mmc: host: sdhci-esdhc-imx: refactor the system PM logic

Current suspend/resume logic has one issue. In suspend, will config
register when call sdhci_suspend_host(), but at this time, can't
guarantee host in runtime resume state. If not, the per clock is gate
off, access register will hang.

In sdhci_esdhc_suspend/sdhci_esdhc_resume, remove sdhci_suspend_host()
and sdhci_resume_host(), all are handled in runtime PM callbacks except
the wakeup irq setting. For wakeup irq setting, use pm_runtime_get_sync()
in sdhci_esdhc_suspend() to make sure clock gate on.

Remove pinctrl_pm_select_default_state() in sdhci_esdhc_resume, because
pm_runtime_force_resume() already config the pinctrl state according to
ios timing, and here config the default pinctrl state again is wrong for
SDIO3.0 device if it keep power in suspend.

Signed-off-by: Haibo Chen <[email protected]>
Signed-off-by: Luke Wang <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ulf Hansson <[email protected]>

Author: Luke Wang

drivers/mmc/host/sdhci-esdhc-imx.c

@@ -2009,21 +2009,21 @@ static int sdhci_esdhc_suspend(struct device *dev)
 	struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
 	int ret;
 
-	if (host->mmc->caps2 & MMC_CAP2_CQE) {
-		ret = cqhci_suspend(host->mmc);
-		if (ret)
-			return ret;
-	}
+	/*
+	 * Switch to runtime resume for two reasons:
+	 * 1, there is register access (e.g., wakeup control register), so
+	 *    need to make sure gate on ipg clock.
+	 * 2, make sure the pm_runtime_force_resume() in sdhci_esdhc_resume() really
+	 *    invoke its ->runtime_resume callback (needs_force_resume = 1).
+	 */
+	pm_runtime_get_sync(dev);
 
 	if ((imx_data->socdata->flags & ESDHC_FLAG_STATE_LOST_IN_LPMODE) &&
 		(host->tuning_mode != SDHCI_TUNING_MODE_1)) {
 		mmc_retune_timer_stop(host->mmc);
 		mmc_retune_needed(host->mmc);
 	}
 
-	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
-		mmc_retune_needed(host->mmc);
-
 	/*
 	 * For the device need to keep power during system PM, need
 	 * to save the tuning delay value just in case the usdhc
@@ -2033,16 +2033,26 @@ static int sdhci_esdhc_suspend(struct device *dev)
 	    esdhc_is_usdhc(imx_data))
 		sdhc_esdhc_tuning_save(host);
 
-	ret = sdhci_suspend_host(host);
-	if (ret)
-		return ret;
+	if (device_may_wakeup(dev)) {
+		/* The irqs of imx are not shared. It is safe to disable */
+		disable_irq(host->irq);
+		ret = sdhci_enable_irq_wakeups(host);
+		if (!ret)
+			dev_warn(dev, "Failed to enable irq wakeup\n");
+	}
 
 	ret = pinctrl_pm_select_sleep_state(dev);
 	if (ret)
 		return ret;
 
 	ret = mmc_gpio_set_cd_wake(host->mmc, true);
 
+	/*
+	 * Make sure invoke runtime_suspend to gate off clock.
+	 * uSDHC IP supports in-band SDIO wakeup even without clock.
+	 */
+	pm_runtime_force_suspend(dev);
+
 	return ret;
 }
 
@@ -2053,16 +2063,19 @@ static int sdhci_esdhc_resume(struct device *dev)
 	struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
 	int ret;
 
-	ret = pinctrl_pm_select_default_state(dev);
+	pm_runtime_force_resume(dev);
+
+	ret = mmc_gpio_set_cd_wake(host->mmc, false);
 	if (ret)
 		return ret;
 
 	/* re-initialize hw state in case it's lost in low power mode */
 	sdhci_esdhc_imx_hwinit(host);
 
-	ret = sdhci_resume_host(host);
-	if (ret)
-		return ret;
+	if (host->irq_wake_enabled) {
+		sdhci_disable_irq_wakeups(host);
+		enable_irq(host->irq);
+	}
 
 	/*
 	 * restore the saved tuning delay value for the device which keep
@@ -2072,11 +2085,8 @@ static int sdhci_esdhc_resume(struct device *dev)
 	    esdhc_is_usdhc(imx_data))
 		sdhc_esdhc_tuning_restore(host);
 
-	if (host->mmc->caps2 & MMC_CAP2_CQE)
-		ret = cqhci_resume(host->mmc);
-
-	if (!ret)
-		ret = mmc_gpio_set_cd_wake(host->mmc, false);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
 
 	return ret;
 }