From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx> [ Upstream commit 2d99bfbf3386962692dcccd73931cb0db07a1a43 ] As per Chapter 6.5.16 of the RZ/N1 Peripheral Manual, The SJA1000 CAN controller does not support Clock Divider Register compared to the reference Philips SJA1000 device. This patch adds a device quirk to handle this difference. Link: https://lore.kernel.org/all/20220710115248.190280-4-biju.das.jz@xxxxxxxxxxxxxx Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/can/sja1000/sja1000.c | 8 +++++--- drivers/net/can/sja1000/sja1000.h | 3 ++- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c index 9f107798f904..ae0ca0ab371f 100644 --- a/drivers/net/can/sja1000/sja1000.c +++ b/drivers/net/can/sja1000/sja1000.c @@ -184,8 +184,9 @@ static void chipset_init(struct net_device *dev) { struct sja1000_priv *priv = netdev_priv(dev); - /* set clock divider and output control register */ - priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN); + if (!(priv->flags & SJA1000_QUIRK_NO_CDR_REG)) + /* set clock divider and output control register */ + priv->write_reg(priv, SJA1000_CDR, priv->cdr | CDR_PELICAN); /* set acceptance filter (accept all) */ priv->write_reg(priv, SJA1000_ACCC0, 0x00); @@ -210,7 +211,8 @@ static void sja1000_start(struct net_device *dev) set_reset_mode(dev); /* Initialize chip if uninitialized at this stage */ - if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN)) + if (!(priv->flags & SJA1000_QUIRK_NO_CDR_REG || + priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN)) chipset_init(dev); /* Clear error counters and error code capture */ diff --git a/drivers/net/can/sja1000/sja1000.h b/drivers/net/can/sja1000/sja1000.h index 9d46398f8154..7f736f1df547 100644 --- a/drivers/net/can/sja1000/sja1000.h +++ b/drivers/net/can/sja1000/sja1000.h @@ -145,7 +145,8 @@ /* * Flags for sja1000priv.flags */ -#define SJA1000_CUSTOM_IRQ_HANDLER 0x1 +#define SJA1000_CUSTOM_IRQ_HANDLER BIT(0) +#define SJA1000_QUIRK_NO_CDR_REG BIT(1) /* * SJA1000 private data structure -- 2.35.1
