Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Jiri Slaby <jirislaby@kernel.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Dennis Giaya <dgiaya@whoi.edu>
Subject: [PATCH v1 1/1] serial: max310x: Use clock-names property matching to recognize XTAL
Date:   Thu, 22 Jul 2021 18:02:33 +0300
Message-Id: <20210722150233.30897-1-andriy.shevchenko@linux.intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Dennis reported that on ACPI-based systems the clock frequency
isn't enough to configure device properly. We have to respect
the clock source as well. To achieve this match the clock-names
property against "xtal" to recognize crystal connection.

Reported-by: Dennis Giaya <dgiaya@whoi.edu>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/tty/serial/max310x.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index ef11860cd69e..e2ab8d4eb7ad 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -1271,18 +1271,13 @@ static int max310x_probe(struct device *dev, const struct max310x_devtype *devty
 	/* 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");
+	xtal = device_property_match_string(dev, "clock-names", "xtal") >= 0;
+	if (xtal)
+		s->clk = devm_clk_get_optional(dev, "xtal");
+	else
+		s->clk = devm_clk_get_optional(dev, "osc");
 	if (IS_ERR(s->clk))
 		return PTR_ERR(s->clk);
-	if (s->clk) {
-		xtal = false;
-	} else {
-		s->clk = devm_clk_get_optional(dev, "xtal");
-		if (IS_ERR(s->clk))
-			return PTR_ERR(s->clk);
-
-		xtal = true;
-	}
 
 	ret = clk_prepare_enable(s->clk);
 	if (ret)
-- 
2.30.2