Commit d4d6f03c authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Greg Kroah-Hartman
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serial: max310x: Try to get crystal clock rate from property 



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: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210517172930.83353-1-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 18ee37e1

drivers/tty/serial/max310x.c

+26 −14
Original line number Diff line number Diff line
@@ -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;

		}

	}



	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;