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authorGiuseppe CAVALLARO <peppe.cavallaro@st.com>2012-04-04 04:33:27 +0000
committerDavid S. Miller <davem@davemloft.net>2012-04-04 18:39:24 -0400
commitcd7201f477b965f6c0220b798813c7000bc603c5 (patch)
tree0b5ac87d64a90efc1ddfca8620019c13fd0acad8 /drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
parent18f05d64ec36e27892cc0f55be707762aae053a1 (diff)
downloadop-kernel-dev-cd7201f477b965f6c0220b798813c7000bc603c5.zip
op-kernel-dev-cd7201f477b965f6c0220b798813c7000bc603c5.tar.gz
stmmac: MDC clock dynamically based on the csr clock input
If a specific clk_csr value is passed from the platform this means that the CSR Clock Range selection cannot be changed at run-time and it is fixed (as reported in the driver documentation). Viceversa the driver will try to set the MDC clock dynamically according to the actual clock input. Signed-off-by: Deepak Sikri <deepak.sikri@st.com> Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com> Reviewed-by: Francesco Virlinzi <francesco.virlinzi@st.com> Reviewed-by: David Laight <david.laight@aculab.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.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index ddb47e1..90d5c4c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -163,6 +163,35 @@ static void stmmac_verify_args(void)
pause = PAUSE_TIME;
}
+static void stmmac_clk_csr_set(struct stmmac_priv *priv)
+{
+#ifdef CONFIG_HAVE_CLK
+ u32 clk_rate;
+
+ clk_rate = clk_get_rate(priv->stmmac_clk);
+
+ /* Platform provided default clk_csr would be assumed valid
+ * for all other cases except for the below mentioned ones. */
+ if (!(priv->clk_csr & MAC_CSR_H_FRQ_MASK)) {
+ if (clk_rate < CSR_F_35M)
+ priv->clk_csr = STMMAC_CSR_20_35M;
+ else if ((clk_rate >= CSR_F_35M) && (clk_rate < CSR_F_60M))
+ priv->clk_csr = STMMAC_CSR_35_60M;
+ else if ((clk_rate >= CSR_F_60M) && (clk_rate < CSR_F_100M))
+ priv->clk_csr = STMMAC_CSR_60_100M;
+ else if ((clk_rate >= CSR_F_100M) && (clk_rate < CSR_F_150M))
+ priv->clk_csr = STMMAC_CSR_100_150M;
+ else if ((clk_rate >= CSR_F_150M) && (clk_rate < CSR_F_250M))
+ priv->clk_csr = STMMAC_CSR_150_250M;
+ else if ((clk_rate >= CSR_F_250M) && (clk_rate < CSR_F_300M))
+ priv->clk_csr = STMMAC_CSR_250_300M;
+ } /* For values higher than the IEEE 802.3 specified frequency
+ * we can not estimate the proper divider as it is not known
+ * the frequency of clk_csr_i. So we do not change the default
+ * divider. */
+#endif
+}
+
#if defined(STMMAC_XMIT_DEBUG) || defined(STMMAC_RX_DEBUG)
static void print_pkt(unsigned char *buf, int len)
{
@@ -1890,6 +1919,17 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device,
if (stmmac_clk_get(priv))
goto error;
+ /* If a specific clk_csr value is passed from the platform
+ * this means that the CSR Clock Range selection cannot be
+ * changed at run-time and it is fixed. Viceversa the driver'll try to
+ * set the MDC clock dynamically according to the csr actual
+ * clock input.
+ */
+ if (!priv->plat->clk_csr)
+ stmmac_clk_csr_set(priv);
+ else
+ priv->clk_csr = priv->plat->clk_csr;
+
return priv;
error:
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