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