We don't support USB super-speed in U-Boot yet, we lack the SS PHY drivers, however from my testing even with a PHY driver there seem to be other issues when talking to super-speed peripherals.
In pursuit of maintaining upstream DT compatibility, and simplifying porting for new devices, let's implement the DT fixups necessary to configure USB in high-speed only mode at runtime. The pattern is identical for all Qualcomm boards that use the Synaptics DWC3 controller:
* Add an additional property on the Qualcomm wrapper node * Remove the super-speed phy phandle and phy-name entries.
Signed-off-by: Caleb Connolly caleb.connolly@linaro.org --- arch/arm/mach-snapdragon/Makefile | 1 + arch/arm/mach-snapdragon/board.c | 3 + arch/arm/mach-snapdragon/of_fixup.c | 115 +++++++++++++++++++++++++++++++++++ arch/arm/mach-snapdragon/qcom-priv.h | 19 ++++++ 4 files changed, 138 insertions(+)
diff --git a/arch/arm/mach-snapdragon/Makefile b/arch/arm/mach-snapdragon/Makefile index 857171e593da..7a4495c8108f 100644 --- a/arch/arm/mach-snapdragon/Makefile +++ b/arch/arm/mach-snapdragon/Makefile @@ -2,4 +2,5 @@ # # (C) Copyright 2015 Mateusz Kulikowski mateusz.kulikowski@gmail.com
obj-y += board.o +obj-$(CONFIG_OF_LIVE) += of_fixup.o diff --git a/arch/arm/mach-snapdragon/board.c b/arch/arm/mach-snapdragon/board.c index 6f762fc948bf..65e4c61e866a 100644 --- a/arch/arm/mach-snapdragon/board.c +++ b/arch/arm/mach-snapdragon/board.c @@ -27,8 +27,10 @@ #include <fdt_support.h> #include <usb.h> #include <sort.h>
+#include "qcom-priv.h" + DECLARE_GLOBAL_DATA_PTR;
static struct mm_region rbx_mem_map[CONFIG_NR_DRAM_BANKS + 2] = { { 0 } };
@@ -159,8 +161,9 @@ void __weak qcom_board_init(void)
int board_init(void) { show_psci_version(); + qcom_of_fixup_nodes(); qcom_board_init(); return 0; }
diff --git a/arch/arm/mach-snapdragon/of_fixup.c b/arch/arm/mach-snapdragon/of_fixup.c new file mode 100644 index 000000000000..6810c8617cc0 --- /dev/null +++ b/arch/arm/mach-snapdragon/of_fixup.c @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * OF_LIVE devicetree fixup. + * + * This file implements runtime fixups for Qualcomm DT to improve + * compatibility with U-Boot. This includes adjusting the USB nodes + * to only use USB high-speed, as well as remapping volume buttons + * to behave as up/down for navigating U-Boot. + * + * We use OF_LIVE for this rather than early FDT fixup for a couple + * of reasons: it has a much nicer API, is most likely more efficient, + * and our changes are only applied to U-Boot. This allows us to use a + * DT designed for Linux, run U-Boot with a modified version, and then + * boot Linux with the original FDT. + * + * Copyright (c) 2024 Linaro Ltd. + * Author: Caleb Connolly caleb.connolly@linaro.org + */ + +#include <dt-bindings/input/linux-event-codes.h> +#include <dm/of_access.h> +#include <dm/of.h> +#include <fdt_support.h> +#include <linux/errno.h> + +/* U-Boot only supports USB high-speed mode on Qualcomm platforms with DWC3 + * USB controllers. Rather than requiring source level DT changes, we fix up + * DT here. This improves compatibility with upstream DT and simplifies the + * porting process for new devices. + */ +static int fixup_qcom_dwc3(struct device_node *glue_np) +{ + struct device_node *dwc3; + int ret, len, hsphy_idx = 1; + const __be32 *phandles; + const char *second_phy_name; + + debug("Fixing up %s\n", glue_np->name); + + /* Tell the glue driver to configure the wrapper for high-speed only operation */ + ret = of_write_prop(glue_np, "qcom,select-utmi-as-pipe-clk", 0, NULL); + if (ret) { + log_err("Failed to add property 'qcom,select-utmi-as-pipe-clk': %d\n", ret); + return ret; + } + + /* Find the DWC3 node itself */ + dwc3 = of_find_compatible_node(glue_np, NULL, "snps,dwc3"); + if (!dwc3) { + log_err("Failed to find dwc3 node\n"); + return -ENOENT; + } + + phandles = of_get_property(dwc3, "phys", &len); + len /= sizeof(*phandles); + if (len == 1) { + log_debug("Only one phy, not a superspeed controller\n"); + return 0; + } + + /* Figure out if the superspeed phy is present and if so then which phy is it? */ + ret = of_property_read_string_index(dwc3, "phy-names", 1, &second_phy_name); + if (ret == -ENODATA) { + log_debug("Only one phy, not a super-speed controller\n"); + return 0; + } else if (ret) { + log_err("Failed to read second phy name: %d\n", ret); + return ret; + } + + if (!strncmp("usb3-phy", second_phy_name, strlen("usb3-phy"))) { + log_debug("Second phy isn't superspeed (is '%s') assuming first phy is SS\n", + second_phy_name); + hsphy_idx = 0; + } + + /* Overwrite the "phys" property to only contain the high-speed phy */ + ret = of_write_prop(dwc3, "phys", sizeof(*phandles), phandles + hsphy_idx); + if (ret) { + log_err("Failed to overwrite 'phys' property: %d\n", ret); + return ret; + } + + /* Overwrite "phy-names" to only contain a single entry */ + ret = of_write_prop(dwc3, "phy-names", strlen("usb2-phy"), "usb2-phy"); + if (ret) { + log_err("Failed to overwrite 'phy-names' property: %d\n", ret); + return ret; + } + + ret = of_write_prop(dwc3, "maximum-speed", strlen("high-speed"), "high-speed"); + if (ret) { + log_err("Failed to set 'maximum-speed' property: %d\n", ret); + return ret; + } + + return 0; +} + +static void fixup_usb_nodes(void) +{ + struct device_node *glue_np = NULL; + int ret; + + while ((glue_np = of_find_compatible_node(glue_np, NULL, "qcom,dwc3"))) { + ret = fixup_qcom_dwc3(glue_np); + if (ret) + log_warning("Failed to fixup node %s: %d\n", glue_np->name, ret); + } +} + +void qcom_of_fixup_nodes(void) +{ + fixup_usb_nodes(); +} diff --git a/arch/arm/mach-snapdragon/qcom-priv.h b/arch/arm/mach-snapdragon/qcom-priv.h new file mode 100644 index 000000000000..d18fd1883b7f --- /dev/null +++ b/arch/arm/mach-snapdragon/qcom-priv.h @@ -0,0 +1,19 @@ + +#ifndef __QCOM_PRIV_H__ +#define __QCOM_PRIV_H__ + +#if CONFIG_IS_ENABLED(OF_LIVE) +/** + * qcom_of_fixup_nodes() - Fixup Qualcomm DT nodes + * + * Adjusts nodes in the live tree to improve compatibility with U-Boot. + */ +void qcom_of_fixup_nodes(void); +#else +static inline void qcom_of_fixup_nodes(void) +{ + log_debug("Unable to dynamically fixup USB nodes, please enable CONFIG_OF_LIVE\n"); +} +#endif /* OF_LIVE */ + +#endif /* __QCOM_PRIV_H__ */