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tty: omap-serial: pull out calculation from baud_is_mode16
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To determine the correct divisor, we need to know the difference between
the desired baud rate and the actual baud rate. The calculation for this
difference is implemented twice within omap_serial_baud_is_mode16().
Pull out the calculation for easier maintenance.

While at it, remove the CamelCasing from the variable names.

Signed-off-by: Frans Klaver <frans.klaver@xsens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Frans Klaver authored and Greg Kroah-Hartman committed Sep 29, 2014
1 parent dc31875 commit 13d6ceb
Showing 1 changed file with 24 additions and 18 deletions.
42 changes: 24 additions & 18 deletions drivers/tty/serial/omap-serial.c
Original file line number Diff line number Diff line change
Expand Up @@ -238,6 +238,26 @@ static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable)
pdata->enable_wakeup(up->dev, enable);
}

/*
* Calculate the absolute difference between the desired and actual baud
* rate for the given mode.
*/
static inline int calculate_baud_abs_diff(struct uart_port *port,
unsigned int baud, unsigned int mode)
{
unsigned int n = port->uartclk / (mode * baud);
int abs_diff;

if (n == 0)
n = 1;

abs_diff = baud - (port->uartclk / (mode * n));
if (abs_diff < 0)
abs_diff = -abs_diff;

return abs_diff;
}

/*
* serial_omap_baud_is_mode16 - check if baud rate is MODE16X
* @port: uart port info
Expand All @@ -252,24 +272,10 @@ static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable)
static bool
serial_omap_baud_is_mode16(struct uart_port *port, unsigned int baud)
{
unsigned int n13 = port->uartclk / (13 * baud);
unsigned int n16 = port->uartclk / (16 * baud);
int baudAbsDiff13;
int baudAbsDiff16;

if (n13 == 0)
n13 = 1;
if (n16 == 0)
n16 = 1;

baudAbsDiff13 = baud - (port->uartclk / (13 * n13));
baudAbsDiff16 = baud - (port->uartclk / (16 * n16));
if (baudAbsDiff13 < 0)
baudAbsDiff13 = -baudAbsDiff13;
if (baudAbsDiff16 < 0)
baudAbsDiff16 = -baudAbsDiff16;

return (baudAbsDiff13 >= baudAbsDiff16);
int abs_diff_13 = calculate_baud_abs_diff(port, baud, 13);
int abs_diff_16 = calculate_baud_abs_diff(port, baud, 16);

return (abs_diff_13 >= abs_diff_16);
}

/*
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