From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Walle Subject: Re: [PATCH 2/2] can: flexcan: add support for ISO CAN-FD Date: Tue, 30 Jun 2020 07:53:17 +0200 Message-ID: References: <20200629181809.25338-1-michael@walle.cc> <20200629181809.25338-3-michael@walle.cc> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Sender: netdev-owner@vger.kernel.org To: Joakim Zhang Cc: linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Wolfgang Grandegger , Marc Kleine-Budde , "David S . Miller" , Jakub Kicinski , dl-linux-imx , Oliver Hartkopp List-Id: linux-can.vger.kernel.org [+ Oliver] Hi Joakim, Am 2020-06-30 04:42, schrieb Joakim Zhang: >> -----Original Message----- >> From: Michael Walle >> Sent: 2020年6月30日 2:18 >> To: linux-can@vger.kernel.org; netdev@vger.kernel.org; >> linux-kernel@vger.kernel.org >> Cc: Wolfgang Grandegger ; Marc Kleine-Budde >> ; David S . Miller ; Jakub >> Kicinski ; Joakim Zhang ; >> dl-linux-imx ; Michael Walle >> Subject: [PATCH 2/2] can: flexcan: add support for ISO CAN-FD >> >> Up until now, the controller used non-ISO CAN-FD mode, although it >> supports it. >> Add support for ISO mode, too. By default the hardware is in non-ISO >> mode and >> an enable bit has to be explicitly set. >> >> Signed-off-by: Michael Walle >> --- >> drivers/net/can/flexcan.c | 19 ++++++++++++++++--- >> 1 file changed, 16 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c >> index >> 183e094f8d66..a92d3cdf4195 100644 >> --- a/drivers/net/can/flexcan.c >> +++ b/drivers/net/can/flexcan.c >> @@ -94,6 +94,7 @@ >> #define FLEXCAN_CTRL2_MRP BIT(18) >> #define FLEXCAN_CTRL2_RRS BIT(17) >> #define FLEXCAN_CTRL2_EACEN BIT(16) >> +#define FLEXCAN_CTRL2_ISOCANFDEN BIT(12) >> >> /* FLEXCAN memory error control register (MECR) bits */ >> #define FLEXCAN_MECR_ECRWRDIS BIT(31) >> @@ -1344,14 +1345,25 @@ static int flexcan_chip_start(struct >> net_device >> *dev) >> else >> reg_mcr |= FLEXCAN_MCR_SRX_DIS; >> >> - /* MCR - CAN-FD */ >> - if (priv->can.ctrlmode & CAN_CTRLMODE_FD) >> + /* MCR, CTRL2 >> + * >> + * CAN-FD mode >> + * ISO CAN-FD mode >> + */ >> + reg_ctrl2 = priv->read(®s->ctrl2); >> + if (priv->can.ctrlmode & CAN_CTRLMODE_FD) { >> reg_mcr |= FLEXCAN_MCR_FDEN; >> - else >> + reg_ctrl2 |= FLEXCAN_CTRL2_ISOCANFDEN; >> + } else { >> reg_mcr &= ~FLEXCAN_MCR_FDEN; >> + } >> + >> + if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO) >> + reg_ctrl2 &= ~FLEXCAN_CTRL2_ISOCANFDEN; > > [..] > ip link set can0 up type can bitrate 1000000 dbitrate 5000000 fd on > ip link set can0 up type can bitrate 1000000 dbitrate 5000000 fd on \ > fd-non-iso on vs. > ip link set can0 up type can bitrate 1000000 dbitrate 5000000 > fd-non-iso on I haven't found anything if CAN_CTRLMODE_FD_NON_ISO depends on CAN_CTRLMODE_FD. I.e. wether CAN_CTRLMODE_FD_NON_ISO can only be set if CAN_CTRLMODE_FD is also set. Only the following piece of code, which might be a hint that you have to set CAN_CTRLMODE_FD if you wan't to use CAN_CTRLMODE_FD_NON_ISO: drivers/net/can/dev.c: /* do not check for static fd-non-iso if 'fd' is disabled */ if (!(maskedflags & CAN_CTRLMODE_FD)) ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO; If CAN_CTRLMODE_FD_NON_ISO can be set without CAN_CTRLMODE_FD, what should be the mode if both are set at the same time? Marc? Oliver? -michael