pwm: remove overflow check and fix Kconfig

An overflow function was checking values exceeding
2^32, but doing a string comparision. This lead to
overflows on any number starting with a character
bigger than '5'.
The overflow check is not needed because the 'sscanf'
function is used to parse values as unsigned long, and
this is already truncating values bigger than 2^32 to
that limit.

The dependencies on the Kconfig for the PWM support didn't
let you enable SPI support in the kernel. The correct
dependency should check for the platform SPI master.

Signed-off-by: Hector Palacios <hector.palacios@digi.com>

2 files changed, 1 insertions, 37 deletions

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 236bfeeaf741..c44227ebfa4e 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -23,7 +23,7 @@ config ATMEL_PWM
 
 config NS9XXX_PWM
 	tristate "Digi NS9XXX PWM support"
-	depends on ARCH_NS9XXX && !CC9P9215JS_SERIAL_PORTA && !SPI && !CC9P9215JS_SERIAL_PORTC_CTSRTSRXTX && !CC9P9215JS_SERIAL_PORTC_FULL
+	depends on ARCH_NS9XXX && !CC9P9215JS_SERIAL_PORTA && !CC9P9215JS_SPI && !CC9P9215JS_SERIAL_PORTC_CTSRTSRXTX && !CC9P9215JS_SERIAL_PORTC_FULL
 	help
 	  This option enables device driver support for the PWMC
 	  peripheral channels found on certain NetSilicon processors.
diff --git a/drivers/pwm/pwm.c b/drivers/pwm/pwm.c
index 44524228fe21..32e84f86bf62 100644
--- a/drivers/pwm/pwm.c
+++ b/drivers/pwm/pwm.c
@@ -39,28 +39,6 @@ static DEFINE_MUTEX(device_list_mutex);
 static struct class pwm_class;
 static struct workqueue_struct *pwm_handler_workqueue;
 
-/* Function that checks for overflows */
-static int check_flow(const char *buf)
-{
-
-	int i;
-	const char *overflow = "4294967295";
-
-	i = strcmp(buf, overflow);
-	pr_debug("buffer is ");
-	if (i < 0)
-		pr_debug("minor than");
-	else if (i > 0) {
-		pr_debug("greater than");
-		pr_err("This value is greater that 32-bit value.\n");
-		return -EINVAL;
-	} else
-		pr_debug("equals to");
-	pr_debug(" %s\n", overflow);
-
-	return 0;
-}
-
 int pwm_register(struct pwm_device *pwm)
 {
 	struct pwm_channel *p;
@@ -513,13 +491,6 @@ static ssize_t pwm_duty_ns_store(struct device *dev,
 {
 	unsigned long duty_ns;
 	struct pwm_channel *p = dev_get_drvdata(dev);
-	int ret;
-
-	ret = check_flow(buf);
-	if (ret) {
-		pr_err("Overflow or underflow detected.\n");
-		return -EINVAL;
-	}
 
 	if (1 == sscanf(buf, "%lu", &duty_ns))
 		pwm_set_duty_ns(p, duty_ns);
@@ -539,13 +510,6 @@ static ssize_t pwm_period_ns_store(struct device *dev,
 {
 	unsigned long period_ns;
 	struct pwm_channel *p = dev_get_drvdata(dev);
-	int ret;
-
-	ret = check_flow(buf);
-	if (ret) {
-		pr_err("Overflow or underflow detected.\n");
-		return -EINVAL;
-	}
 
 	if (1 == sscanf(buf, "%lu", &period_ns))
 		pwm_set_period_ns(p, period_ns);