| /* Copyright (c) 2010-2011, Code Aurora Forum. 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/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) |
| |
| 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); |
| /* 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 the reported buffer size is within limits of |
| * known maximum size and that all indices are 4 byte aligned. |
| * These conditions are required to interact with a ULog buffer |
| * properly. |
| */ |
| if (tail_idx - head_idx > pdata->log_len || |
| !IS_ALIGNED((tail_idx | head_idx | *read_idx), 4)) |
| break; |
| |
| msg_len = msm_rpm_log_read(pdata, MSM_RPM_LOG_PAGE_BUFFER, |
| (*read_idx >> 2) & pdata->log_len_mask); |
| |
| /* 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) >> 2) & |
| pdata->log_len_mask); |
| |
| 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); |
| |
| /* 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; |
| pdata = buf->pdata; |
| if (!pdata) |
| return -EINVAL; |
| if (!buf) |
| return -ENOMEM; |
| 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; |
| |
| 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, |
| pdev->dev.platform_data, &msm_rpm_log_file_fops); |
| if (!dent) { |
| pr_err("%s: ERROR debugfs_create_file failed\n", __func__); |
| return -ENOMEM; |
| } |
| |
| platform_set_drvdata(pdev, dent); |
| |
| pr_notice("%s: OK\n", __func__); |
| return 0; |
| } |
| |
| 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 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, |
| }, |
| }; |
| |
| 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"); |