diff options
Diffstat (limited to 'drivers/net/can/m_can/m_can.c')
| -rw-r--r-- | drivers/net/can/m_can/m_can.c | 1202 |
1 files changed, 1202 insertions, 0 deletions
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c new file mode 100644 index 000000000000..10d571eaed85 --- /dev/null +++ b/drivers/net/can/m_can/m_can.c @@ -0,0 +1,1202 @@ +/* + * CAN bus driver for Bosch M_CAN controller + * + * Copyright (C) 2014 Freescale Semiconductor, Inc. + * Dong Aisheng <b29396@freescale.com> + * + * Bosch M_CAN user manual can be obtained from: + * http://www.bosch-semiconductors.de/media/pdf_1/ipmodules_1/m_can/ + * mcan_users_manual_v302.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/clk.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> + +#include <linux/can/dev.h> + +/* napi related */ +#define M_CAN_NAPI_WEIGHT 64 + +/* message ram configuration data length */ +#define MRAM_CFG_LEN 8 + +/* registers definition */ +enum m_can_reg { + M_CAN_CREL = 0x0, + M_CAN_ENDN = 0x4, + M_CAN_CUST = 0x8, + M_CAN_FBTP = 0xc, + M_CAN_TEST = 0x10, + M_CAN_RWD = 0x14, + M_CAN_CCCR = 0x18, + M_CAN_BTP = 0x1c, + M_CAN_TSCC = 0x20, + M_CAN_TSCV = 0x24, + M_CAN_TOCC = 0x28, + M_CAN_TOCV = 0x2c, + M_CAN_ECR = 0x40, + M_CAN_PSR = 0x44, + M_CAN_IR = 0x50, + M_CAN_IE = 0x54, + M_CAN_ILS = 0x58, + M_CAN_ILE = 0x5c, + M_CAN_GFC = 0x80, + M_CAN_SIDFC = 0x84, + M_CAN_XIDFC = 0x88, + M_CAN_XIDAM = 0x90, + M_CAN_HPMS = 0x94, + M_CAN_NDAT1 = 0x98, + M_CAN_NDAT2 = 0x9c, + M_CAN_RXF0C = 0xa0, + M_CAN_RXF0S = 0xa4, + M_CAN_RXF0A = 0xa8, + M_CAN_RXBC = 0xac, + M_CAN_RXF1C = 0xb0, + M_CAN_RXF1S = 0xb4, + M_CAN_RXF1A = 0xb8, + M_CAN_RXESC = 0xbc, + M_CAN_TXBC = 0xc0, + M_CAN_TXFQS = 0xc4, + M_CAN_TXESC = 0xc8, + M_CAN_TXBRP = 0xcc, + M_CAN_TXBAR = 0xd0, + M_CAN_TXBCR = 0xd4, + M_CAN_TXBTO = 0xd8, + M_CAN_TXBCF = 0xdc, + M_CAN_TXBTIE = 0xe0, + M_CAN_TXBCIE = 0xe4, + M_CAN_TXEFC = 0xf0, + M_CAN_TXEFS = 0xf4, + M_CAN_TXEFA = 0xf8, +}; + +/* m_can lec values */ +enum m_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, +}; + +enum m_can_mram_cfg { + MRAM_SIDF = 0, + MRAM_XIDF, + MRAM_RXF0, + MRAM_RXF1, + MRAM_RXB, + MRAM_TXE, + MRAM_TXB, + MRAM_CFG_NUM, +}; + +/* Test Register (TEST) */ +#define TEST_LBCK BIT(4) + +/* CC Control Register(CCCR) */ +#define CCCR_TEST BIT(7) +#define CCCR_MON BIT(5) +#define CCCR_CCE BIT(1) +#define CCCR_INIT BIT(0) + +/* Bit Timing & Prescaler Register (BTP) */ +#define BTR_BRP_MASK 0x3ff +#define BTR_BRP_SHIFT 16 +#define BTR_TSEG1_SHIFT 8 +#define BTR_TSEG1_MASK (0x3f << BTR_TSEG1_SHIFT) +#define BTR_TSEG2_SHIFT 4 +#define BTR_TSEG2_MASK (0xf << BTR_TSEG2_SHIFT) +#define BTR_SJW_SHIFT 0 +#define BTR_SJW_MASK 0xf + +/* Error Counter Register(ECR) */ +#define ECR_RP BIT(15) +#define ECR_REC_SHIFT 8 +#define ECR_REC_MASK (0x7f << ECR_REC_SHIFT) +#define ECR_TEC_SHIFT 0 +#define ECR_TEC_MASK 0xff + +/* Protocol Status Register(PSR) */ +#define PSR_BO BIT(7) +#define PSR_EW BIT(6) +#define PSR_EP BIT(5) +#define PSR_LEC_MASK 0x7 + +/* Interrupt Register(IR) */ +#define IR_ALL_INT 0xffffffff +#define IR_STE BIT(31) +#define IR_FOE BIT(30) +#define IR_ACKE BIT(29) +#define IR_BE BIT(28) +#define IR_CRCE BIT(27) +#define IR_WDI BIT(26) +#define IR_BO BIT(25) +#define IR_EW BIT(24) +#define IR_EP BIT(23) +#define IR_ELO BIT(22) +#define IR_BEU BIT(21) +#define IR_BEC BIT(20) +#define IR_DRX BIT(19) +#define IR_TOO BIT(18) +#define IR_MRAF BIT(17) +#define IR_TSW BIT(16) +#define IR_TEFL BIT(15) +#define IR_TEFF BIT(14) +#define IR_TEFW BIT(13) +#define IR_TEFN BIT(12) +#define IR_TFE BIT(11) +#define IR_TCF BIT(10) +#define IR_TC BIT(9) +#define IR_HPM BIT(8) +#define IR_RF1L BIT(7) +#define IR_RF1F BIT(6) +#define IR_RF1W BIT(5) +#define IR_RF1N BIT(4) +#define IR_RF0L BIT(3) +#define IR_RF0F BIT(2) +#define IR_RF0W BIT(1) +#define IR_RF0N BIT(0) +#define IR_ERR_STATE (IR_BO | IR_EW | IR_EP) +#define IR_ERR_LEC (IR_STE | IR_FOE | IR_ACKE | IR_BE | IR_CRCE) +#define IR_ERR_BUS (IR_ERR_LEC | IR_WDI | IR_ELO | IR_BEU | \ + IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | \ + IR_RF1L | IR_RF0L) +#define IR_ERR_ALL (IR_ERR_STATE | IR_ERR_BUS) + +/* Interrupt Line Select (ILS) */ +#define ILS_ALL_INT0 0x0 +#define ILS_ALL_INT1 0xFFFFFFFF + +/* Interrupt Line Enable (ILE) */ +#define ILE_EINT0 BIT(0) +#define ILE_EINT1 BIT(1) + +/* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */ +#define RXFC_FWM_OFF 24 +#define RXFC_FWM_MASK 0x7f +#define RXFC_FWM_1 (1 << RXFC_FWM_OFF) +#define RXFC_FS_OFF 16 +#define RXFC_FS_MASK 0x7f + +/* Rx FIFO 0/1 Status (RXF0S/RXF1S) */ +#define RXFS_RFL BIT(25) +#define RXFS_FF BIT(24) +#define RXFS_FPI_OFF 16 +#define RXFS_FPI_MASK 0x3f0000 +#define RXFS_FGI_OFF 8 +#define RXFS_FGI_MASK 0x3f00 +#define RXFS_FFL_MASK 0x7f + +/* Rx Buffer / FIFO Element Size Configuration (RXESC) */ +#define M_CAN_RXESC_8BYTES 0x0 + +/* Tx Buffer Configuration(TXBC) */ +#define TXBC_NDTB_OFF 16 +#define TXBC_NDTB_MASK 0x3f + +/* Tx Buffer Element Size Configuration(TXESC) */ +#define TXESC_TBDS_8BYTES 0x0 + +/* Tx Event FIFO Con.guration (TXEFC) */ +#define TXEFC_EFS_OFF 16 +#define TXEFC_EFS_MASK 0x3f + +/* Message RAM Configuration (in bytes) */ +#define SIDF_ELEMENT_SIZE 4 +#define XIDF_ELEMENT_SIZE 8 +#define RXF0_ELEMENT_SIZE 16 +#define RXF1_ELEMENT_SIZE 16 +#define RXB_ELEMENT_SIZE 16 +#define TXE_ELEMENT_SIZE 8 +#define TXB_ELEMENT_SIZE 16 + +/* Message RAM Elements */ +#define M_CAN_FIFO_ID 0x0 +#define M_CAN_FIFO_DLC 0x4 +#define M_CAN_FIFO_DATA(n) (0x8 + ((n) << 2)) + +/* Rx Buffer Element */ +#define RX_BUF_ESI BIT(31) +#define RX_BUF_XTD BIT(30) +#define RX_BUF_RTR BIT(29) + +/* Tx Buffer Element */ +#define TX_BUF_XTD BIT(30) +#define TX_BUF_RTR BIT(29) + +/* address offset and element number for each FIFO/Buffer in the Message RAM */ +struct mram_cfg { + u16 off; + u8 num; +}; + +/* m_can private data structure */ +struct m_can_priv { + struct can_priv can; /* must be the first member */ + struct napi_struct napi; + struct net_device *dev; + struct device *device; + struct clk *hclk; + struct clk *cclk; + void __iomem *base; + u32 irqstatus; + + /* message ram configuration */ + void __iomem *mram_base; + struct mram_cfg mcfg[MRAM_CFG_NUM]; +}; + +static inline u32 m_can_read(const struct m_can_priv *priv, enum m_can_reg reg) +{ + return readl(priv->base + reg); +} + +static inline void m_can_write(const struct m_can_priv *priv, + enum m_can_reg reg, u32 val) +{ + writel(val, priv->base + reg); +} + +static inline u32 m_can_fifo_read(const struct m_can_priv *priv, + u32 fgi, unsigned int offset) +{ + return readl(priv->mram_base + priv->mcfg[MRAM_RXF0].off + + fgi * RXF0_ELEMENT_SIZE + offset); +} + +static inline void m_can_fifo_write(const struct m_can_priv *priv, + u32 fpi, unsigned int offset, u32 val) +{ + return writel(val, priv->mram_base + priv->mcfg[MRAM_TXB].off + + fpi * TXB_ELEMENT_SIZE + offset); +} + +static inline void m_can_config_endisable(const struct m_can_priv *priv, + bool enable) +{ + u32 cccr = m_can_read(priv, M_CAN_CCCR); + u32 timeout = 10; + u32 val = 0; + + if (enable) { + /* enable m_can configuration */ + m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT); + /* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */ + m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE); + } else { + m_can_write(priv, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE)); + } + + /* there's a delay for module initialization */ + if (enable) + val = CCCR_INIT | CCCR_CCE; + + while ((m_can_read(priv, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) { + if (timeout == 0) { + netdev_warn(priv->dev, "Failed to init module\n"); + return; + } + timeout--; + udelay(1); + } +} + +static inline void m_can_enable_all_interrupts(const struct m_can_priv *priv) +{ + m_can_write(priv, M_CAN_ILE, ILE_EINT0 | ILE_EINT1); +} + +static inline void m_can_disable_all_interrupts(const struct m_can_priv *priv) +{ + m_can_write(priv, M_CAN_ILE, 0x0); +} + +static void m_can_read_fifo(const struct net_device *dev, struct can_frame *cf, + u32 rxfs) +{ + struct m_can_priv *priv = netdev_priv(dev); + u32 id, fgi; + + /* calculate the fifo get index for where to read data */ + fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_OFF; + id = m_can_fifo_read(priv, fgi, M_CAN_FIFO_ID); + if (id & RX_BUF_XTD) + cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG; + else + cf->can_id = (id >> 18) & CAN_SFF_MASK; + + if (id & RX_BUF_RTR) { + cf->can_id |= CAN_RTR_FLAG; + } else { + id = m_can_fifo_read(priv, fgi, M_CAN_FIFO_DLC); + cf->can_dlc = get_can_dlc((id >> 16) & 0x0F); + *(u32 *)(cf->data + 0) = m_can_fifo_read(priv, fgi, + M_CAN_FIFO_DATA(0)); + *(u32 *)(cf->data + 4) = m_can_fifo_read(priv, fgi, + M_CAN_FIFO_DATA(1)); + } + + /* acknowledge rx fifo 0 */ + m_can_write(priv, M_CAN_RXF0A, fgi); +} + +static int m_can_do_rx_poll(struct net_device *dev, int quota) +{ + struct m_can_priv *priv = netdev_priv(dev); + struct net_device_stats *stats = &dev->stats; + struct sk_buff *skb; + struct can_frame *frame; + u32 pkts = 0; + u32 rxfs; + + rxfs = m_can_read(priv, M_CAN_RXF0S); + if (!(rxfs & RXFS_FFL_MASK)) { + netdev_dbg(dev, "no messages in fifo0\n"); + return 0; + } + + while ((rxfs & RXFS_FFL_MASK) && (quota > 0)) { + if (rxfs & RXFS_RFL) + netdev_warn(dev, "Rx FIFO 0 Message Lost\n"); + + skb = alloc_can_skb(dev, &frame); + if (!skb) { + stats->rx_dropped++; + return pkts; + } + + m_can_read_fifo(dev, frame, rxfs); + + stats->rx_packets++; + stats->rx_bytes += frame->can_dlc; + + netif_receive_skb(skb); + + quota--; + pkts++; + rxfs = m_can_read(priv, M_CAN_RXF0S); + } + + if (pkts) + can_led_event(dev, CAN_LED_EVENT_RX); + + return pkts; +} + +static int m_can_handle_lost_msg(struct net_device *dev) +{ + struct net_device_stats *stats = &dev->stats; + struct sk_buff *skb; + struct can_frame *frame; + + netdev_err(dev, "msg lost in rxf0\n"); + + stats->rx_errors++; + stats->rx_over_errors++; + + 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 m_can_handle_lec_err(struct net_device *dev, + enum m_can_lec_type lec_type) +{ + struct m_can_priv *priv = netdev_priv(dev); + struct net_device_stats *stats = &dev->stats; + struct can_frame *cf; + struct sk_buff *skb; + + 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; + cf->data[2] |= CAN_ERR_PROT_UNSPEC; + + 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 | + CAN_ERR_PROT_LOC_ACK_DEL); + 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 | + CAN_ERR_PROT_LOC_CRC_DEL); + break; + default: + break; + } + + stats->rx_packets++; + stats->rx_bytes += cf->can_dlc; + netif_receive_skb(skb); + + return 1; +} + +static int m_can_get_berr_counter(const struct net_device *dev, + struct can_berr_counter *bec) +{ + struct m_can_priv *priv = netdev_priv(dev); + unsigned int ecr; + int err; + + err = clk_prepare_enable(priv->hclk); + if (err) + return err; + + err = clk_prepare_enable(priv->cclk); + if (err) { + clk_disable_unprepare(priv->hclk); + return err; + } + + ecr = m_can_read(priv, M_CAN_ECR); + bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT; + bec->txerr = ecr & ECR_TEC_MASK; + + clk_disable_unprepare(priv->cclk); + clk_disable_unprepare(priv->hclk); + + return 0; +} + +static int m_can_handle_state_change(struct net_device *dev, + enum can_state new_state) +{ + struct m_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; + unsigned int ecr; + + switch (new_state) { + case CAN_STATE_ERROR_ACTIVE: + /* error warning state */ + priv->can.can_stats.error_warning++; + priv->can.state = CAN_STATE_ERROR_WARNING; + break; + case CAN_STATE_ERROR_PASSIVE: + /* error passive state */ + priv->can.can_stats.error_passive++; + priv->can.state = CAN_STATE_ERROR_PASSIVE; + break; + case CAN_STATE_BUS_OFF: + /* bus-off state */ + priv->can.state = CAN_STATE_BUS_OFF; + m_can_disable_all_interrupts(priv); + can_bus_off(dev); + break; + default: + break; + } + + /* propagate the error condition to the CAN stack */ + skb = alloc_can_err_skb(dev, &cf); + if (unlikely(!skb)) + return 0; + + m_can_get_berr_counter(dev, &bec); + + switch (new_state) { + case CAN_STATE_ERROR_ACTIVE: + /* 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 CAN_STATE_ERROR_PASSIVE: + /* error passive state */ + cf->can_id |= CAN_ERR_CRTL; + ecr = m_can_read(priv, M_CAN_ECR); + if (ecr & ECR_RP) + 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 CAN_STATE_BUS_OFF: + /* bus-off state */ + cf->can_id |= CAN_ERR_BUSOFF; + break; + default: + break; + } + + stats->rx_packets++; + stats->rx_bytes += cf->can_dlc; + netif_receive_skb(skb); + + return 1; +} + +static int m_can_handle_state_errors(struct net_device *dev, u32 psr) +{ + struct m_can_priv *priv = netdev_priv(dev); + int work_done = 0; + + if ((psr & PSR_EW) && + (priv->can.state != CAN_STATE_ERROR_WARNING)) { + netdev_dbg(dev, "entered error warning state\n"); + work_done += m_can_handle_state_change(dev, + CAN_STATE_ERROR_WARNING); + } + + if ((psr & PSR_EP) && + (priv->can.state != CAN_STATE_ERROR_PASSIVE)) { + netdev_dbg(dev, "entered error warning state\n"); + work_done += m_can_handle_state_change(dev, + CAN_STATE_ERROR_PASSIVE); + } + + if ((psr & PSR_BO) && + (priv->can.state != CAN_STATE_BUS_OFF)) { + netdev_dbg(dev, "entered error warning state\n"); + work_done += m_can_handle_state_change(dev, + CAN_STATE_BUS_OFF); + } + + return work_done; +} + +static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus) +{ + if (irqstatus & IR_WDI) + netdev_err(dev, "Message RAM Watchdog event due to missing READY\n"); + if (irqstatus & IR_BEU) + netdev_err(dev, "Error Logging Overflow\n"); + if (irqstatus & IR_BEU) + netdev_err(dev, "Bit Error Uncorrected\n"); + if (irqstatus & IR_BEC) + netdev_err(dev, "Bit Error Corrected\n"); + if (irqstatus & IR_TOO) + netdev_err(dev, "Timeout reached\n"); + if (irqstatus & IR_MRAF) + netdev_err(dev, "Message RAM access failure occurred\n"); +} + +static inline bool is_lec_err(u32 psr) +{ + psr &= LEC_UNUSED; + + return psr && (psr != LEC_UNUSED); +} + +static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus, + u32 psr) +{ + struct m_can_priv *priv = netdev_priv(dev); + int work_done = 0; + + if (irqstatus & IR_RF0L) + work_done += m_can_handle_lost_msg(dev); + + /* handle lec errors on the bus */ + if ((priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) && + is_lec_err(psr)) + work_done += m_can_handle_lec_err(dev, psr & LEC_UNUSED); + + /* other unproccessed error interrupts */ + m_can_handle_other_err(dev, irqstatus); + + return work_done; +} + +static int m_can_poll(struct napi_struct *napi, int quota) +{ + struct net_device *dev = napi->dev; + struct m_can_priv *priv = netdev_priv(dev); + int work_done = 0; + u32 irqstatus, psr; + + irqstatus = priv->irqstatus | m_can_read(priv, M_CAN_IR); + if (!irqstatus) + goto end; + + psr = m_can_read(priv, M_CAN_PSR); + if (irqstatus & IR_ERR_STATE) + work_done += m_can_handle_state_errors(dev, psr); + + if (irqstatus & IR_ERR_BUS) + work_done += m_can_handle_bus_errors(dev, irqstatus, psr); + + if (irqstatus & IR_RF0N) + work_done += m_can_do_rx_poll(dev, (quota - work_done)); + + if (work_done < quota) { + napi_complete(napi); + m_can_enable_all_interrupts(priv); + } + +end: + return work_done; +} + +static irqreturn_t m_can_isr(int irq, void *dev_id) +{ + struct net_device *dev = (struct net_device *)dev_id; + struct m_can_priv *priv = netdev_priv(dev); + struct net_device_stats *stats = &dev->stats; + u32 ir; + + ir = m_can_read(priv, M_CAN_IR); + if (!ir) + return IRQ_NONE; + + /* ACK all irqs */ + if (ir & IR_ALL_INT) + m_can_write(priv, M_CAN_IR, ir); + + /* schedule NAPI in case of + * - rx IRQ + * - state change IRQ + * - bus error IRQ and bus error reporting + */ + if ((ir & IR_RF0N) || (ir & IR_ERR_ALL)) { + priv->irqstatus = ir; + m_can_disable_all_interrupts(priv); + napi_schedule(&priv->napi); + } + + /* transmission complete interrupt */ + if (ir & IR_TC) { + stats->tx_bytes += can_get_echo_skb(dev, 0); + stats->tx_packets++; + can_led_event(dev, CAN_LED_EVENT_TX); + netif_wake_queue(dev); + } + + return IRQ_HANDLED; +} + +static const struct can_bittiming_const m_can_bittiming_const = { + .name = KBUILD_MODNAME, + .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */ + .tseg1_max = 64, + .tseg2_min = 1, /* Time segment 2 = phase_seg2 */ + .tseg2_max = 16, + .sjw_max = 16, + .brp_min = 1, + .brp_max = 1024, + .brp_inc = 1, +}; + +static int m_can_set_bittiming(struct net_device *dev) +{ + struct m_can_priv *priv = netdev_priv(dev); + const struct can_bittiming *bt = &priv->can.bittiming; + u16 brp, sjw, tseg1, tseg2; + u32 reg_btp; + + brp = bt->brp - 1; + sjw = bt->sjw - 1; + tseg1 = bt->prop_seg + bt->phase_seg1 - 1; + tseg2 = bt->phase_seg2 - 1; + reg_btp = (brp << BTR_BRP_SHIFT) | (sjw << BTR_SJW_SHIFT) | + (tseg1 << BTR_TSEG1_SHIFT) | (tseg2 << BTR_TSEG2_SHIFT); + m_can_write(priv, M_CAN_BTP, reg_btp); + netdev_dbg(dev, "setting BTP 0x%x\n", reg_btp); + + return 0; +} + +/* Configure M_CAN chip: + * - set rx buffer/fifo element size + * - configure rx fifo + * - accept non-matching frame into fifo 0 + * - configure tx buffer + * - configure mode + * - setup bittiming + */ +static void m_can_chip_config(struct net_device *dev) +{ + struct m_can_priv *priv = netdev_priv(dev); + u32 cccr, test; + + m_can_config_endisable(priv, true); + + /* RX Buffer/FIFO Element Size 8 bytes data field */ + m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_8BYTES); + + /* Accept Non-matching Frames Into FIFO 0 */ + m_can_write(priv, M_CAN_GFC, 0x0); + + /* only support one Tx Buffer currently */ + m_can_write(priv, M_CAN_TXBC, (1 << TXBC_NDTB_OFF) | + priv->mcfg[MRAM_TXB].off); + + /* only support 8 bytes firstly */ + m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_8BYTES); + + m_can_write(priv, M_CAN_TXEFC, (1 << TXEFC_EFS_OFF) | + priv->mcfg[MRAM_TXE].off); + + /* rx fifo configuration, blocking mode, fifo size 1 */ + m_can_write(priv, M_CAN_RXF0C, + (priv->mcfg[MRAM_RXF0].num << RXFC_FS_OFF) | + RXFC_FWM_1 | priv->mcfg[MRAM_RXF0].off); + + m_can_write(priv, M_CAN_RXF1C, + (priv->mcfg[MRAM_RXF1].num << RXFC_FS_OFF) | + RXFC_FWM_1 | priv->mcfg[MRAM_RXF1].off); + + cccr = m_can_read(priv, M_CAN_CCCR); + cccr &= ~(CCCR_TEST | CCCR_MON); + test = m_can_read(priv, M_CAN_TEST); + test &= ~TEST_LBCK; + + if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) + cccr |= CCCR_MON; + + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) { + cccr |= CCCR_TEST; + test |= TEST_LBCK; + } + + m_can_write(priv, M_CAN_CCCR, cccr); + m_can_write(priv, M_CAN_TEST, test); + + /* enable interrupts */ + m_can_write(priv, M_CAN_IR, IR_ALL_INT); + if (!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) + m_can_write(priv, M_CAN_IE, IR_ALL_INT & ~IR_ERR_LEC); + else + m_can_write(priv, M_CAN_IE, IR_ALL_INT); + + /* route all interrupts to INT0 */ + m_can_write(priv, M_CAN_ILS, ILS_ALL_INT0); + + /* set bittiming params */ + m_can_set_bittiming(dev); + + m_can_config_endisable(priv, false); +} + +static void m_can_start(struct net_device *dev) +{ + struct m_can_priv *priv = netdev_priv(dev); + + /* basic m_can configuration */ + m_can_chip_config(dev); + + priv->can.state = CAN_STATE_ERROR_ACTIVE; + + m_can_enable_all_interrupts(priv); +} + +static int m_can_set_mode(struct net_device *dev, enum can_mode mode) +{ + switch (mode) { + case CAN_MODE_START: + m_can_start(dev); + netif_wake_queue(dev); + break; + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static void free_m_can_dev(struct net_device *dev) +{ + free_candev(dev); +} + +static struct net_device *alloc_m_can_dev(void) +{ + struct net_device *dev; + struct m_can_priv *priv; + + dev = alloc_candev(sizeof(*priv), 1); + if (!dev) + return NULL; + + priv = netdev_priv(dev); + netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT); + + priv->dev = dev; + priv->can.bittiming_const = &m_can_bittiming_const; + priv->can.do_set_mode = m_can_set_mode; + priv->can.do_get_berr_counter = m_can_get_berr_counter; + priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | + CAN_CTRLMODE_LISTENONLY | + CAN_CTRLMODE_BERR_REPORTING; + + return dev; +} + +static int m_can_open(struct net_device *dev) +{ + struct m_can_priv *priv = netdev_priv(dev); + int err; + + err = clk_prepare_enable(priv->hclk); + if (err) + return err; + + err = clk_prepare_enable(priv->cclk); + if (err) + goto exit_disable_hclk; + + /* open the can device */ + err = open_candev(dev); + if (err) { + netdev_err(dev, "failed to open can device\n"); + goto exit_disable_cclk; + } + + /* register interrupt handler */ + err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name, + dev); + if (err < 0) { + netdev_err(dev, "failed to request interrupt\n"); + goto exit_irq_fail; + } + + /* start the m_can controller */ + m_can_start(dev); + + can_led_event(dev, CAN_LED_EVENT_OPEN); + napi_enable(&priv->napi); + netif_start_queue(dev); + + return 0; + +exit_irq_fail: + close_candev(dev); +exit_disable_cclk: + clk_disable_unprepare(priv->cclk); +exit_disable_hclk: + clk_disable_unprepare(priv->hclk); + return err; +} + +static void m_can_stop(struct net_device *dev) +{ + struct m_can_priv *priv = netdev_priv(dev); + + /* disable all interrupts */ + m_can_disable_all_interrupts(priv); + + clk_disable_unprepare(priv->hclk); + clk_disable_unprepare(priv->cclk); + + /* set the state as STOPPED */ + priv->can.state = CAN_STATE_STOPPED; +} + +static int m_can_close(struct net_device *dev) +{ + struct m_can_priv *priv = netdev_priv(dev); + + netif_stop_queue(dev); + napi_disable(&priv->napi); + m_can_stop(dev); + free_irq(dev->irq, dev); + close_candev(dev); + can_led_event(dev, CAN_LED_EVENT_STOP); + + return 0; +} + +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct m_can_priv *priv = netdev_priv(dev); + struct can_frame *cf = (struct can_frame *)skb->data; + u32 id; + + if (can_dropped_invalid_skb(dev, skb)) + return NETDEV_TX_OK; + + netif_stop_queue(dev); + + if (cf->can_id & CAN_EFF_FLAG) { + id = cf->can_id & CAN_EFF_MASK; + id |= TX_BUF_XTD; + } else { + id = ((cf->can_id & CAN_SFF_MASK) << 18); + } + + if (cf->can_id & CAN_RTR_FLAG) + id |= TX_BUF_RTR; + + /* message ram configuration */ + m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id); + m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, cf->can_dlc << 16); + m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(0), *(u32 *)(cf->data + 0)); + m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(1), *(u32 *)(cf->data + 4)); + can_put_echo_skb(skb, dev, 0); + + /* enable first TX buffer to start transfer */ + m_can_write(priv, M_CAN_TXBTIE, 0x1); + m_can_write(priv, M_CAN_TXBAR, 0x1); + + return NETDEV_TX_OK; +} + +static const struct net_device_ops m_can_netdev_ops = { + .ndo_open = m_can_open, + .ndo_stop = m_can_close, + .ndo_start_xmit = m_can_start_xmit, +}; + +static int register_m_can_dev(struct net_device *dev) +{ + dev->flags |= IFF_ECHO; /* we support local echo */ + dev->netdev_ops = &m_can_netdev_ops; + + return register_candev(dev); +} + +static int m_can_of_parse_mram(struct platform_device *pdev, + struct m_can_priv *priv) +{ + struct device_node *np = pdev->dev.of_node; + struct resource *res; + void __iomem *addr; + u32 out_val[MRAM_CFG_LEN]; + int ret; + + /* message ram could be shared */ + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram"); + if (!res) + return -ENODEV; + + addr = devm_ioremap(&pdev->dev, res->start, resource_size(res)); + if (!addr) + return -ENOMEM; + + /* get message ram configuration */ + ret = of_property_read_u32_array(np, "bosch,mram-cfg", + out_val, sizeof(out_val) / 4); + if (ret) { + dev_err(&pdev->dev, "can not get message ram configuration\n"); + return -ENODEV; + } + + priv->mram_base = addr; + priv->mcfg[MRAM_SIDF].off = out_val[0]; + priv->mcfg[MRAM_SIDF].num = out_val[1]; + priv->mcfg[MRAM_XIDF].off = priv->mcfg[MRAM_SIDF].off + + priv->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE; + priv->mcfg[MRAM_XIDF].num = out_val[2]; + priv->mcfg[MRAM_RXF0].off = priv->mcfg[MRAM_XIDF].off + + priv->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE; + priv->mcfg[MRAM_RXF0].num = out_val[3] & RXFC_FS_MASK; + priv->mcfg[MRAM_RXF1].off = priv->mcfg[MRAM_RXF0].off + + priv->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE; + priv->mcfg[MRAM_RXF1].num = out_val[4] & RXFC_FS_MASK; + priv->mcfg[MRAM_RXB].off = priv->mcfg[MRAM_RXF1].off + + priv->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE; + priv->mcfg[MRAM_RXB].num = out_val[5]; + priv->mcfg[MRAM_TXE].off = priv->mcfg[MRAM_RXB].off + + priv->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE; + priv->mcfg[MRAM_TXE].num = out_val[6]; + priv->mcfg[MRAM_TXB].off = priv->mcfg[MRAM_TXE].off + + priv->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE; + priv->mcfg[MRAM_TXB].num = out_val[7] & TXBC_NDTB_MASK; + + dev_dbg(&pdev->dev, "mram_base %p 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", + priv->mram_base, + priv->mcfg[MRAM_SIDF].off, priv->mcfg[MRAM_SIDF].num, + priv->mcfg[MRAM_XIDF].off, priv->mcfg[MRAM_XIDF].num, + priv->mcfg[MRAM_RXF0].off, priv->mcfg[MRAM_RXF0].num, + priv->mcfg[MRAM_RXF1].off, priv->mcfg[MRAM_RXF1].num, + priv->mcfg[MRAM_RXB].off, priv->mcfg[MRAM_RXB].num, + priv->mcfg[MRAM_TXE].off, priv->mcfg[MRAM_TXE].num, + priv->mcfg[MRAM_TXB].off, priv->mcfg[MRAM_TXB].num); + + return 0; +} + +static int m_can_plat_probe(struct platform_device *pdev) +{ + struct net_device *dev; + struct m_can_priv *priv; + struct resource *res; + void __iomem *addr; + struct clk *hclk, *cclk; + int irq, ret; + + hclk = devm_clk_get(&pdev->dev, "hclk"); + cclk = devm_clk_get(&pdev->dev, "cclk"); + if (IS_ERR(hclk) || IS_ERR(cclk)) { + dev_err(&pdev->dev, "no clock find\n"); + return -ENODEV; + } + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can"); + addr = devm_ioremap_resource(&pdev->dev, res); + irq = platform_get_irq_byname(pdev, "int0"); + if (IS_ERR(addr) || irq < 0) + return -EINVAL; + + /* allocate the m_can device */ + dev = alloc_m_can_dev(); + if (!dev) + return -ENOMEM; + + priv = netdev_priv(dev); + dev->irq = irq; + priv->base = addr; + priv->device = &pdev->dev; + priv->hclk = hclk; + priv->cclk = cclk; + priv->can.clock.freq = clk_get_rate(cclk); + + ret = m_can_of_parse_mram(pdev, priv); + if (ret) + goto failed_free_dev; + + platform_set_drvdata(pdev, dev); + SET_NETDEV_DEV(dev, &pdev->dev); + + ret = register_m_can_dev(dev); + if (ret) { + dev_err(&pdev->dev, "registering %s failed (err=%d)\n", + KBUILD_MODNAME, ret); + goto failed_free_dev; + } + + devm_can_led_init(dev); + + dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n", + KBUILD_MODNAME, priv->base, dev->irq); + + return 0; + +failed_free_dev: + free_m_can_dev(dev); + return ret; +} + +static __maybe_unused int m_can_suspend(struct device *dev) +{ + struct net_device *ndev = dev_get_drvdata(dev); + struct m_can_priv *priv = netdev_priv(ndev); + + if (netif_running(ndev)) { + netif_stop_queue(ndev); + netif_device_detach(ndev); + } + + /* TODO: enter low power */ + + priv->can.state = CAN_STATE_SLEEPING; + + return 0; +} + +static __maybe_unused int m_can_resume(struct device *dev) +{ + struct net_device *ndev = dev_get_drvdata(dev); + struct m_can_priv *priv = netdev_priv(ndev); + + /* TODO: exit low power */ + + priv->can.state = CAN_STATE_ERROR_ACTIVE; + + if (netif_running(ndev)) { + netif_device_attach(ndev); + netif_start_queue(ndev); + } + + return 0; +} + +static void unregister_m_can_dev(struct net_device *dev) +{ + unregister_candev(dev); +} + +static int m_can_plat_remove(struct platform_device *pdev) +{ + struct net_device *dev = platform_get_drvdata(pdev); + + unregister_m_can_dev(dev); + platform_set_drvdata(pdev, NULL); + + free_m_can_dev(dev); + + return 0; +} + +static const struct dev_pm_ops m_can_pmops = { + SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume) +}; + +static const struct of_device_id m_can_of_table[] = { + { .compatible = "bosch,m_can", .data = NULL }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, m_can_of_table); + +static struct platform_driver m_can_plat_driver = { + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = m_can_of_table, + .pm = &m_can_pmops, + }, + .probe = m_can_plat_probe, + .remove = m_can_plat_remove, +}; + +module_platform_driver(m_can_plat_driver); + +MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller"); |