This patch to tune on/off the ssc on miphy sata setup. User can now enable ssc via dt blob, it is useful to reduce effects of EMI.
Signed-off-by: Giuseppe Condorelli <[email protected]> Signed-off-by: Gabriel Fernandez <[email protected]> --- .../devicetree/bindings/phy/phy-miphy28lp.txt | 1 + drivers/phy/phy-miphy28lp.c | 34 ++++++++++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/Documentation/devicetree/bindings/phy/phy-miphy28lp.txt b/Documentation/devicetree/bindings/phy/phy-miphy28lp.txt index 1ad4433..daa8310 100644 --- a/Documentation/devicetree/bindings/phy/phy-miphy28lp.txt +++ b/Documentation/devicetree/bindings/phy/phy-miphy28lp.txt @@ -39,6 +39,7 @@ Optional properties (port (child) node): register. - 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). example: diff --git a/drivers/phy/phy-miphy28lp.c b/drivers/phy/phy-miphy28lp.c index 1a468d1..7285543 100644 --- a/drivers/phy/phy-miphy28lp.c +++ b/drivers/phy/phy-miphy28lp.c @@ -200,6 +200,7 @@ struct miphy28lp_phy { bool osc_force_ext; bool osc_rdy; bool px_rx_pol_inv; + bool ssc; struct reset_control *miphy_rst; @@ -550,6 +551,34 @@ static inline void miphy28_usb3_miphy_reset(struct miphy28lp_phy *miphy_phy) writeb_relaxed(0x00, base + MIPHY_CONF); } +static void miphy_sata_tune_ssc(struct miphy28lp_phy *miphy_phy) +{ + u8 val; + + /* Compensate Tx impedance to avoid out of range values */ + /* + * Enable the SSC on PLL for all banks + * SSC Modulation @ 31 KHz and 4000 ppm modulation amp + */ + val = readb_relaxed(miphy_phy->base + MIPHY_BOUNDARY_2); + val |= SSC_EN_SW; + writeb_relaxed(val, miphy_phy->base + MIPHY_BOUNDARY_2); + + val = readb_relaxed(miphy_phy->base + MIPHY_BOUNDARY_SEL); + val |= SSC_SEL; + writeb_relaxed(val, miphy_phy->base + MIPHY_BOUNDARY_SEL); + + for (val = 0; val < 3; val++) { + writeb_relaxed(val, miphy_phy->base + MIPHY_CONF); + writeb_relaxed(0x3c, miphy_phy->base + MIPHY_PLL_SBR_2); + writeb_relaxed(0x6c, miphy_phy->base + MIPHY_PLL_SBR_3); + writeb_relaxed(0x81, miphy_phy->base + MIPHY_PLL_SBR_4); + writeb_relaxed(0x00, miphy_phy->base + MIPHY_PLL_SBR_1); + writeb_relaxed(0x02, miphy_phy->base + MIPHY_PLL_SBR_1); + writeb_relaxed(0x00, miphy_phy->base + MIPHY_PLL_SBR_1); + } +} + static inline int miphy28lp_configure_sata(struct miphy28lp_phy *miphy_phy) { void __iomem *base = miphy_phy->base; @@ -585,6 +614,9 @@ static inline int miphy28lp_configure_sata(struct miphy28lp_phy *miphy_phy) writeb_relaxed(val, miphy_phy->base + MIPHY_CONTROL); } + if (miphy_phy->ssc) + miphy_sata_tune_ssc(miphy_phy); + return 0; } @@ -1051,6 +1083,8 @@ static int miphy28lp_of_probe(struct device_node *np, miphy_phy->px_rx_pol_inv = of_property_read_bool(np, "st,px_rx_pol_inv"); + miphy_phy->ssc = of_property_read_bool(np, "st,ssc-on"); + of_property_read_u32(np, "st,sata-gen", &miphy_phy->sata_gen); if (!miphy_phy->sata_gen) miphy_phy->sata_gen = SATA_GEN1; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
