serial: qcom_geni_serial: To correct QUP Version detection logic

commit c9ca43d upstream.

For QUP IP versions 2.5 and above the oversampling rate is
halved from 32 to 16.

Commit ce73460 ("tty: serial: qcom_geni_serial: Update
the oversampling rate") is pushed to handle this scenario.
But the existing logic is failing to classify QUP Version 3.0
into the correct group ( 2.5 and above).

As result Serial Engine clocks are not configured properly for
baud rate and garbage data is sampled to FIFOs from the line.

So, fix the logic to detect QUP with versions 2.5 and above.

Fixes: ce73460 ("tty: serial: qcom_geni_serial: Update the oversampling rate")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Paras Sharma <parashar@codeaurora.org>
Reviewed-by: Akash Asthana <akashast@codeaurora.org>
Link: https://lore.kernel.org/r/1601445926-23673-1-git-send-email-parashar@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/qcom_geni_serial.c

@@ -1000,7 +1000,7 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
 	sampling_rate = UART_OVERSAMPLING;
 	/* Sampling rate is halved for IP versions >= 2.5 */
 	ver = geni_se_get_qup_hw_version(&port->se);
-	if (GENI_SE_VERSION_MAJOR(ver) >= 2 && GENI_SE_VERSION_MINOR(ver) >= 5)
+	if (ver >= QUP_SE_VERSION_2_5)
 		sampling_rate /= 2;
 
 	clk_rate = get_clk_div_rate(baud, sampling_rate, &clk_div);

include/linux/qcom-geni-se.h

@@ -248,6 +248,9 @@ struct geni_se {
 #define GENI_SE_VERSION_MINOR(ver) ((ver & HW_VER_MINOR_MASK) >> HW_VER_MINOR_SHFT)
 #define GENI_SE_VERSION_STEP(ver) (ver & HW_VER_STEP_MASK)
 
+/* QUP SE VERSION value for major number 2 and minor number 5 */
+#define QUP_SE_VERSION_2_5                  0x20050000
+
 /*
  * Define bandwidth thresholds that cause the underlying Core 2X interconnect
  * clock to run at the named frequency. These baseline values are recommended