1 /* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
2  *
3  * Description: CoreSight Funnel driver
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 and
7  * only version 2 as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/types.h>
18 #include <linux/device.h>
19 #include <linux/err.h>
20 #include <linux/fs.h>
21 #include <linux/slab.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/coresight.h>
24 #include <linux/amba/bus.h>
25 #include <linux/clk.h>
26 
27 #include "coresight-priv.h"
28 
29 #define FUNNEL_FUNCTL		0x000
30 #define FUNNEL_PRICTL		0x004
31 
32 #define FUNNEL_HOLDTIME_MASK	0xf00
33 #define FUNNEL_HOLDTIME_SHFT	0x8
34 #define FUNNEL_HOLDTIME		(0x7 << FUNNEL_HOLDTIME_SHFT)
35 
36 /**
37  * struct funnel_drvdata - specifics associated to a funnel component
38  * @base:	memory mapped base address for this component.
39  * @dev:	the device entity associated to this component.
40  * @atclk:	optional clock for the core parts of the funnel.
41  * @csdev:	component vitals needed by the framework.
42  * @priority:	port selection order.
43  */
44 struct funnel_drvdata {
45 	void __iomem		*base;
46 	struct device		*dev;
47 	struct clk		*atclk;
48 	struct coresight_device	*csdev;
49 	unsigned long		priority;
50 };
51 
52 static void funnel_enable_hw(struct funnel_drvdata *drvdata, int port)
53 {
54 	u32 functl;
55 
56 	CS_UNLOCK(drvdata->base);
57 
58 	functl = readl_relaxed(drvdata->base + FUNNEL_FUNCTL);
59 	functl &= ~FUNNEL_HOLDTIME_MASK;
60 	functl |= FUNNEL_HOLDTIME;
61 	functl |= (1 << port);
62 	writel_relaxed(functl, drvdata->base + FUNNEL_FUNCTL);
63 	writel_relaxed(drvdata->priority, drvdata->base + FUNNEL_PRICTL);
64 
65 	CS_LOCK(drvdata->base);
66 }
67 
68 static int funnel_enable(struct coresight_device *csdev, int inport,
69 			 int outport)
70 {
71 	struct funnel_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
72 
73 	funnel_enable_hw(drvdata, inport);
74 
75 	dev_info(drvdata->dev, "FUNNEL inport %d enabled\n", inport);
76 	return 0;
77 }
78 
79 static void funnel_disable_hw(struct funnel_drvdata *drvdata, int inport)
80 {
81 	u32 functl;
82 
83 	CS_UNLOCK(drvdata->base);
84 
85 	functl = readl_relaxed(drvdata->base + FUNNEL_FUNCTL);
86 	functl &= ~(1 << inport);
87 	writel_relaxed(functl, drvdata->base + FUNNEL_FUNCTL);
88 
89 	CS_LOCK(drvdata->base);
90 }
91 
92 static void funnel_disable(struct coresight_device *csdev, int inport,
93 			   int outport)
94 {
95 	struct funnel_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
96 
97 	funnel_disable_hw(drvdata, inport);
98 
99 	dev_info(drvdata->dev, "FUNNEL inport %d disabled\n", inport);
100 }
101 
102 static const struct coresight_ops_link funnel_link_ops = {
103 	.enable		= funnel_enable,
104 	.disable	= funnel_disable,
105 };
106 
107 static const struct coresight_ops funnel_cs_ops = {
108 	.link_ops	= &funnel_link_ops,
109 };
110 
111 static ssize_t priority_show(struct device *dev,
112 			     struct device_attribute *attr, char *buf)
113 {
114 	struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);
115 	unsigned long val = drvdata->priority;
116 
117 	return sprintf(buf, "%#lx\n", val);
118 }
119 
120 static ssize_t priority_store(struct device *dev,
121 			      struct device_attribute *attr,
122 			      const char *buf, size_t size)
123 {
124 	int ret;
125 	unsigned long val;
126 	struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);
127 
128 	ret = kstrtoul(buf, 16, &val);
129 	if (ret)
130 		return ret;
131 
132 	drvdata->priority = val;
133 	return size;
134 }
135 static DEVICE_ATTR_RW(priority);
136 
137 static u32 get_funnel_ctrl_hw(struct funnel_drvdata *drvdata)
138 {
139 	u32 functl;
140 
141 	CS_UNLOCK(drvdata->base);
142 	functl = readl_relaxed(drvdata->base + FUNNEL_FUNCTL);
143 	CS_LOCK(drvdata->base);
144 
145 	return functl;
146 }
147 
148 static ssize_t funnel_ctrl_show(struct device *dev,
149 			     struct device_attribute *attr, char *buf)
150 {
151 	u32 val;
152 	struct funnel_drvdata *drvdata = dev_get_drvdata(dev->parent);
153 
154 	pm_runtime_get_sync(drvdata->dev);
155 
156 	val = get_funnel_ctrl_hw(drvdata);
157 
158 	pm_runtime_put(drvdata->dev);
159 
160 	return sprintf(buf, "%#x\n", val);
161 }
162 static DEVICE_ATTR_RO(funnel_ctrl);
163 
164 static struct attribute *coresight_funnel_attrs[] = {
165 	&dev_attr_funnel_ctrl.attr,
166 	&dev_attr_priority.attr,
167 	NULL,
168 };
169 ATTRIBUTE_GROUPS(coresight_funnel);
170 
171 static int funnel_probe(struct amba_device *adev, const struct amba_id *id)
172 {
173 	int ret;
174 	void __iomem *base;
175 	struct device *dev = &adev->dev;
176 	struct coresight_platform_data *pdata = NULL;
177 	struct funnel_drvdata *drvdata;
178 	struct resource *res = &adev->res;
179 	struct coresight_desc *desc;
180 	struct device_node *np = adev->dev.of_node;
181 
182 	if (np) {
183 		pdata = of_get_coresight_platform_data(dev, np);
184 		if (IS_ERR(pdata))
185 			return PTR_ERR(pdata);
186 		adev->dev.platform_data = pdata;
187 	}
188 
189 	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
190 	if (!drvdata)
191 		return -ENOMEM;
192 
193 	drvdata->dev = &adev->dev;
194 	drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
195 	if (!IS_ERR(drvdata->atclk)) {
196 		ret = clk_prepare_enable(drvdata->atclk);
197 		if (ret)
198 			return ret;
199 	}
200 	dev_set_drvdata(dev, drvdata);
201 
202 	/* Validity for the resource is already checked by the AMBA core */
203 	base = devm_ioremap_resource(dev, res);
204 	if (IS_ERR(base))
205 		return PTR_ERR(base);
206 
207 	drvdata->base = base;
208 	pm_runtime_put(&adev->dev);
209 
210 	desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
211 	if (!desc)
212 		return -ENOMEM;
213 
214 	desc->type = CORESIGHT_DEV_TYPE_LINK;
215 	desc->subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_MERG;
216 	desc->ops = &funnel_cs_ops;
217 	desc->pdata = pdata;
218 	desc->dev = dev;
219 	desc->groups = coresight_funnel_groups;
220 	drvdata->csdev = coresight_register(desc);
221 	if (IS_ERR(drvdata->csdev))
222 		return PTR_ERR(drvdata->csdev);
223 
224 	return 0;
225 }
226 
227 #ifdef CONFIG_PM
228 static int funnel_runtime_suspend(struct device *dev)
229 {
230 	struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
231 
232 	if (drvdata && !IS_ERR(drvdata->atclk))
233 		clk_disable_unprepare(drvdata->atclk);
234 
235 	return 0;
236 }
237 
238 static int funnel_runtime_resume(struct device *dev)
239 {
240 	struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
241 
242 	if (drvdata && !IS_ERR(drvdata->atclk))
243 		clk_prepare_enable(drvdata->atclk);
244 
245 	return 0;
246 }
247 #endif
248 
249 static const struct dev_pm_ops funnel_dev_pm_ops = {
250 	SET_RUNTIME_PM_OPS(funnel_runtime_suspend, funnel_runtime_resume, NULL)
251 };
252 
253 static struct amba_id funnel_ids[] = {
254 	{
255 		.id     = 0x0003b908,
256 		.mask   = 0x0003ffff,
257 	},
258 	{ 0, 0},
259 };
260 
261 static struct amba_driver funnel_driver = {
262 	.drv = {
263 		.name	= "coresight-funnel",
264 		.owner	= THIS_MODULE,
265 		.pm	= &funnel_dev_pm_ops,
266 		.suppress_bind_attrs = true,
267 	},
268 	.probe		= funnel_probe,
269 	.id_table	= funnel_ids,
270 };
271 builtin_amba_driver(funnel_driver);
272