[PATCH v3 0/1] mmc: dw_mmc: Add runtime pm to dw_mmc

[PATCH v3 0/1] mmc: dw_mmc: Add runtime pm to dw_mmc

[Karol Wrona]

Hello,

This patch adds runtime pm for dw_mmc.  There is no runtime pm callbacks for
exynos dw_mmc because the host hardware gates interface clock itself and it is
done separately.  The reason for runtime is mainly get an info about host state
for now.

>From v1:
	- move all pm_runtime functions to dw_mmc.c
	- change runtime autosuspend timeout

>From v2:
	- rebase on next-20150306


Thanks,
Karol

Karol Wrona (1):
  mmc: dw_mmc: Add runtime pm to dw_mmc

 drivers/mmc/host/dw_mmc.c |  103 ++++++++++++++++++++++++++++++++++++++++++---
 drivers/mmc/host/dw_mmc.h |    2 +
 2 files changed, 99 insertions(+), 6 deletions(-)

-- 
1.7.9.5

[PATCH v3 1/1] mmc: dw_mmc: Add runtime pm to dw_mmc

[Karol Wrona]

This patch adds runtime pm handling to dw_mmc.
It mainly uses mci_request/mci_request_end for mmc host state information.
The goal of the runtime pm in dw_mmc host is mainly for giving an information
for containing it power domain about its activity.

Signed-off-by: Karol Wrona <k.wrona@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/mmc/host/dw_mmc.c |  103 ++++++++++++++++++++++++++++++++++++++++++---
 drivers/mmc/host/dw_mmc.h |    2 +
 2 files changed, 99 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 47dfd0e..4f45932 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -38,6 +38,7 @@
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/mmc/slot-gpio.h>
+#include <linux/pm_runtime.h>
 
 #include "dw_mmc.h"
 
@@ -113,6 +114,8 @@ static int dw_mci_req_show(struct seq_file *s, void *v)
 	struct mmc_command *stop;
 	struct mmc_data	*data;
 
+	pm_runtime_get_sync(slot->host->dev);
+
 	/* Make sure we get a consistent snapshot */
 	spin_lock_bh(&slot->host->lock);
 	mrq = slot->mrq;
@@ -142,6 +145,9 @@ static int dw_mci_req_show(struct seq_file *s, void *v)
 
 	spin_unlock_bh(&slot->host->lock);
 
+	pm_runtime_mark_last_busy(slot->host->dev);
+	pm_runtime_put_autosuspend(slot->host->dev);
+
 	return 0;
 }
 
@@ -1071,6 +1077,8 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 
 	WARN_ON(slot->mrq);
 
+	pm_runtime_get_sync(host->dev);
+
 	/*
 	 * The check for card presence and queueing of the request must be
 	 * atomic, otherwise the card could be removed in between and the
@@ -1082,6 +1090,9 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 		spin_unlock_bh(&host->lock);
 		mrq->cmd->error = -ENOMEDIUM;
 		mmc_request_done(mmc, mrq);
+
+		pm_runtime_mark_last_busy(host->dev);
+		pm_runtime_put_autosuspend(host->dev);
 		return;
 	}
 
@@ -1109,6 +1120,8 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 		slot->ctype = SDMMC_CTYPE_1BIT;
 	}
 
+	pm_runtime_get_sync(slot->host->dev);
+
 	regs = mci_readl(slot->host, UHS_REG);
 
 	/* DDR mode set */
@@ -1139,7 +1152,7 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 				dev_err(slot->host->dev,
 					"failed to enable vmmc regulator\n");
 				/*return, if failed turn on vmmc*/
-				return;
+				goto _end;
 			}
 		}
 		set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
@@ -1192,6 +1205,10 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
 	if (slot->host->state == STATE_WAITING_CMD11_DONE && ios->clock != 0)
 		slot->host->state = STATE_IDLE;
+
+_end:
+	pm_runtime_mark_last_busy(slot->host->dev);
+	pm_runtime_put_autosuspend(slot->host->dev);
 }
 
 static int dw_mci_card_busy(struct mmc_host *mmc)
@@ -1199,12 +1216,17 @@ static int dw_mci_card_busy(struct mmc_host *mmc)
 	struct dw_mci_slot *slot = mmc_priv(mmc);
 	u32 status;
 
+	pm_runtime_get_sync(slot->host->dev);
+
 	/*
 	 * Check the busy bit which is low when DAT[3:0]
 	 * (the data lines) are 0000
 	 */
 	status = mci_readl(slot->host, STATUS);
 
+	pm_runtime_mark_last_busy(slot->host->dev);
+	pm_runtime_put_autosuspend(slot->host->dev);
+
 	return !!(status & SDMMC_STATUS_BUSY);
 }
 
@@ -1217,6 +1239,8 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
 	int min_uv, max_uv;
 	int ret;
 
+	pm_runtime_get_sync(host->dev);
+
 	/*
 	 * Program the voltage.  Note that some instances of dw_mmc may use
 	 * the UHS_REG for this.  For other instances (like exynos) the UHS_REG
@@ -1239,11 +1263,17 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
 			dev_dbg(&mmc->class_dev,
 					 "Regulator set error %d: %d - %d\n",
 					 ret, min_uv, max_uv);
+
+			pm_runtime_mark_last_busy(host->dev);
+			pm_runtime_put_autosuspend(host->dev);
 			return ret;
 		}
 	}
 	mci_writel(host, UHS_REG, uhs);
 
+	pm_runtime_mark_last_busy(host->dev);
+	pm_runtime_put_autosuspend(host->dev);
+
 	return 0;
 }
 
@@ -1253,6 +1283,8 @@ static int dw_mci_get_ro(struct mmc_host *mmc)
 	struct dw_mci_slot *slot = mmc_priv(mmc);
 	int gpio_ro = mmc_gpio_get_ro(mmc);
 
+	pm_runtime_get_sync(slot->host->dev);
+
 	/* Use platform get_ro function, else try on board write protect */
 	if ((slot->quirks & DW_MCI_SLOT_QUIRK_NO_WRITE_PROTECT) ||
 			(slot->host->quirks & DW_MCI_QUIRK_NO_WRITE_PROTECT))
@@ -1263,6 +1295,9 @@ static int dw_mci_get_ro(struct mmc_host *mmc)
 		read_only =
 			mci_readl(slot->host, WRTPRT) & (1 << slot->id) ? 1 : 0;
 
+	pm_runtime_mark_last_busy(slot->host->dev);
+	pm_runtime_put_autosuspend(slot->host->dev);
+
 	dev_dbg(&mmc->class_dev, "card is %s\n",
 		read_only ? "read-only" : "read-write");
 
@@ -1277,6 +1312,8 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
 	struct dw_mci *host = slot->host;
 	int gpio_cd = mmc_gpio_get_cd(mmc);
 
+	pm_runtime_get_sync(host->dev);
+
 	/* Use platform get_cd function, else try onboard card detect */
 	if (brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
 		present = 1;
@@ -1296,6 +1333,9 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
 	}
 	spin_unlock_bh(&host->lock);
 
+	pm_runtime_mark_last_busy(host->dev);
+	pm_runtime_put_autosuspend(host->dev);
+
 	return present;
 }
 
@@ -1304,6 +1344,8 @@ static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
 	struct dw_mci_slot *slot = mmc_priv(mmc);
 	struct dw_mci *host = slot->host;
 
+	pm_runtime_get_sync(host->dev);
+
 	/*
 	 * Low power mode will stop the card clock when idle.  According to the
 	 * description of the CLKENA register we should disable low power mode
@@ -1331,6 +1373,9 @@ static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
 				     SDMMC_CMD_PRV_DAT_WAIT, 0);
 		}
 	}
+
+	pm_runtime_mark_last_busy(host->dev);
+	pm_runtime_put_autosuspend(host->dev);
 }
 
 static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
@@ -1340,6 +1385,9 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
 	unsigned long irqflags;
 	u32 int_mask;
 
+	if (enb)
+		pm_runtime_get_sync(slot->host->dev);
+
 	spin_lock_irqsave(&host->irq_lock, irqflags);
 
 	/* Enable/disable Slot Specific SDIO interrupt */
@@ -1351,6 +1399,12 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
 	mci_writel(host, INTMASK, int_mask);
 
 	spin_unlock_irqrestore(&host->irq_lock, irqflags);
+
+	/* If interrupt is enabled leave device active. */
+	if (!enb) {
+		pm_runtime_mark_last_busy(slot->host->dev);
+		pm_runtime_put_autosuspend(slot->host->dev);
+	}
 }
 
 static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
@@ -1360,8 +1414,14 @@ static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	const struct dw_mci_drv_data *drv_data = host->drv_data;
 	int err = -ENOSYS;
 
+	pm_runtime_get_sync(host->dev);
+
 	if (drv_data && drv_data->execute_tuning)
 		err = drv_data->execute_tuning(slot);
+
+	pm_runtime_mark_last_busy(host->dev);
+	pm_runtime_put_autosuspend(host->dev);
+
 	return err;
 }
 
@@ -1371,9 +1431,14 @@ static int dw_mci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios
 	struct dw_mci *host = slot->host;
 	const struct dw_mci_drv_data *drv_data = host->drv_data;
 
+	pm_runtime_get_sync(host->dev);
+
 	if (drv_data && drv_data->prepare_hs400_tuning)
 		return drv_data->prepare_hs400_tuning(host, ios);
 
+	pm_runtime_mark_last_busy(host->dev);
+	pm_runtime_put_autosuspend(host->dev);
+
 	return 0;
 }
 
@@ -1414,10 +1479,14 @@ static void dw_mci_request_end(struct dw_mci *host, struct mmc_request *mrq)
 	} else {
 		dev_vdbg(host->dev, "list empty\n");
 
-		if (host->state == STATE_SENDING_CMD11)
+		if (host->state == STATE_SENDING_CMD11) {
 			host->state = STATE_WAITING_CMD11_DONE;
-		else
+		} else {
+			pm_runtime_mark_last_busy(host->dev);
+			pm_runtime_put_autosuspend(host->dev);
+
 			host->state = STATE_IDLE;
+		}
 	}
 
 	spin_unlock(&host->lock);
@@ -2688,6 +2757,11 @@ int dw_mci_probe(struct dw_mci *host)
 		return -ENODEV;
 	}
 
+	pm_runtime_enable(host->dev);
+	pm_runtime_get_sync(host->dev);
+	pm_runtime_set_autosuspend_delay(host->dev, DWMMC_AUTOSUSPEND_DELAY);
+	pm_runtime_use_autosuspend(host->dev);
+
 	host->biu_clk = devm_clk_get(host->dev, "biu");
 	if (IS_ERR(host->biu_clk)) {
 		dev_dbg(host->dev, "biu clock not available\n");
@@ -2877,6 +2951,9 @@ int dw_mci_probe(struct dw_mci *host)
 	if (host->quirks & DW_MCI_QUIRK_IDMAC_DTO)
 		dev_info(host->dev, "Internal DMAC interrupt fix enabled.\n");
 
+	pm_runtime_mark_last_busy(host->dev);
+	pm_runtime_put_autosuspend(host->dev);
+
 	return 0;
 
 err_dmaunmap:
@@ -2891,6 +2968,9 @@ err_clk_biu:
 	if (!IS_ERR(host->biu_clk))
 		clk_disable_unprepare(host->biu_clk);
 
+	pm_runtime_put_sync(host->dev);
+	pm_runtime_disable(host->dev);
+
 	return ret;
 }
 EXPORT_SYMBOL(dw_mci_probe);
@@ -2899,6 +2979,8 @@ void dw_mci_remove(struct dw_mci *host)
 {
 	int i;
 
+	pm_runtime_get_sync(host->dev);
+
 	mci_writel(host, RINTSTS, 0xFFFFFFFF);
 	mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */
 
@@ -2915,6 +2997,9 @@ void dw_mci_remove(struct dw_mci *host)
 	if (host->use_dma && host->dma_ops->exit)
 		host->dma_ops->exit(host);
 
+	pm_runtime_put_sync(host->dev);
+	pm_runtime_disable(host->dev);
+
 	if (!IS_ERR(host->ciu_clk))
 		clk_disable_unprepare(host->ciu_clk);
 
@@ -2937,11 +3022,14 @@ EXPORT_SYMBOL(dw_mci_suspend);
 
 int dw_mci_resume(struct dw_mci *host)
 {
-	int i, ret;
+	int i;
+
+	pm_runtime_get_sync(host->dev);
 
 	if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
-		ret = -ENODEV;
-		return ret;
+		pm_runtime_mark_last_busy(host->dev);
+		pm_runtime_put_autosuspend(host->dev);
+		return -ENODEV;
 	}
 
 	if (host->use_dma && host->dma_ops->init)
@@ -2976,6 +3064,9 @@ int dw_mci_resume(struct dw_mci *host)
 	/* Now that slots are all setup, we can enable card detect */
 	dw_mci_enable_cd(host);
 
+	pm_runtime_mark_last_busy(host->dev);
+	pm_runtime_put_autosuspend(host->dev);
+
 	return 0;
 }
 EXPORT_SYMBOL(dw_mci_resume);
diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
index d239867..2317f4b7 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h
@@ -209,6 +209,8 @@ extern int dw_mci_suspend(struct dw_mci *host);
 extern int dw_mci_resume(struct dw_mci *host);
 #endif
 
+#define DWMMC_AUTOSUSPEND_DELAY 50
+
 /**
  * struct dw_mci_slot - MMC slot state
  * @mmc: The mmc_host representing this slot.
-- 
1.7.9.5

Re: [PATCH v3 1/1] mmc: dw_mmc: Add runtime pm to dw_mmc

[Jaehoon Chung]

Hi, Karol.

Is there the benefit of power consumption? If there is, could you share the result?

On 03/09/2015 10:46 PM, Karol Wrona wrote:
> This patch adds runtime pm handling to dw_mmc.
> It mainly uses mci_request/mci_request_end for mmc host state information.
> The goal of the runtime pm in dw_mmc host is mainly for giving an information
> for containing it power domain about its activity.
> 
> Signed-off-by: Karol Wrona <k.wrona@samsung.com>
> Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
>  drivers/mmc/host/dw_mmc.c |  103 ++++++++++++++++++++++++++++++++++++++++++---
>  drivers/mmc/host/dw_mmc.h |    2 +
>  2 files changed, 99 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 47dfd0e..4f45932 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -38,6 +38,7 @@
>  #include <linux/of.h>
>  #include <linux/of_gpio.h>
>  #include <linux/mmc/slot-gpio.h>
> +#include <linux/pm_runtime.h>
>  
>  #include "dw_mmc.h"
>  
> @@ -113,6 +114,8 @@ static int dw_mci_req_show(struct seq_file *s, void *v)
>  	struct mmc_command *stop;
>  	struct mmc_data	*data;
>  
> +	pm_runtime_get_sync(slot->host->dev);
> +
>  	/* Make sure we get a consistent snapshot */
>  	spin_lock_bh(&slot->host->lock);
>  	mrq = slot->mrq;
> @@ -142,6 +145,9 @@ static int dw_mci_req_show(struct seq_file *s, void *v)
>  
>  	spin_unlock_bh(&slot->host->lock);
>  
> +	pm_runtime_mark_last_busy(slot->host->dev);
> +	pm_runtime_put_autosuspend(slot->host->dev);
> +

I suggest to use dw_mci_pm_runtime_get/put(). (refer to sdhci.c)

static int dw_mci_pm_rumtime_get(struct dw_mci *host)
{
	....
}

static int dw_mci_runtime_put(struct dw_mci *host)
{
	....
}


>  	return 0;
>  }
>  
> @@ -1071,6 +1077,8 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
>  
>  	WARN_ON(slot->mrq);
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	/*
>  	 * The check for card presence and queueing of the request must be
>  	 * atomic, otherwise the card could be removed in between and the
> @@ -1082,6 +1090,9 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
>  		spin_unlock_bh(&host->lock);
>  		mrq->cmd->error = -ENOMEDIUM;
>  		mmc_request_done(mmc, mrq);
> +
> +		pm_runtime_mark_last_busy(host->dev);
> +		pm_runtime_put_autosuspend(host->dev);
>  		return;
>  	}
>  
> @@ -1109,6 +1120,8 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  		slot->ctype = SDMMC_CTYPE_1BIT;
>  	}
>  
> +	pm_runtime_get_sync(slot->host->dev);
> +
>  	regs = mci_readl(slot->host, UHS_REG);
>  
>  	/* DDR mode set */
> @@ -1139,7 +1152,7 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  				dev_err(slot->host->dev,
>  					"failed to enable vmmc regulator\n");
>  				/*return, if failed turn on vmmc*/
> -				return;
> +				goto _end;

why do you use underline? (goto _end -> goto out)

>  			}
>  		}
>  		set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
> @@ -1192,6 +1205,10 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  
>  	if (slot->host->state == STATE_WAITING_CMD11_DONE && ios->clock != 0)
>  		slot->host->state = STATE_IDLE;
> +
> +_end:
> +	pm_runtime_mark_last_busy(slot->host->dev);
> +	pm_runtime_put_autosuspend(slot->host->dev);
>  }
>  
>  static int dw_mci_card_busy(struct mmc_host *mmc)
> @@ -1199,12 +1216,17 @@ static int dw_mci_card_busy(struct mmc_host *mmc)
>  	struct dw_mci_slot *slot = mmc_priv(mmc);
>  	u32 status;
>  
> +	pm_runtime_get_sync(slot->host->dev);
> +
>  	/*
>  	 * Check the busy bit which is low when DAT[3:0]
>  	 * (the data lines) are 0000
>  	 */
>  	status = mci_readl(slot->host, STATUS);
>  
> +	pm_runtime_mark_last_busy(slot->host->dev);
> +	pm_runtime_put_autosuspend(slot->host->dev);
> +
>  	return !!(status & SDMMC_STATUS_BUSY);
>  }
>  
> @@ -1217,6 +1239,8 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
>  	int min_uv, max_uv;
>  	int ret;
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	/*
>  	 * Program the voltage.  Note that some instances of dw_mmc may use
>  	 * the UHS_REG for this.  For other instances (like exynos) the UHS_REG
> @@ -1239,11 +1263,17 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
>  			dev_dbg(&mmc->class_dev,
>  					 "Regulator set error %d: %d - %d\n",
>  					 ret, min_uv, max_uv);
> +
> +			pm_runtime_mark_last_busy(host->dev);
> +			pm_runtime_put_autosuspend(host->dev);
>  			return ret;

use the "goto statement"? (goto out;)

Best Regards,
Jaehoon Chung

>  		}
>  	}
>  	mci_writel(host, UHS_REG, uhs);
>  
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	return 0;
>  }
>  
> @@ -1253,6 +1283,8 @@ static int dw_mci_get_ro(struct mmc_host *mmc)
>  	struct dw_mci_slot *slot = mmc_priv(mmc);
>  	int gpio_ro = mmc_gpio_get_ro(mmc);
>  
> +	pm_runtime_get_sync(slot->host->dev);
> +
>  	/* Use platform get_ro function, else try on board write protect */
>  	if ((slot->quirks & DW_MCI_SLOT_QUIRK_NO_WRITE_PROTECT) ||
>  			(slot->host->quirks & DW_MCI_QUIRK_NO_WRITE_PROTECT))
> @@ -1263,6 +1295,9 @@ static int dw_mci_get_ro(struct mmc_host *mmc)
>  		read_only =
>  			mci_readl(slot->host, WRTPRT) & (1 << slot->id) ? 1 : 0;
>  
> +	pm_runtime_mark_last_busy(slot->host->dev);
> +	pm_runtime_put_autosuspend(slot->host->dev);
> +
>  	dev_dbg(&mmc->class_dev, "card is %s\n",
>  		read_only ? "read-only" : "read-write");
>  
> @@ -1277,6 +1312,8 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
>  	struct dw_mci *host = slot->host;
>  	int gpio_cd = mmc_gpio_get_cd(mmc);
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	/* Use platform get_cd function, else try onboard card detect */
>  	if (brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
>  		present = 1;
> @@ -1296,6 +1333,9 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
>  	}
>  	spin_unlock_bh(&host->lock);
>  
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	return present;
>  }
>  
> @@ -1304,6 +1344,8 @@ static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
>  	struct dw_mci_slot *slot = mmc_priv(mmc);
>  	struct dw_mci *host = slot->host;
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	/*
>  	 * Low power mode will stop the card clock when idle.  According to the
>  	 * description of the CLKENA register we should disable low power mode
> @@ -1331,6 +1373,9 @@ static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
>  				     SDMMC_CMD_PRV_DAT_WAIT, 0);
>  		}
>  	}
> +
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
>  }
>  
>  static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
> @@ -1340,6 +1385,9 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
>  	unsigned long irqflags;
>  	u32 int_mask;
>  
> +	if (enb)
> +		pm_runtime_get_sync(slot->host->dev);
> +
>  	spin_lock_irqsave(&host->irq_lock, irqflags);
>  
>  	/* Enable/disable Slot Specific SDIO interrupt */
> @@ -1351,6 +1399,12 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
>  	mci_writel(host, INTMASK, int_mask);
>  
>  	spin_unlock_irqrestore(&host->irq_lock, irqflags);
> +
> +	/* If interrupt is enabled leave device active. */
> +	if (!enb) {
> +		pm_runtime_mark_last_busy(slot->host->dev);
> +		pm_runtime_put_autosuspend(slot->host->dev);
> +	}
>  }
>  
>  static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> @@ -1360,8 +1414,14 @@ static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>  	const struct dw_mci_drv_data *drv_data = host->drv_data;
>  	int err = -ENOSYS;
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	if (drv_data && drv_data->execute_tuning)
>  		err = drv_data->execute_tuning(slot);
> +
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	return err;
>  }
>  
> @@ -1371,9 +1431,14 @@ static int dw_mci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios
>  	struct dw_mci *host = slot->host;
>  	const struct dw_mci_drv_data *drv_data = host->drv_data;
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	if (drv_data && drv_data->prepare_hs400_tuning)
>  		return drv_data->prepare_hs400_tuning(host, ios);
>  
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	return 0;
>  }
>  
> @@ -1414,10 +1479,14 @@ static void dw_mci_request_end(struct dw_mci *host, struct mmc_request *mrq)
>  	} else {
>  		dev_vdbg(host->dev, "list empty\n");
>  
> -		if (host->state == STATE_SENDING_CMD11)
> +		if (host->state == STATE_SENDING_CMD11) {
>  			host->state = STATE_WAITING_CMD11_DONE;
> -		else
> +		} else {
> +			pm_runtime_mark_last_busy(host->dev);
> +			pm_runtime_put_autosuspend(host->dev);
> +
>  			host->state = STATE_IDLE;
> +		}
>  	}
>  
>  	spin_unlock(&host->lock);
> @@ -2688,6 +2757,11 @@ int dw_mci_probe(struct dw_mci *host)
>  		return -ENODEV;
>  	}
>  
> +	pm_runtime_enable(host->dev);
> +	pm_runtime_get_sync(host->dev);
> +	pm_runtime_set_autosuspend_delay(host->dev, DWMMC_AUTOSUSPEND_DELAY);
> +	pm_runtime_use_autosuspend(host->dev);
> +
>  	host->biu_clk = devm_clk_get(host->dev, "biu");
>  	if (IS_ERR(host->biu_clk)) {
>  		dev_dbg(host->dev, "biu clock not available\n");
> @@ -2877,6 +2951,9 @@ int dw_mci_probe(struct dw_mci *host)
>  	if (host->quirks & DW_MCI_QUIRK_IDMAC_DTO)
>  		dev_info(host->dev, "Internal DMAC interrupt fix enabled.\n");
>  
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	return 0;
>  
>  err_dmaunmap:
> @@ -2891,6 +2968,9 @@ err_clk_biu:
>  	if (!IS_ERR(host->biu_clk))
>  		clk_disable_unprepare(host->biu_clk);
>  
> +	pm_runtime_put_sync(host->dev);
> +	pm_runtime_disable(host->dev);
> +
>  	return ret;
>  }
>  EXPORT_SYMBOL(dw_mci_probe);
> @@ -2899,6 +2979,8 @@ void dw_mci_remove(struct dw_mci *host)
>  {
>  	int i;
>  
> +	pm_runtime_get_sync(host->dev);
> +
>  	mci_writel(host, RINTSTS, 0xFFFFFFFF);
>  	mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */
>  
> @@ -2915,6 +2997,9 @@ void dw_mci_remove(struct dw_mci *host)
>  	if (host->use_dma && host->dma_ops->exit)
>  		host->dma_ops->exit(host);
>  
> +	pm_runtime_put_sync(host->dev);
> +	pm_runtime_disable(host->dev);
> +
>  	if (!IS_ERR(host->ciu_clk))
>  		clk_disable_unprepare(host->ciu_clk);
>  
> @@ -2937,11 +3022,14 @@ EXPORT_SYMBOL(dw_mci_suspend);
>  
>  int dw_mci_resume(struct dw_mci *host)
>  {
> -	int i, ret;
> +	int i;
> +
> +	pm_runtime_get_sync(host->dev);
>  
>  	if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
> -		ret = -ENODEV;
> -		return ret;
> +		pm_runtime_mark_last_busy(host->dev);
> +		pm_runtime_put_autosuspend(host->dev);
> +		return -ENODEV;
>  	}
>  
>  	if (host->use_dma && host->dma_ops->init)
> @@ -2976,6 +3064,9 @@ int dw_mci_resume(struct dw_mci *host)
>  	/* Now that slots are all setup, we can enable card detect */
>  	dw_mci_enable_cd(host);
>  
> +	pm_runtime_mark_last_busy(host->dev);
> +	pm_runtime_put_autosuspend(host->dev);
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL(dw_mci_resume);
> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
> index d239867..2317f4b7 100644
> --- a/drivers/mmc/host/dw_mmc.h
> +++ b/drivers/mmc/host/dw_mmc.h
> @@ -209,6 +209,8 @@ extern int dw_mci_suspend(struct dw_mci *host);
>  extern int dw_mci_resume(struct dw_mci *host);
>  #endif
>  
> +#define DWMMC_AUTOSUSPEND_DELAY 50
> +
>  /**
>   * struct dw_mci_slot - MMC slot state
>   * @mmc: The mmc_host representing this slot.
> 

Re: [PATCH v3 1/1] mmc: dw_mmc: Add runtime pm to dw_mmc

[Karol Wrona]

On 03/12/2015 03:08 AM, Jaehoon Chung wrote:
> Hi, Karol.
> 
> Is there the benefit of power consumption? If there is, could you share the result?

At this stage all I want to achieve is not directly mmc power
consumption drop but the ability to notify the pm about mmc host
activity.  The cpu should not enter LPA/LPD/WAFTR state when mmc host is
active.  I think we can do some experiments on the host later and do
something in runtime callbacks with clock gating but for now I do not
know how to do it.

Some ans. inline.

> 
> On 03/09/2015 10:46 PM, Karol Wrona wrote:
>> This patch adds runtime pm handling to dw_mmc.
>> It mainly uses mci_request/mci_request_end for mmc host state information.
>> The goal of the runtime pm in dw_mmc host is mainly for giving an information
>> for containing it power domain about its activity.
>>
>> Signed-off-by: Karol Wrona <k.wrona@samsung.com>
>> Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
>> ---
>>  drivers/mmc/host/dw_mmc.c |  103 ++++++++++++++++++++++++++++++++++++++++++---
>>  drivers/mmc/host/dw_mmc.h |    2 +
>>  2 files changed, 99 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 47dfd0e..4f45932 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -38,6 +38,7 @@
>>  #include <linux/of.h>
>>  #include <linux/of_gpio.h>
>>  #include <linux/mmc/slot-gpio.h>
>> +#include <linux/pm_runtime.h>
>>  
>>  #include "dw_mmc.h"
>>  
>> @@ -113,6 +114,8 @@ static int dw_mci_req_show(struct seq_file *s, void *v)
>>  	struct mmc_command *stop;
>>  	struct mmc_data	*data;
>>  
>> +	pm_runtime_get_sync(slot->host->dev);
>> +
>>  	/* Make sure we get a consistent snapshot */
>>  	spin_lock_bh(&slot->host->lock);
>>  	mrq = slot->mrq;
>> @@ -142,6 +145,9 @@ static int dw_mci_req_show(struct seq_file *s, void *v)
>>  
>>  	spin_unlock_bh(&slot->host->lock);
>>  
>> +	pm_runtime_mark_last_busy(slot->host->dev);
>> +	pm_runtime_put_autosuspend(slot->host->dev);
>> +
> 
> I suggest to use dw_mci_pm_runtime_get/put(). (refer to sdhci.c)
> 
> static int dw_mci_pm_rumtime_get(struct dw_mci *host)
> {
> 	....
> }
> 
> static int dw_mci_runtime_put(struct dw_mci *host)
> {
> 	....
> }
> 
> 
>>  	return 0;
>>  }

Frankly I would like to have such wrappers in pm than in every driver.
I will look through the lists if someone tried to add them.

>>  
>> @@ -1071,6 +1077,8 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
>>  
>>  	WARN_ON(slot->mrq);
>>  
>> +	pm_runtime_get_sync(host->dev);
>> +
>>  	/*
>>  	 * The check for card presence and queueing of the request must be
>>  	 * atomic, otherwise the card could be removed in between and the
>> @@ -1082,6 +1090,9 @@ static void dw_mci_request(struct mmc_host *mmc, struct mmc_request *mrq)
>>  		spin_unlock_bh(&host->lock);
>>  		mrq->cmd->error = -ENOMEDIUM;
>>  		mmc_request_done(mmc, mrq);
>> +
>> +		pm_runtime_mark_last_busy(host->dev);
>> +		pm_runtime_put_autosuspend(host->dev);
>>  		return;
>>  	}
>>  
>> @@ -1109,6 +1120,8 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>>  		slot->ctype = SDMMC_CTYPE_1BIT;
>>  	}
>>  
>> +	pm_runtime_get_sync(slot->host->dev);
>> +
>>  	regs = mci_readl(slot->host, UHS_REG);
>>  
>>  	/* DDR mode set */
>> @@ -1139,7 +1152,7 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>>  				dev_err(slot->host->dev,
>>  					"failed to enable vmmc regulator\n");
>>  				/*return, if failed turn on vmmc*/
>> -				return;
>> +				goto _end;
> 
> why do you use underline? (goto _end -> goto out)
Just as you wish.
> 
>>  			}
>>  		}
>>  		set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags);
>> @@ -1192,6 +1205,10 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>>  
>>  	if (slot->host->state == STATE_WAITING_CMD11_DONE && ios->clock != 0)
>>  		slot->host->state = STATE_IDLE;
>> +
>> +_end:
>> +	pm_runtime_mark_last_busy(slot->host->dev);
>> +	pm_runtime_put_autosuspend(slot->host->dev);
>>  }
>>  
>>  static int dw_mci_card_busy(struct mmc_host *mmc)
>> @@ -1199,12 +1216,17 @@ static int dw_mci_card_busy(struct mmc_host *mmc)
>>  	struct dw_mci_slot *slot = mmc_priv(mmc);
>>  	u32 status;
>>  
>> +	pm_runtime_get_sync(slot->host->dev);
>> +
>>  	/*
>>  	 * Check the busy bit which is low when DAT[3:0]
>>  	 * (the data lines) are 0000
>>  	 */
>>  	status = mci_readl(slot->host, STATUS);
>>  
>> +	pm_runtime_mark_last_busy(slot->host->dev);
>> +	pm_runtime_put_autosuspend(slot->host->dev);
>> +
>>  	return !!(status & SDMMC_STATUS_BUSY);
>>  }
>>  
>> @@ -1217,6 +1239,8 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
>>  	int min_uv, max_uv;
>>  	int ret;
>>  
>> +	pm_runtime_get_sync(host->dev);
>> +
>>  	/*
>>  	 * Program the voltage.  Note that some instances of dw_mmc may use
>>  	 * the UHS_REG for this.  For other instances (like exynos) the UHS_REG
>> @@ -1239,11 +1263,17 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
>>  			dev_dbg(&mmc->class_dev,
>>  					 "Regulator set error %d: %d - %d\n",
>>  					 ret, min_uv, max_uv);
>> +
>> +			pm_runtime_mark_last_busy(host->dev);
>> +			pm_runtime_put_autosuspend(host->dev);
>>  			return ret;
> 
> use the "goto statement"? (goto out;)
Just as you wish.

> 
> Best Regards,
> Jaehoon Chung
> 
>>  		}
>>  	}
>>  	mci_writel(host, UHS_REG, uhs);
>>  
>> +	pm_runtime_mark_last_busy(host->dev);
>> +	pm_runtime_put_autosuspend(host->dev);
>> +
>>  	return 0;
>>  }
>>  
>> @@ -1253,6 +1283,8 @@ static int dw_mci_get_ro(struct mmc_host *mmc)
>>  	struct dw_mci_slot *slot = mmc_priv(mmc);
>>  	int gpio_ro = mmc_gpio_get_ro(mmc);
>>  
>> +	pm_runtime_get_sync(slot->host->dev);
>> +
>>  	/* Use platform get_ro function, else try on board write protect */
>>  	if ((slot->quirks & DW_MCI_SLOT_QUIRK_NO_WRITE_PROTECT) ||
>>  			(slot->host->quirks & DW_MCI_QUIRK_NO_WRITE_PROTECT))
>> @@ -1263,6 +1295,9 @@ static int dw_mci_get_ro(struct mmc_host *mmc)
>>  		read_only =
>>  			mci_readl(slot->host, WRTPRT) & (1 << slot->id) ? 1 : 0;
>>  
>> +	pm_runtime_mark_last_busy(slot->host->dev);
>> +	pm_runtime_put_autosuspend(slot->host->dev);
>> +
>>  	dev_dbg(&mmc->class_dev, "card is %s\n",
>>  		read_only ? "read-only" : "read-write");
>>  
>> @@ -1277,6 +1312,8 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
>>  	struct dw_mci *host = slot->host;
>>  	int gpio_cd = mmc_gpio_get_cd(mmc);
>>  
>> +	pm_runtime_get_sync(host->dev);
>> +
>>  	/* Use platform get_cd function, else try onboard card detect */
>>  	if (brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
>>  		present = 1;
>> @@ -1296,6 +1333,9 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
>>  	}
>>  	spin_unlock_bh(&host->lock);
>>  
>> +	pm_runtime_mark_last_busy(host->dev);
>> +	pm_runtime_put_autosuspend(host->dev);
>> +
>>  	return present;
>>  }
>>  
>> @@ -1304,6 +1344,8 @@ static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
>>  	struct dw_mci_slot *slot = mmc_priv(mmc);
>>  	struct dw_mci *host = slot->host;
>>  
>> +	pm_runtime_get_sync(host->dev);
>> +
>>  	/*
>>  	 * Low power mode will stop the card clock when idle.  According to the
>>  	 * description of the CLKENA register we should disable low power mode
>> @@ -1331,6 +1373,9 @@ static void dw_mci_init_card(struct mmc_host *mmc, struct mmc_card *card)
>>  				     SDMMC_CMD_PRV_DAT_WAIT, 0);
>>  		}
>>  	}
>> +
>> +	pm_runtime_mark_last_busy(host->dev);
>> +	pm_runtime_put_autosuspend(host->dev);
>>  }
>>  
>>  static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
>> @@ -1340,6 +1385,9 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
>>  	unsigned long irqflags;
>>  	u32 int_mask;
>>  
>> +	if (enb)
>> +		pm_runtime_get_sync(slot->host->dev);
>> +
>>  	spin_lock_irqsave(&host->irq_lock, irqflags);
>>  
>>  	/* Enable/disable Slot Specific SDIO interrupt */
>> @@ -1351,6 +1399,12 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
>>  	mci_writel(host, INTMASK, int_mask);
>>  
>>  	spin_unlock_irqrestore(&host->irq_lock, irqflags);
>> +
>> +	/* If interrupt is enabled leave device active. */
>> +	if (!enb) {
>> +		pm_runtime_mark_last_busy(slot->host->dev);
>> +		pm_runtime_put_autosuspend(slot->host->dev);
>> +	}
>>  }
>>  
>>  static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> @@ -1360,8 +1414,14 @@ static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
>>  	const struct dw_mci_drv_data *drv_data = host->drv_data;
>>  	int err = -ENOSYS;
>>  
>> +	pm_runtime_get_sync(host->dev);
>> +
>>  	if (drv_data && drv_data->execute_tuning)
>>  		err = drv_data->execute_tuning(slot);
>> +
>> +	pm_runtime_mark_last_busy(host->dev);
>> +	pm_runtime_put_autosuspend(host->dev);
>> +
>>  	return err;
>>  }
>>  
>> @@ -1371,9 +1431,14 @@ static int dw_mci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios
>>  	struct dw_mci *host = slot->host;
>>  	const struct dw_mci_drv_data *drv_data = host->drv_data;
>>  
>> +	pm_runtime_get_sync(host->dev);
>> +
>>  	if (drv_data && drv_data->prepare_hs400_tuning)
>>  		return drv_data->prepare_hs400_tuning(host, ios);
>>  
>> +	pm_runtime_mark_last_busy(host->dev);
>> +	pm_runtime_put_autosuspend(host->dev);
>> +
>>  	return 0;
>>  }
>>  
>> @@ -1414,10 +1479,14 @@ static void dw_mci_request_end(struct dw_mci *host, struct mmc_request *mrq)
>>  	} else {
>>  		dev_vdbg(host->dev, "list empty\n");
>>  
>> -		if (host->state == STATE_SENDING_CMD11)
>> +		if (host->state == STATE_SENDING_CMD11) {
>>  			host->state = STATE_WAITING_CMD11_DONE;
>> -		else
>> +		} else {
>> +			pm_runtime_mark_last_busy(host->dev);
>> +			pm_runtime_put_autosuspend(host->dev);
>> +
>>  			host->state = STATE_IDLE;
>> +		}
>>  	}
>>  
>>  	spin_unlock(&host->lock);
>> @@ -2688,6 +2757,11 @@ int dw_mci_probe(struct dw_mci *host)
>>  		return -ENODEV;
>>  	}
>>  
>> +	pm_runtime_enable(host->dev);
>> +	pm_runtime_get_sync(host->dev);
>> +	pm_runtime_set_autosuspend_delay(host->dev, DWMMC_AUTOSUSPEND_DELAY);
>> +	pm_runtime_use_autosuspend(host->dev);
>> +
>>  	host->biu_clk = devm_clk_get(host->dev, "biu");
>>  	if (IS_ERR(host->biu_clk)) {
>>  		dev_dbg(host->dev, "biu clock not available\n");
>> @@ -2877,6 +2951,9 @@ int dw_mci_probe(struct dw_mci *host)
>>  	if (host->quirks & DW_MCI_QUIRK_IDMAC_DTO)
>>  		dev_info(host->dev, "Internal DMAC interrupt fix enabled.\n");
>>  
>> +	pm_runtime_mark_last_busy(host->dev);
>> +	pm_runtime_put_autosuspend(host->dev);
>> +
>>  	return 0;
>>  
>>  err_dmaunmap:
>> @@ -2891,6 +2968,9 @@ err_clk_biu:
>>  	if (!IS_ERR(host->biu_clk))
>>  		clk_disable_unprepare(host->biu_clk);
>>  
>> +	pm_runtime_put_sync(host->dev);
>> +	pm_runtime_disable(host->dev);
>> +
>>  	return ret;
>>  }
>>  EXPORT_SYMBOL(dw_mci_probe);
>> @@ -2899,6 +2979,8 @@ void dw_mci_remove(struct dw_mci *host)
>>  {
>>  	int i;
>>  
>> +	pm_runtime_get_sync(host->dev);
>> +
>>  	mci_writel(host, RINTSTS, 0xFFFFFFFF);
>>  	mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */
>>  
>> @@ -2915,6 +2997,9 @@ void dw_mci_remove(struct dw_mci *host)
>>  	if (host->use_dma && host->dma_ops->exit)
>>  		host->dma_ops->exit(host);
>>  
>> +	pm_runtime_put_sync(host->dev);
>> +	pm_runtime_disable(host->dev);
>> +
>>  	if (!IS_ERR(host->ciu_clk))
>>  		clk_disable_unprepare(host->ciu_clk);
>>  
>> @@ -2937,11 +3022,14 @@ EXPORT_SYMBOL(dw_mci_suspend);
>>  
>>  int dw_mci_resume(struct dw_mci *host)
>>  {
>> -	int i, ret;
>> +	int i;
>> +
>> +	pm_runtime_get_sync(host->dev);
>>  
>>  	if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
>> -		ret = -ENODEV;
>> -		return ret;
>> +		pm_runtime_mark_last_busy(host->dev);
>> +		pm_runtime_put_autosuspend(host->dev);
>> +		return -ENODEV;
>>  	}
>>  
>>  	if (host->use_dma && host->dma_ops->init)
>> @@ -2976,6 +3064,9 @@ int dw_mci_resume(struct dw_mci *host)
>>  	/* Now that slots are all setup, we can enable card detect */
>>  	dw_mci_enable_cd(host);
>>  
>> +	pm_runtime_mark_last_busy(host->dev);
>> +	pm_runtime_put_autosuspend(host->dev);
>> +
>>  	return 0;
>>  }
>>  EXPORT_SYMBOL(dw_mci_resume);
>> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
>> index d239867..2317f4b7 100644
>> --- a/drivers/mmc/host/dw_mmc.h
>> +++ b/drivers/mmc/host/dw_mmc.h
>> @@ -209,6 +209,8 @@ extern int dw_mci_suspend(struct dw_mci *host);
>>  extern int dw_mci_resume(struct dw_mci *host);
>>  #endif
>>  
>> +#define DWMMC_AUTOSUSPEND_DELAY 50
>> +
>>  /**
>>   * struct dw_mci_slot - MMC slot state
>>   * @mmc: The mmc_host representing this slot.
>>
> 
>