diff options
Diffstat (limited to 'arch/arm/mach-snapdragon/of_fixup.c')
| -rw-r--r-- | arch/arm/mach-snapdragon/of_fixup.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/arch/arm/mach-snapdragon/of_fixup.c b/arch/arm/mach-snapdragon/of_fixup.c new file mode 100644 index 00000000000..3f7ac227bd0 --- /dev/null +++ b/arch/arm/mach-snapdragon/of_fixup.c @@ -0,0 +1,155 @@ +// 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> +#include <stdlib.h> +#include <time.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); + } +} + +/* Remove all references to the rpmhpd device */ +static void fixup_power_domains(void) +{ + struct device_node *pd = NULL, *np = NULL; + struct property *prop; + const __be32 *val; + + /* All Qualcomm platforms name the rpm(h)pd "power-controller" */ + for_each_of_allnodes(pd) { + if (pd->name && !strcmp("power-controller", pd->name)) + break; + } + + /* Sanity check that this is indeed a power domain controller */ + if (!of_find_property(pd, "#power-domain-cells", NULL)) { + log_err("Found power-controller but it doesn't have #power-domain-cells\n"); + return; + } + + /* Remove all references to the power domain controller */ + for_each_of_allnodes(np) { + if (!(prop = of_find_property(np, "power-domains", NULL))) + continue; + + val = prop->value; + if (val[0] == cpu_to_fdt32(pd->phandle)) + of_remove_property(np, prop); + } +} + +#define time_call(func, ...) \ + do { \ + u64 start = timer_get_us(); \ + func(__VA_ARGS__); \ + debug(#func " took %lluus\n", timer_get_us() - start); \ + } while (0) + +void qcom_of_fixup_nodes(void) +{ + time_call(fixup_usb_nodes); + time_call(fixup_power_domains); +} |