[PATCH net-next v3 06/10] net: macb: add mpfs specific usrio configuration

Conor Dooley
2026-03-10T17:19:28Z

On mpfs the driver needs to make sure the tsu clock source is not the
fabric, as this requires that the hardware is in Timer Adjust mode,
which is not compatible with the linux driver trying to control the
hardware. It is unlikely that this will be set, as the peripheral is
reset during probe, but if the resets are not provided in devicetree
it's probable that this bit is set incorrectly, as U-Boot's macb driver
has the same issue with using usrio settings for at91 platforms as the
default.

Fixes: 8aad66aa59be5 ("net: macb: add polarfire soc reset support")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
drivers/net/ethernet/cadence/macb.h | 2 ++
drivers/net/ethernet/cadence/macb_main.c | 12 ++++++++++--
2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 9cd565cb87e4c..cdb9fb2218c6f 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -781,6 +781,7 @@
#define MACB_CAPS_NO_LSO BIT(24)
#define MACB_CAPS_USRIO_HAS_MII BIT(25)
#define MACB_CAPS_USRIO_HAS_REFCLK_SOURCE BIT(26)
+#define MACB_CAPS_USRIO_HAS_TSUCLK_SOURCE BIT(27)

/* LSO settings */
#define MACB_LSO_UFO_ENABLE 0x01
@@ -1214,6 +1215,7 @@ struct macb_usrio_config {
u32 refclk;
u32 clken;
u32 hdfctlen;
+ u32 tsu_source;
bool refclk_default_external;
};

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 414a8fa3f99d9..b476bc9663ecd 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -4650,6 +4650,9 @@ static int macb_init(struct platform_device *pdev)
val |= bp->usrio->refclk;
}

+ if (bp->caps & MACB_CAPS_USRIO_HAS_TSUCLK_SOURCE)
+ val |= bp->usrio->tsu_source;
+
macb_or_gem_writel(bp, USRIO, val);
}

@@ -5244,6 +5247,10 @@ static const struct macb_usrio_config at91_default_usrio = {
.clken = MACB_BIT(CLKEN),
};

+static const struct macb_usrio_config mpfs_usrio = {
+ .tsu_source = 0,
+};
+
static const struct macb_usrio_config sama7g5_gem_usrio = {
.mii = 0,
.rmii = 1,
@@ -5376,11 +5383,12 @@ static const struct macb_config zynq_config = {
static const struct macb_config mpfs_config = {
.caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE |
MACB_CAPS_JUMBO |
- MACB_CAPS_GEM_HAS_PTP,
+ MACB_CAPS_GEM_HAS_PTP |
+ MACB_CAPS_USRIO_HAS_TSUCLK_SOURCE,
.dma_burst_length = 16,
.clk_init = macb_clk_init,
.init = init_reset_optional,
- .usrio = &at91_default_usrio,
+ .usrio = &mpfs_usrio,
.max_tx_length = 4040, /* Cadence Erratum 1686 */
.jumbo_max_len = 4040,
};