target/linux/brcm2708/patches-4.9/950-0086-bcm2835-virtgpio-Virtual-GPIO-driver.patch

   1 From 1b6bee75a64ca43404e6bc8ff2fdbe8b1d0a0423 Mon Sep 17 00:00:00 2001
   2 From: popcornmix <popcornmix@gmail.com>
   3 Date: Tue, 23 Feb 2016 19:56:04 +0000
   4 Subject: [PATCH] bcm2835-virtgpio: Virtual GPIO driver
   5
   6 Add a virtual GPIO driver that uses the firmware mailbox interface to
   7 request that the VPU toggles LEDs.
   8 ---
   9  drivers/gpio/Kconfig                       |   6 +
  10  drivers/gpio/Makefile                      |   1 +
  11  drivers/gpio/gpio-bcm-virt.c               | 214 +++++++++++++++++++++++++++++
  12  include/soc/bcm2835/raspberrypi-firmware.h |   1 +
  13  4 files changed, 222 insertions(+)
  14  create mode 100644 drivers/gpio/gpio-bcm-virt.c
  15
  16 --- a/drivers/gpio/Kconfig
  17 +++ b/drivers/gpio/Kconfig
  18 @@ -134,6 +134,12 @@ config GPIO_BCM_KONA
  19         help
  20           Turn on GPIO support for Broadcom "Kona" chips.
  21
  22 +config GPIO_BCM_VIRT
  23 +       bool "Broadcom Virt GPIO"
  24 +       depends on OF_GPIO && RASPBERRYPI_FIRMWARE && (ARCH_BCM2835 || COMPILE_TEST)
  25 +       help
  26 +         Turn on virtual GPIO support for Broadcom BCM283X chips.
  27 +
  28  config GPIO_BRCMSTB
  29         tristate "BRCMSTB GPIO support"
  30         default y if (ARCH_BRCMSTB || BMIPS_GENERIC)
  31 --- a/drivers/gpio/Makefile
  32 +++ b/drivers/gpio/Makefile
  33 @@ -31,6 +31,7 @@ obj-$(CONFIG_GPIO_ATH79)      += gpio-ath79.o
  34  obj-$(CONFIG_GPIO_ASPEED)      += gpio-aspeed.o
  35  obj-$(CONFIG_GPIO_AXP209)      += gpio-axp209.o
  36  obj-$(CONFIG_GPIO_BCM_KONA)    += gpio-bcm-kona.o
  37 +obj-$(CONFIG_GPIO_BCM_VIRT)    += gpio-bcm-virt.o
  38  obj-$(CONFIG_GPIO_BRCMSTB)     += gpio-brcmstb.o
  39  obj-$(CONFIG_GPIO_BT8XX)       += gpio-bt8xx.o
  40  obj-$(CONFIG_GPIO_CLPS711X)    += gpio-clps711x.o
  41 --- /dev/null
  42 +++ b/drivers/gpio/gpio-bcm-virt.c
  43 @@ -0,0 +1,214 @@
  44 +/*
  45 + *  brcmvirt GPIO driver
  46 + *
  47 + *  Copyright (C) 2012,2013 Dom Cobley <popcornmix@gmail.com>
  48 + *  Based on gpio-clps711x.c by Alexander Shiyan <shc_work@mail.ru>
  49 + *
  50 + * This program is free software; you can redistribute it and/or modify
  51 + * it under the terms of the GNU General Public License as published by
  52 + * the Free Software Foundation; either version 2 of the License, or
  53 + * (at your option) any later version.
  54 + */
  55 +
  56 +#include <linux/err.h>
  57 +#include <linux/gpio.h>
  58 +#include <linux/module.h>
  59 +#include <linux/platform_device.h>
  60 +#include <linux/dma-mapping.h>
  61 +#include <soc/bcm2835/raspberrypi-firmware.h>
  62 +
  63 +#define MODULE_NAME "brcmvirt-gpio"
  64 +#define NUM_GPIO 2
  65 +
  66 +struct brcmvirt_gpio {
  67 +       struct gpio_chip        gc;
  68 +       u32 __iomem             *ts_base;
  69 +       /* two packed 16-bit counts of enabled and disables
  70 +           Allows host to detect a brief enable that was missed */
  71 +       u32                     enables_disables[NUM_GPIO];
  72 +       dma_addr_t              bus_addr;
  73 +};
  74 +
  75 +static int brcmvirt_gpio_dir_in(struct gpio_chip *gc, unsigned off)
  76 +{
  77 +       struct brcmvirt_gpio *gpio;
  78 +       gpio = container_of(gc, struct brcmvirt_gpio, gc);
  79 +       return -EINVAL;
  80 +}
  81 +
  82 +static int brcmvirt_gpio_dir_out(struct gpio_chip *gc, unsigned off, int val)
  83 +{
  84 +       struct brcmvirt_gpio *gpio;
  85 +       gpio = container_of(gc, struct brcmvirt_gpio, gc);
  86 +       return 0;
  87 +}
  88 +
  89 +static int brcmvirt_gpio_get(struct gpio_chip *gc, unsigned off)
  90 +{
  91 +       struct brcmvirt_gpio *gpio;
  92 +       unsigned v;
  93 +       gpio = container_of(gc, struct brcmvirt_gpio, gc);
  94 +       v = readl(gpio->ts_base + off);
  95 +       return (v >> off) & 1;
  96 +}
  97 +
  98 +static void brcmvirt_gpio_set(struct gpio_chip *gc, unsigned off, int val)
  99 +{
 100 +       struct brcmvirt_gpio *gpio;
 101 +       u16 enables, disables;
 102 +       s16 diff;
 103 +       bool lit;
 104 +       gpio = container_of(gc, struct brcmvirt_gpio, gc);
 105 +       enables  = gpio->enables_disables[off] >> 16;
 106 +       disables = gpio->enables_disables[off] >>  0;
 107 +       diff = (s16)(enables - disables);
 108 +       lit = diff > 0;
 109 +       if ((val && lit) || (!val && !lit))
 110 +               return;
 111 +       if (val)
 112 +               enables++;
 113 +       else
 114 +               disables++;
 115 +       diff = (s16)(enables - disables);
 116 +       BUG_ON(diff != 0 && diff != 1);
 117 +       gpio->enables_disables[off] = (enables << 16) | (disables << 0);
 118 +       writel(gpio->enables_disables[off], gpio->ts_base + off);
 119 +}
 120 +
 121 +static int brcmvirt_gpio_probe(struct platform_device *pdev)
 122 +{
 123 +       int err = 0;
 124 +       struct device *dev = &pdev->dev;
 125 +       struct device_node *np = dev->of_node;
 126 +       struct device_node *fw_node;
 127 +       struct rpi_firmware *fw;
 128 +       struct brcmvirt_gpio *ucb;
 129 +       u32 gpiovirtbuf;
 130 +
 131 +       fw_node = of_parse_phandle(np, "firmware", 0);
 132 +       if (!fw_node) {
 133 +               dev_err(dev, "Missing firmware node\n");
 134 +               return -ENOENT;
 135 +       }
 136 +
 137 +       fw = rpi_firmware_get(fw_node);
 138 +       if (!fw)
 139 +               return -EPROBE_DEFER;
 140 +
 141 +       ucb = devm_kzalloc(dev, sizeof *ucb, GFP_KERNEL);
 142 +       if (!ucb) {
 143 +               err = -EINVAL;
 144 +               goto out;
 145 +       }
 146 +
 147 +       ucb->ts_base = dma_zalloc_coherent(dev, PAGE_SIZE, &ucb->bus_addr, GFP_KERNEL);
 148 +       if (!ucb->ts_base) {
 149 +               pr_err("[%s]: failed to dma_alloc_coherent(%ld)\n",
 150 +                               __func__, PAGE_SIZE);
 151 +               err = -ENOMEM;
 152 +               goto out;
 153 +       }
 154 +
 155 +       gpiovirtbuf = (u32)ucb->bus_addr;
 156 +       err = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_GPIOVIRTBUF,
 157 +                                   &gpiovirtbuf, sizeof(gpiovirtbuf));
 158 +
 159 +       if (err || gpiovirtbuf != 0) {
 160 +               dev_warn(dev, "Failed to set gpiovirtbuf, trying to get err:%x\n", err);
 161 +               dma_free_coherent(dev, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
 162 +               ucb->ts_base = 0;
 163 +               ucb->bus_addr = 0;
 164 +       }
 165 +
 166 +       if (!ucb->ts_base) {
 167 +               err = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_GET_GPIOVIRTBUF,
 168 +                                           &gpiovirtbuf, sizeof(gpiovirtbuf));
 169 +
 170 +               if (err) {
 171 +                       dev_err(dev, "Failed to get gpiovirtbuf\n");
 172 +                       goto out;
 173 +               }
 174 +
 175 +               if (!gpiovirtbuf) {
 176 +                       dev_err(dev, "No virtgpio buffer\n");
 177 +                       err = -ENOENT;
 178 +                       goto out;
 179 +               }
 180 +
 181 +               // mmap the physical memory
 182 +               gpiovirtbuf &= ~0xc0000000;
 183 +               ucb->ts_base = ioremap(gpiovirtbuf, 4096);
 184 +               if (ucb->ts_base == NULL) {
 185 +                       dev_err(dev, "Failed to map physical address\n");
 186 +                       err = -ENOENT;
 187 +                       goto out;
 188 +               }
 189 +               ucb->bus_addr = 0;
 190 +       }
 191 +       ucb->gc.label = MODULE_NAME;
 192 +       ucb->gc.owner = THIS_MODULE;
 193 +       //ucb->gc.dev = dev;
 194 +       ucb->gc.of_node = np;
 195 +       ucb->gc.base = 100;
 196 +       ucb->gc.ngpio = NUM_GPIO;
 197 +
 198 +       ucb->gc.direction_input = brcmvirt_gpio_dir_in;
 199 +       ucb->gc.direction_output = brcmvirt_gpio_dir_out;
 200 +       ucb->gc.get = brcmvirt_gpio_get;
 201 +       ucb->gc.set = brcmvirt_gpio_set;
 202 +       ucb->gc.can_sleep = true;
 203 +
 204 +       err = gpiochip_add(&ucb->gc);
 205 +       if (err)
 206 +               goto out;
 207 +
 208 +       platform_set_drvdata(pdev, ucb);
 209 +
 210 +       return 0;
 211 +out:
 212 +       if (ucb->bus_addr) {
 213 +               dma_free_coherent(dev, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
 214 +               ucb->bus_addr = 0;
 215 +               ucb->ts_base = NULL;
 216 +       } else if (ucb->ts_base) {
 217 +               iounmap(ucb->ts_base);
 218 +               ucb->ts_base = NULL;
 219 +       }
 220 +       return err;
 221 +}
 222 +
 223 +static int brcmvirt_gpio_remove(struct platform_device *pdev)
 224 +{
 225 +       struct device *dev = &pdev->dev;
 226 +       int err = 0;
 227 +       struct brcmvirt_gpio *ucb = platform_get_drvdata(pdev);
 228 +
 229 +       gpiochip_remove(&ucb->gc);
 230 +       if (ucb->bus_addr)
 231 +               dma_free_coherent(dev, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
 232 +       else if (ucb->ts_base)
 233 +               iounmap(ucb->ts_base);
 234 +       return err;
 235 +}
 236 +
 237 +static const struct of_device_id __maybe_unused brcmvirt_gpio_ids[] = {
 238 +       { .compatible = "brcm,bcm2835-virtgpio" },
 239 +       { }
 240 +};
 241 +MODULE_DEVICE_TABLE(of, brcmvirt_gpio_ids);
 242 +
 243 +static struct platform_driver brcmvirt_gpio_driver = {
 244 +       .driver = {
 245 +               .name           = MODULE_NAME,
 246 +               .owner          = THIS_MODULE,
 247 +               .of_match_table = of_match_ptr(brcmvirt_gpio_ids),
 248 +       },
 249 +       .probe  = brcmvirt_gpio_probe,
 250 +       .remove = brcmvirt_gpio_remove,
 251 +};
 252 +module_platform_driver(brcmvirt_gpio_driver);
 253 +
 254 +MODULE_LICENSE("GPL");
 255 +MODULE_AUTHOR("Dom Cobley <popcornmix@gmail.com>");
 256 +MODULE_DESCRIPTION("brcmvirt GPIO driver");
 257 +MODULE_ALIAS("platform:brcmvirt-gpio");
 258 --- a/include/soc/bcm2835/raspberrypi-firmware.h
 259 +++ b/include/soc/bcm2835/raspberrypi-firmware.h
 260 @@ -116,6 +116,7 @@ enum rpi_firmware_property_tag {
 261         RPI_FIRMWARE_FRAMEBUFFER_SET_OVERSCAN =               0x0004800a,
 262         RPI_FIRMWARE_FRAMEBUFFER_SET_PALETTE =                0x0004800b,
 263         RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF =               0x0004801f,
 264 +       RPI_FIRMWARE_FRAMEBUFFER_SET_GPIOVIRTBUF =            0x00048020,
 265         RPI_FIRMWARE_FRAMEBUFFER_SET_VSYNC =                  0x0004800e,
 266         RPI_FIRMWARE_FRAMEBUFFER_SET_BACKLIGHT =              0x0004800f,
 267