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authorGabriel FERNANDEZ <gabriel.fernandez@st.com>2014-11-04 11:51:23 +0100
committerKishon Vijay Abraham I <kishon@ti.com>2014-11-12 18:40:13 +0530
commit28ba384dc5e42a23328dca7e5e72d19e2dd4c9ce (patch)
treeca51e7738bdc49f39b57af9d6c265bb1de0e30bf
parenta2108dee3cd39f7291d013c50c33c2a639a17b42 (diff)
phy: miphy28lp: Tune tx impedance across Soc cuts
This patch to compensate tx impedance (Sata, PCIe) depending on Soc cuts the kernel is built for. Signed-off-by: Giuseppe Condorelli <giuseppe.condorelli@st.com> Signed-off-by: Gabriel Fernandez <gabriel.fernandez@linaro.org> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
-rw-r--r--Documentation/devicetree/bindings/phy/phy-miphy28lp.txt1
-rw-r--r--drivers/phy/phy-miphy28lp.c16
2 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/phy/phy-miphy28lp.txt b/Documentation/devicetree/bindings/phy/phy-miphy28lp.txt
index 4a3b4af3c1e6..46a135dae6b3 100644
--- a/Documentation/devicetree/bindings/phy/phy-miphy28lp.txt
+++ b/Documentation/devicetree/bindings/phy/phy-miphy28lp.txt
@@ -40,6 +40,7 @@ Optional properties (port (child) node):
- st,px_rx_pol_inv : to invert polarity of RXn/RXp (respectively negative line and positive
line).
- st,scc-on : enable ssc to reduce effects of EMI (only for sata or PCIe).
+- st,tx-impedance-comp : to compensate tx impedance avoiding out of range values.
example:
diff --git a/drivers/phy/phy-miphy28lp.c b/drivers/phy/phy-miphy28lp.c
index d8ff8956ed05..87dcc9ab7f23 100644
--- a/drivers/phy/phy-miphy28lp.c
+++ b/drivers/phy/phy-miphy28lp.c
@@ -204,6 +204,7 @@ struct miphy28lp_phy {
bool osc_rdy;
bool px_rx_pol_inv;
bool ssc;
+ bool tx_impedance;
struct reset_control *miphy_rst;
@@ -632,6 +633,12 @@ static void miphy_pcie_tune_ssc(struct miphy28lp_phy *miphy_phy)
}
}
+static inline void miphy_tune_tx_impedance(struct miphy28lp_phy *miphy_phy)
+{
+ /* Compensate Tx impedance to avoid out of range values */
+ writeb_relaxed(0x02, miphy_phy->base + MIPHY_COMP_POSTP);
+}
+
static inline int miphy28lp_configure_sata(struct miphy28lp_phy *miphy_phy)
{
void __iomem *base = miphy_phy->base;
@@ -670,6 +677,9 @@ static inline int miphy28lp_configure_sata(struct miphy28lp_phy *miphy_phy)
if (miphy_phy->ssc)
miphy_sata_tune_ssc(miphy_phy);
+ if (miphy_phy->tx_impedance)
+ miphy_tune_tx_impedance(miphy_phy);
+
return 0;
}
@@ -703,6 +713,9 @@ static inline int miphy28lp_configure_pcie(struct miphy28lp_phy *miphy_phy)
if (miphy_phy->ssc)
miphy_pcie_tune_ssc(miphy_phy);
+ if (miphy_phy->tx_impedance)
+ miphy_tune_tx_impedance(miphy_phy);
+
return 0;
}
@@ -1154,6 +1167,9 @@ static int miphy28lp_of_probe(struct device_node *np,
miphy_phy->ssc = of_property_read_bool(np, "st,ssc-on");
+ miphy_phy->tx_impedance =
+ of_property_read_bool(np, "st,tx-impedance-comp");
+
of_property_read_u32(np, "st,sata-gen", &miphy_phy->sata_gen);
if (!miphy_phy->sata_gen)
miphy_phy->sata_gen = SATA_GEN1;

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