[PATCH v5 3/3] tty: serial: qcom_geni_serial: Remove sysfs file

[PATCH v5 3/3] tty: serial: qcom_geni_serial: Remove sysfs file

[Akash Asthana]

Remove code from the driver that create and maintain loopback sysfs node.
Instead use the ioctl TIOCMSET with TIOCM_LOOP argument to set HW to
loopback mode.

Signed-off-by: Akash Asthana <akashast@codeaurora.org>
---
Changes in V5:
 - As per Greg's and Stephen's comment on v4 patch, removed loopback sysfs
   file related code.

 drivers/tty/serial/qcom_geni_serial.c | 30 ++++--------------------------
 1 file changed, 4 insertions(+), 26 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 56dad67..52f5ea2 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -165,30 +165,6 @@ static struct qcom_geni_serial_port qcom_geni_uart_ports[GENI_UART_PORTS] = {
 	},
 };
 
-static ssize_t loopback_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
-{
-	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
-
-	return snprintf(buf, sizeof(u32), "%d\n", port->loopback);
-}
-
-static ssize_t loopback_store(struct device *dev,
-				struct device_attribute *attr, const char *buf,
-				size_t size)
-{
-	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);
-	u32 loopback;
-
-	if (kstrtoint(buf, 0, &loopback) || loopback > MAX_LOOPBACK_CFG) {
-		dev_err(dev, "Invalid input\n");
-		return -EINVAL;
-	}
-	port->loopback = loopback;
-	return size;
-}
-static DEVICE_ATTR_RW(loopback);
-
 static struct qcom_geni_serial_port qcom_geni_console_port = {
 	.uport = {
 		.iotype = UPIO_MEM,
@@ -238,10 +214,14 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
 							unsigned int mctrl)
 {
 	u32 uart_manual_rfr = 0;
+	struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
 
 	if (uart_console(uport))
 		return;
 
+	if (mctrl & TIOCM_LOOP)
+		port->loopback = MAX_LOOPBACK_CFG;
+
 	if (!(mctrl & TIOCM_RTS))
 		uart_manual_rfr = UART_MANUAL_RFR_EN | UART_RFR_NOT_READY;
 	writel(uart_manual_rfr, uport->membase + SE_UART_MANUAL_RFR);
@@ -1311,8 +1291,6 @@ static int qcom_geni_serial_probe(struct platform_device *pdev)
 	uport->private_data = drv;
 	platform_set_drvdata(pdev, port);
 	port->handle_rx = console ? handle_rx_console : handle_rx_uart;
-	if (!console)
-		device_create_file(uport->dev, &dev_attr_loopback);
 
 	ret = uart_add_one_port(drv, uport);
 	if (ret)
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project

Re: [PATCH v5 3/3] tty: serial: qcom_geni_serial: Remove sysfs file

[Stephen Boyd]

Please update the subject. This patch does more than remove the sysfs
file. "Move loopback support to TIOCM_LOOP"?

Quoting Akash Asthana (2019-11-13 02:49:21)
> Remove code from the driver that create and maintain loopback sysfs node.
> Instead use the ioctl TIOCMSET with TIOCM_LOOP argument to set HW to
> loopback mode.
> 
> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
> ---
> Changes in V5:
>  - As per Greg's and Stephen's comment on v4 patch, removed loopback sysfs
>    file related code.
> 
>  drivers/tty/serial/qcom_geni_serial.c | 30 ++++--------------------------
>  1 file changed, 4 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
> index 56dad67..52f5ea2 100644
> --- a/drivers/tty/serial/qcom_geni_serial.c
> +++ b/drivers/tty/serial/qcom_geni_serial.c
> @@ -238,10 +214,14 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
>                                                         unsigned int mctrl)
>  {
>         u32 uart_manual_rfr = 0;
> +       struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
>  
>         if (uart_console(uport))
>                 return;
>  
> +       if (mctrl & TIOCM_LOOP)
> +               port->loopback = MAX_LOOPBACK_CFG;

How does this work? The loopback is supposed to be the max all the time
and not match some qup number or something?

Re: [PATCH v5 3/3] tty: serial: qcom_geni_serial: Remove sysfs file

[Akash Asthana]

On 11/14/2019 11:06 PM, Stephen Boyd wrote:
> Please update the subject. This patch does more than remove the sysfs
> file. "Move loopback support to TIOCM_LOOP"?
Ok, I will update this in next version.
> Quoting Akash Asthana (2019-11-13 02:49:21)
>> Remove code from the driver that create and maintain loopback sysfs node.
>> Instead use the ioctl TIOCMSET with TIOCM_LOOP argument to set HW to
>> loopback mode.
>>
>> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
>> ---
>> Changes in V5:
>>   - As per Greg's and Stephen's comment on v4 patch, removed loopback sysfs
>>     file related code.
>>
>>   drivers/tty/serial/qcom_geni_serial.c | 30 ++++--------------------------
>>   1 file changed, 4 insertions(+), 26 deletions(-)
>>
>> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
>> index 56dad67..52f5ea2 100644
>> --- a/drivers/tty/serial/qcom_geni_serial.c
>> +++ b/drivers/tty/serial/qcom_geni_serial.c
>> @@ -238,10 +214,14 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
>>                                                          unsigned int mctrl)
>>   {
>>          u32 uart_manual_rfr = 0;
>> +       struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
>>   
>>          if (uart_console(uport))
>>                  return;
>>   
>> +       if (mctrl & TIOCM_LOOP)
>> +               port->loopback = MAX_LOOPBACK_CFG;
> How does this work? The loopback is supposed to be the max all the time
> and not match some qup number or something?
port->loopback is unrelated to QUP number. However we have different 
modes to run loopback test, 1(rx-tx sorted), 2(cts-rts sorted),

3 or Max(rx-tx sorted and cts-rts sorted). In our internal testing we 
only use mode 3 hence we are initializing port->loopback variable

to 3 and eventually it will be written to HW register from set_termios 
call.

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project

Re: [PATCH v5 3/3] tty: serial: qcom_geni_serial: Remove sysfs file

[Stephen Boyd]

Quoting Akash Asthana (2019-11-15 01:57:48)
> 
> On 11/14/2019 11:06 PM, Stephen Boyd wrote:
> > Please update the subject. This patch does more than remove the sysfs
> > file. "Move loopback support to TIOCM_LOOP"?
> Ok, I will update this in next version.
> > Quoting Akash Asthana (2019-11-13 02:49:21)
> >> Remove code from the driver that create and maintain loopback sysfs node.
> >> Instead use the ioctl TIOCMSET with TIOCM_LOOP argument to set HW to
> >> loopback mode.
> >>
> >> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
> >> ---
> >> Changes in V5:
> >>   - As per Greg's and Stephen's comment on v4 patch, removed loopback sysfs
> >>     file related code.
> >>
> >>   drivers/tty/serial/qcom_geni_serial.c | 30 ++++--------------------------
> >>   1 file changed, 4 insertions(+), 26 deletions(-)
> >>
> >> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
> >> index 56dad67..52f5ea2 100644
> >> --- a/drivers/tty/serial/qcom_geni_serial.c
> >> +++ b/drivers/tty/serial/qcom_geni_serial.c
> >> @@ -238,10 +214,14 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
> >>                                                          unsigned int mctrl)
> >>   {
> >>          u32 uart_manual_rfr = 0;
> >> +       struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
> >>   
> >>          if (uart_console(uport))
> >>                  return;
> >>   
> >> +       if (mctrl & TIOCM_LOOP)
> >> +               port->loopback = MAX_LOOPBACK_CFG;
> > How does this work? The loopback is supposed to be the max all the time
> > and not match some qup number or something?
> port->loopback is unrelated to QUP number. However we have different 
> modes to run loopback test, 1(rx-tx sorted), 2(cts-rts sorted),
> 
> 3 or Max(rx-tx sorted and cts-rts sorted). In our internal testing we 
> only use mode 3 hence we are initializing port->loopback variable
> 
> to 3 and eventually it will be written to HW register from set_termios 
> call.

Ok. Thanks for clarifying. Can you rename this macro to
RX_TX_CTS_RTS_SORTED? I imagine seeing something like:

	/* SE_UART_LOOPBACK_CFG */
	#define RX_TX_SORTED		BIT(0)
	#define CTS_RTS_SORTED		BIT(1)
	#define RX_TX_CTS_RTS_SORTED	RX_TX_SORTED | CTS_RTS_SORTED

or whatever the bit field names really are.

Re: [PATCH v5 3/3] tty: serial: qcom_geni_serial: Remove sysfs file

[Akash Asthana]

On 11/16/2019 1:15 AM, Stephen Boyd wrote:
> Quoting Akash Asthana (2019-11-15 01:57:48)
>> On 11/14/2019 11:06 PM, Stephen Boyd wrote:
>>> Please update the subject. This patch does more than remove the sysfs
>>> file. "Move loopback support to TIOCM_LOOP"?
>> Ok, I will update this in next version.
>>> Quoting Akash Asthana (2019-11-13 02:49:21)
>>>> Remove code from the driver that create and maintain loopback sysfs node.
>>>> Instead use the ioctl TIOCMSET with TIOCM_LOOP argument to set HW to
>>>> loopback mode.
>>>>
>>>> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
>>>> ---
>>>> Changes in V5:
>>>>    - As per Greg's and Stephen's comment on v4 patch, removed loopback sysfs
>>>>      file related code.
>>>>
>>>>    drivers/tty/serial/qcom_geni_serial.c | 30 ++++--------------------------
>>>>    1 file changed, 4 insertions(+), 26 deletions(-)
>>>>
>>>> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
>>>> index 56dad67..52f5ea2 100644
>>>> --- a/drivers/tty/serial/qcom_geni_serial.c
>>>> +++ b/drivers/tty/serial/qcom_geni_serial.c
>>>> @@ -238,10 +214,14 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
>>>>                                                           unsigned int mctrl)
>>>>    {
>>>>           u32 uart_manual_rfr = 0;
>>>> +       struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
>>>>    
>>>>           if (uart_console(uport))
>>>>                   return;
>>>>    
>>>> +       if (mctrl & TIOCM_LOOP)
>>>> +               port->loopback = MAX_LOOPBACK_CFG;
>>> How does this work? The loopback is supposed to be the max all the time
>>> and not match some qup number or something?
>> port->loopback is unrelated to QUP number. However we have different
>> modes to run loopback test, 1(rx-tx sorted), 2(cts-rts sorted),
>>
>> 3 or Max(rx-tx sorted and cts-rts sorted). In our internal testing we
>> only use mode 3 hence we are initializing port->loopback variable
>>
>> to 3 and eventually it will be written to HW register from set_termios
>> call.
> Ok. Thanks for clarifying. Can you rename this macro to
> RX_TX_CTS_RTS_SORTED? I imagine seeing something like:
>
> 	/* SE_UART_LOOPBACK_CFG */
> 	#define RX_TX_SORTED		BIT(0)
> 	#define CTS_RTS_SORTED		BIT(1)
> 	#define RX_TX_CTS_RTS_SORTED	RX_TX_SORTED | CTS_RTS_SORTED
>
> or whatever the bit field names really are.
Ok, I will update this is v6.

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project