[PATCH v2] flexcan: disable bus error interrupts for the i.MX28
From: Wolfgang Grandegger <hidden>
Date: 2012-10-10 19:10:44
Also in:
netdev
Subsystem:
can network drivers, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds
Due to a bug in most Flexcan cores, the bus error interrupt needs to be enabled. Otherwise we don't get any error warning or passive interrupts. This is _not_ necessary for the i.MX28 and this patch disables bus error interrupts if "berr-reporting" is not requested. This avoids bus error flooding, which might harm, especially on low-end systems. To handle such quirks of the Flexcan cores, a hardware feature flag has been introduced, also replacing the "hw_ver" variable. We got some version info about what Flexcan core version is available on what Freescale SOC which have been summarized as comment. Changes since v1: - add known version info and hw bugs as comment - remove FLEXCAN_HAS_BROKEN_ERR_STATE for i.MX6Q CC: Hui Wang <redacted> CC: Shawn Guo <redacted> Signed-off-by: Wolfgang Grandegger <redacted> --- drivers/net/can/flexcan.c | 42 ++++++++++++++++++++++++++++++++---------- 1 files changed, 32 insertions(+), 10 deletions(-)
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index c5f1431..f07128b 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c@@ -144,6 +144,23 @@ #define FLEXCAN_MB_CODE_MASK (0xf0ffffff) +/* + * FLEXCAN hardware feature flags + * + * Below is some version info we got: + * SOC Version IP-Version Glitch- [TR]WRN_INT + * Filter? connected? + * MX25 FlexCAN2 03.00.00.00 no no + * MX28 FlexCAN2 03.00.04.00 yes yes + * MX35 FlexCAN2 03.00.00.00 no no + * MX53 FlexCAN2 03.00.00.00 yes no + * MX6s FlexCAN3 10.00.12.00 ? yes + * + * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected. + */ +#define FLEXCAN_HAS_V10_FEATURES BIT(1) /* For core version >= 10 */ +#define FLEXCAN_HAS_BROKEN_ERR_STATE BIT(2) /* [TR]WRN_INT not connected */ + /* Structure of the message buffer */ struct flexcan_mb { u32 can_ctrl;
@@ -178,7 +195,7 @@ struct flexcan_regs { }; struct flexcan_devtype_data { - u32 hw_ver; /* hardware controller version */ + u32 features; /* hardware controller features */ }; struct flexcan_priv {
@@ -197,11 +214,11 @@ struct flexcan_priv { }; static struct flexcan_devtype_data fsl_p1010_devtype_data = { - .hw_ver = 3, + .features = FLEXCAN_HAS_BROKEN_ERR_STATE, }; - +static struct flexcan_devtype_data fsl_imx28_devtype_data; static struct flexcan_devtype_data fsl_imx6q_devtype_data = { - .hw_ver = 10, + .features = FLEXCAN_HAS_V10_FEATURES, }; static const struct can_bittiming_const flexcan_bittiming_const = {
@@ -741,15 +758,19 @@ static int flexcan_chip_start(struct net_device *dev) * enable tx and rx warning interrupt * enable bus off interrupt * (== FLEXCAN_CTRL_ERR_STATE) - * - * _note_: we enable the "error interrupt" - * (FLEXCAN_CTRL_ERR_MSK), too. Otherwise we don't get any - * warning or bus passive interrupts. */ reg_ctrl = flexcan_read(®s->ctrl); reg_ctrl &= ~FLEXCAN_CTRL_TSYN; reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF | - FLEXCAN_CTRL_ERR_STATE | FLEXCAN_CTRL_ERR_MSK; + FLEXCAN_CTRL_ERR_STATE; + /* + * enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK), + * on most Flexcan cores, too. Otherwise we don't get + * any error warning or passive interrupts. + */ + if (priv->devtype_data->features & FLEXCAN_HAS_BROKEN_ERR_STATE || + priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) + reg_ctrl |= FLEXCAN_CTRL_ERR_MSK; /* save for later use */ priv->reg_ctrl_default = reg_ctrl;
@@ -772,7 +793,7 @@ static int flexcan_chip_start(struct net_device *dev) flexcan_write(0x0, ®s->rx14mask); flexcan_write(0x0, ®s->rx15mask); - if (priv->devtype_data->hw_ver >= 10) + if (priv->devtype_data->features & FLEXCAN_HAS_V10_FEATURES) flexcan_write(0x0, ®s->rxfgmask); flexcan_transceiver_switch(priv, 1);
@@ -954,6 +975,7 @@ static void __devexit unregister_flexcandev(struct net_device *dev) static const struct of_device_id flexcan_of_match[] = { { .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, }, + { .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, }, { .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, }, { /* sentinel */ }, };
--
1.7.7.6