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serial: samsung: Register cpufreq notifier only on S3C24xx 

The Samsung serial driver registered for CPU frequency transitions to
recalculate its clock when ARM clock frequency changes.  This is needed
only on S3C24xx platform so limit the ifdef to respective cpufreq
driver.

On S3C24xx the ratio ratio between frequencies of UART's parent clock
(pclk) and ARM's parent clock (fclk) remains fixed.  Therefore when ARM
clock frequency goes down, the serial is also affected.

Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hifive-unleashed-5.1
Krzysztof Kozlowski 2016-06-27 13:59:08 +02:00 committed by Greg Kroah-Hartman
parent 5bf5635ac1
commit ebaa81c728
2 changed files with 2 additions and 2 deletions
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2
drivers/tty/serial/samsung.c
View File

@ -1577,7 +1577,7 @@ static void s3c24xx_serial_resetport(struct uart_port *port,
}
#ifdef CONFIG_CPU_FREQ
#ifdef CONFIG_ARM_S3C24XX_CPUFREQ
static int s3c24xx_serial_cpufreq_transition(struct notifier_block *nb,
unsigned long val, void *data)

2
drivers/tty/serial/samsung.h
View File

@ -102,7 +102,7 @@ struct s3c24xx_uart_port {
struct s3c24xx_uart_dma *dma;
#ifdef CONFIG_CPU_FREQ
#ifdef CONFIG_ARM_S3C24XX_CPUFREQ
struct notifier_block freq_transition;
#endif
};