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 */
 44struct 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
 52static 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
 68static 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
 79static 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
 92static 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
102static const struct coresight_ops_link funnel_link_ops = {
103	.enable		= funnel_enable,
104	.disable	= funnel_disable,
105};
106
107static const struct coresight_ops funnel_cs_ops = {
108	.link_ops	= &funnel_link_ops,
109};
110
111static 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
120static 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}
135static DEVICE_ATTR_RW(priority);
136
137static 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
148static 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}
162static DEVICE_ATTR_RO(funnel_ctrl);
163
164static struct attribute *coresight_funnel_attrs[] = {
165	&dev_attr_funnel_ctrl.attr,
166	&dev_attr_priority.attr,
167	NULL,
168};
169ATTRIBUTE_GROUPS(coresight_funnel);
170
171static 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	dev_info(dev, "FUNNEL initialized\n");
225	return 0;
226}
227
228#ifdef CONFIG_PM
229static int funnel_runtime_suspend(struct device *dev)
230{
231	struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
232
233	if (drvdata && !IS_ERR(drvdata->atclk))
234		clk_disable_unprepare(drvdata->atclk);
235
236	return 0;
237}
238
239static int funnel_runtime_resume(struct device *dev)
240{
241	struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
242
243	if (drvdata && !IS_ERR(drvdata->atclk))
244		clk_prepare_enable(drvdata->atclk);
245
246	return 0;
247}
248#endif
249
250static const struct dev_pm_ops funnel_dev_pm_ops = {
251	SET_RUNTIME_PM_OPS(funnel_runtime_suspend, funnel_runtime_resume, NULL)
252};
253
254static struct amba_id funnel_ids[] = {
255	{
256		.id     = 0x0003b908,
257		.mask   = 0x0003ffff,
258	},
259	{ 0, 0},
260};
261
262static struct amba_driver funnel_driver = {
263	.drv = {
264		.name	= "coresight-funnel",
265		.owner	= THIS_MODULE,
266		.pm	= &funnel_dev_pm_ops,
267		.suppress_bind_attrs = true,
268	},
269	.probe		= funnel_probe,
270	.id_table	= funnel_ids,
271};
272builtin_amba_driver(funnel_driver);