[PATCH v2] mmc: sdhci-of-dwcmshc: Add runtime PM operations for BlueField-3

Liming Sun
2023-05-12T12:21:23Z

This commit implements the runtime PM operations for BlueField-3 SoC
to disable eMMC card clock when idle.

Signed-off-by: Liming Sun <limings@nvidia.com>
---
v1->v2:
Updates for comments from Ulf:
- Make the runtime PM logic generic for sdhci-of-dwcmshc;
v1: Initial version.
---
drivers/mmc/host/sdhci-of-dwcmshc.c | 56 ++++++++++++++++++++++++++++-
1 file changed, 55 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
index e68cd87998c8..a3277f4d250d 100644
--- a/drivers/mmc/host/sdhci-of-dwcmshc.c
+++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
@@ -15,6 +15,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/sizes.h>

@@ -546,6 +547,8 @@ static int dwcmshc_probe(struct platform_device *pdev)
sdhci_enable_v4_mode(host);
#endif

+ pm_runtime_enable(dev);
+
host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;

err = sdhci_setup_host(host);
@@ -646,7 +649,58 @@ static int dwcmshc_resume(struct device *dev)
}
#endif

-static SIMPLE_DEV_PM_OPS(dwcmshc_pmops, dwcmshc_suspend, dwcmshc_resume);
+#ifdef CONFIG_PM
+
+#ifdef CONFIG_ACPI
+static void dwcmshc_enable_card_clk(struct sdhci_host *host)
+{
+ u16 ctrl;
+
+ ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+ ctrl |= SDHCI_CLOCK_CARD_EN;
+ sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
+}
+
+static void dwcmshc_disable_card_clk(struct sdhci_host *host)
+{
+ u16 ctrl;
+
+ ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+ ctrl &= ~SDHCI_CLOCK_CARD_EN;
+ sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
+}
+#endif
+
+static int dwcmshc_runtime_suspend(struct device *dev)
+{
+ struct sdhci_host *host = dev_get_drvdata(dev);
+ int ret = 0;
+
+ ret = sdhci_runtime_suspend_host(host);
+ if (!ret)
+ dwcmshc_disable_card_clk(host);
+
+ return ret;
+}
+
+static int dwcmshc_runtime_resume(struct device *dev)
+{
+ struct sdhci_host *host = dev_get_drvdata(dev);
+ int ret = 0;
+
+ dwcmshc_enable_card_clk(host);
+ ret = sdhci_runtime_resume_host(host, 0);
+
+ return ret;
+}
+
+#endif
+
+static const struct dev_pm_ops dwcmshc_pmops = {
+ SET_SYSTEM_SLEEP_PM_OPS(dwcmshc_suspend, dwcmshc_resume)
+ SET_RUNTIME_PM_OPS(dwcmshc_runtime_suspend,
+ dwcmshc_runtime_resume, NULL)
+};

static struct platform_driver sdhci_dwcmshc_driver = {
.driver = {
--
2.30.1