diff options
Diffstat (limited to 'drivers/net/can/c_can/c_can.c')
| -rw-r--r-- | drivers/net/can/c_can/c_can.c | 1317 |
1 files changed, 0 insertions, 1317 deletions
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c deleted file mode 100644 index 606b7d8ffe13..000000000000 --- a/drivers/net/can/c_can/c_can.c +++ /dev/null @@ -1,1317 +0,0 @@ -/* - * 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 <linux/can/led.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_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) - -/* 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 for RX and IF2 for TX - */ -#define IF_RX 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 - -/* napi related */ -#define C_CAN_NAPI_WEIGHT C_CAN_MSG_OBJ_RX_NUM - -/* 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_enable(const struct c_can_priv *priv) -{ - if (priv->device) - pm_runtime_enable(priv->device); -} - -static inline void c_can_pm_runtime_disable(const struct c_can_priv *priv) -{ - if (priv->device) - pm_runtime_disable(priv->device); -} - -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_reg(priv, C_CAN_IFACE(ARB1_REG, iface), 0); - priv->write_reg(priv, C_CAN_IFACE(ARB2_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->can_dlc; - 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 + C_CAN_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->can_dlc; 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->can_dlc; i += 2) { - priv->write_reg(priv, - C_CAN_IFACE(DATA1_REG, iface) + i / 2, - frame->data[i] | - (frame->data[i + 1] << 8)); - } - } -} - -static inline void c_can_activate_all_lower_rx_msg_obj(struct net_device *dev, - int iface) -{ - int i; - - for (i = C_CAN_MSG_OBJ_RX_FIRST; i <= C_CAN_MSG_RX_LOW_LAST; i++) - c_can_object_get(dev, iface, i, IF_COMM_CLR_NEWDAT); -} - -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->can_dlc = get_can_dlc(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->can_dlc; 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->can_dlc; i += 2, dreg++) { - data = priv->read_reg(priv, dreg); - frame->data[i] = data; - frame->data[i + 1] = data >> 8; - } - } - } - - stats->rx_packets++; - stats->rx_bytes += frame->can_dlc; - - 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 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); - u32 idx, obj; - - if (can_dropped_invalid_skb(dev, skb)) - return NETDEV_TX_OK; - /* - * This is not a FIFO. C/D_CAN sends out the buffers - * prioritized. The lowest buffer number wins. - */ - idx = fls(atomic_read(&priv->tx_active)); - obj = idx + C_CAN_MSG_OBJ_TX_FIRST; - - /* If this is the last buffer, stop the xmit queue */ - if (idx == C_CAN_MSG_OBJ_TX_NUM - 1) - netif_stop_queue(dev); - /* - * 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); - priv->dlc[idx] = frame->can_dlc; - can_put_echo_skb(skb, dev, idx); - - /* Update the active bits */ - atomic_add((1 << idx), &priv->tx_active); - /* Start transmission */ - c_can_object_put(dev, IF_TX, obj, IF_COMM_TX); - - 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) -{ - int i; - - /* first invalidate all message objects */ - for (i = C_CAN_MSG_OBJ_RX_FIRST; i <= C_CAN_NO_OF_OBJECTS; i++) - c_can_inval_msg_object(dev, IF_RX, i); - - /* setup receive message objects */ - for (i = C_CAN_MSG_OBJ_RX_FIRST; i < C_CAN_MSG_OBJ_RX_LAST; i++) - c_can_setup_receive_object(dev, IF_RX, i, 0, 0, IF_MCONT_RCV); - - c_can_setup_receive_object(dev, IF_RX, C_CAN_MSG_OBJ_RX_LAST, 0, 0, - IF_MCONT_RCV_EOB); -} - -/* - * 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); - - /* 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 */ - atomic_set(&priv->tx_active, 0); - priv->rxmasked = 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 net_device_stats *stats = &dev->stats; - u32 idx, obj, pkts = 0, bytes = 0, pend, clr; - - clr = pend = priv->read_reg(priv, C_CAN_INTPND2_REG); - - while ((idx = ffs(pend))) { - idx--; - pend &= ~(1 << idx); - obj = idx + C_CAN_MSG_OBJ_TX_FIRST; - c_can_inval_tx_object(dev, IF_RX, obj); - can_get_echo_skb(dev, idx); - bytes += priv->dlc[idx]; - pkts++; - } - - /* Clear the bits in the tx_active mask */ - atomic_sub(clr, &priv->tx_active); - - if (clr & (1 << (C_CAN_MSG_OBJ_TX_NUM - 1))) - netif_wake_queue(dev); - - if (pkts) { - stats->tx_bytes += bytes; - stats->tx_packets += pkts; - can_led_event(dev, CAN_LED_EVENT_TX); - } -} - -/* - * 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 weight, lasts; - - if (pend == RECEIVE_OBJECT_BITS) - 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 & (1 << (lasts - 1)); lasts--); - - return pend & ~((1 << lasts) - 1); -} - -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_RX, 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_RX, 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_RX)); - - if (ctrl & IF_MCONT_MSGLST) { - int n = c_can_handle_lost_msg_obj(dev, IF_RX, 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_RX, 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 = 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. To work-around this issue, we keep two groups of message - * objects whose partitioning is defined by C_CAN_MSG_OBJ_RX_SPLIT. - * - * 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; - - /* - * It is faster to read only one 16bit register. This is only possible - * for a maximum number of 16 objects. - */ - BUILD_BUG_ON_MSG(C_CAN_MSG_OBJ_RX_LAST > 16, - "Implementation does not support more message objects than 16"); - - 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); - } 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; - } - - if (pkts) - can_led_event(dev, CAN_LED_EVENT_RX); - - 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 net_device_stats *stats = &dev->stats; - struct can_frame *cf; - struct sk_buff *skb; - struct can_berr_counter bec; - - switch (error_type) { - 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_ERROR_WARNING: - /* error warning state */ - cf->can_id |= CAN_ERR_CRTL; - 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; - 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; - } - - stats->rx_packets++; - stats->rx_bytes += cf->can_dlc; - 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; - } - - stats->rx_packets++; - stats->rx_bytes += cf->can_dlc; - 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; - - priv->last_status = curr = priv->read_reg(priv, C_CAN_STS_REG); - /* 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); - - /* 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"); - priv->can.state = CAN_STATE_ERROR_ACTIVE; - } - if ((!(curr & STATUS_EPASS)) && (last & STATUS_EPASS)) { - netdev_dbg(dev, "left error passive state\n"); - priv->can.state = CAN_STATE_ERROR_ACTIVE; - } - - /* 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); - - if (!priv->read_reg(priv, C_CAN_INT_REG)) - return IRQ_NONE; - - /* 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; - - can_led_event(dev, CAN_LED_EVENT_OPEN); - - 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); - - can_led_event(dev, CAN_LED_EVENT_STOP); - - return 0; -} - -struct net_device *alloc_c_can_dev(void) -{ - struct net_device *dev; - struct c_can_priv *priv; - - dev = alloc_candev(sizeof(struct c_can_priv), C_CAN_MSG_OBJ_TX_NUM); - if (!dev) - return NULL; - - priv = netdev_priv(dev); - netif_napi_add(dev, &priv->napi, c_can_poll, C_CAN_NAPI_WEIGHT); - - 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)) - return -ETIMEDOUT; - - ret = c_can_start(dev); - if (!ret) - c_can_irq_control(priv, true); - - 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) -{ - struct c_can_priv *priv = netdev_priv(dev); - int err; - - /* 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); - - c_can_pm_runtime_enable(priv); - - dev->flags |= IFF_ECHO; /* we support local echo */ - dev->netdev_ops = &c_can_netdev_ops; - - err = register_candev(dev); - if (err) - c_can_pm_runtime_disable(priv); - else - devm_can_led_init(dev); - - return err; -} -EXPORT_SYMBOL_GPL(register_c_can_dev); - -void unregister_c_can_dev(struct net_device *dev) -{ - struct c_can_priv *priv = netdev_priv(dev); - - unregister_candev(dev); - - c_can_pm_runtime_disable(priv); -} -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"); |