[PATCH net-next v2 2/5] net: mediatek: sgmii: ensure the SGMII PHY is powered down on configuration

From: Alexander Couzens
Date: Mon Sep 19 2022 - 04:48:56 EST


The code expect the PHY to be in power down which is only true after reset.
Allow changes of the SGMII parameters more than once.

Signed-off-by: Alexander Couzens <lynxis@xxxxxxx>
---
drivers/net/ethernet/mediatek/mtk_sgmii.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_sgmii.c b/drivers/net/ethernet/mediatek/mtk_sgmii.c
index b9b15e1a292c..18de85709e87 100644
--- a/drivers/net/ethernet/mediatek/mtk_sgmii.c
+++ b/drivers/net/ethernet/mediatek/mtk_sgmii.c
@@ -7,6 +7,7 @@
*
*/

+#include <linux/delay.h>
#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/phylink.h>
@@ -24,6 +25,9 @@ static int mtk_pcs_setup_mode_an(struct mtk_pcs *mpcs)
{
unsigned int val;

+ /* PHYA power down */
+ regmap_write(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL, SGMII_PHYA_PWD);
+
/* Setup the link timer and QPHY power up inside SGMIISYS */
regmap_write(mpcs->regmap, SGMSYS_PCS_LINK_TIMER,
SGMII_LINK_TIMER_DEFAULT);
@@ -42,8 +46,10 @@ static int mtk_pcs_setup_mode_an(struct mtk_pcs *mpcs)
* prevents SGMII from working. The SGMII still shows link but no traffic
* can flow. Writing 0x0 to the PHYA_PWD register fix the issue. 0x0 was
* taken from a good working state of the SGMII interface.
+ * Unknown how much the QPHY needs but it is racy without a sleep.
* Tested on mt7622 & mt7986.
*/
+ usleep_range(50, 100);
regmap_write(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL, 0);

return 0;
@@ -58,6 +64,9 @@ static int mtk_pcs_setup_mode_force(struct mtk_pcs *mpcs,
{
unsigned int val;

+ /* PHYA power down */
+ regmap_write(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL, SGMII_PHYA_PWD);
+
regmap_read(mpcs->regmap, mpcs->ana_rgc3, &val);
val &= ~RG_PHY_SPEED_MASK;
if (interface == PHY_INTERFACE_MODE_2500BASEX)
@@ -81,8 +90,10 @@ static int mtk_pcs_setup_mode_force(struct mtk_pcs *mpcs,
* prevents SGMII from working. The SGMII still shows link but no traffic
* can flow. Writing 0x0 to the PHYA_PWD register fix the issue. 0x0 was
* taken from a good working state of the SGMII interface.
+ * Unknown how much the QPHY needs but it is racy without a sleep.
* Tested on mt7622 & mt7986.
*/
+ usleep_range(50, 100);
regmap_write(mpcs->regmap, SGMSYS_QPHY_PWR_STATE_CTRL, 0);

return 0;
--
2.37.3