xref: /linux/drivers/hwtracing/coresight/coresight-tpda.c (revision 6e7fd890f1d6ac83805409e9c346240de2705584)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
4  */
5 
6 #include <linux/amba/bus.h>
7 #include <linux/bitfield.h>
8 #include <linux/coresight.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/fs.h>
12 #include <linux/io.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/platform_device.h>
17 
18 #include "coresight-priv.h"
19 #include "coresight-tpda.h"
20 #include "coresight-trace-id.h"
21 #include "coresight-tpdm.h"
22 
23 DEFINE_CORESIGHT_DEVLIST(tpda_devs, "tpda");
24 
25 static bool coresight_device_is_tpdm(struct coresight_device *csdev)
26 {
27 	return (csdev->type == CORESIGHT_DEV_TYPE_SOURCE) &&
28 	       (csdev->subtype.source_subtype ==
29 			CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM);
30 }
31 
32 static void tpda_clear_element_size(struct coresight_device *csdev)
33 {
34 	struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
35 
36 	drvdata->dsb_esize = 0;
37 	drvdata->cmb_esize = 0;
38 }
39 
40 static void tpda_set_element_size(struct tpda_drvdata *drvdata, u32 *val)
41 {
42 	/* Clear all relevant fields */
43 	*val &= ~(TPDA_Pn_CR_DSBSIZE | TPDA_Pn_CR_CMBSIZE);
44 
45 	if (drvdata->dsb_esize == 64)
46 		*val |= TPDA_Pn_CR_DSBSIZE;
47 	else if (drvdata->dsb_esize == 32)
48 		*val &= ~TPDA_Pn_CR_DSBSIZE;
49 
50 	if (drvdata->cmb_esize == 64)
51 		*val |= FIELD_PREP(TPDA_Pn_CR_CMBSIZE, 0x2);
52 	else if (drvdata->cmb_esize == 32)
53 		*val |= FIELD_PREP(TPDA_Pn_CR_CMBSIZE, 0x1);
54 	else if (drvdata->cmb_esize == 8)
55 		*val &= ~TPDA_Pn_CR_CMBSIZE;
56 }
57 
58 /*
59  * Read the element size from the TPDM device. One TPDM must have at least one of the
60  * element size property.
61  * Returns
62  *    0 - The element size property is read
63  *    Others - Cannot read the property of the element size
64  */
65 static int tpdm_read_element_size(struct tpda_drvdata *drvdata,
66 				  struct coresight_device *csdev)
67 {
68 	int rc = -EINVAL;
69 	struct tpdm_drvdata *tpdm_data = dev_get_drvdata(csdev->dev.parent);
70 
71 	if (tpdm_has_dsb_dataset(tpdm_data)) {
72 		rc = fwnode_property_read_u32(dev_fwnode(csdev->dev.parent),
73 				"qcom,dsb-element-bits", &drvdata->dsb_esize);
74 	}
75 	if (tpdm_has_cmb_dataset(tpdm_data)) {
76 		rc = fwnode_property_read_u32(dev_fwnode(csdev->dev.parent),
77 				"qcom,cmb-element-bits", &drvdata->cmb_esize);
78 	}
79 
80 	if (rc)
81 		dev_warn_once(&csdev->dev,
82 			"Failed to read TPDM Element size: %d\n", rc);
83 
84 	return rc;
85 }
86 
87 /*
88  * Search and read element data size from the TPDM node in
89  * the devicetree. Each input port of TPDA is connected to
90  * a TPDM. Different TPDM supports different types of dataset,
91  * and some may support more than one type of dataset.
92  * Parameter "inport" is used to pass in the input port number
93  * of TPDA, and it is set to -1 in the recursize call.
94  */
95 static int tpda_get_element_size(struct tpda_drvdata *drvdata,
96 				 struct coresight_device *csdev,
97 				 int inport)
98 {
99 	int rc = 0;
100 	int i;
101 	struct coresight_device *in;
102 
103 	for (i = 0; i < csdev->pdata->nr_inconns; i++) {
104 		in = csdev->pdata->in_conns[i]->src_dev;
105 		if (!in)
106 			continue;
107 
108 		/* Ignore the paths that do not match port */
109 		if (inport >= 0 &&
110 		    csdev->pdata->in_conns[i]->dest_port != inport)
111 			continue;
112 
113 		if (coresight_device_is_tpdm(in)) {
114 			if (drvdata->dsb_esize || drvdata->cmb_esize)
115 				return -EEXIST;
116 			rc = tpdm_read_element_size(drvdata, in);
117 			if (rc)
118 				return rc;
119 		} else {
120 			/* Recurse down the path */
121 			rc = tpda_get_element_size(drvdata, in, -1);
122 			if (rc)
123 				return rc;
124 		}
125 	}
126 
127 
128 	return rc;
129 }
130 
131 /* Settings pre enabling port control register */
132 static void tpda_enable_pre_port(struct tpda_drvdata *drvdata)
133 {
134 	u32 val;
135 
136 	val = readl_relaxed(drvdata->base + TPDA_CR);
137 	val &= ~TPDA_CR_ATID;
138 	val |= FIELD_PREP(TPDA_CR_ATID, drvdata->atid);
139 	writel_relaxed(val, drvdata->base + TPDA_CR);
140 }
141 
142 static int tpda_enable_port(struct tpda_drvdata *drvdata, int port)
143 {
144 	u32 val;
145 	int rc;
146 
147 	val = readl_relaxed(drvdata->base + TPDA_Pn_CR(port));
148 	tpda_clear_element_size(drvdata->csdev);
149 	rc = tpda_get_element_size(drvdata, drvdata->csdev, port);
150 	if (!rc && (drvdata->dsb_esize || drvdata->cmb_esize)) {
151 		tpda_set_element_size(drvdata, &val);
152 		/* Enable the port */
153 		val |= TPDA_Pn_CR_ENA;
154 		writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
155 	} else if (rc == -EEXIST)
156 		dev_warn_once(&drvdata->csdev->dev,
157 			      "Detected multiple TPDMs on port %d", port);
158 	else
159 		dev_warn_once(&drvdata->csdev->dev,
160 			      "Didn't find TPDM element size");
161 
162 	return rc;
163 }
164 
165 static int __tpda_enable(struct tpda_drvdata *drvdata, int port)
166 {
167 	int ret;
168 
169 	CS_UNLOCK(drvdata->base);
170 
171 	/*
172 	 * Only do pre-port enable for first port that calls enable when the
173 	 * device's main refcount is still 0
174 	 */
175 	lockdep_assert_held(&drvdata->spinlock);
176 	if (!drvdata->csdev->refcnt)
177 		tpda_enable_pre_port(drvdata);
178 
179 	ret = tpda_enable_port(drvdata, port);
180 	CS_LOCK(drvdata->base);
181 
182 	return ret;
183 }
184 
185 static int tpda_enable(struct coresight_device *csdev,
186 		       struct coresight_connection *in,
187 		       struct coresight_connection *out)
188 {
189 	struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
190 	int ret = 0;
191 
192 	spin_lock(&drvdata->spinlock);
193 	if (atomic_read(&in->dest_refcnt) == 0) {
194 		ret = __tpda_enable(drvdata, in->dest_port);
195 		if (!ret) {
196 			atomic_inc(&in->dest_refcnt);
197 			csdev->refcnt++;
198 			dev_dbg(drvdata->dev, "TPDA inport %d enabled.\n", in->dest_port);
199 		}
200 	}
201 
202 	spin_unlock(&drvdata->spinlock);
203 	return ret;
204 }
205 
206 static void __tpda_disable(struct tpda_drvdata *drvdata, int port)
207 {
208 	u32 val;
209 
210 	CS_UNLOCK(drvdata->base);
211 
212 	val = readl_relaxed(drvdata->base + TPDA_Pn_CR(port));
213 	val &= ~TPDA_Pn_CR_ENA;
214 	writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
215 
216 	CS_LOCK(drvdata->base);
217 }
218 
219 static void tpda_disable(struct coresight_device *csdev,
220 			 struct coresight_connection *in,
221 			 struct coresight_connection *out)
222 {
223 	struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
224 
225 	spin_lock(&drvdata->spinlock);
226 	if (atomic_dec_return(&in->dest_refcnt) == 0) {
227 		__tpda_disable(drvdata, in->dest_port);
228 		csdev->refcnt--;
229 	}
230 	spin_unlock(&drvdata->spinlock);
231 
232 	dev_dbg(drvdata->dev, "TPDA inport %d disabled\n", in->dest_port);
233 }
234 
235 static const struct coresight_ops_link tpda_link_ops = {
236 	.enable		= tpda_enable,
237 	.disable	= tpda_disable,
238 };
239 
240 static const struct coresight_ops tpda_cs_ops = {
241 	.link_ops	= &tpda_link_ops,
242 };
243 
244 static int tpda_init_default_data(struct tpda_drvdata *drvdata)
245 {
246 	int atid;
247 	/*
248 	 * TPDA must has a unique atid. This atid can uniquely
249 	 * identify the TPDM trace source connected to the TPDA.
250 	 * The TPDMs which are connected to same TPDA share the
251 	 * same trace-id. When TPDA does packetization, different
252 	 * port will have unique channel number for decoding.
253 	 */
254 	atid = coresight_trace_id_get_system_id();
255 	if (atid < 0)
256 		return atid;
257 
258 	drvdata->atid = atid;
259 	return 0;
260 }
261 
262 static int tpda_probe(struct amba_device *adev, const struct amba_id *id)
263 {
264 	int ret;
265 	struct device *dev = &adev->dev;
266 	struct coresight_platform_data *pdata;
267 	struct tpda_drvdata *drvdata;
268 	struct coresight_desc desc = { 0 };
269 	void __iomem *base;
270 
271 	pdata = coresight_get_platform_data(dev);
272 	if (IS_ERR(pdata))
273 		return PTR_ERR(pdata);
274 	adev->dev.platform_data = pdata;
275 
276 	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
277 	if (!drvdata)
278 		return -ENOMEM;
279 
280 	drvdata->dev = &adev->dev;
281 	dev_set_drvdata(dev, drvdata);
282 
283 	base = devm_ioremap_resource(dev, &adev->res);
284 	if (IS_ERR(base))
285 		return PTR_ERR(base);
286 	drvdata->base = base;
287 
288 	spin_lock_init(&drvdata->spinlock);
289 
290 	ret = tpda_init_default_data(drvdata);
291 	if (ret)
292 		return ret;
293 
294 	desc.name = coresight_alloc_device_name(&tpda_devs, dev);
295 	if (!desc.name)
296 		return -ENOMEM;
297 	desc.type = CORESIGHT_DEV_TYPE_LINK;
298 	desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_MERG;
299 	desc.ops = &tpda_cs_ops;
300 	desc.pdata = adev->dev.platform_data;
301 	desc.dev = &adev->dev;
302 	desc.access = CSDEV_ACCESS_IOMEM(base);
303 	drvdata->csdev = coresight_register(&desc);
304 	if (IS_ERR(drvdata->csdev))
305 		return PTR_ERR(drvdata->csdev);
306 
307 	pm_runtime_put(&adev->dev);
308 
309 	dev_dbg(drvdata->dev, "TPDA initialized\n");
310 	return 0;
311 }
312 
313 static void tpda_remove(struct amba_device *adev)
314 {
315 	struct tpda_drvdata *drvdata = dev_get_drvdata(&adev->dev);
316 
317 	coresight_trace_id_put_system_id(drvdata->atid);
318 	coresight_unregister(drvdata->csdev);
319 }
320 
321 /*
322  * Different TPDA has different periph id.
323  * The difference is 0-7 bits' value. So ignore 0-7 bits.
324  */
325 static struct amba_id tpda_ids[] = {
326 	{
327 		.id     = 0x000f0f00,
328 		.mask   = 0x000fff00,
329 	},
330 	{ 0, 0, NULL },
331 };
332 
333 static struct amba_driver tpda_driver = {
334 	.drv = {
335 		.name   = "coresight-tpda",
336 		.suppress_bind_attrs = true,
337 	},
338 	.probe          = tpda_probe,
339 	.remove		= tpda_remove,
340 	.id_table	= tpda_ids,
341 };
342 
343 module_amba_driver(tpda_driver);
344 
345 MODULE_LICENSE("GPL");
346 MODULE_DESCRIPTION("Trace, Profiling & Diagnostic Aggregator driver");
347