greybus: interface: move boot-status clearing to interface enable

Reading and clearing the boot status of an interface is an interface
operation and belongs in the interface code.

As part of the reworked interface boot sequence, we also want to do this
when enabling (enumerating) a Greybus interface.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/drivers/staging/greybus/interface.c b/drivers/staging/greybus/interface.c
index 44226c4..deb5b26 100644
--- a/drivers/staging/greybus/interface.c
+++ b/drivers/staging/greybus/interface.c
@@ -9,6 +9,69 @@
 
 #include "greybus.h"
 
+
+/*
+ * T_TstSrcIncrement is written by the module on ES2 as a stand-in for boot
+ * status attribute ES3_INIT_STATUS. AP needs to read and clear it, after
+ * reading a non-zero value from it.
+ *
+ * FIXME: This is module-hardware dependent and needs to be extended for every
+ * type of module we want to support.
+ */
+static int gb_interface_read_and_clear_boot_status(struct gb_interface *intf)
+{
+	struct gb_host_device *hd = intf->hd;
+	int ret;
+	u32 value;
+	u16 attr;
+	u8 init_status;
+
+	/*
+	 * Check if the module is ES2 or ES3, and choose attr number
+	 * appropriately.
+	 * FIXME: Remove ES2 support from the kernel entirely.
+	 */
+	if (intf->ddbl1_manufacturer_id == ES2_DDBL1_MFR_ID &&
+				intf->ddbl1_product_id == ES2_DDBL1_PROD_ID)
+		attr = DME_ATTR_T_TST_SRC_INCREMENT;
+	else
+		attr = DME_ATTR_ES3_INIT_STATUS;
+
+	/* Read and clear boot status in ES3_INIT_STATUS */
+	ret = gb_svc_dme_peer_get(hd->svc, intf->interface_id, attr,
+				  DME_ATTR_SELECTOR_INDEX, &value);
+	if (ret)
+		return ret;
+
+	/*
+	 * A nonzero boot status indicates the module has finished
+	 * booting. Clear it.
+	 */
+	if (!value) {
+		dev_err(&intf->dev, "Module not ready yet\n");
+		return -ENODEV;
+	}
+
+	/*
+	 * Check if the module needs to boot from UniPro.
+	 * For ES2: We need to check lowest 8 bits of 'value'.
+	 * For ES3: We need to check highest 8 bits out of 32 of 'value'.
+	 * FIXME: Remove ES2 support from the kernel entirely.
+	 */
+	if (intf->ddbl1_manufacturer_id == ES2_DDBL1_MFR_ID &&
+			intf->ddbl1_product_id == ES2_DDBL1_PROD_ID)
+		init_status = value;
+	else
+		init_status = value >> 24;
+
+	if (init_status == DME_DIS_UNIPRO_BOOT_STARTED ||
+			init_status == DME_DIS_FALLBACK_UNIPRO_BOOT_STARTED)
+		intf->boot_over_unipro = true;
+
+	return gb_svc_dme_peer_set(hd->svc, intf->interface_id, attr,
+				   DME_ATTR_SELECTOR_INDEX, 0);
+}
+
 /* interface sysfs attributes */
 #define gb_interface_attr(field, type)					\
 static ssize_t field##_show(struct device *dev,				\
@@ -147,6 +210,12 @@ int gb_interface_enable(struct gb_interface *intf)
 	int ret, size;
 	void *manifest;
 
+	ret = gb_interface_read_and_clear_boot_status(intf);
+	if (ret) {
+		dev_err(&intf->dev, "failed to clear boot status: %d\n", ret);
+		return ret;
+	}
+
 	/* Establish control connection */
 	ret = gb_control_enable(intf->control);
 	if (ret)