From patchwork Mon Jun 8 19:26:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Saenz Julienne X-Patchwork-Id: 11593875 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 157C9739 for ; Mon, 8 Jun 2020 19:27:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0559B20760 for ; Mon, 8 Jun 2020 19:27:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726603AbgFHT1h (ORCPT ); Mon, 8 Jun 2020 15:27:37 -0400 Received: from mx2.suse.de ([195.135.220.15]:39610 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726428AbgFHT1f (ORCPT ); Mon, 8 Jun 2020 15:27:35 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 37619AE35; Mon, 8 Jun 2020 19:27:36 +0000 (UTC) From: Nicolas Saenz Julienne To: f.fainelli@gmail.com, gregkh@linuxfoundation.org, wahrenst@gmx.net, robh@kernel.org, mathias.nyman@linux.intel.com, Eric Anholt , bcm-kernel-feedback-list@broadcom.com, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-pci@vger.kernel.org, linux-usb@vger.kernel.org, Philipp Zabel Cc: linux-kernel@vger.kernel.org, tim.gover@raspberrypi.org, helgaas@kernel.org, lorenzo.pieralisi@arm.com, Nicolas Saenz Julienne Subject: [PATCH 2/9] reset: Add Raspberry Pi 4 firmware USB reset controller Date: Mon, 8 Jun 2020 21:26:54 +0200 Message-Id: <20200608192701.18355-3-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200608192701.18355-1-nsaenzjulienne@suse.de> References: <20200608192701.18355-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org The Raspberry Pi 4 gets its USB functionality from VL805, a PCIe chip that implements the xHCI. After a PCI fundamental reset, VL805's firmware may either be loaded directly from an EEPROM or, if not present, by the SoC's co-processor, VideoCore. RPi4's VideoCore OS contains both the non public firmware load logic and the VL805 firmware blob. We control this trough a reset controller device that's able to trigger the aforementioned process when relevant. Signed-off-by: Nicolas Saenz Julienne --- drivers/reset/Kconfig | 9 ++ drivers/reset/Makefile | 1 + drivers/reset/reset-raspberrypi-usb.c | 122 ++++++++++++++++++++++++++ 3 files changed, 132 insertions(+) create mode 100644 drivers/reset/reset-raspberrypi-usb.c diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index d9efbfd29646..80e07190cd04 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -140,6 +140,15 @@ config RESET_QCOM_PDC to control reset signals provided by PDC for Modem, Compute, Display, GPU, Debug, AOP, Sensors, Audio, SP and APPS. +config RESET_RASPBERRYPI_USB + tristate "Raspberry Pi 4 USB Reset Driver" + depends on RASPBERRYPI_FIRMWARE || (RASPBERRYPI_FIRMWARE=n && COMPILE_TEST) + default USB_XHCI_PCI + help + This driver provides support for resetting the USB HW available in + the Raspberry Pi 4. This reset process is controlled by firmware + through a custom interface (see drivers/firmware/raspberrypi.c). + config RESET_SCMI tristate "Reset driver controlled via ARM SCMI interface" depends on ARM_SCMI_PROTOCOL || COMPILE_TEST diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 249ed357c997..49cd2868c7ab 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o obj-$(CONFIG_RESET_QCOM_AOSS) += reset-qcom-aoss.o obj-$(CONFIG_RESET_QCOM_PDC) += reset-qcom-pdc.o +obj-$(CONFIG_RESET_RASPBERRYPI_USB) += reset-raspberrypi-usb.o obj-$(CONFIG_RESET_SCMI) += reset-scmi.o obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o obj-$(CONFIG_RESET_STM32MP157) += reset-stm32mp1.o diff --git a/drivers/reset/reset-raspberrypi-usb.c b/drivers/reset/reset-raspberrypi-usb.c new file mode 100644 index 000000000000..e9a6e7018c6d --- /dev/null +++ b/drivers/reset/reset-raspberrypi-usb.c @@ -0,0 +1,122 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Raspberry Pi 4 USB reset driver + * + * The Raspberry Pi 4 gets its USB functionality from VL805, a PCIe chip that + * implements xHCI. After a PCI reset, VL805's firmware may either be loaded + * directly from an EEPROM or, if not present, by the SoC's co-processor, + * VideoCore. rpi's VideoCore OS contains both the non public firmware load + * logic and the VL805 firmware blob. This driver triggers the aforementioned + * process. + * + * Copyright (C) 2020 Nicolas Saenz Julienne + */ +#include +#include +#include +#include +#include +#include +#include + +struct rpi_usb_reset { + struct reset_controller_dev rcdev; + struct rpi_firmware *fw; +}; + +static inline +struct rpi_usb_reset *to_rpi_usb(struct reset_controller_dev *rcdev) +{ + return container_of(rcdev, struct rpi_usb_reset, rcdev); +} + +static int rpi_usb_reset_reset(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct rpi_usb_reset *priv = to_rpi_usb(rcdev); + u32 dev_addr; + int ret; + + /* + * The pci device address is expected like this: + * + * PCI_BUS << 20 | PCI_SLOT << 15 | PCI_FUNC << 12 + * + * But since rpi's PCIe setup is hardwired, we know the address in + * advance. + */ + dev_addr = 0x100000; + ret = rpi_firmware_property(priv->fw, RPI_FIRMWARE_NOTIFY_XHCI_RESET, + &dev_addr, sizeof(dev_addr)); + if (ret) + return ret; + + /* Wait for vl805 to startup */ + usleep_range(200, 1000); + + return 0; +} + +static const struct reset_control_ops rpi_usb_reset_ops = { + .reset = rpi_usb_reset_reset, +}; + +static int rpi_usb_reset_xlate(struct reset_controller_dev *rcdev, + const struct of_phandle_args *reset_spec) +{ + /* This is needed if #reset-cells == 0. */ + return 0; +} + +static int rpi_usb_reset_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *fw_node; + struct rpi_usb_reset *priv; + struct rpi_firmware *fw; + + fw_node = of_get_parent(dev->of_node); + if (!fw_node) { + dev_err(dev, "Missing firmware node\n"); + return -ENOENT; + } + + fw = rpi_firmware_get(fw_node); + of_node_put(fw_node); + if (!fw) + return -EPROBE_DEFER; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + dev_set_drvdata(dev, priv); + + priv->fw = fw; + priv->rcdev.owner = THIS_MODULE; + priv->rcdev.nr_resets = 1; + priv->rcdev.ops = &rpi_usb_reset_ops; + priv->rcdev.of_node = dev->of_node; + priv->rcdev.of_xlate = rpi_usb_reset_xlate; + + return devm_reset_controller_register(dev, &priv->rcdev); +} + +static const struct of_device_id rpi_usb_reset_of_match[] = { + { .compatible = "raspberrypi,firmware-usb-reset" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, rpi_usb_reset_of_match); + +static struct platform_driver rpi_usb_reset_driver = { + .probe = rpi_usb_reset_probe, + .driver = { + .name = "raspberrypi-usb-reset", + .of_match_table = rpi_usb_reset_of_match, + }, +}; +module_platform_driver(rpi_usb_reset_driver); + +MODULE_AUTHOR("Nicolas Saenz Julienne "); +MODULE_DESCRIPTION("Raspberry Pi 4 USB reset driver"); +MODULE_LICENSE("GPL");