topic Re: IMX6q UART5 Bluetooth connection in i.MX Processors

IMX6q UART5 Bluetooth connection

saurabh206 — Thu, 17 Apr 2014 10:11:13 GMT

Hi,

All

I am using custom hardware based on IMX6q.

Bluetooth chip is connected on UART5.

Bluetooth pins imx6

BT_RXD --> KEY_COL1

BT_TXD --> KEY_ROW1

BT_CTS --> KEY_COL4

BT_RTS --> KEY_ROW4

Following code i have added to enable UART5.

static iomux_v3_cfg_t mx6q_uart5_pads[] = {

MX6Q_PAD_KEY_ROW1__UART5_RXD,

MX6Q_PAD_KEY_COL1__UART5_TXD,

MX6Q_PAD_KEY_ROW4__UART5_CTS,

MX6Q_PAD_KEY_COL4__UART5_RTS,

};

static const struct imxuart_platform_data mx6q_sd_uart5_data __initconst = {

.flags = IMXUART_HAVE_RTSCTS ,

.dma_req_rx = MX6Q_DMA_REQ_UART5_RX,

.dma_req_tx = MX6Q_DMA_REQ_UART5_TX,

};

static void __init uart5_init(void)

{

printk(KERN_INFO "uart5 is added\n");

mxc_iomux_v3_setup_multiple_pads(mx6q_uart5_pads,

ARRAY_SIZE(mx6q_uart5_pads));

imx6q_add_imx_uart(4, &mx6q_sd_uart5_data);

}

With this setup I am getting error for firmware load, It seems that my UART5 configuration is not proper.

How to debug RTS/CTS issue?

Re: IMX6q UART5 Bluetooth connection

jimmychan — Mon, 21 Apr 2014 07:27:38 GMT

Please check the UART setting (e.g. DMA enable, flow control setting) in the linux/arch/arm/mach-mx6/serial.h.

Re: IMX6q UART5 Bluetooth connection

saurabh206 — Mon, 21 Apr 2014 08:49:40 GMT

Hi,

Jimmychan

Thanks for the reply

UART settings are as follow.

#define UART5_UCR4_CTSTL

#define UART5_DMA_ENABLE 1

#define UART5_DMA_RXBUFSIZE	512
#define UART5_UFCR_RXTL	16
#define UART5_UFCR_TXTL	16

Thanks

Saurabh

Re: IMX6q UART5 Bluetooth connection

jimmychan — Mon, 21 Apr 2014 08:59:14 GMT

what is the error message when you load the firmware?

Re: IMX6q UART5 Bluetooth connection

alfred_liu — Mon, 21 Apr 2014 09:30:28 GMT

Hi, Patel

please exchange RX and TX.

RM document may descripe these two pins incorrectly.

if so , I will push document team to correct this error.

Re: IMX6q UART5 Bluetooth connection

saurabh206 — Tue, 22 Apr 2014 03:40:59 GMT

Hi,

I am using TiWi-BLE chip and TI_ST module. Please check error as follows.

(stk) :ldisc_install = 1

(stk) :ldisc installation timeout

(stk) :ldisc_install = 0

(stk) : timed out waiting for ldisc to be un-installed

Thanks

Saurabh

Re: IMX6q UART5 Bluetooth connection

saurabh206 — Tue, 22 Apr 2014 03:44:23 GMT

Hi,

Weisong

Thanks for reply.

I will try to change the RX and TX.

Can you describe the correct pin connection and configuration?

Thanks

Saurabh

Re: IMX6q UART5 Bluetooth connection

alfred_liu — Tue, 22 Apr 2014 08:59:32 GMT

Hi, Patel

I believe MX6Q_PAD_KEY_ROW1 is actual UART5_TX.

and MX6Q_PAD_KEY_COL1 is actual UART5_RX.

you can have a try.

Re: IMX6q UART5 Bluetooth connection

alfred_liu — Thu, 24 Apr 2014 02:51:27 GMT

Hi, Patel

any test result from you?

Re: IMX6q UART5 Bluetooth connection

saurabh206 — Thu, 24 Apr 2014 04:04:29 GMT

Hi,

Weisong

To test this we need to modified the hardware. Is there any alternative in software?

From following link

https://community.freescale.com/docs/DOC-97509

For the Uart IP, the CTS_B is always an output and RTS_B always an input. But the RTS_B & CTS_B IO will be swapped when UART operates in different DTE or DCE mode.

Is it possible that we change the RTS_B and CTS_B?

Thanks

Saurabh

Re: IMX6q UART5 Bluetooth connection

alfred_liu — Thu, 24 Apr 2014 05:30:37 GMT

Hi, Patel

the issue is not related to RTS and CTS, these two signals are just control signals.

the issue is that MX6Q_PAD_KEY_ROW1 is actual UART5_TX can not be used as UART5_RX.

so you can measure the waveform on TX and RX, you can see the data on MX6Q_PAD_KEY_ROW1 when you transmmit data.

Re: IMX6q UART5 Bluetooth connection

saurabh206 — Thu, 24 Apr 2014 06:47:22 GMT

Hi,

Thanks for your suggestions.

UART TX, RX, RTS, CTS pin remains always high.

I have tried to send the data to /dev/ttymxc4 using echo "abcd" > /dev/ttymxc4.

Re: IMX6q UART5 Bluetooth connection

saurabh206 — Thu, 24 Apr 2014 08:17:22 GMT

Hi,

Weisong

echo "abcd" > /dev/ttymxc4 gives output on BT_RX so I think MX6Q_PAD_KEY_COL1 is UART5 TX.

Thanks

Saurabh

Re: IMX6q UART5 Bluetooth connection

alfred_liu — Thu, 24 Apr 2014 09:08:18 GMT

Hi, Patel

It's very difficult to explain this to you.

we have done test on our SDB board.

yes, you can configure MX6Q_PAD_KEY_COL1 as UART5 TX and ROW1 as UART5_RX.

but when you send data to device, I believe you will capture data on ROW1 whcih should be on COL1.

anyway I will check with SOC design team to get the explaination.

please wait for my response.

Re: IMX6q UART5 Bluetooth connection

saurabh206 — Tue, 29 Apr 2014 10:14:10 GMT

Hi, Weisong

Is there any update?

Re: IMX6q UART5 Bluetooth connection

alfred_liu — Wed, 30 Apr 2014 07:54:49 GMT

Hi, Patel

SOC design team may need some time to verify it.

meanwhile, I suggest you do the test I mentioned.

Re: IMX6q UART5 Bluetooth connection

alfred_liu — Tue, 03 Jun 2014 05:57:27 GMT

Hi, Patel

could you help to dump out the following registers:

UART1:

0x021EC090

0x020e0280

0x020e0284

0x020e0920

UART5:

0x021f4090

0x020e0200

0x020e0204

0x020e0940

that would be helpful for use to locate the issue.

Re: IMX6q UART5 Bluetooth connection

saurabh206 — Tue, 03 Jun 2014 07:52:01 GMT

Weisong

I have fixed the UART issue.

My working setup is as follows

static iomux_v3_cfg_t mx6q_uart5_pads[] = {

MX6Q_PAD_KEY_ROW1__UART5_RXD,

MX6Q_PAD_KEY_COL1__UART5_TXD,

MX6Q_PAD_KEY_COL4__UART5_RTS,

MX6Q_PAD_KEY_ROW4__UART5_CTS,

};

And physically

BT RXD is connected to IMX6 TXD.

BT TXD is connected to IMX6 RXD.

BT RTS is connected to IMX6 RTS.

BT CTS is connected to IMX6 CTS.

Thanks

Saurabh.

Re: IMX6q UART5 Bluetooth connection

shehanrajendran — Mon, 23 Jun 2014 05:11:41 GMT

Saurabh,

I have a question on your working setup. Did you use IMXUART_USE_DCEDTE flag along with IMXUART_HAVE_RTSCTS? Or was that IMXUART_HAVE_RTSCTS alone?

Thanks,

Re: IMX6q UART5 Bluetooth connection

saurabh206 — Tue, 24 Jun 2014 11:07:46 GMT

I have used the IMXUART_HAVE_RTSCTS.

Saurabh