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SubjectRe: [PATCH 4/6] phy: meson-g12a-usb3-pcie: Add support for PCIe mode
On Wed, Sep 11, 2019 at 02:45:23PM +0200, Neil Armstrong wrote:
> On 11/09/2019 14:19, Andrew Murray wrote:
> > On Sun, Sep 08, 2019 at 01:42:56PM +0000, Neil Armstrong wrote:
> >> This adds extended PCIe PHY functions for the Amlogic G12A
> >> USB3+PCIE Combo PHY to support reset, power_on and power_off for
> >> PCIe exclusively.
> >>
> >> With these callbacks, we can handle all the needed operations of the
> >> Amlogic PCIe controller driver.
> >>
> >> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> >> ---
> >> .../phy/amlogic/phy-meson-g12a-usb3-pcie.c | 70 ++++++++++++++++---
> >> 1 file changed, 61 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c b/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
> >> index ac322d643c7a..08e322789e59 100644
> >> --- a/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
> >> +++ b/drivers/phy/amlogic/phy-meson-g12a-usb3-pcie.c
> >> @@ -50,6 +50,8 @@
> >> #define PHY_R5_PHY_CR_ACK BIT(16)
> >> #define PHY_R5_PHY_BS_OUT BIT(17)
> >>
> >> +#define PCIE_RESET_DELAY 500
> >> +
> >> struct phy_g12a_usb3_pcie_priv {
> >> struct regmap *regmap;
> >> struct regmap *regmap_cr;
> >> @@ -196,6 +198,10 @@ static int phy_g12a_usb3_init(struct phy *phy)
> >> struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
> >> int data, ret;
> >>
> >> + ret = reset_control_reset(priv->reset);
> >> + if (ret)
> >> + return ret;
> >> +
> >
> > Right, so we've moved this to apply to USB only, thus assuming PCI will
> > call .reset for its reset (why the asymmetry?).
>
> Exact, there is no power_on/power_off when USB3 mode is used, and vendor
> always reset the PHY before switching to USB3, but for PCIe, it seems the
> reset and the power_on must be done separately with the PCIe controller init
> and reset in the middle.
>
> I would prefer symmetry aswell :-/

OK.

Thanks,

Andrew Murray

>
> Neil
>
> >
> > Thanks,
> >
> > Andrew Murray
> >
> >> /* Switch PHY to USB3 */
> >> /* TODO figure out how to handle when PCIe was set in the bootloader */
> >> regmap_update_bits(priv->regmap, PHY_R0,
> >> @@ -272,24 +278,64 @@ static int phy_g12a_usb3_init(struct phy *phy)
> >> return 0;
> >> }
> >>
> >> -static int phy_g12a_usb3_pcie_init(struct phy *phy)
> >> +static int phy_g12a_usb3_pcie_power_on(struct phy *phy)
> >> +{
> >> + struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
> >> +
> >> + if (priv->mode == PHY_TYPE_USB3)
> >> + return 0;
> >> +
> >> + regmap_update_bits(priv->regmap, PHY_R0,
> >> + PHY_R0_PCIE_POWER_STATE,
> >> + FIELD_PREP(PHY_R0_PCIE_POWER_STATE, 0x1c));
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static int phy_g12a_usb3_pcie_power_off(struct phy *phy)
> >> +{
> >> + struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
> >> +
> >> + if (priv->mode == PHY_TYPE_USB3)
> >> + return 0;
> >> +
> >> + regmap_update_bits(priv->regmap, PHY_R0,
> >> + PHY_R0_PCIE_POWER_STATE,
> >> + FIELD_PREP(PHY_R0_PCIE_POWER_STATE, 0x1d));
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static int phy_g12a_usb3_pcie_reset(struct phy *phy)
> >> {
> >> struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
> >> int ret;
> >>
> >> - ret = reset_control_reset(priv->reset);
> >> + if (priv->mode == PHY_TYPE_USB3)
> >> + return 0;
> >> +
> >> + ret = reset_control_assert(priv->reset);
> >> if (ret)
> >> return ret;
> >>
> >> + udelay(PCIE_RESET_DELAY);
> >> +
> >> + ret = reset_control_deassert(priv->reset);
> >> + if (ret)
> >> + return ret;
> >> +
> >> + udelay(PCIE_RESET_DELAY);
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static int phy_g12a_usb3_pcie_init(struct phy *phy)
> >> +{
> >> + struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
> >> +
> >> if (priv->mode == PHY_TYPE_USB3)
> >> return phy_g12a_usb3_init(phy);
> >>
> >> - /* Power UP PCIE */
> >> - /* TODO figure out when the bootloader has set USB3 mode before */
> >> - regmap_update_bits(priv->regmap, PHY_R0,
> >> - PHY_R0_PCIE_POWER_STATE,
> >> - FIELD_PREP(PHY_R0_PCIE_POWER_STATE, 0x1c));
> >> -
> >> return 0;
> >> }
> >>
> >> @@ -297,7 +343,10 @@ static int phy_g12a_usb3_pcie_exit(struct phy *phy)
> >> {
> >> struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
> >>
> >> - return reset_control_reset(priv->reset);
> >> + if (priv->mode == PHY_TYPE_USB3)
> >> + return reset_control_reset(priv->reset);
> >> +
> >> + return 0;
> >> }
> >>
> >> static struct phy *phy_g12a_usb3_pcie_xlate(struct device *dev,
> >> @@ -326,6 +375,9 @@ static struct phy *phy_g12a_usb3_pcie_xlate(struct device *dev,
> >> static const struct phy_ops phy_g12a_usb3_pcie_ops = {
> >> .init = phy_g12a_usb3_pcie_init,
> >> .exit = phy_g12a_usb3_pcie_exit,
> >> + .power_on = phy_g12a_usb3_pcie_power_on,
> >> + .power_off = phy_g12a_usb3_pcie_power_off,
> >> + .reset = phy_g12a_usb3_pcie_reset,
> >> .owner = THIS_MODULE,
> >> };
> >>
> >> --
> >> 2.17.1
> >>
>

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