OpenWrt – Blame information for rev 1

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1 office 1 From 4d08e9c723d8fcd0d86e1d779b0e720cab95383a 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 090/454] 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 3 files changed, 221 insertions(+)
13 create mode 100644 drivers/gpio/gpio-bcm-virt.c
14  
15 --- a/drivers/gpio/Kconfig
16 +++ b/drivers/gpio/Kconfig
17 @@ -134,6 +134,12 @@ config GPIO_BCM_KONA
18 help
19 Turn on GPIO support for Broadcom "Kona" chips.
20  
21 +config GPIO_BCM_VIRT
22 + bool "Broadcom Virt GPIO"
23 + depends on OF_GPIO && RASPBERRYPI_FIRMWARE && (ARCH_BCM2835 || COMPILE_TEST)
24 + help
25 + Turn on virtual GPIO support for Broadcom BCM283X chips.
26 +
27 config GPIO_BRCMSTB
28 tristate "BRCMSTB GPIO support"
29 default y if (ARCH_BRCMSTB || BMIPS_GENERIC)
30 --- a/drivers/gpio/Makefile
31 +++ b/drivers/gpio/Makefile
32 @@ -35,6 +35,7 @@ obj-$(CONFIG_GPIO_ASPEED) += gpio-aspeed
33 obj-$(CONFIG_GPIO_AXP209) += gpio-axp209.o
34 obj-$(CONFIG_GPIO_BCM_KONA) += gpio-bcm-kona.o
35 obj-$(CONFIG_GPIO_BD9571MWV) += gpio-bd9571mwv.o
36 +obj-$(CONFIG_GPIO_BCM_VIRT) += gpio-bcm-virt.o
37 obj-$(CONFIG_GPIO_BRCMSTB) += gpio-brcmstb.o
38 obj-$(CONFIG_GPIO_BT8XX) += gpio-bt8xx.o
39 obj-$(CONFIG_GPIO_CLPS711X) += gpio-clps711x.o
40 --- /dev/null
41 +++ b/drivers/gpio/gpio-bcm-virt.c
42 @@ -0,0 +1,214 @@
43 +/*
44 + * brcmvirt GPIO driver
45 + *
46 + * Copyright (C) 2012,2013 Dom Cobley <popcornmix@gmail.com>
47 + * Based on gpio-clps711x.c by Alexander Shiyan <shc_work@mail.ru>
48 + *
49 + * This program is free software; you can redistribute it and/or modify
50 + * it under the terms of the GNU General Public License as published by
51 + * the Free Software Foundation; either version 2 of the License, or
52 + * (at your option) any later version.
53 + */
54 +
55 +#include <linux/err.h>
56 +#include <linux/gpio.h>
57 +#include <linux/module.h>
58 +#include <linux/platform_device.h>
59 +#include <linux/dma-mapping.h>
60 +#include <soc/bcm2835/raspberrypi-firmware.h>
61 +
62 +#define MODULE_NAME "brcmvirt-gpio"
63 +#define NUM_GPIO 2
64 +
65 +struct brcmvirt_gpio {
66 + struct gpio_chip gc;
67 + u32 __iomem *ts_base;
68 + /* two packed 16-bit counts of enabled and disables
69 + Allows host to detect a brief enable that was missed */
70 + u32 enables_disables[NUM_GPIO];
71 + dma_addr_t bus_addr;
72 +};
73 +
74 +static int brcmvirt_gpio_dir_in(struct gpio_chip *gc, unsigned off)
75 +{
76 + struct brcmvirt_gpio *gpio;
77 + gpio = container_of(gc, struct brcmvirt_gpio, gc);
78 + return -EINVAL;
79 +}
80 +
81 +static int brcmvirt_gpio_dir_out(struct gpio_chip *gc, unsigned off, int val)
82 +{
83 + struct brcmvirt_gpio *gpio;
84 + gpio = container_of(gc, struct brcmvirt_gpio, gc);
85 + return 0;
86 +}
87 +
88 +static int brcmvirt_gpio_get(struct gpio_chip *gc, unsigned off)
89 +{
90 + struct brcmvirt_gpio *gpio;
91 + unsigned v;
92 + gpio = container_of(gc, struct brcmvirt_gpio, gc);
93 + v = readl(gpio->ts_base + off);
94 + return (v >> off) & 1;
95 +}
96 +
97 +static void brcmvirt_gpio_set(struct gpio_chip *gc, unsigned off, int val)
98 +{
99 + struct brcmvirt_gpio *gpio;
100 + u16 enables, disables;
101 + s16 diff;
102 + bool lit;
103 + gpio = container_of(gc, struct brcmvirt_gpio, gc);
104 + enables = gpio->enables_disables[off] >> 16;
105 + disables = gpio->enables_disables[off] >> 0;
106 + diff = (s16)(enables - disables);
107 + lit = diff > 0;
108 + if ((val && lit) || (!val && !lit))
109 + return;
110 + if (val)
111 + enables++;
112 + else
113 + disables++;
114 + diff = (s16)(enables - disables);
115 + BUG_ON(diff != 0 && diff != 1);
116 + gpio->enables_disables[off] = (enables << 16) | (disables << 0);
117 + writel(gpio->enables_disables[off], gpio->ts_base + off);
118 +}
119 +
120 +static int brcmvirt_gpio_probe(struct platform_device *pdev)
121 +{
122 + int err = 0;
123 + struct device *dev = &pdev->dev;
124 + struct device_node *np = dev->of_node;
125 + struct device_node *fw_node;
126 + struct rpi_firmware *fw;
127 + struct brcmvirt_gpio *ucb;
128 + u32 gpiovirtbuf;
129 +
130 + fw_node = of_parse_phandle(np, "firmware", 0);
131 + if (!fw_node) {
132 + dev_err(dev, "Missing firmware node\n");
133 + return -ENOENT;
134 + }
135 +
136 + fw = rpi_firmware_get(fw_node);
137 + if (!fw)
138 + return -EPROBE_DEFER;
139 +
140 + ucb = devm_kzalloc(dev, sizeof *ucb, GFP_KERNEL);
141 + if (!ucb) {
142 + err = -EINVAL;
143 + goto out;
144 + }
145 +
146 + ucb->ts_base = dma_zalloc_coherent(dev, PAGE_SIZE, &ucb->bus_addr, GFP_KERNEL);
147 + if (!ucb->ts_base) {
148 + pr_err("[%s]: failed to dma_alloc_coherent(%ld)\n",
149 + __func__, PAGE_SIZE);
150 + err = -ENOMEM;
151 + goto out;
152 + }
153 +
154 + gpiovirtbuf = (u32)ucb->bus_addr;
155 + err = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_GPIOVIRTBUF,
156 + &gpiovirtbuf, sizeof(gpiovirtbuf));
157 +
158 + if (err || gpiovirtbuf != 0) {
159 + dev_warn(dev, "Failed to set gpiovirtbuf, trying to get err:%x\n", err);
160 + dma_free_coherent(dev, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
161 + ucb->ts_base = 0;
162 + ucb->bus_addr = 0;
163 + }
164 +
165 + if (!ucb->ts_base) {
166 + err = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_GET_GPIOVIRTBUF,
167 + &gpiovirtbuf, sizeof(gpiovirtbuf));
168 +
169 + if (err) {
170 + dev_err(dev, "Failed to get gpiovirtbuf\n");
171 + goto out;
172 + }
173 +
174 + if (!gpiovirtbuf) {
175 + dev_err(dev, "No virtgpio buffer\n");
176 + err = -ENOENT;
177 + goto out;
178 + }
179 +
180 + // mmap the physical memory
181 + gpiovirtbuf &= ~0xc0000000;
182 + ucb->ts_base = ioremap(gpiovirtbuf, 4096);
183 + if (ucb->ts_base == NULL) {
184 + dev_err(dev, "Failed to map physical address\n");
185 + err = -ENOENT;
186 + goto out;
187 + }
188 + ucb->bus_addr = 0;
189 + }
190 + ucb->gc.label = MODULE_NAME;
191 + ucb->gc.owner = THIS_MODULE;
192 + //ucb->gc.dev = dev;
193 + ucb->gc.of_node = np;
194 + ucb->gc.base = 100;
195 + ucb->gc.ngpio = NUM_GPIO;
196 +
197 + ucb->gc.direction_input = brcmvirt_gpio_dir_in;
198 + ucb->gc.direction_output = brcmvirt_gpio_dir_out;
199 + ucb->gc.get = brcmvirt_gpio_get;
200 + ucb->gc.set = brcmvirt_gpio_set;
201 + ucb->gc.can_sleep = true;
202 +
203 + err = gpiochip_add(&ucb->gc);
204 + if (err)
205 + goto out;
206 +
207 + platform_set_drvdata(pdev, ucb);
208 +
209 + return 0;
210 +out:
211 + if (ucb->bus_addr) {
212 + dma_free_coherent(dev, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
213 + ucb->bus_addr = 0;
214 + ucb->ts_base = NULL;
215 + } else if (ucb->ts_base) {
216 + iounmap(ucb->ts_base);
217 + ucb->ts_base = NULL;
218 + }
219 + return err;
220 +}
221 +
222 +static int brcmvirt_gpio_remove(struct platform_device *pdev)
223 +{
224 + struct device *dev = &pdev->dev;
225 + int err = 0;
226 + struct brcmvirt_gpio *ucb = platform_get_drvdata(pdev);
227 +
228 + gpiochip_remove(&ucb->gc);
229 + if (ucb->bus_addr)
230 + dma_free_coherent(dev, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
231 + else if (ucb->ts_base)
232 + iounmap(ucb->ts_base);
233 + return err;
234 +}
235 +
236 +static const struct of_device_id __maybe_unused brcmvirt_gpio_ids[] = {
237 + { .compatible = "brcm,bcm2835-virtgpio" },
238 + { }
239 +};
240 +MODULE_DEVICE_TABLE(of, brcmvirt_gpio_ids);
241 +
242 +static struct platform_driver brcmvirt_gpio_driver = {
243 + .driver = {
244 + .name = MODULE_NAME,
245 + .owner = THIS_MODULE,
246 + .of_match_table = of_match_ptr(brcmvirt_gpio_ids),
247 + },
248 + .probe = brcmvirt_gpio_probe,
249 + .remove = brcmvirt_gpio_remove,
250 +};
251 +module_platform_driver(brcmvirt_gpio_driver);
252 +
253 +MODULE_LICENSE("GPL");
254 +MODULE_AUTHOR("Dom Cobley <popcornmix@gmail.com>");
255 +MODULE_DESCRIPTION("brcmvirt GPIO driver");
256 +MODULE_ALIAS("platform:brcmvirt-gpio");