Add a driver for Intel 8253-compatible PIT (#93)

Makefile.am

@@ -56,17 +56,6 @@ if ASM_X86_64
 libkernaux_la_SOURCES += src/asm/x86_64.S
 endif
 
-###########
-# Drivers #
-###########
-
-if WITH_DRIVERS
-libkernaux_la_SOURCES += \
-	src/drivers/console.c \
-	src/drivers/framebuffer.c \
-	src/drivers/intel_8259_pic.c
-endif
-
 ####################
 # Default packages #
 ####################
@@ -115,3 +104,26 @@ endif
 if WITH_UNITS
 libkernaux_la_SOURCES += src/units.c
 endif
+
+###########
+# Drivers #
+###########
+
+if WITH_DRIVERS
+libkernaux_la_SOURCES += \
+	src/drivers/console.c \
+	src/drivers/framebuffer.c
+
+# Intel 8253-compatible programmable interval timer
+
+if ASM_I386
+libkernaux_la_SOURCES += src/drivers/intel_8253_pit.c
+endif
+
+# Intel 8259-compatible programmable interrupt controller
+
+if ASM_I386
+libkernaux_la_SOURCES += src/drivers/intel_8259_pic.c
+endif
+
+endif # WITH_DRIVERS

README.md

@@ -90,7 +90,8 @@ zero). Work-in-progress APIs can change at any time.
 * Device drivers (for debugging only)
   * [Serial console](/include/kernaux/drivers/console.h) (*work in progress*)
   * [Framebuffer](/include/kernaux/drivers/framebuffer.h) (*planned*)
-  * [Intel 8259 PIC](/include/kernaux/drivers/intel_8259_pic.h) (*planned*)
+  * [Intel 8253-compatible PIT](/include/kernaux/drivers/intel_8253_pit.h) (*work in progress*)
+  * [Intel 8259-compatible PIC](/include/kernaux/drivers/intel_8259_pic.h) (*work in progress*)
   * USB (*planned*)
 
 ### Definitions

include/Makefile.am

@@ -27,17 +27,6 @@ if ASM_X86_64
 nobase_include_HEADERS += kernaux/asm/x86_64.h
 endif
 
-###########
-# Drivers #
-###########
-
-if WITH_DRIVERS
-nobase_include_HEADERS += \
-	kernaux/drivers/console.h \
-	kernaux/drivers/framebuffer.h \
-	kernaux/drivers/intel_8259_pic.h
-endif
-
 ####################
 # Default packages #
 ####################
@@ -78,3 +67,26 @@ endif
 if WITH_UNITS
 nobase_include_HEADERS += kernaux/units.h
 endif
+
+###########
+# Drivers #
+###########
+
+if WITH_DRIVERS
+nobase_include_HEADERS += \
+	kernaux/drivers/console.h \
+	kernaux/drivers/framebuffer.h
+
+# Intel 8253-compatible programmable interval timer
+
+if ASM_I386
+nobase_include_HEADERS += kernaux/drivers/intel_8253_pit.h
+endif
+
+# Intel 8259-compatible programmable interrupt controller
+
+if ASM_I386
+nobase_include_HEADERS += kernaux/drivers/intel_8259_pic.h
+endif
+
+endif # WITH_DRIVERS

include/kernaux/drivers/intel_8253_pit.h

@@ -0,0 +1,21 @@
+/**
+ * @brief A driver for Intel 8253-compatible programmable interval timer
+ *
+ * @see https://en.wikipedia.org/wiki/Intel_8253
+ * @see https://wiki.osdev.org/PIT
+ */
+
+#ifndef KERNAUX_INCLUDED_DRIVERS_INTEL_8253_PIT
+#define KERNAUX_INCLUDED_DRIVERS_INTEL_8253_PIT
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void kernaux_drivers_intel_8253_pit_initialize(unsigned int freq);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

src/drivers/intel_8253_pit.c

@@ -0,0 +1,31 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <kernaux/assert.h>
+#include <kernaux/drivers/intel_8253_pit.h>
+
+#ifdef ASM_I386
+#include <kernaux/asm/i386.h>
+#endif
+
+#include <stdint.h>
+
+#if defined(ASM_I386)
+#   define inportb  kernaux_asm_i386_inportb
+#   define outportb kernaux_asm_i386_outportb
+#endif
+
+void kernaux_drivers_intel_8253_pit_initialize(const unsigned int freq)
+{
+    KERNAUX_ASSERT(freq);
+
+    const unsigned int divisor = 1193180 / freq;
+
+    const uint8_t l = divisor & 0xff;
+    const uint8_t h = (divisor >> 8) & 0xff;
+
+    outportb(0x43, 0x36);
+    outportb(0x40, l);
+    outportb(0x40, h);
+}

src/drivers/intel_8259_pic.c

@@ -21,10 +21,7 @@
 #define IRQS_COUNT 8
 #define IRQS_TOTAL 16
 
-#undef AVAILABLE
+#if defined(ASM_I386)
-#define NOT_AVAILABLE_MSG "Intel 8259-compatible PIC is not available"
-#ifdef ASM_I386
-#   define AVAILABLE
 #   define inportb  kernaux_asm_i386_inportb
 #   define outportb kernaux_asm_i386_outportb
 #endif
@@ -34,30 +31,18 @@ static unsigned char slave_start  = 8;
 
 void kernaux_drivers_intel_8259_pic_enable_all()
 {
-#ifndef AVAILABLE
-    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
-#else
     outportb(MASTER_DATA_PORT, 0);
     outportb(SLAVE_DATA_PORT,  0);
-#endif
 }
 
 void kernaux_drivers_intel_8259_pic_disable_all()
 {
-#ifndef AVAILABLE
-    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
-#else
     outportb(MASTER_DATA_PORT, 0xFF);
     outportb(SLAVE_DATA_PORT,  0xFF);
-#endif
 }
 
 void kernaux_drivers_intel_8259_pic_enable(const unsigned char number)
 {
-#ifndef AVAILABLE
-    (void)number;
-    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
-#else
     KERNAUX_ASSERT(number < IRQS_TOTAL);
 
     if (number < IRQS_COUNT) {
@@ -67,15 +52,10 @@ void kernaux_drivers_intel_8259_pic_enable(const unsigned char number)
         const uint8_t mask = inportb(SLAVE_DATA_PORT);
         outportb(SLAVE_DATA_PORT, mask & ~(1 << (number - IRQS_COUNT)));
     }
-#endif
 }
 
 void kernaux_drivers_intel_8259_pic_disable(const unsigned char number)
 {
-#ifndef AVAILABLE
-    (void)number;
-    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
-#else
     KERNAUX_ASSERT(number < IRQS_TOTAL);
 
     if (number < IRQS_COUNT) {
@@ -85,16 +65,12 @@ void kernaux_drivers_intel_8259_pic_disable(const unsigned char number)
         const uint8_t mask = inportb(SLAVE_DATA_PORT);
         outportb(SLAVE_DATA_PORT, mask | (1 << (number - IRQS_COUNT)));
     }
-#endif
 }
 
 void kernaux_drivers_intel_8259_pic_remap(
     const unsigned char new_master_start,
     const unsigned char new_slave_start
 ) {
-#ifndef AVAILABLE
-    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
-#else
     master_start = new_master_start;
     slave_start  = new_slave_start;
 
@@ -121,14 +97,10 @@ void kernaux_drivers_intel_8259_pic_remap(
     // Restore masks
     outportb(MASTER_DATA_PORT, master_mask);
     outportb(SLAVE_DATA_PORT,  slave_mask);
-#endif
 }
 
 void kernaux_drivers_intel_8259_pic_eoi(const unsigned char number)
 {
-#ifndef AVAILABLE
-    KERNAUX_PANIC(NOT_AVAILABLE_MSG);
-#else
     KERNAUX_ASSERT(number < IRQS_TOTAL);
 
     const bool to_slave =
@@ -138,5 +110,4 @@ void kernaux_drivers_intel_8259_pic_eoi(const unsigned char number)
 
     if (to_slave)  outportb(SLAVE_COMMAND_PORT,  0x20);
     if (to_master) outportb(MASTER_COMMAND_PORT, 0x20);
-#endif
 }