From patchwork Thu Sep 6 19:52:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ajay Gupta X-Patchwork-Id: 10591005 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 77240112B for ; Thu, 6 Sep 2018 19:52:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5EC702AF37 for ; Thu, 6 Sep 2018 19:52:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 526862AF40; Thu, 6 Sep 2018 19:52:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 210A22AF38 for ; Thu, 6 Sep 2018 19:52:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729347AbeIGA3c (ORCPT ); Thu, 6 Sep 2018 20:29:32 -0400 Received: from hqemgate15.nvidia.com ([216.228.121.64]:19882 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728996AbeIGA3c (ORCPT ); Thu, 6 Sep 2018 20:29:32 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 06 Sep 2018 12:52:17 -0700 Received: from HQMAIL107.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 06 Sep 2018 12:52:28 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 06 Sep 2018 12:52:28 -0700 Received: from BGMAIL101.nvidia.com (10.25.59.10) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Thu, 6 Sep 2018 19:52:26 +0000 Received: from ajayg.nvidia.com (172.17.171.18) by bgmail101.nvidia.com (10.25.59.10) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Thu, 6 Sep 2018 19:52:22 +0000 From: Ajay Gupta To: , CC: , , Ajay Gupta Subject: [PATCH v8 1/2] i2c: buses: add i2c bus driver for NVIDIA GPU Date: Thu, 6 Sep 2018 12:52:12 -0700 Message-ID: <1536263533-16660-1-git-send-email-ajayg@nvidia.com> X-Mailer: git-send-email 2.7.4 X-NVConfidentiality: public MIME-Version: 1.0 X-Originating-IP: [172.17.171.18] X-ClientProxiedBy: BGMAIL103.nvidia.com (10.25.59.12) To bgmail101.nvidia.com (10.25.59.10) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Latest NVIDIA GPU card has USB Type-C interface. There is a Type-C controller which can be accessed over I2C. This driver adds I2C bus driver to communicate with Type-C controller. I2C client driver will be part of USB Type-C UCSI driver. Signed-off-by: Ajay Gupta Reviewed-by: Andy Shevchenko Reviewed-by: Heikki Krogerus --- Changes from v1 -> v2 None Changes from v2 -> v3 Fixed review comments from Andy and Thierry Rename i2c-gpu.c -> i2c-nvidia-gpu.c Changes from v3 -> v4 Fixed review comments from Andy Changes from v4 -> v5 Fixed review comments from Andy Changes from v5 -> v6 None Changes from v6 -> v7 -> v8 Fixed review comments from Peter - Add implicit STOP for last write message - Add i2c_adapter_quirks with max_read_len and I2C_AQ_COMB flags Documentation/i2c/busses/i2c-nvidia-gpu | 18 ++ MAINTAINERS | 7 + drivers/i2c/busses/Kconfig | 9 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-nvidia-gpu.c | 400 ++++++++++++++++++++++++++++++++ 5 files changed, 435 insertions(+) create mode 100644 Documentation/i2c/busses/i2c-nvidia-gpu create mode 100644 drivers/i2c/busses/i2c-nvidia-gpu.c diff --git a/Documentation/i2c/busses/i2c-nvidia-gpu b/Documentation/i2c/busses/i2c-nvidia-gpu new file mode 100644 index 0000000..31884d2 --- /dev/null +++ b/Documentation/i2c/busses/i2c-nvidia-gpu @@ -0,0 +1,18 @@ +Kernel driver i2c-nvidia-gpu + +Datasheet: not publicly available. + +Authors: + Ajay Gupta + +Description +----------- + +i2c-nvidia-gpu is a driver for I2C controller included in NVIDIA Turing +and later GPUs and it is used to communicate with Type-C controller on GPUs. + +If your 'lspci -v' listing shows something like the following, + +01:00.3 Serial bus controller [0c80]: NVIDIA Corporation Device 1ad9 (rev a1) + +then this driver should support the I2C controller of your GPU. diff --git a/MAINTAINERS b/MAINTAINERS index 9ad052a..2d1c5a1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6797,6 +6797,13 @@ L: linux-acpi@vger.kernel.org S: Maintained F: drivers/i2c/i2c-core-acpi.c +I2C CONTROLLER DRIVER FOR NVIDIA GPU +M: Ajay Gupta +L: linux-i2c@vger.kernel.org +S: Maintained +F: Documentation/i2c/busses/i2c-nvidia-gpu +F: drivers/i2c/busses/i2c-nvidia-gpu.c + I2C MUXES M: Peter Rosin L: linux-i2c@vger.kernel.org diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 451d4ae..eed827b 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -224,6 +224,15 @@ config I2C_NFORCE2_S4985 This driver can also be built as a module. If so, the module will be called i2c-nforce2-s4985. +config I2C_NVIDIA_GPU + tristate "NVIDIA GPU I2C controller" + depends on PCI + help + If you say yes to this option, support will be included for the + NVIDIA GPU I2C controller which is used to communicate with the GPU's + Type-C controller. This driver can also be built as a module called + i2c-nvidia-gpu. + config I2C_SIS5595 tristate "SiS 5595" depends on PCI diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 18b26af..d499813 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -140,5 +140,6 @@ obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o obj-$(CONFIG_I2C_XGENE_SLIMPRO) += i2c-xgene-slimpro.o obj-$(CONFIG_SCx200_ACB) += scx200_acb.o obj-$(CONFIG_I2C_FSI) += i2c-fsi.o +obj-$(CONFIG_I2C_NVIDIA_GPU) += i2c-nvidia-gpu.o ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG diff --git a/drivers/i2c/busses/i2c-nvidia-gpu.c b/drivers/i2c/busses/i2c-nvidia-gpu.c new file mode 100644 index 0000000..4816a31 --- /dev/null +++ b/drivers/i2c/busses/i2c-nvidia-gpu.c @@ -0,0 +1,400 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Nvidia GPU I2C controller Driver + * + * Copyright (C) 2018 NVIDIA Corporation. All rights reserved. + * Author: Ajay Gupta + */ +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/* I2C definitions */ +#define I2C_MST_CNTL 0x00 +#define I2C_MST_CNTL_GEN_START BIT(0) +#define I2C_MST_CNTL_GEN_STOP BIT(1) +#define I2C_MST_CNTL_CMD_NONE (0 << 2) +#define I2C_MST_CNTL_CMD_READ (1 << 2) +#define I2C_MST_CNTL_CMD_WRITE (2 << 2) +#define I2C_MST_CNTL_GEN_RAB BIT(4) +#define I2C_MST_CNTL_BURST_SIZE_SHIFT 6 +#define I2C_MST_CNTL_GEN_NACK BIT(28) +#define I2C_MST_CNTL_STATUS GENMASK(30, 29) +#define I2C_MST_CNTL_STATUS_OKAY (0 << 29) +#define I2C_MST_CNTL_STATUS_NO_ACK (1 << 29) +#define I2C_MST_CNTL_STATUS_TIMEOUT (2 << 29) +#define I2C_MST_CNTL_STATUS_BUS_BUSY (3 << 29) +#define I2C_MST_CNTL_CYCLE_TRIGGER BIT(31) + +#define I2C_MST_ADDR 0x04 +#define I2C_MST_ADDR_DAB 0 + +#define I2C_MST_I2C0_TIMING 0x08 +#define I2C_MST_I2C0_TIMING_SCL_PERIOD_100KHZ 0x10e +#define I2C_MST_I2C0_TIMING_TIMEOUT_CLK_CNT 16 +#define I2C_MST_I2C0_TIMING_TIMEOUT_CLK_CNT_MAX 255 +#define I2C_MST_I2C0_TIMING_TIMEOUT_CHECK BIT(24) + +#define I2C_MST_DATA 0x0c + +#define I2C_MST_HYBRID_PADCTL 0x20 +#define I2C_MST_HYBRID_PADCTL_MODE_I2C BIT(0) +#define I2C_MST_HYBRID_PADCTL_I2C_SCL_INPUT_RCV BIT(14) +#define I2C_MST_HYBRID_PADCTL_I2C_SDA_INPUT_RCV BIT(15) + +struct gpu_i2c_dev { + struct device *dev; + void __iomem *regs; + struct i2c_adapter adapter; + struct i2c_client *client; + struct mutex mutex; /* to sync read/write */ + bool do_start; +}; + +static void gpu_enable_i2c_bus(struct gpu_i2c_dev *i2cd) +{ + u32 val; + + /* enable I2C */ + val = readl(i2cd->regs + I2C_MST_HYBRID_PADCTL); + val |= I2C_MST_HYBRID_PADCTL_MODE_I2C | + I2C_MST_HYBRID_PADCTL_I2C_SCL_INPUT_RCV | + I2C_MST_HYBRID_PADCTL_I2C_SDA_INPUT_RCV; + writel(val, i2cd->regs + I2C_MST_HYBRID_PADCTL); + + /* enable 100KHZ mode */ + val = I2C_MST_I2C0_TIMING_SCL_PERIOD_100KHZ; + val |= (I2C_MST_I2C0_TIMING_TIMEOUT_CLK_CNT_MAX + << I2C_MST_I2C0_TIMING_TIMEOUT_CLK_CNT); + val |= I2C_MST_I2C0_TIMING_TIMEOUT_CHECK; + writel(val, i2cd->regs + I2C_MST_I2C0_TIMING); +} + +static int gpu_i2c_check_status(struct gpu_i2c_dev *i2cd) +{ + unsigned long target = jiffies + msecs_to_jiffies(1000); + u32 val; + + do { + val = readl(i2cd->regs + I2C_MST_CNTL); + if (!(val & I2C_MST_CNTL_CYCLE_TRIGGER)) + break; + if ((val & I2C_MST_CNTL_STATUS) != + I2C_MST_CNTL_STATUS_BUS_BUSY) + break; + usleep_range(1000, 2000); + } while (time_is_after_jiffies(target)); + if (time_is_before_jiffies(target)) { + dev_err(i2cd->dev, "i2c timeout error %x\n", val); + return -EIO; + } + + val = readl(i2cd->regs + I2C_MST_CNTL); + switch (val & I2C_MST_CNTL_STATUS) { + case I2C_MST_CNTL_STATUS_OKAY: + return 0; + case I2C_MST_CNTL_STATUS_NO_ACK: + return -EIO; + case I2C_MST_CNTL_STATUS_TIMEOUT: + return -ETIME; + case I2C_MST_CNTL_STATUS_BUS_BUSY: + return -EBUSY; + default: + return 0; + } +} + +static int gpu_i2c_read(struct gpu_i2c_dev *i2cd, u8 *data, u16 len) +{ + int status; + u32 val; + + val = I2C_MST_CNTL_GEN_START | I2C_MST_CNTL_GEN_STOP | + I2C_MST_CNTL_CMD_READ | (len << I2C_MST_CNTL_BURST_SIZE_SHIFT) | + I2C_MST_CNTL_CYCLE_TRIGGER | I2C_MST_CNTL_GEN_NACK; + val &= ~I2C_MST_CNTL_GEN_RAB; + writel(val, i2cd->regs + I2C_MST_CNTL); + + status = gpu_i2c_check_status(i2cd); + if (status < 0) + return status; + + val = readl(i2cd->regs + I2C_MST_DATA); + switch (len) { + case 1: + data[0] = val; + break; + case 2: + put_unaligned_be16(val, data); + break; + case 3: + put_unaligned_be16(val >> 8, data); + data[2] = val; + break; + case 4: + put_unaligned_be32(val, data); + break; + default: + break; + } + return status; +} + +static int gpu_i2c_start(struct gpu_i2c_dev *i2cd, u16 addr) +{ + u32 val; + + val = addr << I2C_MST_ADDR_DAB; + writel(val, i2cd->regs + I2C_MST_ADDR); + + val = I2C_MST_CNTL_GEN_START | I2C_MST_CNTL_CMD_NONE | + I2C_MST_CNTL_GEN_NACK; + val &= ~(I2C_MST_CNTL_GEN_STOP | I2C_MST_CNTL_GEN_RAB); + writel(val, i2cd->regs + I2C_MST_CNTL); + + return gpu_i2c_check_status(i2cd); +} + +static int gpu_i2c_stop(struct gpu_i2c_dev *i2cd) +{ + u32 val; + + val = I2C_MST_CNTL_GEN_STOP | I2C_MST_CNTL_CMD_NONE | + I2C_MST_CNTL_GEN_NACK; + val &= ~(I2C_MST_CNTL_GEN_START | I2C_MST_CNTL_GEN_RAB); + writel(val, i2cd->regs + I2C_MST_CNTL); + + return gpu_i2c_check_status(i2cd); +} + +static int gpu_i2c_write(struct gpu_i2c_dev *i2cd, u8 data) +{ + u32 val; + + writel(data, i2cd->regs + I2C_MST_DATA); + + val = I2C_MST_CNTL_CMD_WRITE | (1 << I2C_MST_CNTL_BURST_SIZE_SHIFT) | + I2C_MST_CNTL_GEN_NACK; + val &= ~(I2C_MST_CNTL_GEN_START | I2C_MST_CNTL_GEN_STOP | + I2C_MST_CNTL_GEN_RAB); + writel(val, i2cd->regs + I2C_MST_CNTL); + + return gpu_i2c_check_status(i2cd); +} + +static int gpu_i2c_master_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct gpu_i2c_dev *i2cd = i2c_get_adapdata(adap); + int status; + int i, j; + + mutex_lock(&i2cd->mutex); + for (i = 0; i < num; i++) { + if (msgs[i].flags & I2C_M_RD) { + /* gpu_i2c_read has implicit stop */ + status = gpu_i2c_read(i2cd, msgs[i].buf, msgs[i].len); + if (status < 0) + goto unlock; + i2cd->do_start = true; + } else { + if (i2cd->do_start) { + status = gpu_i2c_start(i2cd, msgs[i].addr); + if (status < 0) + goto unlock; + status = gpu_i2c_write(i2cd, msgs[i].addr << 1); + if (status < 0) + goto stop; + i2cd->do_start = false; + } + for (j = 0; j < msgs[i].len; j++) { + status = gpu_i2c_write(i2cd, msgs[i].buf[j]); + if (status < 0) + goto stop; + } + /* stop if last write message */ + if (i == (num - 1)) { + status = gpu_i2c_stop(i2cd); + if (status < 0) + goto unlock; + i2cd->do_start = true; + } + } + } + status = i; + goto unlock; +stop: + status = gpu_i2c_stop(i2cd); +unlock: + mutex_unlock(&i2cd->mutex); + return status; +} + +static const struct i2c_adapter_quirks gpu_i2c_quirks = { + .flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR, + .max_read_len = 4, +}; + +static u32 gpu_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm gpu_i2c_algorithm = { + .master_xfer = gpu_i2c_master_xfer, + .functionality = gpu_i2c_functionality, +}; + +/* + * This driver is for Nvidia GPU cards with USB Type-C interface. + * We want to identify the cards using vendor ID and class code only + * to avoid dependency of adding product id for any new card which + * requires this driver. + * Currently there is no class code defined for UCSI device over PCI + * so using UNKNOWN class for now and it will be updated when UCSI + * over PCI gets a class code. + * There is no other NVIDIA cards with UNKNOWN class code. Even if the + * driver gets loaded for an undesired card then eventually i2c_read() + * (initiated from UCSI i2c_client) will timeout or UCSI commands will + * timeout. + */ +#define PCI_CLASS_SERIAL_UNKNOWN 0x0c80 +static const struct pci_device_id gpu_i2c_ids[] = { + { PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, + PCI_CLASS_SERIAL_UNKNOWN << 8, 0xffffff00}, + { } +}; +MODULE_DEVICE_TABLE(pci, gpu_i2c_ids); + +static int gpu_populate_client(struct gpu_i2c_dev *i2cd, int irq) +{ + static struct i2c_board_info gpu_ccgx_ucsi = { + I2C_BOARD_INFO("ccgx-ucsi", 0x8), + }; + + gpu_ccgx_ucsi.irq = irq; + i2cd->client = i2c_new_device(&i2cd->adapter, &gpu_ccgx_ucsi); + if (!i2cd->client) { + dev_err(i2cd->dev, "i2c_new_device failed\n"); + return -ENODEV; + } + return 0; +} + +static int gpu_i2c_probe(struct pci_dev *pdev, const struct pci_device_id *id) +{ + struct gpu_i2c_dev *i2cd; + int status; + + i2cd = devm_kzalloc(&pdev->dev, sizeof(struct gpu_i2c_dev), GFP_KERNEL); + if (!i2cd) + return -ENOMEM; + + i2cd->dev = &pdev->dev; + dev_set_drvdata(&pdev->dev, i2cd); + + status = pcim_enable_device(pdev); + if (status < 0) { + dev_err(&pdev->dev, "pcim_enable_device failed %d\n", status); + return status; + } + + pci_set_master(pdev); + + i2cd->regs = pcim_iomap(pdev, 0, 0); + if (!i2cd->regs) { + dev_err(&pdev->dev, "pcim_iomap failed\n"); + return -ENOMEM; + } + + status = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI); + if (status < 0) { + dev_err(&pdev->dev, "pci_alloc_irq_vectors err %d\n", status); + return status; + } + + i2cd->do_start = true; + mutex_init(&i2cd->mutex); + gpu_enable_i2c_bus(i2cd); + + i2c_set_adapdata(&i2cd->adapter, i2cd); + i2cd->adapter.owner = THIS_MODULE; + strlcpy(i2cd->adapter.name, "NVIDIA GPU I2C adapter", + sizeof(i2cd->adapter.name)); + i2cd->adapter.algo = &gpu_i2c_algorithm; + i2cd->adapter.quirks = &gpu_i2c_quirks; + i2cd->adapter.dev.parent = &pdev->dev; + status = i2c_add_adapter(&i2cd->adapter); + if (status < 0) { + dev_err(&pdev->dev, "i2c_add_adapter failed %d\n", status); + goto free_irq_vectors; + } + + status = gpu_populate_client(i2cd, pdev->irq); + if (status < 0) { + dev_err(&pdev->dev, "gpu_populate_client failed %d\n", status); + goto del_adapter; + } + + return 0; + +del_adapter: + i2c_del_adapter(&i2cd->adapter); +free_irq_vectors: + pci_free_irq_vectors(pdev); + return status; +} + +static void gpu_i2c_remove(struct pci_dev *pdev) +{ + struct gpu_i2c_dev *i2cd = dev_get_drvdata(&pdev->dev); + + i2c_del_adapter(&i2cd->adapter); + pci_free_irq_vectors(pdev); +} + +static int gpu_i2c_resume(struct device *dev) +{ + struct gpu_i2c_dev *i2cd = dev_get_drvdata(dev); + + gpu_enable_i2c_bus(i2cd); + return 0; +} + +static int gpu_i2c_idle(struct device *dev) +{ + struct gpu_i2c_dev *i2cd = dev_get_drvdata(dev); + + if (!mutex_trylock(&i2cd->mutex)) { + dev_info(dev, "-EBUSY\n"); + return -EBUSY; + } + mutex_unlock(&i2cd->mutex); + + return 0; +} + +UNIVERSAL_DEV_PM_OPS(gpu_i2c_driver_pm, NULL, gpu_i2c_resume, gpu_i2c_idle); + +static struct pci_driver gpu_i2c_driver = { + .name = "nvidia-gpu", + .id_table = gpu_i2c_ids, + .probe = gpu_i2c_probe, + .remove = gpu_i2c_remove, + .driver = { + .pm = &gpu_i2c_driver_pm, + }, +}; + +module_pci_driver(gpu_i2c_driver); + +MODULE_AUTHOR("Ajay Gupta "); +MODULE_DESCRIPTION("Nvidia GPU I2C controller Driver"); +MODULE_LICENSE("GPL v2"); From patchwork Thu Sep 6 19:52:13 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ajay Gupta X-Patchwork-Id: 10591007 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 36BC6112B for ; Thu, 6 Sep 2018 19:52:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1E5D62AF37 for ; Thu, 6 Sep 2018 19:52:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 120FD2AF40; Thu, 6 Sep 2018 19:52:36 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 451A22AF37 for ; 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Thu, 6 Sep 2018 19:52:26 +0000 From: Ajay Gupta To: , CC: , , Ajay Gupta Subject: [PATCH v8 2/2] usb: typec: ucsi: add support for Cypress CCGx Date: Thu, 6 Sep 2018 12:52:13 -0700 Message-ID: <1536263533-16660-2-git-send-email-ajayg@nvidia.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1536263533-16660-1-git-send-email-ajayg@nvidia.com> References: <1536263533-16660-1-git-send-email-ajayg@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 X-Originating-IP: [172.17.171.18] X-ClientProxiedBy: BGMAIL103.nvidia.com (10.25.59.12) To bgmail101.nvidia.com (10.25.59.10) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Latest NVIDIA GPU cards have a Cypress CCGx Type-C controller over I2C interface. This UCSI I2C driver uses I2C bus driver interface for communicating with Type-C controller. Signed-off-by: Ajay Gupta --- Changes from v1 -> v2 Fixed identation in drivers/usb/typec/ucsi/Kconfig Changes from v2 -> v3 Fixed most of comments from Heikki Rename ucsi_i2c_ccg.c -> ucsi_ccg.c Changes from v3 -> v4 Fixed comments from Andy Changes from v4 -> v5 Fixed comments from Andy Changes from v5 -> v6 Fixed review comments from Greg Changes from v6 -> v7 None Changes from v7 -> v8 Fixed review comments from Peter - Removed empty STOP message - Using stack memory for i2c_transfer() drivers/usb/typec/ucsi/Kconfig | 10 ++ drivers/usb/typec/ucsi/Makefile | 2 + drivers/usb/typec/ucsi/ucsi_ccg.c | 335 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 347 insertions(+) create mode 100644 drivers/usb/typec/ucsi/ucsi_ccg.c diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig index e36d6c7..7811888 100644 --- a/drivers/usb/typec/ucsi/Kconfig +++ b/drivers/usb/typec/ucsi/Kconfig @@ -23,6 +23,16 @@ config TYPEC_UCSI if TYPEC_UCSI +config UCSI_CCG + tristate "UCSI Interface Driver for Cypress CCGx" + depends on I2C + help + This driver enables UCSI support on platforms that expose a + Cypress CCGx Type-C controller over I2C interface. + + To compile the driver as a module, choose M here: the module will be + called ucsi_ccg. + config UCSI_ACPI tristate "UCSI ACPI Interface Driver" depends on ACPI diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile index 7afbea5..2f4900b 100644 --- a/drivers/usb/typec/ucsi/Makefile +++ b/drivers/usb/typec/ucsi/Makefile @@ -8,3 +8,5 @@ typec_ucsi-y := ucsi.o typec_ucsi-$(CONFIG_TRACING) += trace.o obj-$(CONFIG_UCSI_ACPI) += ucsi_acpi.o + +obj-$(CONFIG_UCSI_CCG) += ucsi_ccg.o diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c new file mode 100644 index 0000000..387b6fd --- /dev/null +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c @@ -0,0 +1,335 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * UCSI driver for Cypress CCGx Type-C controller + * + * Copyright (C) 2017-2018 NVIDIA Corporation. All rights reserved. + * Author: Ajay Gupta + * + * Some code borrowed from drivers/usb/typec/ucsi/ucsi_acpi.c + */ +#include +#include +#include +#include +#include +#include + +#include +#include "ucsi.h" + +struct ucsi_ccg { + struct device *dev; + struct ucsi *ucsi; + struct ucsi_ppm ppm; + struct i2c_client *client; + int irq; +}; + +#define CCGX_I2C_RAB_DEVICE_MODE 0x00 +#define CCGX_I2C_RAB_READ_SILICON_ID 0x2 +#define CCGX_I2C_RAB_INTR_REG 0x06 +#define CCGX_I2C_RAB_FW1_VERSION 0x28 +#define CCGX_I2C_RAB_FW2_VERSION 0x20 +#define CCGX_I2C_RAB_UCSI_CONTROL 0x39 +#define CCGX_I2C_RAB_UCSI_CONTROL_START BIT(0) +#define CCGX_I2C_RAB_UCSI_CONTROL_STOP BIT(1) +#define CCGX_I2C_RAB_RESPONSE_REG 0x7E +#define CCGX_I2C_RAB_UCSI_DATA_BLOCK 0xf000 + +static int ccg_read(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len) +{ + struct i2c_client *client = uc->client; + unsigned char buf[2]; + struct i2c_msg msgs[] = { + { + .addr = client->addr, + .flags = 0x0, + .len = 0x2, + .buf = buf, + }, + { + .addr = client->addr, + .flags = I2C_M_RD, + .buf = data, + }, + }; + u32 rlen, rem_len = len; + int status; + + while (rem_len > 0) { + msgs[1].buf = &data[len - rem_len]; + rlen = min_t(u16, rem_len, 4); + msgs[1].len = rlen; + put_unaligned_le16(rab, buf); + status = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (status < 0) { + dev_err(uc->dev, "i2c_transfer failed %d\n", status); + return status; + } + rab += rlen; + rem_len -= rlen; + } + + return 0; +} + +static int ccg_write(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len) +{ + struct i2c_client *client = uc->client; + unsigned char buf[2]; + struct i2c_msg msgs[] = { + { + .addr = client->addr, + .flags = 0x0, + .len = 0x2, + .buf = buf, + }, + { + .addr = client->addr, + .flags = 0x0, + .buf = data, + .len = len, + }, + }; + int status; + + put_unaligned_le16(rab, buf); + status = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (status < 0) { + dev_err(uc->dev, "i2c_transfer failed %d\n", status); + return status; + } + + return 0; +} + +static int ucsi_ccg_init(struct ucsi_ccg *uc) +{ + struct device *dev = uc->dev; + unsigned int count = 10; + u8 data[64]; + int status; + + /* + * Selectively issue device reset + * - if RESPONSE register is RESET_COMPLETE, do not issue device reset + * (will cause usb device disconnect / reconnect) + * - if RESPONSE register is not RESET_COMPLETE, issue device reset + * (causes PPC to resync device connect state by re-issuing + * set mux command) + */ + data[0] = 0x00; + data[1] = 0x00; + + status = ccg_read(uc, CCGX_I2C_RAB_RESPONSE_REG, data, 0x2); + if (status < 0) + return status; + + memset(data, 0, sizeof(data)); + status = ccg_read(uc, CCGX_I2C_RAB_DEVICE_MODE, data, sizeof(data)); + if (status < 0) + return status; + + dev_dbg(dev, "Silicon id %2ph", data + CCGX_I2C_RAB_READ_SILICON_ID); + dev_dbg(dev, "FW1 version %8ph\n", data + CCGX_I2C_RAB_FW1_VERSION); + dev_dbg(dev, "FW2 version %8ph\n", data + CCGX_I2C_RAB_FW2_VERSION); + + data[0] = 0x0; + data[1] = 0x0; + status = ccg_read(uc, CCGX_I2C_RAB_RESPONSE_REG, data, 0x2); + if (status < 0) + return status; + + data[0] = CCGX_I2C_RAB_UCSI_CONTROL_STOP; + status = ccg_write(uc, CCGX_I2C_RAB_UCSI_CONTROL, data, 0x1); + if (status < 0) + return status; + + data[0] = CCGX_I2C_RAB_UCSI_CONTROL_START; + status = ccg_write(uc, CCGX_I2C_RAB_UCSI_CONTROL, data, 0x1); + if (status < 0) + return status; + + /* + * Flush CCGx RESPONSE queue by acking interrupts + * - above ucsi control register write will push response + * which must be flushed + * - affects f/w update which reads response register + */ + data[0] = 0xff; + do { + status = ccg_write(uc, CCGX_I2C_RAB_INTR_REG, data, 0x1); + if (status < 0) + return status; + + usleep_range(10000, 11000); + + status = ccg_read(uc, CCGX_I2C_RAB_INTR_REG, data, 0x1); + if (status < 0) + return status; + } while ((data[0] != 0x00) && count--); + + return 0; +} + +static int ucsi_ccg_send_data(struct ucsi_ccg *uc) +{ + int status; + unsigned char buf[4] = { + 0x20, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8, + 0x8, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8, + }; + unsigned char buf1[16]; + unsigned char buf2[8]; + + memcpy(buf1, ((const void *)uc->ppm.data) + 0x20, sizeof(buf1)); + memcpy(buf2, ((const void *)uc->ppm.data) + 0x8, sizeof(buf2)); + + status = ccg_write(uc, *(u16 *)buf, buf1, sizeof(buf1)); + if (status < 0) + return status; + + return ccg_write(uc, *(u16 *)(buf + 2), buf2, sizeof(buf2)); +} + +static int ucsi_ccg_recv_data(struct ucsi_ccg *uc) +{ + u8 *ppm = (u8 *)uc->ppm.data; + int status; + unsigned char buf[6] = { + 0x0, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8, + 0x4, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8, + 0x10, CCGX_I2C_RAB_UCSI_DATA_BLOCK >> 8, + }; + + status = ccg_read(uc, *(u16 *)buf, ppm, 0x2); + if (status < 0) + return status; + + status = ccg_read(uc, *(u16 *)(buf + 2), ppm + 0x4, 0x4); + if (status < 0) + return status; + + return ccg_read(uc, *(u16 *)(buf + 4), ppm + 0x10, 0x10); +} + +static int ucsi_ccg_ack_interrupt(struct ucsi_ccg *uc) +{ + int status; + unsigned char buf[2] = { + CCGX_I2C_RAB_INTR_REG, CCGX_I2C_RAB_INTR_REG >> 8}; + unsigned char buf2[1] = {0x0}; + + status = ccg_read(uc, *(u16 *)buf, buf2, 0x1); + if (status < 0) + return status; + + return ccg_write(uc, *(u16 *)buf, buf2, 0x1); +} + +static int ucsi_ccg_sync(struct ucsi_ppm *ppm) +{ + struct ucsi_ccg *uc = container_of(ppm, struct ucsi_ccg, ppm); + int status; + + status = ucsi_ccg_recv_data(uc); + if (status < 0) + return status; + + /* ack interrupt to allow next command to run */ + return ucsi_ccg_ack_interrupt(uc); +} + +static int ucsi_ccg_cmd(struct ucsi_ppm *ppm, struct ucsi_control *ctrl) +{ + struct ucsi_ccg *uc = container_of(ppm, struct ucsi_ccg, ppm); + + ppm->data->ctrl.raw_cmd = ctrl->raw_cmd; + return ucsi_ccg_send_data(uc); +} + +static irqreturn_t ccg_irq_handler(int irq, void *data) +{ + struct ucsi_ccg *uc = data; + + ucsi_notify(uc->ucsi); + + return IRQ_HANDLED; +} + +static int ucsi_ccg_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + struct ucsi_ccg *uc; + int status; + + uc = devm_kzalloc(dev, sizeof(*uc), GFP_KERNEL); + if (!uc) + return -ENOMEM; + + uc->ppm.data = devm_kzalloc(dev, sizeof(struct ucsi_data), GFP_KERNEL); + if (!uc->ppm.data) + return -ENOMEM; + + uc->ppm.cmd = ucsi_ccg_cmd; + uc->ppm.sync = ucsi_ccg_sync; + uc->dev = dev; + uc->client = client; + + /* reset ccg device and initialize ucsi */ + status = ucsi_ccg_init(uc); + if (status < 0) { + dev_err(uc->dev, "ucsi_ccg_init failed - %d\n", status); + return status; + } + + uc->irq = client->irq; + + status = devm_request_threaded_irq(dev, uc->irq, NULL, ccg_irq_handler, + IRQF_ONESHOT | IRQF_TRIGGER_HIGH, + dev_name(dev), uc); + if (status < 0) { + dev_err(uc->dev, "request_threaded_irq failed - %d\n", status); + return status; + } + + uc->ucsi = ucsi_register_ppm(dev, &uc->ppm); + if (IS_ERR(uc->ucsi)) { + dev_err(uc->dev, "ucsi_register_ppm failed\n"); + return PTR_ERR(uc->ucsi); + } + + i2c_set_clientdata(client, uc); + return 0; +} + +static int ucsi_ccg_remove(struct i2c_client *client) +{ + struct ucsi_ccg *uc = i2c_get_clientdata(client); + + ucsi_unregister_ppm(uc->ucsi); + + return 0; +} + +static const struct i2c_device_id ucsi_ccg_device_id[] = { + {"ccgx-ucsi", 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, ucsi_ccg_device_id); + +static struct i2c_driver ucsi_ccg_driver = { + .driver = { + .name = "ucsi_ccg", + }, + .probe = ucsi_ccg_probe, + .remove = ucsi_ccg_remove, + .id_table = ucsi_ccg_device_id, +}; + +module_i2c_driver(ucsi_ccg_driver); + +MODULE_AUTHOR("Ajay Gupta "); +MODULE_DESCRIPTION("UCSI driver for Cypress CCGx Type-C controller"); +MODULE_LICENSE("GPL v2");