serial: 8250_dw: only get the clock rate in one place

The clock rate is requested from a property called
"clock-frequency" in both dw8250_probe_of and
dw8250_probe_acpi. Moving the requests to dw8250_probe.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 13 insertions, 17 deletions

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index cc943fe3fd68..176f18f2e3ab 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -374,17 +374,6 @@ static int dw8250_probe_of(struct uart_port *p,
                 data->msr_mask_off |= UART_MSR_TERI;
         }
 
-        /* clock got configured through clk api, all done */
-        if (p->uartclk)
-                return 0;
-
-        /* try to find out clock frequency from DT as fallback */
-        if (of_property_read_u32(np, "clock-frequency", &val)) {
-                dev_err(p->dev, "clk or clock-frequency not defined\n");
-                return -EINVAL;
-        }
-        p->uartclk = val;
-
         return 0;
 }
 
@@ -395,11 +384,6 @@ static int dw8250_probe_acpi(struct uart_8250_port *up,
 
         dw8250_setup_port(up);
 
-        if (!p->uartclk)
-                if (device_property_read_u32(p->dev, "clock-frequency",
-                                             &p->uartclk))
-                        return -EINVAL;
-
         p->iotype = UPIO_MEM32;
         p->serial_in = dw8250_serial_in32;
         p->serial_out = dw8250_serial_out32;
@@ -453,12 +437,18 @@ static int dw8250_probe(struct platform_device *pdev)
                 return -ENOMEM;
 
         data->usr_reg = DW_UART_USR;
+
+        /* Always ask for fixed clock rate from a property. */
+        device_property_read_u32(&pdev->dev, "clock-frequency",
+                                 &uart.port.uartclk);
+
+        /* If there is separate baudclk, get the rate from it. */
         data->clk = devm_clk_get(&pdev->dev, "baudclk");
         if (IS_ERR(data->clk) && PTR_ERR(data->clk) != -EPROBE_DEFER)
                 data->clk = devm_clk_get(&pdev->dev, NULL);
         if (IS_ERR(data->clk) && PTR_ERR(data->clk) == -EPROBE_DEFER)
                 return -EPROBE_DEFER;
-        if (!IS_ERR(data->clk)) {
+        if (!IS_ERR_OR_NULL(data->clk)) {
                 err = clk_prepare_enable(data->clk);
                 if (err)
                         dev_warn(&pdev->dev, "could not enable optional baudclk: %d\n",
@@ -467,6 +457,12 @@ static int dw8250_probe(struct platform_device *pdev)
                         uart.port.uartclk = clk_get_rate(data->clk);
         }
 
+        /* If no clock rate is defined, fail. */
+        if (!uart.port.uartclk) {
+                dev_err(&pdev->dev, "clock rate not defined\n");
+                return -EINVAL;
+        }
+
         data->pclk = devm_clk_get(&pdev->dev, "apb_pclk");
         if (IS_ERR(data->clk) && PTR_ERR(data->clk) == -EPROBE_DEFER) {
                 err = -EPROBE_DEFER;