From 74e1aacb52fcaf5d07b5d765dca1287e4234f34d Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Mon, 20 Feb 2017 17:01:21 +0000 Subject: [PATCH 091/454] bcm2835-gpio-exp: Driver for GPIO expander via mailbox service 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. Pwr_led node added to device-tree for Pi3. Signed-off-by: Dave Stevenson --- drivers/gpio/Kconfig | 7 + drivers/gpio/Makefile | 1 + drivers/gpio/gpio-bcm-exp.c | 254 ++++++++++++++++++++++++++++++++++++ 3 files changed, 262 insertions(+) create mode 100644 drivers/gpio/gpio-bcm-exp.c --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -128,6 +128,13 @@ config GPIO_AXP209 help Say yes to enable GPIO support for the AXP209 PMIC +config GPIO_BCM_EXP + bool "Broadcom Exp GPIO" + depends on OF_GPIO && RASPBERRYPI_FIRMWARE && (ARCH_BCM2835 || COMPILE_TEST) + help + Turn on GPIO support for Broadcom chips 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) --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -33,6 +33,7 @@ obj-$(CONFIG_GPIO_ARIZONA) += gpio-arizo obj-$(CONFIG_GPIO_ATH79) += gpio-ath79.o obj-$(CONFIG_GPIO_ASPEED) += gpio-aspeed.o obj-$(CONFIG_GPIO_AXP209) += gpio-axp209.o +obj-$(CONFIG_GPIO_BCM_EXP) += gpio-bcm-exp.o obj-$(CONFIG_GPIO_BCM_KONA) += gpio-bcm-kona.o obj-$(CONFIG_GPIO_BD9571MWV) += gpio-bd9571mwv.o obj-$(CONFIG_GPIO_BCM_VIRT) += gpio-bcm-virt.o --- /dev/null +++ b/drivers/gpio/gpio-bcm-exp.c @@ -0,0 +1,254 @@ +/* + * Broadcom expander GPIO driver + * + * Uses the firmware mailbox service to communicate with the + * GPIO expander on the VPU. + * + * Copyright (C) 2017 Raspberry Pi Trading Ltd. + * + * Author: Dave Stevenson + * Based on gpio-bcm-virt.c by Dom Cobley + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include + +#define MODULE_NAME "brcmexp-gpio" +#define NUM_GPIO 8 + +struct brcmexp_gpio { + struct gpio_chip gc; + struct device *dev; + struct rpi_firmware *fw; +}; + +struct gpio_set_config { + u32 gpio, direction, polarity, term_en, term_pull_up, state; +}; + +struct gpio_get_config { + u32 gpio, direction, polarity, term_en, term_pull_up; +}; + +struct gpio_get_set_state { + u32 gpio, state; +}; + +static int brcmexp_gpio_get_polarity(struct gpio_chip *gc, unsigned int off) +{ + struct brcmexp_gpio *gpio; + struct gpio_get_config get; + int ret; + + gpio = container_of(gc, struct brcmexp_gpio, gc); + + get.gpio = off + gpio->gc.base; /* GPIO to update */ + + ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG, + &get, sizeof(get)); + if (ret) { + dev_err(gpio->dev, + "Failed to get GPIO %u config (%d)\n", off, ret); + return ret; + } + return get.polarity; +} + +static int brcmexp_gpio_dir_in(struct gpio_chip *gc, unsigned int off) +{ + struct brcmexp_gpio *gpio; + struct gpio_set_config set_in; + int ret; + + gpio = container_of(gc, struct brcmexp_gpio, gc); + + set_in.gpio = off + gpio->gc.base; /* GPIO to update */ + set_in.direction = 0; /* Input */ + set_in.polarity = brcmexp_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) { + dev_err(gpio->dev, + "Failed to set GPIO %u to input (%d)\n", + off, ret); + return ret; + } + return 0; +} + +static int brcmexp_gpio_dir_out(struct gpio_chip *gc, unsigned int off, int val) +{ + struct brcmexp_gpio *gpio; + struct gpio_set_config set_out; + int ret; + + gpio = container_of(gc, struct brcmexp_gpio, gc); + + set_out.gpio = off + gpio->gc.base; /* GPIO to update */ + set_out.direction = 1; /* Output */ + set_out.polarity = brcmexp_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) { + dev_err(gpio->dev, + "Failed to set GPIO %u to output (%d)\n", off, ret); + return ret; + } + return 0; +} + +static int brcmexp_gpio_get_direction(struct gpio_chip *gc, unsigned int off) +{ + struct brcmexp_gpio *gpio; + struct gpio_get_config get; + int ret; + + gpio = container_of(gc, struct brcmexp_gpio, gc); + + get.gpio = off + gpio->gc.base; /* GPIO to update */ + + ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG, + &get, sizeof(get)); + if (ret) { + dev_err(gpio->dev, + "Failed to get GPIO %u config (%d)\n", off, ret); + return ret; + } + return get.direction ? GPIOF_DIR_OUT : GPIOF_DIR_IN; +} + +static int brcmexp_gpio_get(struct gpio_chip *gc, unsigned int off) +{ + struct brcmexp_gpio *gpio; + struct gpio_get_set_state get; + int ret; + + gpio = container_of(gc, struct brcmexp_gpio, gc); + + get.gpio = off + gpio->gc.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) { + dev_err(gpio->dev, + "Failed to get GPIO %u state (%d)\n", off, ret); + return ret; + } + return !!get.state; +} + +static void brcmexp_gpio_set(struct gpio_chip *gc, unsigned int off, int val) +{ + struct brcmexp_gpio *gpio; + struct gpio_get_set_state set; + int ret; + + gpio = container_of(gc, struct brcmexp_gpio, gc); + + set.gpio = off + gpio->gc.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) + dev_err(gpio->dev, + "Failed to set GPIO %u state (%d)\n", off, ret); +} + +static int brcmexp_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 brcmexp_gpio *ucb; + + 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; + + ucb = devm_kzalloc(dev, sizeof(*ucb), GFP_KERNEL); + if (!ucb) + return -EINVAL; + + ucb->fw = fw; + ucb->dev = dev; + ucb->gc.label = MODULE_NAME; + ucb->gc.owner = THIS_MODULE; + ucb->gc.of_node = np; + ucb->gc.base = 128; + ucb->gc.ngpio = NUM_GPIO; + + ucb->gc.direction_input = brcmexp_gpio_dir_in; + ucb->gc.direction_output = brcmexp_gpio_dir_out; + ucb->gc.get_direction = brcmexp_gpio_get_direction; + ucb->gc.get = brcmexp_gpio_get; + ucb->gc.set = brcmexp_gpio_set; + ucb->gc.can_sleep = true; + + err = gpiochip_add(&ucb->gc); + if (err) + return err; + + platform_set_drvdata(pdev, ucb); + + return 0; +} + +static int brcmexp_gpio_remove(struct platform_device *pdev) +{ + struct brcmexp_gpio *ucb = platform_get_drvdata(pdev); + + gpiochip_remove(&ucb->gc); + + return 0; +} + +static const struct of_device_id __maybe_unused brcmexp_gpio_ids[] = { + { .compatible = "brcm,bcm2835-expgpio" }, + { } +}; +MODULE_DEVICE_TABLE(of, brcmexp_gpio_ids); + +static struct platform_driver brcmexp_gpio_driver = { + .driver = { + .name = MODULE_NAME, + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(brcmexp_gpio_ids), + }, + .probe = brcmexp_gpio_probe, + .remove = brcmexp_gpio_remove, +}; +module_platform_driver(brcmexp_gpio_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Dave Stevenson "); +MODULE_DESCRIPTION("brcm-exp GPIO driver"); +MODULE_ALIAS("platform:brcmexp-gpio");