blob: 58e8588013842a5976cfc079cc93220b2527c25e [file] [log] [blame]
/* Copyright (c) 2010-2011, 2013, 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/debugfs.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <asm/uaccess.h>
#include <mach/msm_iomap.h>
#include "rpm_log.h"
/* registers in MSM_RPM_LOG_PAGE_INDICES */
enum {
MSM_RPM_LOG_TAIL,
MSM_RPM_LOG_HEAD
};
/* used to 4 byte align message lengths */
#define PADDED_LENGTH(x) (0xFFFFFFFC & ((x) + 3))
/* calculates the character string length of a message of byte length x */
#define PRINTED_LENGTH(x) ((x) * 6 + 3)
/* number of ms to wait between checking for new messages in the RPM log */
#define RECHECK_TIME (50)
#define VERSION_8974 0x1000
#define RPM_ULOG_LENGTH_SHIFT 16
#define RPM_ULOG_LENGTH_MASK 0xFFFF0000
struct msm_rpm_log_buffer {
char *data;
u32 len;
u32 pos;
u32 max_len;
u32 read_idx;
struct msm_rpm_log_platform_data *pdata;
};
/******************************************************************************
* Internal functions
*****************************************************************************/
static inline u32
msm_rpm_log_read(const struct msm_rpm_log_platform_data *pdata, u32 page,
u32 reg)
{
return readl_relaxed(pdata->reg_base + pdata->reg_offsets[page]
+ reg * 4);
}
/*
* msm_rpm_log_copy() - Copies messages from a volatile circular buffer in
* the RPM's shared memory into a private local buffer
* msg_buffer: pointer to local buffer (string)
* buf_len: length of local buffer in bytes
* read_start_idx: index into shared memory buffer
*
* Return value: number of bytes written to the local buffer
*
* Copies messages stored in a circular buffer in the RPM Message Memory into
* a specified local buffer. The RPM processor is unaware of these reading
* efforts, so care is taken to make sure that messages are valid both before
* and after reading. The RPM processor utilizes a ULog driver to write the
* log. The RPM processor maintains tail and head indices. These correspond
* to the next byte to write into, and the first valid byte, respectively.
* Both indices increase monotonically (except for rollover).
*
* Messages take the form of [(u32)length] [(char)data0,1,...] in which the
* length specifies the number of payload bytes. Messages must be 4 byte
* aligned, so padding is added at the end of a message as needed.
*
* Print format:
* - 0xXX, 0xXX, 0xXX
* - 0xXX
* etc...
*/
static u32 msm_rpm_log_copy(const struct msm_rpm_log_platform_data *pdata,
char *msg_buffer, u32 buf_len, u32 *read_idx)
{
u32 head_idx, tail_idx;
u32 pos = 0;
u32 i = 0;
u32 msg_len;
u32 pos_start;
char temp[4];
tail_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_TAIL);
head_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_HEAD);
/* loop while the remote buffer has valid messages left to read */
while (tail_idx - head_idx > 0 && tail_idx - *read_idx > 0) {
head_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_HEAD);
tail_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_TAIL);
/* check if the message to be read is valid */
if (tail_idx - *read_idx > tail_idx - head_idx) {
*read_idx = head_idx;
continue;
}
/*
* Ensure that all indices are 4 byte aligned.
* This conditions is required to interact with a ULog buffer
* properly.
*/
if (!IS_ALIGNED((tail_idx | head_idx | *read_idx), 4))
break;
msg_len = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_BUFFER,
((*read_idx) & pdata->log_len_mask) >> 2);
/* Message length for 8974 is first 2 bytes.
* Exclude message length and format from message length.
*/
if (pdata->version == VERSION_8974) {
msg_len = (msg_len & RPM_ULOG_LENGTH_MASK) >>
RPM_ULOG_LENGTH_SHIFT;
msg_len -= 4;
}
/* handle messages that claim to be longer than the log */
if (PADDED_LENGTH(msg_len) > tail_idx - *read_idx - 4)
msg_len = tail_idx - *read_idx - 4;
/* check that the local buffer has enough space for this msg */
if (pos + PRINTED_LENGTH(msg_len) > buf_len)
break;
pos_start = pos;
pos += scnprintf(msg_buffer + pos, buf_len - pos, "- ");
/* copy message payload to local buffer */
for (i = 0; i < msg_len; i++) {
/* read from shared memory 4 bytes at a time */
if (IS_ALIGNED(i, 4))
*((u32 *)temp) = msm_rpm_log_read(pdata,
MSM_RPM_LOG_PAGE_BUFFER,
((*read_idx + 4 + i) &
pdata->log_len_mask) >> 2);
pos += scnprintf(msg_buffer + pos, buf_len - pos,
"0x%02X, ", temp[i & 0x03]);
}
pos += scnprintf(msg_buffer + pos, buf_len - pos, "\n");
head_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_HEAD);
tail_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_TAIL);
/* roll back if message that was read is not still valid */
if (tail_idx - *read_idx > tail_idx - head_idx)
pos = pos_start;
*read_idx += PADDED_LENGTH(msg_len) + 4;
}
return pos;
}
/*
* msm_rpm_log_file_read() - Reads in log buffer messages then outputs them to a
* user buffer
*
* Return value:
* 0: success
* -ENOMEM: no memory available
* -EINVAL: user buffer null or requested bytes 0
* -EFAULT: user buffer not writeable
* -EAGAIN: no bytes available at the moment
*/
static ssize_t msm_rpm_log_file_read(struct file *file, char __user *bufu,
size_t count, loff_t *ppos)
{
u32 out_len, remaining;
struct msm_rpm_log_platform_data *pdata;
struct msm_rpm_log_buffer *buf;
buf = file->private_data;
if (!buf)
return -ENOMEM;
pdata = buf->pdata;
if (!pdata)
return -EINVAL;
if (!buf->data)
return -ENOMEM;
if (!bufu || count == 0)
return -EINVAL;
if (!access_ok(VERIFY_WRITE, bufu, count))
return -EFAULT;
/* check for more messages if local buffer empty */
if (buf->pos == buf->len) {
buf->pos = 0;
buf->len = msm_rpm_log_copy(pdata, buf->data, buf->max_len,
&(buf->read_idx));
}
if ((file->f_flags & O_NONBLOCK) && buf->len == 0)
return -EAGAIN;
/* loop until new messages arrive */
while (buf->len == 0) {
cond_resched();
if (msleep_interruptible(RECHECK_TIME))
break;
buf->len = msm_rpm_log_copy(pdata, buf->data, buf->max_len,
&(buf->read_idx));
}
out_len = ((buf->len - buf->pos) < count ? buf->len - buf->pos : count);
remaining = __copy_to_user(bufu, &(buf->data[buf->pos]), out_len);
buf->pos += out_len - remaining;
return out_len - remaining;
}
/*
* msm_rpm_log_file_open() - Allows a new reader to open the RPM log virtual
* file
*
* One local buffer is kmalloc'ed for each reader, so no resource sharing has
* to take place (besides the read only access to the RPM log buffer).
*
* Return value:
* 0: success
* -ENOMEM: no memory available
*/
static int msm_rpm_log_file_open(struct inode *inode, struct file *file)
{
struct msm_rpm_log_buffer *buf;
struct msm_rpm_log_platform_data *pdata;
pdata = inode->i_private;
if (!pdata)
return -EINVAL;
file->private_data =
kmalloc(sizeof(struct msm_rpm_log_buffer), GFP_KERNEL);
if (!file->private_data) {
pr_err("%s: ERROR kmalloc failed to allocate %d bytes\n",
__func__, sizeof(struct msm_rpm_log_buffer));
return -ENOMEM;
}
buf = file->private_data;
buf->data = kmalloc(PRINTED_LENGTH(pdata->log_len), GFP_KERNEL);
if (!buf->data) {
kfree(file->private_data);
file->private_data = NULL;
pr_err("%s: ERROR kmalloc failed to allocate %d bytes\n",
__func__, PRINTED_LENGTH(pdata->log_len));
return -ENOMEM;
}
buf->pdata = pdata;
buf->len = 0;
buf->pos = 0;
buf->max_len = PRINTED_LENGTH(pdata->log_len);
buf->read_idx = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_INDICES,
MSM_RPM_LOG_HEAD);
return 0;
}
static int msm_rpm_log_file_close(struct inode *inode, struct file *file)
{
kfree(((struct msm_rpm_log_buffer *)file->private_data)->data);
kfree(file->private_data);
return 0;
}
static const struct file_operations msm_rpm_log_file_fops = {
.owner = THIS_MODULE,
.open = msm_rpm_log_file_open,
.read = msm_rpm_log_file_read,
.release = msm_rpm_log_file_close,
};
static int __devinit msm_rpm_log_probe(struct platform_device *pdev)
{
struct dentry *dent;
struct msm_rpm_log_platform_data *pdata;
struct resource *res = NULL;
struct device_node *node = NULL;
phys_addr_t page_buffer_address, rpm_addr_phys;
int ret = 0;
char *key = NULL;
uint32_t val = 0;
node = pdev->dev.of_node;
if (node) {
pdata = kzalloc(sizeof(struct msm_rpm_log_platform_data),
GFP_KERNEL);
if (!pdata)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
kfree(pdata);
return -EINVAL;
}
pdata->phys_addr_base = res->start;
pdata->phys_size = resource_size(res);
pdata->reg_base = ioremap_nocache(pdata->phys_addr_base,
pdata->phys_size);
if (!pdata->reg_base) {
pr_err("%s: ERROR could not ioremap: start=%p, len=%u\n",
__func__, (void *) pdata->phys_addr_base,
pdata->phys_size);
kfree(pdata);
return -EBUSY;
}
/* Read various parameters from the header if the
* version of the RPM Ulog is 0x1000. This version
* corresponds to the node in the rpm header which
* holds RPM log on 8974.
*
* offset-page-buffer-addr: At this offset header
* contains address of the location where raw log
* starts
* offset-log-len: At this offset header contains
* the length of the log buffer.
* offset-log-len-mask: At this offset header contains
* the log length mask for the buffer.
* offset-page-indices: At this offset header contains
* the index for writer. */
key = "qcom,offset-version";
ret = of_property_read_u32(node, key, &val);
if (ret) {
pr_err("%s: Error in name %s key %s\n",
__func__, node->full_name, key);
ret = -EFAULT;
goto fail;
}
pdata->version = readl_relaxed(pdata->reg_base + val);
if (pdata->version == VERSION_8974) {
key = "qcom,rpm-addr-phys";
ret = of_property_read_u32(node, key, &val);
if (ret) {
pr_err("%s: Error in name %s key %s\n",
__func__, node->full_name, key);
ret = -EFAULT;
goto fail;
}
rpm_addr_phys = val;
key = "qcom,offset-page-buffer-addr";
ret = of_property_read_u32(node, key, &val);
if (ret) {
pr_err("%s: Error in name %s key %s\n",
__func__, node->full_name, key);
ret = -EFAULT;
goto fail;
}
page_buffer_address = rpm_addr_phys +
readl_relaxed(pdata->reg_base + val);
pdata->reg_offsets[MSM_RPM_LOG_PAGE_BUFFER] =
page_buffer_address - pdata->phys_addr_base;
key = "qcom,offset-log-len";
ret = of_property_read_u32(node, key, &val);
if (ret) {
pr_err("%s: Error in name %s key %s\n",
__func__, node->full_name, key);
ret = -EFAULT;
goto fail;
}
pdata->log_len = readl_relaxed(pdata->reg_base + val);
if (pdata->log_len > pdata->phys_size) {
pr_err("%s: Error phy size: %d should be atleast log length: %d\n",
__func__, pdata->phys_size,
pdata->log_len);
ret = -EINVAL;
goto fail;
}
key = "qcom,offset-log-len-mask";
ret = of_property_read_u32(node, key, &val);
if (ret) {
pr_err("%s: Error in name %s key %s\n",
__func__, node->full_name, key);
ret = -EFAULT;
goto fail;
}
pdata->log_len_mask = readl_relaxed(pdata->reg_base
+ val);
key = "qcom,offset-page-indices";
ret = of_property_read_u32(node, key, &val);
if (ret) {
pr_err("%s: Error in name %s key %s\n",
__func__, node->full_name, key);
ret = -EFAULT;
goto fail;
}
pdata->reg_offsets[MSM_RPM_LOG_PAGE_INDICES] =
val;
} else{
ret = -EINVAL;
goto fail;
}
} else{
pdata = pdev->dev.platform_data;
if (!pdata)
return -EINVAL;
pdata->reg_base = ioremap(pdata->phys_addr_base,
pdata->phys_size);
if (!pdata->reg_base) {
pr_err("%s: ERROR could not ioremap: start=%p, len=%u\n",
__func__, (void *) pdata->phys_addr_base,
pdata->phys_size);
return -EBUSY;
}
}
dent = debugfs_create_file("rpm_log", S_IRUGO, NULL,
pdata, &msm_rpm_log_file_fops);
if (!dent) {
pr_err("%s: ERROR debugfs_create_file failed\n", __func__);
if (pdata->version == VERSION_8974) {
ret = -ENOMEM;
goto fail;
}
return -ENOMEM;
}
platform_set_drvdata(pdev, dent);
pr_notice("%s: OK\n", __func__);
return 0;
fail:
iounmap(pdata->reg_base);
kfree(pdata);
return ret;
}
static int __devexit msm_rpm_log_remove(struct platform_device *pdev)
{
struct dentry *dent;
struct msm_rpm_log_platform_data *pdata;
pdata = pdev->dev.platform_data;
iounmap(pdata->reg_base);
dent = platform_get_drvdata(pdev);
debugfs_remove(dent);
platform_set_drvdata(pdev, NULL);
pr_notice("%s: OK\n", __func__);
return 0;
}
static struct of_device_id rpm_log_table[] = {
{.compatible = "qcom,rpm-log"},
{},
};
static struct platform_driver msm_rpm_log_driver = {
.probe = msm_rpm_log_probe,
.remove = __devexit_p(msm_rpm_log_remove),
.driver = {
.name = "msm_rpm_log",
.owner = THIS_MODULE,
.of_match_table = rpm_log_table,
},
};
static int __init msm_rpm_log_init(void)
{
return platform_driver_register(&msm_rpm_log_driver);
}
static void __exit msm_rpm_log_exit(void)
{
platform_driver_unregister(&msm_rpm_log_driver);
}
module_init(msm_rpm_log_init);
module_exit(msm_rpm_log_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("MSM RPM Log driver");
MODULE_VERSION("1.0");
MODULE_ALIAS("platform:msm_rpm_log");