Re: [PATCH V2 net-next 3/4] bfin_mac: offer a PTP Hardware Clock.

[Bob Liu <lliubbo@gmail.com>]

On Thu, Nov 1, 2012 at 12:27 AM, Richard Cochran
<richardcochran@gmail.com> wrote:
> The BF518 has a PTP time unit that works in a similar way to other MAC
> based clocks, like gianfar, ixp46x, and igb. This patch adds support for
> using the blackfin as a PHC. Although the blackfin hardware does offer a
> few ancillary features, this patch implements only the basic operations.
>
> Compile tested only.
>
> Signed-off-by: Richard Cochran <richardcochran@gmail.com>

Tested-by: Bob Liu <lliubbo@gmail.com>

> ---
>  drivers/net/ethernet/adi/Kconfig    |    2 +-
>  drivers/net/ethernet/adi/bfin_mac.c |  170 ++++++++++++++++++++++++++++++++++-
>  drivers/net/ethernet/adi/bfin_mac.h |    6 ++
>  3 files changed, 175 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/adi/Kconfig b/drivers/net/ethernet/adi/Kconfig
> index 49a30d3..175c38c 100644
> --- a/drivers/net/ethernet/adi/Kconfig
> +++ b/drivers/net/ethernet/adi/Kconfig
> @@ -61,7 +61,7 @@ config BFIN_RX_DESC_NUM
>
>  config BFIN_MAC_USE_HWSTAMP
>         bool "Use IEEE 1588 hwstamp"
> -       depends on BFIN_MAC && BF518
> +       depends on BFIN_MAC && BF518 && PTP_1588_CLOCK && !(BFIN_MAC=y && PTP_1588_CLOCK=m)
>         default y
>         ---help---
>           To support the IEEE 1588 Precision Time Protocol (PTP), select y here
> diff --git a/drivers/net/ethernet/adi/bfin_mac.c b/drivers/net/ethernet/adi/bfin_mac.c
> index 885fa80..f1c458d 100644
> --- a/drivers/net/ethernet/adi/bfin_mac.c
> +++ b/drivers/net/ethernet/adi/bfin_mac.c
> @@ -552,11 +552,13 @@ static int bfin_mac_ethtool_setwol(struct net_device *dev,
>  static int bfin_mac_ethtool_get_ts_info(struct net_device *dev,
>         struct ethtool_ts_info *info)
>  {
> +       struct bfin_mac_local *lp = netdev_priv(dev);
> +
>         info->so_timestamping =
>                 SOF_TIMESTAMPING_TX_HARDWARE |
>                 SOF_TIMESTAMPING_RX_HARDWARE |
>                 SOF_TIMESTAMPING_RAW_HARDWARE;
> -       info->phc_index = -1;
> +       info->phc_index = lp->phc_index;
>         info->tx_types =
>                 (1 << HWTSTAMP_TX_OFF) |
>                 (1 << HWTSTAMP_TX_ON);
> @@ -887,7 +889,7 @@ static void bfin_rx_hwtstamp(struct net_device *netdev, struct sk_buff *skb)
>  static void bfin_mac_hwtstamp_init(struct net_device *netdev)
>  {
>         struct bfin_mac_local *lp = netdev_priv(netdev);
> -       u64 addend;
> +       u64 addend, ppb;
>         u32 input_clk, phc_clk;
>
>         /* Initialize hardware timer */
> @@ -898,18 +900,175 @@ static void bfin_mac_hwtstamp_init(struct net_device *netdev)
>         bfin_write_EMAC_PTP_ADDEND((u32)addend);
>
>         lp->addend = addend;
> +       ppb = 1000000000ULL * input_clk;
> +       do_div(ppb, phc_clk);
> +       lp->max_ppb = ppb - 1000000000ULL - 1ULL;
>
>         /* Initialize hwstamp config */
>         lp->stamp_cfg.rx_filter = HWTSTAMP_FILTER_NONE;
>         lp->stamp_cfg.tx_type = HWTSTAMP_TX_OFF;
>  }
>
> +static u64 bfin_ptp_time_read(struct bfin_mac_local *lp)
> +{
> +       u64 ns;
> +       u32 lo, hi;
> +
> +       lo = bfin_read_EMAC_PTP_TIMELO();
> +       hi = bfin_read_EMAC_PTP_TIMEHI();
> +
> +       ns = ((u64) hi) << 32;
> +       ns |= lo;
> +       ns <<= lp->shift;
> +
> +       return ns;
> +}
> +
> +static void bfin_ptp_time_write(struct bfin_mac_local *lp, u64 ns)
> +{
> +       u32 hi, lo;
> +
> +       ns >>= lp->shift;
> +       hi = ns >> 32;
> +       lo = ns & 0xffffffff;
> +
> +       bfin_write_EMAC_PTP_TIMELO(lo);
> +       bfin_write_EMAC_PTP_TIMEHI(hi);
> +}
> +
> +/* PTP Hardware Clock operations */
> +
> +static int bfin_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
> +{
> +       u64 adj;
> +       u32 diff, addend;
> +       int neg_adj = 0;
> +       struct bfin_mac_local *lp =
> +               container_of(ptp, struct bfin_mac_local, caps);
> +
> +       if (ppb < 0) {
> +               neg_adj = 1;
> +               ppb = -ppb;
> +       }
> +       addend = lp->addend;
> +       adj = addend;
> +       adj *= ppb;
> +       diff = div_u64(adj, 1000000000ULL);
> +
> +       addend = neg_adj ? addend - diff : addend + diff;
> +
> +       bfin_write_EMAC_PTP_ADDEND(addend);
> +
> +       return 0;
> +}
> +
> +static int bfin_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
> +{
> +       s64 now;
> +       unsigned long flags;
> +       struct bfin_mac_local *lp =
> +               container_of(ptp, struct bfin_mac_local, caps);
> +
> +       spin_lock_irqsave(&lp->phc_lock, flags);
> +
> +       now = bfin_ptp_time_read(lp);
> +       now += delta;
> +       bfin_ptp_time_write(lp, now);
> +
> +       spin_unlock_irqrestore(&lp->phc_lock, flags);
> +
> +       return 0;
> +}
> +
> +static int bfin_ptp_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
> +{
> +       u64 ns;
> +       u32 remainder;
> +       unsigned long flags;
> +       struct bfin_mac_local *lp =
> +               container_of(ptp, struct bfin_mac_local, caps);
> +
> +       spin_lock_irqsave(&lp->phc_lock, flags);
> +
> +       ns = bfin_ptp_time_read(lp);
> +
> +       spin_unlock_irqrestore(&lp->phc_lock, flags);
> +
> +       ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
> +       ts->tv_nsec = remainder;
> +       return 0;
> +}
> +
> +static int bfin_ptp_settime(struct ptp_clock_info *ptp,
> +                          const struct timespec *ts)
> +{
> +       u64 ns;
> +       unsigned long flags;
> +       struct bfin_mac_local *lp =
> +               container_of(ptp, struct bfin_mac_local, caps);
> +
> +       ns = ts->tv_sec * 1000000000ULL;
> +       ns += ts->tv_nsec;
> +
> +       spin_lock_irqsave(&lp->phc_lock, flags);
> +
> +       bfin_ptp_time_write(lp, ns);
> +
> +       spin_unlock_irqrestore(&lp->phc_lock, flags);
> +
> +       return 0;
> +}
> +
> +static int bfin_ptp_enable(struct ptp_clock_info *ptp,
> +                         struct ptp_clock_request *rq, int on)
> +{
> +       return -EOPNOTSUPP;
> +}
> +
> +static struct ptp_clock_info bfin_ptp_caps = {
> +       .owner          = THIS_MODULE,
> +       .name           = "BF518 clock",
> +       .max_adj        = 0,
> +       .n_alarm        = 0,
> +       .n_ext_ts       = 0,
> +       .n_per_out      = 0,
> +       .pps            = 0,
> +       .adjfreq        = bfin_ptp_adjfreq,
> +       .adjtime        = bfin_ptp_adjtime,
> +       .gettime        = bfin_ptp_gettime,
> +       .settime        = bfin_ptp_settime,
> +       .enable         = bfin_ptp_enable,
> +};
> +
> +static int bfin_phc_init(struct net_device *netdev, struct device *dev)
> +{
> +       struct bfin_mac_local *lp = netdev_priv(netdev);
> +
> +       lp->caps = bfin_ptp_caps;
> +       lp->caps.max_adj = lp->max_ppb;
> +       lp->clock = ptp_clock_register(&lp->caps, dev);
> +       if (IS_ERR(lp->clock))
> +               return PTR_ERR(lp->clock);
> +
> +       lp->phc_index = ptp_clock_index(lp->clock);
> +       spin_lock_init(&lp->phc_lock);
> +
> +       return 0;
> +}
> +
> +static void bfin_phc_release(struct bfin_mac_local *lp)
> +{
> +       ptp_clock_unregister(lp->clock);
> +}
> +
>  #else
>  # define bfin_mac_hwtstamp_is_none(cfg) 0
>  # define bfin_mac_hwtstamp_init(dev)
>  # define bfin_mac_hwtstamp_ioctl(dev, ifr, cmd) (-EOPNOTSUPP)
>  # define bfin_rx_hwtstamp(dev, skb)
>  # define bfin_tx_hwtstamp(dev, skb)
> +# define bfin_phc_init(netdev, dev) 0
> +# define bfin_phc_release(lp)
>  #endif
>
>  static inline void _tx_reclaim_skb(void)
> @@ -1544,12 +1703,17 @@ static int __devinit bfin_mac_probe(struct platform_device *pdev)
>         }
>
>         bfin_mac_hwtstamp_init(ndev);
> +       if (bfin_phc_init(ndev, &pdev->dev)) {
> +               dev_err(&pdev->dev, "Cannot register PHC device!\n");
> +               goto out_err_phc;
> +       }
>
>         /* now, print out the card info, in a short format.. */
>         netdev_info(ndev, "%s, Version %s\n", DRV_DESC, DRV_VERSION);
>
>         return 0;
>
> +out_err_phc:
>  out_err_reg_ndev:
>         free_irq(IRQ_MAC_RX, ndev);
>  out_err_request_irq:
> @@ -1568,6 +1732,8 @@ static int __devexit bfin_mac_remove(struct platform_device *pdev)
>         struct net_device *ndev = platform_get_drvdata(pdev);
>         struct bfin_mac_local *lp = netdev_priv(ndev);
>
> +       bfin_phc_release(lp);
> +
>         platform_set_drvdata(pdev, NULL);
>
>         lp->mii_bus->priv = NULL;
> diff --git a/drivers/net/ethernet/adi/bfin_mac.h b/drivers/net/ethernet/adi/bfin_mac.h
> index 57f042c..7a07ee0 100644
> --- a/drivers/net/ethernet/adi/bfin_mac.h
> +++ b/drivers/net/ethernet/adi/bfin_mac.h
> @@ -11,6 +11,7 @@
>  #define _BFIN_MAC_H_
>
>  #include <linux/net_tstamp.h>
> +#include <linux/ptp_clock_kernel.h>
>  #include <linux/timer.h>
>  #include <linux/etherdevice.h>
>  #include <linux/bfin_mac.h>
> @@ -94,7 +95,12 @@ struct bfin_mac_local {
>  #if defined(CONFIG_BFIN_MAC_USE_HWSTAMP)
>         u32 addend;
>         unsigned int shift;
> +       s32 max_ppb;
>         struct hwtstamp_config stamp_cfg;
> +       struct ptp_clock_info caps;
> +       struct ptp_clock *clock;
> +       int phc_index;
> +       spinlock_t phc_lock; /* protects time lo/hi registers */
>  #endif
>  };
>
> --
> 1.7.2.5
>



-- 
Regards,
--Bob