// SPDX-License-Identifier: GPL-2.0-only /* * at91_can.c - CAN network driver for AT91 SoC CAN controller * * (C) 2007 by Hans J. Koch <[email protected]> * (C) 2008, 2009, 2010, 2011, 2023 by Marc Kleine-Budde <[email protected]> */ #include <linux/bitfield.h> #include <linux/clk.h> #include <linux/errno.h> #include <linux/ethtool.h> #include <linux/if_arp.h> #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/netdevice.h> #include <linux/of.h> #include <linux/phy/phy.h> #include <linux/platform_device.h> #include <linux/rtnetlink.h> #include <linux/skbuff.h> #include <linux/spinlock.h> #include <linux/string.h> #include <linux/types.h> #include <linux/can/dev.h> #include <linux/can/error.h> #include <linux/can/rx-offload.h> #define AT91_MB_MASK(i) … /* Common registers */ enum at91_reg { … }; /* Mailbox registers (0 <= i <= 15) */ #define AT91_MMR(i) … #define AT91_MAM(i) … #define AT91_MID(i) … #define AT91_MFID(i) … #define AT91_MSR(i) … #define AT91_MDL(i) … #define AT91_MDH(i) … #define AT91_MCR(i) … /* Register bits */ #define AT91_MR_CANEN … #define AT91_MR_LPM … #define AT91_MR_ABM … #define AT91_MR_OVL … #define AT91_MR_TEOF … #define AT91_MR_TTM … #define AT91_MR_TIMFRZ … #define AT91_MR_DRPT … #define AT91_SR_RBSY … #define AT91_SR_TBSY … #define AT91_SR_OVLSY … #define AT91_BR_PHASE2_MASK … #define AT91_BR_PHASE1_MASK … #define AT91_BR_PROPAG_MASK … #define AT91_BR_SJW_MASK … #define AT91_BR_BRP_MASK … #define AT91_BR_SMP … #define AT91_TIM_TIMER_MASK … #define AT91_ECR_REC_MASK … #define AT91_ECR_TEC_MASK … #define AT91_TCR_TIMRST … #define AT91_MMR_MTIMEMARK_MASK … #define AT91_MMR_PRIOR_MASK … #define AT91_MMR_MOT_MASK … #define AT91_MID_MIDVB_MASK … #define AT91_MID_MIDVA_MASK … #define AT91_MID_MIDE … #define AT91_MSR_MTIMESTAMP_MASK … #define AT91_MSR_MDLC_MASK … #define AT91_MSR_MRTR … #define AT91_MSR_MABT … #define AT91_MSR_MRDY … #define AT91_MSR_MMI … #define AT91_MCR_MDLC_MASK … #define AT91_MCR_MRTR … #define AT91_MCR_MACR … #define AT91_MCR_MTCR … /* Mailbox Modes */ enum at91_mb_mode { … }; /* Interrupt mask bits */ #define AT91_IRQ_ERRA … #define AT91_IRQ_WARN … #define AT91_IRQ_ERRP … #define AT91_IRQ_BOFF … #define AT91_IRQ_SLEEP … #define AT91_IRQ_WAKEUP … #define AT91_IRQ_TOVF … #define AT91_IRQ_TSTP … #define AT91_IRQ_CERR … #define AT91_IRQ_SERR … #define AT91_IRQ_AERR … #define AT91_IRQ_FERR … #define AT91_IRQ_BERR … #define AT91_IRQ_ERR_ALL … #define AT91_IRQ_ERR_FRAME … #define AT91_IRQ_ERR_LINE … #define AT91_IRQ_ALL … enum at91_devtype { … }; struct at91_devtype_data { … }; struct at91_priv { … }; static inline struct at91_priv *rx_offload_to_priv(struct can_rx_offload *offload) { … } static const struct at91_devtype_data at91_at91sam9263_data = …; static const struct at91_devtype_data at91_at91sam9x5_data = …; static const struct can_bittiming_const at91_bittiming_const = …; #define AT91_IS(_model) … AT91_IS(9263); AT91_IS(9X5); static inline unsigned int get_mb_rx_first(const struct at91_priv *priv) { … } static inline unsigned int get_mb_rx_last(const struct at91_priv *priv) { … } static inline unsigned int get_mb_tx_shift(const struct at91_priv *priv) { … } static inline unsigned int get_mb_tx_num(const struct at91_priv *priv) { … } static inline unsigned int get_mb_tx_first(const struct at91_priv *priv) { … } static inline unsigned int get_mb_tx_last(const struct at91_priv *priv) { … } static inline unsigned int get_head_prio_shift(const struct at91_priv *priv) { … } static inline unsigned int get_head_prio_mask(const struct at91_priv *priv) { … } static inline unsigned int get_head_mb_mask(const struct at91_priv *priv) { … } static inline unsigned int get_head_mask(const struct at91_priv *priv) { … } static inline unsigned int get_irq_mb_rx(const struct at91_priv *priv) { … } static inline unsigned int get_irq_mb_tx(const struct at91_priv *priv) { … } static inline unsigned int get_tx_head_mb(const struct at91_priv *priv) { … } static inline unsigned int get_tx_head_prio(const struct at91_priv *priv) { … } static inline unsigned int get_tx_tail_mb(const struct at91_priv *priv) { … } static inline u32 at91_read(const struct at91_priv *priv, enum at91_reg reg) { … } static inline void at91_write(const struct at91_priv *priv, enum at91_reg reg, u32 value) { … } static inline void set_mb_mode_prio(const struct at91_priv *priv, unsigned int mb, enum at91_mb_mode mode, u8 prio) { … } static inline void set_mb_mode(const struct at91_priv *priv, unsigned int mb, enum at91_mb_mode mode) { … } static inline u32 at91_can_id_to_reg_mid(canid_t can_id) { … } static void at91_setup_mailboxes(struct net_device *dev) { … } static int at91_set_bittiming(struct net_device *dev) { … } static int at91_get_berr_counter(const struct net_device *dev, struct can_berr_counter *bec) { … } static void at91_chip_start(struct net_device *dev) { … } static void at91_chip_stop(struct net_device *dev, enum can_state state) { … } /* theory of operation: * * According to the datasheet priority 0 is the highest priority, 15 * is the lowest. If two mailboxes have the same priority level the * message of the mailbox with the lowest number is sent first. * * We use the first TX mailbox (AT91_MB_TX_FIRST) with prio 0, then * the next mailbox with prio 0, and so on, until all mailboxes are * used. Then we start from the beginning with mailbox * AT91_MB_TX_FIRST, but with prio 1, mailbox AT91_MB_TX_FIRST + 1 * prio 1. When we reach the last mailbox with prio 15, we have to * stop sending, waiting for all messages to be delivered, then start * again with mailbox AT91_MB_TX_FIRST prio 0. * * We use the priv->tx_head as counter for the next transmission * mailbox, but without the offset AT91_MB_TX_FIRST. The lower bits * encode the mailbox number, the upper 4 bits the mailbox priority: * * priv->tx_head = (prio << get_next_prio_shift(priv)) | * (mb - get_mb_tx_first(priv)); * */ static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev) { … } static inline u32 at91_get_timestamp(const struct at91_priv *priv) { … } static inline struct sk_buff * at91_alloc_can_err_skb(struct net_device *dev, struct can_frame **cf, u32 *timestamp) { … } /** * at91_rx_overflow_err - send error frame due to rx overflow * @dev: net device */ static void at91_rx_overflow_err(struct net_device *dev) { … } /** * at91_mailbox_read - read CAN msg from mailbox * @offload: rx-offload * @mb: mailbox number to read from * @timestamp: pointer to 32 bit timestamp * @drop: true indicated mailbox to mark as read and drop frame * * Reads a CAN message from the given mailbox if not empty. */ static struct sk_buff *at91_mailbox_read(struct can_rx_offload *offload, unsigned int mb, u32 *timestamp, bool drop) { … } /* theory of operation: * * priv->tx_tail holds the number of the oldest can_frame put for * transmission into the hardware, but not yet ACKed by the CAN tx * complete IRQ. * * We iterate from priv->tx_tail to priv->tx_head and check if the * packet has been transmitted, echo it back to the CAN framework. If * we discover a not yet transmitted package, stop looking for more. * */ static void at91_irq_tx(struct net_device *dev, u32 reg_sr) { … } static void at91_irq_err_line(struct net_device *dev, const u32 reg_sr) { … } static void at91_irq_err_frame(struct net_device *dev, const u32 reg_sr) { … } static u32 at91_get_reg_sr_rx(const struct at91_priv *priv, u32 *reg_sr_p) { … } static irqreturn_t at91_irq(int irq, void *dev_id) { … } static int at91_open(struct net_device *dev) { … } /* stop CAN bus activity */ static int at91_close(struct net_device *dev) { … } static int at91_set_mode(struct net_device *dev, enum can_mode mode) { … } static const struct net_device_ops at91_netdev_ops = …; static const struct ethtool_ops at91_ethtool_ops = …; static ssize_t mb0_id_show(struct device *dev, struct device_attribute *attr, char *buf) { … } static ssize_t mb0_id_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { … } static DEVICE_ATTR_RW(mb0_id); static struct attribute *at91_sysfs_attrs[] = …; static const struct attribute_group at91_sysfs_attr_group = …; #if defined(CONFIG_OF) static const struct of_device_id at91_can_dt_ids[] = …; MODULE_DEVICE_TABLE(of, at91_can_dt_ids); #endif static const struct at91_devtype_data *at91_can_get_driver_data(struct platform_device *pdev) { … } static int at91_can_probe(struct platform_device *pdev) { … } static void at91_can_remove(struct platform_device *pdev) { … } static const struct platform_device_id at91_can_id_table[] = …; MODULE_DEVICE_TABLE(platform, at91_can_id_table); static struct platform_driver at91_can_driver = …; module_platform_driver(…) …; MODULE_AUTHOR(…) …; MODULE_LICENSE(…) …; MODULE_DESCRIPTION(…) …;
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