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Geert Uytterhoeven <geert+renesas@glider.be> says: This patch series adds CAN-FD Transceiver Delay Compensation support to the R-Car CAN-FD driver, after the customary cleanups and refactorings. Changes compared to v1 [1]: - Dropped patch "can: rcar_canfd: Use ndev parameter in rcar_canfd_set_bittiming()", - New patch "[PATCH v2 02/10] can: rcar_canfd: Remove bittiming debug prints", - New patch "[PATCH v2 07/10] can: rcar_canfd: Rename rcar_canfd_setrnc() to rcar_canfd_set_rnc()", - Add Reviewed-by, - Replace function-like RCANFD_F_*() macros by rcar_canfd_f_*() inline functions, - Replace function-like macro RCANFD_FDSTS_TDCR() by bitmask RCANFD_FDSTS_TDCR and helper function rcar_canfd_get_tdcr(), - Replace function-like macro RCANFD_FDSTS_TDCVF() by two bit definitions, - Drop debug print of tdc mode and tdco value. This has been tested on R-Car V4H (White Hawk), V4M (Gray Hawk Single), and E3 (Ebisu-4D[2]), using various data bit rates. Without proper TDC configuration, transmitting at 8 Mbps makes the CAN-FD controller enter BUS-OFF state. The TDCV value as measured by the CAN-FD controller is 4 on all boards tested (base clock 40 MHz, i.e. 25 ns period), and ca. 90 ns as measured by a logic analyzer on Gray Hawk Single. Note that the BSP (predating upstream TDC support), uses a much simpler method: for transfer rates >= 5 Mbps on R-Car Gen4, it enables TDC with a hardcoded (hardware) TDCO value of 2 (i.e. actual 3), which matches the behavior of this series at 8 Mbps. [1] "[PATCH 0/9] can: rcar_canfd: Add support for Transceiver Delay Compensation" https://lore.kernel.org/cover.1748863848.git.geert+renesas@glider.be [2] r8a77990.dtsi configures the CANFD core clock to 40 MHz, limiting transfer rates to 4 Mbps. Enable support for 8 Mbps by adding to ebisu.dtsi: &canfd { assigned-clock-rates = <80000000>; } I plan to send patches to update this on all R-Car Gen3 and RZ/G2 SoCs once this series has reached upstream. Link: https://patch.msgid.link/cover.1749655315.git.geert+renesas@glider.be Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Linux kernel
============
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