| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Bhupesh Sharma | 3400 | 56.50% | 1 | 1.28% |
| Thomas Gleixner | 918 | 15.25% | 26 | 33.33% |
| AnilKumar Chimata | 510 | 8.47% | 5 | 6.41% |
| Dario Binacchi | 447 | 7.43% | 8 | 10.26% |
| Thor Thayer | 202 | 3.36% | 1 | 1.28% |
| Jeroen Hofstee | 170 | 2.82% | 2 | 2.56% |
| Marc Kleine-Budde | 140 | 2.33% | 9 | 11.54% |
| Kurt Van Dijck | 55 | 0.91% | 1 | 1.28% |
| J.D. Schroeder | 33 | 0.55% | 1 | 1.28% |
| Roger Quadros | 28 | 0.47% | 1 | 1.28% |
| Pavel Machek | 25 | 0.42% | 3 | 3.85% |
| Markus Pargmann | 22 | 0.37% | 2 | 2.56% |
| Oliver Hartkopp | 17 | 0.28% | 6 | 7.69% |
| Qilong Zhang | 15 | 0.25% | 1 | 1.28% |
| Vincent Mailhol | 12 | 0.20% | 3 | 3.85% |
| Dan Carpenter | 9 | 0.15% | 1 | 1.28% |
| Viktor Babrian | 4 | 0.07% | 1 | 1.28% |
| Eric Dumazet | 3 | 0.05% | 1 | 1.28% |
| Lucas De Marchi | 2 | 0.03% | 1 | 1.28% |
| Andri Yngvason | 2 | 0.03% | 1 | 1.28% |
| Olivier Sobrie | 2 | 0.03% | 1 | 1.28% |
| Jan Altenberg | 1 | 0.02% | 1 | 1.28% |
| Jakub Kiciński | 1 | 0.02% | 1 | 1.28% |
| Total | 6018 | 78 |
/* * CAN bus driver for Bosch C_CAN controller * * Copyright (C) 2010 ST Microelectronics * Bhupesh Sharma <bhupesh.sharma@st.com> * * Borrowed heavily from the C_CAN driver originally written by: * Copyright (C) 2007 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <s.hauer@pengutronix.de> * - Simon Kallweit, intefo AG <simon.kallweit@intefo.ch> * * TX and RX NAPI implementation has been borrowed from at91 CAN driver * written by: * Copyright * (C) 2007 by Hans J. Koch <hjk@hansjkoch.de> * (C) 2008, 2009 by Marc Kleine-Budde <kernel@pengutronix.de> * * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A and B. * Bosch C_CAN user manual can be obtained from: * http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/ * users_manual_c_can.pdf * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/interrupt.h> #include <linux/delay.h> #include <linux/netdevice.h> #include <linux/if_arp.h> #include <linux/if_ether.h> #include <linux/list.h> #include <linux/io.h> #include <linux/pm_runtime.h> #include <linux/pinctrl/consumer.h> #include <linux/can.h> #include <linux/can/dev.h> #include <linux/can/error.h> #include "c_can.h" /* Number of interface registers */ #define IF_ENUM_REG_LEN 11 #define C_CAN_IFACE(reg, iface) (C_CAN_IF1_##reg + (iface) * IF_ENUM_REG_LEN) /* control extension register D_CAN specific */ #define CONTROL_EX_PDR BIT(8) /* control register */ #define CONTROL_SWR BIT(15) #define CONTROL_TEST BIT(7) #define CONTROL_CCE BIT(6) #define CONTROL_DISABLE_AR BIT(5) #define CONTROL_ENABLE_AR (0 << 5) #define CONTROL_EIE BIT(3) #define CONTROL_SIE BIT(2) #define CONTROL_IE BIT(1) #define CONTROL_INIT BIT(0) #define CONTROL_IRQMSK (CONTROL_EIE | CONTROL_IE | CONTROL_SIE) /* test register */ #define TEST_RX BIT(7) #define TEST_TX1 BIT(6) #define TEST_TX2 BIT(5) #define TEST_LBACK BIT(4) #define TEST_SILENT BIT(3) #define TEST_BASIC BIT(2) /* status register */ #define STATUS_PDA BIT(10) #define STATUS_BOFF BIT(7) #define STATUS_EWARN BIT(6) #define STATUS_EPASS BIT(5) #define STATUS_RXOK BIT(4) #define STATUS_TXOK BIT(3) /* error counter register */ #define ERR_CNT_TEC_MASK 0xff #define ERR_CNT_TEC_SHIFT 0 #define ERR_CNT_REC_SHIFT 8 #define ERR_CNT_REC_MASK (0x7f << ERR_CNT_REC_SHIFT) #define ERR_CNT_RP_SHIFT 15 #define ERR_CNT_RP_MASK (0x1 << ERR_CNT_RP_SHIFT) /* bit-timing register */ #define BTR_BRP_MASK 0x3f #define BTR_BRP_SHIFT 0 #define BTR_SJW_SHIFT 6 #define BTR_SJW_MASK (0x3 << BTR_SJW_SHIFT) #define BTR_TSEG1_SHIFT 8 #define BTR_TSEG1_MASK (0xf << BTR_TSEG1_SHIFT) #define BTR_TSEG2_SHIFT 12 #define BTR_TSEG2_MASK (0x7 << BTR_TSEG2_SHIFT) /* interrupt register */ #define INT_STS_PENDING 0x8000 /* brp extension register */ #define BRP_EXT_BRPE_MASK 0x0f #define BRP_EXT_BRPE_SHIFT 0 /* IFx command request */ #define IF_COMR_BUSY BIT(15) /* IFx command mask */ #define IF_COMM_WR BIT(7) #define IF_COMM_MASK BIT(6) #define IF_COMM_ARB BIT(5) #define IF_COMM_CONTROL BIT(4) #define IF_COMM_CLR_INT_PND BIT(3) #define IF_COMM_TXRQST BIT(2) #define IF_COMM_CLR_NEWDAT IF_COMM_TXRQST #define IF_COMM_DATAA BIT(1) #define IF_COMM_DATAB BIT(0) /* TX buffer setup */ #define IF_COMM_TX (IF_COMM_ARB | IF_COMM_CONTROL | \ IF_COMM_TXRQST | \ IF_COMM_DATAA | IF_COMM_DATAB) /* For the low buffers we clear the interrupt bit, but keep newdat */ #define IF_COMM_RCV_LOW (IF_COMM_MASK | IF_COMM_ARB | \ IF_COMM_CONTROL | IF_COMM_CLR_INT_PND | \ IF_COMM_DATAA | IF_COMM_DATAB) /* For the high buffers we clear the interrupt bit and newdat */ #define IF_COMM_RCV_HIGH (IF_COMM_RCV_LOW | IF_COMM_CLR_NEWDAT) /* Receive setup of message objects */ #define IF_COMM_RCV_SETUP (IF_COMM_MASK | IF_COMM_ARB | IF_COMM_CONTROL) /* Invalidation of message objects */ #define IF_COMM_INVAL (IF_COMM_ARB | IF_COMM_CONTROL) /* IFx arbitration */ #define IF_ARB_MSGVAL BIT(31) #define IF_ARB_MSGXTD BIT(30) #define IF_ARB_TRANSMIT BIT(29) /* IFx message control */ #define IF_MCONT_NEWDAT BIT(15) #define IF_MCONT_MSGLST BIT(14) #define IF_MCONT_INTPND BIT(13) #define IF_MCONT_UMASK BIT(12) #define IF_MCONT_TXIE BIT(11) #define IF_MCONT_RXIE BIT(10) #define IF_MCONT_RMTEN BIT(9) #define IF_MCONT_TXRQST BIT(8) #define IF_MCONT_EOB BIT(7) #define IF_MCONT_DLC_MASK 0xf #define IF_MCONT_RCV (IF_MCONT_RXIE | IF_MCONT_UMASK) #define IF_MCONT_RCV_EOB (IF_MCONT_RCV | IF_MCONT_EOB) #define IF_MCONT_TX (IF_MCONT_TXIE | IF_MCONT_EOB) /* Use IF1 in NAPI path and IF2 in TX path */ #define IF_NAPI 0 #define IF_TX 1 /* minimum timeout for checking BUSY status */ #define MIN_TIMEOUT_VALUE 6 /* Wait for ~1 sec for INIT bit */ #define INIT_WAIT_MS 1000 /* c_can lec values */ enum c_can_lec_type { LEC_NO_ERROR = 0, LEC_STUFF_ERROR, LEC_FORM_ERROR, LEC_ACK_ERROR, LEC_BIT1_ERROR, LEC_BIT0_ERROR, LEC_CRC_ERROR, LEC_UNUSED, LEC_MASK = LEC_UNUSED, }; /* c_can error types: * Bus errors (BUS_OFF, ERROR_WARNING, ERROR_PASSIVE) are supported */ enum c_can_bus_error_types { C_CAN_NO_ERROR = 0, C_CAN_BUS_OFF, C_CAN_ERROR_WARNING, C_CAN_ERROR_PASSIVE, }; static const struct can_bittiming_const c_can_bittiming_const = { .name = KBUILD_MODNAME, .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */ .tseg1_max = 16, .tseg2_min = 1, /* Time segment 2 = phase_seg2 */ .tseg2_max = 8, .sjw_max = 4, .brp_min = 1, .brp_max = 1024, /* 6-bit BRP field + 4-bit BRPE field*/ .brp_inc = 1, }; static inline void c_can_pm_runtime_get_sync(const struct c_can_priv *priv) { if (priv->device) pm_runtime_get_sync(priv->device); } static inline void c_can_pm_runtime_put_sync(const struct c_can_priv *priv) { if (priv->device) pm_runtime_put_sync(priv->device); } static inline void c_can_reset_ram(const struct c_can_priv *priv, bool enable) { if (priv->raminit) priv->raminit(priv, enable); } static void c_can_irq_control(struct c_can_priv *priv, bool enable) { u32 ctrl = priv->read_reg(priv, C_CAN_CTRL_REG) & ~CONTROL_IRQMSK; if (enable) ctrl |= CONTROL_IRQMSK; priv->write_reg(priv, C_CAN_CTRL_REG, ctrl); } static void c_can_obj_update(struct net_device *dev, int iface, u32 cmd, u32 obj) { struct c_can_priv *priv = netdev_priv(dev); int cnt, reg = C_CAN_IFACE(COMREQ_REG, iface); priv->write_reg32(priv, reg, (cmd << 16) | obj); for (cnt = MIN_TIMEOUT_VALUE; cnt; cnt--) { if (!(priv->read_reg(priv, reg) & IF_COMR_BUSY)) return; udelay(1); } netdev_err(dev, "Updating object timed out\n"); } static inline void c_can_object_get(struct net_device *dev, int iface, u32 obj, u32 cmd) { c_can_obj_update(dev, iface, cmd, obj); } static inline void c_can_object_put(struct net_device *dev, int iface, u32 obj, u32 cmd) { c_can_obj_update(dev, iface, cmd | IF_COMM_WR, obj); } /* Note: According to documentation clearing TXIE while MSGVAL is set * is not allowed, but works nicely on C/DCAN. And that lowers the I/O * load significantly. */ static void c_can_inval_tx_object(struct net_device *dev, int iface, int obj) { struct c_can_priv *priv = netdev_priv(dev); priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), 0); c_can_object_put(dev, iface, obj, IF_COMM_INVAL); } static void c_can_inval_msg_object(struct net_device *dev, int iface, int obj) { struct c_can_priv *priv = netdev_priv(dev); priv->write_reg32(priv, C_CAN_IFACE(ARB1_REG, iface), 0); c_can_inval_tx_object(dev, iface, obj); } static void c_can_setup_tx_object(struct net_device *dev, int iface, struct can_frame *frame, int idx) { struct c_can_priv *priv = netdev_priv(dev); u16 ctrl = IF_MCONT_TX | frame->len; bool rtr = frame->can_id & CAN_RTR_FLAG; u32 arb = IF_ARB_MSGVAL; int i; if (frame->can_id & CAN_EFF_FLAG) { arb |= frame->can_id & CAN_EFF_MASK; arb |= IF_ARB_MSGXTD; } else { arb |= (frame->can_id & CAN_SFF_MASK) << 18; } if (!rtr) arb |= IF_ARB_TRANSMIT; /* If we change the DIR bit, we need to invalidate the buffer * first, i.e. clear the MSGVAL flag in the arbiter. */ if (rtr != (bool)test_bit(idx, &priv->tx_dir)) { u32 obj = idx + priv->msg_obj_tx_first; c_can_inval_msg_object(dev, iface, obj); change_bit(idx, &priv->tx_dir); } priv->write_reg32(priv, C_CAN_IFACE(ARB1_REG, iface), arb); priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), ctrl); if (priv->type == BOSCH_D_CAN) { u32 data = 0, dreg = C_CAN_IFACE(DATA1_REG, iface); for (i = 0; i < frame->len; i += 4, dreg += 2) { data = (u32)frame->data[i]; data |= (u32)frame->data[i + 1] << 8; data |= (u32)frame->data[i + 2] << 16; data |= (u32)frame->data[i + 3] << 24; priv->write_reg32(priv, dreg, data); } } else { for (i = 0; i < frame->len; i += 2) { priv->write_reg(priv, C_CAN_IFACE(DATA1_REG, iface) + i / 2, frame->data[i] | (frame->data[i + 1] << 8)); } } } static int c_can_handle_lost_msg_obj(struct net_device *dev, int iface, int objno, u32 ctrl) { struct net_device_stats *stats = &dev->stats; struct c_can_priv *priv = netdev_priv(dev); struct can_frame *frame; struct sk_buff *skb; ctrl &= ~(IF_MCONT_MSGLST | IF_MCONT_INTPND | IF_MCONT_NEWDAT); priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), ctrl); c_can_object_put(dev, iface, objno, IF_COMM_CONTROL); stats->rx_errors++; stats->rx_over_errors++; /* create an error msg */ skb = alloc_can_err_skb(dev, &frame); if (unlikely(!skb)) return 0; frame->can_id |= CAN_ERR_CRTL; frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; netif_receive_skb(skb); return 1; } static int c_can_read_msg_object(struct net_device *dev, int iface, u32 ctrl) { struct net_device_stats *stats = &dev->stats; struct c_can_priv *priv = netdev_priv(dev); struct can_frame *frame; struct sk_buff *skb; u32 arb, data; skb = alloc_can_skb(dev, &frame); if (!skb) { stats->rx_dropped++; return -ENOMEM; } frame->len = can_cc_dlc2len(ctrl & 0x0F); arb = priv->read_reg32(priv, C_CAN_IFACE(ARB1_REG, iface)); if (arb & IF_ARB_MSGXTD) frame->can_id = (arb & CAN_EFF_MASK) | CAN_EFF_FLAG; else frame->can_id = (arb >> 18) & CAN_SFF_MASK; if (arb & IF_ARB_TRANSMIT) { frame->can_id |= CAN_RTR_FLAG; } else { int i, dreg = C_CAN_IFACE(DATA1_REG, iface); if (priv->type == BOSCH_D_CAN) { for (i = 0; i < frame->len; i += 4, dreg += 2) { data = priv->read_reg32(priv, dreg); frame->data[i] = data; frame->data[i + 1] = data >> 8; frame->data[i + 2] = data >> 16; frame->data[i + 3] = data >> 24; } } else { for (i = 0; i < frame->len; i += 2, dreg++) { data = priv->read_reg(priv, dreg); frame->data[i] = data; frame->data[i + 1] = data >> 8; } } stats->rx_bytes += frame->len; } stats->rx_packets++; netif_receive_skb(skb); return 0; } static void c_can_setup_receive_object(struct net_device *dev, int iface, u32 obj, u32 mask, u32 id, u32 mcont) { struct c_can_priv *priv = netdev_priv(dev); mask |= BIT(29); priv->write_reg32(priv, C_CAN_IFACE(MASK1_REG, iface), mask); id |= IF_ARB_MSGVAL; priv->write_reg32(priv, C_CAN_IFACE(ARB1_REG, iface), id); priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), mcont); c_can_object_put(dev, iface, obj, IF_COMM_RCV_SETUP); } static bool c_can_tx_busy(const struct c_can_priv *priv, const struct c_can_tx_ring *tx_ring) { if (c_can_get_tx_free(priv, tx_ring) > 0) return false; netif_stop_queue(priv->dev); /* Memory barrier before checking tx_free (head and tail) */ smp_mb(); if (c_can_get_tx_free(priv, tx_ring) == 0) { netdev_dbg(priv->dev, "Stopping tx-queue (tx_head=0x%08x, tx_tail=0x%08x, len=%d).\n", tx_ring->head, tx_ring->tail, tx_ring->head - tx_ring->tail); return true; } netif_start_queue(priv->dev); return false; } static netdev_tx_t c_can_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct can_frame *frame = (struct can_frame *)skb->data; struct c_can_priv *priv = netdev_priv(dev); struct c_can_tx_ring *tx_ring = &priv->tx; u32 idx, obj, cmd = IF_COMM_TX; if (can_dev_dropped_skb(dev, skb)) return NETDEV_TX_OK; if (c_can_tx_busy(priv, tx_ring)) return NETDEV_TX_BUSY; idx = c_can_get_tx_head(tx_ring); tx_ring->head++; if (c_can_get_tx_free(priv, tx_ring) == 0) netif_stop_queue(dev); if (idx < c_can_get_tx_tail(tx_ring)) cmd &= ~IF_COMM_TXRQST; /* Cache the message */ /* Store the message in the interface so we can call * can_put_echo_skb(). We must do this before we enable * transmit as we might race against do_tx(). */ c_can_setup_tx_object(dev, IF_TX, frame, idx); can_put_echo_skb(skb, dev, idx, 0); obj = idx + priv->msg_obj_tx_first; c_can_object_put(dev, IF_TX, obj, cmd); return NETDEV_TX_OK; } static int c_can_wait_for_ctrl_init(struct net_device *dev, struct c_can_priv *priv, u32 init) { int retry = 0; while (init != (priv->read_reg(priv, C_CAN_CTRL_REG) & CONTROL_INIT)) { udelay(10); if (retry++ > 1000) { netdev_err(dev, "CCTRL: set CONTROL_INIT failed\n"); return -EIO; } } return 0; } static int c_can_set_bittiming(struct net_device *dev) { unsigned int reg_btr, reg_brpe, ctrl_save; u8 brp, brpe, sjw, tseg1, tseg2; u32 ten_bit_brp; struct c_can_priv *priv = netdev_priv(dev); const struct can_bittiming *bt = &priv->can.bittiming; int res; /* c_can provides a 6-bit brp and 4-bit brpe fields */ ten_bit_brp = bt->brp - 1; brp = ten_bit_brp & BTR_BRP_MASK; brpe = ten_bit_brp >> 6; sjw = bt->sjw - 1; tseg1 = bt->prop_seg + bt->phase_seg1 - 1; tseg2 = bt->phase_seg2 - 1; reg_btr = brp | (sjw << BTR_SJW_SHIFT) | (tseg1 << BTR_TSEG1_SHIFT) | (tseg2 << BTR_TSEG2_SHIFT); reg_brpe = brpe & BRP_EXT_BRPE_MASK; netdev_info(dev, "setting BTR=%04x BRPE=%04x\n", reg_btr, reg_brpe); ctrl_save = priv->read_reg(priv, C_CAN_CTRL_REG); ctrl_save &= ~CONTROL_INIT; priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_CCE | CONTROL_INIT); res = c_can_wait_for_ctrl_init(dev, priv, CONTROL_INIT); if (res) return res; priv->write_reg(priv, C_CAN_BTR_REG, reg_btr); priv->write_reg(priv, C_CAN_BRPEXT_REG, reg_brpe); priv->write_reg(priv, C_CAN_CTRL_REG, ctrl_save); return c_can_wait_for_ctrl_init(dev, priv, 0); } /* Configure C_CAN message objects for Tx and Rx purposes: * C_CAN provides a total of 32 message objects that can be configured * either for Tx or Rx purposes. Here the first 16 message objects are used as * a reception FIFO. The end of reception FIFO is signified by the EoB bit * being SET. The remaining 16 message objects are kept aside for Tx purposes. * See user guide document for further details on configuring message * objects. */ static void c_can_configure_msg_objects(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); int i; /* first invalidate all message objects */ for (i = priv->msg_obj_rx_first; i <= priv->msg_obj_num; i++) c_can_inval_msg_object(dev, IF_NAPI, i); /* setup receive message objects */ for (i = priv->msg_obj_rx_first; i < priv->msg_obj_rx_last; i++) c_can_setup_receive_object(dev, IF_NAPI, i, 0, 0, IF_MCONT_RCV); c_can_setup_receive_object(dev, IF_NAPI, priv->msg_obj_rx_last, 0, 0, IF_MCONT_RCV_EOB); } static int c_can_software_reset(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); int retry = 0; if (priv->type != BOSCH_D_CAN) return 0; priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_SWR | CONTROL_INIT); while (priv->read_reg(priv, C_CAN_CTRL_REG) & CONTROL_SWR) { msleep(20); if (retry++ > 100) { netdev_err(dev, "CCTRL: software reset failed\n"); return -EIO; } } return 0; } /* Configure C_CAN chip: * - enable/disable auto-retransmission * - set operating mode * - configure message objects */ static int c_can_chip_config(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); struct c_can_tx_ring *tx_ring = &priv->tx; int err; err = c_can_software_reset(dev); if (err) return err; /* enable automatic retransmission */ priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_ENABLE_AR); if ((priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) && (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)) { /* loopback + silent mode : useful for hot self-test */ priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_TEST); priv->write_reg(priv, C_CAN_TEST_REG, TEST_LBACK | TEST_SILENT); } else if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { /* loopback mode : useful for self-test function */ priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_TEST); priv->write_reg(priv, C_CAN_TEST_REG, TEST_LBACK); } else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) { /* silent mode : bus-monitoring mode */ priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_TEST); priv->write_reg(priv, C_CAN_TEST_REG, TEST_SILENT); } /* configure message objects */ c_can_configure_msg_objects(dev); /* set a `lec` value so that we can check for updates later */ priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED); /* Clear all internal status */ tx_ring->head = 0; tx_ring->tail = 0; priv->tx_dir = 0; /* set bittiming params */ return c_can_set_bittiming(dev); } static int c_can_start(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); int err; struct pinctrl *p; /* basic c_can configuration */ err = c_can_chip_config(dev); if (err) return err; /* Setup the command for new messages */ priv->comm_rcv_high = priv->type != BOSCH_D_CAN ? IF_COMM_RCV_LOW : IF_COMM_RCV_HIGH; priv->can.state = CAN_STATE_ERROR_ACTIVE; /* Attempt to use "active" if available else use "default" */ p = pinctrl_get_select(priv->device, "active"); if (!IS_ERR(p)) pinctrl_put(p); else pinctrl_pm_select_default_state(priv->device); return 0; } static void c_can_stop(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); c_can_irq_control(priv, false); /* put ctrl to init on stop to end ongoing transmission */ priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_INIT); /* deactivate pins */ pinctrl_pm_select_sleep_state(dev->dev.parent); priv->can.state = CAN_STATE_STOPPED; } static int c_can_set_mode(struct net_device *dev, enum can_mode mode) { struct c_can_priv *priv = netdev_priv(dev); int err; switch (mode) { case CAN_MODE_START: err = c_can_start(dev); if (err) return err; netif_wake_queue(dev); c_can_irq_control(priv, true); break; default: return -EOPNOTSUPP; } return 0; } static int __c_can_get_berr_counter(const struct net_device *dev, struct can_berr_counter *bec) { unsigned int reg_err_counter; struct c_can_priv *priv = netdev_priv(dev); reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG); bec->rxerr = (reg_err_counter & ERR_CNT_REC_MASK) >> ERR_CNT_REC_SHIFT; bec->txerr = reg_err_counter & ERR_CNT_TEC_MASK; return 0; } static int c_can_get_berr_counter(const struct net_device *dev, struct can_berr_counter *bec) { struct c_can_priv *priv = netdev_priv(dev); int err; c_can_pm_runtime_get_sync(priv); err = __c_can_get_berr_counter(dev, bec); c_can_pm_runtime_put_sync(priv); return err; } static void c_can_do_tx(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); struct c_can_tx_ring *tx_ring = &priv->tx; struct net_device_stats *stats = &dev->stats; u32 idx, obj, pkts = 0, bytes = 0, pend; u8 tail; if (priv->msg_obj_tx_last > 32) pend = priv->read_reg32(priv, C_CAN_INTPND3_REG); else pend = priv->read_reg(priv, C_CAN_INTPND2_REG); while ((idx = ffs(pend))) { idx--; pend &= ~BIT(idx); obj = idx + priv->msg_obj_tx_first; /* We use IF_NAPI interface instead of IF_TX because we * are called from c_can_poll(), which runs inside * NAPI. We are not transmitting. */ c_can_inval_tx_object(dev, IF_NAPI, obj); bytes += can_get_echo_skb(dev, idx, NULL); pkts++; } if (!pkts) return; tx_ring->tail += pkts; if (c_can_get_tx_free(priv, tx_ring)) { /* Make sure that anybody stopping the queue after * this sees the new tx_ring->tail. */ smp_mb(); netif_wake_queue(priv->dev); } stats->tx_bytes += bytes; stats->tx_packets += pkts; tail = c_can_get_tx_tail(tx_ring); if (priv->type == BOSCH_D_CAN && tail == 0) { u8 head = c_can_get_tx_head(tx_ring); /* Start transmission for all cached messages */ for (idx = tail; idx < head; idx++) { obj = idx + priv->msg_obj_tx_first; c_can_object_put(dev, IF_NAPI, obj, IF_COMM_TXRQST); } } } /* If we have a gap in the pending bits, that means we either * raced with the hardware or failed to readout all upper * objects in the last run due to quota limit. */ static u32 c_can_adjust_pending(u32 pend, u32 rx_mask) { u32 weight, lasts; if (pend == rx_mask) return pend; /* If the last set bit is larger than the number of pending * bits we have a gap. */ weight = hweight32(pend); lasts = fls(pend); /* If the bits are linear, nothing to do */ if (lasts == weight) return pend; /* Find the first set bit after the gap. We walk backwards * from the last set bit. */ for (lasts--; pend & BIT(lasts - 1); lasts--) ; return pend & ~GENMASK(lasts - 1, 0); } static inline void c_can_rx_object_get(struct net_device *dev, struct c_can_priv *priv, u32 obj) { c_can_object_get(dev, IF_NAPI, obj, priv->comm_rcv_high); } static inline void c_can_rx_finalize(struct net_device *dev, struct c_can_priv *priv, u32 obj) { if (priv->type != BOSCH_D_CAN) c_can_object_get(dev, IF_NAPI, obj, IF_COMM_CLR_NEWDAT); } static int c_can_read_objects(struct net_device *dev, struct c_can_priv *priv, u32 pend, int quota) { u32 pkts = 0, ctrl, obj; while ((obj = ffs(pend)) && quota > 0) { pend &= ~BIT(obj - 1); c_can_rx_object_get(dev, priv, obj); ctrl = priv->read_reg(priv, C_CAN_IFACE(MSGCTRL_REG, IF_NAPI)); if (ctrl & IF_MCONT_MSGLST) { int n; n = c_can_handle_lost_msg_obj(dev, IF_NAPI, obj, ctrl); pkts += n; quota -= n; continue; } /* This really should not happen, but this covers some * odd HW behaviour. Do not remove that unless you * want to brick your machine. */ if (!(ctrl & IF_MCONT_NEWDAT)) continue; /* read the data from the message object */ c_can_read_msg_object(dev, IF_NAPI, ctrl); c_can_rx_finalize(dev, priv, obj); pkts++; quota--; } return pkts; } static inline u32 c_can_get_pending(struct c_can_priv *priv) { u32 pend; if (priv->msg_obj_rx_last > 16) pend = priv->read_reg32(priv, C_CAN_NEWDAT1_REG); else pend = priv->read_reg(priv, C_CAN_NEWDAT1_REG); return pend; } /* theory of operation: * * c_can core saves a received CAN message into the first free message * object it finds free (starting with the lowest). Bits NEWDAT and * INTPND are set for this message object indicating that a new message * has arrived. * * We clear the newdat bit right away. * * This can result in packet reordering when the readout is slow. */ static int c_can_do_rx_poll(struct net_device *dev, int quota) { struct c_can_priv *priv = netdev_priv(dev); u32 pkts = 0, pend = 0, toread, n; while (quota > 0) { if (!pend) { pend = c_can_get_pending(priv); if (!pend) break; /* If the pending field has a gap, handle the * bits above the gap first. */ toread = c_can_adjust_pending(pend, priv->msg_obj_rx_mask); } else { toread = pend; } /* Remove the bits from pend */ pend &= ~toread; /* Read the objects */ n = c_can_read_objects(dev, priv, toread, quota); pkts += n; quota -= n; } return pkts; } static int c_can_handle_state_change(struct net_device *dev, enum c_can_bus_error_types error_type) { unsigned int reg_err_counter; unsigned int rx_err_passive; struct c_can_priv *priv = netdev_priv(dev); struct can_frame *cf; struct sk_buff *skb; struct can_berr_counter bec; switch (error_type) { case C_CAN_NO_ERROR: priv->can.state = CAN_STATE_ERROR_ACTIVE; break; case C_CAN_ERROR_WARNING: /* error warning state */ priv->can.can_stats.error_warning++; priv->can.state = CAN_STATE_ERROR_WARNING; break; case C_CAN_ERROR_PASSIVE: /* error passive state */ priv->can.can_stats.error_passive++; priv->can.state = CAN_STATE_ERROR_PASSIVE; break; case C_CAN_BUS_OFF: /* bus-off state */ priv->can.state = CAN_STATE_BUS_OFF; priv->can.can_stats.bus_off++; break; default: break; } /* propagate the error condition to the CAN stack */ skb = alloc_can_err_skb(dev, &cf); if (unlikely(!skb)) return 0; __c_can_get_berr_counter(dev, &bec); reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG); rx_err_passive = (reg_err_counter & ERR_CNT_RP_MASK) >> ERR_CNT_RP_SHIFT; switch (error_type) { case C_CAN_NO_ERROR: cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT; cf->data[1] = CAN_ERR_CRTL_ACTIVE; cf->data[6] = bec.txerr; cf->data[7] = bec.rxerr; break; case C_CAN_ERROR_WARNING: /* error warning state */ cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT; cf->data[1] = (bec.txerr > bec.rxerr) ? CAN_ERR_CRTL_TX_WARNING : CAN_ERR_CRTL_RX_WARNING; cf->data[6] = bec.txerr; cf->data[7] = bec.rxerr; break; case C_CAN_ERROR_PASSIVE: /* error passive state */ cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT; if (rx_err_passive) cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE; if (bec.txerr > 127) cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE; cf->data[6] = bec.txerr; cf->data[7] = bec.rxerr; break; case C_CAN_BUS_OFF: /* bus-off state */ cf->can_id |= CAN_ERR_BUSOFF; can_bus_off(dev); break; default: break; } netif_receive_skb(skb); return 1; } static int c_can_handle_bus_err(struct net_device *dev, enum c_can_lec_type lec_type) { struct c_can_priv *priv = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; struct can_frame *cf; struct sk_buff *skb; /* early exit if no lec update or no error. * no lec update means that no CAN bus event has been detected * since CPU wrote 0x7 value to status reg. */ if (lec_type == LEC_UNUSED || lec_type == LEC_NO_ERROR) return 0; if (!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) return 0; /* common for all type of bus errors */ priv->can.can_stats.bus_error++; stats->rx_errors++; /* propagate the error condition to the CAN stack */ skb = alloc_can_err_skb(dev, &cf); if (unlikely(!skb)) return 0; /* check for 'last error code' which tells us the * type of the last error to occur on the CAN bus */ cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; switch (lec_type) { case LEC_STUFF_ERROR: netdev_dbg(dev, "stuff error\n"); cf->data[2] |= CAN_ERR_PROT_STUFF; break; case LEC_FORM_ERROR: netdev_dbg(dev, "form error\n"); cf->data[2] |= CAN_ERR_PROT_FORM; break; case LEC_ACK_ERROR: netdev_dbg(dev, "ack error\n"); cf->data[3] = CAN_ERR_PROT_LOC_ACK; break; case LEC_BIT1_ERROR: netdev_dbg(dev, "bit1 error\n"); cf->data[2] |= CAN_ERR_PROT_BIT1; break; case LEC_BIT0_ERROR: netdev_dbg(dev, "bit0 error\n"); cf->data[2] |= CAN_ERR_PROT_BIT0; break; case LEC_CRC_ERROR: netdev_dbg(dev, "CRC error\n"); cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; break; default: break; } netif_receive_skb(skb); return 1; } static int c_can_poll(struct napi_struct *napi, int quota) { struct net_device *dev = napi->dev; struct c_can_priv *priv = netdev_priv(dev); u16 curr, last = priv->last_status; int work_done = 0; /* Only read the status register if a status interrupt was pending */ if (atomic_xchg(&priv->sie_pending, 0)) { priv->last_status = priv->read_reg(priv, C_CAN_STS_REG); curr = priv->last_status; /* Ack status on C_CAN. D_CAN is self clearing */ if (priv->type != BOSCH_D_CAN) priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED); } else { /* no change detected ... */ curr = last; } /* handle state changes */ if ((curr & STATUS_EWARN) && (!(last & STATUS_EWARN))) { netdev_dbg(dev, "entered error warning state\n"); work_done += c_can_handle_state_change(dev, C_CAN_ERROR_WARNING); } if ((curr & STATUS_EPASS) && (!(last & STATUS_EPASS))) { netdev_dbg(dev, "entered error passive state\n"); work_done += c_can_handle_state_change(dev, C_CAN_ERROR_PASSIVE); } if ((curr & STATUS_BOFF) && (!(last & STATUS_BOFF))) { netdev_dbg(dev, "entered bus off state\n"); work_done += c_can_handle_state_change(dev, C_CAN_BUS_OFF); goto end; } /* handle bus recovery events */ if ((!(curr & STATUS_BOFF)) && (last & STATUS_BOFF)) { netdev_dbg(dev, "left bus off state\n"); work_done += c_can_handle_state_change(dev, C_CAN_ERROR_PASSIVE); } if ((!(curr & STATUS_EPASS)) && (last & STATUS_EPASS)) { netdev_dbg(dev, "left error passive state\n"); work_done += c_can_handle_state_change(dev, C_CAN_ERROR_WARNING); } if ((!(curr & STATUS_EWARN)) && (last & STATUS_EWARN)) { netdev_dbg(dev, "left error warning state\n"); work_done += c_can_handle_state_change(dev, C_CAN_NO_ERROR); } /* handle lec errors on the bus */ work_done += c_can_handle_bus_err(dev, curr & LEC_MASK); /* Handle Tx/Rx events. We do this unconditionally */ work_done += c_can_do_rx_poll(dev, (quota - work_done)); c_can_do_tx(dev); end: if (work_done < quota) { napi_complete_done(napi, work_done); /* enable all IRQs if we are not in bus off state */ if (priv->can.state != CAN_STATE_BUS_OFF) c_can_irq_control(priv, true); } return work_done; } static irqreturn_t c_can_isr(int irq, void *dev_id) { struct net_device *dev = (struct net_device *)dev_id; struct c_can_priv *priv = netdev_priv(dev); int reg_int; reg_int = priv->read_reg(priv, C_CAN_INT_REG); if (!reg_int) return IRQ_NONE; /* save for later use */ if (reg_int & INT_STS_PENDING) atomic_set(&priv->sie_pending, 1); /* disable all interrupts and schedule the NAPI */ c_can_irq_control(priv, false); napi_schedule(&priv->napi); return IRQ_HANDLED; } static int c_can_open(struct net_device *dev) { int err; struct c_can_priv *priv = netdev_priv(dev); c_can_pm_runtime_get_sync(priv); c_can_reset_ram(priv, true); /* open the can device */ err = open_candev(dev); if (err) { netdev_err(dev, "failed to open can device\n"); goto exit_open_fail; } /* register interrupt handler */ err = request_irq(dev->irq, &c_can_isr, IRQF_SHARED, dev->name, dev); if (err < 0) { netdev_err(dev, "failed to request interrupt\n"); goto exit_irq_fail; } /* start the c_can controller */ err = c_can_start(dev); if (err) goto exit_start_fail; napi_enable(&priv->napi); /* enable status change, error and module interrupts */ c_can_irq_control(priv, true); netif_start_queue(dev); return 0; exit_start_fail: free_irq(dev->irq, dev); exit_irq_fail: close_candev(dev); exit_open_fail: c_can_reset_ram(priv, false); c_can_pm_runtime_put_sync(priv); return err; } static int c_can_close(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); netif_stop_queue(dev); napi_disable(&priv->napi); c_can_stop(dev); free_irq(dev->irq, dev); close_candev(dev); c_can_reset_ram(priv, false); c_can_pm_runtime_put_sync(priv); return 0; } struct net_device *alloc_c_can_dev(int msg_obj_num) { struct net_device *dev; struct c_can_priv *priv; int msg_obj_tx_num = msg_obj_num / 2; dev = alloc_candev(sizeof(*priv), msg_obj_tx_num); if (!dev) return NULL; priv = netdev_priv(dev); priv->msg_obj_num = msg_obj_num; priv->msg_obj_rx_num = msg_obj_num - msg_obj_tx_num; priv->msg_obj_rx_first = 1; priv->msg_obj_rx_last = priv->msg_obj_rx_first + priv->msg_obj_rx_num - 1; priv->msg_obj_rx_mask = GENMASK(priv->msg_obj_rx_num - 1, 0); priv->msg_obj_tx_num = msg_obj_tx_num; priv->msg_obj_tx_first = priv->msg_obj_rx_last + 1; priv->msg_obj_tx_last = priv->msg_obj_tx_first + priv->msg_obj_tx_num - 1; priv->tx.head = 0; priv->tx.tail = 0; priv->tx.obj_num = msg_obj_tx_num; netif_napi_add_weight(dev, &priv->napi, c_can_poll, priv->msg_obj_rx_num); priv->dev = dev; priv->can.bittiming_const = &c_can_bittiming_const; priv->can.do_set_mode = c_can_set_mode; priv->can.do_get_berr_counter = c_can_get_berr_counter; priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_BERR_REPORTING; return dev; } EXPORT_SYMBOL_GPL(alloc_c_can_dev); #ifdef CONFIG_PM int c_can_power_down(struct net_device *dev) { u32 val; unsigned long time_out; struct c_can_priv *priv = netdev_priv(dev); if (!(dev->flags & IFF_UP)) return 0; WARN_ON(priv->type != BOSCH_D_CAN); /* set PDR value so the device goes to power down mode */ val = priv->read_reg(priv, C_CAN_CTRL_EX_REG); val |= CONTROL_EX_PDR; priv->write_reg(priv, C_CAN_CTRL_EX_REG, val); /* Wait for the PDA bit to get set */ time_out = jiffies + msecs_to_jiffies(INIT_WAIT_MS); while (!(priv->read_reg(priv, C_CAN_STS_REG) & STATUS_PDA) && time_after(time_out, jiffies)) cpu_relax(); if (time_after(jiffies, time_out)) return -ETIMEDOUT; c_can_stop(dev); c_can_reset_ram(priv, false); c_can_pm_runtime_put_sync(priv); return 0; } EXPORT_SYMBOL_GPL(c_can_power_down); int c_can_power_up(struct net_device *dev) { u32 val; unsigned long time_out; struct c_can_priv *priv = netdev_priv(dev); int ret; if (!(dev->flags & IFF_UP)) return 0; WARN_ON(priv->type != BOSCH_D_CAN); c_can_pm_runtime_get_sync(priv); c_can_reset_ram(priv, true); /* Clear PDR and INIT bits */ val = priv->read_reg(priv, C_CAN_CTRL_EX_REG); val &= ~CONTROL_EX_PDR; priv->write_reg(priv, C_CAN_CTRL_EX_REG, val); val = priv->read_reg(priv, C_CAN_CTRL_REG); val &= ~CONTROL_INIT; priv->write_reg(priv, C_CAN_CTRL_REG, val); /* Wait for the PDA bit to get clear */ time_out = jiffies + msecs_to_jiffies(INIT_WAIT_MS); while ((priv->read_reg(priv, C_CAN_STS_REG) & STATUS_PDA) && time_after(time_out, jiffies)) cpu_relax(); if (time_after(jiffies, time_out)) { ret = -ETIMEDOUT; goto err_out; } ret = c_can_start(dev); if (ret) goto err_out; c_can_irq_control(priv, true); return 0; err_out: c_can_reset_ram(priv, false); c_can_pm_runtime_put_sync(priv); return ret; } EXPORT_SYMBOL_GPL(c_can_power_up); #endif void free_c_can_dev(struct net_device *dev) { struct c_can_priv *priv = netdev_priv(dev); netif_napi_del(&priv->napi); free_candev(dev); } EXPORT_SYMBOL_GPL(free_c_can_dev); static const struct net_device_ops c_can_netdev_ops = { .ndo_open = c_can_open, .ndo_stop = c_can_close, .ndo_start_xmit = c_can_start_xmit, .ndo_change_mtu = can_change_mtu, }; int register_c_can_dev(struct net_device *dev) { /* Deactivate pins to prevent DRA7 DCAN IP from being * stuck in transition when module is disabled. * Pins are activated in c_can_start() and deactivated * in c_can_stop() */ pinctrl_pm_select_sleep_state(dev->dev.parent); dev->flags |= IFF_ECHO; /* we support local echo */ dev->netdev_ops = &c_can_netdev_ops; dev->ethtool_ops = &c_can_ethtool_ops; return register_candev(dev); } EXPORT_SYMBOL_GPL(register_c_can_dev); void unregister_c_can_dev(struct net_device *dev) { unregister_candev(dev); } EXPORT_SYMBOL_GPL(unregister_c_can_dev); MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>"); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("CAN bus driver for Bosch C_CAN controller");
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