[PATCH] libchip/ns16550: Allow user calculate baud divisor

[G S Niteesh]

This patch will allow the user to pass a function to calculate
the baud divisor.
This is will allow for more flexibility, since for some BSP's
like raspberrypi, the calculate of baud divisor is different
from what is in the current driver.
---
 bsps/include/libchip/ns16550.h           | 11 ++++++++---
 bsps/shared/dev/serial/ns16550-context.c |  6 ++++--
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/bsps/include/libchip/ns16550.h b/bsps/include/libchip/ns16550.h
index f053c8767f9..ab7992fd30b 100644
--- a/bsps/include/libchip/ns16550.h
+++ b/bsps/include/libchip/ns16550.h
@@ -1,6 +1,6 @@
 /**
  *  @file
- *  
+ *
  */
 
 /*
@@ -60,7 +60,11 @@ typedef uint8_t (*ns16550_get_reg)(uintptr_t port, uint8_t reg);
 
 typedef void (*ns16550_set_reg)(uintptr_t port, uint8_t reg, uint8_t value);
 
-typedef struct {
+typedef struct ns16550_context ns16550_context;
+
+typedef uint32_t (*ns16550_calculate_baud_divisor)(ns16550_context *ctx, uint32_t baud);
+
+struct ns16550_context{
   rtems_termios_device_context base;
   ns16550_get_reg get_reg;
   ns16550_set_reg set_reg;
@@ -70,6 +74,7 @@ typedef struct {
   uint32_t initial_baud;
   bool has_fractional_divider_register;
   bool has_precision_clock_synthesizer;
+  ns16550_calculate_baud_divisor calculate_baud_divisor;
   uint8_t modem_control;
   uint8_t line_control;
   uint32_t baud_divisor;
@@ -78,7 +83,7 @@ typedef struct {
   size_t out_current;
   const char *out_buf;
   rtems_termios_tty *tty;
-} ns16550_context;
+};
 
 extern const rtems_termios_device_handler ns16550_handler_interrupt;
 extern const rtems_termios_device_handler ns16550_handler_polled;
diff --git a/bsps/shared/dev/serial/ns16550-context.c b/bsps/shared/dev/serial/ns16550-context.c
index ce55b8309cc..70e73fc8c93 100644
--- a/bsps/shared/dev/serial/ns16550-context.c
+++ b/bsps/shared/dev/serial/ns16550-context.c
@@ -1,6 +1,6 @@
 /**
  *  @file
- *  
+ *
  *  This file contains the TTY driver for the National Semiconductor NS16550.
  *
  *  This part is widely cloned and second sourced.  It is found in a number
@@ -112,6 +112,8 @@ static uint32_t NS16550_GetBaudDivisor(ns16550_context *ctx, uint32_t baud)
       NS16550_FRACTIONAL_DIVIDER,
       fractionalDivider
     );
+  } else if (ctx->calculate_baud_divisor != NULL) {
+    baudDivisor = ctx->calculate_baud_divisor(ctx, baud);
   }
 
   return baudDivisor;
@@ -165,7 +167,7 @@ bool ns16550_probe(rtems_termios_device_context *base)
 
   ctx->modem_control = SP_MODEM_IRQ;
 
-  pNS16550 = ctx->port;    
+  pNS16550 = ctx->port;
   setReg   = ctx->set_reg;
   getReg   = ctx->get_reg;
 
-- 
2.17.1