From: Neil Armstrong <narmstrong@baylibre.com>
To: Andrew Murray <andrew.murray@arm.com>
Cc: lorenzo.pieralisi@arm.com, khilman@baylibre.com,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
kishon@ti.com, repk@triplefau.lt, maz@kernel.org,
bhelgaas@google.com, linux-amlogic@lists.infradead.org,
yue.wang@Amlogic.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 4/6] phy: meson-g12a-usb3-pcie: Add support for PCIe mode
Date: Wed, 11 Sep 2019 14:45:23 +0200 [thread overview]
Message-ID: <e4249d3a-9a98-c596-01ae-2917ffd78f17@baylibre.com> (raw)
In-Reply-To: <20190911121954.GS9720@e119886-lin.cambridge.arm.com>
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 :-/
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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next prev parent reply other threads:[~2019-09-11 12:45 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-08 13:42 [PATCH 0/6] arm64: dts: meson-g12: add support for PCIe Neil Armstrong
2019-09-08 13:42 ` [PATCH 1/6] dt-bindings: pci: amlogic,meson-pcie: Add G12A bindings Neil Armstrong
2019-09-11 12:22 ` Andrew Murray
2019-09-11 12:30 ` Neil Armstrong
2019-09-13 14:36 ` [PATCH 1/6] dt-bindings: pci: amlogic, meson-pcie: " Rob Herring
2019-09-08 13:42 ` [PATCH 2/6] PCI: amlogic: Fix probed clock names Neil Armstrong
2019-09-11 10:59 ` Andrew Murray
2019-09-08 13:42 ` [PATCH 3/6] PCI: amlogic: meson: Add support for G12A Neil Armstrong
2019-09-11 11:36 ` Andrew Murray
2019-09-11 12:39 ` Neil Armstrong
2019-09-11 12:58 ` Andrew Murray
2019-09-08 13:42 ` [PATCH 4/6] phy: meson-g12a-usb3-pcie: Add support for PCIe mode Neil Armstrong
2019-09-11 12:19 ` Andrew Murray
2019-09-11 12:45 ` Neil Armstrong [this message]
2019-09-11 12:59 ` Andrew Murray
2019-09-08 13:42 ` [PATCH 5/6] arm64: dts: meson-g12a: Add PCIe node Neil Armstrong
2019-09-08 13:42 ` [PATCH 6/6] arm64: dts: khadas-vim3: add commented support for PCIe Neil Armstrong
2019-09-09 16:37 ` Marc Zyngier
2019-09-09 17:50 ` Neil Armstrong
2019-09-10 9:12 ` Marc Zyngier
2019-09-10 9:14 ` Neil Armstrong
2019-09-11 12:50 ` Andrew Murray
2019-09-11 12:58 ` Neil Armstrong
2019-09-11 13:11 ` Andrew Murray
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