Changes in kernel/genarch/src/drivers/ns16550/ns16550.c [28a5ebd:39e1b9a] in mainline

File:

• kernel/genarch/src/drivers/ns16550/ns16550.c (modified) (1 diff)

kernel/genarch/src/drivers/ns16550/ns16550.c

@@ -112 +112 @@
 }
 
-static void ns16550_putuchar(outdev_t *dev, char32_t ch)
+static void ns16550_write(outdev_t *dev, const char *s, size_t n)
 {
         ns16550_instance_t *instance = (ns16550_instance_t *) dev->data;
 
-        if ((!instance->parea.mapped) || (console_override)) {
-                if (ch == '\n')
+        if (instance->parea.mapped && !console_override)
+                return;
+
+        const char *top = s + n;
+        assert(top >= s);
+
+        for (; s < top; s++) {
+                if (*s == '\n')
                         ns16550_sendb(instance, '\r');
 
-                if (ascii_check(ch))
-                        ns16550_sendb(instance, (uint8_t) ch);
-                else
-                        ns16550_sendb(instance, U_SPECIAL);
+                ns16550_sendb(instance, (uint8_t) *s);
         }
 }
 
 static outdev_operations_t ns16550_ops = {
-        .write = ns16550_putuchar,
+        .write = ns16550_write,
         .redraw = NULL
 };
+
+/** Configure ns16550 transmission format.
+ *
+ * @param instance   NS 16550 driver instance.
+ * @param baud_rate  Transmission speed in bits per second, also known as baud,
+ *                   maximum value is 115200.
+ * @param lcr_format Line Control Register configuration bits, as defined by
+ *                   the @c LCR_ macros.  These configure the word width,
+ *                   parity type, and stop bit count.
+ */
+void ns16550_format_set(ns16550_instance_t *instance,
+    unsigned baud_rate, uint8_t lcr_format)
+{
+        uint16_t divisor;
+
+        divisor = (uint16_t)(NS156440_CLOCK / baud_rate);
+        if (divisor == 0)
+                divisor = 1;  /* Avoid division by zero. */
+
+        ns16550_reg_write(instance, NS16550_REG_LCR, LCR_DLAB);
+        ns16550_reg_write(instance, NS16550_REG_DLL, divisor & 0xFF);
+        ns16550_reg_write(instance, NS16550_REG_DLH, (divisor >> 8) & 0xFF);
+        ns16550_reg_write(instance, NS16550_REG_LCR, lcr_format & ~LCR_DLAB);
+}
 
 /** Initialize ns16550.