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authorSatish Chandra <x0141690@ti.com>2012-03-13 17:40:13 +0530
committerSimone Willett <swillett@nvidia.com>2012-03-15 18:25:42 -0700
commit64bd5c31714444a05b1e62057a5d7946114bb73c (patch)
tree5e73fcc9295fb8b876723ddf1d2633c5c93b3179
parent1e2245bc75e1169df29ac77d8f2adc22aad1e365 (diff)
GPS: GPS Char Driver for Texas Instrument's Connectivity Chip.
This enables the GPS driver for TI WL128x BT/FM/GPS combo devices. It will provide a character device for the TI GPS host software to access the GPS core on the WL128x. Bug 933797 Change-Id: If0ea53a1b246a88fc895a95599d8bd38689b72fc Signed-off-by: Satish Chandra <x0141690@ti.com> Reviewed-on: http://git-master/r/90110 Reviewed-by: Automatic_Commit_Validation_User Tested-by: Rakesh Goyal <rgoyal@nvidia.com> Reviewed-by: Maria Bornski <mbornski@nvidia.com> Reviewed-by: Sachin Nikam <snikam@nvidia.com>
-rw-r--r--drivers/misc/ti-st/Kconfig7
-rw-r--r--drivers/misc/ti-st/Makefile1
-rw-r--r--drivers/misc/ti-st/gps_drv.c804
3 files changed, 812 insertions, 0 deletions
diff --git a/drivers/misc/ti-st/Kconfig b/drivers/misc/ti-st/Kconfig
index abb5de1afce3..8f20ddaf0949 100644
--- a/drivers/misc/ti-st/Kconfig
+++ b/drivers/misc/ti-st/Kconfig
@@ -14,4 +14,11 @@ config TI_ST
are returned to relevant protocol drivers based on their
packet types.
+config ST_GPS
+ tristate "gps driver for ST"
+ select TI_ST
+ help
+ This enables the GPS driver for TI WL128x BT/FM/GPS combo devices.
+ It will provide a character device for the TI GPS host software to
+ access the GPS core on the WL128x.
endmenu
diff --git a/drivers/misc/ti-st/Makefile b/drivers/misc/ti-st/Makefile
index 78d7ebb14749..3f6d990912c2 100644
--- a/drivers/misc/ti-st/Makefile
+++ b/drivers/misc/ti-st/Makefile
@@ -4,3 +4,4 @@
#
obj-$(CONFIG_TI_ST) += st_drv.o
st_drv-objs := st_core.o st_kim.o st_ll.o
+obj-$(CONFIG_ST_GPS) += gps_drv.o
diff --git a/drivers/misc/ti-st/gps_drv.c b/drivers/misc/ti-st/gps_drv.c
new file mode 100644
index 000000000000..17ca92dd177b
--- /dev/null
+++ b/drivers/misc/ti-st/gps_drv.c
@@ -0,0 +1,804 @@
+/*
+ * GPS Char Driver for Texas Instrument's Connectivity Chip.
+ * Copyright (C) 2009 Texas Instruments
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+
+#include <linux/uaccess.h>
+#include <linux/tty.h>
+#include <linux/sched.h>
+
+#include <linux/delay.h>
+#include <linux/firmware.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/skbuff.h>
+#include <linux/interrupt.h>
+
+#include <linux/ti_wilink_st.h>
+
+#undef VERBOSE
+#undef DEBUG
+
+/* Debug macros*/
+#if defined(DEBUG) /* limited debug messages */
+#define GPSDRV_DBG(fmt, arg...) \
+ printk(KERN_INFO "[GPS] (gpsdrv):"fmt"\n" , ## arg)
+#define GPSDRV_VER(fmt, arg...)
+#elif defined(VERBOSE) /* very verbose */
+#define GPSDRV_DBG(fmt, arg...) \
+ printk(KERN_INFO "[GPS] (gpsdrv):"fmt"\n" , ## arg)
+#define GPSDRV_VER(fmt, arg...) \
+ printk(KERN_INFO "[GPS] (gpsdrv):"fmt"\n" , ## arg)
+#define GPSDRV_ERR(fmt, arg...) \
+ printk(KERN_ERR "[GPS] (gpsdrv):"fmt"\n" , ## arg)
+#else /* Error msgs only */
+#define GPSDRV_ERR(fmt, arg...) \
+ printk(KERN_ERR "[GPS] (gpsdrv):"fmt"\n" , ## arg)
+#define GPSDRV_VER(fmt, arg...)
+#define GPSDRV_DBG(fmt, arg...)
+#endif
+
+static void gpsdrv_tsklet_write(unsigned long data);
+
+/* List of error codes returned by the gps driver*/
+enum {
+ GPS_ERR_FAILURE = -1, /* check struct */
+ GPS_SUCCESS,
+ GPS_ERR_CLASS = -15,
+ GPS_ERR_CPY_TO_USR,
+ GPS_ERR_CPY_FRM_USR,
+ GPS_ERR_UNKNOWN,
+};
+
+/* Channel-9 details for GPS */
+#define GPS_CH9_PKT_HDR_SIZE 4
+#define GPS_CH9_PKT_NUMBER 0x9
+#define GPS_CH9_OP_WRITE 0x1
+#define GPS_CH9_OP_READ 0x2
+#define GPS_CH9_OP_COMPLETED_EVT 0x3
+
+/* Macros for Syncronising GPS registration and other R/W/ICTL operations */
+#define GPS_ST_REGISTERED 0
+#define GPS_ST_RUNNING 1
+
+/* Read time out defined to 10 seconds */
+#define GPSDRV_READ_TIMEOUT 10000
+/* Reg time out defined to 6 seconds */
+#define GPSDRV_REG_TIMEOUT 6000
+
+
+struct gpsdrv_event_hdr {
+ uint8_t opcode;
+ uint16_t plen;
+} __packed;
+
+/*
+ * struct gpsdrv_data - gps internal driver data
+ * @gpsdrv_reg_completed - completion to wait for registration
+ * @streg_cbdata - registration feedback
+ * @state - driver state
+ * @tx_count - TX throttling/unthrottling
+ * @st_write - write ptr from ST
+ * @rx_list - Rx data SKB queue
+ * @tx_list - Tx data SKB queue
+ * @gpsdrv_data_q - dataq checked up on poll/receive
+ * @lock - spin lock
+ * @gpsdrv_tx_tsklet - gps write task
+ */
+
+struct gpsdrv_data {
+ struct completion gpsdrv_reg_completed;
+ char streg_cbdata;
+ unsigned long state;
+ unsigned char tx_count;
+ long (*st_write) (struct sk_buff *skb);
+ struct sk_buff_head rx_list;
+ struct sk_buff_head tx_list;
+ wait_queue_head_t gpsdrv_data_q;
+ spinlock_t lock;
+ struct tasklet_struct gpsdrv_tx_tsklet;
+};
+
+#define DEVICE_NAME "tigps"
+
+/***********Functions called from ST driver**********************************/
+
+/* gpsdrv_st_recv Function
+ * This is Called in from -- ST Core when a data is received
+ * This is a registered callback with ST core when the gps driver registers
+ * with ST.
+ *
+ * Parameters:
+ * @skb : SKB buffer pointer which contains the incoming Ch-9 GPS data.
+ * Returns:
+ * GPS_SUCCESS - On Success
+ * else suitable error code
+ */
+long gpsdrv_st_recv(void *arg, struct sk_buff *skb)
+{
+ struct gpsdrv_event_hdr gpsdrv_hdr = { 0x00, 0x0000 };
+ struct gpsdrv_data *hgps = (struct gpsdrv_data *)arg;
+
+ /* SKB is NULL */
+ if (NULL == skb) {
+ GPSDRV_ERR("Input SKB is NULL");
+ return GPS_ERR_FAILURE;
+ }
+
+ /* Sanity Check - To Check if the Rx Pkt is Channel -9 or not */
+ if (0x09 != skb->cb[0]) {
+ GPSDRV_ERR("Input SKB is not a Channel-9 packet");
+ return GPS_ERR_FAILURE;
+ }
+ /* Copy Ch-9 info to local structure */
+ memcpy(&gpsdrv_hdr, skb->data, GPS_CH9_PKT_HDR_SIZE - 1);
+ skb_pull(skb, GPS_CH9_PKT_HDR_SIZE - 1);
+
+ /* check if skb->len and gpsdrv_hdr.plen are equal */
+ if (skb->len != gpsdrv_hdr.plen) {
+ GPSDRV_ERR("Received corrupted packet - Length Mismatch");
+ return -EINVAL;
+ }
+#ifdef VERBOSE
+ printk(KERN_INFO"data start >>\n");
+ print_hex_dump(KERN_INFO, ">in>", DUMP_PREFIX_NONE,
+ 16, 1, skb->data, skb->len, 0);
+ printk(KERN_INFO"\n<< end\n");
+#endif
+ /* Check the Opcode */
+ if ((gpsdrv_hdr.opcode != GPS_CH9_OP_READ) && (gpsdrv_hdr.opcode != \
+ GPS_CH9_OP_COMPLETED_EVT)) {
+ GPSDRV_ERR("Rec corrupt pkt opcode %x", gpsdrv_hdr.opcode);
+ return -EINVAL;
+ }
+
+ /* Strip Channel 9 packet information from SKB only
+ * if the opcode is GPS_CH9_OP_READ and get AI2 packet
+ */
+ if (GPS_CH9_OP_READ == gpsdrv_hdr.opcode) {
+ skb_queue_tail(&hgps->rx_list, skb);
+ wake_up_interruptible(&hgps->gpsdrv_data_q);
+ } else {
+ spin_lock(&hgps->lock);
+ /* The no. of Completed Packets is always 1
+ * in case of Channel 9 as per spec.
+ * Forcing it to 1 for precaution.
+ */
+ hgps->tx_count = 1;
+ /* Check if Tx queue and Tx count not empty */
+ if (!skb_queue_empty(&hgps->tx_list)) {
+ /* Schedule the Tx-task let */
+ spin_unlock(&hgps->lock);
+ GPSDRV_VER(" Scheduling tasklet to write");
+ tasklet_schedule(&hgps->gpsdrv_tx_tsklet);
+ } else {
+ spin_unlock(&hgps->lock);
+ }
+
+ GPSDRV_VER(" Tx count = %x", hgps->tx_count);
+ /* Free the received command complete SKB */
+ kfree_skb(skb);
+ }
+
+ return GPS_SUCCESS;
+
+}
+
+/* gpsdrv_st_cb Function
+ * This is Called in from -- ST Core when the state is pending during
+ * st_register. This is a registered callback with ST core when the gps
+ * driver registers with ST.
+ *
+ * Parameters:
+ * @data Status update of GPS registration
+ * Returns: NULL
+ */
+void gpsdrv_st_cb(void *arg, char data)
+{
+ struct gpsdrv_data *hgps = (struct gpsdrv_data *)arg;
+
+ GPSDRV_DBG(" Inside %s", __func__);
+ hgps->streg_cbdata = data; /* ST registration callback status */
+ complete_all(&hgps->gpsdrv_reg_completed);
+ return;
+}
+
+static struct st_proto_s gpsdrv_proto = {
+ .chnl_id = 0x09,
+ .max_frame_size = 1024,
+ .hdr_len = 3,
+ .offset_len_in_hdr = 1,
+ .len_size = 2,
+ .reserve = 1,
+ .recv = gpsdrv_st_recv,
+ .reg_complete_cb = gpsdrv_st_cb,
+};
+
+/** gpsdrv_tsklet_write Function
+ * This tasklet function will be scheduled when there is a data in Tx queue
+ * and GPS chip sent an command completion packet with non zero value.
+ *
+ * Parameters :
+ * @data : data passed to tasklet function
+ * Returns : NULL
+ */
+void gpsdrv_tsklet_write(unsigned long data)
+{
+ struct sk_buff *skb = NULL;
+ struct gpsdrv_data *hgps = (struct gpsdrv_data *)data;
+
+ GPSDRV_DBG(" Inside %s", __func__);
+
+ spin_lock(&hgps->lock);
+
+ /* Perform sanity check of verifying the status
+ to perform an st_write */
+ if (((!hgps->st_write) || (0 == hgps->tx_count))
+ || ((skb_queue_empty(&hgps->tx_list)))) {
+ spin_unlock(&hgps->lock);
+ GPSDRV_ERR("Sanity check Failed exiting %s", __func__);
+ return;
+ }
+ /* hgps->tx_list not empty skb already present
+ * dequeue the tx-data and perform a st_write
+ */
+ hgps->tx_count--;
+ spin_unlock(&hgps->lock);
+ GPSDRV_VER(" Tx count in gpsdrv_tsklet_write = %x", hgps->tx_count);
+ skb = skb_dequeue(&hgps->tx_list);
+ hgps->st_write(skb);
+
+ return;
+}
+
+/*********Functions Called from GPS host***************************************/
+
+/** gpsdrv_open Function
+ * This function will perform an register on ST driver.
+ *
+ * Parameters :
+ * @file : File pointer for GPS char driver
+ * @inod :
+ * Returns GPS_SUCCESS - on success
+ * else suitable error code
+ */
+int gpsdrv_open(struct inode *inod, struct file *file)
+{
+ int ret = 0;
+ unsigned long timeout = GPSDRV_REG_TIMEOUT;
+ struct gpsdrv_data *hgps;
+
+ GPSDRV_DBG(" Inside %s", __func__);
+
+ /* Allocate local resource memory */
+ hgps = kzalloc(sizeof(struct gpsdrv_data), GFP_KERNEL);
+ if (!(hgps)) {
+ GPSDRV_ERR("Can't allocate GPS data structure");
+ return -ENOMEM;
+ }
+
+ /* Initialize wait queue, skb queue head and
+ * registration complete strucuture
+ */
+ skb_queue_head_init(&hgps->rx_list);
+ skb_queue_head_init(&hgps->tx_list);
+ init_completion(&hgps->gpsdrv_reg_completed);
+ init_waitqueue_head(&hgps->gpsdrv_data_q);
+ spin_lock_init(&hgps->lock);
+
+ /* Check if GPS is already registered with ST */
+ if (test_and_set_bit(GPS_ST_REGISTERED, &hgps->state)) {
+ GPSDRV_ERR("GPS Registered/Registration in progress with ST"
+ " ,open called again?");
+ kfree(hgps);
+ return -EAGAIN;
+ }
+
+ /* Initialize gpsdrv_reg_completed so as to wait for completion
+ * on the same
+ * if st_register returns with a PENDING status
+ */
+ INIT_COMPLETION(hgps->gpsdrv_reg_completed);
+
+ gpsdrv_proto.priv_data = hgps;
+ /* Resgister GPS with ST */
+ ret = st_register(&gpsdrv_proto);
+ GPSDRV_VER(" st_register returned %d", ret);
+
+ /* If GPS Registration returned with error, then clear GPS_ST_REGISTERED
+ * for future open calls and return the appropriate error code
+ */
+ if (ret < 0 && ret != -EINPROGRESS) {
+ GPSDRV_ERR(" st_register failed");
+ clear_bit(GPS_ST_REGISTERED, &hgps->state);
+ if (ret == -EINPROGRESS)
+ return -EAGAIN;
+ return GPS_ERR_FAILURE;
+ }
+
+ /* if returned status is pending, wait for the completion */
+ if (ret == -EINPROGRESS) {
+ GPSDRV_VER(" GPS Register waiting for completion ");
+ timeout = wait_for_completion_timeout \
+ (&hgps->gpsdrv_reg_completed, msecs_to_jiffies(timeout));
+ /* Check for timed out condition */
+ if (0 == timeout) {
+ GPSDRV_ERR("GPS Device registration timed out");
+ clear_bit(GPS_ST_REGISTERED, &hgps->state);
+ return -ETIMEDOUT;
+ } else if (0 > hgps->streg_cbdata) {
+ GPSDRV_ERR("GPS Device Registration Failed-ST\n");
+ GPSDRV_ERR("RegCB called with ");
+ GPSDRV_ERR("Invalid value %d\n", hgps->streg_cbdata);
+ clear_bit(GPS_ST_REGISTERED, &hgps->state);
+ return -EAGAIN;
+ }
+ }
+ GPSDRV_DBG(" gps registration complete ");
+
+ /* Assign the write callback pointer */
+ hgps->st_write = gpsdrv_proto.write;
+ hgps->tx_count = 1;
+ file->private_data = hgps; /* set drv data */
+ tasklet_init(&hgps->gpsdrv_tx_tsklet, (void *)gpsdrv_tsklet_write,
+ (unsigned long)hgps);
+ set_bit(GPS_ST_RUNNING, &hgps->state);
+
+ return GPS_SUCCESS;
+}
+
+/** gpsdrv_release Function
+ * This function will un-registers from the ST driver.
+ *
+ * Parameters :
+ * @file : File pointer for GPS char driver
+ * @inod :
+ * Returns GPS_SUCCESS - on success
+ * else suitable error code
+ */
+int gpsdrv_release(struct inode *inod, struct file *file)
+{
+ struct gpsdrv_data *hgps = file->private_data;
+
+ GPSDRV_DBG(" Inside %s", __func__);
+
+ /* Disabling task-let 1st & then un-reg to avoid
+ * tasklet getting scheduled
+ */
+ tasklet_disable(&hgps->gpsdrv_tx_tsklet);
+ tasklet_kill(&hgps->gpsdrv_tx_tsklet);
+ /* Cleat registered bit if already registered */
+ if (test_and_clear_bit(GPS_ST_REGISTERED, &hgps->state)) {
+ if (st_unregister(&gpsdrv_proto) < 0) {
+ GPSDRV_ERR(" st_unregister failed");
+ /* Re-Enable the task-let if un-register fails */
+ tasklet_enable(&hgps->gpsdrv_tx_tsklet);
+ return GPS_ERR_FAILURE;
+ }
+ }
+
+ /* Reset Tx count value and st_write function pointer */
+ hgps->tx_count = 0;
+ hgps->st_write = NULL;
+ clear_bit(GPS_ST_RUNNING, &hgps->state);
+ GPSDRV_VER(" st_unregister success");
+
+ skb_queue_purge(&hgps->rx_list);
+ skb_queue_purge(&hgps->tx_list);
+ kfree(hgps);
+ file->private_data = NULL;
+
+ return GPS_SUCCESS;
+}
+
+/** gpsdrv_read Function
+ * This function will wait till the data received from the ST driver
+ * and then strips the GPS-Channel-9 header from the
+ * incoming AI2 packet and then send it to GPS host application.
+ *
+ * Parameters :
+ * @file : File pointer for GPS char driver
+ * @data : Data which needs to be passed to APP
+ * @size : Length of the data passesd
+ * offset :
+ * Returns Size of AI2 packet received - on success
+ * else suitable error code
+ */
+ssize_t gpsdrv_read(struct file *file, char __user *data, size_t size,
+ loff_t *offset)
+{
+ int len = 0, error = 0;
+ struct sk_buff *skb = NULL;
+ unsigned long timeout = GPSDRV_READ_TIMEOUT;
+ struct gpsdrv_data *hgps;
+
+ GPSDRV_DBG(" Inside %s", __func__);
+
+ /* Validate input parameters */
+ if ((NULL == file) || (((NULL == data) || (0 == size)))) {
+ GPSDRV_ERR("Invalid input params passed to %s", __func__);
+ return -EINVAL;
+ }
+
+ hgps = file->private_data;
+ /* Check if GPS is registered to perform read operation */
+ if (!test_bit(GPS_ST_RUNNING, &hgps->state)) {
+ GPSDRV_ERR("GPS Device is not running");
+ return -EINVAL;
+ }
+
+ /* cannot come here if poll-ed before reading
+ * if not poll-ed wait on the same wait_q
+ */
+ timeout = wait_event_interruptible_timeout(hgps->gpsdrv_data_q,
+ !skb_queue_empty(&hgps->rx_list), msecs_to_jiffies(timeout));
+ /* Check for timed out condition */
+ if (0 == timeout) {
+ GPSDRV_ERR("GPS Device Read timed out");
+ return -ETIMEDOUT;
+ }
+
+
+ /* hgps->rx_list not empty skb already present */
+ skb = skb_dequeue(&hgps->rx_list);
+
+ if (!skb) {
+ GPSDRV_ERR("Dequed SKB is NULL?");
+ return GPS_ERR_UNKNOWN;
+ } else if (skb->len > size) {
+ GPSDRV_DBG("SKB length is Greater than requested size ");
+ GPSDRV_DBG("Returning the available length of SKB\n");
+
+ error = copy_to_user(data, skb->data, size);
+ skb_pull(skb, size);
+
+ if (skb->len != 0)
+ skb_queue_head(&hgps->rx_list, skb);
+
+ /* printk(KERN_DEBUG "gpsdrv: total size read= %d", size);*/
+ return size;
+ }
+
+#ifdef VERBOSE
+ print_hex_dump(KERN_INFO, ">in>", DUMP_PREFIX_NONE,
+ 16, 1, skb->data, skb->len, 0);
+#endif
+
+ /* Forward the data to the user */
+ if (skb->len <= size) {
+ if (copy_to_user(data, skb->data, skb->len)) {
+ GPSDRV_ERR(" Unable to copy to user space");
+ /* Queue the skb back to head */
+ skb_queue_head(&hgps->rx_list, skb);
+ return GPS_ERR_CPY_TO_USR;
+ }
+ }
+
+ len = skb->len;
+ kfree_skb(skb);
+ /* printk(KERN_DEBUG "gpsdrv: total size read= %d", len); */
+ return len;
+}
+/* gpsdrv_write Function
+ * This function will pre-pend the GPS-Channel-9 header to the
+ * incoming AI2 packet sent from the GPS host application.
+ *
+ * Parameters :
+ * @file : File pointer for GPS char driver
+ * @data : AI2 packet data from GPS application
+ * @size : Size of the AI2 packet data
+ * @offset :
+ * Returns Size of AI2 packet on success
+ * else suitable error code
+ */
+ssize_t gpsdrv_write(struct file *file, const char __user *data,
+ size_t size, loff_t *offset)
+{
+ unsigned char channel = GPS_CH9_PKT_NUMBER; /* GPS Channel number */
+ /* Initialize gpsdrv_event_hdr with write opcode */
+ struct gpsdrv_event_hdr gpsdrv_hdr = { GPS_CH9_OP_WRITE, 0x0000 };
+ struct sk_buff *skb = NULL;
+ struct gpsdrv_data *hgps;
+
+ GPSDRV_DBG(" Inside %s", __func__);
+ /* Validate input parameters */
+ if ((NULL == file) || (((NULL == data) || (0 == size)))) {
+ GPSDRV_ERR("Invalid input params passed to %s", __func__);
+ return -EINVAL;
+ }
+
+ hgps = file->private_data;
+
+ /* Check if GPS is registered to perform write operation */
+ if (!test_bit(GPS_ST_RUNNING, &hgps->state)) {
+ GPSDRV_ERR("GPS Device is not running");
+ return -EINVAL;
+ }
+
+ if (!hgps->st_write) {
+ GPSDRV_ERR(" Can't write to ST, hgps->st_write null ?");
+ return -EINVAL;
+ }
+
+
+ skb = alloc_skb(size + GPS_CH9_PKT_HDR_SIZE, GFP_ATOMIC);
+ /* Validate Created SKB */
+ if (NULL == skb) {
+ GPSDRV_ERR("Error aaloacting SKB");
+ return -ENOMEM;
+ }
+
+ /* Update chnl-9 information with plen=AI2 pckt size which is "size"*/
+ gpsdrv_hdr.plen = size;
+
+ /* PrePend Channel-9 header to AI2 packet and write to SKB */
+ memcpy(skb_put(skb, 1), &channel, 1);
+ memcpy(skb_put(skb, GPS_CH9_PKT_HDR_SIZE - 1), &gpsdrv_hdr,
+ GPS_CH9_PKT_HDR_SIZE - 1);
+
+ /* Forward the data from the user space to ST core */
+ if (copy_from_user(skb_put(skb, size), data, size)) {
+ GPSDRV_ERR(" Unable to copy from user space");
+ kfree_skb(skb);
+ return GPS_ERR_CPY_FRM_USR;
+ }
+
+#ifdef VERBOSE
+ GPSDRV_VER("start data..");
+ print_hex_dump(KERN_INFO, "<out<", DUMP_PREFIX_NONE,
+ 16, 1, skb->data, size, 0);
+ GPSDRV_VER("\n..end data");
+#endif
+
+ /* Check if data can be sent to GPS chip
+ * If not, add it to queue and that can be sent later
+ */
+ spin_lock(&hgps->lock);
+ if (0 != hgps->tx_count) {
+ /* If TX Q is empty send current SKB;
+ * else, queue current SKB at end of tx_list queue and
+ * send first SKB in tx_list queue.
+ */
+ hgps->tx_count--;
+ spin_unlock(&hgps->lock);
+
+ GPSDRV_VER(" Tx count in gpsdrv_write = %x", hgps->tx_count);
+
+ if (skb_queue_empty(&hgps->tx_list)) {
+ hgps->st_write(skb);
+ } else {
+ skb_queue_tail(&hgps->tx_list, skb);
+ hgps->st_write(skb_dequeue(&hgps->tx_list));
+ }
+ } else {
+ /* Add it to TX queue */
+ spin_unlock(&hgps->lock);
+ GPSDRV_VER(" SKB added to Tx queue ");
+ GPSDRV_VER("Tx count = %x ", hgps->tx_count);
+ skb_queue_tail(&hgps->tx_list, skb);
+ /* This is added for precaution in the case that there is a
+ * context switch during the execution of the above lines.
+ * Redundant otherwise.
+ */
+ if ((0 != hgps->tx_count) && \
+ (!skb_queue_empty(&hgps->tx_list))) {
+ /* Schedule the Tx-task let */
+ GPSDRV_VER("Scheduling tasklet to write\n");
+ tasklet_schedule(&hgps->gpsdrv_tx_tsklet);
+ }
+ }
+
+ return size;
+}
+
+/** gpsdrv_ioctl Function
+ * This will peform the functions as directed by the command and command
+ * argument.
+ *
+ * Parameters :
+ * @file : File pointer for GPS char driver
+ * @cmd : IOCTL Command
+ * @arg : Command argument for IOCTL command
+ * Returns GPS_SUCCESS on success
+ * else suitable error code
+ */
+static long gpsdrv_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct sk_buff *skb = NULL;
+ int retCode = GPS_SUCCESS;
+ struct gpsdrv_data *hgps;
+
+ GPSDRV_DBG(" Inside %s", __func__);
+
+ /* Validate input parameters */
+ if ((NULL == file) || (0 == cmd)) {
+ GPSDRV_ERR("Invalid input parameters passed to %s", __func__);
+ return -EINVAL;
+ }
+
+ hgps = file->private_data;
+
+ /* Check if GPS is registered to perform IOCTL operation */
+ if (!test_bit(GPS_ST_RUNNING, &hgps->state)) {
+ GPSDRV_ERR("GPS Device is not running");
+ return -EINVAL;
+ }
+
+ switch (cmd) {
+ case TCFLSH:
+ GPSDRV_VER(" IOCTL TCFLSH invoked with %ld argument", arg);
+ switch (arg) {
+ /* purge Rx/Tx SKB list queues depending on arg value */
+ case TCIFLUSH:
+ skb_queue_purge(&hgps->rx_list);
+ break;
+ case TCOFLUSH:
+ skb_queue_purge(&hgps->tx_list);
+ break;
+ case TCIOFLUSH:
+ skb_queue_purge(&hgps->rx_list);
+ skb_queue_purge(&hgps->tx_list);
+ break;
+ default:
+ GPSDRV_ERR("Invalid Command passed for tcflush");
+ retCode = 0;
+ break;
+ }
+ break;
+ case FIONREAD:
+ /* Deque the SKB from the head if rx_list is not empty
+ * And update the argument with skb->len to provide
+ * the amount of data available in the available SKB
+ */
+ skb = skb_dequeue(&hgps->rx_list);
+ if (skb != NULL) {
+ *(unsigned int *)arg = skb->len;
+ /* Re-Store the SKB for furtur Read operations */
+ skb_queue_head(&hgps->rx_list, skb);
+ } else {
+ *(unsigned int *)arg = 0;
+ }
+ GPSDRV_DBG("returning %d\n", *(unsigned int *)arg);
+
+ break;
+ default:
+ GPSDRV_DBG("Un-Identified IOCTL %d", cmd);
+ retCode = 0;
+ break;
+ }
+
+ return retCode;
+}
+
+/** gpsdrv_poll Function
+ * This function will wait till some data is received to the gps driver from ST
+ *
+ * Parameters :
+ * @file : File pointer for GPS char driver
+ * @wait : POLL wait information
+ * Returns status of POLL on success
+ * else suitable error code
+ */
+static unsigned int gpsdrv_poll(struct file *file, poll_table *wait)
+{
+ unsigned long mask = 0;
+ struct gpsdrv_data *hgps = file->private_data;
+
+ /* Check if GPS is registered to perform read operation */
+ if (!test_bit(GPS_ST_RUNNING, &hgps->state)) {
+ GPSDRV_ERR("GPS Device is not running");
+ return -EINVAL;
+ }
+
+ /* Wait till data is signalled from gpsdrv_st_recv function
+ * with AI2 packet
+ */
+ poll_wait(file, &hgps->gpsdrv_data_q, wait);
+
+ if (!skb_queue_empty(&hgps->rx_list))
+ mask |= POLLIN; /* TODO: check app for mask */
+
+ return mask;
+}
+
+/* GPS Char driver function pointers
+ * These functions are called from USER space by pefroming File Operations
+ * on /dev/gps node exposed by this driver during init
+ */
+const struct file_operations gpsdrv_chrdev_ops = {
+ .owner = THIS_MODULE,
+ .open = gpsdrv_open,
+ .read = gpsdrv_read,
+ .write = gpsdrv_write,
+ .unlocked_ioctl = gpsdrv_ioctl,
+ .poll = gpsdrv_poll,
+ .release = gpsdrv_release,
+};
+
+/*********Functions called during insmod and delmod****************************/
+
+static int gpsdrv_major; /* GPS major number */
+static struct class *gpsdrv_class; /* GPS class during class_create */
+static struct device *gpsdrv_dev; /* GPS dev during device_create */
+/** gpsdrv_init Function
+ * This function Initializes the gps driver parametes and exposes
+ * /dev/gps node to user space
+ *
+ * Parameters : NULL
+ * Returns GPS_SUCCESS on success
+ * else suitable error code
+ */
+static int __init gpsdrv_init(void)
+{
+
+ GPSDRV_DBG(" Inside %s", __func__);
+
+ /* Expose the device DEVICE_NAME to user space
+ * And obtain the major number for the device
+ */
+ gpsdrv_major = register_chrdev(0, DEVICE_NAME, \
+ &gpsdrv_chrdev_ops);
+ if (0 > gpsdrv_major) {
+ GPSDRV_ERR("Error when registering to char dev");
+ return GPS_ERR_FAILURE;
+ }
+ GPSDRV_VER("allocated %d, %d", gpsdrv_major, 0);
+
+ /* udev */
+ gpsdrv_class = class_create(THIS_MODULE, DEVICE_NAME);
+ if (IS_ERR(gpsdrv_class)) {
+ GPSDRV_ERR(" Something went wrong in class_create");
+ unregister_chrdev(gpsdrv_major, DEVICE_NAME);
+ return GPS_ERR_CLASS;
+ }
+
+ gpsdrv_dev =
+ device_create(gpsdrv_class, NULL, MKDEV(gpsdrv_major, 0),
+ NULL, DEVICE_NAME);
+ if (IS_ERR(gpsdrv_dev)) {
+ GPSDRV_ERR(" Error in class_create");
+ unregister_chrdev(gpsdrv_major, DEVICE_NAME);
+ class_destroy(gpsdrv_class);
+ return GPS_ERR_CLASS;
+ }
+
+ return GPS_SUCCESS;
+}
+
+/** gpsdrv_exit Function
+ * This function Destroys the gps driver parametes and /dev/gps node
+ *
+ * Parameters : NULL
+ * Returns NULL
+ */
+static void __exit gpsdrv_exit(void)
+{
+ GPSDRV_DBG(" Inside %s", __func__);
+ GPSDRV_VER(" Bye.. freeing up %d", gpsdrv_major);
+
+ device_destroy(gpsdrv_class, MKDEV(gpsdrv_major, 0));
+ class_destroy(gpsdrv_class);
+ unregister_chrdev(gpsdrv_major, DEVICE_NAME);
+}
+
+module_init(gpsdrv_init);
+module_exit(gpsdrv_exit);
+MODULE_LICENSE("GPL");