Re: [RFC PATCH v3.1 17/27] mmc: sdhci-uhs2: add detect_init() to detect the interface

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

On Thu, Nov 26, 2020 at 10:17:38AM +0200, Adrian Hunter wrote:
> On 6/11/20 4:27 am, AKASHI Takahiro wrote:
> > Sdhci_uhs2_do_detect_init() is a sdhci version of mmc's uhs2_detect_init
> > operation. After detected, the host's UHS-II capabilities will be set up
> > here and interrupts will also be enabled.
> > 
> > Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > ---
> >  drivers/mmc/host/sdhci-uhs2.c | 160 ++++++++++++++++++++++++++++++++++
> >  1 file changed, 160 insertions(+)
> > 
> > diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> > index 637464748cc4..994dff967e85 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.c
> > +++ b/drivers/mmc/host/sdhci-uhs2.c
> > @@ -391,12 +391,172 @@ void sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> >   *                                                                           *
> >  \*****************************************************************************/
> >  
> > +static int sdhci_uhs2_interface_detect(struct sdhci_host *host)
> > +{
> > +	int timeout = 100;
> 
> Please comment on where timeouts / delays come from. e.g. as per spec

It does exist in the original code, but I will try to find the source
of information.

> > +
> > +	udelay(200); /* wait for 200us before check */
> > +
> > +	while (!(sdhci_readl(host, SDHCI_PRESENT_STATE) &
> > +		SDHCI_UHS2_IF_DETECT)) {
> 
> 
> Can be read_poll_timeout(sdhci_readl,...,host, SDHCI_PRESENT_STATE)

Okay.

> > +		if (timeout == 0) {
> > +			pr_warn("%s: not detect UHS2 interface in 200us.\n",
> > +				mmc_hostname(host->mmc));
> > +			sdhci_dumpregs(host);
> > +			return -EIO;
> > +		}
> > +		timeout--;
> > +		mdelay(1);
> > +	}
> > +
> > +	/* Enable UHS2 error interrupts */
> > +	sdhci_uhs2_clear_set_irqs(host, SDHCI_INT_ALL_MASK,
> > +				  SDHCI_UHS2_ERR_INT_STATUS_MASK);
> > +
> > +	timeout = 150;
> > +	while (!(sdhci_readl(host, SDHCI_PRESENT_STATE) &
> > +		SDHCI_UHS2_LANE_SYNC)) {
> 
> Ditto

Okay.

-Takahiro Akashi

> 
> > +		if (timeout == 0) {
> > +			pr_warn("%s: UHS2 Lane sync fail in 150ms.\n",
> > +				mmc_hostname(host->mmc));
> > +			sdhci_dumpregs(host);
> > +			return -EIO;
> > +		}
> > +		timeout--;
> > +		mdelay(1);
> > +	}
> > +
> > +	DBG("%s: UHS2 Lane synchronized in UHS2 mode, PHY is initialized.\n",
> > +	    mmc_hostname(host->mmc));
> > +	return 0;
> > +}
> > +
> > +static int sdhci_uhs2_init(struct sdhci_host *host)
> > +{
> > +	u16 caps_ptr = 0;
> > +	u32 caps_gen = 0;
> > +	u32 caps_phy = 0;
> > +	u32 caps_tran[2] = {0, 0};
> > +	struct mmc_host *mmc = host->mmc;
> > +
> > +	/*
> > +	 * TODO: may add corresponding members in sdhci_host to
> > +	 * keep these caps.
> > +	 */
> > +	caps_ptr = sdhci_readw(host, SDHCI_UHS2_HOST_CAPS_PTR);
> > +	if (caps_ptr < 0x100 || caps_ptr > 0x1FF) {
> > +		pr_err("%s: SDHCI_UHS2_HOST_CAPS_PTR(%d) is wrong.\n",
> > +		       mmc_hostname(mmc), caps_ptr);
> > +		return -ENODEV;
> > +	}
> > +	caps_gen = sdhci_readl(host,
> > +			       caps_ptr + SDHCI_UHS2_HOST_CAPS_GEN_OFFSET);
> > +	caps_phy = sdhci_readl(host,
> > +			       caps_ptr + SDHCI_UHS2_HOST_CAPS_PHY_OFFSET);
> > +	caps_tran[0] = sdhci_readl(host,
> > +				   caps_ptr + SDHCI_UHS2_HOST_CAPS_TRAN_OFFSET);
> > +	caps_tran[1] = sdhci_readl(host,
> > +				   caps_ptr
> > +					+ SDHCI_UHS2_HOST_CAPS_TRAN_1_OFFSET);
> > +
> > +	/* General Caps */
> > +	mmc->uhs2_caps.dap = caps_gen & SDHCI_UHS2_HOST_CAPS_GEN_DAP_MASK;
> > +	mmc->uhs2_caps.gap = (caps_gen & SDHCI_UHS2_HOST_CAPS_GEN_GAP_MASK) >>
> > +			     SDHCI_UHS2_HOST_CAPS_GEN_GAP_SHIFT;
> > +	mmc->uhs2_caps.n_lanes = (caps_gen & SDHCI_UHS2_HOST_CAPS_GEN_LANE_MASK)
> > +			>> SDHCI_UHS2_HOST_CAPS_GEN_LANE_SHIFT;
> > +	mmc->uhs2_caps.addr64 =
> > +		(caps_gen & SDHCI_UHS2_HOST_CAPS_GEN_ADDR_64) ? 1 : 0;
> > +	mmc->uhs2_caps.card_type =
> > +		(caps_gen & SDHCI_UHS2_HOST_CAPS_GEN_DEV_TYPE_MASK) >>
> > +		SDHCI_UHS2_HOST_CAPS_GEN_DEV_TYPE_SHIFT;
> > +
> > +	/* PHY Caps */
> > +	mmc->uhs2_caps.phy_rev = caps_phy & SDHCI_UHS2_HOST_CAPS_PHY_REV_MASK;
> > +	mmc->uhs2_caps.speed_range =
> > +		(caps_phy & SDHCI_UHS2_HOST_CAPS_PHY_RANGE_MASK)
> > +		>> SDHCI_UHS2_HOST_CAPS_PHY_RANGE_SHIFT;
> > +	mmc->uhs2_caps.n_lss_sync =
> > +		(caps_phy & SDHCI_UHS2_HOST_CAPS_PHY_N_LSS_SYN_MASK)
> > +		>> SDHCI_UHS2_HOST_CAPS_PHY_N_LSS_SYN_SHIFT;
> > +	mmc->uhs2_caps.n_lss_dir =
> > +		(caps_phy & SDHCI_UHS2_HOST_CAPS_PHY_N_LSS_DIR_MASK)
> > +		>> SDHCI_UHS2_HOST_CAPS_PHY_N_LSS_DIR_SHIFT;
> > +	if (mmc->uhs2_caps.n_lss_sync == 0)
> > +		mmc->uhs2_caps.n_lss_sync = 16 << 2;
> > +	else
> > +		mmc->uhs2_caps.n_lss_sync <<= 2;
> > +	if (mmc->uhs2_caps.n_lss_dir == 0)
> > +		mmc->uhs2_caps.n_lss_dir = 16 << 3;
> > +	else
> > +		mmc->uhs2_caps.n_lss_dir <<= 3;
> > +
> > +	/* LINK/TRAN Caps */
> > +	mmc->uhs2_caps.link_rev =
> > +		caps_tran[0] & SDHCI_UHS2_HOST_CAPS_TRAN_LINK_REV_MASK;
> > +	mmc->uhs2_caps.n_fcu =
> > +		(caps_tran[0] & SDHCI_UHS2_HOST_CAPS_TRAN_N_FCU_MASK)
> > +		>> SDHCI_UHS2_HOST_CAPS_TRAN_N_FCU_SHIFT;
> > +	if (mmc->uhs2_caps.n_fcu == 0)
> > +		mmc->uhs2_caps.n_fcu = 256;
> > +	mmc->uhs2_caps.host_type =
> > +		(caps_tran[0] & SDHCI_UHS2_HOST_CAPS_TRAN_HOST_TYPE_MASK)
> > +		>> SDHCI_UHS2_HOST_CAPS_TRAN_HOST_TYPE_SHIFT;
> > +	mmc->uhs2_caps.maxblk_len =
> > +		(caps_tran[0] & SDHCI_UHS2_HOST_CAPS_TRAN_BLK_LEN_MASK)
> > +		>> SDHCI_UHS2_HOST_CAPS_TRAN_BLK_LEN_SHIFT;
> > +	mmc->uhs2_caps.n_data_gap =
> > +		caps_tran[1] & SDHCI_UHS2_HOST_CAPS_TRAN_1_N_DATA_GAP_MASK;
> > +
> > +	return 0;
> > +}
> > +
> > +static int sdhci_uhs2_do_detect_init(struct mmc_host *mmc)
> > +{
> > +        struct sdhci_host *host = mmc_priv(mmc);
> > +	unsigned long flags;
> > +	int ret = -EIO;
> > +
> > +	DBG("%s: begin UHS2 init.\n", __func__);
> > +	spin_lock_irqsave(&host->lock, flags);
> > +
> > +	if (sdhci_uhs2_interface_detect(host)) {
> > +		pr_warn("%s: cannot detect UHS2 interface.\n",
> > +			mmc_hostname(host->mmc));
> > +		goto out;
> > +	}
> > +
> > +	if (sdhci_uhs2_init(host)) {
> > +		pr_warn("%s: UHS2 init fail.\n", mmc_hostname(host->mmc));
> > +		goto out;
> > +	}
> > +
> > +	/* Init complete, do soft reset and enable UHS2 error irqs. */
> > +	sdhci_uhs2_reset(host, SDHCI_UHS2_SW_RESET_SD);
> > +	sdhci_uhs2_clear_set_irqs(host, SDHCI_INT_ALL_MASK,
> > +				  SDHCI_UHS2_ERR_INT_STATUS_MASK);
> > +	/*
> > +	 * !!! SDHCI_INT_ENABLE and SDHCI_SIGNAL_ENABLE was cleared
> > +	 * by SDHCI_UHS2_SW_RESET_SD
> > +	 */
> > +	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
> > +	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
> > +
> > +	ret = 0;
> > +out:
> > +	spin_unlock_irqrestore(&host->lock, flags);
> > +	return ret;
> > +}
> > +
> >  static int sdhci_uhs2_host_ops_init(struct sdhci_host *host)
> >  {
> >  	host->mmc_host_ops.start_signal_voltage_switch =
> >  		sdhci_uhs2_start_signal_voltage_switch;
> >  	host->mmc_host_ops.set_ios = sdhci_uhs2_set_ios;
> >  
> > +	if (!host->mmc_host_ops.uhs2_detect_init)
> > +		host->mmc_host_ops.uhs2_detect_init = sdhci_uhs2_do_detect_init;
> > +
> >  	return 0;
> >  }
> >  
> > 
>