Add parallel port joypad driver

Makefile

@@ -121,6 +121,11 @@ $(OBJDIR)/tools/linuxraw_joypad.o: input/linuxraw_joypad.c
 	@$(if $(Q), $(shell echo echo CC $<),)
 	$(Q)$(CC) $(CFLAGS) $(DEFINES) -MMD -DIS_JOYCONFIG -c -o $@ $<
 
+$(OBJDIR)/tools/parport_joypad.o: input/parport_joypad.c
+	@mkdir -p $(dir $@)
+	@$(if $(Q), $(shell echo echo CC $<),)
+	$(Q)$(CC) $(CFLAGS) $(DEFINES) -MMD -DIS_JOYCONFIG -c -o $@ $<
+
 $(OBJDIR)/tools/udev_joypad.o: input/udev_joypad.c
 	@mkdir -p $(dir $@)
 	@$(if $(Q), $(shell echo echo CC $<),)

Makefile.common

@@ -59,8 +59,8 @@ endif
 ifneq ($(findstring Linux,$(OS)),)
    LIBS += -lrt
    JOYCONFIG_LIBS += -lrt
-   OBJ += input/linuxraw_input.o input/linuxraw_joypad.o
-   JOYCONFIG_OBJ += tools/linuxraw_joypad.o
+   OBJ += input/linuxraw_input.o input/linuxraw_joypad.o input/parport_joypad.o
+   JOYCONFIG_OBJ += tools/linuxraw_joypad.o tools/parport_joypad.o
 endif
 
 ifeq ($(findstring Haiku,$(OS)),)

input/input_common.c

@@ -75,6 +75,7 @@ rarch_joypad_driver_t *joypad_drivers[] = {
 #endif
 #if defined(__linux) && !defined(ANDROID)
    &linuxraw_joypad,
+   &parport_joypad,
 #endif
 #ifdef ANDROID
    &android_joypad,

input/input_common.h

@@ -127,6 +127,7 @@ const char *input_joypad_name(const rarch_joypad_driver_t *driver,
 
 extern rarch_joypad_driver_t dinput_joypad;
 extern rarch_joypad_driver_t linuxraw_joypad;
+extern rarch_joypad_driver_t parport_joypad;
 extern rarch_joypad_driver_t udev_joypad;
 extern rarch_joypad_driver_t winxinput_joypad;
 extern rarch_joypad_driver_t sdl_joypad;

input/parport_joypad.c

@@ -0,0 +1,244 @@
+/*  RetroArch - A frontend for libretro.
+ *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
+ *  Copyright (C) 2014 - Mike Robinson
+ *
+ *  RetroArch is free software: you can redistribute it and/or modify it under the terms
+ *  of the GNU General Public License as published by the Free Software Found-
+ *  ation, either version 3 of the License, or (at your option) any later version.
+ *
+ *  RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ *  PURPOSE.  See the GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with RetroArch.
+ *  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "input_common.h"
+#include "../general.h"
+#include <unistd.h>
+#include <stdint.h>
+#include <string.h>
+#include <limits.h>
+#include <errno.h>
+#include <linux/parport.h>
+#include <linux/ppdev.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+
+/* Linux parport driver does not support reading the control register
+   Other platforms may support up to 17 buttons */
+#define NUM_BUTTONS 13
+
+struct parport_joypad
+{
+   int fd;
+   bool buttons[NUM_BUTTONS];
+
+   char *ident;
+};
+
+static struct parport_joypad g_pads[MAX_PLAYERS];
+
+static void poll_pad(struct parport_joypad *pad)
+{
+   /* RetroArch uses an extended version of the Linux
+   * Multisystem 2-button joystick protocol for parallel port
+   * joypads:
+   *
+   * | Function    | Pin | Register | Bit | Active |
+   * |-------------|-----|----------|-----|--------|
+   * | Up          | 2   | Data     | 0   | Low    |
+   * | Down        | 3   | Data     | 1   | Low    |
+   * | Left        | 4   | Data     | 2   | Low    |
+   * | Right       | 5   | Data     | 3   | Low    |
+   * | A           | 6   | Data     | 4   | Low    |
+   * | B           | 7   | Data     | 5   | Low    |
+   * | Start       | 8   | Data     | 6   | Low    |
+   * | Select      | 9   | Data     | 7   | Low    |
+   * | Menu toggle | 10  | Status   | 6   | Low    |
+   * | X           | 11  | Status   | 7   | Low*   |
+   * | Y           | 12  | Status   | 5   | Low    |
+   * | L1          | 13  | Status   | 4   | Low    |
+   * | R1          | 15  | Status   | 3   | Low    |
+   *
+   * (*) Pin is hardware inverted, but RetroArch inverts it
+   *     back again so the same pullup scheme may be used for
+   *     all pins.
+   *
+   * RetroArch does not perform debouncing, and so long as
+   * the button settling time is less than the frame time
+   * no bouncing will be observed. This replicates the latching
+   * behavior common in old games consoles. For optimum latency
+   * and jitter a high performance debouncing routine should be
+   * implemented in the controller hardware.
+   */
+
+   int i;
+   char data;
+   char status;
+
+   ioctl(pad->fd, PPRDATA, &data);
+   ioctl(pad->fd, PPRSTATUS, &status);
+
+   for (i = 0; i < 8; i++)
+   {
+      pad->buttons[i] = !(data & UINT8_C(1 << i));
+   }
+   for (i = 3; i < 8; i++)
+   {
+      pad->buttons[i + 5] = !(status & UINT8_C(1 << i));
+   }
+   pad->buttons[12] = pad->buttons[12] ? false : true;
+}
+
+static bool parport_joypad_init_pad(const char *path, struct parport_joypad *pad)
+{
+   int datadir = 1; /* read */
+   char data;
+   bool irq_disable = false;
+   int mode = IEEE1284_MODE_BYTE;
+
+   if (pad->fd >= 0)
+      return false;
+
+   if (access(path, R_OK | W_OK) < 0)
+      return false;
+
+   pad->fd = open(path, O_RDWR);
+
+   *pad->ident = '\0';
+   if (pad->fd >= 0)
+   {
+      RARCH_LOG("[Joypad]: Found parallel port: %s\n", path);
+
+      /* Parport driver does not log failures with RARCH_ERR because they could be
+       * a normal result of connected non-joypad devices. */
+      if (ioctl(pad->fd, PPCLAIM) < 0)
+      {
+         RARCH_WARN("[Joypad]: Failed to claim %s\n", path);
+         goto error;
+      }
+      if (ioctl(pad->fd, PPSETMODE, &mode) < 0)
+      {
+         RARCH_WARN("[Joypad]: Failed to set byte mode on %s\n", path);
+         goto error;
+      }
+      if (ioctl(pad->fd, PPDATADIR, &datadir) < 0)
+      {
+         RARCH_WARN("[Joypad]: Failed to set data direction to input on %s\n", path);
+         goto error;
+      }
+      if (ioctl(pad->fd, PPRCONTROL, &data) == 0)
+      {
+         data &= 0xEF; /* Clear bit 4 to disable interrupts */
+         if (ioctl(pad->fd, PPWCONTROL, &data) == 0)
+            irq_disable = true;
+      }
+      /* Failure to disable interrupts only slightly increases CPU use, not an error */
+      if (!irq_disable)
+         RARCH_WARN("[Joypad]: Failed to disable interrupts on %s\n", path);
+
+      strlcpy(pad->ident, "Parallel port device", sizeof(g_settings.input.device_names[0]));
+      return true;
+error:
+      close(pad->fd);
+      pad->fd = 0;
+      return false;
+   }
+
+   RARCH_WARN("[Joypad]: Failed to open parallel port %s (error: %s).\n", path, strerror(errno));
+   return false;
+}
+
+static void parport_joypad_poll(void)
+{
+   int i;
+
+   for (i = 0; i < MAX_PLAYERS; i++)
+   {
+      if (g_pads[i].fd >= 0)
+      {
+         poll_pad(&g_pads[i]);
+      }
+   }
+}
+
+static bool parport_joypad_init(void)
+{
+   unsigned i;
+
+   for (i = 0; i < MAX_PLAYERS; i++)
+   {
+      struct parport_joypad *pad = &g_pads[i];
+      pad->fd = -1;
+      pad->ident = g_settings.input.device_names[i];
+
+      char path[PATH_MAX];
+      snprintf(path, sizeof(path), "/dev/parport%u", i);
+
+      if (parport_joypad_init_pad(path, pad))
+          {
+             input_config_autoconfigure_joypad(i, pad->ident, 0, 0, "parport");
+             poll_pad(pad);
+          }
+          else
+             input_config_autoconfigure_joypad(i, NULL, 0, 0, NULL);
+       }
+
+   return true;
+}
+
+static void parport_joypad_destroy(void)
+{
+   unsigned i;
+   for (i = 0; i < MAX_PLAYERS; i++)
+   {
+      if (g_pads[i].fd >= 0)
+      {
+         ioctl(g_pads[i].fd, PPRELEASE);
+         close(g_pads[i].fd);
+      }
+   }
+   memset(g_pads, 0, sizeof(g_pads));
+   for (i = 0; i < MAX_PLAYERS; i++)
+      g_pads[i].fd = -1;
+}
+
+static bool parport_joypad_button(unsigned port, uint16_t joykey)
+{
+   const struct parport_joypad *pad = &g_pads[port];
+
+   return joykey < NUM_BUTTONS && pad->buttons[joykey];
+}
+
+static int16_t parport_joypad_axis(unsigned port, uint32_t joyaxis)
+{
+   /* Parport does not support analog sticks */
+   return 0;
+}
+
+static bool parport_joypad_query_pad(unsigned pad)
+{
+   return pad < MAX_PLAYERS && g_pads[pad].fd >= 0;
+}
+
+static const char *parport_joypad_name(unsigned pad)
+{
+   if (pad >= MAX_PLAYERS)
+      return NULL;
+
+   return *g_pads[pad].ident ? g_pads[pad].ident : NULL;
+}
+
+rarch_joypad_driver_t parport_joypad = {
+   parport_joypad_init,
+   parport_joypad_query_pad,
+   parport_joypad_destroy,
+   parport_joypad_button,
+   parport_joypad_axis,
+   parport_joypad_poll,
+   NULL,
+   parport_joypad_name,
+   "parport",
+};