@@ -552,7 +552,7 @@ static int max310x_update_best_err(unsigned long f, long *besterr)
return 1;
}
-static int max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
+static u32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
unsigned long freq, bool xtal)
{
unsigned int div, clksrc, pllcfg = 0;
@@ -618,7 +618,7 @@ static int max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
}
}
- return (int)bestfreq;
+ return bestfreq;
}
static void max310x_batch_write(struct uart_port *port, u8 *txbuf, unsigned int len)
@@ -1253,9 +1253,10 @@ static int max310x_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
static int max310x_probe(struct device *dev, const struct max310x_devtype *devtype,
struct regmap *regmap, int irq)
{
- int i, ret, fmin, fmax, freq, uartclk;
+ int i, ret, fmin, fmax, freq;
struct max310x_port *s;
- bool xtal = false;
+ u32 uartclk = 0;
+ bool xtal;
if (IS_ERR(regmap))
return PTR_ERR(regmap);
@@ -1267,24 +1268,20 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty
return -ENOMEM;
}
+ /* Always ask for fixed clock rate from a property. */
+ device_property_read_u32(dev, "clock-frequency", &uartclk);
+
s->clk = devm_clk_get_optional(dev, "osc");
if (IS_ERR(s->clk))
return PTR_ERR(s->clk);
if (s->clk) {
- fmin = 500000;
- fmax = 35000000;
+ xtal = false;
} else {
s->clk = devm_clk_get_optional(dev, "xtal");
if (IS_ERR(s->clk))
return PTR_ERR(s->clk);
- if (s->clk) {
- fmin = 1000000;
- fmax = 4000000;
- xtal = true;
- } else {
- dev_err(dev, "Cannot get clock\n");
- return -EINVAL;
- }
+
+ xtal = true;
}
ret = clk_prepare_enable(s->clk);
@@ -1292,6 +1289,21 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty
return ret;
freq = clk_get_rate(s->clk);
+ if (freq == 0)
+ freq = uartclk;
+ if (freq == 0) {
+ dev_err(dev, "Cannot get clock rate\n");
+ return -EINVAL;
+ }
+
+ if (xtal) {
+ fmin = 1000000;
+ fmax = 4000000;
+ } else {
+ fmin = 500000;
+ fmax = 35000000;
+ }
+
/* Check frequency limits */
if (freq < fmin || freq > fmax) {
ret = -ERANGE;
In some configurations, mainly ACPI-based, the clock frequency of the device is supplied by very well established 'clock-frequency' property. Hence, try to get it from the property at last if no other providers are available. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- drivers/tty/serial/max310x.c | 40 +++++++++++++++++++++++------------- 1 file changed, 26 insertions(+), 14 deletions(-)