Re: [PATCH V5 21/26] mmc: sdhci-uhs2: add add_host() and others to set up the driver

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

On 19/10/22 14:06, Victor Shih wrote:
> This is a UHS-II version of sdhci's add_host/remove_host operation.
> Any sdhci drivers which are capable of handling UHS-II cards must
> call those functions instead of the corresponding sdhci's.
> 
> 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 | 172 ++++++++++++++++++++++++++++++++++
>  drivers/mmc/host/sdhci-uhs2.h |   2 +
>  drivers/mmc/host/sdhci.c      |  21 +++--
>  drivers/mmc/host/sdhci.h      |   9 ++
>  4 files changed, 197 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index 883e18d849ad..eb3241bf95a2 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -15,6 +15,7 @@
>  #include <linux/ktime.h>
>  #include <linux/module.h>
>  #include <linux/mmc/mmc.h>
> +#include <linux/regulator/consumer.h>
>  
>  #include "sdhci.h"
>  #include "sdhci-uhs2.h"
> @@ -1177,6 +1178,177 @@ static irqreturn_t sdhci_uhs2_thread_irq(int irq, void *dev_id)
>  	return IRQ_HANDLED;
>  }
>  
> +/*****************************************************************************\
> + *
> + * Device allocation/registration                                            *
> + *                                                                           *
> +\*****************************************************************************/
> +
> +static int __sdhci_uhs2_add_host_v4(struct sdhci_host *host, u32 caps1)
> +{
> +	struct mmc_host *mmc;
> +	u32 max_current_caps2;
> +
> +	if (host->version < SDHCI_SPEC_400)
> +		return 0;
> +
> +	mmc = host->mmc;
> +
> +	/* Support UHS2 */
> +	if (caps1 & SDHCI_SUPPORT_UHS2)
> +		mmc->caps2 |= MMC_CAP2_SD_UHS2;
> +
> +	max_current_caps2 = sdhci_readl(host, SDHCI_MAX_CURRENT_1);
> +
> +	if ((caps1 & SDHCI_SUPPORT_VDD2_180) &&
> +	    !max_current_caps2 &&
> +	    !IS_ERR(mmc->supply.vmmc2)) {
> +		/* UHS2 - VDD2 */
> +		int curr = regulator_get_current_limit(mmc->supply.vmmc2);
> +
> +		if (curr > 0) {
> +			/* convert to SDHCI_MAX_CURRENT format */
> +			curr = curr / 1000;  /* convert to mA */
> +			curr = curr / SDHCI_MAX_CURRENT_MULTIPLIER;
> +			curr = min_t(u32, curr, SDHCI_MAX_CURRENT_LIMIT);
> +			max_current_caps2 = curr;
> +		}
> +	}
> +
> +	if (caps1 & SDHCI_SUPPORT_VDD2_180) {
> +		mmc->ocr_avail_uhs2 |= MMC_VDD2_165_195;
> +		/*
> +		 * UHS2 doesn't require this. Only UHS-I bus needs to set
> +		 * max current.
> +		 */
> +		mmc->max_current_180_vdd2 = (max_current_caps2 &
> +					SDHCI_MAX_CURRENT_VDD2_180_MASK) *
> +					SDHCI_MAX_CURRENT_MULTIPLIER;
> +	} else {
> +		mmc->caps2 &= ~MMC_CAP2_SD_UHS2;
> +	}
> +
> +	return 0;
> +}
> +
> +static int sdhci_uhs2_host_ops_init(struct sdhci_host *host);
> +
> +static int __sdhci_uhs2_add_host(struct sdhci_host *host)

The only thing this does differently is to use
sdhci_uhs2_complete_work() and sdhci_uhs2_thread_irq().
Better to add variables in struct sdhci_host, set them in
sdhci_alloc_host:

	host->complete_work_fn = sdhci_complete_work;
	host->thread_irq_fn = sdhci_thread_irq;

override them in sdhci_uhs2_add_host():

	host->complete_work_fn = sdhci_uhs2_complete_work;
	host->thread_irq_fn = sdhci_uhs2_thread_irq;

and use them in __sdhci_add_host().

> +{
> +	unsigned int flags = WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_HIGHPRI;
> +	struct mmc_host *mmc = host->mmc;
> +	int ret;
> +
> +	if ((mmc->caps2 & MMC_CAP2_CQE) &&
> +	    (host->quirks & SDHCI_QUIRK_BROKEN_CQE)) {
> +		mmc->caps2 &= ~MMC_CAP2_CQE;
> +		mmc->cqe_ops = NULL;
> +	}
> +
> +	/* overwrite ops */
> +	if (mmc->caps2 & MMC_CAP2_SD_UHS2)
> +		sdhci_uhs2_host_ops_init(host);

Do in sdhci_uhs2_add_host() instead of here

> +
> +	host->complete_wq = alloc_workqueue("sdhci", flags, 0);
> +	if (!host->complete_wq)
> +		return -ENOMEM;
> +
> +	INIT_WORK(&host->complete_work, sdhci_uhs2_complete_work);
> +
> +	timer_setup(&host->timer, sdhci_timeout_timer, 0);
> +	timer_setup(&host->data_timer, sdhci_timeout_data_timer, 0);
> +
> +	init_waitqueue_head(&host->buf_ready_int);
> +
> +	sdhci_init(host, 0);
> +
> +	ret = request_threaded_irq(host->irq, sdhci_irq,
> +				   sdhci_uhs2_thread_irq,
> +				   IRQF_SHARED,	mmc_hostname(mmc), host);
> +	if (ret) {
> +		pr_err("%s: Failed to request IRQ %d: %d\n",
> +		       mmc_hostname(mmc), host->irq, ret);
> +		goto unwq;
> +	}
> +
> +	ret = mmc_add_host(mmc);
> +		if (ret)
> +			return 1;
> +
> +	pr_info("%s: SDHCI controller on %s [%s] using %s\n",
> +		mmc_hostname(mmc), host->hw_name, dev_name(mmc_dev(mmc)),
> +		host->use_external_dma ? "External DMA" :
> +		(host->flags & SDHCI_USE_ADMA) ?
> +		(host->flags & SDHCI_USE_64_BIT_DMA) ? "ADMA 64-bit" : "ADMA" :
> +		(host->flags & SDHCI_USE_SDMA) ? "DMA" : "PIO");
> +
> +	sdhci_enable_card_detection(host);
> +
> +	return 0;
> +
> +unwq:
> +	destroy_workqueue(host->complete_wq);
> +
> +	return ret;
> +}
> +
> +static void __sdhci_uhs2_remove_host(struct sdhci_host *host, int dead)
> +{
> +	if (!(host->mmc) || !(host->mmc->flags & MMC_UHS2_SUPPORT))
> +		return;

Just use sdhci_uhs2_mode() i.e

	if (!sdhci_uhs2_mode(host))
		return;

> +
> +	if (!dead)
> +		host->ops->uhs2_reset(host, SDHCI_UHS2_SW_RESET_FULL);
> +
> +	sdhci_writel(host, 0, SDHCI_UHS2_ERR_INT_STATUS_EN);
> +	sdhci_writel(host, 0, SDHCI_UHS2_ERR_INT_SIG_EN);

Do not write registers if it is dead.

> +	host->mmc->flags &= ~MMC_UHS2_INITIALIZED;

Not the drivers job to change host->mmc->flags

> +}
> +
> +int sdhci_uhs2_add_host(struct sdhci_host *host)
> +{
> +	struct mmc_host *mmc = host->mmc;
> +	int ret;
> +
> +	ret = sdhci_setup_host(host);
> +	if (ret)
> +		return ret;
> +
> +	if (host->version >= SDHCI_SPEC_400) {
> +		ret = __sdhci_uhs2_add_host_v4(host, host->caps1);
> +		if (ret)
> +			goto cleanup;
> +	}
> +
> +	if ((mmc->caps2 & MMC_CAP2_SD_UHS2) && !host->v4_mode)
> +		/* host doesn't want to enable UHS2 support */
> +		/* FIXME: Do we have to do some cleanup here? */
> +		mmc->caps2 &= ~MMC_CAP2_SD_UHS2;
> +
> +	ret = __sdhci_uhs2_add_host(host);
> +	if (ret)
> +		goto cleanup2;
> +
> +	return 0;
> +
> +cleanup2:
> +	if (host->version >= SDHCI_SPEC_400)
> +		__sdhci_uhs2_remove_host(host, 0);
> +cleanup:
> +	sdhci_cleanup_host(host);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(sdhci_uhs2_add_host);
> +
> +void sdhci_uhs2_remove_host(struct sdhci_host *host, int dead)
> +{
> +	__sdhci_uhs2_remove_host(host, dead);
> +
> +	sdhci_remove_host(host, dead);
> +}
> +EXPORT_SYMBOL_GPL(sdhci_uhs2_remove_host);
> +
>  void sdhci_uhs2_request(struct mmc_host *mmc, struct mmc_request *mrq)
>  {
>  	struct sdhci_host *host = mmc_priv(mmc);
> diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
> index d32a8602d045..54241a7adfca 100644
> --- a/drivers/mmc/host/sdhci-uhs2.h
> +++ b/drivers/mmc/host/sdhci-uhs2.h
> @@ -220,5 +220,7 @@ void sdhci_uhs2_clear_set_irqs(struct sdhci_host *host, u32 clear, u32 set);
>  void sdhci_uhs2_request(struct mmc_host *mmc, struct mmc_request *mrq);
>  int sdhci_uhs2_request_atomic(struct mmc_host *mmc, struct mmc_request *mrq);
>  u32 sdhci_uhs2_irq(struct sdhci_host *host, u32 intmask);
> +int sdhci_uhs2_add_host(struct sdhci_host *host);
> +void sdhci_uhs2_remove_host(struct sdhci_host *host, int dead);
>  
>  #endif /* __SDHCI_UHS2_H */
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index e44ede049559..df433ad0ba66 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -173,10 +173,11 @@ static void sdhci_set_card_detection(struct sdhci_host *host, bool enable)
>  	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
>  }
>  
> -static void sdhci_enable_card_detection(struct sdhci_host *host)
> +void sdhci_enable_card_detection(struct sdhci_host *host)
>  {
>  	sdhci_set_card_detection(host, true);
>  }
> +EXPORT_SYMBOL_GPL(sdhci_enable_card_detection);
>  
>  static void sdhci_disable_card_detection(struct sdhci_host *host)
>  {
> @@ -365,7 +366,7 @@ static void sdhci_config_dma(struct sdhci_host *host)
>  	sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
>  }
>  
> -static void sdhci_init(struct sdhci_host *host, int soft)
> +void sdhci_init(struct sdhci_host *host, int soft)
>  {
>  	struct mmc_host *mmc = host->mmc;
>  	unsigned long flags;
> @@ -390,6 +391,7 @@ static void sdhci_init(struct sdhci_host *host, int soft)
>  		mmc->ops->set_ios(mmc, &mmc->ios);
>  	}
>  }
> +EXPORT_SYMBOL_GPL(sdhci_init);
>  
>  static void sdhci_reinit(struct sdhci_host *host)
>  {
> @@ -454,7 +456,7 @@ static void sdhci_led_control(struct led_classdev *led,
>  	spin_unlock_irqrestore(&host->lock, flags);
>  }
>  
> -static int sdhci_led_register(struct sdhci_host *host)
> +int sdhci_led_register(struct sdhci_host *host)
>  {
>  	struct mmc_host *mmc = host->mmc;
>  
> @@ -471,14 +473,16 @@ static int sdhci_led_register(struct sdhci_host *host)
>  
>  	return led_classdev_register(mmc_dev(mmc), &host->led);
>  }
> +EXPORT_SYMBOL_GPL(sdhci_led_register);
>  
> -static void sdhci_led_unregister(struct sdhci_host *host)
> +void sdhci_led_unregister(struct sdhci_host *host)
>  {
>  	if (host->quirks & SDHCI_QUIRK_NO_LED)
>  		return;
>  
>  	led_classdev_unregister(&host->led);
>  }
> +EXPORT_SYMBOL_GPL(sdhci_led_unregister);
>  
>  static inline void sdhci_led_activate(struct sdhci_host *host)
>  {
> @@ -3244,7 +3248,7 @@ static void sdhci_complete_work(struct work_struct *work)
>  		;
>  }
>  
> -static void sdhci_timeout_timer(struct timer_list *t)
> +void sdhci_timeout_timer(struct timer_list *t)
>  {
>  	struct sdhci_host *host;
>  	unsigned long flags;
> @@ -3265,8 +3269,9 @@ static void sdhci_timeout_timer(struct timer_list *t)
>  
>  	spin_unlock_irqrestore(&host->lock, flags);
>  }
> +EXPORT_SYMBOL_GPL(sdhci_timeout_timer);
>  
> -static void sdhci_timeout_data_timer(struct timer_list *t)
> +void sdhci_timeout_data_timer(struct timer_list *t)
>  {
>  	struct sdhci_host *host;
>  	unsigned long flags;
> @@ -3297,6 +3302,7 @@ static void sdhci_timeout_data_timer(struct timer_list *t)
>  
>  	spin_unlock_irqrestore(&host->lock, flags);
>  }
> +EXPORT_SYMBOL_GPL(sdhci_timeout_data_timer);
>  
>  /*****************************************************************************\
>   *                                                                           *
> @@ -3560,7 +3566,7 @@ static inline bool sdhci_defer_done(struct sdhci_host *host,
>  		data->host_cookie == COOKIE_MAPPED);
>  }
>  
> -static irqreturn_t sdhci_irq(int irq, void *dev_id)
> +irqreturn_t sdhci_irq(int irq, void *dev_id)
>  {
>  	struct mmc_request *mrqs_done[SDHCI_MAX_MRQS] = {0};
>  	irqreturn_t result = IRQ_NONE;
> @@ -3701,6 +3707,7 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
>  
>  	return result;
>  }
> +EXPORT_SYMBOL_GPL(sdhci_irq);

This doesn't need to be exported when __sdhci_uhs2_add_host()
isn't needed.

>  
>  static irqreturn_t sdhci_thread_irq(int irq, void *dev_id)
>  {
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 49de8fdbd7a3..0970fe392d49 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -851,8 +851,14 @@ static inline void sdhci_read_caps(struct sdhci_host *host)
>  }
>  
>  bool sdhci_data_line_cmd(struct mmc_command *cmd);
> +void sdhci_enable_card_detection(struct sdhci_host *host);
>  void sdhci_runtime_pm_bus_on(struct sdhci_host *host);
>  void sdhci_runtime_pm_bus_off(struct sdhci_host *host);
> +void sdhci_init(struct sdhci_host *host, int soft);
> +#if IS_REACHABLE(CONFIG_LEDS_CLASS)
> +int sdhci_led_register(struct sdhci_host *host);
> +void sdhci_led_unregister(struct sdhci_host *host);
> +#endif

Don't support LEDs.  Just set:

	/* LED support not implemented for UHS2 */
	host->quirks |= SDHCI_QUIRK_NO_LED;

>  void sdhci_mod_timer(struct sdhci_host *host, struct mmc_request *mrq, unsigned long timeout);
>  void sdhci_initialize_data(struct sdhci_host *host, struct mmc_data *data);
>  void sdhci_prepare_dma(struct sdhci_host *host, struct mmc_data *data);
> @@ -900,6 +906,9 @@ int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
>  void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable);
>  void sdhci_request_done_dma(struct sdhci_host *host, struct mmc_request *mrq);
>  bool sdhci_request_done(struct sdhci_host *host);
> +void sdhci_timeout_timer(struct timer_list *t);
> +void sdhci_timeout_data_timer(struct timer_list *t);
> +irqreturn_t sdhci_irq(int irq, void *dev_id);
>  void sdhci_adma_write_desc(struct sdhci_host *host, void **desc,
>  			   dma_addr_t addr, int len, unsigned int cmd);
>