/* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/clk.h>
#include <linux/seq_file.h>
#include <linux/coresight.h>
#include <linux/amba/bus.h>
#include "coresight-priv.h"
#define ETB_RAM_DEPTH_REG 0x004
#define ETB_STATUS_REG 0x00c
#define ETB_RAM_READ_DATA_REG 0x010
#define ETB_RAM_READ_POINTER 0x014
#define ETB_RAM_WRITE_POINTER 0x018
#define ETB_TRG 0x01c
#define ETB_CTL_REG 0x020
#define ETB_RWD_REG 0x024
#define ETB_FFSR 0x300
#define ETB_FFCR 0x304
#define ETB_ITMISCOP0 0xee0
#define ETB_ITTRFLINACK 0xee4
#define ETB_ITTRFLIN 0xee8
#define ETB_ITATBDATA0 0xeeC
#define ETB_ITATBCTR2 0xef0
#define ETB_ITATBCTR1 0xef4
#define ETB_ITATBCTR0 0xef8
/* register description */
/* STS - 0x00C */
#define ETB_STATUS_RAM_FULL BIT(0)
/* CTL - 0x020 */
#define ETB_CTL_CAPT_EN BIT(0)
/* FFCR - 0x304 */
#define ETB_FFCR_EN_FTC BIT(0)
#define ETB_FFCR_FON_MAN BIT(6)
#define ETB_FFCR_STOP_FI BIT(12)
#define ETB_FFCR_STOP_TRIGGER BIT(13)
#define ETB_FFCR_BIT 6
#define ETB_FFSR_BIT 1
#define ETB_FRAME_SIZE_WORDS 4
/**
* struct etb_drvdata - specifics associated to an ETB component
* @base: memory mapped base address for this component.
* @dev: the device entity associated to this component.
* @csdev: component vitals needed by the framework.
* @miscdev: specifics to handle "/dev/xyz.etb" entry.
* @clk: the clock this component is associated to.
* @spinlock: only one at a time pls.
* @in_use: synchronise user space access to etb buffer.
* @buf: area of memory where ETB buffer content gets sent.
* @buffer_depth: size of @buf.
* @enable: this ETB is being used.
* @trigger_cntr: amount of words to store after a trigger.
*/
struct etb_drvdata {
void __iomem *base;
struct device *dev;
struct coresight_device *csdev;
struct miscdevice miscdev;
struct clk *clk;
spinlock_t spinlock;
atomic_t in_use;
u8 *buf;
u32 buffer_depth;
bool enable;
u32 trigger_cntr;
};
static unsigned int etb_get_buffer_depth(struct etb_drvdata *drvdata)
{
int ret;
u32 depth = 0;
ret = clk_prepare_enable(drvdata->clk);
if (ret)
return ret;
/* RO registers don't need locking */
depth = readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
clk_disable_unprepare(drvdata->clk);
return depth;
}
static void etb_enable_hw(struct etb_drvdata *drvdata)
{
int i;
u32 depth;
CS_UNLOCK(drvdata->base);
depth = drvdata->buffer_depth;
/* reset write RAM pointer address */
writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
/* clear entire RAM buffer */
for (i = 0; i < depth; i++)
writel_relaxed(0x0, drvdata->base + ETB_RWD_REG);
/* reset write RAM pointer address */
writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER);
/* reset read RAM pointer address */
writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
writel_relaxed(drvdata->trigger_cntr, drvdata->base + ETB_TRG);
writel_relaxed(ETB_FFCR_EN_FTC | ETB_FFCR_STOP_TRIGGER,
drvdata->base + ETB_FFCR);
/* ETB trace capture enable */
writel_relaxed(ETB_CTL_CAPT_EN, drvdata->base + ETB_CTL_REG);
CS_LOCK(drvdata->base);
}
static int etb_enable(struct coresight_device *csdev)
{
struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
int ret;
unsigned long flags;
ret = clk_prepare_enable(drvdata->clk);
if (ret)
return ret;
spin_lock_irqsave(&drvdata->spinlock, flags);
etb_enable_hw(drvdata);
drvdata->enable = true;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "ETB enabled\n");
return 0;
}
static void etb_disable_hw(struct etb_drvdata *drvdata)
{
u32 ffcr;
CS_UNLOCK(drvdata->base);
ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
/* stop formatter when a stop has completed */
ffcr |= ETB_FFCR_STOP_FI;
writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
/* manually generate a flush of the system */
ffcr |= ETB_FFCR_FON_MAN;
writel_relaxed(ffcr, drvdata->base + ETB_FFCR);
if (coresight_timeout(drvdata->base, ETB_FFCR, ETB_FFCR_BIT, 0)) {
dev_err(drvdata->dev,
"timeout observed when probing at offset %#x\n",
ETB_FFCR);
}
/* disable trace capture */
writel_relaxed(0x0, drvdata->base + ETB_CTL_REG);
if (coresight_timeout(drvdata->base, ETB_FFSR, ETB_FFSR_BIT, 1)) {
dev_err(drvdata->dev,
"timeout observed when probing at offset %#x\n",
ETB_FFCR);
}
CS_LOCK(drvdata->base);
}
static void etb_dump_hw(struct etb_drvdata *drvdata)
{
int i;
u8 *buf_ptr;
u32 read_data, depth;
u32 read_ptr, write_ptr;
u32 frame_off, frame_endoff;
CS_UNLOCK(drvdata->base);
read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
frame_off = write_ptr % ETB_FRAME_SIZE_WORDS;
frame_endoff = ETB_FRAME_SIZE_WORDS - frame_off;
if (frame_off) {
dev_err(drvdata->dev,
"write_ptr: %lu not aligned to formatter frame size\n",
(unsigned long)write_ptr);
dev_err(drvdata->dev, "frameoff: %lu, frame_endoff: %lu\n",
(unsigned long)frame_off, (unsigned long)frame_endoff);
write_ptr += frame_endoff;
}
if ((readl_relaxed(drvdata->base + ETB_STATUS_REG)
& ETB_STATUS_RAM_FULL) == 0)
writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER);
else
writel_relaxed(write_ptr, drvdata->base + ETB_RAM_READ_POINTER);
depth = drvdata->buffer_depth;
buf_ptr = drvdata->buf;
for (i = 0; i < depth; i++) {
read_data = readl_relaxed(drvdata->base +
ETB_RAM_READ_DATA_REG);
*buf_ptr++ = read_data >> 0;
*buf_ptr++ = read_data >> 8;
*buf_ptr++ = read_data >> 16;
*buf_ptr++ = read_data >> 24;
}
if (frame_off) {
buf_ptr -= (frame_endoff * 4);
for (i = 0; i < frame_endoff; i++) {
*buf_ptr++ = 0x0;
*buf_ptr++ = 0x0;
*buf_ptr++ = 0x0;
*buf_ptr++ = 0x0;
}
}
writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER);
CS_LOCK(drvdata->base);
}
static void etb_disable(struct coresight_device *csdev)
{
struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
unsigned long flags;
spin_lock_irqsave(&drvdata->spinlock, flags);
etb_disable_hw(drvdata);
etb_dump_hw(drvdata);
drvdata->enable = false;
spin_unlock_irqrestore(&drvdata->spinlock, flags);
clk_disable_unprepare(drvdata->clk);
dev_info(drvdata->dev, "ETB disabled\n");
}
static const struct coresight_ops_sink etb_sink_ops = {
.enable = etb_enable,
.disable = etb_disable,
};
static const struct coresight_ops etb_cs_ops = {
.sink_ops = &etb_sink_ops,
};
static void etb_dump(struct etb_drvdata *drvdata)
{
unsigned long flags;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->enable) {
etb_disable_hw(drvdata);
etb_dump_hw(drvdata);
etb_enable_hw(drvdata);
}
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "ETB dumped\n");
}
static int etb_open(struct inode *inode, struct file *file)
{
struct etb_drvdata *drvdata = container_of(file->private_data,
struct etb_drvdata, miscdev);
if (atomic_cmpxchg(&drvdata->in_use, 0, 1))
return -EBUSY;
dev_dbg(drvdata->dev, "%s: successfully opened\n", __func__);
return 0;
}
static ssize_t etb_read(struct file *file, char __user *data,
size_t len, loff_t *ppos)
{
u32 depth;
struct etb_drvdata *drvdata = container_of(file->private_data,
struct etb_drvdata, miscdev);
etb_dump(drvdata);
depth = drvdata->buffer_depth;
if (*ppos + len > depth * 4)
len = depth * 4 - *ppos;
if (copy_to_user(data, drvdata->buf + *ppos, len)) {
dev_dbg(drvdata->dev, "%s: copy_to_user failed\n", __func__);
return -EFAULT;
}
*ppos += len;
dev_dbg(drvdata->dev, "%s: %d bytes copied, %d bytes left\n",
__func__, len, (int) (depth * 4 - *ppos));
return len;
}
static int etb_release(struct inode *inode, struct file *file)
{
struct etb_drvdata *drvdata = container_of(file->private_data,
struct etb_drvdata, miscdev);
atomic_set(&drvdata->in_use, 0);
dev_dbg(drvdata->dev, "%s: released\n", __func__);
return 0;
}
static const struct file_operations etb_fops = {
.owner = THIS_MODULE,
.open = etb_open,
.read = etb_read,
.release = etb_release,
.llseek = no_llseek,
};
static ssize_t status_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int ret;
unsigned long flags;
u32 etb_rdr, etb_sr, etb_rrp, etb_rwp;
u32 etb_trg, etb_cr, etb_ffsr, etb_ffcr;
struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
ret = clk_prepare_enable(drvdata->clk);
if (ret)
goto out;
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->base);
etb_rdr = readl_relaxed(drvdata->base + ETB_RAM_DEPTH_REG);
etb_sr = readl_relaxed(drvdata->base + ETB_STATUS_REG);
etb_rrp = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER);
etb_rwp = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER);
etb_trg = readl_relaxed(drvdata->base + ETB_TRG);
etb_cr = readl_relaxed(drvdata->base + ETB_CTL_REG);
etb_ffsr = readl_relaxed(drvdata->base + ETB_FFSR);
etb_ffcr = readl_relaxed(drvdata->base + ETB_FFCR);
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
clk_disable_unprepare(drvdata->clk);
return sprintf(buf,
"Depth:\t\t0x%x\n"
"Status:\t\t0x%x\n"
"RAM read ptr:\t0x%x\n"
"RAM wrt ptr:\t0x%x\n"
"Trigger cnt:\t0x%x\n"
"Control:\t0x%x\n"
"Flush status:\t0x%x\n"
"Flush ctrl:\t0x%x\n",
etb_rdr, etb_sr, etb_rrp, etb_rwp,
etb_trg, etb_cr, etb_ffsr, etb_ffcr);
out:
return -EINVAL;
}
static DEVICE_ATTR_RO(status);
static ssize_t trigger_cntr_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
unsigned long val = drvdata->trigger_cntr;
return sprintf(buf, "%#lx\n", val);
}
static ssize_t trigger_cntr_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
int ret;
unsigned long val;
struct etb_drvdata *drvdata = dev_get_drvdata(dev->parent);
ret = kstrtoul(buf, 16, &val);
if (ret)
return ret;
drvdata->trigger_cntr = val;
return size;
}
static DEVICE_ATTR_RW(trigger_cntr);
static struct attribute *coresight_etb_attrs[] = {
&dev_attr_trigger_cntr.attr,
&dev_attr_status.attr,
NULL,
};
ATTRIBUTE_GROUPS(coresight_etb);
static int etb_probe(struct amba_device *adev, const struct amba_id *id)
{
int ret;
void __iomem *base;
struct device *dev = &adev->dev;
struct coresight_platform_data *pdata = NULL;
struct etb_drvdata *drvdata;
struct resource *res = &adev->res;
struct coresight_desc *desc;
struct device_node *np = adev->dev.of_node;
if (np) {
pdata = of_get_coresight_platform_data(dev, np);
if (IS_ERR(pdata))
return PTR_ERR(pdata);
adev->dev.platform_data = pdata;
}
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
drvdata->dev = &adev->dev;
dev_set_drvdata(dev, drvdata);
/* validity for the resource is already checked by the AMBA core */
base = devm_ioremap_resource(dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
drvdata->base = base;
spin_lock_init(&drvdata->spinlock);
drvdata->clk = adev->pclk;
ret = clk_prepare_enable(drvdata->clk);
if (ret)
return ret;
drvdata->buffer_depth = etb_get_buffer_depth(drvdata);
clk_disable_unprepare(drvdata->clk);
if (drvdata->buffer_depth < 0)
return -EINVAL;
drvdata->buf = devm_kzalloc(dev,
drvdata->buffer_depth * 4, GFP_KERNEL);
if (!drvdata->buf)
return -ENOMEM;
desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
if (!desc)
return -ENOMEM;
desc->type = CORESIGHT_DEV_TYPE_SINK;
desc->subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
desc->ops = &etb_cs_ops;
desc->pdata = pdata;
desc->dev = dev;
desc->groups = coresight_etb_groups;
drvdata->csdev = coresight_register(desc);
if (IS_ERR(drvdata->csdev))
return PTR_ERR(drvdata->csdev);
drvdata->miscdev.name = pdata->name;
drvdata->miscdev.minor = MISC_DYNAMIC_MINOR;
drvdata->miscdev.fops = &etb_fops;
ret = misc_register(&drvdata->miscdev);
if (ret)
goto err_misc_register;
dev_info(dev, "ETB initialized\n");
return 0;
err_misc_register:
coresight_unregister(drvdata->csdev);
return ret;
}
static int etb_remove(struct amba_device *adev)
{
struct etb_drvdata *drvdata = amba_get_drvdata(adev);
misc_deregister(&drvdata->miscdev);
coresight_unregister(drvdata->csdev);
return 0;
}
static struct amba_id etb_ids[] = {
{
.id = 0x0003b907,
.mask = 0x0003ffff,
},
{ 0, 0},
};
static struct amba_driver etb_driver = {
.drv = {
.name = "coresight-etb10",
.owner = THIS_MODULE,
},
.probe = etb_probe,
.remove = etb_remove,
.id_table = etb_ids,
};
static int __init etb_init(void)
{
return amba_driver_register(&etb_driver);
}
module_init(etb_init);
static void __exit etb_exit(void)
{
amba_driver_unregister(&etb_driver);
}
module_exit(etb_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("CoreSight Embedded Trace Buffer driver");
