1/*- 2 * SPDX-License-Identifier: ISC 3 * 4 * Copyright (c) 2020 Dr Robert Harvey Crowston <crowston@protonmail.com> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 * 18 * 19 * $FreeBSD$ 20 * 21 */ 22 23/* 24 * VIA VL805 controller on the Raspberry Pi 4. 25 * The VL805 is a generic xhci controller. However, in the newer hardware 26 * revisions of the Raspberry Pi 4, it is incapable of loading its own firmware. 27 * Instead, the VideoCore GPU must load the firmware into the controller at the 28 * appropriate time. This driver is a shim that pre-loads the firmware before 29 * handing control to the xhci generic driver. 30 */ 31 32#include <sys/cdefs.h> 33__FBSDID("$FreeBSD$"); 34 35#include <sys/stdint.h> 36#include <sys/stddef.h> 37#include <sys/param.h> 38#include <sys/queue.h> 39#include <sys/types.h> 40#include <sys/systm.h> 41#include <sys/kernel.h> 42#include <sys/bus.h> 43#include <sys/module.h> 44#include <sys/lock.h> 45#include <sys/mutex.h> 46#include <sys/condvar.h> 47#include <sys/sysctl.h> 48#include <sys/sx.h> 49#include <sys/unistd.h> 50#include <sys/callout.h> 51#include <sys/malloc.h> 52#include <sys/priv.h> 53 54#include <dev/usb/usb.h> 55#include <dev/usb/usbdi.h> 56 57#include <dev/usb/usb_core.h> 58#include <dev/usb/usb_busdma.h> 59#include <dev/usb/usb_process.h> 60#include <dev/usb/usb_util.h> 61 62#include <dev/usb/usb_controller.h> 63#include <dev/usb/usb_bus.h> 64#include <dev/usb/usb_pci.h> 65#include <dev/usb/controller/xhci.h> 66 67#include <dev/ofw/openfirm.h> 68#include <dev/ofw/ofw_bus.h> 69#include <dev/ofw/ofw_bus_subr.h> 70 71#include <arm/broadcom/bcm2835/bcm2835_mbox_prop.h> 72 73#define VL805_FIRMWARE_REG 0x50 74#define PCIE_BUS_SHIFT 20 75#define PCIE_SLOT_SHIFT 15 76#define PCIE_FUNC_SHIFT 12 77 78static int 79bcm_xhci_probe(device_t dev) 80{ 81 phandle_t root; 82 uint32_t device_id; 83 84 device_id = pci_get_devid(dev); 85 if (device_id != 0x34831106) /* VIA VL805 USB 3.0 controller. */ 86 return (ENXIO); 87 88 /* 89 * The VIA chip is not unique to the Pi, but we only want to use this 90 * driver if the SoC is a Raspberry Pi 4. Walk the device tree to 91 * discover if the system is a Pi 4. 92 */ 93 root = OF_finddevice("/"); 94 if (root == -1) 95 return (ENXIO); 96 if (!ofw_bus_node_is_compatible(root, "raspberrypi,4-model-b")) 97 return (ENXIO); 98 99 /* 100 * On the Pi 4, the VIA chip with the firmware-loading limitation is 101 * soldered-on to a particular bus/slot/function. But, it's possible a 102 * user could desolder the VIA chip, replace it with a pci-pci bridge, 103 * then plug in a commodity VIA PCI-e card on the new bridge. In that 104 * case we don't want to try to load the firmware to a commodity 105 * expansion card. 106 */ 107 if (pci_get_bus(dev) != 1 || pci_get_slot(dev) != 0 || 108 pci_get_function(dev) != 0 ) 109 return (ENXIO); 110 111 device_set_desc(dev, 112 "VL805 USB 3.0 controller (on the Raspberry Pi 4b)"); 113 114 return (BUS_PROBE_SPECIFIC); 115} 116 117static uint32_t 118bcm_xhci_check_firmware(device_t dev, bool expect_loaded) 119{ 120 uint32_t revision; 121 bool loaded; 122 123 revision = pci_read_config(dev, VL805_FIRMWARE_REG, 4); 124 loaded = !(revision == 0 || revision == 0xffffffff); 125 126 if (expect_loaded && !loaded) 127 device_printf(dev, "warning: xhci firmware not found.\n"); 128 else if (bootverbose && !loaded) 129 device_printf(dev, "note: xhci firmware not found.\n"); 130 else if (bootverbose) 131 device_printf(dev, 132 "note: xhci firmware detected; firmware is revision %x.\n", 133 revision); 134 135 if (!loaded) 136 return 0; 137 138 return (revision); 139} 140 141static void 142bcm_xhci_install_xhci_firmware(device_t dev) 143{ 144 uint32_t revision, dev_addr; 145 int error; 146 147 revision = bcm_xhci_check_firmware(dev, false); 148 if (revision > 0) { 149 /* 150 * With the pre-June 2020 boot firmware, it does not seem 151 * possible to reload already-installed xhci firmware. 152 */ 153 return; 154 } 155 156 /* 157 * Notify the VideoCore gpu processor that it needs to reload the xhci 158 * firmware into the xhci controller. This needs to happen after the pci 159 * bridge topology is registered with the controller. 160 */ 161 if (bootverbose) 162 device_printf(dev, "note: installing xhci firmware.\n"); 163 164 dev_addr = 165 pci_get_bus(dev) << PCIE_BUS_SHIFT | 166 pci_get_slot(dev) << PCIE_SLOT_SHIFT | 167 pci_get_function(dev) << PCIE_FUNC_SHIFT; 168 169 error = bcm2835_mbox_notify_xhci_reset(dev_addr); 170 if (error) 171 device_printf(dev, 172 "warning: xhci firmware install failed (error %d).\n", 173 error); 174 175 DELAY(1000); 176 bcm_xhci_check_firmware(dev, true); 177 178 return; 179} 180 181static int 182bcm_xhci_attach(device_t dev) 183{ 184 struct xhci_softc *sc; 185 int error; 186 187 sc = device_get_softc(dev); 188 189 bcm_xhci_install_xhci_firmware(dev); 190 191 error = xhci_pci_attach(dev); 192 if (error) 193 return (error); 194 195 /* 32 bit DMA is a limitation of the PCI-e controller, not the VL805. */ 196 sc->sc_bus.dma_bits = 32; 197 if (bootverbose) 198 device_printf(dev, "note: switched to 32-bit DMA.\n"); 199 200 return (0); 201} 202 203/* 204 * Device method table. 205 */ 206static device_method_t bcm_xhci_methods[] = { 207 /* Device interface. */ 208 DEVMETHOD(device_probe, bcm_xhci_probe), 209 DEVMETHOD(device_attach, bcm_xhci_attach), 210}; 211 212DEFINE_CLASS_1(bcm_xhci, bcm_xhci_driver, bcm_xhci_methods, 213 sizeof(struct xhci_softc), xhci_pci_driver); 214 215static devclass_t xhci_devclass; 216DRIVER_MODULE(bcm_xhci, pci, bcm_xhci_driver, xhci_devclass, 0, 0); MODULE_DEPEND(bcm_xhci, usb, 1, 1, 1); 217