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author | Giuseppe CAVALLARO <peppe.cavallaro@st.com> | 2014-08-27 10:37:49 +0200 |
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committer | David S. Miller <davem@davemloft.net> | 2014-08-29 19:54:36 -0700 |
commit | 5566401f2f10556776fd199c11d6a02a5e0b7b95 (patch) | |
tree | b9127a13d0c5df4939c72be2fc618e38e9afaf5c /drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | |
parent | 2b78d348f1bc3396ca1662c6a6177a7fb1ca62ff (diff) | |
download | blackbird-op-linux-5566401f2f10556776fd199c11d6a02a5e0b7b95.tar.gz blackbird-op-linux-5566401f2f10556776fd199c11d6a02a5e0b7b95.zip |
stmmac: ptp: fix the reference clock
The PTP reference clock, used for setting the addend in the Timestamp Addend
Register, was erroneously hard-coded (as reported in the databook just as
example).
The patch removes the macro named: STMMAC_SYSCLOCK and allows to use a
reference clock (clk_ptp_ref_i) that can be passed from the platform.
If not passed, the main driver clock will be used as default; note that
this can be fine on some platforms.
Note that, prior this patch, using the old STMMAC_SYSCLOCK on some platforms,
as side effect, the ptp clock can move faster/slower than the system clock.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/stmicro/stmmac/stmmac_main.c')
-rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 51a89d4bb125..03652891fcbf 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -603,16 +603,16 @@ static int stmmac_hwtstamp_ioctl(struct net_device *dev, struct ifreq *ifr) /* calculate default added value: * formula is : * addend = (2^32)/freq_div_ratio; - * where, freq_div_ratio = STMMAC_SYSCLOCK/50MHz - * hence, addend = ((2^32) * 50MHz)/STMMAC_SYSCLOCK; - * NOTE: STMMAC_SYSCLOCK should be >= 50MHz to + * where, freq_div_ratio = clk_ptp_ref_i/50MHz + * hence, addend = ((2^32) * 50MHz)/clk_ptp_ref_i; + * NOTE: clk_ptp_ref_i should be >= 50MHz to * achive 20ns accuracy. * * 2^x * y == (y << x), hence * 2^32 * 50000000 ==> (50000000 << 32) */ temp = (u64) (50000000ULL << 32); - priv->default_addend = div_u64(temp, STMMAC_SYSCLOCK); + priv->default_addend = div_u64(temp, priv->clk_ptp_rate); priv->hw->ptp->config_addend(priv->ioaddr, priv->default_addend); @@ -638,6 +638,16 @@ static int stmmac_init_ptp(struct stmmac_priv *priv) if (!(priv->dma_cap.time_stamp || priv->dma_cap.atime_stamp)) return -EOPNOTSUPP; + /* Fall-back to main clock in case of no PTP ref is passed */ + priv->clk_ptp_ref = devm_clk_get(priv->device, "clk_ptp_ref"); + if (IS_ERR(priv->clk_ptp_ref)) { + priv->clk_ptp_rate = clk_get_rate(priv->stmmac_clk); + priv->clk_ptp_ref = NULL; + } else { + clk_prepare_enable(priv->clk_ptp_ref); + priv->clk_ptp_rate = clk_get_rate(priv->clk_ptp_ref); + } + priv->adv_ts = 0; if (priv->dma_cap.atime_stamp && priv->extend_desc) priv->adv_ts = 1; @@ -657,6 +667,8 @@ static int stmmac_init_ptp(struct stmmac_priv *priv) static void stmmac_release_ptp(struct stmmac_priv *priv) { + if (priv->clk_ptp_ref) + clk_disable_unprepare(priv->clk_ptp_ref); stmmac_ptp_unregister(priv); } |