Re: [PATCH v2] net: phy: air_en8811h: add AN8811HB MCU assert/deassert support

["Lucien.Jheng" <lucienzx159@gmail.com>]

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.
>> 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@gmail.com>
>> ---
>> 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;
>> +}
>> +
> Maybe you can use mutex_lock() and mutex_unlock() here also, like so:
>
> 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
>
Thank you for your feedback.

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
>>