[PATCH phy-next 13/22] phy: introduce phy_get_max_link_rate() helper for consumers
From: Vladimir Oltean
Date: Wed Mar 04 2026 - 13:06:28 EST
Consumer drivers shouldn't dereference struct phy, not even to get to
its attributes.
We have phy_get_bus_width() as a precedent for getting the bus_width
attribute, so let's add phy_get_max_link_rate() and use it in DRM and
CAN drivers.
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
Cc: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
Cc: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
Cc: Robert Foss <rfoss@xxxxxxxxxx>
Cc: Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Jonas Karlman <jonas@xxxxxxxxx>
Cc: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Maxime Ripard <mripard@xxxxxxxxxx>
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
Cc: David Airlie <airlied@xxxxxxxxx>
Cc: Simona Vetter <simona@xxxxxxxx>
Cc: Andy Yan <andy.yan@xxxxxxxxxxxxxx>
Cc: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Cc: Vincent Mailhol <mailhol@xxxxxxxxxx>
Cc: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Cc: Claudiu Beznea <claudiu.beznea@xxxxxxxxx>
Cc: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx>
Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Cc: Magnus Damm <magnus.damm@xxxxxxxxx>
---
drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c | 4 ++--
drivers/gpu/drm/bridge/synopsys/dw-dp.c | 2 +-
drivers/net/can/at91_can.c | 2 +-
drivers/net/can/flexcan/flexcan-core.c | 2 +-
drivers/net/can/m_can/m_can_platform.c | 2 +-
drivers/net/can/rcar/rcar_canfd.c | 2 +-
drivers/phy/phy-core.c | 6 ++++++
include/linux/phy/phy.h | 6 ++++++
8 files changed, 19 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
index a8b6ae58cb0a..ed7ed82ddb64 100644
--- a/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
+++ b/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c
@@ -1300,7 +1300,7 @@ static u32 cdns_mhdp_get_training_interval_us(struct cdns_mhdp_device *mhdp,
static void cdns_mhdp_fill_host_caps(struct cdns_mhdp_device *mhdp)
{
- unsigned int link_rate;
+ u32 link_rate;
/* Get source capabilities based on PHY attributes */
@@ -1308,7 +1308,7 @@ static void cdns_mhdp_fill_host_caps(struct cdns_mhdp_device *mhdp)
if (!mhdp->host.lanes_cnt)
mhdp->host.lanes_cnt = 4;
- link_rate = mhdp->phy->attrs.max_link_rate;
+ link_rate = phy_get_max_link_rate(mhdp->phy);
if (!link_rate)
link_rate = drm_dp_bw_code_to_link_rate(DP_LINK_BW_8_1);
else
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 4ab6922dd79c..79c72ee8e263 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -536,7 +536,7 @@ static int dw_dp_link_parse(struct dw_dp *dp, struct drm_connector *connector)
link->revision = link->dpcd[DP_DPCD_REV];
link->rate = min_t(u32, min(dp->plat_data.max_link_rate,
- dp->phy->attrs.max_link_rate * 100),
+ phy_get_max_link_rate(dp->phy) * 100),
drm_dp_max_link_rate(link->dpcd));
link->lanes = min_t(u8, phy_get_bus_width(dp->phy),
drm_dp_max_lane_count(link->dpcd));
diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c
index 58da323f14d7..b56db253f02d 100644
--- a/drivers/net/can/at91_can.c
+++ b/drivers/net/can/at91_can.c
@@ -1126,7 +1126,7 @@ static int at91_can_probe(struct platform_device *pdev)
can_rx_offload_add_timestamp(dev, &priv->offload);
if (transceiver)
- priv->can.bitrate_max = transceiver->attrs.max_link_rate;
+ priv->can.bitrate_max = phy_get_max_link_rate(transceiver);
if (at91_is_sam9263(priv))
dev->sysfs_groups[0] = &at91_sysfs_attr_group;
diff --git a/drivers/net/can/flexcan/flexcan-core.c b/drivers/net/can/flexcan/flexcan-core.c
index f5d22c61503f..3a4307bc1d61 100644
--- a/drivers/net/can/flexcan/flexcan-core.c
+++ b/drivers/net/can/flexcan/flexcan-core.c
@@ -2211,7 +2211,7 @@ static int flexcan_probe(struct platform_device *pdev)
priv->transceiver = transceiver;
if (transceiver)
- priv->can.bitrate_max = transceiver->attrs.max_link_rate;
+ priv->can.bitrate_max = phy_get_max_link_rate(transceiver);
if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_IRQ_3) {
priv->irq_boff = platform_get_irq(pdev, 1);
diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
index 56da411878af..73525be6566b 100644
--- a/drivers/net/can/m_can/m_can_platform.c
+++ b/drivers/net/can/m_can/m_can_platform.c
@@ -132,7 +132,7 @@ static int m_can_plat_probe(struct platform_device *pdev)
}
if (transceiver)
- mcan_class->can.bitrate_max = transceiver->attrs.max_link_rate;
+ mcan_class->can.bitrate_max = phy_get_max_link_rate(transceiver);
priv->base = addr;
priv->mram_base = mram_addr;
diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index eaf8cac78038..645d5671705d 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -1885,7 +1885,7 @@ static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch,
priv->channel = ch;
priv->gpriv = gpriv;
if (transceiver)
- priv->can.bitrate_max = transceiver->attrs.max_link_rate;
+ priv->can.bitrate_max = phy_get_max_link_rate(transceiver);
priv->can.clock.freq = fcan_freq;
dev_info(dev, "can_clk rate is %u\n", priv->can.clock.freq);
diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index a1aff00fba7c..89f7410241aa 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -640,6 +640,12 @@ void phy_set_bus_width(struct phy *phy, int bus_width)
}
EXPORT_SYMBOL_GPL(phy_set_bus_width);
+u32 phy_get_max_link_rate(struct phy *phy)
+{
+ return phy->attrs.max_link_rate;
+}
+EXPORT_SYMBOL_GPL(phy_get_max_link_rate);
+
/**
* _of_phy_get() - lookup and obtain a reference to a phy by phandle
* @np: device_node for which to get the phy
diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index 36307e47760d..af9c3e795786 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h
@@ -57,6 +57,7 @@ int phy_notify_disconnect(struct phy *phy, int port);
int phy_notify_state(struct phy *phy, union phy_notify state);
int phy_get_bus_width(struct phy *phy);
void phy_set_bus_width(struct phy *phy, int bus_width);
+u32 phy_get_max_link_rate(struct phy *phy);
#else
static inline struct phy *phy_get(struct device *dev, const char *string)
{
@@ -256,6 +257,11 @@ static inline int phy_get_bus_width(struct phy *phy)
static inline void phy_set_bus_width(struct phy *phy, int bus_width)
{
}
+
+static inline u32 phy_get_max_link_rate(struct phy *phy)
+{
+ return 0;
+}
#endif /* IS_ENABLED(CONFIG_GENERIC_PHY) */
#endif /* __PHY_CONSUMER_H */
--
2.43.0