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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2021-2022 NVIDIA Corporation
*
* Author: Dipen Patel <dipenp@nvidia.com>
*/
#include <linux/version.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <linux/timer.h>
#include <linux/platform_device.h>
#include <linux/workqueue.h>
#include <linux/hte.h>
/*
* This sample HTE GPIO test driver demonstrates HTE API usage by enabling
* hardware timestamp on gpio_in and specified LIC IRQ lines.
*
* Note: gpio_out and gpio_in need to be shorted externally in order for this
* test driver to work for the GPIO monitoring. The test driver has been
* tested on Jetson AGX Xavier platform by shorting pin 32 and 16 on 40 pin
* header.
*
* Device tree snippet to activate this driver:
* tegra_hte_test {
* compatible = "nvidia,tegra194-hte-test";
* in-gpio = <&gpio_aon TEGRA194_AON_GPIO(BB, 1)>;
* out-gpio = <&gpio_aon TEGRA194_AON_GPIO(BB, 0)>;
* timestamps = <&tegra_hte_aon TEGRA194_AON_GPIO(BB, 1)>,
* <&tegra_hte_lic 0x19>;
* timestamp-names = "hte-gpio", "hte-i2c-irq";
* status = "okay";
* };
*
* How to run test driver:
* - Load test driver.
* - For the GPIO, at regular interval gpio_out pin toggles triggering
* HTE for rising edge on gpio_in pin.
*
* - For the LIC IRQ line, it uses 0x19 interrupt which is i2c controller 1.
* - Run i2cdetect -y 1 1>/dev/null, this command will generate i2c bus
* transactions which creates timestamp data.
* - It prints below message for both the lines.
* HW timestamp(<line id>:<ts seq number>): <timestamp>, edge: <edge>.
* - Unloading the driver disables and deallocate the HTE.
*/
static struct tegra_hte_test {
int gpio_in_irq;
struct device *pdev;
struct gpio_desc *gpio_in;
struct gpio_desc *gpio_out;
struct hte_ts_desc *desc;
struct timer_list timer;
struct kobject *kobj;
} hte;
static enum hte_return process_hw_ts(struct hte_ts_data *ts, void *p)
{
char *edge;
struct hte_ts_desc *desc = p;
if (!ts || !p)
return HTE_CB_HANDLED;
if (ts->raw_level < 0)
edge = "Unknown";
pr_info("HW timestamp(%u: %llu): %llu, edge: %s\n",
desc->attr.line_id, ts->seq, ts->tsc,
(ts->raw_level >= 0) ? ((ts->raw_level == 0) ?
"falling" : "rising") : edge);
return HTE_CB_HANDLED;
}
static void gpio_timer_cb(struct timer_list *t)
{
(void)t;
gpiod_set_value(hte.gpio_out, !gpiod_get_value(hte.gpio_out));
mod_timer(&hte.timer, jiffies + msecs_to_jiffies(8000));
}
static irqreturn_t tegra_hte_test_gpio_isr(int irq, void *data)
{
(void)irq;
(void)data;
return IRQ_HANDLED;
}
static const struct of_device_id tegra_hte_test_of_match[] = {
{ .compatible = "nvidia,tegra194-hte-test"},
{ }
};
MODULE_DEVICE_TABLE(of, tegra_hte_test_of_match);
static int tegra_hte_test_probe(struct platform_device *pdev)
{
int ret = 0;
int i, cnt;
dev_set_drvdata(&pdev->dev, &hte);
hte.pdev = &pdev->dev;
hte.gpio_out = gpiod_get(&pdev->dev, "out", 0);
if (IS_ERR(hte.gpio_out)) {
dev_err(&pdev->dev, "failed to get gpio out\n");
ret = -EINVAL;
goto out;
}
hte.gpio_in = gpiod_get(&pdev->dev, "in", 0);
if (IS_ERR(hte.gpio_in)) {
dev_err(&pdev->dev, "failed to get gpio in\n");
ret = -EINVAL;
goto free_gpio_out;
}
ret = gpiod_direction_output(hte.gpio_out, 0);
if (ret) {
dev_err(&pdev->dev, "failed to set output\n");
ret = -EINVAL;
goto free_gpio_in;
}
ret = gpiod_direction_input(hte.gpio_in);
if (ret) {
dev_err(&pdev->dev, "failed to set input\n");
ret = -EINVAL;
goto free_gpio_in;
}
ret = gpiod_to_irq(hte.gpio_in);
if (ret < 0) {
dev_err(&pdev->dev, "failed to map GPIO to IRQ: %d\n", ret);
ret = -ENXIO;
goto free_gpio_in;
}
hte.gpio_in_irq = ret;
ret = request_irq(ret, tegra_hte_test_gpio_isr,
IRQF_TRIGGER_RISING,
"tegra_hte_gpio_test_isr", &hte);
if (ret) {
dev_err(&pdev->dev, "failed to acquire IRQ\n");
ret = -ENXIO;
goto free_irq;
}
cnt = of_hte_req_count(hte.pdev);
if (cnt < 0)
goto free_irq;
dev_info(&pdev->dev, "Total requested lines:%d\n", cnt);
hte.desc = devm_kzalloc(hte.pdev, sizeof(*hte.desc) * cnt, GFP_KERNEL);
if (!hte.desc) {
ret = -ENOMEM;
goto free_irq;
}
for (i = 0; i < cnt; i++) {
if (i == 0)
/*
* GPIO hte init, line_id and name will be parsed from
* the device tree node. The edge_flag is implicitly
* set by request_irq call. Only line_data is needed to be
* set.
*/
hte_init_line_attr(&hte.desc[i], 0, 0, NULL,
hte.gpio_in);
else
/*
* same comment as above except that IRQ does not need
* line data.
*/
hte_init_line_attr(&hte.desc[i], 0, 0, NULL, NULL);
ret = hte_ts_get(hte.pdev, &hte.desc[i], i);
if (ret)
goto ts_put;
ret = devm_hte_request_ts_ns(hte.pdev, &hte.desc[i],
process_hw_ts, NULL,
&hte.desc[i]);
if (ret) /* no need to ts_put, request API takes care */
goto free_irq;
}
timer_setup(&hte.timer, gpio_timer_cb, 0);
mod_timer(&hte.timer, jiffies + msecs_to_jiffies(5000));
return 0;
ts_put:
cnt = i;
for (i = 0; i < cnt; i++)
hte_ts_put(&hte.desc[i]);
free_irq:
free_irq(hte.gpio_in_irq, &hte);
free_gpio_in:
gpiod_put(hte.gpio_in);
free_gpio_out:
gpiod_put(hte.gpio_out);
out:
return ret;
}
static int tegra_hte_test_remove(struct platform_device *pdev)
{
(void)pdev;
free_irq(hte.gpio_in_irq, &hte);
gpiod_put(hte.gpio_in);
gpiod_put(hte.gpio_out);
del_timer(&hte.timer);
return 0;
}
static struct platform_driver tegra_hte_test_driver = {
.probe = tegra_hte_test_probe,
.remove = tegra_hte_test_remove,
.driver = {
.name = "tegra_hte_test",
.of_match_table = tegra_hte_test_of_match,
},
};
module_platform_driver(tegra_hte_test_driver);
MODULE_AUTHOR("Dipen Patel <dipenp@nvidia.com>");
MODULE_LICENSE("GPL");
|