target/linux/brcm2708/patches-4.4/0166-bcm2835-virtgpio-Virtual-GPIO-driver.patch

   1 From 5e3c3e845f998f86c2f22017576cb19e5d7fe9bb 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 166/170] 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  arch/arm/configs/bcm2709_defconfig         |   1 +
  10  drivers/gpio/Kconfig                       |   6 +
  11  drivers/gpio/Makefile                      |   1 +
  12  drivers/gpio/gpio-bcm-virt.c               | 180 +++++++++++++++++++++++++++++
  13  include/soc/bcm2835/raspberrypi-firmware.h |   1 +
  14  5 files changed, 189 insertions(+)
  15  create mode 100644 drivers/gpio/gpio-bcm-virt.c
  16
  17 --- a/arch/arm/configs/bcm2709_defconfig
  18 +++ b/arch/arm/configs/bcm2709_defconfig
  19 @@ -607,6 +607,7 @@ CONFIG_PPS=m
  20  CONFIG_PPS_CLIENT_LDISC=m
  21  CONFIG_PPS_CLIENT_GPIO=m
  22  CONFIG_GPIO_SYSFS=y
  23 +CONFIG_GPIO_BCM_VIRT=y
  24  CONFIG_GPIO_ARIZONA=m
  25  CONFIG_GPIO_STMPE=y
  26  CONFIG_W1=m
  27 --- a/drivers/gpio/Kconfig
  28 +++ b/drivers/gpio/Kconfig
  29 @@ -132,6 +132,12 @@ config GPIO_BCM_KONA
  30         help
  31           Turn on GPIO support for Broadcom "Kona" chips.
  32
  33 +config GPIO_BCM_VIRT
  34 +       bool "Broadcom Virt GPIO"
  35 +       depends on OF_GPIO && RASPBERRYPI_FIRMWARE && (ARCH_BCM2835 || ARCH_BCM2708 || ARCH_BCM2709 || COMPILE_TEST)
  36 +       help
  37 +         Turn on virtual GPIO support for Broadcom BCM283X chips.
  38 +
  39  config GPIO_BRCMSTB
  40         tristate "BRCMSTB GPIO support"
  41         default y if ARCH_BRCMSTB
  42 --- a/drivers/gpio/Makefile
  43 +++ b/drivers/gpio/Makefile
  44 @@ -24,6 +24,7 @@ obj-$(CONFIG_GPIO_AMDPT)      += gpio-amdpt.o
  45  obj-$(CONFIG_GPIO_ARIZONA)     += gpio-arizona.o
  46  obj-$(CONFIG_ATH79)            += gpio-ath79.o
  47  obj-$(CONFIG_GPIO_BCM_KONA)    += gpio-bcm-kona.o
  48 +obj-$(CONFIG_GPIO_BCM_VIRT)    += gpio-bcm-virt.o
  49  obj-$(CONFIG_GPIO_BRCMSTB)     += gpio-brcmstb.o
  50  obj-$(CONFIG_GPIO_BT8XX)       += gpio-bt8xx.o
  51  obj-$(CONFIG_GPIO_CLPS711X)    += gpio-clps711x.o
  52 --- /dev/null
  53 +++ b/drivers/gpio/gpio-bcm-virt.c
  54 @@ -0,0 +1,180 @@
  55 +/*
  56 + *  brcmvirt GPIO driver
  57 + *
  58 + *  Copyright (C) 2012,2013 Dom Cobley <popcornmix@gmail.com>
  59 + *  Based on gpio-clps711x.c by Alexander Shiyan <shc_work@mail.ru>
  60 + *
  61 + * This program is free software; you can redistribute it and/or modify
  62 + * it under the terms of the GNU General Public License as published by
  63 + * the Free Software Foundation; either version 2 of the License, or
  64 + * (at your option) any later version.
  65 + */
  66 +
  67 +#include <linux/err.h>
  68 +#include <linux/gpio.h>
  69 +#include <linux/module.h>
  70 +#include <linux/basic_mmio_gpio.h>
  71 +#include <linux/platform_device.h>
  72 +#include <soc/bcm2835/raspberrypi-firmware.h>
  73 +
  74 +#define MODULE_NAME "brcmvirt-gpio"
  75 +#define NUM_GPIO 2
  76 +
  77 +struct brcmvirt_gpio {
  78 +       struct gpio_chip        gc;
  79 +       u32 __iomem             *ts_base;
  80 +       /* two packed 16-bit counts of enabled and disables
  81 +           Allows host to detect a brief enable that was missed */
  82 +       u32                     enables_disables[NUM_GPIO];
  83 +};
  84 +
  85 +static int brcmvirt_gpio_dir_in(struct gpio_chip *gc, unsigned off)
  86 +{
  87 +       struct brcmvirt_gpio *gpio;
  88 +       gpio = container_of(gc, struct brcmvirt_gpio, gc);
  89 +       return -EINVAL;
  90 +}
  91 +
  92 +static int brcmvirt_gpio_dir_out(struct gpio_chip *gc, unsigned off, int val)
  93 +{
  94 +       struct brcmvirt_gpio *gpio;
  95 +       gpio = container_of(gc, struct brcmvirt_gpio, gc);
  96 +       return 0;
  97 +}
  98 +
  99 +static int brcmvirt_gpio_get(struct gpio_chip *gc, unsigned off)
 100 +{
 101 +       struct brcmvirt_gpio *gpio;
 102 +       unsigned v;
 103 +       gpio = container_of(gc, struct brcmvirt_gpio, gc);
 104 +       v = readl(gpio->ts_base + off);
 105 +       return (v >> off) & 1;
 106 +}
 107 +
 108 +static void brcmvirt_gpio_set(struct gpio_chip *gc, unsigned off, int val)
 109 +{
 110 +       struct brcmvirt_gpio *gpio;
 111 +       u16 enables, disables;
 112 +       s16 diff;
 113 +       bool lit;
 114 +       gpio = container_of(gc, struct brcmvirt_gpio, gc);
 115 +       enables  = gpio->enables_disables[off] >> 16;
 116 +       disables = gpio->enables_disables[off] >>  0;
 117 +       diff = (s16)(enables - disables);
 118 +       lit = diff > 0;
 119 +       if ((val && lit) || (!val && !lit))
 120 +               return;
 121 +       if (val)
 122 +               enables++;
 123 +       else
 124 +               disables++;
 125 +       diff = (s16)(enables - disables);
 126 +       BUG_ON(diff != 0 && diff != 1);
 127 +       gpio->enables_disables[off] = (enables << 16) | (disables << 0);
 128 +       writel(gpio->enables_disables[off], gpio->ts_base + off);
 129 +}
 130 +
 131 +static int brcmvirt_gpio_probe(struct platform_device *pdev)
 132 +{
 133 +       struct device *dev = &pdev->dev;
 134 +       struct device_node *np = dev->of_node;
 135 +       struct device_node *fw_node;
 136 +       struct rpi_firmware *fw;
 137 +       struct brcmvirt_gpio *ucb;
 138 +       u32 gpiovirtbuf;
 139 +       int err = 0;
 140 +
 141 +       fw_node = of_parse_phandle(np, "firmware", 0);
 142 +       if (!fw_node) {
 143 +               dev_err(dev, "Missing firmware node\n");
 144 +               return -ENOENT;
 145 +       }
 146 +
 147 +       fw = rpi_firmware_get(fw_node);
 148 +       if (!fw)
 149 +               return -EPROBE_DEFER;
 150 +
 151 +       err = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_GET_GPIOVIRTBUF,
 152 +                                   &gpiovirtbuf, sizeof(gpiovirtbuf));
 153 +
 154 +       if (err) {
 155 +               dev_err(dev, "Failed to get gpiovirtbuf\n");
 156 +               goto err;
 157 +       }
 158 +
 159 +       if (!gpiovirtbuf) {
 160 +               dev_err(dev, "No virtgpio buffer\n");
 161 +               err = -ENOENT;
 162 +               goto err;
 163 +       }
 164 +
 165 +       ucb = devm_kzalloc(dev, sizeof *ucb, GFP_KERNEL);
 166 +       if (!ucb) {
 167 +               err = -EINVAL;
 168 +               goto err;
 169 +       }
 170 +
 171 +       // mmap the physical memory
 172 +       gpiovirtbuf &= ~0xc0000000;
 173 +       ucb->ts_base = ioremap(gpiovirtbuf, 4096);
 174 +       if (ucb->ts_base == NULL) {
 175 +               dev_err(dev, "Failed to map physical address\n");
 176 +               err = -ENOENT;
 177 +               goto err;
 178 +       }
 179 +
 180 +       ucb->gc.label = MODULE_NAME;
 181 +       ucb->gc.owner = THIS_MODULE;
 182 +       ucb->gc.dev = dev;
 183 +       ucb->gc.of_node = np;
 184 +       ucb->gc.base = 100;
 185 +       ucb->gc.ngpio = NUM_GPIO;
 186 +
 187 +       ucb->gc.direction_input = brcmvirt_gpio_dir_in;
 188 +       ucb->gc.direction_output = brcmvirt_gpio_dir_out;
 189 +       ucb->gc.get = brcmvirt_gpio_get;
 190 +       ucb->gc.set = brcmvirt_gpio_set;
 191 +       ucb->gc.can_sleep = true;
 192 +
 193 +       err = gpiochip_add(&ucb->gc);
 194 +       if (err)
 195 +               goto err;
 196 +
 197 +       platform_set_drvdata(pdev, ucb);
 198 +
 199 +err:
 200 +       return err;
 201 +
 202 +}
 203 +
 204 +static int brcmvirt_gpio_remove(struct platform_device *pdev)
 205 +{
 206 +       int err = 0;
 207 +       struct brcmvirt_gpio *ucb = platform_get_drvdata(pdev);
 208 +
 209 +       gpiochip_remove(&ucb->gc);
 210 +       iounmap(ucb->ts_base);
 211 +       return err;
 212 +}
 213 +
 214 +static const struct of_device_id __maybe_unused brcmvirt_gpio_ids[] = {
 215 +       { .compatible = "brcm,bcm2835-virtgpio" },
 216 +       { }
 217 +};
 218 +MODULE_DEVICE_TABLE(of, brcmvirt_gpio_ids);
 219 +
 220 +static struct platform_driver brcmvirt_gpio_driver = {
 221 +       .driver = {
 222 +               .name           = MODULE_NAME,
 223 +               .owner          = THIS_MODULE,
 224 +               .of_match_table = of_match_ptr(brcmvirt_gpio_ids),
 225 +       },
 226 +       .probe  = brcmvirt_gpio_probe,
 227 +       .remove = brcmvirt_gpio_remove,
 228 +};
 229 +module_platform_driver(brcmvirt_gpio_driver);
 230 +
 231 +MODULE_LICENSE("GPL");
 232 +MODULE_AUTHOR("Dom Cobley <popcornmix@gmail.com>");
 233 +MODULE_DESCRIPTION("brcmvirt GPIO driver");
 234 +MODULE_ALIAS("platform:brcmvirt-gpio");
 235 --- a/include/soc/bcm2835/raspberrypi-firmware.h
 236 +++ b/include/soc/bcm2835/raspberrypi-firmware.h
 237 @@ -93,6 +93,7 @@ enum rpi_firmware_property_tag {
 238         RPI_FIRMWARE_FRAMEBUFFER_GET_OVERSCAN =               0x0004000a,
 239         RPI_FIRMWARE_FRAMEBUFFER_GET_PALETTE =                0x0004000b,
 240         RPI_FIRMWARE_FRAMEBUFFER_GET_TOUCHBUF =               0x0004000f,
 241 +       RPI_FIRMWARE_FRAMEBUFFER_GET_GPIOVIRTBUF =            0x00040010,
 242         RPI_FIRMWARE_FRAMEBUFFER_RELEASE =                    0x00048001,
 243         RPI_FIRMWARE_FRAMEBUFFER_TEST_PHYSICAL_WIDTH_HEIGHT = 0x00044003,
 244         RPI_FIRMWARE_FRAMEBUFFER_TEST_VIRTUAL_WIDTH_HEIGHT =  0x00044004,