Re: [PATCH v2] net: phy: air_en8811h: add AN8811HB MCU assert/deassert support
From: Lucien.Jheng
Date: Thu Apr 16 2026 - 11:28:16 EST
Hi Eric
Lucien.Jheng 於 2026/3/29 下午 01:04 寫道:
Eric Woudstra 於 2026/3/27 下午 12:41 寫道:
On 3/26/26 4:35 PM, Lucien.Jheng wrote:
AN8811HB needs a MCU soft-reset cycle before firmware loading begins.Maybe you can use mutex_lock() and mutex_unlock() here also, like so:
Assert the MCU (hold it in reset) and immediately deassert (release)
via a dedicated PBUS register pair (0x5cf9f8 / 0x5cf9fc), accessed
through the PHY-addr+8 MDIO bus node rather than the BUCKPBUS indirect
path. This clears the MCU state before the firmware loading sequence
starts.
Add __air_pbus_reg_write() as a low-level helper for this access, then
implement an8811hb_mcu_assert() / _deassert() on top of it. Wire both
into an8811hb_load_firmware() and en8811h_restart_mcu() so every
firmware load or MCU restart on AN8811HB correctly sequences the reset
control registers.
Fixes: 0a55766b7711 ("net: phy: air_en8811h: add Airoha AN8811HB support")
Signed-off-by: Lucien Jheng <lucienzx159@xxxxxxxxx>
---
Changes in v2:
- Rewrite commit message: The previous wording was ambiguous,
as it suggested the MCU remains asserted during the entire
firmware loading process, rather than a quick reset cycle
before it starts.
Clarify that assert and deassert is an immediate soft-reset
cycle to clear MCU state before firmware loading begins.
- Add Fixes: 0a55766b7711 ("net: phy: air_en8811h: add Airoha AN8811HB
support").
- Change phydev_info() to phydev_dbg() in an8811hb_mcu_assert() and
an8811hb_mcu_deassert() to avoid noise during normal boot.
drivers/net/phy/air_en8811h.c | 105 ++++++++++++++++++++++++++++++++++
1 file changed, 105 insertions(+)
diff --git a/drivers/net/phy/air_en8811h.c b/drivers/net/phy/air_en8811h.c
index 29ae73e65caa..01fce1b93618 100644
--- a/drivers/net/phy/air_en8811h.c
+++ b/drivers/net/phy/air_en8811h.c
@@ -170,6 +170,16 @@
#define AN8811HB_CLK_DRV_CKO_LDPWD BIT(13)
#define AN8811HB_CLK_DRV_CKO_LPPWD BIT(14)
+#define AN8811HB_MCU_SW_RST 0x5cf9f8
+#define AN8811HB_MCU_SW_RST_HOLD BIT(16)
+#define AN8811HB_MCU_SW_RST_RUN (BIT(16) | BIT(0))
+#define AN8811HB_MCU_SW_START 0x5cf9fc
+#define AN8811HB_MCU_SW_START_EN BIT(16)
+
+/* MII register constants for PBUS access (PHY addr + 8) */
+#define AIR_PBUS_ADDR_HIGH 0x1c
+#define AIR_PBUS_DATA_HIGH 0x10
+
/* Led definitions */
#define EN8811H_LED_COUNT 3
@@ -254,6 +264,36 @@ static int air_phy_write_page(struct phy_device *phydev, int page)
return __phy_write(phydev, AIR_EXT_PAGE_ACCESS, page);
}
+static int __air_pbus_reg_write(struct phy_device *phydev,
+ u32 pbus_reg, u32 pbus_data)
+{
+ struct mii_bus *bus = phydev->mdio.bus;
+ int pbus_addr = phydev->mdio.addr + 8;
+ int ret;
+
+ ret = __mdiobus_write(bus, pbus_addr, AIR_EXT_PAGE_ACCESS,
+ upper_16_bits(pbus_reg));
+ if (ret < 0)
+ return ret;
+
+ ret = __mdiobus_write(bus, pbus_addr, AIR_PBUS_ADDR_HIGH,
+ (pbus_reg & GENMASK(15, 6)) >> 6);
+ if (ret < 0)
+ return ret;
+
+ ret = __mdiobus_write(bus, pbus_addr, (pbus_reg & GENMASK(5, 2)) >> 2,
+ lower_16_bits(pbus_data));
+ if (ret < 0)
+ return ret;
+
+ ret = __mdiobus_write(bus, pbus_addr, AIR_PBUS_DATA_HIGH,
+ upper_16_bits(pbus_data));
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
After checking, I decided not to implement mutex_lock in pbus_read/write.
This is because these functions are only used within an8811hb_mcu_assert/deassert.
Since these sequences cannot be interrupted, a mutex lock is not required.
Thanks
Thank you for your feedback.
static int __air_pbus_reg_write(struct mdio_device *mdio, u32 pbus_address,
u32 pbus_data)
{
int ret;
ret = __mdiobus_write(mdio->bus, mdio->addr, AIR_EXT_PAGE_ACCESS,
(u16)(pbus_address >> 6));
if (ret < 0)
return ret;
ret = __mdiobus_write(mdio->bus, mdio->addr, (pbus_address >> 2) & 0xf,
(u16)pbus_data);
if (ret < 0)
return ret;
ret = __mdiobus_write(mdio->bus, mdio->addr, AIR_PBUS_DATA_HIGH,
(u16)(pbus_data >> 16));
if (ret < 0)
return ret;
return 0;
}
static int air_pbus_reg_write(struct mdio_device *mdio, u32 pbus_address,
u32 pbus_data)
{
int ret;
mutex_lock(&mdio->bus->mdio_lock);
ret = __air_pbus_reg_write(mdio, pbus_address, pbus_data);
if (ret < 0)
dev_err(&mdio->dev, "%s 0x%08x failed: %d\n", __func__,
pbus_address, ret);
mutex_unlock(&mdio->bus->mdio_lock);
return ret;
}
static int __air_pbus_reg_read(struct mdio_device *mdio, u32 pbus_address,
u32 *pbus_data)
{
int ret, pbus_data_low;
ret = __mdiobus_write(mdio->bus, mdio->addr, AIR_EXT_PAGE_ACCESS,
(u16)(pbus_address >> 6));
if (ret < 0)
return ret;
ret = __mdiobus_read(mdio->bus, mdio->addr, (pbus_address >> 2) & 0xf);
if (ret < 0)
return ret;
pbus_data_low = ret;
ret = __mdiobus_read(mdio->bus, mdio->addr, AIR_PBUS_DATA_HIGH);
if (ret < 0)
return ret;
*pbus_data = (ret << 16) + pbus_data_low;
return 0;
}
static int air_pbus_reg_read(struct mdio_device *mdio, u32 pbus_address,
u32 *pbus_data)
{
int ret;
mutex_lock(&mdio->bus->mdio_lock);
ret = __air_pbus_reg_read(mdio, pbus_address, pbus_data);
if (ret < 0)
dev_err(&mdio->dev, "%s 0x%08x failed: %d\n", __func__,
pbus_address, ret);
mutex_unlock(&mdio->bus->mdio_lock);
return ret;
}
With:
#define AIR_PBUS_DATA_HIGH 0x10
I should add mutex_lock() and mutex_unlock() to protect these operations.
I will include this in the next version.
static int __air_buckpbus_reg_write(struct phy_device *phydev,
u32 pbus_address, u32 pbus_data)
{
@@ -570,10 +610,65 @@ static int an8811hb_load_file(struct phy_device *phydev, const char *name,
return ret;
}
+static int an8811hb_mcu_assert(struct phy_device *phydev)
+{
+ int ret;
+
+ phy_lock_mdio_bus(phydev);
+
+ ret = __air_pbus_reg_write(phydev, AN8811HB_MCU_SW_RST,
+ AN8811HB_MCU_SW_RST_HOLD);
+ if (ret < 0)
+ goto unlock;
+
+ ret = __air_pbus_reg_write(phydev, AN8811HB_MCU_SW_START, 0);
+ if (ret < 0)
+ goto unlock;
+
+ msleep(50);
+ phydev_dbg(phydev, "MCU asserted\n");
+
+unlock:
+ phy_unlock_mdio_bus(phydev);
+ return ret;
+}
+
+static int an8811hb_mcu_deassert(struct phy_device *phydev)
+{
+ int ret;
+
+ phy_lock_mdio_bus(phydev);
+
+ ret = __air_pbus_reg_write(phydev, AN8811HB_MCU_SW_START,
+ AN8811HB_MCU_SW_START_EN);
+ if (ret < 0)
+ goto unlock;
+
+ ret = __air_pbus_reg_write(phydev, AN8811HB_MCU_SW_RST,
+ AN8811HB_MCU_SW_RST_RUN);
+ if (ret < 0)
+ goto unlock;
+
+ msleep(50);
+ phydev_dbg(phydev, "MCU deasserted\n");
+
+unlock:
+ phy_unlock_mdio_bus(phydev);
+ return ret;
+}
+
static int an8811hb_load_firmware(struct phy_device *phydev)
{
int ret;
+ ret = an8811hb_mcu_assert(phydev);
+ if (ret < 0)
+ return ret;
+
+ ret = an8811hb_mcu_deassert(phydev);
+ if (ret < 0)
+ return ret;
+
ret = air_buckpbus_reg_write(phydev, EN8811H_FW_CTRL_1,
EN8811H_FW_CTRL_1_START);
if (ret < 0)
@@ -662,6 +757,16 @@ static int en8811h_restart_mcu(struct phy_device *phydev)
{
int ret;
+ if (phy_id_compare_model(phydev->phy_id, AN8811HB_PHY_ID)) {
+ ret = an8811hb_mcu_assert(phydev);
+ if (ret < 0)
+ return ret;
+
+ ret = an8811hb_mcu_deassert(phydev);
+ if (ret < 0)
+ return ret;
+ }
+
ret = air_buckpbus_reg_write(phydev, EN8811H_FW_CTRL_1,
EN8811H_FW_CTRL_1_START);
if (ret < 0)
--
2.34.1