Re: [PATCH 2/2] mmc: sdhci-pci-gli: GL9767: Fix initializing the UHS-II interface during a power-on

[Adrian Hunter <adrian.hunter@intel.com>]

On 01/09/2025 12:42, Ben Chuang wrote:
> From: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> 
> According to the power structure of IC hardware design for UHS-II
> interface, reset control and timing must be added to the initialization
> process of powering on the UHS-II interface.
> 
> Fixes: 27dd3b82557a ("mmc: sdhci-pci-gli: enable UHS-II mode for GL9767")
> Cc: stable@vger.kernel.org # v6.13+
> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> ---
>  drivers/mmc/host/sdhci-pci-gli.c | 71 +++++++++++++++++++++++++++++++-
>  1 file changed, 70 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c
> index 3a1de477e9af..85d0d7e6169c 100644
> --- a/drivers/mmc/host/sdhci-pci-gli.c
> +++ b/drivers/mmc/host/sdhci-pci-gli.c
> @@ -283,6 +283,8 @@
>  #define   PCIE_GLI_9767_UHS2_CTL2_ZC_VALUE	  0xb
>  #define   PCIE_GLI_9767_UHS2_CTL2_ZC_CTL	  BIT(6)
>  #define   PCIE_GLI_9767_UHS2_CTL2_ZC_CTL_VALUE	  0x1
> +#define   PCIE_GLI_9767_UHS2_CTL2_FORCE_PHY_RESETN	BIT(13)
> +#define   PCIE_GLI_9767_UHS2_CTL2_FORCE_RESETN_VALUE	BIT(14)
>  
>  #define GLI_MAX_TUNING_LOOP 40
>  
> @@ -1179,6 +1181,69 @@ static void gl9767_set_low_power_negotiation(struct pci_dev *pdev, bool enable)
>  	gl9767_vhs_read(pdev);
>  }
>  
> +static void sdhci_gl9767_uhs2_phy_reset_assert(struct sdhci_host *host)
> +{
> +	struct sdhci_pci_slot *slot = sdhci_priv(host);
> +	struct pci_dev *pdev = slot->chip->pdev;
> +	u32 value;
> +
> +	gl9767_vhs_write(pdev);
> +	pci_read_config_dword(pdev, PCIE_GLI_9767_UHS2_CTL2, &value);
> +	value |= PCIE_GLI_9767_UHS2_CTL2_FORCE_PHY_RESETN;
> +	pci_write_config_dword(pdev, PCIE_GLI_9767_UHS2_CTL2, value);
> +	value &= ~PCIE_GLI_9767_UHS2_CTL2_FORCE_RESETN_VALUE;
> +	pci_write_config_dword(pdev, PCIE_GLI_9767_UHS2_CTL2, value);
> +	gl9767_vhs_read(pdev);
> +}
> +
> +static void sdhci_gl9767_uhs2_phy_reset_deassert(struct sdhci_host *host)
> +{
> +	struct sdhci_pci_slot *slot = sdhci_priv(host);
> +	struct pci_dev *pdev = slot->chip->pdev;
> +	u32 value;
> +
> +	gl9767_vhs_write(pdev);
> +	pci_read_config_dword(pdev, PCIE_GLI_9767_UHS2_CTL2, &value);
> +	value |= PCIE_GLI_9767_UHS2_CTL2_FORCE_RESETN_VALUE;

Maybe add a small comment about PCIE_GLI_9767_UHS2_CTL2_FORCE_RESETN_VALUE
and PCIE_GLI_9767_UHS2_CTL2_FORCE_PHY_RESETN being updated separately.

> +	pci_write_config_dword(pdev, PCIE_GLI_9767_UHS2_CTL2, value);
> +	value &= ~PCIE_GLI_9767_UHS2_CTL2_FORCE_PHY_RESETN;
> +	pci_write_config_dword(pdev, PCIE_GLI_9767_UHS2_CTL2, value);
> +	gl9767_vhs_read(pdev);
> +}

sdhci_gl9767_uhs2_phy_reset_assert() and sdhci_gl9767_uhs2_phy_reset_deassert()
are fairly similar.  Maybe consider:

static void sdhci_gl9767_uhs2_phy_reset(struct sdhci_host *host, bool assert)
{
	struct sdhci_pci_slot *slot = sdhci_priv(host);
	struct pci_dev *pdev = slot->chip->pdev;
	u32 value, set, clr;

	if (assert) {
		set = PCIE_GLI_9767_UHS2_CTL2_FORCE_PHY_RESETN;
		clr = PCIE_GLI_9767_UHS2_CTL2_FORCE_RESETN_VALUE;
	} else {
		set = PCIE_GLI_9767_UHS2_CTL2_FORCE_RESETN_VALUE;
		clr = PCIE_GLI_9767_UHS2_CTL2_FORCE_PHY_RESETN;
	}

	gl9767_vhs_write(pdev);
	pci_read_config_dword(pdev, PCIE_GLI_9767_UHS2_CTL2, &value);
	value |= set;
	pci_write_config_dword(pdev, PCIE_GLI_9767_UHS2_CTL2, value);
	value &= ~clr;
	pci_write_config_dword(pdev, PCIE_GLI_9767_UHS2_CTL2, value);
	gl9767_vhs_read(pdev);
}


> +
> +static void __gl9767_uhs2_set_power(struct sdhci_host *host, unsigned char mode, unsigned short vdd)
> +{
> +	u8 pwr = 0;
> +
> +	if (mode != MMC_POWER_OFF) {
> +		pwr = sdhci_get_vdd_value(vdd);
> +		if (!pwr)
> +			WARN(1, "%s: Invalid vdd %#x\n",
> +			     mmc_hostname(host->mmc), vdd);
> +		pwr |= SDHCI_VDD2_POWER_180;
> +	}
> +
> +	if (host->pwr == pwr)
> +		return;
> +
> +	host->pwr = pwr;
> +
> +	if (pwr == 0) {
> +		sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
> +	} else {
> +		sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
> +
> +		pwr |= SDHCI_POWER_ON;
> +		sdhci_writeb(host, pwr & 0xf, SDHCI_POWER_CONTROL);
> +		mdelay(5);

Can be mmc_delay(5)

> +
> +		sdhci_gl9767_uhs2_phy_reset_assert(host);
> +		pwr |= SDHCI_VDD2_POWER_ON;
> +		sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
> +		mdelay(5);

Can be mmc_delay(5)

> +	}
> +}
> +
>  static void sdhci_gl9767_set_clock(struct sdhci_host *host, unsigned int clock)
>  {
>  	struct sdhci_pci_slot *slot = sdhci_priv(host);
> @@ -1205,6 +1270,10 @@ static void sdhci_gl9767_set_clock(struct sdhci_host *host, unsigned int clock)
>  	}
>  
>  	sdhci_enable_clk(host, clk);
> +
> +	if (mmc_card_uhs2(host->mmc))
> +		sdhci_gl9767_uhs2_phy_reset_deassert(host);
> +
>  	gl9767_set_low_power_negotiation(pdev, true);
>  }
>  
> @@ -1476,7 +1545,7 @@ static void sdhci_gl9767_set_power(struct sdhci_host *host, unsigned char mode,
>  		gl9767_vhs_read(pdev);
>  
>  		sdhci_gli_overcurrent_event_enable(host, false);
> -		sdhci_uhs2_set_power(host, mode, vdd);
> +		__gl9767_uhs2_set_power(host, mode, vdd);
>  		sdhci_gli_overcurrent_event_enable(host, true);
>  	} else {
>  		gl9767_vhs_write(pdev);