[PATCH] msm: smd: Add smd_pkt driver
Niranjana Vishwanathapura
nvishwan at codeaurora.org
Wed Dec 15 13:27:55 EST 2010
Add smd_pkt driver which provides device interface
to smd packet ports.
Signed-off-by: Niranjana Vishwanathapura <nvishwan at codeaurora.org>
---
drivers/char/Kconfig | 8 +
drivers/char/Makefile | 2 +
drivers/char/msm_smd_pkt.c | 466 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 476 insertions(+), 0 deletions(-)
create mode 100644 drivers/char/msm_smd_pkt.c
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 43d3395..f82af94 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -1144,5 +1144,13 @@ config RAMOOPS
This enables panic and oops messages to be logged to a circular
buffer in RAM where it can be read back at some later point.
+config MSM_SMD_PKT
+ bool "Enable device interface for some SMD packet ports"
+ default n
+ depends on MSM_SMD
+ help
+ Enables userspace clients to read and write to some packet SMD
+ ports via device interface for MSM chipset.
+
endmenu
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index ba53ec9..1c4413f 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -98,3 +98,5 @@ obj-$(CONFIG_RAMOOPS) += ramoops.o
obj-$(CONFIG_JS_RTC) += js-rtc.o
js-rtc-y = rtc.o
+
+obj-$(CONFIG_MSM_SMD_PKT) += msm_smd_pkt.o
diff --git a/drivers/char/msm_smd_pkt.c b/drivers/char/msm_smd_pkt.c
new file mode 100644
index 0000000..b6f8a65
--- /dev/null
+++ b/drivers/char/msm_smd_pkt.c
@@ -0,0 +1,466 @@
+/* Copyright (c) 2008-2010, 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ */
+/*
+ * SMD Packet Driver -- Provides userspace interface to SMD packet ports.
+ */
+
+#include <linux/slab.h>
+#include <linux/cdev.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/sched.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/workqueue.h>
+#include <linux/poll.h>
+
+#include <mach/msm_smd.h>
+
+#define NUM_SMD_PKT_PORTS 9
+#define DEVICE_NAME "smdpkt"
+#define MAX_BUF_SIZE 2048
+
+struct smd_pkt_dev {
+ struct cdev cdev;
+ struct device *devicep;
+
+ struct smd_channel *ch;
+ int open_count;
+ struct mutex ch_lock;
+ struct mutex rx_lock;
+ struct mutex tx_lock;
+ wait_queue_head_t ch_read_wait_queue;
+ wait_queue_head_t ch_opened_wait_queue;
+
+ int i;
+
+ unsigned char tx_buf[MAX_BUF_SIZE];
+ unsigned char rx_buf[MAX_BUF_SIZE];
+ int remote_open;
+
+} *smd_pkt_devp[NUM_SMD_PKT_PORTS];
+
+struct class *smd_pkt_classp;
+static dev_t smd_pkt_number;
+
+static int msm_smd_pkt_debug_enable;
+module_param_named(debug_enable, msm_smd_pkt_debug_enable,
+ int, S_IRUGO | S_IWUSR | S_IWGRP);
+
+#ifdef DEBUG
+#define D_DUMP_BUFFER(prestr, cnt, buf) do { \
+ int i; \
+ if (msm_smd_pkt_debug_enable) { \
+ pr_debug("%s", prestr); \
+ for (i = 0; i < cnt; i++) \
+ pr_debug("%.2x", buf[i]); \
+ pr_debug("\n"); \
+ } \
+ } while (0)
+#else
+#define D_DUMP_BUFFER(prestr, cnt, buf) do {} while (0)
+#endif
+
+#ifdef DEBUG
+#define DBG(x...) do { \
+ if (msm_smd_pkt_debug_enable) \
+ pr_debug(x); \
+ } while (0)
+#else
+#define DBG(x...) do {} while (0)
+#endif
+
+static void check_and_wakeup_reader(struct smd_pkt_dev *smd_pkt_devp)
+{
+ int sz;
+
+ if (!smd_pkt_devp || !smd_pkt_devp->ch)
+ return;
+
+ sz = smd_cur_packet_size(smd_pkt_devp->ch);
+ if (sz == 0) {
+ DBG("no packet\n");
+ return;
+ }
+ if (sz > smd_read_avail(smd_pkt_devp->ch)) {
+ DBG("incomplete packet\n");
+ return;
+ }
+
+ DBG("waking up reader\n");
+ wake_up_interruptible(&smd_pkt_devp->ch_read_wait_queue);
+}
+
+static int smd_pkt_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int r, bytes_read;
+ struct smd_pkt_dev *smd_pkt_devp;
+ struct smd_channel *chl;
+
+ DBG("read %d bytes\n", count);
+ if (count > MAX_BUF_SIZE)
+ return -EINVAL;
+
+ smd_pkt_devp = file->private_data;
+ if (!smd_pkt_devp || !smd_pkt_devp->ch)
+ return -EINVAL;
+
+ chl = smd_pkt_devp->ch;
+wait_for_packet:
+ r = wait_event_interruptible(smd_pkt_devp->ch_read_wait_queue,
+ (smd_cur_packet_size(chl) > 0 &&
+ smd_read_avail(chl) >=
+ smd_cur_packet_size(chl)));
+
+ if (r < 0) {
+ if (r != -ERESTARTSYS)
+ pr_err("wait returned %d\n", r);
+ return r;
+ }
+
+ mutex_lock(&smd_pkt_devp->rx_lock);
+
+ bytes_read = smd_cur_packet_size(smd_pkt_devp->ch);
+ if (bytes_read == 0 ||
+ bytes_read < smd_read_avail(smd_pkt_devp->ch)) {
+ mutex_unlock(&smd_pkt_devp->rx_lock);
+ DBG("Nothing to read\n");
+ goto wait_for_packet;
+ }
+
+ if (bytes_read > count) {
+ mutex_unlock(&smd_pkt_devp->rx_lock);
+ pr_info("packet size %d > buffer size %d", bytes_read, count);
+ return -EINVAL;
+ }
+
+ r = smd_read(smd_pkt_devp->ch, smd_pkt_devp->rx_buf, bytes_read);
+ if (r != bytes_read) {
+ mutex_unlock(&smd_pkt_devp->rx_lock);
+ pr_err("smd_read failed to read %d bytes: %d\n", bytes_read, r);
+ return -EIO;
+ }
+
+ D_DUMP_BUFFER("read: ", bytes_read, smd_pkt_devp->rx_buf);
+ r = copy_to_user(buf, smd_pkt_devp->rx_buf, bytes_read);
+ mutex_unlock(&smd_pkt_devp->rx_lock);
+ if (r) {
+ pr_err("copy_to_user failed %d\n", r);
+ return -EFAULT;
+ }
+
+ DBG("read complete %d bytes\n", bytes_read);
+ check_and_wakeup_reader(smd_pkt_devp);
+
+ return bytes_read;
+}
+
+static int smd_pkt_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int r;
+ struct smd_pkt_dev *smd_pkt_devp;
+
+ if (count > MAX_BUF_SIZE)
+ return -EINVAL;
+
+ DBG("writting %d bytes\n", count);
+
+ smd_pkt_devp = file->private_data;
+ if (!smd_pkt_devp || !smd_pkt_devp->ch)
+ return -EINVAL;
+
+ mutex_lock(&smd_pkt_devp->tx_lock);
+ if (smd_write_avail(smd_pkt_devp->ch) < count) {
+ mutex_unlock(&smd_pkt_devp->tx_lock);
+ DBG("Not enough space to write\n");
+ return -ENOMEM;
+ }
+
+ D_DUMP_BUFFER("write: ", count, buf);
+ r = copy_from_user(smd_pkt_devp->tx_buf, buf, count);
+ if (r) {
+ mutex_unlock(&smd_pkt_devp->tx_lock);
+ pr_err("copy_from_user failed %d\n", r);
+ return -EFAULT;
+ }
+
+ r = smd_write(smd_pkt_devp->ch, smd_pkt_devp->tx_buf, count);
+ if (r != count) {
+ mutex_unlock(&smd_pkt_devp->tx_lock);
+ pr_err("smd_write failed to write %d bytes: %d.\n", count, r);
+ return -EIO;
+ }
+ mutex_unlock(&smd_pkt_devp->tx_lock);
+
+ DBG("wrote %d bytes\n", count);
+ return count;
+}
+
+static unsigned int smd_pkt_poll(struct file *file, poll_table *wait)
+{
+ struct smd_pkt_dev *smd_pkt_devp;
+ unsigned int mask = 0;
+
+ smd_pkt_devp = file->private_data;
+ if (!smd_pkt_devp)
+ return POLLERR;
+
+ DBG("poll waiting\n");
+ poll_wait(file, &smd_pkt_devp->ch_read_wait_queue, wait);
+ if (smd_read_avail(smd_pkt_devp->ch))
+ mask |= POLLIN | POLLRDNORM;
+
+ DBG("poll return\n");
+ return mask;
+}
+
+static void smd_pkt_ch_notify(void *priv, unsigned event)
+{
+ struct smd_pkt_dev *smd_pkt_devp = priv;
+
+ if (smd_pkt_devp->ch == 0)
+ return;
+
+ switch (event) {
+ case SMD_EVENT_DATA:
+ DBG("data\n");
+ check_and_wakeup_reader(smd_pkt_devp);
+ break;
+
+ case SMD_EVENT_OPEN:
+ DBG("remote open\n");
+ smd_pkt_devp->remote_open = 1;
+ wake_up_interruptible(&smd_pkt_devp->ch_opened_wait_queue);
+ break;
+
+ case SMD_EVENT_CLOSE:
+ smd_pkt_devp->remote_open = 0;
+ pr_info("remote closed\n");
+ break;
+
+ default:
+ pr_err("unknown event %d\n", event);
+ break;
+ }
+}
+
+static char *smd_pkt_dev_name[] = {
+ "smdcntl0",
+ "smdcntl1",
+ "smdcntl2",
+ "smdcntl3",
+ "smdcntl4",
+ "smdcntl5",
+ "smdcntl6",
+ "smdcntl7",
+ "smd22",
+};
+
+static char *smd_ch_name[] = {
+ "DATA5_CNTL",
+ "DATA6_CNTL",
+ "DATA7_CNTL",
+ "DATA8_CNTL",
+ "DATA9_CNTL",
+ "DATA12_CNTL",
+ "DATA13_CNTL",
+ "DATA14_CNTL",
+ "DATA22",
+};
+
+static int smd_pkt_open(struct inode *inode, struct file *file)
+{
+ int r = 0;
+ struct smd_pkt_dev *smd_pkt_devp;
+
+ smd_pkt_devp = container_of(inode->i_cdev, struct smd_pkt_dev, cdev);
+ if (!smd_pkt_devp)
+ return -EINVAL;
+
+ file->private_data = smd_pkt_devp;
+
+ mutex_lock(&smd_pkt_devp->ch_lock);
+ if (smd_pkt_devp->open_count == 0) {
+ r = smd_open(smd_ch_name[smd_pkt_devp->i],
+ &smd_pkt_devp->ch, smd_pkt_devp,
+ smd_pkt_ch_notify);
+ if (r < 0) {
+ pr_err("smd_open failed for %s, %d\n",
+ smd_ch_name[smd_pkt_devp->i], r);
+ goto out;
+ }
+
+ r = wait_event_interruptible_timeout(
+ smd_pkt_devp->ch_opened_wait_queue,
+ smd_pkt_devp->remote_open,
+ msecs_to_jiffies(2 * HZ));
+ if (r == 0)
+ r = -ETIMEDOUT;
+
+ if (r < 0) {
+ pr_err("wait returned %d\n", r);
+ smd_close(smd_pkt_devp->ch);
+ smd_pkt_devp->ch = 0;
+ } else {
+ smd_pkt_devp->open_count++;
+ r = 0;
+ }
+ }
+out:
+ mutex_unlock(&smd_pkt_devp->ch_lock);
+ return r;
+}
+
+static int smd_pkt_release(struct inode *inode, struct file *file)
+{
+ int r = 0;
+ struct smd_pkt_dev *smd_pkt_devp = file->private_data;
+
+ if (!smd_pkt_devp)
+ return -EINVAL;
+
+ mutex_lock(&smd_pkt_devp->ch_lock);
+ if (--smd_pkt_devp->open_count == 0) {
+ r = smd_close(smd_pkt_devp->ch);
+ smd_pkt_devp->ch = 0;
+ }
+ mutex_unlock(&smd_pkt_devp->ch_lock);
+
+ return r;
+}
+
+static const struct file_operations smd_pkt_fops = {
+ .owner = THIS_MODULE,
+ .open = smd_pkt_open,
+ .release = smd_pkt_release,
+ .read = smd_pkt_read,
+ .write = smd_pkt_write,
+ .poll = smd_pkt_poll,
+};
+
+static int __init smd_pkt_init(void)
+{
+ int i;
+ int r;
+
+ r = alloc_chrdev_region(&smd_pkt_number, 0,
+ NUM_SMD_PKT_PORTS, DEVICE_NAME);
+ if (r) {
+ pr_err("alloc_chrdev_region() failed %d\n", r);
+ return r;
+ }
+
+ smd_pkt_classp = class_create(THIS_MODULE, DEVICE_NAME);
+ if (IS_ERR(smd_pkt_classp)) {
+ r = PTR_ERR(smd_pkt_classp);
+ pr_err("class_create() failed %d\n", r);
+ goto unreg_chardev;
+ }
+
+ for (i = 0; i < NUM_SMD_PKT_PORTS; ++i) {
+ smd_pkt_devp[i] = kzalloc(sizeof(struct smd_pkt_dev),
+ GFP_KERNEL);
+ if (IS_ERR(smd_pkt_devp[i])) {
+ r = PTR_ERR(smd_pkt_devp[i]);
+ pr_err("kmalloc() failed %d\n", r);
+ goto clean_cdevs;
+ }
+
+ smd_pkt_devp[i]->i = i;
+
+ init_waitqueue_head(&smd_pkt_devp[i]->ch_read_wait_queue);
+ smd_pkt_devp[i]->remote_open = 0;
+ init_waitqueue_head(&smd_pkt_devp[i]->ch_opened_wait_queue);
+
+ mutex_init(&smd_pkt_devp[i]->ch_lock);
+ mutex_init(&smd_pkt_devp[i]->rx_lock);
+ mutex_init(&smd_pkt_devp[i]->tx_lock);
+
+ cdev_init(&smd_pkt_devp[i]->cdev, &smd_pkt_fops);
+ smd_pkt_devp[i]->cdev.owner = THIS_MODULE;
+
+ r = cdev_add(&smd_pkt_devp[i]->cdev,
+ (smd_pkt_number + i), 1);
+ if (r) {
+ pr_err("cdev_add() failed %d\n", r);
+ kfree(smd_pkt_devp[i]);
+ goto clean_cdevs;
+ }
+
+ smd_pkt_devp[i]->devicep =
+ device_create(smd_pkt_classp, NULL,
+ (smd_pkt_number + i), NULL,
+ smd_pkt_dev_name[i]);
+ if (IS_ERR(smd_pkt_devp[i]->devicep)) {
+ r = PTR_ERR(smd_pkt_devp[i]->devicep);
+ pr_err("device_create() failed %d\n", r);
+ cdev_del(&smd_pkt_devp[i]->cdev);
+ kfree(smd_pkt_devp[i]);
+ goto clean_cdevs;
+ }
+
+ }
+
+ pr_info("SMD Packet Port Driver Initialized.\n");
+ return 0;
+
+clean_cdevs:
+ if (i > 0) {
+ while (--i >= 0) {
+ mutex_destroy(&smd_pkt_devp[i]->ch_lock);
+ mutex_destroy(&smd_pkt_devp[i]->rx_lock);
+ mutex_destroy(&smd_pkt_devp[i]->tx_lock);
+ cdev_del(&smd_pkt_devp[i]->cdev);
+ kfree(smd_pkt_devp[i]);
+ device_destroy(smd_pkt_classp,
+ MKDEV(MAJOR(smd_pkt_number), i));
+ }
+ }
+
+ class_destroy(smd_pkt_classp);
+unreg_chardev:
+ unregister_chrdev_region(MAJOR(smd_pkt_number), NUM_SMD_PKT_PORTS);
+ return r;
+}
+module_init(smd_pkt_init);
+
+static void __exit smd_pkt_cleanup(void)
+{
+ int i;
+
+ for (i = 0; i < NUM_SMD_PKT_PORTS; ++i) {
+ mutex_destroy(&smd_pkt_devp[i]->ch_lock);
+ mutex_destroy(&smd_pkt_devp[i]->rx_lock);
+ mutex_destroy(&smd_pkt_devp[i]->tx_lock);
+ cdev_del(&smd_pkt_devp[i]->cdev);
+ kfree(smd_pkt_devp[i]);
+ device_destroy(smd_pkt_classp,
+ MKDEV(MAJOR(smd_pkt_number), i));
+ }
+
+ class_destroy(smd_pkt_classp);
+ unregister_chrdev_region(MAJOR(smd_pkt_number), NUM_SMD_PKT_PORTS);
+}
+module_exit(smd_pkt_cleanup);
+
+MODULE_DESCRIPTION("MSM Shared Memory Packet Port");
+MODULE_LICENSE("GPL v2");
--
1.5.6.3
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