From f61216414a9e2d00c7b7afaaedb498574f6f805a Mon Sep 17 00:00:00 2001
From: Francis Rowe <info@gluglug.org.uk>
Date: Wed, 11 Feb 2015 11:30:38 -0500
Subject: i945-pwm: add -lz to Makefile

Fixes build error reported by user.
---
(limited to 'resources/utilities/i945-pwm/i945-pwm.c')

diff --git a/resources/utilities/i945-pwm/i945-pwm.c b/resources/utilities/i945-pwm/i945-pwm.c
new file mode 100644
index 0000000..e3dc574
--- /dev/null
+++ b/resources/utilities/i945-pwm/i945-pwm.c
@@ -0,0 +1,163 @@
+/*
+  Copyright (C) 2014  Michał Masłowski  <mtjm@mtjm.eu>
+
+  This program 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 Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* Try several backlight PWM frequencies and duty cycles to see which
+   expose the noise on X60 with coreboot.
+*/
+
+#include <assert.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <pci/pci.h>
+
+static struct pci_access *pacc;
+static uint32_t *map;
+static int fd;
+
+#define REGISTER 0x61254
+
+static void
+init (void)
+{
+  fd = -1;
+  /* Find the device. */
+  struct pci_dev *dev;
+  pacc = pci_alloc ();
+  pacc->writeable = 1;
+  pci_init (pacc);
+  pci_scan_bus (pacc);
+  for (dev = pacc->devices; dev != NULL; dev = dev->next)
+    {
+      pci_fill_info (dev, PCI_FILL_IDENT | PCI_FILL_BASES);
+      if (dev->vendor_id != 0x8086 || dev->device_id != 0x27a2)
+        continue;
+      break;
+    }
+  if (dev == NULL)
+    {
+      fprintf (stderr, "Device not found.\n");
+      goto fail;
+    }
+  /* Map a part of its MMIO. */
+  fd = open ("/dev/mem", O_RDWR);
+  if (fd == -1)
+    {
+      fprintf (stderr, "Cannot open memory.  Are you root?\n");
+      goto fail;
+    }
+  map = mmap (NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED, fd, dev->base_addr[0] + (REGISTER & (~4095)));
+  if (map != MAP_FAILED)
+    return;
+  else
+    perror ("mmap failed");
+ fail:
+  if (pacc != NULL)
+    pci_cleanup (pacc);
+  if (fd != -1)
+    close (fd);
+  exit (1);
+}
+
+static void
+set_pwm (uint16_t freq, uint16_t duty)
+{
+  assert (duty <= freq);
+  map[((REGISTER - 4) & 4095) >> 2] = 0x80000000;
+  map[(REGISTER & 4095) >> 2] = ((freq | 1) << 16) | duty;
+}
+
+int
+main (void)
+{
+  init ();
+  int exponent = 8;
+  int diff = 0;
+  int divisor = 2;
+  uint16_t freq = 0x61;
+  uint16_t duties[] = {
+#if 1
+    // i945
+    0xf,
+    0x13,
+    0x19,
+    0x1f,
+    0x23,
+    0x29,
+    0x2f,
+    0x35,
+    0x39,
+    0x3f,
+    0x45,
+    0x4b,
+    0x4f,
+    0x55,
+    0x5b,
+    0x61
+#else
+    // gm45
+    0x2,
+    0x4,
+    0x5,
+    0x7,
+    0x9,
+    0xb,
+    0xd,
+    0x11,
+    0x14,
+    0x17,
+    0x1c,
+    0x20,
+    0x27,
+    0x31,
+    0x41,
+    0x61,
+#endif
+  };
+#if 1
+  for (unsigned int di = 0; di < sizeof (duties) / sizeof (duties[0]); di++)
+    {
+      uint16_t duty = duties[di];
+#else
+      for (uint16_t duty = 0; duty < 0x61; duty++)
+        {
+#endif
+#if 0
+        }
+#endif
+      uint16_t pwm_freq = (freq + diff) << exponent;
+      pwm_freq += (pwm_freq >> divisor);
+      //pwm_freq |= 0x33;
+      uint16_t pwm_duty = (duty + diff) << exponent;
+      pwm_duty += (pwm_duty >> divisor);
+      //pwm_duty |= 0x32;
+      set_pwm (pwm_freq, pwm_duty);
+      sleep (1);
+    }
+  if (pacc != NULL)
+    pci_cleanup (pacc);
+  if (map != NULL)
+    munmap (map, 4096);
+  if (fd != -1)
+    close (fd);
+  return 0;
+}
--
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