[PATCH 04/11 v6] coresight-etb: add CoreSight ETB driver

mathieu.poirier
2014-09-11T15:49:47Z

From: Pratik Patel <pratikp@codeaurora.org>

This driver manages CoreSight ETB (Embedded Trace Buffer) which
acts as a circular buffer sink collecting generated trace data.

Signed-off-by: Pratik Patel <pratikp@codeaurora.org>
Signed-off-by: Panchaxari Prasannamurthy <panchaxari.prasannamurthy@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
drivers/coresight/Makefile | 3 +-
drivers/coresight/coresight-etb10.c | 536 ++++++++++++++++++++++++++++++++++++
2 files changed, 538 insertions(+), 1 deletion(-)
create mode 100644 drivers/coresight/coresight-etb10.c

diff --git a/drivers/coresight/Makefile b/drivers/coresight/Makefile
index 540df99..5dd3d98 100644
--- a/drivers/coresight/Makefile
+++ b/drivers/coresight/Makefile
@@ -3,4 +3,5 @@
#
obj-$(CONFIG_CORESIGHT) += coresight.o
obj-$(CONFIG_OF) += of_coresight.o
-obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-tmc.o coresight-tpiu.o
+obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-tmc.o coresight-tpiu.o \
+ coresight-etb10.o
diff --git a/drivers/coresight/coresight-etb10.c b/drivers/coresight/coresight-etb10.c
new file mode 100644
index 0000000..459e485
--- /dev/null
+++ b/drivers/coresight/coresight-etb10.c
@@ -0,0 +1,536 @@
+/* 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
+
+/**
+ * @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);
+
+ coresight_timeout(drvdata->base, ETB_FFCR, ETB_FFCR_BIT, 0);
+
+ /* disable trace capture */
+ writel_relaxed(0x0, drvdata->base + ETB_CTL_REG);
+
+ coresight_timeout(drvdata->base, ETB_FFSR, ETB_FFSR_BIT, 1);
+ 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 debugfs_status_show(struct seq_file *f, void *ptr)
+{
+ 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 = f->private;
+
+ 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);
+
+ seq_printf(f,
+ "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 0;
+}
+
+static int debugfs_status_show_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, debugfs_status_show, inode->i_private);
+}
+
+static const struct file_operations debugfs_status_ops = {
+ .open = debugfs_status_show_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static const struct coresight_ops_entry debugfs_status_entry = {
+ .name = "status",
+ .mode = S_IRUGO,
+ .ops = &debugfs_status_ops,
+};
+
+static ssize_t debugfs_trigger_cntr_get(void *data, u64 *val)
+{
+ struct etb_drvdata *drvdata = data;
+
+ *val = drvdata->trigger_cntr;
+ return 0;
+}
+
+static ssize_t debugfs_trigger_cntr_set(void *data, u64 val)
+{
+ struct etb_drvdata *drvdata = data;
+
+ drvdata->trigger_cntr = val;
+ return 0;
+}
+CORESIGHT_DEBUGFS_ENTRY(debugfs_trigger_cntr, "trigger_cntr",
+ S_IRUGO | S_IWUSR, debugfs_trigger_cntr_get,
+ debugfs_trigger_cntr_set, "%llx\n");
+
+static const struct coresight_ops_entry *etb_attr_grps[] = {
+ &debugfs_trigger_cntr_entry,
+ &debugfs_status_entry,
+ NULL,
+};
+
+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->debugfs_ops = etb_attr_grps;
+ desc->owner = THIS_MODULE;
+ 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");
--
1.9.1