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Message-ID: <fcd88dd6-4538-cb35-a4e8-750bef1a6c08@intel.com>
Date:   Thu, 5 Jan 2023 23:27:53 +0200
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From:   Adrian Hunter <adrian.hunter@intel.com>
Subject: Re: [PATCH V6 14/24] mmc: sdhci-uhs2: add set_ios()
To:     Victor Shih <victorshihgli@gmail.com>, ulf.hansson@linaro.org
Cc:     linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
        benchuanggli@gmail.com, HL.Liu@genesyslogic.com.tw,
        Greg.tu@genesyslogic.com.tw, takahiro.akashi@linaro.org,
        dlunev@chromium.org, Victor Shih <victor.shih@genesyslogic.com.tw>,
        Ben Chuang <ben.chuang@genesyslogic.com.tw>
References: <20221213090047.3805-1-victor.shih@genesyslogic.com.tw>
 <20221213090047.3805-15-victor.shih@genesyslogic.com.tw>
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In-Reply-To: <20221213090047.3805-15-victor.shih@genesyslogic.com.tw>
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On 13/12/22 11:00, Victor Shih wrote:
> This is a sdhci version of mmc's set_ios operation.
> It covers both UHS-I and UHS-II.
> 
> 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 | 96 +++++++++++++++++++++++++++++++++++
>  drivers/mmc/host/sdhci-uhs2.h |  1 +
>  drivers/mmc/host/sdhci.c      | 53 +++++++++++--------
>  drivers/mmc/host/sdhci.h      |  2 +
>  4 files changed, 131 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index 00b1b69b49ea..3d52d35a91a5 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -213,6 +213,68 @@ void sdhci_uhs2_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
>  }
>  EXPORT_SYMBOL_GPL(sdhci_uhs2_set_timeout);
>  
> +/**
> + * sdhci_uhs2_clear_set_irqs - set Error Interrupt Status Enable register
> + * @host:	SDHCI host
> + * @clear:	bit-wise clear mask
> + * @set:	bit-wise set mask
> + *
> + * Set/unset bits in UHS-II Error Interrupt Status Enable register
> + */
> +void sdhci_uhs2_clear_set_irqs(struct sdhci_host *host, u32 clear, u32 set)
> +{
> +	u32 ier;
> +
> +	ier = sdhci_readl(host, SDHCI_UHS2_INT_STATUS_ENABLE);
> +	ier &= ~clear;
> +	ier |= set;
> +	sdhci_writel(host, ier, SDHCI_UHS2_INT_STATUS_ENABLE);
> +	sdhci_writel(host, ier, SDHCI_UHS2_INT_SIGNAL_ENABLE);
> +}
> +EXPORT_SYMBOL_GPL(sdhci_uhs2_clear_set_irqs);
> +
> +static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> +{
> +	struct sdhci_host *host = mmc_priv(mmc);
> +	u8 cmd_res, dead_lock;
> +	u16 ctrl_2;
> +
> +	/* UHS2 Timeout Control */
> +	sdhci_calc_timeout_uhs2(host, &cmd_res, &dead_lock);
> +
> +	/* change to use calculate value */
> +	cmd_res |= FIELD_PREP(SDHCI_UHS2_TIMER_CTRL_DEADLOCK_MASK, dead_lock);
> +
> +	sdhci_uhs2_clear_set_irqs(host,
> +				  SDHCI_UHS2_INT_CMD_TIMEOUT |
> +				  SDHCI_UHS2_INT_DEADLOCK_TIMEOUT,
> +				  0);
> +	sdhci_writeb(host, cmd_res, SDHCI_UHS2_TIMER_CTRL);
> +	sdhci_uhs2_clear_set_irqs(host, 0,
> +				  SDHCI_UHS2_INT_CMD_TIMEOUT |
> +				  SDHCI_UHS2_INT_DEADLOCK_TIMEOUT);
> +
> +	/* UHS2 timing */

Please extend comment to include:

	Note, UHS2 timing is disabled when powering off

> +	ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> +	if (ios->timing == MMC_TIMING_SD_UHS2)
> +		ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
> +	else
> +		ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);
> +	sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
> +
> +	if (!(host->quirks2 & SDHCI_QUIRK2_PRESET_VALUE_BROKEN))
> +		sdhci_enable_preset_value(host, true);
> +
> +	if (host->ops->set_power)
> +		host->ops->set_power(host, ios->power_mode, ios->vdd);
> +	else
> +		sdhci_uhs2_set_power(host, ios->power_mode, ios->vdd);

sdhci_set_ios_common() already set the power.  Are both needed?

> +	udelay(100);

Please add a comment for why this delay is here.

> +
> +	host->timing = ios->timing;

Please move this up to where the timing change is.

> +	sdhci_set_clock(host, host->clock);
> +}
> +
>  /*****************************************************************************\
>   *                                                                           *
>   * MMC callbacks                                                             *
> @@ -234,6 +296,39 @@ static int sdhci_uhs2_start_signal_voltage_switch(struct mmc_host *mmc,
>  	return sdhci_start_signal_voltage_switch(mmc, ios);
>  }
>  
> +int sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)

Should be static

> +{
> +	struct sdhci_host *host = mmc_priv(mmc);
> +
> +	if (!(host->version >= SDHCI_SPEC_400) ||
> +	    !(host->mmc->flags & MMC_UHS2_SUPPORT &&
> +	      host->mmc->caps2 & MMC_CAP2_SD_UHS2)) {

This can be just:

	if (!sdhci_uhs2_mode(host)) {

Not sure if this is actually possible?

> +		sdhci_set_ios(mmc, ios);
> +		return 0;
> +	}
> +
> +	if (ios->power_mode == MMC_POWER_UNDEFINED)
> +		return 0;
> +
> +	if (host->flags & SDHCI_DEVICE_DEAD) {
> +		if (!IS_ERR(mmc->supply.vmmc) &&
> +		    ios->power_mode == MMC_POWER_OFF)
> +			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
> +		if (!IS_ERR_OR_NULL(mmc->supply.vmmc2) &&
> +		    ios->power_mode == MMC_POWER_OFF)
> +			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc2, 0);

This can be just:

		if (ios->power_mode == MMC_POWER_OFF) {
			mmc_opt_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
			mmc_opt_regulator_set_ocr(mmc, mmc->supply.vmmc2, 0);
		}

> +		return -1;
> +	}
> +
> +	host->timing = ios->timing;

__sdhci_uhs2_set_ios() does this so it is not needed here.

> +
> +	sdhci_set_ios_common(mmc, ios);
> +
> +	__sdhci_uhs2_set_ios(mmc, ios);
> +
> +	return 0;
> +}
> +
>  /*****************************************************************************\
>   *                                                                           *
>   * Driver init/exit                                                          *
> @@ -244,6 +339,7 @@ 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;
>  
>  	return 0;
>  }
> diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
> index a58ef19c08aa..184fee80253c 100644
> --- a/drivers/mmc/host/sdhci-uhs2.h
> +++ b/drivers/mmc/host/sdhci-uhs2.h
> @@ -178,5 +178,6 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host);
>  bool sdhci_uhs2_mode(struct sdhci_host *host);
>  void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);
>  void sdhci_uhs2_set_timeout(struct sdhci_host *host, struct mmc_command *cmd);
> +void sdhci_uhs2_clear_set_irqs(struct sdhci_host *host, u32 clear, u32 set);
>  
>  #endif /* __SDHCI_UHS2_H */
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 99633a3ef549..49bbdc155b2b 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -47,8 +47,6 @@
>  static unsigned int debug_quirks = 0;
>  static unsigned int debug_quirks2;
>  
> -static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable);
> -
>  static bool sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd);
>  
>  void sdhci_dumpregs(struct sdhci_host *host)
> @@ -1877,6 +1875,9 @@ static u16 sdhci_get_preset_value(struct sdhci_host *host)
>  	case MMC_TIMING_MMC_HS400:
>  		preset = sdhci_readw(host, SDHCI_PRESET_FOR_HS400);
>  		break;
> +	case MMC_TIMING_SD_UHS2:
> +		preset = sdhci_readw(host, SDHCI_PRESET_FOR_UHS2);
> +		break;
>  	default:
>  		pr_warn("%s: Invalid UHS-I mode selected\n",
>  			mmc_hostname(host->mmc));
> @@ -2325,24 +2326,9 @@ static bool sdhci_presetable_values_change(struct sdhci_host *host, struct mmc_i
>  	       (sdhci_preset_needed(host, ios->timing) || host->drv_type != ios->drv_type);
>  }
>  
> -void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> +void sdhci_set_ios_common(struct mmc_host *mmc, struct mmc_ios *ios)
>  {
>  	struct sdhci_host *host = mmc_priv(mmc);
> -	bool reinit_uhs = host->reinit_uhs;
> -	bool turning_on_clk = false;
> -	u8 ctrl;
> -
> -	host->reinit_uhs = false;
> -
> -	if (ios->power_mode == MMC_POWER_UNDEFINED)
> -		return;
> -
> -	if (host->flags & SDHCI_DEVICE_DEAD) {
> -		if (!IS_ERR(mmc->supply.vmmc) &&
> -		    ios->power_mode == MMC_POWER_OFF)
> -			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
> -		return;
> -	}
>  
>  	/*
>  	 * Reset the chip on each power off.
> @@ -2359,8 +2345,6 @@ void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  		sdhci_enable_preset_value(host, false);
>  
>  	if (!ios->clock || ios->clock != host->clock) {
> -		turning_on_clk = ios->clock && !host->clock;
> -
>  		host->ops->set_clock(host, ios->clock);
>  		host->clock = ios->clock;
>  
> @@ -2381,6 +2365,32 @@ void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  		host->ops->set_power(host, ios->power_mode, ios->vdd);
>  	else
>  		sdhci_set_power(host, ios->power_mode, ios->vdd);
> +}
> +EXPORT_SYMBOL_GPL(sdhci_set_ios_common);
> +
> +void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> +{
> +	struct sdhci_host *host = mmc_priv(mmc);
> +	bool reinit_uhs = host->reinit_uhs;
> +	bool turning_on_clk = false;
> +	u8 ctrl;
> +
> +	host->reinit_uhs = false;
> +
> +	if (ios->power_mode == MMC_POWER_UNDEFINED)
> +		return;
> +
> +	if (host->flags & SDHCI_DEVICE_DEAD) {
> +		if (!IS_ERR(mmc->supply.vmmc) &&
> +		    ios->power_mode == MMC_POWER_OFF)
> +			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
> +		return;
> +	}
> +
> +	sdhci_set_ios_common(mmc, ios);
> +
> +	if (!ios->clock || ios->clock != host->clock)
> +		turning_on_clk = ios->clock && !host->clock;
>  
>  	if (host->ops->platform_send_init_74_clocks)
>  		host->ops->platform_send_init_74_clocks(host, ios->power_mode);
> @@ -2959,7 +2969,7 @@ int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>  }
>  EXPORT_SYMBOL_GPL(sdhci_execute_tuning);
>  
> -static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable)
> +void sdhci_enable_preset_value(struct sdhci_host *host, bool enable)
>  {
>  	/* Host Controller v3.00 defines preset value registers */
>  	if (host->version < SDHCI_SPEC_300)
> @@ -2987,6 +2997,7 @@ static void sdhci_enable_preset_value(struct sdhci_host *host, bool enable)
>  		host->preset_enabled = enable;
>  	}
>  }
> +EXPORT_SYMBOL_GPL(sdhci_enable_preset_value);
>  
>  static void sdhci_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
>  				int err)
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index df7fa0c0ebf8..c2f989dc2361 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -850,6 +850,8 @@ void sdhci_set_bus_width(struct sdhci_host *host, int width);
>  void sdhci_reset(struct sdhci_host *host, u8 mask);
>  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);
> +void sdhci_set_ios_common(struct mmc_host *mmc, struct mmc_ios *ios);
>  void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios);
>  int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
>  				      struct mmc_ios *ios);