[PATCH v3 1/2] arm: rpi: Add function to trigger VL805's firmware load

From: Nicolas Saenz Julienne
Date: Tue May 05 2020 - 12:26:29 EST


On the Raspberry Pi 4, after a PCI reset, VL805's (a xHCI chip) firmware
may either be loaded directly from an EEPROM or, if not present, by the
SoC's VideCore (the SoC's co-processor). Introduce the function that
informs VideCore that VL805 may need its firmware loaded.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>

---
Changes since v2:
- Correct wrong function name in comment
- Add better comment on rpi_firmware_init_vl805()

Changes since v1:
- Rename function so it's not mistaken with regular firmware loading

arch/arm/mach-bcm283x/include/mach/mbox.h | 13 +++++++
arch/arm/mach-bcm283x/include/mach/msg.h | 7 ++++
arch/arm/mach-bcm283x/msg.c | 45 +++++++++++++++++++++++
3 files changed, 65 insertions(+)

diff --git a/arch/arm/mach-bcm283x/include/mach/mbox.h b/arch/arm/mach-bcm283x/include/mach/mbox.h
index 60e226ce1d..2ae2d3d97c 100644
--- a/arch/arm/mach-bcm283x/include/mach/mbox.h
+++ b/arch/arm/mach-bcm283x/include/mach/mbox.h
@@ -491,6 +491,19 @@ struct bcm2835_mbox_tag_set_palette {
} body;
};

+#define BCM2835_MBOX_TAG_NOTIFY_XHCI_RESET 0x00030058
+
+struct bcm2835_mbox_tag_pci_dev_addr {
+ struct bcm2835_mbox_tag_hdr tag_hdr;
+ union {
+ struct {
+ u32 dev_addr;
+ } req;
+ struct {
+ } resp;
+ } body;
+};
+
/*
* Pass a raw u32 message to the VC, and receive a raw u32 back.
*
diff --git a/arch/arm/mach-bcm283x/include/mach/msg.h b/arch/arm/mach-bcm283x/include/mach/msg.h
index 4afb08631b..f5213dd0e0 100644
--- a/arch/arm/mach-bcm283x/include/mach/msg.h
+++ b/arch/arm/mach-bcm283x/include/mach/msg.h
@@ -48,4 +48,11 @@ int bcm2835_set_video_params(int *widthp, int *heightp, int depth_bpp,
int pixel_order, int alpha_mode, ulong *fb_basep,
ulong *fb_sizep, int *pitchp);

+/**
+ * bcm2711_notify_vl805_reset() - get vl805's firmware loaded
+ *
+ * @return 0 if OK, -EIO on error
+ */
+int bcm2711_notify_vl805_reset(void);
+
#endif
diff --git a/arch/arm/mach-bcm283x/msg.c b/arch/arm/mach-bcm283x/msg.c
index 94b75283f8..f8ef531652 100644
--- a/arch/arm/mach-bcm283x/msg.c
+++ b/arch/arm/mach-bcm283x/msg.c
@@ -40,6 +40,12 @@ struct msg_setup {
u32 end_tag;
};

+struct msg_notify_vl805_reset {
+ struct bcm2835_mbox_hdr hdr;
+ struct bcm2835_mbox_tag_pci_dev_addr dev_addr;
+ u32 end_tag;
+};
+
int bcm2835_power_on_module(u32 module)
{
ALLOC_CACHE_ALIGN_BUFFER(struct msg_set_power_state, msg_pwr, 1);
@@ -151,3 +157,42 @@ int bcm2835_set_video_params(int *widthp, int *heightp, int depth_bpp,

return 0;
}
+
+/*
+ * The Raspberry Pi 4 gets its USB functionality from VL805, a PCIe chip that
+ * implements xHCI. After a PCI reset, VL805's firmware may either be loaded
+ * directly from an EEPROM or, if not present, by the SoC's co-processor,
+ * VideoCore. RPi4's VideoCore OS contains both the non public firmware load
+ * logic and the VL805 firmware blob. This function triggers the aforementioned
+ * process.
+ */
+int bcm2711_notify_vl805_reset(void)
+{
+ ALLOC_CACHE_ALIGN_BUFFER(struct msg_notify_vl805_reset,
+ msg_notify_vl805_reset, 1);
+ int ret;
+
+ BCM2835_MBOX_INIT_HDR(msg_notify_vl805_reset);
+ BCM2835_MBOX_INIT_TAG(&msg_notify_vl805_reset->dev_addr,
+ NOTIFY_XHCI_RESET);
+
+ /*
+ * The pci device address is expected like this:
+ *
+ * PCI_BUS << 20 | PCI_SLOT << 15 | PCI_FUNC << 12
+ *
+ * But since RPi4's PCIe setup is hardwired, we know the address in
+ * advance.
+ */
+ msg_notify_vl805_reset->dev_addr.body.req.dev_addr = 0x100000;
+
+ ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN,
+ &msg_notify_vl805_reset->hdr);
+ if (ret) {
+ printf("bcm2711: Faild to load vl805's firmware, %d\n", ret);
+ return -EIO;
+ }
+
+ return 0;
+}
+
--
2.26.2