[PATCH v4 4/6] tty: serial: amba-pl011: replace TIOCMBIT macros by static functions

From: Théo Lebrun
Date: Thu Nov 23 2023 - 08:43:03 EST


The driver uses two TIOCMBIT macros inside pl011_{get,set}_mctrl to
simplify the logic. Those look scary to checkpatch because they contain
ifs without do-while loops.

Avoid the macros by creating small equivalent static functions; that
lets the compiler do its type checking & avoids checkpatch errors.

For the second instance __assign_bit is not usable because it deals with
unsigned long pointers whereas we have an unsigned int in
pl011_set_mctrl.

Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Théo Lebrun <theo.lebrun@xxxxxxxxxxx>
---
drivers/tty/serial/amba-pl011.c | 45 ++++++++++++++++++++++-------------------
1 file changed, 24 insertions(+), 21 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 3beac358909f..cf9aefe2fd28 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1594,6 +1594,12 @@ static unsigned int pl011_tx_empty(struct uart_port *port)
0 : TIOCSER_TEMT;
}

+static void pl011_maybe_set_bit(bool cond, unsigned int *ptr, unsigned int mask)
+{
+ if (cond)
+ *ptr |= mask;
+}
+
static unsigned int pl011_get_mctrl(struct uart_port *port)
{
struct uart_amba_port *uap =
@@ -1601,18 +1607,22 @@ static unsigned int pl011_get_mctrl(struct uart_port *port)
unsigned int result = 0;
unsigned int status = pl011_read(uap, REG_FR);

-#define TIOCMBIT(uartbit, tiocmbit) \
- if (status & uartbit) \
- result |= tiocmbit
+ pl011_maybe_set_bit(status & UART01x_FR_DCD, &result, TIOCM_CAR);
+ pl011_maybe_set_bit(status & uap->vendor->fr_dsr, &result, TIOCM_DSR);
+ pl011_maybe_set_bit(status & uap->vendor->fr_cts, &result, TIOCM_CTS);
+ pl011_maybe_set_bit(status & uap->vendor->fr_ri, &result, TIOCM_RNG);

- TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR);
- TIOCMBIT(uap->vendor->fr_dsr, TIOCM_DSR);
- TIOCMBIT(uap->vendor->fr_cts, TIOCM_CTS);
- TIOCMBIT(uap->vendor->fr_ri, TIOCM_RNG);
-#undef TIOCMBIT
return result;
}

+static void pl011_assign_bit(bool cond, unsigned int *ptr, unsigned int mask)
+{
+ if (cond)
+ *ptr |= mask;
+ else
+ *ptr &= ~mask;
+}
+
static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct uart_amba_port *uap =
@@ -1621,23 +1631,16 @@ static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)

cr = pl011_read(uap, REG_CR);

-#define TIOCMBIT(tiocmbit, uartbit) \
- if (mctrl & tiocmbit) \
- cr |= uartbit; \
- else \
- cr &= ~uartbit
-
- TIOCMBIT(TIOCM_RTS, UART011_CR_RTS);
- TIOCMBIT(TIOCM_DTR, UART011_CR_DTR);
- TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1);
- TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2);
- TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE);
+ pl011_assign_bit(mctrl & TIOCM_RTS, &cr, UART011_CR_RTS);
+ pl011_assign_bit(mctrl & TIOCM_DTR, &cr, UART011_CR_DTR);
+ pl011_assign_bit(mctrl & TIOCM_OUT1, &cr, UART011_CR_OUT1);
+ pl011_assign_bit(mctrl & TIOCM_OUT2, &cr, UART011_CR_OUT2);
+ pl011_assign_bit(mctrl & TIOCM_LOOP, &cr, UART011_CR_LBE);

if (port->status & UPSTAT_AUTORTS) {
/* We need to disable auto-RTS if we want to turn RTS off */
- TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN);
+ pl011_assign_bit(mctrl & TIOCM_RTS, &cr, UART011_CR_RTSEN);
}
-#undef TIOCMBIT

pl011_write(cr, uap, REG_CR);
}

--
2.42.0