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authorPriyanka Jain <Priyanka.Jain@freescale.com>2014-04-08 10:55:49 +0530
committerYork Sun <yorksun@freescale.com>2014-04-22 17:58:49 -0700
commit2ee6c52e229e1d0d1e78c3efbc67bc8bb868fb25 (patch)
tree4e915a1581f60eaf33769e95bcc9125b3b6f9f10
parent896720ceb2cededcd1f25fa5f5ff23822bea466d (diff)
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driver/net/fm/memac_phy: Initialize mdio_clock for SoCs wih FMANv3
MDIO clock needs to be initialized in u-boot code for SoCs having FMAN-v3(v3H or v3L) controller due to below reasons -On SoCs that have FMAN-v3H like B4860, default value of MDIO_CLK_DIV bits in mdio_stat(mdio_cfg) register generates mdio clock too high (much higher than 2.5MHz), violating the IEEE specs. -On SOCs that have FMAN-v3L like T1040, default value of MDIO_CLK_DIV bits is zero, so MDIO clock is disabled. So, for proper functioninig of MDIO, MDIO_CLK_DIV bits needs to be properly initialized. Also this type of initialization is generally done in PBI(pre-bootloader) phase using rcw.But for chips like T1040 which support deep-sleep, such type of initialization cannot be done in PBI phase due to the limitation that during deep-sleep resume, FMAN (MDIO) registers are not accessible in PBI phase. So, mdio clock initailization must be done as part of u-boot. This initialization code is implemented in memac_phy.c which gets compiled only for SoCs having FMANv3, so no extra compilation flag is required. Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com> Reviewed-by: York Sun <yorksun@freescale.com>
-rw-r--r--drivers/net/fm/memac_phy.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/net/fm/memac_phy.c b/drivers/net/fm/memac_phy.c
index 140e59b..2f4bc11 100644
--- a/drivers/net/fm/memac_phy.c
+++ b/drivers/net/fm/memac_phy.c
@@ -133,5 +133,17 @@ int fm_memac_mdio_init(bd_t *bis, struct memac_mdio_info *info)
bus->priv = info->regs;
+ /*
+ * On some platforms like B4860, default value of MDIO_CLK_DIV bits
+ * in mdio_stat(mdio_cfg) register generates MDIO clock too high
+ * (much higher than 2.5MHz), violating the IEEE specs.
+ * On other platforms like T1040, default value of MDIO_CLK_DIV bits
+ * is zero, so MDIO clock is disabled.
+ * So, for proper functioning of MDIO, MDIO_CLK_DIV bits needs to
+ * be properly initialized.
+ */
+ setbits_be32(&((struct memac_mdio_controller *)info->regs)->mdio_stat,
+ MDIO_STAT_CLKDIV(258));
+
return mdio_register(bus);
}