Re: [uclinux-dist-devel] [PATCH RFC net-next 2/4] bfin_mac: replace sys time stamps with raw ones instead.
From: Bob Liu <hidden>
Date: 2012-10-31 06:47:24
On Sat, Sep 29, 2012 at 1:20 AM, Richard Cochran [off-list ref] wrote:
quoted hunk ↗ jump to hunk
This patch replaces the sys time stamps and timecompare code with simple raw hardware time stamps in nanosecond resolution. The only tricky bit is to find a PTP Hardware Clock period slower than the input clock period and a power of two. Compile tested only. Signed-off-by: Richard Cochran <richardcochran@gmail.com> --- drivers/net/ethernet/adi/bfin_mac.c | 91 ++++++++++------------------------- drivers/net/ethernet/adi/bfin_mac.h | 7 +-- 2 files changed, 28 insertions(+), 70 deletions(-)diff --git a/drivers/net/ethernet/adi/bfin_mac.c b/drivers/net/ethernet/adi/bfin_mac.c index 2349abb..393d1b5 100644 --- a/drivers/net/ethernet/adi/bfin_mac.c +++ b/drivers/net/ethernet/adi/bfin_mac.c@@ -555,7 +555,7 @@ static int bfin_mac_ethtool_get_ts_info(struct net_device *dev, info->so_timestamping = SOF_TIMESTAMPING_TX_HARDWARE | SOF_TIMESTAMPING_RX_HARDWARE | - SOF_TIMESTAMPING_SYS_HARDWARE; + SOF_TIMESTAMPING_RAW_HARDWARE; info->phc_index = -1; info->tx_types = (1 << HWTSTAMP_TX_OFF) |@@ -653,6 +653,20 @@ static int bfin_mac_set_mac_address(struct net_device *dev, void *p) #ifdef CONFIG_BFIN_MAC_USE_HWSTAMP #define bfin_mac_hwtstamp_is_none(cfg) ((cfg) == HWTSTAMP_FILTER_NONE) +static u32 bfin_select_phc_clock(u32 input_clk, unsigned int *shift_result) +{ + u32 ipn = 1000000000UL / input_clk; + u32 ppn = 1; + unsigned int shift = 0; + + while (ppn <= ipn) { + ppn <<= 1; + shift++; + } + *shift_result = shift; + return 1000000000UL / ppn; +} + static int bfin_mac_hwtstamp_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd) {@@ -802,19 +816,7 @@ static int bfin_mac_hwtstamp_ioctl(struct net_device *netdev, bfin_read_EMAC_PTP_TXSNAPLO(); bfin_read_EMAC_PTP_TXSNAPHI(); - /* - * Set registers so that rollover occurs soon to test this. - */ - bfin_write_EMAC_PTP_TIMELO(0x00000000); - bfin_write_EMAC_PTP_TIMEHI(0xFF800000); - SSYNC(); - - lp->compare.last_update = 0; - timecounter_init(&lp->clock, - &lp->cycles, - ktime_to_ns(ktime_get_real())); - timecompare_update(&lp->compare, 0); } lp->stamp_cfg = config;@@ -822,15 +824,6 @@ static int bfin_mac_hwtstamp_ioctl(struct net_device *netdev, -EFAULT : 0; } -static void bfin_dump_hwtamp(char *s, ktime_t *hw, ktime_t *ts, struct timecompare *cmp) -{ - ktime_t sys = ktime_get_real(); - - pr_debug("%s %s hardware:%d,%d transform system:%d,%d system:%d,%d, cmp:%lld, %lld\n", - __func__, s, hw->tv.sec, hw->tv.nsec, ts->tv.sec, ts->tv.nsec, sys.tv.sec, - sys.tv.nsec, cmp->offset, cmp->skew); -} - static void bfin_tx_hwtstamp(struct net_device *netdev, struct sk_buff *skb) { struct bfin_mac_local *lp = netdev_priv(netdev);@@ -861,15 +854,9 @@ static void bfin_tx_hwtstamp(struct net_device *netdev, struct sk_buff *skb) regval = bfin_read_EMAC_PTP_TXSNAPLO(); regval |= (u64)bfin_read_EMAC_PTP_TXSNAPHI() << 32; memset(&shhwtstamps, 0, sizeof(shhwtstamps)); - ns = timecounter_cyc2time(&lp->clock, - regval); - timecompare_update(&lp->compare, ns); + ns = regval >> lp->shift;
Why not set ns = regval << lp->shift?
I think it's conflicted with patch [3/4]
+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;
+}
quoted hunk ↗ jump to hunk
shhwtstamps.hwtstamp = ns_to_ktime(ns); - shhwtstamps.syststamp = - timecompare_transform(&lp->compare, ns); skb_tstamp_tx(skb, &shhwtstamps); - - bfin_dump_hwtamp("TX", &shhwtstamps.hwtstamp, &shhwtstamps.syststamp, &lp->compare); } } }@@ -892,51 +879,25 @@ static void bfin_rx_hwtstamp(struct net_device *netdev, struct sk_buff *skb) regval = bfin_read_EMAC_PTP_RXSNAPLO(); regval |= (u64)bfin_read_EMAC_PTP_RXSNAPHI() << 32; - ns = timecounter_cyc2time(&lp->clock, regval); - timecompare_update(&lp->compare, ns); + ns = regval >> lp->shift;
So is here.
quoted hunk ↗ jump to hunk
memset(shhwtstamps, 0, sizeof(*shhwtstamps)); shhwtstamps->hwtstamp = ns_to_ktime(ns); - shhwtstamps->syststamp = timecompare_transform(&lp->compare, ns); - - bfin_dump_hwtamp("RX", &shhwtstamps->hwtstamp, &shhwtstamps->syststamp, &lp->compare); -} - -/* - * bfin_read_clock - read raw cycle counter (to be used by time counter) - */ -static cycle_t bfin_read_clock(const struct cyclecounter *tc) -{ - u64 stamp; - - stamp = bfin_read_EMAC_PTP_TIMELO(); - stamp |= (u64)bfin_read_EMAC_PTP_TIMEHI() << 32ULL; - - return stamp; } -#define PTP_CLK 25000000 - static void bfin_mac_hwtstamp_init(struct net_device *netdev) { struct bfin_mac_local *lp = netdev_priv(netdev); - u64 append; + u64 addend; + u32 input_clk, phc_clk; /* Initialize hardware timer */ - append = PTP_CLK * (1ULL << 32); - do_div(append, get_sclk()); - bfin_write_EMAC_PTP_ADDEND((u32)append); - - memset(&lp->cycles, 0, sizeof(lp->cycles)); - lp->cycles.read = bfin_read_clock; - lp->cycles.mask = CLOCKSOURCE_MASK(64); - lp->cycles.mult = 1000000000 / PTP_CLK; - lp->cycles.shift = 0; - - /* Synchronize our NIC clock against system wall clock */ - memset(&lp->compare, 0, sizeof(lp->compare)); - lp->compare.source = &lp->clock; - lp->compare.target = ktime_get_real; - lp->compare.num_samples = 10; + input_clk = get_sclk(); + phc_clk = bfin_select_phc_clock(input_clk, &lp->shift); + addend = phc_clk * (1ULL << 32); + do_div(addend, input_clk); + bfin_write_EMAC_PTP_ADDEND((u32)addend); + + lp->addend = addend; /* Initialize hwstamp config */ lp->stamp_cfg.rx_filter = HWTSTAMP_FILTER_NONE;diff --git a/drivers/net/ethernet/adi/bfin_mac.h b/drivers/net/ethernet/adi/bfin_mac.h index 960905c..57f042c 100644 --- a/drivers/net/ethernet/adi/bfin_mac.h +++ b/drivers/net/ethernet/adi/bfin_mac.h@@ -11,8 +11,6 @@ #define _BFIN_MAC_H_ #include <linux/net_tstamp.h> -#include <linux/clocksource.h> -#include <linux/timecompare.h> #include <linux/timer.h> #include <linux/etherdevice.h> #include <linux/bfin_mac.h>@@ -94,9 +92,8 @@ struct bfin_mac_local { struct mii_bus *mii_bus; #if defined(CONFIG_BFIN_MAC_USE_HWSTAMP) - struct cyclecounter cycles; - struct timecounter clock; - struct timecompare compare; + u32 addend; + unsigned int shift; struct hwtstamp_config stamp_cfg; #endif }; --1.7.2.5 _______________________________________________ Uclinux-dist-devel mailing list Uclinux-dist-devel@blackfin.uclinux.org https://blackfin.uclinux.org/mailman/listinfo/uclinux-dist-devel
-- Regards, --Bob