wifi: brcmfmac: keep power during suspend if board requires it

After commit 92caded ("brcmfmac: Avoid keeping power to SDIO card
unless WOWL is used"), the wifi adapter by default is turned off on
suspend and then re-probed on resume.

This conflicts with some embedded boards that require to remain powered.
They will fail on resume with:

brcmfmac: brcmf_sdio_bus_rxctl: resumed on timeout
ieee80211 phy1: brcmf_bus_started: failed: -110
ieee80211 phy1: brcmf_attach: dongle is not responding: err=-110
brcmfmac: brcmf_sdio_firmware_callback: brcmf_attach failed

This commit checks for the Device Tree property 'cap-power-off-cards'.
If this property is not set, it means that we do not have the capability
to power off and should therefore remain powered.

Signed-off-by: Matthias Proske <email@matthias-proske.de>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Link: https://patch.msgid.link/20250212185941.146958-2-email@matthias-proske.de
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Author: matproske

drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c

@@ -1172,26 +1172,31 @@ static int brcmf_ops_sdio_suspend(struct device *dev)
 	struct brcmf_bus *bus_if;
 	struct brcmf_sdio_dev *sdiodev;
 	mmc_pm_flag_t sdio_flags;
+	bool cap_power_off;
 	int ret = 0;
 
 	func = container_of(dev, struct sdio_func, dev);
 	brcmf_dbg(SDIO, "Enter: F%d\n", func->num);
 	if (func->num != 1)
 		return 0;
 
+	cap_power_off = !!(func->card->host->caps & MMC_CAP_POWER_OFF_CARD);
 
 	bus_if = dev_get_drvdata(dev);
 	sdiodev = bus_if->bus_priv.sdio;
 
-	if (sdiodev->wowl_enabled) {
+	if (sdiodev->wowl_enabled || !cap_power_off) {
 		brcmf_sdiod_freezer_on(sdiodev);
 		brcmf_sdio_wd_timer(sdiodev->bus, 0);
 
 		sdio_flags = MMC_PM_KEEP_POWER;
-		if (sdiodev->settings->bus.sdio.oob_irq_supported)
-			enable_irq_wake(sdiodev->settings->bus.sdio.oob_irq_nr);
-		else
-			sdio_flags |= MMC_PM_WAKE_SDIO_IRQ;
+
+		if (sdiodev->wowl_enabled) {
+			if (sdiodev->settings->bus.sdio.oob_irq_supported)
+				enable_irq_wake(sdiodev->settings->bus.sdio.oob_irq_nr);
+			else
+				sdio_flags |= MMC_PM_WAKE_SDIO_IRQ;
+		}
 
 		if (sdio_set_host_pm_flags(sdiodev->func1, sdio_flags))
 			brcmf_err("Failed to set pm_flags %x\n", sdio_flags);
@@ -1213,18 +1218,19 @@ static int brcmf_ops_sdio_resume(struct device *dev)
 	struct brcmf_sdio_dev *sdiodev = bus_if->bus_priv.sdio;
 	struct sdio_func *func = container_of(dev, struct sdio_func, dev);
 	int ret = 0;
+	bool cap_power_off = !!(func->card->host->caps & MMC_CAP_POWER_OFF_CARD);
 
 	brcmf_dbg(SDIO, "Enter: F%d\n", func->num);
 	if (func->num != 2)
 		return 0;
 
-	if (!sdiodev->wowl_enabled) {
+	if (!sdiodev->wowl_enabled && cap_power_off) {
 		/* bus was powered off and device removed, probe again */
 		ret = brcmf_sdiod_probe(sdiodev);
 		if (ret)
 			brcmf_err("Failed to probe device on resume\n");
 	} else {
-		if (sdiodev->settings->bus.sdio.oob_irq_supported)
+		if (sdiodev->wowl_enabled && sdiodev->settings->bus.sdio.oob_irq_supported)
 			disable_irq_wake(sdiodev->settings->bus.sdio.oob_irq_nr);
 
 		brcmf_sdiod_freezer_off(sdiodev);