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| author |   Gabriel FERNANDEZ <gabriel.fernandez@st.com> | 2014-11-04 11:51:23 +0100 |
|---|---|---|
| committer |   Kishon Vijay Abraham I <kishon@ti.com> | 2014-11-12 18:40:13 +0530 |
| commit | 28ba384dc5e42a23328dca7e5e72d19e2dd4c9ce (patch) | |
| tree | ca51e7738bdc49f39b57af9d6c265bb1de0e30bf | |
| parent | phy: miphy28lp: Add SSC support for PCIE (diff) | |
| download | linux-dev-28ba384dc5e42a23328dca7e5e72d19e2dd4c9ce.tar.xz linux-dev-28ba384dc5e42a23328dca7e5e72d19e2dd4c9ce.zip | |
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.txt | 1 | ||||
| -rw-r--r-- | drivers/phy/phy-miphy28lp.c | 16 |
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; |