From patchwork Thu Jan 11 19:44:26 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baruch Siach X-Patchwork-Id: 859276 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3zHbvy3mYHz9sQm for ; Fri, 12 Jan 2018 06:45:50 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934356AbeAKTpp (ORCPT ); Thu, 11 Jan 2018 14:45:45 -0500 Received: from guitar.tcltek.co.il ([192.115.133.116]:59969 "EHLO mx.tkos.co.il" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934416AbeAKTpk (ORCPT ); Thu, 11 Jan 2018 14:45:40 -0500 Received: from tarshish.tkos.co.il (unknown [10.0.8.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx.tkos.co.il (Postfix) with ESMTPSA id 9B4B84404F8; Thu, 11 Jan 2018 21:45:19 +0200 (IST) From: Baruch Siach To: Dave Stevenson , Eric Anholt , Stefan Wahren , Linus Walleij Cc: linux-gpio@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, Michael Zoran , Baruch Siach Subject: [PATCH v2 3/4] gpio: raspberrypi-exp: Driver for RPi3 GPIO expander via mailbox service Date: Thu, 11 Jan 2018 21:44:26 +0200 Message-Id: <35b07d1aae959c357d671f5530311320d0f10cc8.1515698418.git.baruch@tkos.co.il> X-Mailer: git-send-email 2.15.1 In-Reply-To: References: Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org From: Dave Stevenson Pi3 and Compute Module 3 have a GPIO expander that the VPU communicates with. There is a mailbox service that now allows control of this expander, so add a kernel driver that can make use of it. Signed-off-by: Dave Stevenson Signed-off-by: Baruch Siach --- v2: * Rename driver to gpio-raspberrypi-exp * Populate the gpiochip parent device pointer * Use macro for the mailbox base GPIO number * Drop linux/gpio.h and GPIOF_DIR_* * Check and print firmware error value * Use devm_gpiochip_add_data(); drop .remove * A few more minor tweaks --- drivers/gpio/Kconfig | 9 ++ drivers/gpio/Makefile | 1 + drivers/gpio/gpio-raspberrypi-exp.c | 258 ++++++++++++++++++++++++++++++++++++ 3 files changed, 268 insertions(+) create mode 100644 drivers/gpio/gpio-raspberrypi-exp.c diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index d6a8e851ad13..8df901c75bef 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -128,6 +128,15 @@ config GPIO_AXP209 help Say yes to enable GPIO support for the AXP209 PMIC +config GPIO_RASPBERRYPI_EXP + bool "RaspberryPi 3 Exp GPIO" + default RASPBERRYPI_FIRMWARE + depends on OF_GPIO && RASPBERRYPI_FIRMWARE && \ + (ARCH_BCM2835 || COMPILE_TEST) + help + Turn on GPIO support for the expander on Raspberry Pi 3 boards, using + the firmware mailbox to communicate with VideoCore on BCM283x chips. + config GPIO_BCM_KONA bool "Broadcom Kona GPIO" depends on OF_GPIO && (ARCH_BCM_MOBILE || COMPILE_TEST) diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 4bc24febb889..71021b0e71da 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -33,6 +33,7 @@ obj-$(CONFIG_GPIO_ARIZONA) += gpio-arizona.o obj-$(CONFIG_GPIO_ATH79) += gpio-ath79.o obj-$(CONFIG_GPIO_ASPEED) += gpio-aspeed.o obj-$(CONFIG_GPIO_AXP209) += gpio-axp209.o +obj-$(CONFIG_GPIO_RASPBERRYPI_EXP) += gpio-raspberrypi-exp.o obj-$(CONFIG_GPIO_BCM_KONA) += gpio-bcm-kona.o obj-$(CONFIG_GPIO_BD9571MWV) += gpio-bd9571mwv.o obj-$(CONFIG_GPIO_BRCMSTB) += gpio-brcmstb.o diff --git a/drivers/gpio/gpio-raspberrypi-exp.c b/drivers/gpio/gpio-raspberrypi-exp.c new file mode 100644 index 000000000000..95b1957a69fa --- /dev/null +++ b/drivers/gpio/gpio-raspberrypi-exp.c @@ -0,0 +1,258 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Raspberry Pi 3 expander GPIO driver + * + * Uses the firmware mailbox service to communicate with the + * GPIO expander on the VPU. + * + * Copyright (C) 2017 Raspberry Pi Trading Ltd. + */ + +#include +#include +#include +#include +#include +#include + +#define MODULE_NAME "raspberrypi-exp-gpio" +#define NUM_GPIO 8 + +#define RPI_EXP_GPIO_BASE 128 + +#define RPI_EXP_GPIO_DIR_IN 0 +#define RPI_EXP_GPIO_DIR_OUT 1 + +struct rpi_exp_gpio { + struct gpio_chip gc; + struct rpi_firmware *fw; +}; + +/* VC4 firmware mailbox interface data structures */ + +struct gpio_set_config { + u32 gpio; + u32 direction; + u32 polarity; + u32 term_en; + u32 term_pull_up; + u32 state; +}; + +struct gpio_get_config { + u32 gpio; + u32 direction; + u32 polarity; + u32 term_en; + u32 term_pull_up; +}; + +struct gpio_get_set_state { + u32 gpio; + u32 state; +}; + +static int rpi_exp_gpio_get_polarity(struct gpio_chip *gc, unsigned int off) +{ + struct rpi_exp_gpio *gpio; + struct gpio_get_config get; + int ret; + + gpio = gpiochip_get_data(gc); + + get.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */ + + ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG, + &get, sizeof(get)); + if (ret || get.gpio != 0) { + dev_err(gc->parent, + "Failed to get GPIO %u config (%d %x)\n", off, ret, + get.gpio); + return ret ? ret : -EIO; + } + return get.polarity; +} + +static int rpi_exp_gpio_dir_in(struct gpio_chip *gc, unsigned int off) +{ + struct rpi_exp_gpio *gpio; + struct gpio_set_config set_in; + int ret; + + gpio = gpiochip_get_data(gc); + + set_in.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */ + set_in.direction = RPI_EXP_GPIO_DIR_IN; + set_in.polarity = rpi_exp_gpio_get_polarity(gc, off); + /* Retain existing setting */ + set_in.term_en = 0; /* termination disabled */ + set_in.term_pull_up = 0; /* n/a as termination disabled */ + set_in.state = 0; /* n/a as configured as an input */ + + ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG, + &set_in, sizeof(set_in)); + if (ret || set_in.gpio != 0) { + dev_err(gc->parent, + "Failed to set GPIO %u to input (%d %x)\n", + off, ret, set_in.gpio); + return ret ? ret : -EIO; + } + return 0; +} + +static int rpi_exp_gpio_dir_out(struct gpio_chip *gc, unsigned int off, int val) +{ + struct rpi_exp_gpio *gpio; + struct gpio_set_config set_out; + int ret; + + gpio = gpiochip_get_data(gc); + + set_out.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */ + set_out.direction = RPI_EXP_GPIO_DIR_OUT; + set_out.polarity = rpi_exp_gpio_get_polarity(gc, off); + /* Retain existing setting */ + set_out.term_en = 0; /* n/a as an output */ + set_out.term_pull_up = 0; /* n/a as termination disabled */ + set_out.state = val; /* Output state */ + + ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG, + &set_out, sizeof(set_out)); + if (ret || set_out.gpio != 0) { + dev_err(gc->parent, + "Failed to set GPIO %u to output (%d %x)\n", off, ret, + set_out.gpio); + return ret ? ret : -EIO; + } + return 0; +} + +static int rpi_exp_gpio_get_direction(struct gpio_chip *gc, unsigned int off) +{ + struct rpi_exp_gpio *gpio; + struct gpio_get_config get; + int ret; + + gpio = gpiochip_get_data(gc); + + get.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */ + + ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG, + &get, sizeof(get)); + if (ret || get.gpio != 0) { + dev_err(gc->parent, + "Failed to get GPIO %u config (%d %x)\n", off, ret, + get.gpio); + return ret ? ret : -EIO; + } + return !get.direction; +} + +static int rpi_exp_gpio_get(struct gpio_chip *gc, unsigned int off) +{ + struct rpi_exp_gpio *gpio; + struct gpio_get_set_state get; + int ret; + + gpio = gpiochip_get_data(gc); + + get.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */ + get.state = 0; /* storage for returned value */ + + ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_STATE, + &get, sizeof(get)); + if (ret || get.gpio != 0) { + dev_err(gc->parent, + "Failed to get GPIO %u state (%d %x)\n", off, ret, + get.gpio); + return ret ? ret : -EIO; + } + return !!get.state; +} + +static void rpi_exp_gpio_set(struct gpio_chip *gc, unsigned int off, int val) +{ + struct rpi_exp_gpio *gpio; + struct gpio_get_set_state set; + int ret; + + gpio = gpiochip_get_data(gc); + + set.gpio = off + RPI_EXP_GPIO_BASE; /* GPIO to update */ + set.state = val; /* Output state */ + + ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_STATE, + &set, sizeof(set)); + if (ret || set.gpio != 0) + dev_err(gc->parent, + "Failed to set GPIO %u state (%d %x)\n", off, ret, + set.gpio); +} + +static int rpi_exp_gpio_probe(struct platform_device *pdev) +{ + int err = 0; + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct device_node *fw_node; + struct rpi_firmware *fw; + struct rpi_exp_gpio *rpi_gpio; + + fw_node = of_parse_phandle(np, "firmware", 0); + if (!fw_node) { + dev_err(dev, "Missing firmware node\n"); + return -ENOENT; + } + + fw = rpi_firmware_get(fw_node); + if (!fw) + return -EPROBE_DEFER; + + rpi_gpio = devm_kzalloc(dev, sizeof(*rpi_gpio), GFP_KERNEL); + if (!rpi_gpio) + return -ENOMEM; + + rpi_gpio->fw = fw; + rpi_gpio->gc.parent = dev; + rpi_gpio->gc.label = MODULE_NAME; + rpi_gpio->gc.owner = THIS_MODULE; + rpi_gpio->gc.of_node = np; + rpi_gpio->gc.base = -1; + rpi_gpio->gc.ngpio = NUM_GPIO; + + rpi_gpio->gc.direction_input = rpi_exp_gpio_dir_in; + rpi_gpio->gc.direction_output = rpi_exp_gpio_dir_out; + rpi_gpio->gc.get_direction = rpi_exp_gpio_get_direction; + rpi_gpio->gc.get = rpi_exp_gpio_get; + rpi_gpio->gc.set = rpi_exp_gpio_set; + rpi_gpio->gc.can_sleep = true; + + err = devm_gpiochip_add_data(dev, &rpi_gpio->gc, rpi_gpio); + if (err) + return err; + + platform_set_drvdata(pdev, rpi_gpio); + + return 0; +} + +static const struct of_device_id rpi_exp_gpio_ids[] = { + { .compatible = "raspberrypi,firmware-gpio" }, + { } +}; +MODULE_DEVICE_TABLE(of, rpi_exp_gpio_ids); + +static struct platform_driver rpi_exp_gpio_driver = { + .driver = { + .name = MODULE_NAME, + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(rpi_exp_gpio_ids), + }, + .probe = rpi_exp_gpio_probe, +}; +module_platform_driver(rpi_exp_gpio_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Dave Stevenson "); +MODULE_DESCRIPTION("Raspberry Pi 3 expander GPIO driver"); +MODULE_ALIAS("platform:rpi-exp-gpio");