target/linux/brcm2708/patches-4.14/950-0091-bcm2835-gpio-exp-Driver-for-GPIO-expander-via-mailbo.patch

   1 From 74e1aacb52fcaf5d07b5d765dca1287e4234f34d Mon Sep 17 00:00:00 2001
   2 From: Dave Stevenson <dave.stevenson@raspberrypi.org>
   3 Date: Mon, 20 Feb 2017 17:01:21 +0000
   4 Subject: [PATCH 091/454] bcm2835-gpio-exp: Driver for GPIO expander via
   5  mailbox service
   6
   7 Pi3 and Compute Module 3 have a GPIO expander that the
   8 VPU communicates with.
   9 There is a mailbox service that now allows control of this
  10 expander, so add a kernel driver that can make use of it.
  11
  12 Pwr_led node added to device-tree for Pi3.
  13
  14 Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
  15 ---
  16  drivers/gpio/Kconfig        |   7 +
  17  drivers/gpio/Makefile       |   1 +
  18  drivers/gpio/gpio-bcm-exp.c | 254 ++++++++++++++++++++++++++++++++++++
  19  3 files changed, 262 insertions(+)
  20  create mode 100644 drivers/gpio/gpio-bcm-exp.c
  21
  22 --- a/drivers/gpio/Kconfig
  23 +++ b/drivers/gpio/Kconfig
  24 @@ -128,6 +128,13 @@ config GPIO_AXP209
  25         help
  26           Say yes to enable GPIO support for the AXP209 PMIC
  27
  28 +config GPIO_BCM_EXP
  29 +       bool "Broadcom Exp GPIO"
  30 +       depends on OF_GPIO && RASPBERRYPI_FIRMWARE && (ARCH_BCM2835 || COMPILE_TEST)
  31 +       help
  32 +         Turn on GPIO support for Broadcom chips using the firmware mailbox
  33 +         to communicate with VideoCore on BCM283x chips.
  34 +
  35  config GPIO_BCM_KONA
  36         bool "Broadcom Kona GPIO"
  37         depends on OF_GPIO && (ARCH_BCM_MOBILE || COMPILE_TEST)
  38 --- a/drivers/gpio/Makefile
  39 +++ b/drivers/gpio/Makefile
  40 @@ -33,6 +33,7 @@ obj-$(CONFIG_GPIO_ARIZONA)    += gpio-arizo
  41  obj-$(CONFIG_GPIO_ATH79)       += gpio-ath79.o
  42  obj-$(CONFIG_GPIO_ASPEED)      += gpio-aspeed.o
  43  obj-$(CONFIG_GPIO_AXP209)      += gpio-axp209.o
  44 +obj-$(CONFIG_GPIO_BCM_EXP)     += gpio-bcm-exp.o
  45  obj-$(CONFIG_GPIO_BCM_KONA)    += gpio-bcm-kona.o
  46  obj-$(CONFIG_GPIO_BD9571MWV)   += gpio-bd9571mwv.o
  47  obj-$(CONFIG_GPIO_BCM_VIRT)    += gpio-bcm-virt.o
  48 --- /dev/null
  49 +++ b/drivers/gpio/gpio-bcm-exp.c
  50 @@ -0,0 +1,254 @@
  51 +/*
  52 + *  Broadcom expander GPIO driver
  53 + *
  54 + *  Uses the firmware mailbox service to communicate with the
  55 + *  GPIO expander on the VPU.
  56 + *
  57 + *  Copyright (C) 2017 Raspberry Pi Trading Ltd.
  58 + *
  59 + *  Author: Dave Stevenson <dave.stevenson@raspberrypi.org>
  60 + *  Based on gpio-bcm-virt.c by Dom Cobley <popcornmix@gmail.com>
  61 + *
  62 + * This program is free software; you can redistribute it and/or modify
  63 + * it under the terms of the GNU General Public License as published by
  64 + * the Free Software Foundation; either version 2 of the License, or
  65 + * (at your option) any later version.
  66 + */
  67 +
  68 +#include <linux/err.h>
  69 +#include <linux/gpio.h>
  70 +#include <linux/module.h>
  71 +#include <linux/platform_device.h>
  72 +#include <linux/dma-mapping.h>
  73 +#include <soc/bcm2835/raspberrypi-firmware.h>
  74 +
  75 +#define MODULE_NAME "brcmexp-gpio"
  76 +#define NUM_GPIO 8
  77 +
  78 +struct brcmexp_gpio {
  79 +       struct gpio_chip gc;
  80 +       struct device *dev;
  81 +       struct rpi_firmware *fw;
  82 +};
  83 +
  84 +struct gpio_set_config {
  85 +       u32 gpio, direction, polarity, term_en, term_pull_up, state;
  86 +};
  87 +
  88 +struct gpio_get_config {
  89 +       u32 gpio, direction, polarity, term_en, term_pull_up;
  90 +};
  91 +
  92 +struct gpio_get_set_state {
  93 +       u32 gpio, state;
  94 +};
  95 +
  96 +static int brcmexp_gpio_get_polarity(struct gpio_chip *gc, unsigned int off)
  97 +{
  98 +       struct brcmexp_gpio *gpio;
  99 +       struct gpio_get_config get;
 100 +       int ret;
 101 +
 102 +       gpio = container_of(gc, struct brcmexp_gpio, gc);
 103 +
 104 +       get.gpio = off + gpio->gc.base; /* GPIO to update */
 105 +
 106 +       ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
 107 +                                   &get, sizeof(get));
 108 +       if (ret) {
 109 +               dev_err(gpio->dev,
 110 +                       "Failed to get GPIO %u config (%d)\n", off, ret);
 111 +               return ret;
 112 +       }
 113 +       return get.polarity;
 114 +}
 115 +
 116 +static int brcmexp_gpio_dir_in(struct gpio_chip *gc, unsigned int off)
 117 +{
 118 +       struct brcmexp_gpio *gpio;
 119 +       struct gpio_set_config set_in;
 120 +       int ret;
 121 +
 122 +       gpio = container_of(gc, struct brcmexp_gpio, gc);
 123 +
 124 +       set_in.gpio = off + gpio->gc.base;      /* GPIO to update */
 125 +       set_in.direction = 0;           /* Input */
 126 +       set_in.polarity = brcmexp_gpio_get_polarity(gc, off);
 127 +                                       /* Retain existing setting */
 128 +       set_in.term_en = 0;             /* termination disabled */
 129 +       set_in.term_pull_up = 0;        /* n/a as termination disabled */
 130 +       set_in.state = 0;               /* n/a as configured as an input */
 131 +
 132 +       ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
 133 +                                   &set_in, sizeof(set_in));
 134 +       if (ret) {
 135 +               dev_err(gpio->dev,
 136 +                       "Failed to set GPIO %u to input (%d)\n",
 137 +                       off, ret);
 138 +               return ret;
 139 +       }
 140 +       return 0;
 141 +}
 142 +
 143 +static int brcmexp_gpio_dir_out(struct gpio_chip *gc, unsigned int off, int val)
 144 +{
 145 +       struct brcmexp_gpio *gpio;
 146 +       struct gpio_set_config set_out;
 147 +       int ret;
 148 +
 149 +       gpio = container_of(gc, struct brcmexp_gpio, gc);
 150 +
 151 +       set_out.gpio = off + gpio->gc.base;     /* GPIO to update */
 152 +       set_out.direction = 1;          /* Output */
 153 +       set_out.polarity = brcmexp_gpio_get_polarity(gc, off);
 154 +                                       /* Retain existing setting */
 155 +       set_out.term_en = 0;            /* n/a as an output */
 156 +       set_out.term_pull_up = 0;       /* n/a as termination disabled */
 157 +       set_out.state = val;            /* Output state */
 158 +
 159 +       ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_CONFIG,
 160 +                                   &set_out, sizeof(set_out));
 161 +       if (ret) {
 162 +               dev_err(gpio->dev,
 163 +                       "Failed to set GPIO %u to output (%d)\n", off, ret);
 164 +               return ret;
 165 +       }
 166 +       return 0;
 167 +}
 168 +
 169 +static int brcmexp_gpio_get_direction(struct gpio_chip *gc, unsigned int off)
 170 +{
 171 +       struct brcmexp_gpio *gpio;
 172 +       struct gpio_get_config get;
 173 +       int ret;
 174 +
 175 +       gpio = container_of(gc, struct brcmexp_gpio, gc);
 176 +
 177 +       get.gpio = off + gpio->gc.base; /* GPIO to update */
 178 +
 179 +       ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_CONFIG,
 180 +                                   &get, sizeof(get));
 181 +       if (ret) {
 182 +               dev_err(gpio->dev,
 183 +                       "Failed to get GPIO %u config (%d)\n", off, ret);
 184 +               return ret;
 185 +       }
 186 +       return get.direction ? GPIOF_DIR_OUT : GPIOF_DIR_IN;
 187 +}
 188 +
 189 +static int brcmexp_gpio_get(struct gpio_chip *gc, unsigned int off)
 190 +{
 191 +       struct brcmexp_gpio *gpio;
 192 +       struct gpio_get_set_state get;
 193 +       int ret;
 194 +
 195 +       gpio = container_of(gc, struct brcmexp_gpio, gc);
 196 +
 197 +       get.gpio = off + gpio->gc.base; /* GPIO to update */
 198 +       get.state = 0;          /* storage for returned value */
 199 +
 200 +       ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_GET_GPIO_STATE,
 201 +                                        &get, sizeof(get));
 202 +       if (ret) {
 203 +               dev_err(gpio->dev,
 204 +                       "Failed to get GPIO %u state (%d)\n", off, ret);
 205 +               return ret;
 206 +       }
 207 +       return !!get.state;
 208 +}
 209 +
 210 +static void brcmexp_gpio_set(struct gpio_chip *gc, unsigned int off, int val)
 211 +{
 212 +       struct brcmexp_gpio *gpio;
 213 +       struct gpio_get_set_state set;
 214 +       int ret;
 215 +
 216 +       gpio = container_of(gc, struct brcmexp_gpio, gc);
 217 +
 218 +       set.gpio = off + gpio->gc.base; /* GPIO to update */
 219 +       set.state = val;        /* Output state */
 220 +
 221 +       ret = rpi_firmware_property(gpio->fw, RPI_FIRMWARE_SET_GPIO_STATE,
 222 +                                        &set, sizeof(set));
 223 +       if (ret)
 224 +               dev_err(gpio->dev,
 225 +                       "Failed to set GPIO %u state (%d)\n", off, ret);
 226 +}
 227 +
 228 +static int brcmexp_gpio_probe(struct platform_device *pdev)
 229 +{
 230 +       int err = 0;
 231 +       struct device *dev = &pdev->dev;
 232 +       struct device_node *np = dev->of_node;
 233 +       struct device_node *fw_node;
 234 +       struct rpi_firmware *fw;
 235 +       struct brcmexp_gpio *ucb;
 236 +
 237 +       fw_node = of_parse_phandle(np, "firmware", 0);
 238 +       if (!fw_node) {
 239 +               dev_err(dev, "Missing firmware node\n");
 240 +               return -ENOENT;
 241 +       }
 242 +
 243 +       fw = rpi_firmware_get(fw_node);
 244 +       if (!fw)
 245 +               return -EPROBE_DEFER;
 246 +
 247 +       ucb = devm_kzalloc(dev, sizeof(*ucb), GFP_KERNEL);
 248 +       if (!ucb)
 249 +               return -EINVAL;
 250 +
 251 +       ucb->fw = fw;
 252 +       ucb->dev = dev;
 253 +       ucb->gc.label = MODULE_NAME;
 254 +       ucb->gc.owner = THIS_MODULE;
 255 +       ucb->gc.of_node = np;
 256 +       ucb->gc.base = 128;
 257 +       ucb->gc.ngpio = NUM_GPIO;
 258 +
 259 +       ucb->gc.direction_input = brcmexp_gpio_dir_in;
 260 +       ucb->gc.direction_output = brcmexp_gpio_dir_out;
 261 +       ucb->gc.get_direction = brcmexp_gpio_get_direction;
 262 +       ucb->gc.get = brcmexp_gpio_get;
 263 +       ucb->gc.set = brcmexp_gpio_set;
 264 +       ucb->gc.can_sleep = true;
 265 +
 266 +       err = gpiochip_add(&ucb->gc);
 267 +       if (err)
 268 +               return err;
 269 +
 270 +       platform_set_drvdata(pdev, ucb);
 271 +
 272 +       return 0;
 273 +}
 274 +
 275 +static int brcmexp_gpio_remove(struct platform_device *pdev)
 276 +{
 277 +       struct brcmexp_gpio *ucb = platform_get_drvdata(pdev);
 278 +
 279 +       gpiochip_remove(&ucb->gc);
 280 +
 281 +       return 0;
 282 +}
 283 +
 284 +static const struct of_device_id __maybe_unused brcmexp_gpio_ids[] = {
 285 +       { .compatible = "brcm,bcm2835-expgpio" },
 286 +       { }
 287 +};
 288 +MODULE_DEVICE_TABLE(of, brcmexp_gpio_ids);
 289 +
 290 +static struct platform_driver brcmexp_gpio_driver = {
 291 +       .driver = {
 292 +               .name           = MODULE_NAME,
 293 +               .owner          = THIS_MODULE,
 294 +               .of_match_table = of_match_ptr(brcmexp_gpio_ids),
 295 +       },
 296 +       .probe  = brcmexp_gpio_probe,
 297 +       .remove = brcmexp_gpio_remove,
 298 +};
 299 +module_platform_driver(brcmexp_gpio_driver);
 300 +
 301 +MODULE_LICENSE("GPL");
 302 +MODULE_AUTHOR("Dave Stevenson <dave.stevenson@raspberrypi.org>");
 303 +MODULE_DESCRIPTION("brcm-exp GPIO driver");
 304 +MODULE_ALIAS("platform:brcmexp-gpio");