From ace65b453151845bc361f21f3e5b651c35f9f126 Mon Sep 17 00:00:00 2001
From: Jon Santmyer <jon@jonsantmyer.com>
Date: Wed, 22 May 2024 13:00:41 -0400
Subject: massive refactor for mp and organization

---
 device/serial.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 device/serial.c

(limited to 'device/serial.c')

diff --git a/device/serial.c b/device/serial.c
new file mode 100644
index 0000000..5000e0e
--- /dev/null
+++ b/device/serial.c
@@ -0,0 +1,77 @@
+#include "device/serial.h"
+#include "device/uart.h"
+#include "jove.h"
+
+serial_dev_t COM1;
+
+serial_dev_t 
+serial_new(uint16_t com)
+{
+    serial_dev_t dev = { .com = com };
+    serial_set_int(&dev, false);
+    serial_set_baud(&dev, 3);
+    serial_set_lcr(&dev, 1 | 2);
+    serial_set_fcr(&dev, 1 | 2 | 4 | 0xC0);
+    serial_set_fcr(&dev, 1 | 2 | 8);
+    serial_set_mcr(&dev, 1 | 2 | 4 | 8);
+    return dev;
+}
+
+void
+serial_set_int(serial_dev_t *dev, bool enable)
+{
+    poutb(SERIAL_UART_COM_IER(dev->com), enable);
+}
+
+void
+serial_set_baud(serial_dev_t *dev, uint16_t baud)
+{
+    /* Enable DLAB. */
+    poutb(SERIAL_UART_COM_LCR(dev->com), SERIAL_UART_COM_LCR(dev->com) | 0x80);
+    /* Write low & high bits. */
+    poutb(SERIAL_UART_COM_DLAB_DLL(dev->com), baud & 0xFF);
+    poutb(SERIAL_UART_COM_DLAB_DLH(dev->com), (baud >> 8) & 0xFF);
+    /* Disable DLAB. */
+    poutb(SERIAL_UART_COM_LCR(dev->com), SERIAL_UART_COM_LCR(dev->com) & 0x7F);
+}
+
+void
+serial_set_fcr(serial_dev_t *dev, uint16_t flg)
+{
+    poutb(SERIAL_UART_COM_FCR(dev->com), flg);
+}
+
+void
+serial_set_lcr(serial_dev_t *dev, uint16_t flg)
+{
+    poutb(SERIAL_UART_COM_LCR(dev->com), flg);
+}
+
+void
+serial_set_mcr(serial_dev_t *dev, uint16_t flg)
+{
+    poutb(SERIAL_UART_COM_MCR(dev->com), flg);
+}
+
+uint8_t
+serial_line_status(serial_dev_t *dev)
+{
+    return pinb(SERIAL_UART_COM_LSR(dev->com));
+}
+
+void
+serial_write(serial_dev_t *dev, const char *s, size_t len)
+{
+    for(; len > 0; len--) {
+        char c = *(s++);
+        while((serial_line_status(dev) & 0x20) == 0) {}
+        if(c == '\n') poutb(dev->com, '\r');
+        poutb(dev->com, c);
+    }
+}
+
+void
+serial_setup(void)
+{
+    COM1 = serial_new(SERIAL_UART_COM1);
+}
-- 
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