Re: [RFC PATCH 06/10] net: ti: prueth: Adds HW timestamping support for PTP using PRU-ICSS IEP module

Jason Xing
2025-01-11T23:38:41Z

On Fri, Jan 10, 2025 at 2:01 PM Basharath Hussain Khaja
<basharath@couthit.com> wrote:
>
> From: Roger Quadros <rogerq@ti.com>
>
> PRU-ICSS IEP module, which is capable of timestamping RX and
> TX packets at HW level, is used for time synchronization by PTP4L.
>
> This change includes interaction between firmware and user space
> application (ptp4l) with required packet timestamps. The driver
> initializes the PRU firmware with appropriate mode and configuration
> flags. Firmware updates local registers with the flags set by driver
> and uses for further operation. RX SOF timestamp comes along with
> packet and firmware will rise interrupt with TX SOF timestamp after
> pushing the packet on to the wire.
>
> IEP driver is available in upstream and we are reusing for hardware
> configuration for ICSSM as well. On top of that we have extended it
> with the changes for AM57xx SoC.
>
> Extended ethtool for reading HW timestamping capability of the PRU
> interfaces.
>
> Currently ordinary clock (OC) configuration has been validated with
> Linux ptp4l.
>
> Signed-off-by: Roger Quadros <rogerq@ti.com>
> Signed-off-by: Andrew F. Davis <afd@ti.com>
> Signed-off-by: Parvathi Pudi <parvathi@couthit.com>
> Signed-off-by: Basharath Hussain Khaja <basharath@couthit.com>
> ---
> drivers/net/ethernet/ti/icssg/icss_iep.c | 42 ++
> drivers/net/ethernet/ti/icssm/icssm_ethtool.c | 26 +
> drivers/net/ethernet/ti/icssm/icssm_prueth.c | 443 +++++++++++++++++-
> drivers/net/ethernet/ti/icssm/icssm_prueth.h | 11 +
> .../net/ethernet/ti/icssm/icssm_prueth_ptp.h | 85 ++++
> 5 files changed, 605 insertions(+), 2 deletions(-)
> create mode 100644 drivers/net/ethernet/ti/icssm/icssm_prueth_ptp.h
>
> diff --git a/drivers/net/ethernet/ti/icssg/icss_iep.c b/drivers/net/ethernet/ti/icssg/icss_iep.c
> index 768578c0d958..9a2ea13703d8 100644
> --- a/drivers/net/ethernet/ti/icssg/icss_iep.c
> +++ b/drivers/net/ethernet/ti/icssg/icss_iep.c
> @@ -937,11 +937,53 @@ static const struct icss_iep_plat_data am654_icss_iep_plat_data = {
> .config = &am654_icss_iep_regmap_config,
> };
>
> +static const struct icss_iep_plat_data am57xx_icss_iep_plat_data = {
> + .flags = ICSS_IEP_64BIT_COUNTER_SUPPORT |
> + ICSS_IEP_SLOW_COMPEN_REG_SUPPORT,
> + .reg_offs = {
> + [ICSS_IEP_GLOBAL_CFG_REG] = 0x00,
> + [ICSS_IEP_COMPEN_REG] = 0x08,
> + [ICSS_IEP_SLOW_COMPEN_REG] = 0x0C,
> + [ICSS_IEP_COUNT_REG0] = 0x10,
> + [ICSS_IEP_COUNT_REG1] = 0x14,
> + [ICSS_IEP_CAPTURE_CFG_REG] = 0x18,
> + [ICSS_IEP_CAPTURE_STAT_REG] = 0x1c,
> +
> + [ICSS_IEP_CAP6_RISE_REG0] = 0x50,
> + [ICSS_IEP_CAP6_RISE_REG1] = 0x54,
> +
> + [ICSS_IEP_CAP7_RISE_REG0] = 0x60,
> + [ICSS_IEP_CAP7_RISE_REG1] = 0x64,
> +
> + [ICSS_IEP_CMP_CFG_REG] = 0x70,
> + [ICSS_IEP_CMP_STAT_REG] = 0x74,
> + [ICSS_IEP_CMP0_REG0] = 0x78,
> + [ICSS_IEP_CMP0_REG1] = 0x7c,
> + [ICSS_IEP_CMP1_REG0] = 0x80,
> + [ICSS_IEP_CMP1_REG1] = 0x84,
> +
> + [ICSS_IEP_CMP8_REG0] = 0xc0,
> + [ICSS_IEP_CMP8_REG1] = 0xc4,
> + [ICSS_IEP_SYNC_CTRL_REG] = 0x180,
> + [ICSS_IEP_SYNC0_STAT_REG] = 0x188,
> + [ICSS_IEP_SYNC1_STAT_REG] = 0x18c,
> + [ICSS_IEP_SYNC_PWIDTH_REG] = 0x190,
> + [ICSS_IEP_SYNC0_PERIOD_REG] = 0x194,
> + [ICSS_IEP_SYNC1_DELAY_REG] = 0x198,
> + [ICSS_IEP_SYNC_START_REG] = 0x19c,
> + },
> + .config = &am654_icss_iep_regmap_config,
> +};
> +
> static const struct of_device_id icss_iep_of_match[] = {
> {
> .compatible = "ti,am654-icss-iep",
> .data = &am654_icss_iep_plat_data,
> },
> + {
> + .compatible = "ti,am5728-icss-iep",
> + .data = &am57xx_icss_iep_plat_data,
> + },
> {},
> };
> MODULE_DEVICE_TABLE(of, icss_iep_of_match);
> diff --git a/drivers/net/ethernet/ti/icssm/icssm_ethtool.c b/drivers/net/ethernet/ti/icssm/icssm_ethtool.c
> index cce3276d5565..86d62d64dc4d 100644
> --- a/drivers/net/ethernet/ti/icssm/icssm_ethtool.c
> +++ b/drivers/net/ethernet/ti/icssm/icssm_ethtool.c
> @@ -7,6 +7,7 @@
>
> #include <linux/if_bridge.h>
> #include "icssm_prueth.h"
> +#include "../icssg/icss_iep.h"
>
> #define PRUETH_MODULE_VERSION "0.2"
> #define PRUETH_MODULE_DESCRIPTION "PRUSS Ethernet driver"
> @@ -189,12 +190,37 @@ static void icssm_emac_get_regs(struct net_device *ndev,
> regs->version = PRUETH_REG_DUMP_GET_VER(prueth);
> }
>
> +static int icssm_emac_get_ts_info(struct net_device *ndev,
> + struct kernel_ethtool_ts_info *info)
> +{
> + struct prueth_emac *emac = netdev_priv(ndev);
> +
> + if ((PRUETH_IS_EMAC(emac->prueth) && !emac->emac_ptp_tx_irq))
> + return ethtool_op_get_ts_info(ndev, info);
> +
> + info->so_timestamping =
> + SOF_TIMESTAMPING_TX_HARDWARE |
> + SOF_TIMESTAMPING_TX_SOFTWARE |
> + SOF_TIMESTAMPING_RX_HARDWARE |
> + SOF_TIMESTAMPING_RX_SOFTWARE |
> + SOF_TIMESTAMPING_SOFTWARE |
> + SOF_TIMESTAMPING_RAW_HARDWARE;

In addtion to what Richard suggested, there is no need to re-mark the
following flags "SOF_TIMESTAMPING_RX_SOFTWARE" and
"SOF_TIMESTAMPING_SOFTWARE", please see __ethtool_get_ts_info().

Thanks,
Jason