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304 lines
8.3 KiB
304 lines
8.3 KiB
From 74e1aacb52fcaf5d07b5d765dca1287e4234f34d Mon Sep 17 00:00:00 2001
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From: Dave Stevenson <dave.stevenson@raspberrypi.org>
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Date: Mon, 20 Feb 2017 17:01:21 +0000
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Subject: [PATCH 091/454] bcm2835-gpio-exp: Driver for GPIO expander via
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mailbox service
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Pi3 and Compute Module 3 have a GPIO expander that the
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VPU communicates with.
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There is a mailbox service that now allows control of this
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expander, so add a kernel driver that can make use of it.
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Pwr_led node added to device-tree for Pi3.
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Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
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---
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drivers/gpio/Kconfig | 7 +
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drivers/gpio/Makefile | 1 +
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drivers/gpio/gpio-bcm-exp.c | 254 ++++++++++++++++++++++++++++++++++++
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3 files changed, 262 insertions(+)
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create mode 100644 drivers/gpio/gpio-bcm-exp.c
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--- a/drivers/gpio/Kconfig
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+++ b/drivers/gpio/Kconfig
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@@ -128,6 +128,13 @@ config GPIO_AXP209
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help
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Say yes to enable GPIO support for the AXP209 PMIC
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+config GPIO_BCM_EXP
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+ bool "Broadcom Exp GPIO"
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+ depends on OF_GPIO && RASPBERRYPI_FIRMWARE && (ARCH_BCM2835 || COMPILE_TEST)
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+ help
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+ Turn on GPIO support for Broadcom chips using the firmware mailbox
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+ to communicate with VideoCore on BCM283x chips.
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+
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config GPIO_BCM_KONA
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bool "Broadcom Kona GPIO"
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depends on OF_GPIO && (ARCH_BCM_MOBILE || COMPILE_TEST)
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--- a/drivers/gpio/Makefile
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+++ b/drivers/gpio/Makefile
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@@ -33,6 +33,7 @@ obj-$(CONFIG_GPIO_ARIZONA) += gpio-arizo
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obj-$(CONFIG_GPIO_ATH79) += gpio-ath79.o
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obj-$(CONFIG_GPIO_ASPEED) += gpio-aspeed.o
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obj-$(CONFIG_GPIO_AXP209) += gpio-axp209.o
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+obj-$(CONFIG_GPIO_BCM_EXP) += gpio-bcm-exp.o
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obj-$(CONFIG_GPIO_BCM_KONA) += gpio-bcm-kona.o
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obj-$(CONFIG_GPIO_BD9571MWV) += gpio-bd9571mwv.o
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obj-$(CONFIG_GPIO_BCM_VIRT) += gpio-bcm-virt.o
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--- /dev/null
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+++ b/drivers/gpio/gpio-bcm-exp.c
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@@ -0,0 +1,254 @@
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+/*
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+ * Broadcom expander GPIO driver
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+ *
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+ * Uses the firmware mailbox service to communicate with the
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+ * GPIO expander on the VPU.
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+ *
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+ * Copyright (C) 2017 Raspberry Pi Trading Ltd.
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+ *
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+ * Author: Dave Stevenson <dave.stevenson@raspberrypi.org>
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+ * Based on gpio-bcm-virt.c by Dom Cobley <popcornmix@gmail.com>
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+ *
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+ * This program is free software; you can redistribute it and/or modify
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+ * it under the terms of the GNU General Public License as published by
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+ * the Free Software Foundation; either version 2 of the License, or
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+ * (at your option) any later version.
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+ */
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+
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+#include <linux/err.h>
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+#include <linux/gpio.h>
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+#include <linux/module.h>
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+#include <linux/platform_device.h>
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+#include <linux/dma-mapping.h>
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+#include <soc/bcm2835/raspberrypi-firmware.h>
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+
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+#define MODULE_NAME "brcmexp-gpio"
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+#define NUM_GPIO 8
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+
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+struct brcmexp_gpio {
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+ struct gpio_chip gc;
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+ struct device *dev;
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+ struct rpi_firmware *fw;
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+};
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+
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+struct gpio_set_config {
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+ u32 gpio, direction, polarity, term_en, term_pull_up, state;
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+};
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+
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+struct gpio_get_config {
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+ u32 gpio, direction, polarity, term_en, term_pull_up;
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+};
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+
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+struct gpio_get_set_state {
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+ u32 gpio, state;
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+};
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+
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+static int brcmexp_gpio_get_polarity(struct gpio_chip *gc, unsigned int off)
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+{
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+ struct brcmexp_gpio *gpio;
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+ struct gpio_get_config get;
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+ int ret;
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+
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+ gpio = container_of(gc, struct brcmexp_gpio, gc);
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+
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+ get.gpio = off + gpio->gc.base; /* GPIO to update */
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+
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+ ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
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+ &get, sizeof(get));
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+ if (ret) {
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+ dev_err(gpio->dev,
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+ "Failed to get GPIO %u config (%d)\n", off, ret);
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+ return ret;
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+ }
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+ return get.polarity;
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+}
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+
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+static int brcmexp_gpio_dir_in(struct gpio_chip *gc, unsigned int off)
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+{
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+ struct brcmexp_gpio *gpio;
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+ struct gpio_set_config set_in;
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+ int ret;
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+
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+ gpio = container_of(gc, struct brcmexp_gpio, gc);
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+
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+ set_in.gpio = off + gpio->gc.base; /* GPIO to update */
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+ set_in.direction = 0; /* Input */
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+ set_in.polarity = brcmexp_gpio_get_polarity(gc, off);
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+ /* Retain existing setting */
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+ set_in.term_en = 0; /* termination disabled */
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+ set_in.term_pull_up = 0; /* n/a as termination disabled */
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+ set_in.state = 0; /* n/a as configured as an input */
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+
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+ ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
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+ &set_in, sizeof(set_in));
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+ if (ret) {
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+ dev_err(gpio->dev,
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+ "Failed to set GPIO %u to input (%d)\n",
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+ off, ret);
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+ return ret;
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+ }
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+ return 0;
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+}
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+
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+static int brcmexp_gpio_dir_out(struct gpio_chip *gc, unsigned int off, int val)
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+{
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+ struct brcmexp_gpio *gpio;
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+ struct gpio_set_config set_out;
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+ int ret;
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+
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+ gpio = container_of(gc, struct brcmexp_gpio, gc);
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+
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+ set_out.gpio = off + gpio->gc.base; /* GPIO to update */
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+ set_out.direction = 1; /* Output */
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+ set_out.polarity = brcmexp_gpio_get_polarity(gc, off);
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+ /* Retain existing setting */
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+ set_out.term_en = 0; /* n/a as an output */
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+ set_out.term_pull_up = 0; /* n/a as termination disabled */
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+ set_out.state = val; /* Output state */
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+
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+ ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
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+ &set_out, sizeof(set_out));
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+ if (ret) {
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+ dev_err(gpio->dev,
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+ "Failed to set GPIO %u to output (%d)\n", off, ret);
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+ return ret;
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+ }
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+ return 0;
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+}
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+
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+static int brcmexp_gpio_get_direction(struct gpio_chip *gc, unsigned int off)
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+{
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+ struct brcmexp_gpio *gpio;
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+ struct gpio_get_config get;
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+ int ret;
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+
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+ gpio = container_of(gc, struct brcmexp_gpio, gc);
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+
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+ get.gpio = off + gpio->gc.base; /* GPIO to update */
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+
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+ ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
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+ &get, sizeof(get));
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+ if (ret) {
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+ dev_err(gpio->dev,
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+ "Failed to get GPIO %u config (%d)\n", off, ret);
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+ return ret;
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+ }
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+ return get.direction ? GPIOF_DIR_OUT : GPIOF_DIR_IN;
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+}
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+
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+static int brcmexp_gpio_get(struct gpio_chip *gc, unsigned int off)
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+{
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+ struct brcmexp_gpio *gpio;
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+ struct gpio_get_set_state get;
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+ int ret;
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+
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+ gpio = container_of(gc, struct brcmexp_gpio, gc);
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+
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+ get.gpio = off + gpio->gc.base; /* GPIO to update */
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+ get.state = 0; /* storage for returned value */
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+
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+ ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_STATE,
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+ &get, sizeof(get));
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+ if (ret) {
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+ dev_err(gpio->dev,
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+ "Failed to get GPIO %u state (%d)\n", off, ret);
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+ return ret;
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+ }
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+ return !!get.state;
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+}
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+
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+static void brcmexp_gpio_set(struct gpio_chip *gc, unsigned int off, int val)
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+{
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+ struct brcmexp_gpio *gpio;
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+ struct gpio_get_set_state set;
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+ int ret;
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+
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+ gpio = container_of(gc, struct brcmexp_gpio, gc);
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+
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+ set.gpio = off + gpio->gc.base; /* GPIO to update */
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+ set.state = val; /* Output state */
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+
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+ ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_STATE,
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+ &set, sizeof(set));
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+ if (ret)
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+ dev_err(gpio->dev,
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+ "Failed to set GPIO %u state (%d)\n", off, ret);
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+}
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+
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+static int brcmexp_gpio_probe(struct platform_device *pdev)
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+{
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+ int err = 0;
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+ struct device *dev = &pdev->dev;
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+ struct device_node *np = dev->of_node;
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+ struct device_node *fw_node;
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+ struct rpi_firmware *fw;
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+ struct brcmexp_gpio *ucb;
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+
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+ fw_node = of_parse_phandle(np, "firmware", 0);
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+ if (!fw_node) {
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+ dev_err(dev, "Missing firmware node\n");
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+ return -ENOENT;
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+ }
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+
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+ fw = rpi_firmware_get(fw_node);
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+ if (!fw)
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+ return -EPROBE_DEFER;
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+
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+ ucb = devm_kzalloc(dev, sizeof(*ucb), GFP_KERNEL);
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+ if (!ucb)
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+ return -EINVAL;
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+
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+ ucb->fw = fw;
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+ ucb->dev = dev;
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+ ucb->gc.label = MODULE_NAME;
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+ ucb->gc.owner = THIS_MODULE;
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+ ucb->gc.of_node = np;
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+ ucb->gc.base = 128;
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+ ucb->gc.ngpio = NUM_GPIO;
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+
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+ ucb->gc.direction_input = brcmexp_gpio_dir_in;
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+ ucb->gc.direction_output = brcmexp_gpio_dir_out;
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+ ucb->gc.get_direction = brcmexp_gpio_get_direction;
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+ ucb->gc.get = brcmexp_gpio_get;
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+ ucb->gc.set = brcmexp_gpio_set;
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+ ucb->gc.can_sleep = true;
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+
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+ err = gpiochip_add(&ucb->gc);
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+ if (err)
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+ return err;
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+
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+ platform_set_drvdata(pdev, ucb);
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+
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+ return 0;
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+}
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+
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+static int brcmexp_gpio_remove(struct platform_device *pdev)
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+{
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+ struct brcmexp_gpio *ucb = platform_get_drvdata(pdev);
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+
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+ gpiochip_remove(&ucb->gc);
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+
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+ return 0;
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+}
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+
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+static const struct of_device_id __maybe_unused brcmexp_gpio_ids[] = {
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+ { .compatible = "brcm,bcm2835-expgpio" },
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+ { }
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+};
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+MODULE_DEVICE_TABLE(of, brcmexp_gpio_ids);
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+
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+static struct platform_driver brcmexp_gpio_driver = {
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+ .driver = {
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+ .name = MODULE_NAME,
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+ .owner = THIS_MODULE,
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+ .of_match_table = of_match_ptr(brcmexp_gpio_ids),
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+ },
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+ .probe = brcmexp_gpio_probe,
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+ .remove = brcmexp_gpio_remove,
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+};
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+module_platform_driver(brcmexp_gpio_driver);
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+
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+MODULE_LICENSE("GPL");
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+MODULE_AUTHOR("Dave Stevenson <dave.stevenson@raspberrypi.org>");
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+MODULE_DESCRIPTION("brcm-exp GPIO driver");
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+MODULE_ALIAS("platform:brcmexp-gpio");
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