1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
From 07afae52a73991a3ea948aab5d0303a5a9805b41 Mon Sep 17 00:00:00 2001
From: popcornmix <popcornmix@gmail.com>
Date: Wed, 9 Nov 2016 22:42:39 +0000
Subject: [PATCH] brcmvirt_gpio: Create coherent buffer and push to firmware
---
drivers/gpio/gpio-bcm-virt.c | 88 +++++++++++++++++++++---------
include/soc/bcm2835/raspberrypi-firmware.h | 1 +
2 files changed, 62 insertions(+), 27 deletions(-)
--- a/drivers/gpio/gpio-bcm-virt.c
+++ b/drivers/gpio/gpio-bcm-virt.c
@@ -15,6 +15,7 @@
#include <linux/module.h>
#include <linux/basic_mmio_gpio.h>
#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
#include <soc/bcm2835/raspberrypi-firmware.h>
#define MODULE_NAME "brcmvirt-gpio"
@@ -26,6 +27,7 @@ struct brcmvirt_gpio {
/* two packed 16-bit counts of enabled and disables
Allows host to detect a brief enable that was missed */
u32 enables_disables[NUM_GPIO];
+ dma_addr_t bus_addr;
};
static int brcmvirt_gpio_dir_in(struct gpio_chip *gc, unsigned off)
@@ -76,13 +78,13 @@ static void brcmvirt_gpio_set(struct gpi
static int brcmvirt_gpio_probe(struct platform_device *pdev)
{
+ int err = 0;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct device_node *fw_node;
struct rpi_firmware *fw;
struct brcmvirt_gpio *ucb;
u32 gpiovirtbuf;
- int err = 0;
fw_node = of_parse_phandle(np, "firmware", 0);
if (!fw_node) {
@@ -94,35 +96,56 @@ static int brcmvirt_gpio_probe(struct pl
if (!fw)
return -EPROBE_DEFER;
- err = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_GET_GPIOVIRTBUF,
- &gpiovirtbuf, sizeof(gpiovirtbuf));
-
- if (err) {
- dev_err(dev, "Failed to get gpiovirtbuf\n");
- goto err;
- }
-
- if (!gpiovirtbuf) {
- dev_err(dev, "No virtgpio buffer\n");
- err = -ENOENT;
- goto err;
- }
-
ucb = devm_kzalloc(dev, sizeof *ucb, GFP_KERNEL);
if (!ucb) {
err = -EINVAL;
- goto err;
+ goto out;
}
- // mmap the physical memory
- gpiovirtbuf &= ~0xc0000000;
- ucb->ts_base = ioremap(gpiovirtbuf, 4096);
- if (ucb->ts_base == NULL) {
- dev_err(dev, "Failed to map physical address\n");
- err = -ENOENT;
- goto err;
+ ucb->ts_base = dma_zalloc_coherent(NULL, PAGE_SIZE, &ucb->bus_addr, GFP_KERNEL);
+ if (!ucb->ts_base) {
+ pr_err("[%s]: failed to dma_alloc_coherent(%ld)\n",
+ __func__, PAGE_SIZE);
+ err = -ENOMEM;
+ goto out;
}
+ gpiovirtbuf = (u32)ucb->bus_addr;
+ err = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_GPIOVIRTBUF,
+ &gpiovirtbuf, sizeof(gpiovirtbuf));
+
+ if (err || gpiovirtbuf != 0) {
+ dev_warn(dev, "Failed to set gpiovirtbuf, trying to get err:%x\n", err);
+ dma_free_coherent(NULL, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
+ ucb->ts_base = 0;
+ ucb->bus_addr = 0;
+ }
+
+ if (!ucb->ts_base) {
+ err = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_GET_GPIOVIRTBUF,
+ &gpiovirtbuf, sizeof(gpiovirtbuf));
+
+ if (err) {
+ dev_err(dev, "Failed to get gpiovirtbuf\n");
+ goto out;
+ }
+
+ if (!gpiovirtbuf) {
+ dev_err(dev, "No virtgpio buffer\n");
+ err = -ENOENT;
+ goto out;
+ }
+
+ // mmap the physical memory
+ gpiovirtbuf &= ~0xc0000000;
+ ucb->ts_base = ioremap(gpiovirtbuf, 4096);
+ if (ucb->ts_base == NULL) {
+ dev_err(dev, "Failed to map physical address\n");
+ err = -ENOENT;
+ goto out;
+ }
+ ucb->bus_addr = 0;
+ }
ucb->gc.label = MODULE_NAME;
ucb->gc.owner = THIS_MODULE;
ucb->gc.dev = dev;
@@ -138,13 +161,21 @@ static int brcmvirt_gpio_probe(struct pl
err = gpiochip_add(&ucb->gc);
if (err)
- goto err;
+ goto out;
platform_set_drvdata(pdev, ucb);
-err:
+ return 0;
+out:
+ if (ucb->bus_addr) {
+ dma_free_coherent(NULL, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
+ ucb->bus_addr = 0;
+ ucb->ts_base = NULL;
+ } else if (ucb->ts_base) {
+ iounmap(ucb->ts_base);
+ ucb->ts_base = NULL;
+ }
return err;
-
}
static int brcmvirt_gpio_remove(struct platform_device *pdev)
@@ -153,7 +184,10 @@ static int brcmvirt_gpio_remove(struct p
struct brcmvirt_gpio *ucb = platform_get_drvdata(pdev);
gpiochip_remove(&ucb->gc);
- iounmap(ucb->ts_base);
+ if (ucb->bus_addr)
+ dma_free_coherent(NULL, PAGE_SIZE, ucb->ts_base, ucb->bus_addr);
+ else if (ucb->ts_base)
+ iounmap(ucb->ts_base);
return err;
}
--- a/include/soc/bcm2835/raspberrypi-firmware.h
+++ b/include/soc/bcm2835/raspberrypi-firmware.h
@@ -118,6 +118,7 @@ enum rpi_firmware_property_tag {
RPI_FIRMWARE_FRAMEBUFFER_SET_OVERSCAN = 0x0004800a,
RPI_FIRMWARE_FRAMEBUFFER_SET_PALETTE = 0x0004800b,
RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF = 0x0004801f,
+ RPI_FIRMWARE_FRAMEBUFFER_SET_GPIOVIRTBUF = 0x00048020,
RPI_FIRMWARE_FRAMEBUFFER_SET_VSYNC = 0x0004800e,
RPI_FIRMWARE_FRAMEBUFFER_SET_BACKLIGHT = 0x0004800f,
|
