kernel: ps2 mouse support

2 files changed, 90 insertions, 23 deletions

diff --git a/src/kernel/arch/amd64/driver/ps2.c b/src/kernel/arch/amd64/driver/ps2.c
index 7ed369b..1ddd27a 100644
--- a/src/kernel/arch/amd64/driver/ps2.c
+++ b/src/kernel/arch/amd64/driver/ps2.c
@@ -7,31 +7,106 @@
 #include <kernel/vfs/request.h>
 #include <shared/mem.h>
 
-static volatile uint8_t backlog_buf[64];
-static volatile ring_t backlog = {(void*)backlog_buf, sizeof backlog_buf, 0, 0};
+static const int PS2 = 0x60;
+
+static volatile uint8_t kb_buf[64];
+static volatile ring_t kb_backlog = {(void*)kb_buf, sizeof kb_buf, 0, 0};
+
+static volatile uint8_t mouse_buf[64];
+static volatile ring_t mouse_backlog = {(void*)mouse_buf, sizeof mouse_buf, 0, 0};
 
 static void accept(struct vfs_request *req);
 static bool is_ready(struct vfs_backend *self);
 
 static struct vfs_request *kb_queue = NULL;
+static struct vfs_request *mouse_queue = NULL;
 static struct vfs_backend backend = BACKEND_KERN(is_ready, accept);
-void ps2_init(void) { vfs_mount_root_register("/ps2", &backend); }
 
+static void wait_out(void) {
+	uint8_t status;
+	do {
+		status = port_in8(PS2 + 4);
+	} while (status & 2);
+}
+
+static void wait_in(void) {
+	uint8_t status;
+	do {
+		status = port_in8(PS2 + 4);
+	} while (!(status & 1));
+}
+
+void ps2_init(void) {
+	vfs_mount_root_register("/ps2", &backend);
+
+	uint8_t compaq, ack;
+	wait_out();
+	port_out8(PS2 + 4, 0x20); /* get compaq status */
+
+	wait_in();
+	compaq = port_in8(PS2);
+	compaq |= 1 << 1; /* enable IRQ12 */
+	compaq &= ~(1 << 5); /* enable mouse clock */
+
+	wait_out();
+	port_out8(PS2 + 4, 0x60); /* set compaq status */
+
+	wait_out();
+	port_out8(PS2, compaq);
+
+	wait_out();
+	port_out8(PS2 + 4, 0xD4);
+	wait_out();
+	port_out8(PS2, 0xF4); /* packet streaming */
+	wait_in();
+	ack = port_in8(PS2);
+	assert(ack == 0xFA);
+}
 
 void ps2_irq(void) {
-	ring_put1b((void*)&backlog, port_in8(0x60));
-	if (kb_queue) {
-		accept(kb_queue);
-		kb_queue = kb_queue->postqueue_next;
-		vfs_backend_tryaccept(&backend);
+	for (;;) {
+		uint64_t status = port_in8(PS2 + 4);
+		if (!(status & 1)) break; /* read while data available */
+		if (status & (1 << 5)) {
+			ring_put1b((void*)&mouse_backlog, port_in8(PS2));
+			if (mouse_queue) {
+				accept(mouse_queue);
+				mouse_queue = mouse_queue->postqueue_next;
+				vfs_backend_tryaccept(&backend);
+			}
+		} else {
+			ring_put1b((void*)&kb_backlog, port_in8(PS2));
+			if (kb_queue) {
+				accept(kb_queue);
+				kb_queue = kb_queue->postqueue_next;
+				vfs_backend_tryaccept(&backend);
+			}
+		}
 	}
 }
 
 enum {
 	H_ROOT,
 	H_KB,
+	H_MOUSE,
 };
 
+static void read_backlog(struct vfs_request *req, ring_t *r, struct vfs_request **queue) {
+	if (ring_size(r) == 0) {
+		/* nothing to read, join queue */
+		assert(!req->postqueue_next);
+		while (*queue) queue = &(*queue)->postqueue_next;
+		*queue = req;
+	} else if (req->caller) {
+		int len = req->output.len;
+		if (len < 0) len = 0;
+		len = ring_to_virt(r, req->caller->pages, req->output.buf, len);
+		vfsreq_finish_short(req, len);
+	} else {
+		vfsreq_finish_short(req, -1);
+	}
+}
+
 static void accept(struct vfs_request *req) {
 	// when you fix something here go also fix it in the COM1 driver
 	int ret;
@@ -42,29 +117,21 @@ static void accept(struct vfs_request *req) {
 				vfsreq_finish_short(req, H_ROOT);
 			} else if (req->input.len == 3 && !memcmp(req->input.buf_kern, "/kb", 3)) {
 				vfsreq_finish_short(req, H_KB);
+			} else if (req->input.len == 6 && !memcmp(req->input.buf_kern, "/mouse", 6)) {
+				vfsreq_finish_short(req, H_MOUSE);
 			} else {
 				vfsreq_finish_short(req, -1);
 			}
 			break;
 		case VFSOP_READ:
 			if ((long __force)req->id == H_ROOT) {
-				const char data[] = "kb";
+				const char data[] = "kb\0mouse";
 				ret = req_readcopy(req, data, sizeof data);
 				vfsreq_finish_short(req, ret);
 			} else if ((long __force)req->id == H_KB) {
-				if (ring_size((void*)&backlog) == 0) {
-					/* nothing to read, join queue */
-					assert(!req->postqueue_next);
-					struct vfs_request **slot = &kb_queue;
-					while (*slot) slot = &(*slot)->postqueue_next;
-					*slot = req;
-				} else if (req->caller) {
-					if (ret < 0) ret = 0;
-					ret = ring_to_virt((void*)&backlog, req->caller->pages, req->output.buf, req->output.len);
-					vfsreq_finish_short(req, ret);
-				} else {
-					vfsreq_finish_short(req, -1);
-				}
+				read_backlog(req, (void*)&kb_backlog, &kb_queue);
+			} else if ((long __force)req->id == H_MOUSE) {
+				read_backlog(req, (void*)&mouse_backlog, &mouse_queue);
 			} else panic_invalid_state();
 			break;
 		default:
diff --git a/src/kernel/arch/amd64/driver/serial.c b/src/kernel/arch/amd64/driver/serial.c
index d8ee90b..921e140 100644
--- a/src/kernel/arch/amd64/driver/serial.c
+++ b/src/kernel/arch/amd64/driver/serial.c
@@ -80,8 +80,8 @@ static void accept(struct vfs_request *req) {
 				while (*slot) slot = &(*slot)->postqueue_next;
 				*slot = req;
 			} else if (req->caller) {
-				if (ret < 0) ret = 0;
 				ret = ring_to_virt((void*)&backlog, req->caller->pages, req->output.buf, req->output.len);
+				// TODO output.len can overflow here
 				vfsreq_finish_short(req, ret);
 			} else {
 				vfsreq_finish_short(req, -1);