brcmfmac: add a timer to read console periodically in PCIE bus

Currently, host only reads console buffer when receiving mailbox data or
hit crash with PCIE bus. Therefore, we add timer in PCIE code to read
console buffer periodically to help developer and user check firmware
message when there is no data transmission between host and dongle.
Signed-off-by: Wright Feng <wright.feng@cypress.com>
Signed-off-by: Chi-hsien Lin <chi-hsien.lin@cypress.com>
Signed-off-by: Ian Lin <ian.lin@infineon.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220929031001.9962-2-ian.lin@infineon.com

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

@@ -24,6 +24,12 @@
 #define BRCMF_NROF_COMMON_MSGRINGS	(BRCMF_NROF_H2D_COMMON_MSGRINGS + \
 					 BRCMF_NROF_D2H_COMMON_MSGRINGS)
 
+/* The interval to poll console */
+#define BRCMF_CONSOLE	10
+
+/* The maximum console interval value (5 mins) */
+#define MAX_CONSOLE_INTERVAL	(5 * 60)
+
 /* The level of bus communication with the dongle */
 enum brcmf_bus_state {
 	BRCMF_BUS_DOWN,		/* Not ready for frame transfers */

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

@@ -12,6 +12,8 @@
 #include <linux/interrupt.h>
 #include <linux/bcma/bcma.h>
 #include <linux/sched.h>
+#include <linux/sched/signal.h>
+#include <linux/kthread.h>
 #include <linux/io.h>
 #include <asm/unaligned.h>
 
@@ -340,6 +342,11 @@ struct brcmf_pciedev_info {
 			  u16 value);
 	struct brcmf_mp_device *settings;
 	struct brcmf_otp_params otp;
+#ifdef DEBUG
+	u32 console_interval;
+	bool console_active;
+	struct timer_list timer;
+#endif
 };
 
 struct brcmf_pcie_ringbuf {
@@ -440,6 +447,9 @@ static void brcmf_pcie_setup(struct device *dev, int ret,
 			     struct brcmf_fw_request *fwreq);
 static struct brcmf_fw_request *
 brcmf_pcie_prepare_fw_request(struct brcmf_pciedev_info *devinfo);
+static void
+brcmf_pcie_fwcon_timer(struct brcmf_pciedev_info *devinfo, bool active);
+static void brcmf_pcie_debugfs_create(struct device *dev);
 
 static u16
 brcmf_pcie_read_reg16(struct brcmf_pciedev_info *devinfo, u32 reg_offset)
@@ -1413,6 +1423,11 @@ static int brcmf_pcie_init_scratchbuffers(struct brcmf_pciedev_info *devinfo)
 
 static void brcmf_pcie_down(struct device *dev)
 {
+	struct brcmf_bus *bus_if = dev_get_drvdata(dev);
+	struct brcmf_pciedev *pcie_bus_dev = bus_if->bus_priv.pcie;
+	struct brcmf_pciedev_info *devinfo = pcie_bus_dev->devinfo;
+
+	brcmf_pcie_fwcon_timer(devinfo, false);
 }
 
 static int brcmf_pcie_preinit(struct device *dev)
@@ -1547,6 +1562,7 @@ static const struct brcmf_bus_ops brcmf_pcie_bus_ops = {
 	.get_memdump = brcmf_pcie_get_memdump,
 	.get_blob = brcmf_pcie_get_blob,
 	.reset = brcmf_pcie_reset,
+	.debugfs_create = brcmf_pcie_debugfs_create,
 };
 
 
@@ -2123,6 +2139,8 @@ static void brcmf_pcie_setup(struct device *dev, int ret,
 
 	brcmf_pcie_bus_console_read(devinfo, false);
 
+	brcmf_pcie_fwcon_timer(devinfo, true);
+
 	return;
 
 fail:
@@ -2197,6 +2215,105 @@ brcmf_pcie_prepare_fw_request(struct brcmf_pciedev_info *devinfo)
 	return fwreq;
 }
 
+#ifdef DEBUG
+static void
+brcmf_pcie_fwcon_timer(struct brcmf_pciedev_info *devinfo, bool active)
+{
+	if (!active) {
+		if (devinfo->console_active) {
+			del_timer_sync(&devinfo->timer);
+			devinfo->console_active = false;
+		}
+		return;
+	}
+
+	/* don't start the timer */
+	if (devinfo->state != BRCMFMAC_PCIE_STATE_UP ||
+	    !devinfo->console_interval || !BRCMF_FWCON_ON())
+		return;
+
+	if (!devinfo->console_active) {
+		devinfo->timer.expires = jiffies + devinfo->console_interval;
+		add_timer(&devinfo->timer);
+		devinfo->console_active = true;
+	} else {
+		/* Reschedule the timer */
+		mod_timer(&devinfo->timer, jiffies + devinfo->console_interval);
+	}
+}
+
+static void
+brcmf_pcie_fwcon(struct timer_list *t)
+{
+	struct brcmf_pciedev_info *devinfo = from_timer(devinfo, t, timer);
+
+	if (!devinfo->console_active)
+		return;
+
+	brcmf_pcie_bus_console_read(devinfo, false);
+
+	/* Reschedule the timer if console interval is not zero */
+	mod_timer(&devinfo->timer, jiffies + devinfo->console_interval);
+}
+
+static int brcmf_pcie_console_interval_get(void *data, u64 *val)
+{
+	struct brcmf_pciedev_info *devinfo = data;
+
+	*val = devinfo->console_interval;
+
+	return 0;
+}
+
+static int brcmf_pcie_console_interval_set(void *data, u64 val)
+{
+	struct brcmf_pciedev_info *devinfo = data;
+
+	if (val > MAX_CONSOLE_INTERVAL)
+		return -EINVAL;
+
+	devinfo->console_interval = val;
+
+	if (!val && devinfo->console_active)
+		brcmf_pcie_fwcon_timer(devinfo, false);
+	else if (val)
+		brcmf_pcie_fwcon_timer(devinfo, true);
+
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(brcmf_pcie_console_interval_fops,
+			brcmf_pcie_console_interval_get,
+			brcmf_pcie_console_interval_set,
+			"%llu\n");
+
+static void brcmf_pcie_debugfs_create(struct device *dev)
+{
+	struct brcmf_bus *bus_if = dev_get_drvdata(dev);
+	struct brcmf_pub *drvr = bus_if->drvr;
+	struct brcmf_pciedev *pcie_bus_dev = bus_if->bus_priv.pcie;
+	struct brcmf_pciedev_info *devinfo = pcie_bus_dev->devinfo;
+	struct dentry *dentry = brcmf_debugfs_get_devdir(drvr);
+
+	if (IS_ERR_OR_NULL(dentry))
+		return;
+
+	devinfo->console_interval = BRCMF_CONSOLE;
+
+	debugfs_create_file("console_interval", 0644, dentry, devinfo,
+			    &brcmf_pcie_console_interval_fops);
+}
+
+#else
+void brcmf_pcie_fwcon_timer(struct brcmf_pciedev_info *devinfo, bool active)
+{
+}
+
+static void brcmf_pcie_debugfs_create(struct device *dev)
+{
+}
+#endif
+
 static int
 brcmf_pcie_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
@@ -2278,6 +2395,11 @@ brcmf_pcie_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		goto fail_brcmf;
 	}
 
+#ifdef DEBUG
+	/* Set up the fwcon timer */
+	timer_setup(&devinfo->timer, brcmf_pcie_fwcon, 0);
+#endif
+
 	fwreq = brcmf_pcie_prepare_fw_request(devinfo);
 	if (!fwreq) {
 		ret = -ENOMEM;
@@ -2323,6 +2445,7 @@ brcmf_pcie_remove(struct pci_dev *pdev)
 
 	devinfo = bus->bus_priv.pcie->devinfo;
 	brcmf_pcie_bus_console_read(devinfo, false);
+	brcmf_pcie_fwcon_timer(devinfo, false);
 
 	devinfo->state = BRCMFMAC_PCIE_STATE_DOWN;
 	if (devinfo->ci)
@@ -2366,6 +2489,7 @@ static int brcmf_pcie_pm_enter_D3(struct device *dev)
 	bus = dev_get_drvdata(dev);
 	devinfo = bus->bus_priv.pcie->devinfo;
 
+	brcmf_pcie_fwcon_timer(devinfo, false);
 	brcmf_bus_change_state(bus, BRCMF_BUS_DOWN);
 
 	devinfo->mbdata_completed = false;
@@ -2409,6 +2533,7 @@ static int brcmf_pcie_pm_leave_D3(struct device *dev)
 		brcmf_bus_change_state(bus, BRCMF_BUS_UP);
 		brcmf_pcie_intr_enable(devinfo);
 		brcmf_pcie_hostready(devinfo);
+		brcmf_pcie_fwcon_timer(devinfo, true);
 		return 0;
 	}
 

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

@@ -135,8 +135,6 @@ struct rte_console {
 
 #define BRCMF_FIRSTREAD	(1 << 6)
 
-#define BRCMF_CONSOLE	10	/* watchdog interval to poll console */
-
 /* SBSDIO_DEVICE_CTL */
 
 /* 1: device will assert busy signal when receiving CMD53 */