brcmfmac: reset SDIO bus on a firmware crash

commit 4684997d ("brcmfmac: reset PCIe bus on a firmware crash")
adds a reset function to recover firmware trap for PCIe bus. This commit
adds an implementation for SDIO bus.

Upon SDIO firmware trap, do below:
 - Remove the device
 - Reset hardware
 - Probe the device again
Signed-off-by: Chi-Hsien Lin <chi-hsien.lin@cypress.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200622144851.165248-1-chi-hsien.lin@cypress.com

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

@@ -863,7 +863,7 @@ static void brcmf_sdiod_freezer_detach(struct brcmf_sdio_dev *sdiodev)
 }
 #endif /* CONFIG_PM_SLEEP */
 
-static int brcmf_sdiod_remove(struct brcmf_sdio_dev *sdiodev)
+int brcmf_sdiod_remove(struct brcmf_sdio_dev *sdiodev)
 {
 	sdiodev->state = BRCMF_SDIOD_DOWN;
 	if (sdiodev->bus) {
@@ -898,7 +898,7 @@ static void brcmf_sdiod_host_fixup(struct mmc_host *host)
 	host->caps |= MMC_CAP_NONREMOVABLE;
 }
 
-static int brcmf_sdiod_probe(struct brcmf_sdio_dev *sdiodev)
+int brcmf_sdiod_probe(struct brcmf_sdio_dev *sdiodev)
 {
 	int ret = 0;
 	unsigned int f2_blksz = SDIO_FUNC2_BLOCKSIZE;

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

@@ -16,6 +16,7 @@
 #include <linux/mmc/sdio_ids.h>
 #include <linux/mmc/sdio_func.h>
 #include <linux/mmc/card.h>
+#include <linux/mmc/core.h>
 #include <linux/semaphore.h>
 #include <linux/firmware.h>
 #include <linux/module.h>
@@ -4126,6 +4127,36 @@ int brcmf_sdio_get_fwname(struct device *dev, const char *ext, u8 *fw_name)
 	return 0;
 }
 
+static int brcmf_sdio_bus_reset(struct device *dev)
+{
+	int ret = 0;
+	struct brcmf_bus *bus_if = dev_get_drvdata(dev);
+	struct brcmf_sdio_dev *sdiodev = bus_if->bus_priv.sdio;
+
+	brcmf_dbg(SDIO, "Enter\n");
+
+	/* start by unregistering irqs */
+	brcmf_sdiod_intr_unregister(sdiodev);
+
+	brcmf_sdiod_remove(sdiodev);
+
+	/* reset the adapter */
+	sdio_claim_host(sdiodev->func1);
+	mmc_hw_reset(sdiodev->func1->card->host);
+	sdio_release_host(sdiodev->func1);
+
+	brcmf_bus_change_state(sdiodev->bus_if, BRCMF_BUS_DOWN);
+
+	ret = brcmf_sdiod_probe(sdiodev);
+	if (ret) {
+		brcmf_err("Failed to probe after sdio device reset: ret %d\n",
+			  ret);
+		brcmf_sdiod_remove(sdiodev);
+	}
+
+	return ret;
+}
+
 static const struct brcmf_bus_ops brcmf_sdio_bus_ops = {
 	.stop = brcmf_sdio_bus_stop,
 	.preinit = brcmf_sdio_bus_preinit,
@@ -4137,7 +4168,8 @@ static const struct brcmf_bus_ops brcmf_sdio_bus_ops = {
 	.get_ramsize = brcmf_sdio_bus_get_ramsize,
 	.get_memdump = brcmf_sdio_bus_get_memdump,
 	.get_fwname = brcmf_sdio_get_fwname,
-	.debugfs_create = brcmf_sdio_debugfs_create
+	.debugfs_create = brcmf_sdio_debugfs_create,
+	.reset = brcmf_sdio_bus_reset
 };
 
 #define BRCMF_SDIO_FW_CODE	0

drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h

@@ -367,6 +367,9 @@ static inline void brcmf_sdiod_freezer_uncount(struct brcmf_sdio_dev *sdiodev)
 }
 #endif /* CONFIG_PM_SLEEP */
 
+int brcmf_sdiod_probe(struct brcmf_sdio_dev *sdiodev);
+int brcmf_sdiod_remove(struct brcmf_sdio_dev *sdiodev);
+
 struct brcmf_sdio *brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev);
 void brcmf_sdio_remove(struct brcmf_sdio *bus);
 void brcmf_sdio_isr(struct brcmf_sdio *bus);