1 // SPDX-License-Identifier: GPL-2.0-only
3  * Sloppy logic analyzer using GPIOs (to be run on an isolated CPU)
5  * Use the 'gpio-sloppy-logic-analyzer' script in the 'tools/gpio' folder for
7  * analyzer which can be affected by latencies and non-deterministic code
11  * Copyright (C) Wolfram Sang <wsa@sang-engineering.com>
34 #define GPIO_LA_NAME "gpio-sloppy-logic-analyzer"
61 	ret = gpiod_get_array_value(d->ndescs, d->desc, d->info, sptr);  in gpio_la_get_array()
63 		ret = -EINTR;  in gpio_la_get_array()
71 	u8 *la_buf = priv->blob.data;  in fops_capture_set()
82 		return -ENOMEM;  in fops_capture_set()
84 	if (!priv->delay_ns)  in fops_capture_set()
85 		return -EINVAL;  in fops_capture_set()
87 	mutex_lock(&priv->blob_lock);  in fops_capture_set()
88 	if (priv->blob_dent) {  in fops_capture_set()
89 		debugfs_remove(priv->blob_dent);  in fops_capture_set()
90 		priv->blob_dent = NULL;  in fops_capture_set()
93 	priv->buf_idx = 0;  in fops_capture_set()
98 	/* Measure delay of reading GPIOs */  in fops_capture_set()
101 		ret = gpio_la_get_array(priv->descs, &state);  in fops_capture_set()
103 			goto out;  in fops_capture_set()
106 	priv->acq_delay = ktime_sub(ktime_get(), start_time) / GPIO_LA_NUM_TESTS;  in fops_capture_set()
107 	if (priv->delay_ns < priv->acq_delay) {  in fops_capture_set()
108 		ret = -ERANGE;  in fops_capture_set()
109 		goto out;  in fops_capture_set()
112 	delay = priv->delay_ns - priv->acq_delay;  in fops_capture_set()
115 	for (i = 0; i < priv->trig_len; i += 2) {  in fops_capture_set()
117 			ret = gpio_la_get_array(priv->descs, &state);  in fops_capture_set()
119 				goto out;  in fops_capture_set()
122 		} while ((state & priv->trig_data[i]) != priv->trig_data[i + 1]);  in fops_capture_set()
126 	if (priv->trig_len)  in fops_capture_set()
127 		la_buf[priv->buf_idx++] = state;  in fops_capture_set()
130 	while (priv->buf_idx < priv->blob.size) {  in fops_capture_set()
131 		ret = gpio_la_get_array(priv->descs, &state);  in fops_capture_set()
133 			goto out;  in fops_capture_set()
135 		la_buf[priv->buf_idx++] = state;  in fops_capture_set()
138 out:  in fops_capture_set()
142 		dev_err(priv->dev, "couldn't read GPIOs: %d\n", ret);  in fops_capture_set()
144 	kfree(priv->trig_data);  in fops_capture_set()
145 	priv->trig_data = NULL;  in fops_capture_set()
146 	priv->trig_len = 0;  in fops_capture_set()
148 	priv->blob_dent = debugfs_create_blob("sample_data", 0400, priv->debug_dir, &priv->blob);  in fops_capture_set()
149 	mutex_unlock(&priv->blob_lock);  in fops_capture_set()
159 	*val = priv->blob.size;  in fops_buf_size_get()
171 		return -EINVAL;  in fops_buf_size_set()
173 	mutex_lock(&priv->blob_lock);  in fops_buf_size_set()
175 	vfree(priv->blob.data);  in fops_buf_size_set()
179 		ret = -ENOMEM;  in fops_buf_size_set()
182 	priv->blob.data = p;  in fops_buf_size_set()
183 	priv->blob.size = val;  in fops_buf_size_set()
185 	mutex_unlock(&priv->blob_lock);  in fops_buf_size_set()
192 	return single_open(file, NULL, inode->i_private);  in trigger_open()
198 	struct seq_file *m = file->private_data;  in trigger_write()
199 	struct gpio_la_poll_priv *priv = m->private;  in trigger_write()
204 		return -EINVAL;  in trigger_write()
210 	priv->trig_data = buf;  in trigger_write()
211 	priv->trig_len = count;  in trigger_write()
226 	struct device *dev = &pdev->dev;  in gpio_la_poll_probe()
235 		return -ENOMEM;  in gpio_la_poll_probe()
237 	ret = devm_mutex_init(dev, &priv->blob_lock);  in gpio_la_poll_probe()
243 	priv->descs = devm_gpiod_get_array(dev, "probe", GPIOD_IN);  in gpio_la_poll_probe()
244 	if (IS_ERR(priv->descs))  in gpio_la_poll_probe()
245 		return PTR_ERR(priv->descs);  in gpio_la_poll_probe()
248 	if (priv->descs->ndescs > GPIO_LA_MAX_PROBES)  in gpio_la_poll_probe()
249 		return -EFBIG;  in gpio_la_poll_probe()
251 	ret = device_property_read_string_array(dev, "probe-names", gpio_names,  in gpio_la_poll_probe()
252 						priv->descs->ndescs);  in gpio_la_poll_probe()
253 	if (ret >= 0 && ret != priv->descs->ndescs)  in gpio_la_poll_probe()
254 		ret = -EBADR;  in gpio_la_poll_probe()
256 		return dev_err_probe(dev, ret, "error naming the GPIOs");  in gpio_la_poll_probe()
258 	for (i = 0; i < priv->descs->ndescs; i++) {  in gpio_la_poll_probe()
262 		if (gpiod_cansleep(priv->descs->desc[i]))  in gpio_la_poll_probe()
263 			return -EREMOTE;  in gpio_la_poll_probe()
267 			return -ENOMEM;  in gpio_la_poll_probe()
268 		gpiod_set_consumer_name(priv->descs->desc[i], consumer_name);  in gpio_la_poll_probe()
276 			return -ENOMEM;  in gpio_la_poll_probe()
284 	priv->dev = dev;  in gpio_la_poll_probe()
286 	priv->meta.data = meta;  in gpio_la_poll_probe()
287 	priv->meta.size = meta_len;  in gpio_la_poll_probe()
288 	priv->debug_dir = debugfs_create_dir(devname, gpio_la_poll_debug_dir);  in gpio_la_poll_probe()
289 	debugfs_create_blob("meta_data", 0400, priv->debug_dir, &priv->meta);  in gpio_la_poll_probe()
290 	debugfs_create_ulong("delay_ns", 0600, priv->debug_dir, &priv->delay_ns);  in gpio_la_poll_probe()
291 	debugfs_create_ulong("delay_ns_acquisition", 0400, priv->debug_dir, &priv->acq_delay);  in gpio_la_poll_probe()
292 	debugfs_create_file_unsafe("buf_size", 0600, priv->debug_dir, priv, &fops_buf_size);  in gpio_la_poll_probe()
293 	debugfs_create_file_unsafe("capture", 0200, priv->debug_dir, priv, &fops_capture);  in gpio_la_poll_probe()
294 	debugfs_create_file_unsafe("trigger", 0200, priv->debug_dir, priv, &fops_trigger);  in gpio_la_poll_probe()
303 	mutex_lock(&priv->blob_lock);  in gpio_la_poll_remove()
304 	debugfs_remove_recursive(priv->debug_dir);  in gpio_la_poll_remove()
305 	mutex_unlock(&priv->blob_lock);  in gpio_la_poll_remove()
330  * Non-strict pin controllers can read GPIOs while being muxed to something else.
331  * To support that, we need to claim GPIOs before further pinmuxing happens. So,
343 MODULE_AUTHOR("Wolfram Sang <wsa@sang-engineering.com>");
344 MODULE_DESCRIPTION("Sloppy logic analyzer using GPIOs");