| Message ID | 20200617182019.6790-1-dmurphy@ti.com |
|---|---|
| Headers | show |
| Series | RGMII Internal delay common property | expand |
All On 6/17/20 1:20 PM, Dan Murphy wrote: > The DP83822 can be configured to use the RGMII interface. There are > independent fixed 3.5ns clock shift (aka internal delay) for the TX and RX > paths. This allow either one to be set if the MII interface is RGMII and > the value is set in the firmware node. $subject is wrong. I used the 83822 fiber patch as my base as it had 90% of the work done that I needed for the internal delay. I will fix it in v8 after review comments. Dan
On Wed, 17 Jun 2020 13:20:19 -0500 Dan Murphy wrote: > +static int dp83822_config_init(struct phy_device *phydev) > +{ > + struct dp83822_private *dp83822 = phydev->priv; > + int rgmii_delay; > + int err = 0; > + > + if (phy_interface_is_rgmii(phydev)) { > + if (dp83822->rx_int_delay) > + rgmii_delay = DP83822_RX_CLK_SHIFT; > + > + if (dp83822->tx_int_delay) > + rgmii_delay |= DP83822_TX_CLK_SHIFT; > + > + if (rgmii_delay) > + err = phy_set_bits_mmd(phydev, DP83822_DEVADDR, > + MII_DP83822_RCSR, rgmii_delay); > + } > + > + return dp8382x_disable_wol(phydev); > +} drivers/net/phy/dp83822.c: In function dp83822_config_init: drivers/net/phy/dp83822.c:282:6: warning: variable err set but not used [-Wunused-but-set-variable] 282 | int err = 0; | ^~~
On Wed, Jun 17, 2020 at 01:20:14PM -0500, Dan Murphy wrote: > tx-internal-delays and rx-internal-delays are a common setting for RGMII > capable devices. > > These properties are used when the phy-mode or phy-controller is set to > rgmii-id, rgmii-rxid or rgmii-txid. These modes indicate to the > controller that the PHY will add the internal delay for the connection. > > Signed-off-by: Dan Murphy <dmurphy@ti.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Andrew
Andrew On 6/17/20 8:51 PM, Andrew Lunn wrote: > On Wed, Jun 17, 2020 at 01:20:15PM -0500, Dan Murphy wrote: >> Add a helper function that will return the index in the array for the >> passed in internal delay value. The helper requires the array, size and >> delay value. >> >> The helper will then return the index for the exact match or return the >> index for the index to the closest smaller value. >> >> Signed-off-by: Dan Murphy <dmurphy@ti.com> >> --- >> drivers/net/phy/phy_device.c | 68 ++++++++++++++++++++++++++++++++++++ >> include/linux/phy.h | 4 +++ >> 2 files changed, 72 insertions(+) >> >> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c >> index 04946de74fa0..611d4e68e3c6 100644 >> --- a/drivers/net/phy/phy_device.c >> +++ b/drivers/net/phy/phy_device.c >> @@ -31,6 +31,7 @@ >> #include <linux/mdio.h> >> #include <linux/io.h> >> #include <linux/uaccess.h> >> +#include <linux/property.h> >> >> MODULE_DESCRIPTION("PHY library"); >> MODULE_AUTHOR("Andy Fleming"); >> @@ -2657,6 +2658,73 @@ void phy_get_pause(struct phy_device *phydev, bool *tx_pause, bool *rx_pause) >> } >> EXPORT_SYMBOL(phy_get_pause); >> >> +/** >> + * phy_get_delay_index - returns the index of the internal delay >> + * @phydev: phy_device struct >> + * @dev: pointer to the devices device struct >> + * @delay_values: array of delays the PHY supports >> + * @size: the size of the delay array >> + * @is_rx: boolean to indicate to get the rx internal delay >> + * >> + * Returns the index within the array of internal delay passed in. >> + * Or if size == 0 then the delay read from the firmware is returned. >> + * The array must be in ascending order. >> + * Return errno if the delay is invalid or cannot be found. >> + */ >> +s32 phy_get_internal_delay(struct phy_device *phydev, struct device *dev, >> + const int *delay_values, int size, bool is_rx) >> +{ >> + int ret; >> + int i; >> + s32 delay; >> + >> + if (is_rx) >> + ret = device_property_read_u32(dev, "rx-internal-delay-ps", >> + &delay); >> + else >> + ret = device_property_read_u32(dev, "tx-internal-delay-ps", >> + &delay); >> + if (ret) { >> + phydev_err(phydev, "internal delay not defined\n"); > This is an optional property. So printing an error message seems heavy > handed. I will change this to phydev_info > Maybe it would be better to default to 0 if the property is not found, > and continue with the lookup in the table to find what value should be > written for a 0ps delay? If the property is not found what would we look up? The property missing to me indicates that the phy is not adding the delay for that path. If these properties are not present then the delay should not be set by the device driver. This is why I return -EINVAL. Maybe I should return -ENODATA instead. Dan > > Andrew
Andrew On 6/17/20 9:01 PM, Andrew Lunn wrote: > On Wed, Jun 17, 2020 at 01:20:14PM -0500, Dan Murphy wrote: >> tx-internal-delays and rx-internal-delays are a common setting for RGMII >> capable devices. >> >> These properties are used when the phy-mode or phy-controller is set to >> rgmii-id, rgmii-rxid or rgmii-txid. These modes indicate to the >> controller that the PHY will add the internal delay for the connection. >> >> Signed-off-by: Dan Murphy <dmurphy@ti.com> >> --- >> .../devicetree/bindings/net/ethernet-phy.yaml | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/net/ethernet-phy.yaml b/Documentation/devicetree/bindings/net/ethernet-phy.yaml >> index 9b1f1147ca36..b2887476fe6a 100644 >> --- a/Documentation/devicetree/bindings/net/ethernet-phy.yaml >> +++ b/Documentation/devicetree/bindings/net/ethernet-phy.yaml >> @@ -162,6 +162,17 @@ properties: >> description: >> Specifies a reference to a node representing a SFP cage. >> >> + >> + rx-internal-delay-ps: >> + description: | >> + RGMII Receive PHY Clock Delay defined in pico seconds. This is used for >> + PHY's that have configurable RX internal delays. >> + >> + tx-internal-delay-ps: >> + description: | >> + RGMII Transmit PHY Clock Delay defined in pico seconds. This is used for >> + PHY's that have configurable TX internal delays. >> + > So in a later patch you have: > > default: 2000 > > That seems to apply that these values only apply when the phy mode > indicates a delay is needed. It would be good to document that here, > when each of these properties will be used. Also, that they default to > 2000 when not present. The default of 2000ps is for the DP83869 only. The DP83822 fixed delay is 3500ps. So indicating that the default here is 2000ps for all devices is not correct. But I can add a note that if these properties are present then the delay is added by the PHY. Dan > Andrew