Merge tag 'linux-can-next-for-5.11-20201120' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2020-11-20

The first patch is by Yegor Yefremov and he improves the j1939 documentaton by
adding tables for the CAN identifier and its fields.

Then there are 8 patches by Oliver Hartkopp targeting the CAN driver
infrastructure and drivers. These add support for optional DLC element to the
Classical CAN frame structure. See patch ea7800565a12 ("can: add optional DLC
element to Classical CAN frame structure") for details. Oliver's last patch
adds len8_dlc support to several drivers. Stefan Mätje provides a patch to add
len8_dlc support to the esd_usb2 driver.

The next patch is by Oliver Hartkopp, too and adds support for modification of
Classical CAN DLCs to CAN GW sockets.

The next 3 patches target the nxp,flexcan DT bindings. One patch by my adds the
missing uint32 reference to the clock-frequency property. Joakim Zhang's
patches fix the fsl,clk-source property and add the IMX_SC_R_CAN() macro to the
imx firmware header file, which will be used in the flexcan driver later.

Another patch by Joakim Zhang prepares the flexcan driver for SCU based
stop-mode, by giving the existing, GPR based stop-mode, a _GPR postfix.

The next 5 patches are by me, target the flexcan driver, and clean up the
.ndo_open and .ndo_stop callbacks. These patches try to fix a sporadically
hanging flexcan_close() during simultanious ifdown, sending of CAN messages and
probably open CAN bus. I was never able to reproduce, but these seem to fix the
problem at the reporting user. As these changes are rather big, I'd like to
mainline them via net-next/master.

The next patches are by Jimmy Assarsson and Christer Beskow, they add support
for new USB devices to the existing kvaser_usb driver.

The last patch is by Kaixu Xia and simplifies the return in the
mcp251xfd_chip_softreset() function in the mcp251xfd driver.

* tag 'linux-can-next-for-5.11-20201120' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next: (25 commits)
  can: mcp251xfd: remove useless code in mcp251xfd_chip_softreset
  can: kvaser_usb: Add new Kvaser hydra devices
  can: kvaser_usb: kvaser_usb_hydra: Add support for new device variant
  can: kvaser_usb: Add new Kvaser Leaf v2 devices
  can: kvaser_usb: Add USB_{LEAF,HYDRA}_PRODUCT_ID_END defines
  can: flexcan: flexcan_close(): change order if commands to properly shut down the controller
  can: flexcan: flexcan_open(): completely initialize controller before requesting IRQ
  can: flexcan: flexcan_rx_offload_setup(): factor out mailbox and rx-offload setup into separate function
  can: flexcan: move enabling/disabling of interrupts from flexcan_chip_{start,stop}() to callers
  can: flexcan: factor out enabling and disabling of interrupts into separate function
  can: flexcan: rename macro FLEXCAN_QUIRK_SETUP_STOP_MODE -> FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR
  dt-bindings: firmware: add IMX_SC_R_CAN(x) macro for CAN
  dt-bindings: can: fsl,flexcan: fix fsl,clk-source property
  dt-bindings: can: fsl,flexcan: add uint32 reference to clock-frequency property
  can: gw: support modification of Classical CAN DLCs
  can: drivers: add len8_dlc support for esd_usb2 CAN adapter
  can: drivers: add len8_dlc support for various CAN adapters
  can: drivers: introduce helpers to access Classical CAN DLC values
  can: update documentation for DLC usage in Classical CAN
  can: rename CAN FD related can_len2dlc and can_dlc2len helpers
  ...
====================

Link: https://lore.kernel.org/r/20201120133318.3428231-1-mkl@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 31 insertions, 7 deletions

diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 41ff31795320..197a79535cc2 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -98,14 +98,13 @@ static inline unsigned int can_bit_time(const struct can_bittiming *bt)
 }
 
 /*
- * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
- * to u8 and ensure the dlc value to be max. 8 bytes.
+ * can_cc_dlc2len(value) - convert a given data length code (dlc) of a
+ * Classical CAN frame into a valid data length of max. 8 bytes.
  *
  * To be used in the CAN netdriver receive path to ensure conformance with
  * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
  */
-#define get_can_dlc(i)		(min_t(u8, (i), CAN_MAX_DLC))
-#define get_canfd_dlc(i)	(min_t(u8, (i), CANFD_MAX_DLC))
+#define can_cc_dlc2len(dlc)	(min_t(u8, (dlc), CAN_MAX_DLEN))
 
 /* Check for outgoing skbs that have not been created by the CAN subsystem */
 static inline bool can_skb_headroom_valid(struct net_device *dev,
@@ -171,6 +170,31 @@ static inline bool can_is_canfd_skb(const struct sk_buff *skb)
 	return skb->len == CANFD_MTU;
 }
 
+/* helper to get the data length code (DLC) for Classical CAN raw DLC access */
+static inline u8 can_get_cc_dlc(const struct can_frame *cf, const u32 ctrlmode)
+{
+	/* return len8_dlc as dlc value only if all conditions apply */
+	if ((ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC) &&
+	    (cf->len == CAN_MAX_DLEN) &&
+	    (cf->len8_dlc > CAN_MAX_DLEN && cf->len8_dlc <= CAN_MAX_RAW_DLC))
+		return cf->len8_dlc;
+
+	/* return the payload length as dlc value */
+	return cf->len;
+}
+
+/* helper to set len and len8_dlc value for Classical CAN raw DLC access */
+static inline void can_frame_set_cc_len(struct can_frame *cf, const u8 dlc,
+					const u32 ctrlmode)
+{
+	/* the caller already ensured that dlc is a value from 0 .. 15 */
+	if (ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC && dlc > CAN_MAX_DLEN)
+		cf->len8_dlc = dlc;
+
+	/* limit the payload length 'len' to CAN_MAX_DLEN */
+	cf->len = can_cc_dlc2len(dlc);
+}
+
 /* helper to define static CAN controller features at device creation time */
 static inline void can_set_static_ctrlmode(struct net_device *dev,
 					   u32 static_mode)
@@ -186,11 +210,11 @@ static inline void can_set_static_ctrlmode(struct net_device *dev,
 		dev->mtu = CANFD_MTU;
 }
 
-/* get data length from can_dlc with sanitized can_dlc */
-u8 can_dlc2len(u8 can_dlc);
+/* get data length from raw data length code (DLC) */
+u8 can_fd_dlc2len(u8 dlc);
 
 /* map the sanitized data length to an appropriate data length code */
-u8 can_len2dlc(u8 len);
+u8 can_fd_len2dlc(u8 len);
 
 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 				    unsigned int txqs, unsigned int rxqs);