdev->mcfg[MRAM_SIDF].off, cdev->mcfg[MRAM_SIDF].num,
1962		cdev->mcfg[MRAM_XIDF].off, cdev->mcfg[MRAM_XIDF].num,
1963		cdev->mcfg[MRAM_RXF0].off, cdev->mcfg[MRAM_RXF0].num,
1964		cdev->mcfg[MRAM_RXF1].off, cdev->mcfg[MRAM_RXF1].num,
1965		cdev->mcfg[MRAM_RXB].off, cdev->mcfg[MRAM_RXB].num,
1966		cdev->mcfg[MRAM_TXE].off, cdev->mcfg[MRAM_TXE].num,
1967		cdev->mcfg[MRAM_TXB].off, cdev->mcfg[MRAM_TXB].num);
1968}
1969
1970int m_can_init_ram(struct m_can_classdev *cdev)
1971{
1972	int end, i, start;
1973	int err = 0;
1974
1975	/* initialize the entire Message RAM in use to avoid possible
1976	 * ECC/parity checksum errors when reading an uninitialized buffer
1977	 */
1978	start = cdev->mcfg[MRAM_SIDF].off;
1979	end = cdev->mcfg[MRAM_TXB].off +
1980		cdev->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
1981
1982	for (i = start; i < end; i += 4) {
1983		err = m_can_fifo_write_no_off(cdev, i, 0x0);
1984		if (err)
1985			break;
1986	}
1987
1988	return err;
1989}
1990EXPORT_SYMBOL_GPL(m_can_init_ram);
1991
1992int m_can_class_get_clocks(struct m_can_classdev *cdev)
1993{
1994	int ret = 0;
1995
1996	cdev->hclk = devm_clk_get(cdev->dev, "hclk");
1997	cdev->cclk = devm_clk_get(cdev->dev, "cclk");
1998
1999	if (IS_ERR(cdev->hclk) || IS_ERR(cdev->cclk)) {
2000		dev_err(cdev->dev, "no clock found\n");
2001		ret = -ENODEV;
2002	}
2003
2004	return ret;
2005}
2006EXPORT_SYMBOL_GPL(m_can_class_get_clocks);
2007
2008struct m_can_classdev *m_can_class_allocate_dev(struct device *dev,
2009						int sizeof_priv)
2010{
2011	struct m_can_classdev *class_dev = NULL;
2012	u32 mram_config_vals[MRAM_CFG_LEN];
2013	struct net_device *net_dev;
2014	u32 tx_fifo_size;
2015	int ret;
2016
2017	ret = fwnode_property_read_u32_array(dev_fwnode(dev),
2018					     "bosch,mram-cfg",
2019					     mram_config_vals,
2020					     sizeof(mram_config_vals) / 4);
2021	if (ret) {
2022		dev_err(dev, "Could not get Message RAM configuration.");
2023		goto out;
2024	}
2025
2026	/* Get TX FIFO size
2027	 * Defines the total amount of echo buffers for loopback
2028	 */
2029	tx_fifo_size = mram_config_vals[7];
2030
2031	/* allocate the m_can device */
2032	net_dev = alloc_candev(sizeof_priv, tx_fifo_size);
2033	if (!net_dev) {
2034		dev_err(dev, "Failed to allocate CAN device");
2035		goto out;
2036	}
2037
2038	class_dev = netdev_priv(net_dev);
2039	class_dev->net = net_dev;
2040	class_dev->dev = dev;
2041	SET_NETDEV_DEV(net_dev, dev);
2042
2043	m_can_of_parse_mram(class_dev, mram_config_vals);
2044out:
2045	return class_dev;
2046}
2047EXPORT_SYMBOL_GPL(m_can_class_allocate_dev);
2048
2049void m_can_class_free_dev(struct net_device *net)
2050{
2051	free_candev(net);
2052}
2053EXPORT_SYMBOL_GPL(m_can_class_free_dev);
2054
2055int m_can_class_register(struct m_can_classdev *cdev)
2056{
2057	int ret;
2058
2059	if (cdev->pm_clock_support) {
2060		ret = m_can_clk_start(cdev);
2061		if (ret)
2062			return ret;
2063	}
2064
2065	if (cdev->is_peripheral) {
2066		ret = can_rx_offload_add_manual(cdev->net, &cdev->offload,
2067						NAPI_POLL_WEIGHT);
2068		if (ret)
2069			goto clk_disable;
2070	}
2071
2072	if (!cdev->net->irq)
2073		cdev->hrtimer.function = &hrtimer_callback;
2074
2075	ret = m_can_dev_setup(cdev);
2076	if (ret)
2077		goto rx_offload_del;
2078
2079	ret = register_m_can_dev(cdev->net);
2080	if (ret) {
2081		dev_err(cdev->dev, "registering %s failed (err=%d)\n",
2082			cdev->net->name, ret);
2083		goto rx_offload_del;
2084	}
2085
2086	of_can_transceiver(cdev->net);
2087
2088	dev_info(cdev->dev, "%s device registered (irq=%d, version=%d)\n",
2089		 KBUILD_MODNAME, cdev->net->irq, cdev->version);
2090
2091	/* Probe finished
2092	 * Stop clocks. They will be reactivated once the M_CAN device is opened
2093	 */
2094	m_can_clk_stop(cdev);
2095
2096	return 0;
2097
2098rx_offload_del:
2099	if (cdev->is_peripheral)
2100		can_rx_offload_del(&cdev->offload);
2101clk_disable:
2102	m_can_clk_stop(cdev);
2103
2104	return ret;
2105}
2106EXPORT_SYMBOL_GPL(m_can_class_register);
2107
2108void m_can_class_unregister(struct m_can_classdev *cdev)
2109{
2110	if (cdev->is_peripheral)
2111		can_rx_offload_del(&cdev->offload);
2112	unregister_candev(cdev->net);
2113}
2114EXPORT_SYMBOL_GPL(m_can_class_unregister);
2115
2116int m_can_class_suspend(struct device *dev)
2117{
2118	struct m_can_classdev *cdev = dev_get_drvdata(dev);
2119	struct net_device *ndev = cdev->net;
2120
2121	if (netif_running(ndev)) {
2122		netif_stop_queue(ndev);
2123		netif_device_detach(ndev);
2124		m_can_stop(ndev);
2125		m_can_clk_stop(cdev);
2126	}
2127
2128	pinctrl_pm_select_sleep_state(dev);
2129
2130	cdev->can.state = CAN_STATE_SLEEPING;
2131
2132	return 0;
2133}
2134EXPORT_SYMBOL_GPL(m_can_class_suspend);
2135
2136int m_can_class_resume(struct device *dev)
2137{
2138	struct m_can_classdev *cdev = dev_get_drvdata(dev);
2139	struct net_device *ndev = cdev->net;
2140
2141	pinctrl_pm_select_default_state(dev);
2142
2143	cdev->can.state = CAN_STATE_ERROR_ACTIVE;
2144
2145	if (netif_running(ndev)) {
2146		int ret;
2147
2148		ret = m_can_clk_start(cdev);
2149		if (ret)
2150			return ret;
2151		ret  = m_can_start(ndev);
2152		if (ret) {
2153			m_can_clk_stop(cdev);
2154
2155			return ret;
2156		}
2157
2158		netif_device_attach(ndev);
2159		netif_start_queue(ndev);
2160	}
2161
2162	return 0;
2163}
2164EXPORT_SYMBOL_GPL(m_can_class_resume);
2165
2166MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
2167MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
2168MODULE_LICENSE("GPL v2");
2169MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");