diff mbox

[2/3] tty: serial: fsl_lpuart: remove RTS/CTS control from set/get_mctrl

Message ID 1432886754-30115-3-git-send-email-bhuvanchandra.dv@toradex.com (mailing list archive)
State New, archived
Headers show

Commit Message

Bhuvanchandra DV May 29, 2015, 8:05 a.m. UTC 
The LPUART does not provide manual control of RTS/CTS signals,
those can only be controlled by the hardware directly. Therefore
manual control of those signals through mctrl can not be provided.
The current implementation enables/disables the automatic control,
which is not what mctrl should do, hence remove the incorrect
implementation.

Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
---
 drivers/tty/serial/fsl_lpuart.c | 56 ++++++++---------------------------------
 1 file changed, 10 insertions(+), 46 deletions(-)

Comments

Jakub Kici?ski May 29, 2015, 10:04 a.m. UTC | #1 
On Fri, 29 May 2015 13:35:53 +0530, Bhuvanchandra DV wrote:
> The LPUART does not provide manual control of RTS/CTS signals,
> those can only be controlled by the hardware directly. Therefore
> manual control of those signals through mctrl can not be provided.
> The current implementation enables/disables the automatic control,
> which is not what mctrl should do, hence remove the incorrect
> implementation.
> 
> Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>

Now that the functions do nothing there is probably no point in keeping
separate lpuart/lpuart32 variants.
Bhuvanchandra DV May 29, 2015, 10:10 a.m. UTC | #2 
Hello Jakub,

On 05/29/2015 03:34 PM, Jakub Kici?ski wrote:
> On Fri, 29 May 2015 13:35:53 +0530, Bhuvanchandra DV wrote:
>> The LPUART does not provide manual control of RTS/CTS signals,
>> those can only be controlled by the hardware directly. Therefore
>> manual control of those signals through mctrl can not be provided.
>> The current implementation enables/disables the automatic control,
>> which is not what mctrl should do, hence remove the incorrect
>> implementation.
>>
>> Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
>
> Now that the functions do nothing there is probably no point in keeping
> separate lpuart/lpuart32 variants.
Agreed, will update it accordingly.

Thanks! for pointing this.
>

Best regards,
Bhuvan
diff mbox

Patch

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 08ce76f..357f623 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -822,64 +822,28 @@  static unsigned int lpuart32_tx_empty(struct uart_port *port)
 
 static unsigned int lpuart_get_mctrl(struct uart_port *port)
 {
-	unsigned int temp = 0;
-	unsigned char reg;
-
-	reg = readb(port->membase + UARTMODEM);
-	if (reg & UARTMODEM_TXCTSE)
-		temp |= TIOCM_CTS;
-
-	if (reg & UARTMODEM_RXRTSE)
-		temp |= TIOCM_RTS;
-
-	return temp;
+	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR;
 }
 
 static unsigned int lpuart32_get_mctrl(struct uart_port *port)
 {
-	unsigned int temp = 0;
-	unsigned long reg;
-
-	reg = lpuart32_read(port->membase + UARTMODIR);
-	if (reg & UARTMODIR_TXCTSE)
-		temp |= TIOCM_CTS;
-
-	if (reg & UARTMODIR_RXRTSE)
-		temp |= TIOCM_RTS;
-
-	return temp;
+	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR;
 }
 
 static void lpuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
-	unsigned char temp;
-
-	temp = readb(port->membase + UARTMODEM) &
-			~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
-
-	if (mctrl & TIOCM_RTS)
-		temp |= UARTMODEM_RXRTSE;
-
-	if (mctrl & TIOCM_CTS)
-		temp |= UARTMODEM_TXCTSE;
-
-	writeb(temp, port->membase + UARTMODEM);
+    /*
+     * CTS/RTS can _only_ be handled
+     * automatically by the hardware.
+     */
 }
 
 static void lpuart32_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
-	unsigned long temp;
-
-	temp = lpuart32_read(port->membase + UARTMODIR) &
-			~(UARTMODIR_RXRTSE | UARTMODIR_TXCTSE);
-
-	if (mctrl & TIOCM_RTS)
-		temp |= UARTMODIR_RXRTSE;
-
-	if (mctrl & TIOCM_CTS)
-		temp |= UARTMODIR_TXCTSE;
-
-	lpuart32_write(temp, port->membase + UARTMODIR);
+    /*
+     * CTS/RTS can _only_ be handled
+     * automatically by the hardware.
+     */
 }
 
 static void lpuart_break_ctl(struct uart_port *port, int break_state)