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phy: miphy28lp: Tune tx impedance across Soc cuts

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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>
This commit is contained in:
Gabriel FERNANDEZ
2014-11-04 11:51:23 +01:00
committed by Kishon Vijay Abraham I
parent a2108dee3c
commit 28ba384dc5
2 changed files with 17 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Documentation/devicetree/bindings/phy/phy-miphy28lp.txt
+1
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@@ -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 - st,px_rx_pol_inv : to invert polarity of RXn/RXp (respectively negative line and positive
line). line).
- st,scc-on : enable ssc to reduce effects of EMI (only for sata or PCIe). - 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: example:
drivers/phy/phy-miphy28lp.c
+16
View File
@@ -204,6 +204,7 @@ struct miphy28lp_phy {
bool osc_rdy; bool osc_rdy;
bool px_rx_pol_inv; bool px_rx_pol_inv;
bool ssc; bool ssc;
bool tx_impedance;
struct reset_control *miphy_rst; 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) static inline int miphy28lp_configure_sata(struct miphy28lp_phy *miphy_phy)
{ {
void __iomem *base = miphy_phy->base; 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) if (miphy_phy->ssc)
miphy_sata_tune_ssc(miphy_phy); miphy_sata_tune_ssc(miphy_phy);
if (miphy_phy->tx_impedance)
miphy_tune_tx_impedance(miphy_phy);
return 0; return 0;
} }
@@ -703,6 +713,9 @@ static inline int miphy28lp_configure_pcie(struct miphy28lp_phy *miphy_phy)
if (miphy_phy->ssc) if (miphy_phy->ssc)
miphy_pcie_tune_ssc(miphy_phy); miphy_pcie_tune_ssc(miphy_phy);
if (miphy_phy->tx_impedance)
miphy_tune_tx_impedance(miphy_phy);
return 0; 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->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); of_property_read_u32(np, "st,sata-gen", &miphy_phy->sata_gen);
if (!miphy_phy->sata_gen) if (!miphy_phy->sata_gen)
miphy_phy->sata_gen = SATA_GEN1; miphy_phy->sata_gen = SATA_GEN1;