[R-6.0.3] qm35: fix kernel driver

Fixes:
* fix race condition between the enabling/disabling of the regulators
  and the HSSPI start/stop by enabling regulators then start HSSPI, stop
  HSSPI then disable regulators
* add support of vdd4
* assert reset line when regulators are off
* add robustness for floating MISO

Bug: 254111407
Bug: 266966191
Change-Id: Id285988542ffa9b57f3e8c1b165fc6b2e0635e55
Signed-off-by: Philippe Skowronski <philippe.skowronski@qorvo.com>

4 files changed, 62 insertions, 15 deletions

diff --git a/debug_qmrom.c b/debug_qmrom.c
index 9fbd6a4..8c77bd3 100644
--- a/debug_qmrom.c
+++ b/debug_qmrom.c
@@ -262,7 +262,8 @@ static ssize_t rom_flash_fw(struct file *filp, const char __user *buff,
 		goto end;
 	}
 
-	pr_info("Flashing image %s (%pK->data %pK)...\n", filename, fw, fw->data);
+	pr_info("Flashing image %s (%pK->data %pK)...\n", filename, fw,
+		fw->data);
 
 	h = qmrom_init(&qm35_hdl->spi->dev, qm35_hdl, qm35_hdl->gpio_ss_rdy,
 		       QMROM_RETRIES, qmrom_spi_reset_device);
diff --git a/hsspi.c b/hsspi.c
index 0be5a94..ad0d6ea 100644
--- a/hsspi.c
+++ b/hsspi.c
@@ -249,7 +249,8 @@ static int spi_xfer(struct hsspi *hsspi, const void *tx, void *rx,
 			continue;
 		}
 
-		if (!(hsspi->soc->flags & STC_SOC_RDY)) {
+		if (!(hsspi->soc->flags & STC_SOC_RDY) ||
+		    (hsspi->soc->flags == 0xff)) {
 			dev_err(&hsspi->spi->dev,
 				"FW not ready (flags %#02x)\n",
 				hsspi->soc->flags);
diff --git a/qm35-spi.c b/qm35-spi.c
index 45203f5..69efabf 100644
--- a/qm35-spi.c
+++ b/qm35-spi.c
@@ -57,6 +57,7 @@
 
 #define QM35_REGULATOR_DELAY_US 1000
 #define QMROM_RETRIES 10
+#define REGULATORS_ENABLED(x) (x->vdd1 || x->vdd2 || x->vdd3 || x->vdd4)
 
 static int qm_firmware_load(struct qm35_ctx *qm35_hdl);
 static void qm35_regulators_set(struct qm35_ctx *qm35_hdl, bool on);
@@ -105,6 +106,12 @@ int log_qm_traces = 1;
 module_param(log_qm_traces, int, 0444);
 MODULE_PARM_DESC(log_qm_traces, "Logs the QM35 traces in the kernel messages");
 
+bool reset_when_disabled = true;
+module_param(reset_when_disabled, bool, 0444);
+MODULE_PARM_DESC(
+	reset_when_disabled,
+	"Assert reset line when UWB is disabled (if at least one regulator is defined in DTS)");
+
 static uint8_t qm_soc_id[ROM_SOC_ID_LEN];
 static uint16_t qm_dev_id;
 
@@ -183,17 +190,23 @@ static long uci_ioctl(struct file *filp, unsigned int cmd, unsigned long args)
 
 		qm35_hsspi_stop(qm35_hdl);
 
+		if (REGULATORS_ENABLED(qm35_hdl))
+			qm35_regulators_set(qm35_hdl, on);
+
 		/*
-		 * If there is no regulators, just reset the QM
+		 * Always reset QM as regulators could be shared with
+		 * other devices and power may not be controlled as
+		 * expected
 		 */
-		if (qm35_hdl->vdd1 || qm35_hdl->vdd2 || qm35_hdl->vdd3)
-			qm35_regulators_set(qm35_hdl, on);
-		else
-			ret = qm35_reset(qm35_hdl, QM_RESET_LOW_MS);
+		if (!reset_when_disabled)
+			qm35_reset(qm35_hdl, QM_RESET_LOW_MS);
 
 		msleep(QM_BOOT_MS);
 
-		qm35_hsspi_start(qm35_hdl);
+		/* if reset or power on */
+		if (!REGULATORS_ENABLED(qm35_hdl) ||
+		    (REGULATORS_ENABLED(qm35_hdl) && on))
+			qm35_hsspi_start(qm35_hdl);
 
 		return 0;
 	}
@@ -384,6 +397,10 @@ void qm35_hsspi_start(struct qm35_ctx *qm35_hdl)
 {
 	int irq;
 
+	/* nothing to do as HSSPI is already started */
+	if (qm35_hdl->hsspi.state == HSSPI_RUNNING)
+		return;
+
 	irq = gpiod_to_irq(qm35_hdl->gpio_ss_rdy);
 	if (irq >= 0) {
 		enable_irq(irq);
@@ -410,6 +427,10 @@ void qm35_hsspi_stop(struct qm35_ctx *qm35_hdl)
 {
 	int irq;
 
+	/* nothing to do as HSSPI is already stopped */
+	if (qm35_hdl->hsspi.state == HSSPI_STOPPED)
+		return;
+
 	hsspi_stop(&qm35_hdl->hsspi);
 
 	irq = gpiod_to_irq(qm35_hdl->gpio_ss_rdy);
@@ -633,6 +654,14 @@ static void qm35_regulators_set(struct qm35_ctx *qm35_hdl, bool on)
 	if (is_enabled == on)
 		return;
 
+	if (reset_when_disabled && !on &&
+	    qm35_get_state(qm35_hdl) != QM35_CTRL_STATE_RESET) {
+		if (qm35_hdl->gpio_reset) {
+			gpiod_set_value(qm35_hdl->gpio_reset, 1);
+		}
+		qm35_set_state(qm35_hdl, QM35_CTRL_STATE_RESET);
+	}
+
 	ret = qm35_regulator_set_one(qm35_hdl->vdd1, on);
 	if (ret)
 		dev_err(dev, str_fmt, on_str, "vdd1", ret);
@@ -645,14 +674,27 @@ static void qm35_regulators_set(struct qm35_ctx *qm35_hdl, bool on)
 	if (ret)
 		dev_err(dev, str_fmt, on_str, "vdd3", ret);
 
+	ret = qm35_regulator_set_one(qm35_hdl->vdd4, on);
+	if (ret)
+		dev_err(dev, str_fmt, on_str, "vdd4", ret);
+
 	/* wait for regulator stabilization */
 	usleep_range(QM35_REGULATOR_DELAY_US, QM35_REGULATOR_DELAY_US + 100);
+
+	if (reset_when_disabled && on &&
+	    qm35_get_state(qm35_hdl) == QM35_CTRL_STATE_RESET) {
+		if (qm35_hdl->gpio_reset) {
+			gpiod_set_value(qm35_hdl->gpio_reset, 0);
+		}
+		qm35_set_state(qm35_hdl, QM35_CTRL_STATE_UNKNOWN);
+	}
 }
 
 static void qm35_regulators_setup_one(struct regulator **reg,
 				      struct device *dev, const char *name)
 {
-	static const char *str_fmt = "failed to get %s regulator: %d\n";
+	static const char *str_fmt =
+		"%s regulator not defined in device tree: %d\n";
 	struct regulator *tmp;
 
 	tmp = devm_regulator_get_optional(dev, name);
@@ -670,8 +712,10 @@ static void qm35_regulators_setup(struct qm35_ctx *qm35_hdl)
 	qm35_regulators_setup_one(&qm35_hdl->vdd1, dev, "qm35-vdd1");
 	qm35_regulators_setup_one(&qm35_hdl->vdd2, dev, "qm35-vdd2");
 	qm35_regulators_setup_one(&qm35_hdl->vdd3, dev, "qm35-vdd3");
+	qm35_regulators_setup_one(&qm35_hdl->vdd4, dev, "qm35-vdd4");
 
 	qm35_hdl->regulators_enabled = false;
+	qm35_hdl->state = QM35_CTRL_STATE_RESET;
 }
 
 static int qm35_probe(struct spi_device *spi)
@@ -715,17 +759,12 @@ static int qm35_probe(struct spi_device *spi)
 
 	qm35_regulators_setup(qm35_ctx);
 
-	/* power on */
-	qm35_regulators_set(qm35_ctx, true);
-
 	uci_misc = &qm35_ctx->uci_dev;
 	uci_misc->minor = MISC_DYNAMIC_MINOR;
 	uci_misc->name = UCI_DEV_NAME;
 	uci_misc->fops = &uci_fops;
 	uci_misc->parent = &spi->dev;
 
-	qm35_ctx->state = QM35_CTRL_STATE_UNKNOWN;
-
 	/* we need the debugfs root initialized here to be able
 	 * to display the soc info populated if flash_on_probe
 	 * is set for chips different than A0
@@ -776,14 +815,19 @@ static int qm35_probe(struct spi_device *spi)
 		goto log_layer_unregister;
 
 	if (flash_on_probe) {
+		qm35_regulators_set(qm35_ctx, true);
 		ret = qm_firmware_load(qm35_ctx);
+		qm35_regulators_set(qm35_ctx, false);
 		if (ret)
 			goto log_layer_unregister;
 	}
 
 	hsspi_set_gpios(&qm35_ctx->hsspi, qm35_ctx->gpio_ss_rdy,
 			qm35_ctx->gpio_exton);
-	hsspi_start(&qm35_ctx->hsspi);
+
+	/* If regulators not available, QM is powered on */
+	if (!REGULATORS_ENABLED(qm35_ctx))
+		hsspi_start(&qm35_ctx->hsspi);
 
 	ret = misc_register(&qm35_ctx->uci_dev);
 	if (ret) {
diff --git a/qm35.h b/qm35.h
index beae5ab..5886270 100644
--- a/qm35.h
+++ b/qm35.h
@@ -52,6 +52,7 @@ struct qm35_ctx {
 	struct regulator *vdd1;
 	struct regulator *vdd2;
 	struct regulator *vdd3;
+	struct regulator *vdd4;
 	bool regulators_enabled;
 	bool log_qm_traces;
 };