Re: [PATCH v3 4/7] can: Add Nuvoton NCT6694 CAN support
From: Vincent Mailhol <hidden>
Date: 2024-12-11 15:25:28
Also in:
linux-can, linux-gpio, linux-hwmon, linux-i2c, linux-rtc, linux-watchdog, lkml
On Wed. 11 Dec. 2024 at 18:59, Marc Kleine-Budde [off-list ref] wrote:
On 10.12.2024 18:45:21, Ming Yu wrote:quoted
This driver supports Socket CANfd functionality for NCT6694 MFD device based on USB interface.Please use the rx-offload helper, otherwise the CAN frames might be revived out of order.quoted
Signed-off-by: Ming Yu <tmyu0@nuvoton.com> --- MAINTAINERS | 1 + drivers/net/can/Kconfig | 10 + drivers/net/can/Makefile | 1 + drivers/net/can/nct6694_canfd.c | 920 ++++++++++++++++++++++++++++++++ 4 files changed, 932 insertions(+) create mode 100644 drivers/net/can/nct6694_canfd.cdiff --git a/MAINTAINERS b/MAINTAINERS index a190f2b08fa3..eb5d46825e71 100644 --- a/MAINTAINERS +++ b/MAINTAINERS@@ -16548,6 +16548,7 @@ S: Supported F: drivers/gpio/gpio-nct6694.c F: drivers/i2c/busses/i2c-nct6694.c F: drivers/mfd/nct6694.c +F: drivers/net/can/nct6694_canfd.c F: include/linux/mfd/nct6694.h NVIDIA (rivafb and nvidiafb) FRAMEBUFFER DRIVERdiff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig index cf989bea9aa3..130e98ec28a5 100644 --- a/drivers/net/can/Kconfig +++ b/drivers/net/can/Kconfig@@ -200,6 +200,16 @@ config CAN_SUN4I To compile this driver as a module, choose M here: the module will be called sun4i_can. +config CAN_NCT6694 + tristate "Nuvoton NCT6694 Socket CANfd support" + depends on MFD_NCT6694 + help + If you say yes to this option, support will be included for Nuvoton + NCT6694, a USB device to socket CANfd controller. + + This driver can also be built as a module. If so, the module will + be called nct6694_canfd. + config CAN_TI_HECC depends on ARM tristate "TI High End CAN Controller"diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile index a71db2cfe990..4a6b5b9d6c2b 100644 --- a/drivers/net/can/Makefile +++ b/drivers/net/can/Makefile@@ -28,6 +28,7 @@ obj-$(CONFIG_CAN_JANZ_ICAN3) += janz-ican3.o obj-$(CONFIG_CAN_KVASER_PCIEFD) += kvaser_pciefd.o obj-$(CONFIG_CAN_MSCAN) += mscan/ obj-$(CONFIG_CAN_M_CAN) += m_can/ +obj-$(CONFIG_CAN_NCT6694) += nct6694_canfd.o obj-$(CONFIG_CAN_PEAK_PCIEFD) += peak_canfd/ obj-$(CONFIG_CAN_SJA1000) += sja1000/ obj-$(CONFIG_CAN_SUN4I) += sun4i_can.odiff --git a/drivers/net/can/nct6694_canfd.c b/drivers/net/can/nct6694_canfd.c new file mode 100644 index 000000000000..54f20f0681e2 --- /dev/null +++ b/drivers/net/can/nct6694_canfd.c@@ -0,0 +1,920 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Nuvoton NCT6694 Socket CANfd driver based on USB interface. + * + * Copyright (C) 2024 Nuvoton Technology Corp. + */ + +#include <linux/can/dev.h> +#include <linux/ethtool.h> +#include <linux/irqdomain.h> +#include <linux/kernel.h> +#include <linux/mfd/core.h> +#include <linux/mfd/nct6694.h> +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/platform_device.h> + +#define DRVNAME "nct6694-can" + +/* Host interface */ +#define NCT6694_CAN_MOD 0x05 + +/* Message Channel*/ +/* Command 00h */
Instead of this comment, explain what the command 00h does. Also better to give a memorable name instead of CMD0. For example: CMD_TX, CMD_RX… If possible, make it match the structure names.
quoted
+#define NCT6694_CAN_CMD0_OFFSET(idx) (idx ? 0x0100 : 0x0000) +#define NCT6694_CAN_CTRL1_MON BIT(0) +#define NCT6694_CAN_CTRL1_NISO BIT(1) +#define NCT6694_CAN_CTRL1_LBCK BIT(2) + +/* Command 01h */ +#define NCT6694_CAN_CMD1_OFFSET 0x0001 + +/* Command 02h */ +#define NCT6694_CAN_CMD2_OFFSET(idx, mask) \ + ({ typeof(mask) mask_ = (mask); \ + idx ? ((0x80 | (mask_ & 0xFF)) << 8 | 0x02) : \ + ((0x00 | (mask_ & 0xFF)) << 8 | 0x02); }) + +#define NCT6694_CAN_EVENT_ERR BIT(0) +#define NCT6694_CAN_EVENT_STATUS BIT(1) +#define NCT6694_CAN_EVENT_TX_EVT BIT(2) +#define NCT6694_CAN_EVENT_RX_EVT BIT(3) +#define NCT6694_CAN_EVENT_REC BIT(4) +#define NCT6694_CAN_EVENT_TEC BIT(5) +#define NCT6694_CAN_EVT_TX_FIFO_EMPTY BIT(7) /* Read-clear */ +#define NCT6694_CAN_EVT_RX_DATA_LOST BIT(5) /* Read-clear */ +#define NCT6694_CAN_EVT_RX_HALF_FULL BIT(6) /* Read-clear */ +#define NCT6694_CAN_EVT_RX_DATA_IN BIT(7) + +/* Command 10h */ +#define NCT6694_CAN_CMD10_OFFSET(buf_cnt) \ + (((buf_cnt) & 0xFF) << 8 | 0x10) +#define NCT6694_CAN_TAG_CAN0 0xC0 +#define NCT6694_CAN_TAG_CAN1 0xC1 +#define NCT6694_CAN_FLAG_EFF BIT(0) +#define NCT6694_CAN_FLAG_RTR BIT(1) +#define NCT6694_CAN_FLAG_FD BIT(2) +#define NCT6694_CAN_FLAG_BRS BIT(3) +#define NCT6694_CAN_FLAG_ERR BIT(4) + +/* Command 11h */ +#define NCT6694_CAN_CMD11_OFFSET(idx, buf_cnt) \ + ({ typeof(buf_cnt) buf_cnt_ = (buf_cnt); \ + idx ? ((0x80 | (buf_cnt_ & 0xFF)) << 8 | 0x11) : \ + ((0x00 | (buf_cnt_ & 0xFF)) << 8 | 0x11); })
Simplify this. Do something like:
#define NCT6694_CAN_CMD11_OFFSET(idx, buf_cnt) \
(idx ? 0x80 : 0x00) | \
(buf_cnt & 0xFF)) << 8 | 0x11) \
(apply this also to NCT6694_CAN_CMD2_OFFSET())
quoted
+#define NCT6694_CAN_RX_QUOTA 64 + +enum nct6694_event_err { + NCT6694_CAN_EVT_NO_ERROR,^^^ add _ERR_quoted
+ NCT6694_CAN_EVT_CRC_ERROR, + NCT6694_CAN_EVT_STUFF_ERROR, + NCT6694_CAN_EVT_ACK_ERROR, + NCT6694_CAN_EVT_FORM_ERROR, + NCT6694_CAN_EVT_BIT_ERROR, + NCT6694_CAN_EVT_TIMEOUT_ERROR, + NCT6694_CAN_EVT_UNKNOWN_ERROR, +}; + +enum nct6694_event_status { + NCT6694_CAN_EVT_ERROR_ACTIVE,^^^ add _STATUS_quoted
+ NCT6694_CAN_EVT_ERROR_PASSIVE, + NCT6694_CAN_EVT_BUS_OFF, + NCT6694_CAN_EVT_WARNING, +}; + +struct __packed nct6694_can_setting { + __le32 nbr; + __le32 dbr; + u8 active; + u8 reserved[3]; + __le16 ctrl1; + __le16 ctrl2; + __le32 nbtp; + __le32 dbtp; +}; + +struct __packed nct6694_can_information { + u8 tx_fifo_cnt; + u8 rx_fifo_cnt; + __le16 reserved;u8 reserved[2];quoted
+ __le32 can_clk; +}; + +struct __packed nct6694_can_event { + u8 err1; + u8 status1; + u8 tx_evt1; + u8 rx_evt1; + u8 rec1; + u8 tec1; + u8 reserved1[2]; + u8 err2; + u8 status2; + u8 tx_evt2; + u8 rx_evt2; + u8 rec2; + u8 tec2; + u8 reserved2[2]; +};Create an extra struct that only describes a channel struct __packed nct6694_can_event_channel { u8 err; u8 status; u8 tx_evt; u8 rx_evt; u8 rec; u8 tec; u8 reserved[2]; } and put an array of 2 into struct __packed nct6694_can_event.quoted
+ +struct __packed nct6694_can_xmit {
Is this struct for both TX and RX? If so, name it something like struct nct6694_can_frame The term xmit is only used for transmission, not for reception.
quoted
+ u8 tag; + u8 flag; + u8 reserved; + u8 dlc; + __le32 id; + u8 data[64]; + u8 msg_buf[72];Why is the message so long? What's in the msg_buf?quoted
+}; + +struct nct6694_can_priv { + struct can_priv can; /* must be the first member */ + struct net_device *ndev; + struct nct6694 *nct6694; + struct mutex lock;What does lock protect?
+1
mutexes are good if you want to keep the lock for a long time.
For short period, spinlock are more performant:
spinlock_t lock;
quoted
+ struct sk_buff *tx_skb; + struct workqueue_struct *wq; + struct work_struct tx_work; + unsigned char *tx_buf;void *quoted
+ unsigned char *rx_buf;void *
Rather than void*, tx_buf and rx_buf can be replaced by an union:
union nct6694_can_rx {
struct nct6694_can_event event;
struct nct6694_can_xmit xmit;
struct nct6694_can_information info;
};
(same for nct6694_can_tx)
Then in struct nct6694_can_priv, you will just have:
union nct6694_can_tx tx;
union nct6694_can_rx rx;
With this,
NCT6694_MAX_PACKET_SZ
can most likely be replaced by sizeof(union nct6694_can_rx) or
sizeof(union nct6694_can_tx).
quoted
+ unsigned char can_idx; + bool tx_busy;IMHO it makes no sense to have tx_skb and tx_busyquoted
+}; + +static const struct can_bittiming_const nct6694_can_bittiming_nominal_const = { + .name = DRVNAME, + .tseg1_min = 2, + .tseg1_max = 256, + .tseg2_min = 2, + .tseg2_max = 128, + .sjw_max = 128, + .brp_min = 1, + .brp_max = 511, + .brp_inc = 1, +}; + +static const struct can_bittiming_const nct6694_can_bittiming_data_const = { + .name = DRVNAME, + .tseg1_min = 1, + .tseg1_max = 32, + .tseg2_min = 1, + .tseg2_max = 16, + .sjw_max = 16, + .brp_min = 1, + .brp_max = 31, + .brp_inc = 1, +}; + +static void nct6694_can_clean(struct net_device *ndev) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + + if (priv->tx_skb || priv->tx_busy) + ndev->stats.tx_errors++; + dev_kfree_skb(priv->tx_skb); + if (priv->tx_busy) + can_free_echo_skb(priv->ndev, 0, NULL); + priv->tx_skb = NULL; + priv->tx_busy = false; +} + +static int nct6694_can_get_berr_counter(const struct net_device *ndev, + struct can_berr_counter *bec) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + struct nct6694_can_event *evt = (struct nct6694_can_event *)priv->rx_buf; + u8 mask = NCT6694_CAN_EVENT_REC | NCT6694_CAN_EVENT_TEC; + int ret; + + guard(mutex)(&priv->lock); + + ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD, + NCT6694_CAN_CMD2_OFFSET(priv->can_idx, mask), + sizeof(struct nct6694_can_event), + evt); + if (ret < 0) + return ret; + + bec->rxerr = priv->can_idx ? evt->rec2 : evt->rec1; + bec->txerr = priv->can_idx ? evt->tec2 : evt->tec1; + + return 0; +} + +static int nct6694_can_handle_lost_msg(struct net_device *ndev) +{ + struct net_device_stats *stats = &ndev->stats; + struct sk_buff *skb; + struct can_frame *frame; + + netdev_err(ndev, "RX FIFO overflow, message(s) lost.\n"); + + stats->rx_errors++; + stats->rx_over_errors++; + + skb = alloc_can_err_skb(ndev, &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 void nct6694_can_read_fifo(struct net_device *ndev) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + struct nct6694_can_xmit *xmit = (struct nct6694_can_xmit *)priv->rx_buf; + struct net_device_stats *stats = &ndev->stats; + struct canfd_frame *cf; + struct sk_buff *skb; + int can_idx = priv->can_idx; + u32 id; + int ret; + u8 fd_format = 0;bool - no need to initquoted
+ + guard(mutex)(&priv->lock); + + ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD, + NCT6694_CAN_CMD11_OFFSET(can_idx, 1), + sizeof(struct nct6694_can_xmit), xmit); + if (ret < 0) + return; + + /* Check type of frame and create skb */ + fd_format = xmit->flag & NCT6694_CAN_FLAG_FD; + if (fd_format) + skb = alloc_canfd_skb(ndev, &cf); + else + skb = alloc_can_skb(ndev, (struct can_frame **)&cf); + + if (!skb) { + stats->rx_dropped++; + return; + } + + cf->len = xmit->dlc;what does xmit->dlc contain? The DLC or the length?
+1 Also, do not trust the device data. Even if SPI attacks are less common, make sure to sanitize this length. cf->len = canfd_sanitize_len(xmit->dlc); Or cf->len = canfd_sanitize_len(xmit->dlc); if xmit->dlc is in fact a DLC.
quoted
+ + /* Get ID and set flag by its type(Standard ID format or Ext ID format) */ + id = le32_to_cpu(xmit->id); + if (xmit->flag & NCT6694_CAN_FLAG_EFF) { + /* + * In case the Extended ID frame is received, the standard + * and extended part of the ID are swapped in the register, + * so swap them back to obtain the correct ID. + */You comment doesn't match the code.quoted
+ id |= CAN_EFF_FLAG; + } + + cf->can_id = id; + + /* Set ESI flag */ + if (xmit->flag & NCT6694_CAN_FLAG_ERR) { + cf->flags |= CANFD_ESI; + netdev_dbg(ndev, "ESI Error\n"); + } + + /* Set RTR and BRS */ + if (!fd_format && (xmit->flag & NCT6694_CAN_FLAG_RTR)) { + cf->can_id |= CAN_RTR_FLAG; + } else { + if (xmit->flag & NCT6694_CAN_FLAG_BRS) + cf->flags |= CANFD_BRS; + + memcpy(cf->data, xmit->data, cf->len); + + stats->rx_bytes += cf->len; + } + + stats->rx_packets++; + + netif_receive_skb(skb); +} + +static int nct6694_can_do_rx_poll(struct net_device *ndev, int quota) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + struct nct6694_can_event *evt = (struct nct6694_can_event *)priv->rx_buf; + int can_idx = priv->can_idx; + u32 pkts = 0; + u8 mask_rx = NCT6694_CAN_EVENT_RX_EVT; + u8 rx_evt; + + for (;;) { + scoped_guard(mutex, &priv->lock) { + nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD, + NCT6694_CAN_CMD2_OFFSET(can_idx, mask_rx), + sizeof(struct nct6694_can_event), evt); + + rx_evt = can_idx ? evt->rx_evt2 : evt->rx_evt1; + } + + if (rx_evt & NCT6694_CAN_EVT_RX_DATA_LOST) + nct6694_can_handle_lost_msg(ndev); + + /* No data */ + if ((rx_evt & NCT6694_CAN_EVT_RX_DATA_IN) == 0) + break; + + if (quota <= 0) + break; + + nct6694_can_read_fifo(ndev); + quota--; + pkts++; + } + + return pkts; +} + +static int nct6694_can_handle_lec_err(struct net_device *ndev, u8 bus_err) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + struct net_device_stats *stats = &ndev->stats; + struct can_frame *cf; + struct sk_buff *skb; + + if (bus_err == NCT6694_CAN_EVT_NO_ERROR) + return 0; + + priv->can.can_stats.bus_error++; + stats->rx_errors++; + + /* Propagate the error condition to the CAN stack. */ + skb = alloc_can_err_skb(ndev, &cf); + + if (unlikely(!skb)) + return 0;
Do not exit if the memory allocation fails. Instead, do the error handling to increase the statistics. Look at what other CAN drivers are doing.
quoted
+ /* Read the error counter register and check for new errors. */ + cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; + + switch (bus_err) { + case NCT6694_CAN_EVT_CRC_ERROR: + cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; + break; + + case NCT6694_CAN_EVT_STUFF_ERROR: + cf->data[2] |= CAN_ERR_PROT_STUFF; + break; + + case NCT6694_CAN_EVT_ACK_ERROR: + cf->data[3] = CAN_ERR_PROT_LOC_ACK; + break; + + case NCT6694_CAN_EVT_FORM_ERROR: + cf->data[2] |= CAN_ERR_PROT_FORM; + break; + + case NCT6694_CAN_EVT_BIT_ERROR: + cf->data[2] |= CAN_ERR_PROT_BIT | + CAN_ERR_PROT_BIT0 | + CAN_ERR_PROT_BIT1; + break; + + case NCT6694_CAN_EVT_TIMEOUT_ERROR: + cf->data[2] |= CAN_ERR_PROT_UNSPEC; + break; + + case NCT6694_CAN_EVT_UNKNOWN_ERROR: + cf->data[2] |= CAN_ERR_PROT_UNSPEC; + /* + * It means 'unspecified'(the value is '0'). + * But it is not sure if it's ok to send an error package + * without specific error bit. + */ + break; + + default: + break; + } + + /* Reset the error counter, ack the IRQ and re-enable the counter. */ + stats->rx_packets++; + stats->rx_bytes += cf->can_dlc;
The CAN error frames are not regular packets. Do not increase the RX stats. Instead, increase the error stats.
quoted
+ netif_receive_skb(skb); + + return 1; +} + +static int nct6694_can_handle_state_change(struct net_device *ndev, + enum can_state new_state) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + struct net_device_stats *stats = &ndev->stats; + struct can_frame *cf; + struct sk_buff *skb; + struct can_berr_counter bec; + + switch (new_state) { + case CAN_STATE_ERROR_ACTIVE: + priv->can.can_stats.error_warning++; + priv->can.state = CAN_STATE_ERROR_ACTIVE; + break; + case CAN_STATE_ERROR_WARNING: + priv->can.can_stats.error_warning++; + priv->can.state = CAN_STATE_ERROR_WARNING; + break; + case CAN_STATE_ERROR_PASSIVE: + priv->can.can_stats.error_passive++; + priv->can.state = CAN_STATE_ERROR_PASSIVE; + break; + case CAN_STATE_BUS_OFF: + priv->can.state = CAN_STATE_BUS_OFF; + priv->can.can_stats.bus_off++; + can_bus_off(ndev); + break; + default: + break; + } + + /* propagate the error condition to the CAN stack */ + skb = alloc_can_err_skb(ndev, &cf); + if (unlikely(!skb)) + return 0;
Same as above: handle the statistics even if the allocation fails.
quoted
+ nct6694_can_get_berr_counter(ndev, &bec); + + switch (new_state) { + case CAN_STATE_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;
Prefer an if/else here instead of the ternary operator. It is more readable.
quoted
+ 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; + 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;
Do not increase the RX stats when you receive a CAN event.
quoted
+ netif_receive_skb(skb); + + return 1; +} + +static int nct6694_can_handle_state_errors(struct net_device *ndev, + unsigned char can_status) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + int work_done = 0; + + if (can_status == NCT6694_CAN_EVT_ERROR_ACTIVE && + priv->can.state != CAN_STATE_ERROR_ACTIVE) { + netdev_dbg(ndev, "Error, entered active state\n"); + work_done += nct6694_can_handle_state_change(ndev, + CAN_STATE_ERROR_ACTIVE); + } + + if (can_status == NCT6694_CAN_EVT_WARNING && + priv->can.state != CAN_STATE_ERROR_WARNING) { + netdev_dbg(ndev, "Error, entered warning state\n"); + work_done += nct6694_can_handle_state_change(ndev, + CAN_STATE_ERROR_WARNING); + } + + if (can_status == NCT6694_CAN_EVT_ERROR_PASSIVE && + priv->can.state != CAN_STATE_ERROR_PASSIVE) { + netdev_dbg(ndev, "Error, entered passive state\n"); + work_done += nct6694_can_handle_state_change(ndev, + CAN_STATE_ERROR_PASSIVE); + } + + if (can_status == NCT6694_CAN_EVT_BUS_OFF && + priv->can.state != CAN_STATE_BUS_OFF) { + netdev_dbg(ndev, "Error, entered bus-off state\n"); + work_done += nct6694_can_handle_state_change(ndev, + CAN_STATE_BUS_OFF); + } + + return work_done; +} + +static int nct6694_can_poll(struct net_device *ndev, int quota) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + struct nct6694_can_event *evt = (struct nct6694_can_event *)priv->rx_buf; + int can_idx = priv->can_idx; + int work_done = 0, ret; + u8 evt_mask = NCT6694_CAN_EVENT_ERR | NCT6694_CAN_EVENT_STATUS; + u8 bus_err, can_status; + + scoped_guard(mutex, &priv->lock) { + ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD, + NCT6694_CAN_CMD2_OFFSET(can_idx, evt_mask), + sizeof(struct nct6694_can_event), evt); + if (ret < 0) + return IRQ_NONE;propagate the errorquoted
+ + if (can_idx) { + bus_err = evt->err2; + can_status = evt->status2; + } else { + bus_err = evt->err1; + can_status = evt->status1; + } + } + + /* Handle bus state changes */ + work_done += nct6694_can_handle_state_errors(ndev, can_status); + + /* Handle lec errors on the bus */ + if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) + work_done += nct6694_can_handle_lec_err(ndev, bus_err); + + /* Handle RX events */ + work_done += nct6694_can_do_rx_poll(ndev, quota - work_done); + return work_done; +} + +static void nct6694_can_tx_irq(struct net_device *ndev) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + struct net_device_stats *stats = &ndev->stats; + + guard(mutex)(&priv->lock); + stats->tx_bytes += can_get_echo_skb(ndev, 0, NULL); + stats->tx_packets++; + priv->tx_busy = false; + netif_wake_queue(ndev); +} + +static irqreturn_t nct6694_can_irq(int irq, void *data) +{ + struct net_device *ndev = data; + struct nct6694_can_priv *priv = netdev_priv(ndev); + struct nct6694_can_event *evt = (struct nct6694_can_event *)priv->rx_buf; + int can_idx = priv->can_idx; + int ret; + u8 mask_sts = NCT6694_CAN_EVENT_TX_EVT; + u8 tx_evt; + + scoped_guard(mutex, &priv->lock) { + ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD, + NCT6694_CAN_CMD2_OFFSET(can_idx, mask_sts), + sizeof(struct nct6694_can_event), evt); + if (ret < 0) + return IRQ_NONE; + + tx_evt = can_idx ? evt->tx_evt2 : evt->tx_evt1; + } + + if (tx_evt) { + nct6694_can_tx_irq(ndev); + } else { + ret = nct6694_can_poll(ndev, NCT6694_CAN_RX_QUOTA); + if (!ret) + return IRQ_NONE; + } + + return IRQ_HANDLED; +} + +static int nct6694_can_start(struct net_device *ndev) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + struct nct6694_can_setting *setting = (struct nct6694_can_setting *)priv->tx_buf; + const struct can_bittiming *n_bt = &priv->can.bittiming; + const struct can_bittiming *d_bt = &priv->can.data_bittiming; + int ret; + + guard(mutex)(&priv->lock); + + memset(priv->tx_buf, 0, sizeof(struct nct6694_can_setting));
When you memset(), use this pattern:
memset(setting, 0, sizeof(*setting));
Apply this throughout your driver.
quoted
+ setting->nbr = cpu_to_le32(n_bt->bitrate); + setting->dbr = cpu_to_le32(d_bt->bitrate); + + if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) + setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_CTRL1_MON); + + if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) && + priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO) + setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_CTRL1_NISO); + + if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) + setting->ctrl1 |= cpu_to_le16(NCT6694_CAN_CTRL1_LBCK); + + ret = nct6694_write_msg(priv->nct6694, NCT6694_CAN_MOD, + NCT6694_CAN_CMD0_OFFSET(priv->can_idx), + sizeof(struct nct6694_can_setting), setting); + if (ret < 0) + return ret; + + priv->can.state = CAN_STATE_ERROR_ACTIVE; + + return 0; +} + +static int nct6694_can_stop(struct net_device *ndev) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + + netif_stop_queue(ndev); + free_irq(ndev->irq, ndev); + destroy_workqueue(priv->wq); + priv->wq = NULL; + nct6694_can_clean(ndev); + priv->can.state = CAN_STATE_STOPPED; + close_candev(ndev); + + return 0; +} + +static int nct6694_can_set_mode(struct net_device *ndev, enum can_mode mode) +{ + switch (mode) { + case CAN_MODE_START: + nct6694_can_clean(ndev); + nct6694_can_start(ndev); + netif_wake_queue(ndev); + break; + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static int nct6694_can_open(struct net_device *ndev) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + int ret; + + ret = open_candev(ndev); + if (ret) + return ret; + + ret = request_threaded_irq(ndev->irq, NULL, + nct6694_can_irq, IRQF_ONESHOT, + "nct6694_can", ndev); + if (ret) { + netdev_err(ndev, "Failed to request IRQ\n"); + goto close_candev; + } + + priv->wq = alloc_ordered_workqueue("%s-nct6694_wq", + WQ_FREEZABLE | WQ_MEM_RECLAIM, + ndev->name); + if (!priv->wq) { + ret = -ENOMEM; + goto free_irq; + } + + priv->tx_skb = NULL; + priv->tx_busy = false; + + ret = nct6694_can_start(ndev); + if (ret) + goto destroy_wq; + + netif_start_queue(ndev); + + return 0; + +destroy_wq: + destroy_workqueue(priv->wq); +free_irq: + free_irq(ndev->irq, ndev); +close_candev: + close_candev(ndev); + return ret; +} + +static netdev_tx_t nct6694_can_start_xmit(struct sk_buff *skb, + struct net_device *ndev) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + + if (priv->tx_skb || priv->tx_busy) { + netdev_err(ndev, "hard_xmit called while tx busy\n"); + return NETDEV_TX_BUSY; + } + + if (can_dev_dropped_skb(ndev, skb)) + return NETDEV_TX_OK;please drop firstquoted
+ + netif_stop_queue(ndev); + priv->tx_skb = skb; + queue_work(priv->wq, &priv->tx_work); + + return NETDEV_TX_OK; +} + +static void nct6694_can_tx(struct net_device *ndev, struct canfd_frame *cf) +{ + struct nct6694_can_priv *priv = netdev_priv(ndev); + struct nct6694_can_xmit *xmit = (struct nct6694_can_xmit *)priv->tx_buf; + u32 txid = 0; + + memset(xmit, 0, sizeof(struct nct6694_can_xmit)); + + if (priv->can_idx == 0) + xmit->tag = NCT6694_CAN_TAG_CAN0<; + else + xmit->tag = NCT6694_CAN_TAG_CAN1; + + if (cf->can_id & CAN_EFF_FLAG) { + txid = cf->can_id & CAN_EFF_MASK; + /* + * In case the Extended ID frame is transmitted, the + * standard and extended part of the ID are swapped + * in the register, so swap them back to send the + * correct ID.You comment doesn't match the code.quoted
+ */ + xmit->flag |= NCT6694_CAN_FLAG_EFF; + } else { + txid = cf->can_id & CAN_SFF_MASK; + } + + xmit->id = cpu_to_le32(txid); + xmit->dlc = cf->len; + + if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) &&No need to check ctrlmodequoted
+ can_is_canfd_skb(priv->tx_skb)) { + xmit->flag |= NCT6694_CAN_FLAG_FD; + if (cf->flags & CANFD_BRS) + xmit->flag |= NCT6694_CAN_FLAG_BRS; + } + + if (cf->can_id & CAN_RTR_FLAG) + xmit->flag |= NCT6694_CAN_FLAG_RTR;you can move this into the !can_is_canfd_skb branch of the ifquoted
+ + memcpy(xmit->data, cf->data, cf->len); + + nct6694_write_msg(priv->nct6694, NCT6694_CAN_MOD, + NCT6694_CAN_CMD10_OFFSET(1), + sizeof(struct nct6694_can_xmit), + xmit); +} + +static void nct6694_can_tx_work(struct work_struct *work) +{ + struct nct6694_can_priv *priv = container_of(work, + struct nct6694_can_priv, + tx_work); + struct net_device *ndev = priv->ndev; + struct canfd_frame *cf; + + guard(mutex)(&priv->lock); + + if (priv->tx_skb) { + if (priv->can.state == CAN_STATE_BUS_OFF) { + nct6694_can_clean(ndev); + } else { + cf = (struct canfd_frame *)priv->tx_skb->data; + nct6694_can_tx(ndev, cf); + priv->tx_busy = true; + can_put_echo_skb(priv->tx_skb, ndev, 0, 0); + priv->tx_skb = NULL; + } + } +} + +static const struct net_device_ops nct6694_can_netdev_ops = { + .ndo_open = nct6694_can_open, + .ndo_stop = nct6694_can_stop, + .ndo_start_xmit = nct6694_can_start_xmit, + .ndo_change_mtu = can_change_mtu, +}; + +static const struct ethtool_ops nct6694_can_ethtool_ops = { + .get_ts_info = ethtool_op_get_ts_info, +}; + +static int nct6694_can_get_clock(struct nct6694_can_priv *priv) +{ + struct nct6694_can_information *info = (struct nct6694_can_information *)priv->rx_buf; + int ret; + + ret = nct6694_read_msg(priv->nct6694, NCT6694_CAN_MOD, + NCT6694_CAN_CMD1_OFFSET, + sizeof(struct nct6694_can_information), + info); + if (ret) + return ret; + + return le32_to_cpu(info->can_clk); +} + +static int nct6694_can_probe(struct platform_device *pdev) +{ + const struct mfd_cell *cell = mfd_get_cell(pdev); + struct nct6694 *nct6694 = dev_get_drvdata(pdev->dev.parent); + struct nct6694_can_priv *priv; + struct net_device *ndev; + int ret, irq, can_clk; + + irq = irq_create_mapping(nct6694->domain, + NCT6694_IRQ_CAN1 + cell->id); + if (!irq) + return -EINVAL;propagate error valuequoted
+ + ndev = alloc_candev(sizeof(struct nct6694_can_priv), 1); + if (!ndev) + return -ENOMEM; + + ndev->irq = irq; + ndev->flags |= IFF_ECHO; + ndev->netdev_ops = &nct6694_can_netdev_ops; + ndev->ethtool_ops = &nct6694_can_ethtool_ops; + + priv = netdev_priv(ndev); + priv->nct6694 = nct6694; + priv->ndev = ndev; + + priv->tx_buf = devm_kcalloc(&pdev->dev, NCT6694_MAX_PACKET_SZ, + sizeof(unsigned char), GFP_KERNEL);devm_kzalloc()quoted
+ if (!priv->tx_buf) { + ret = -ENOMEM; + goto free_candev; + } + + priv->rx_buf = devm_kcalloc(&pdev->dev, NCT6694_MAX_PACKET_SZ, + sizeof(unsigned char), GFP_KERNEL);devm_kzalloc()quoted
+ if (!priv->rx_buf) { + ret = -ENOMEM; + goto free_candev; + } + + can_clk = nct6694_can_get_clock(priv); + if (can_clk < 0) { + ret = -EIO;propagate the error value, don't overwrite it move the dev_err_probe() here.quoted
+ goto free_candev; + } + + mutex_init(&priv->lock); + INIT_WORK(&priv->tx_work, nct6694_can_tx_work); + + priv->can_idx = cell->id; + priv->can.state = CAN_STATE_STOPPED; + priv->can.clock.freq = can_clk; + priv->can.bittiming_const = &nct6694_can_bittiming_nominal_const; + priv->can.data_bittiming_const = &nct6694_can_bittiming_data_const; + priv->can.do_set_mode = nct6694_can_set_mode; + priv->can.do_get_berr_counter = nct6694_can_get_berr_counter; + + priv->can.ctrlmode = CAN_CTRLMODE_FD; + + priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | + CAN_CTRLMODE_LISTENONLY | + CAN_CTRLMODE_FD | + CAN_CTRLMODE_FD_NON_ISO | + CAN_CTRLMODE_BERR_REPORTING; + + platform_set_drvdata(pdev, priv); + SET_NETDEV_DEV(priv->ndev, &pdev->dev); + + ret = register_candev(priv->ndev); + if (ret) + goto free_candev; + + return 0; + +free_candev: + free_candev(ndev); + return dev_err_probe(&pdev->dev, ret, "Probe failed\n");Move the dev_err_probe() with an appropriate error message to where the error occurs. If malloc fails, the kernel already prints for you, so here it's only nct6694_can_get_clock() only.quoted
+} + +static void nct6694_can_remove(struct platform_device *pdev) +{ + struct nct6694_can_priv *priv = platform_get_drvdata(pdev); + + cancel_work_sync(&priv->tx_work); + unregister_candev(priv->ndev); + free_candev(priv->ndev); +} + +static struct platform_driver nct6694_can_driver = { + .driver = { + .name = DRVNAME, + }, + .probe = nct6694_can_probe, + .remove = nct6694_can_remove, +}; + +module_platform_driver(nct6694_can_driver); + +MODULE_DESCRIPTION("USB-CAN FD driver for NCT6694"); +MODULE_AUTHOR("Ming Yu [off-list ref]"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:nct6694-can");
Yours sincerely, Vincent Mailhol