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 */ 20 21/* 22 * VIA VL805 controller on the Raspberry Pi 4. 23 * The VL805 is a generic xhci controller. However, in the newer hardware 24 * revisions of the Raspberry Pi 4, it is incapable of loading its own firmware. 25 * Instead, the VideoCore GPU must load the firmware into the controller at the 26 * appropriate time. This driver is a shim that pre-loads the firmware before 27 * handing control to the xhci generic driver. 28 */ 29 30#include <sys/cdefs.h> 31#include <sys/stdint.h> 32#include <sys/stddef.h> 33#include <sys/param.h> 34#include <sys/queue.h> 35#include <sys/types.h> 36#include <sys/systm.h> 37#include <sys/kernel.h> 38#include <sys/bus.h> 39#include <sys/module.h> 40#include <sys/lock.h> 41#include <sys/mutex.h> 42#include <sys/condvar.h> 43#include <sys/sysctl.h> 44#include <sys/sx.h> 45#include <sys/unistd.h> 46#include <sys/callout.h> 47#include <sys/malloc.h> 48#include <sys/priv.h> 49 50#include <dev/usb/usb.h> 51#include <dev/usb/usbdi.h> 52 53#include <dev/usb/usb_core.h> 54#include <dev/usb/usb_busdma.h> 55#include <dev/usb/usb_process.h> 56#include <dev/usb/usb_util.h> 57 58#include <dev/usb/usb_controller.h> 59#include <dev/usb/usb_bus.h> 60#include <dev/usb/usb_pci.h> 61#include <dev/usb/controller/xhci.h> 62 63#include <dev/ofw/openfirm.h> 64#include <dev/ofw/ofw_bus.h> 65#include <dev/ofw/ofw_bus_subr.h> 66 67#include <arm/broadcom/bcm2835/bcm2835_mbox_prop.h> 68 69#define VL805_FIRMWARE_REG 0x50 70#define PCIE_BUS_SHIFT 20 71#define PCIE_SLOT_SHIFT 15 72#define PCIE_FUNC_SHIFT 12 73 74static int 75bcm_xhci_probe(device_t dev) 76{ 77 phandle_t root; 78 uint32_t device_id; 79 80 device_id = pci_get_devid(dev); 81 if (device_id != 0x34831106) /* VIA VL805 USB 3.0 controller. */ 82 return (ENXIO); 83 84 /* 85 * The VIA chip is not unique to the Pi, but we only want to use this 86 * driver if the SoC is a Raspberry Pi 4. Walk the device tree to 87 * discover if the system is a Pi 4. 88 */ 89 root = OF_finddevice("/"); 90 if (root == -1) 91 return (ENXIO); 92 if (!ofw_bus_node_is_compatible(root, "raspberrypi,4-model-b")) 93 return (ENXIO); 94 95 /* 96 * On the Pi 4, the VIA chip with the firmware-loading limitation is 97 * soldered-on to a particular bus/slot/function. But, it's possible a 98 * user could desolder the VIA chip, replace it with a pci-pci bridge, 99 * then plug in a commodity VIA PCI-e card on the new bridge. In that 100 * case we don't want to try to load the firmware to a commodity 101 * expansion card. 102 */ 103 if (pci_get_bus(dev) != 1 || pci_get_slot(dev) != 0 || 104 pci_get_function(dev) != 0 ) 105 return (ENXIO); 106 107 device_set_desc(dev, 108 "VL805 USB 3.0 controller (on the Raspberry Pi 4b)"); 109 110 return (BUS_PROBE_SPECIFIC); 111} 112 113static uint32_t 114bcm_xhci_check_firmware(device_t dev, bool expect_loaded) 115{ 116 uint32_t revision; 117 bool loaded; 118 119 revision = pci_read_config(dev, VL805_FIRMWARE_REG, 4); 120 loaded = !(revision == 0 || revision == 0xffffffff); 121 122 if (expect_loaded && !loaded) 123 device_printf(dev, "warning: xhci firmware not found.\n"); 124 else if (bootverbose && !loaded) 125 device_printf(dev, "note: xhci firmware not found.\n"); 126 else if (bootverbose) 127 device_printf(dev, 128 "note: xhci firmware detected; firmware is revision %x.\n", 129 revision); 130 131 if (!loaded) 132 return 0; 133 134 return (revision); 135} 136 137static void 138bcm_xhci_install_xhci_firmware(device_t dev) 139{ 140 uint32_t revision, dev_addr; 141 int error; 142 143 revision = bcm_xhci_check_firmware(dev, false); 144 if (revision > 0) { 145 /* 146 * With the pre-June 2020 boot firmware, it does not seem 147 * possible to reload already-installed xhci firmware. 148 */ 149 return; 150 } 151 152 /* 153 * Notify the VideoCore gpu processor that it needs to reload the xhci 154 * firmware into the xhci controller. This needs to happen after the pci 155 * bridge topology is registered with the controller. 156 */ 157 if (bootverbose) 158 device_printf(dev, "note: installing xhci firmware.\n"); 159 160 dev_addr = 161 pci_get_bus(dev) << PCIE_BUS_SHIFT | 162 pci_get_slot(dev) << PCIE_SLOT_SHIFT | 163 pci_get_function(dev) << PCIE_FUNC_SHIFT; 164 165 error = bcm2835_mbox_notify_xhci_reset(dev_addr); 166 if (error) 167 device_printf(dev, 168 "warning: xhci firmware install failed (error %d).\n", 169 error); 170 171 DELAY(1000); 172 bcm_xhci_check_firmware(dev, true); 173 174 return; 175} 176 177static int 178bcm_xhci_attach(device_t dev) 179{ 180 struct xhci_softc *sc; 181 int error; 182 183 sc = device_get_softc(dev); 184 185 bcm_xhci_install_xhci_firmware(dev); 186 187 error = xhci_pci_attach(dev); 188 if (error) 189 return (error); 190 191 /* 32 bit DMA is a limitation of the PCI-e controller, not the VL805. */ 192 sc->sc_bus.dma_bits = 32; 193 if (bootverbose) 194 device_printf(dev, "note: switched to 32-bit DMA.\n"); 195 196 return (0); 197} 198 199/* 200 * Device method table. 201 */ 202static device_method_t bcm_xhci_methods[] = { 203 /* Device interface. */ 204 DEVMETHOD(device_probe, bcm_xhci_probe), 205 DEVMETHOD(device_attach, bcm_xhci_attach), 206 207 DEVMETHOD_END, 208}; 209 210DEFINE_CLASS_1(bcm_xhci, bcm_xhci_driver, bcm_xhci_methods, 211 sizeof(struct xhci_softc), xhci_pci_driver); 212 213DRIVER_MODULE(bcm_xhci, pci, bcm_xhci_driver, 0, 0); 214MODULE_DEPEND(bcm_xhci, usb, 1, 1, 1); 215MODULE_DEPEND(bcm_xhci, pci, 1, 1, 1); 216MODULE_DEPEND(bcm_xhci, xhci, 1, 1, 1); 217