Re: [PATCH V5 18/26] mmc: sdhci-uhs2: add uhs2_control() to initialise the interface

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

On 19/10/22 14:06, Victor Shih wrote:
> This is a sdhci version of mmc's uhs2_set_reg operation.
> UHS-II interface (related registers) will be initialised here.
> 
> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
> ---
>  drivers/mmc/host/sdhci-uhs2.c | 103 ++++++++++++++++++++++++++++++++++
>  drivers/mmc/host/sdhci.c      |  12 ++++
>  drivers/mmc/host/sdhci.h      |   1 +
>  3 files changed, 116 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index afaca5d96938..c9d59b8ac37f 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -350,6 +350,53 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  	spin_unlock_irqrestore(&host->lock, flags);
>  }
>  
> +static void sdhci_uhs2_set_config(struct sdhci_host *host)
> +{
> +	u32 value;
> +	u16 sdhci_uhs2_set_ptr = sdhci_readw(host, SDHCI_UHS2_SET_PTR);
> +	u16 sdhci_uhs2_gen_set_reg = (sdhci_uhs2_set_ptr + 0);
> +	u16 sdhci_uhs2_phy_set_reg = (sdhci_uhs2_set_ptr + 4);
> +	u16 sdhci_uhs2_tran_set_reg = (sdhci_uhs2_set_ptr + 8);
> +	u16 sdhci_uhs2_tran_set_1_reg = (sdhci_uhs2_set_ptr + 12);
> +
> +	/* Set Gen Settings */
> +	sdhci_writel(host, host->mmc->uhs2_caps.n_lanes_set <<
> +		SDHCI_UHS2_GEN_SET_N_LANES_POS, sdhci_uhs2_gen_set_reg);
> +
> +	/* Set PHY Settings */
> +	value = (host->mmc->uhs2_caps.n_lss_dir_set <<
> +			SDHCI_UHS2_PHY_SET_N_LSS_DIR_POS) |
> +		(host->mmc->uhs2_caps.n_lss_sync_set <<
> +			SDHCI_UHS2_PHY_SET_N_LSS_SYN_POS);
> +	if (host->mmc->flags & MMC_UHS2_SPEED_B)
> +		value |= 1 << SDHCI_UHS2_PHY_SET_SPEED_POS;
> +	sdhci_writel(host, value, sdhci_uhs2_phy_set_reg);
> +
> +	/* Set LINK-TRAN Settings */
> +	value = (host->mmc->uhs2_caps.max_retry_set <<
> +			SDHCI_UHS2_TRAN_SET_RETRY_CNT_POS) |
> +		(host->mmc->uhs2_caps.n_fcu_set <<
> +			SDHCI_UHS2_TRAN_SET_N_FCU_POS);
> +	sdhci_writel(host, value, sdhci_uhs2_tran_set_reg);
> +	sdhci_writel(host, host->mmc->uhs2_caps.n_data_gap_set,
> +		     sdhci_uhs2_tran_set_1_reg);
> +}
> +
> +static int sdhci_uhs2_check_dormant(struct sdhci_host *host)
> +{
> +	u32 val;
> +	/* 100ms */
> +	int timeout = 100000;
> +
> +	if (read_poll_timeout_atomic(sdhci_readl, val, (val & SDHCI_UHS2_IN_DORMANT_STATE),
> +				     100, timeout, true, host, SDHCI_PRESENT_STATE)) {
> +		pr_warn("%s: UHS2 IN_DORMANT fail in 100ms.\n", mmc_hostname(host->mmc));
> +		sdhci_dumpregs(host);
> +		return -EIO;
> +	}
> +	return 0;
> +}
> +
>  /*****************************************************************************\
>   *                                                                           *
>   * MMC callbacks                                                             *
> @@ -435,6 +482,61 @@ static int sdhci_uhs2_enable_clk(struct mmc_host *mmc)
>  	return 0;
>  }
>  
> +static int sdhci_uhs2_do_detect_init(struct mmc_host *mmc);
> +
> +static int sdhci_uhs2_control(struct mmc_host *mmc, enum sd_uhs2_operation op)
> +{
> +	struct sdhci_host *host = mmc_priv(mmc);
> +	unsigned long flags;
> +	int err = 0;
> +	u16 sdhci_uhs2_set_ptr = sdhci_readw(host, SDHCI_UHS2_SET_PTR);
> +	u16 sdhci_uhs2_phy_set_reg = (sdhci_uhs2_set_ptr + 4);
> +
> +	DBG("Begin %s, act %d.\n", __func__, op);

DBG already has __func__.  Please also check other DBG that
have duplicate __func__

> +
> +	spin_lock_irqsave(&host->lock, flags);

This all relates to initialization or reinitialization, so I suspect
the spinlock is not needed here.  What could it be racing with?

> +
> +	switch (op) {
> +	case UHS2_PHY_INIT:
> +		err = sdhci_uhs2_do_detect_init(mmc);
> +		break;
> +	case UHS2_SET_CONFIG:
> +		sdhci_uhs2_set_config(host);
> +		break;
> +	case UHS2_ENABLE_INT:
> +		sdhci_clear_set_irqs(host, 0, SDHCI_INT_CARD_INT);
> +		break;
> +	case UHS2_DISABLE_INT:
> +		sdhci_clear_set_irqs(host, SDHCI_INT_CARD_INT, 0);
> +		break;
> +	case UHS2_SET_SPEED_B:
> +		sdhci_writeb(host, 1 << SDHCI_UHS2_PHY_SET_SPEED_POS,
> +			     sdhci_uhs2_phy_set_reg);
> +		break;
> +	case UHS2_CHECK_DORMANT:
> +		err = sdhci_uhs2_check_dormant(host);
> +		break;
> +	case UHS2_DISABLE_CLK:
> +		err = sdhci_uhs2_disable_clk(mmc);
> +		break;
> +	case UHS2_ENABLE_CLK:
> +		err = sdhci_uhs2_enable_clk(mmc);
> +		break;
> +	case UHS2_POST_ATTACH_SD:
> +		host->ops->uhs2_post_attach_sd(host);
> +		break;
> +	default:
> +		pr_err("%s: input sd uhs2 operation %d is wrong!\n",
> +		       mmc_hostname(host->mmc), op);
> +		err = -EIO;
> +		break;
> +	}
> +
> +	spin_unlock_irqrestore(&host->lock, flags);
> +
> +	return err;
> +}
> +
>  /*****************************************************************************\
>   *                                                                           *
>   * Driver init/exit                                                          *
> @@ -589,6 +691,7 @@ 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.uhs2_set_ios = sdhci_uhs2_set_ios;
> +	host->mmc_host_ops.uhs2_control = sdhci_uhs2_control;
>  
>  	if (!host->mmc_host_ops.uhs2_detect_init)
>  		host->mmc_host_ops.uhs2_detect_init = sdhci_uhs2_do_detect_init;
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index de47c71995fb..b9db2e976010 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -236,6 +236,18 @@ void sdhci_reset(struct sdhci_host *host, u8 mask)
>  }
>  EXPORT_SYMBOL_GPL(sdhci_reset);
>  
> +void sdhci_clear_set_irqs(struct sdhci_host *host, u32 clear, u32 set)
> +{
> +	u32 ier;
> +
> +	ier = sdhci_readl(host, SDHCI_INT_ENABLE);
> +	ier &= ~clear;
> +	ier |= set;
> +	sdhci_writel(host, ier, SDHCI_INT_ENABLE);
> +	sdhci_writel(host, ier, SDHCI_SIGNAL_ENABLE);
> +}
> +EXPORT_SYMBOL_GPL(sdhci_clear_set_irqs);

This might as well be in sdhci-uhs2.c since that is the only
place that calls it.  Then there is no need to export it.

> +
>  static bool sdhci_do_reset(struct sdhci_host *host, u8 mask)
>  {
>  	if (host->quirks & SDHCI_QUIRK_NO_CARD_NO_RESET) {
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 22d7f47862ae..f049331bd0bc 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -869,6 +869,7 @@ void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq);
>  int sdhci_request_atomic(struct mmc_host *mmc, struct mmc_request *mrq);
>  void sdhci_set_bus_width(struct sdhci_host *host, int width);
>  void sdhci_reset(struct sdhci_host *host, u8 mask);
> +void sdhci_clear_set_irqs(struct sdhci_host *host, u32 clear, u32 set);
>  void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing);
>  int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode);
>  void sdhci_enable_preset_value(struct sdhci_host *host, bool enable);