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authorGiuseppe CAVALLARO <peppe.cavallaro@st.com>2014-08-27 10:37:49 +0200
committerDavid S. Miller <davem@davemloft.net>2014-08-29 19:54:36 -0700
commit5566401f2f10556776fd199c11d6a02a5e0b7b95 (patch)
treeb9127a13d0c5df4939c72be2fc618e38e9afaf5c /drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
parent2b78d348f1bc3396ca1662c6a6177a7fb1ca62ff (diff)
downloadblackbird-op-linux-5566401f2f10556776fd199c11d6a02a5e0b7b95.tar.gz
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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.c20
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);
}
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