From: Anantha Krishnan <ananthk@codeaurora.org>
Date: Wed, 4 Feb 2015 12:29:07 +0530
Subject: [PATCH] bluetooth: Vote UART CLK ON prior to firmware download
 process

Before starting the firmware download process, vote UART CLK ON
to avoid triggering the dynamic suspend of UART driver. Post
firmware download and in error scenarios vote UART CLK OFF.

As per design, the UART driver enters into dynamic suspend if
there are no activity on the UART lines for 100ms. Depending upon
the rampatch size, the BT Controller takes time to apply the
downloaded rampatch segments and in sending the vendor specific
event. If the BT Controller takes > 100ms time in sending the
vendor specific event, the UART driver enters into suspend state.

As a result, UART driver fails to process the last vendor specific
event sent by the BT Controller. The VSE sent by BT Controller
wakes up the UART driver, but the data is not processed causing
firmware download failures.

Hence, vote UART CLK ON prior to firmware download process and
vote UART CLK OFF post firmware download proess and in error
scenarios.

Change-Id: I447ded33ad1cfaa020b491effce368fbfe41f894
---
 tools/hciattach_rome.c | 13 +++++++++++++
 tools/hciattach_rome.h |  2 ++
 2 files changed, 15 insertions(+)

diff --git a/tools/hciattach_rome.c b/tools/hciattach_rome.c
index fee36f904e04..574ceac6c750 100644
--- a/tools/hciattach_rome.c
+++ b/tools/hciattach_rome.c
@@ -1762,6 +1762,14 @@ int qca_soc_init(int fd, int speed, char *bdaddr)
     int size, local_baud_rate = 0, controller_baud_rate = 0;
 
     vnd_userial.fd = fd;
+
+    /* Vote for UART CLK prior to FW download */
+    err = ioctl(fd, USERIAL_OP_CLK_ON);
+    if (err < 0) {
+        fprintf(stderr, "%s: Failed to vote UART CLK ON\n", __func__);
+        return -1;
+    }
+
     /* Get Rome version information */
     if((err = rome_patch_ver_req(fd)) <0){
         fprintf(stderr, "%s: Fail to get Rome Version (0x%x)\n", __FUNCTION__, err);
@@ -1899,5 +1907,10 @@ download:
     }
 
 error:
+    /* Vote UART CLK OFF post to FW download */
+    err = ioctl(fd, USERIAL_OP_CLK_OFF);
+    if (err < 0)
+        fprintf(stderr, "%s: Failed to vote UART CLK OFF!!!\n", __func__);
+
     return err;
 }
diff --git a/tools/hciattach_rome.h b/tools/hciattach_rome.h
index 95d5f1e8a5c2..20264f9978d9 100644
--- a/tools/hciattach_rome.h
+++ b/tools/hciattach_rome.h
@@ -42,6 +42,8 @@
 #define BD_ADDR_LEN         6
 #define MSM_ENABLE_FLOW_CTRL   16
 #define MSM_DISABLE_FLOW_CTRL  17
+#define USERIAL_OP_CLK_ON      0x5441
+#define USERIAL_OP_CLK_OFF     0x5442
 
 unsigned char vnd_local_bd_addr[6] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
 typedef enum {