linux-kernel - [PATCH 4/5] wifi: wfx: allow SDIO device to wake up the host

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Message-Id: <20250228171441.109321-5-jerome.pouiller@silabs.com>
Date: Fri, 28 Feb 2025 18:14:40 +0100
From: Jérôme Pouiller <jerome.pouiller@...abs.com>
To: linux-wireless@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, Kalle Valo <kvalo@...nel.org>,
        linux-devel@...abs.com,
        Jérôme Pouiller <jerome.pouiller@...abs.com>
Subject: [PATCH 4/5] wifi: wfx: allow SDIO device to wake up the host

If the device is connected with SDIO bus, it can wake up the host using
either the SDIO controller (that requires MMC_PM_WAKE_SDIO_IRQ
capability) or the out-of-bound IRQ. This patch allows both.

Obviously, the SDIO controller must be able to keep the SDIO device
powered on.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@...abs.com>
---
 drivers/net/wireless/silabs/wfx/bus_sdio.c | 44 ++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/drivers/net/wireless/silabs/wfx/bus_sdio.c b/drivers/net/wireless/silabs/wfx/bus_sdio.c
index f290eecde773..bd8e1ffb61bb 100644
--- a/drivers/net/wireless/silabs/wfx/bus_sdio.c
+++ b/drivers/net/wireless/silabs/wfx/bus_sdio.c
@@ -14,6 +14,7 @@
 #include <linux/of_irq.h>
 #include <linux/irq.h>
 #include <linux/align.h>
+#include <linux/pm.h>
 
 #include "bus.h"
 #include "wfx.h"
@@ -191,9 +192,46 @@ static const struct of_device_id wfx_sdio_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, wfx_sdio_of_match);
 
+static int wfx_sdio_suspend(struct device *dev)
+{
+	struct sdio_func *func = dev_to_sdio_func(dev);
+	struct wfx_sdio_priv *bus = sdio_get_drvdata(func);
+	int ret;
+
+	if (!device_may_wakeup(dev))
+		return 0;
+
+	flush_work(&bus->core->hif.bh);
+	// Either "wakeup-source" attribute or out-of-band IRQ is required for WoWLAN
+	if (bus->of_irq) {
+		ret = enable_irq_wake(bus->of_irq);
+		if (ret)
+			return ret;
+	} else {
+		ret = sdio_set_host_pm_flags(func, MMC_PM_WAKE_SDIO_IRQ);
+		if (ret)
+			return ret;
+	}
+	return sdio_set_host_pm_flags(func, MMC_PM_KEEP_POWER);
+}
+
+static int wfx_sdio_resume(struct device *dev)
+{
+	struct sdio_func *func = dev_to_sdio_func(dev);
+	struct wfx_sdio_priv *bus = sdio_get_drvdata(func);
+
+	if (!device_may_wakeup(dev))
+		return 0;
+	if (bus->of_irq)
+		return disable_irq_wake(bus->of_irq);
+	else
+		return 0;
+}
+
 static int wfx_sdio_probe(struct sdio_func *func, const struct sdio_device_id *id)
 {
 	const struct wfx_platform_data *pdata = of_device_get_match_data(&func->dev);
+	mmc_pm_flag_t pm_flag = sdio_get_host_pm_caps(func);
 	struct device_node *np = func->dev.of_node;
 	struct wfx_sdio_priv *bus;
 	int ret;
@@ -235,6 +273,9 @@ static int wfx_sdio_probe(struct sdio_func *func, const struct sdio_device_id *i
 	if (ret)
 		goto sdio_release;
 
+	if (pm_flag & MMC_PM_KEEP_POWER)
+		device_set_wakeup_capable(&func->dev, true);
+
 	return 0;
 
 sdio_release:
@@ -261,6 +302,8 @@ static const struct sdio_device_id wfx_sdio_ids[] = {
 };
 MODULE_DEVICE_TABLE(sdio, wfx_sdio_ids);
 
+DEFINE_SIMPLE_DEV_PM_OPS(wfx_sdio_pm_ops, wfx_sdio_suspend, wfx_sdio_resume);
+
 struct sdio_driver wfx_sdio_driver = {
 	.name = "wfx-sdio",
 	.id_table = wfx_sdio_ids,
@@ -268,5 +311,6 @@ struct sdio_driver wfx_sdio_driver = {
 	.remove = wfx_sdio_remove,
 	.drv = {
 		.of_match_table = wfx_sdio_of_match,
+		.pm = &wfx_sdio_pm_ops,
 	}
 };
-- 
2.39.5