Skip to content

Commit

Permalink
bfin_mac: offer a PTP Hardware Clock.
Browse files Browse the repository at this point in the history 
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
Richard Cochran authored and David S. Miller committed Nov 1, 2012
1 parent bc3c5f6 commit dd87b22
Show file tree
Hide file tree
Showing 3 changed files with 175 additions and 3 deletions.
2 changes: 1 addition & 1 deletion drivers/net/ethernet/adi/Kconfig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down
170 changes: 168 additions & 2 deletions drivers/net/ethernet/adi/bfin_mac.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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 */
Expand All @@ -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)
Expand Down Expand Up @@ -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:
Expand All @@ -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;
Expand Down
6 changes: 6 additions & 0 deletions drivers/net/ethernet/adi/bfin_mac.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -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
};

Expand Down

0 comments on commit dd87b22

Please sign in to comment.