Merge tag 'linux-can-next-for-5.16-20211024' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2021-10-24

this is a pull request of 15 patches for net-next/master.

The first patch is by Thomas Gleixner and makes use of
hrtimer_forward_now() in the CAN broad cast manager (bcm).

The next patch is by me and changes the type of the variables used in
the CAN bit timing calculation can_fixup_bittiming() to unsigned int.

Vincent Mailhol provides 6 patches targeting the CAN device
infrastructure. The CAN-FD specific Transmitter Delay Compensation
(TDC) is updated and configuration via the CAN netlink interface is
added.

Qing Wang's patch updates the at91 and janz-ican3 drivers to use
sysfs_emit() instead of snprintf() in the sysfs show functions.

Geert Uytterhoeven's patch drops the unneeded ARM dependency from the
rar Kconfig.

Cai Huoqing's patch converts the mscan driver to make use of the
dev_err_probe() helper function.

A patch by me against the gsusb driver changes the printf format
strings to use %u to print unsigned values.

Stephane Grosjean's patch updates the peak_usb CAN-FD driver to use
the 64 bit timestamps provided by the hardware.

The last 2 patches target the xilinx_can driver. Michal Simek provides
a patch that removes repeated word from the kernel-doc and Dongliang
Mu's patch removes a redundant netif_napi_del() from the xcan_remove()
function.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 128 insertions, 26 deletions

diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h
index 9de6e9053e34..20b50baf3a02 100644
--- a/include/linux/can/bittiming.h
+++ b/include/linux/can/bittiming.h
@@ -19,6 +19,9 @@
 /* Megahertz */
 #define CAN_MHZ 1000000UL
 
+#define CAN_CTRLMODE_TDC_MASK					\
+	(CAN_CTRLMODE_TDC_AUTO | CAN_CTRLMODE_TDC_MANUAL)
+
 /*
  * struct can_tdc - CAN FD Transmission Delay Compensation parameters
  *
@@ -28,34 +31,54 @@
  *
  * To solve this issue, ISO 11898-1 introduces in section 11.3.3
  * "Transmitter delay compensation" a SSP (Secondary Sample Point)
- * equal to the distance, in time quanta, from the start of the bit
- * time on the TX pin to the actual measurement on the RX pin.
+ * equal to the distance from the start of the bit time on the TX pin
+ * to the actual measurement on the RX pin.
  *
  * This structure contains the parameters to calculate that SSP.
  *
- * @tdcv: Transmitter Delay Compensation Value. Distance, in time
- *	quanta, from when the bit is sent on the TX pin to when it is
- *	received on the RX pin of the transmitter. Possible options:
+ * -+----------- one bit ----------+-- TX pin
+ *  |<--- Sample Point --->|
  *
- *	  0: automatic mode. The controller dynamically measures @tdcv
- *	  for each transmitted CAN FD frame.
+ *                         --+----------- one bit ----------+-- RX pin
+ *  |<-------- TDCV -------->|
+ *                           |<------- TDCO ------->|
+ *  |<----------- Secondary Sample Point ---------->|
  *
- *	  Other values: manual mode. Use the fixed provided value.
+ * To increase precision, contrary to the other bittiming parameters
+ * which are measured in time quanta, the TDC parameters are measured
+ * in clock periods (also referred as "minimum time quantum" in ISO
+ * 11898-1).
  *
- * @tdco: Transmitter Delay Compensation Offset. Offset value, in time
- *	quanta, defining the distance between the start of the bit
- *	reception on the RX pin of the transceiver and the SSP
- *	position such that SSP = @tdcv + @tdco.
+ * @tdcv: Transmitter Delay Compensation Value. The time needed for
+ *	the signal to propagate, i.e. the distance, in clock periods,
+ *	from the start of the bit on the TX pin to when it is received
+ *	on the RX pin. @tdcv depends on the controller modes:
+ *
+ *	  CAN_CTRLMODE_TDC_AUTO is set: The transceiver dynamically
+ *	  measures @tdcv for each transmitted CAN FD frame and the
+ *	  value provided here should be ignored.
+ *
+ *	  CAN_CTRLMODE_TDC_MANUAL is set: use the fixed provided @tdcv
+ *	  value.
  *
- *	If @tdco is zero, then TDC is disabled and both @tdcv and
- *	@tdcf should be ignored.
+ *	N.B. CAN_CTRLMODE_TDC_AUTO and CAN_CTRLMODE_TDC_MANUAL are
+ *	mutually exclusive. Only one can be set at a time. If both
+ *	CAN_TDC_CTRLMODE_AUTO and CAN_TDC_CTRLMODE_MANUAL are unset,
+ *	TDC is disabled and all the values of this structure should be
+ *	ignored.
+ *
+ * @tdco: Transmitter Delay Compensation Offset. Offset value, in
+ *	clock periods, defining the distance between the start of the
+ *	bit reception on the RX pin of the transceiver and the SSP
+ *	position such that SSP = @tdcv + @tdco.
  *
  * @tdcf: Transmitter Delay Compensation Filter window. Defines the
- *	minimum value for the SSP position in time quanta. If SSP is
- *	less than @tdcf, then no delay compensations occur and the
- *	normal sampling point is used instead. The feature is enabled
- *	if and only if @tdcv is set to zero (automatic mode) and @tdcf
- *	is configured to a value greater than @tdco.
+ *	minimum value for the SSP position in clock periods. If the
+ *	SSP position is less than @tdcf, then no delay compensations
+ *	occur and the normal sampling point is used instead. The
+ *	feature is enabled if and only if @tdcv is set to zero
+ *	(automatic mode) and @tdcf is configured to a value greater
+ *	than @tdco.
  */
 struct can_tdc {
 	u32 tdcv;
@@ -67,19 +90,32 @@ struct can_tdc {
  * struct can_tdc_const - CAN hardware-dependent constant for
  *	Transmission Delay Compensation
  *
- * @tdcv_max: Transmitter Delay Compensation Value maximum value.
- *	Should be set to zero if the controller does not support
- *	manual mode for tdcv.
+ * @tdcv_min: Transmitter Delay Compensation Value minimum value. If
+ *	the controller does not support manual mode for tdcv
+ *	(c.f. flag CAN_CTRLMODE_TDC_MANUAL) then this value is
+ *	ignored.
+ * @tdcv_max: Transmitter Delay Compensation Value maximum value. If
+ *	the controller does not support manual mode for tdcv
+ *	(c.f. flag CAN_CTRLMODE_TDC_MANUAL) then this value is
+ *	ignored.
+ *
+ * @tdco_min: Transmitter Delay Compensation Offset minimum value.
  * @tdco_max: Transmitter Delay Compensation Offset maximum value.
  *	Should not be zero. If the controller does not support TDC,
  *	then the pointer to this structure should be NULL.
+ *
+ * @tdcf_min: Transmitter Delay Compensation Filter window minimum
+ *	value. If @tdcf_max is zero, this value is ignored.
  * @tdcf_max: Transmitter Delay Compensation Filter window maximum
  *	value. Should be set to zero if the controller does not
  *	support this feature.
  */
 struct can_tdc_const {
+	u32 tdcv_min;
 	u32 tdcv_max;
+	u32 tdco_min;
 	u32 tdco_max;
+	u32 tdcf_min;
 	u32 tdcf_max;
 };
 
@@ -87,7 +123,9 @@ struct can_tdc_const {
 int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 		       const struct can_bittiming_const *btc);
 
-void can_calc_tdco(struct net_device *dev);
+void can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const,
+		   const struct can_bittiming *dbt,
+		   u32 *ctrlmode, u32 ctrlmode_supported);
 #else /* !CONFIG_CAN_CALC_BITTIMING */
 static inline int
 can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
@@ -97,7 +135,10 @@ can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
 	return -EINVAL;
 }
 
-static inline void can_calc_tdco(struct net_device *dev)
+static inline void
+can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const,
+	      const struct can_bittiming *dbt,
+	      u32 *ctrlmode, u32 ctrlmode_supported)
 {
 }
 #endif /* CONFIG_CAN_CALC_BITTIMING */
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 2413253e54c7..45f19d9db5ca 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -82,6 +82,7 @@ struct can_priv {
 			    enum can_state *state);
 	int (*do_get_berr_counter)(const struct net_device *dev,
 				   struct can_berr_counter *bec);
+	int (*do_get_auto_tdcv)(const struct net_device *dev, u32 *tdcv);
 
 	unsigned int echo_skb_max;
 	struct sk_buff **echo_skb;
@@ -96,6 +97,39 @@ struct can_priv {
 #endif
 };
 
+static inline bool can_tdc_is_enabled(const struct can_priv *priv)
+{
+	return !!(priv->ctrlmode & CAN_CTRLMODE_TDC_MASK);
+}
+
+/*
+ * can_get_relative_tdco() - TDCO relative to the sample point
+ *
+ * struct can_tdc::tdco represents the absolute offset from TDCV. Some
+ * controllers use instead an offset relative to the Sample Point (SP)
+ * such that:
+ *
+ * SSP = TDCV + absolute TDCO
+ *     = TDCV + SP + relative TDCO
+ *
+ * -+----------- one bit ----------+-- TX pin
+ *  |<--- Sample Point --->|
+ *
+ *                         --+----------- one bit ----------+-- RX pin
+ *  |<-------- TDCV -------->|
+ *                           |<------------------------>| absolute TDCO
+ *                           |<--- Sample Point --->|
+ *                           |                      |<->| relative TDCO
+ *  |<------------- Secondary Sample Point ------------>|
+ */
+static inline s32 can_get_relative_tdco(const struct can_priv *priv)
+{
+	const struct can_bittiming *dbt = &priv->data_bittiming;
+	s32 sample_point_in_tc = (CAN_SYNC_SEG + dbt->prop_seg +
+				  dbt->phase_seg1) * dbt->brp;
+
+	return (s32)priv->tdc.tdco - sample_point_in_tc;
+}
 
 /* helper to define static CAN controller features at device creation time */
 static inline void can_set_static_ctrlmode(struct net_device *dev,
diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h
index f730d443b918..75b85c60efb2 100644
--- a/include/uapi/linux/can/netlink.h
+++ b/include/uapi/linux/can/netlink.h
@@ -101,6 +101,8 @@ struct can_ctrlmode {
 #define CAN_CTRLMODE_PRESUME_ACK	0x40	/* Ignore missing CAN ACKs */
 #define CAN_CTRLMODE_FD_NON_ISO		0x80	/* CAN FD in non-ISO mode */
 #define CAN_CTRLMODE_CC_LEN8_DLC	0x100	/* Classic CAN DLC option */
+#define CAN_CTRLMODE_TDC_AUTO		0x200	/* CAN transiver automatically calculates TDCV */
+#define CAN_CTRLMODE_TDC_MANUAL		0x400	/* TDCV is manually set up by user */
 
 /*
  * CAN device statistics
@@ -134,10 +136,35 @@ enum {
 	IFLA_CAN_BITRATE_CONST,
 	IFLA_CAN_DATA_BITRATE_CONST,
 	IFLA_CAN_BITRATE_MAX,
-	__IFLA_CAN_MAX
+	IFLA_CAN_TDC,
+
+	/* add new constants above here */
+	__IFLA_CAN_MAX,
+	IFLA_CAN_MAX = __IFLA_CAN_MAX - 1
 };
 
-#define IFLA_CAN_MAX	(__IFLA_CAN_MAX - 1)
+/*
+ * CAN FD Transmitter Delay Compensation (TDC)
+ *
+ * Please refer to struct can_tdc_const and can_tdc in
+ * include/linux/can/bittiming.h for further details.
+ */
+enum {
+	IFLA_CAN_TDC_UNSPEC,
+	IFLA_CAN_TDC_TDCV_MIN,	/* u32 */
+	IFLA_CAN_TDC_TDCV_MAX,	/* u32 */
+	IFLA_CAN_TDC_TDCO_MIN,	/* u32 */
+	IFLA_CAN_TDC_TDCO_MAX,	/* u32 */
+	IFLA_CAN_TDC_TDCF_MIN,	/* u32 */
+	IFLA_CAN_TDC_TDCF_MAX,	/* u32 */
+	IFLA_CAN_TDC_TDCV,	/* u32 */
+	IFLA_CAN_TDC_TDCO,	/* u32 */
+	IFLA_CAN_TDC_TDCF,	/* u32 */
+
+	/* add new constants above here */
+	__IFLA_CAN_TDC,
+	IFLA_CAN_TDC_MAX = __IFLA_CAN_TDC - 1
+};
 
 /* u16 termination range: 1..65535 Ohms */
 #define CAN_TERMINATION_DISABLED 0