Brightness control for pi-top.

MiSTer.vcxproj

@@ -40,6 +40,7 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="archie.c" />
+    <ClCompile Include="brightness.c" />
     <ClCompile Include="cfg.c" />
     <ClCompile Include="DiskImage.cpp" />
     <ClCompile Include="file_io.c" />
@@ -63,6 +64,7 @@
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="archie.h" />
+    <ClInclude Include="brightness.h" />
     <ClInclude Include="cfg.h" />
     <ClInclude Include="charrom.h" />
     <ClInclude Include="debug.h" />

MiSTer.vcxproj.filters

@@ -74,6 +74,9 @@
     <ClCompile Include="st_tos.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="brightness.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="archie.h">
@@ -163,6 +166,9 @@
     <ClInclude Include="st_tos.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="brightness.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="build.sh" />

brightness.c

@@ -0,0 +1,252 @@
+/*
+ * brightness.c
+ * 
+ * Copyright 2016  rricharz
+ * MiSTer port. Copyright 2018 Sorgelig
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ * 
+ * 
+ */
+
+#include <stdint.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <linux/types.h>
+#include <linux/spi/spidev.h>
+#include "brightness.h"
+
+#define MAXCOUNT 10		// maximum number of spi transfer attemps
+
+#define LIDBITMASK		0x04
+#define	SCREENOFFMASK	0x02
+#define PARITYMASK		0x80
+#define BRIGHTNESSMASK  0x78
+#define SHUTDOWNMASK	0X01
+
+///////////////////////////////////////////////////
+
+static uint32_t    spiSpeed;
+static int         spiFd = -1;
+
+static const uint8_t  spiBPW   = 8;
+static const uint16_t spiDelay = 0;
+
+static int spi_rw(unsigned char *data, int len)
+{
+	struct spi_ioc_transfer spi;
+
+	memset (&spi, 0, sizeof (spi));
+
+	spi.tx_buf        = (unsigned long)data;
+	spi.rx_buf        = (unsigned long)data;
+	spi.len           = len;
+	spi.delay_usecs   = spiDelay;
+	spi.speed_hz      = spiSpeed;
+	spi.bits_per_word = spiBPW;
+
+	return ioctl (spiFd, SPI_IOC_MESSAGE(1), &spi);
+}
+
+static int spi_open(int speed, int mode)
+{
+	int fd ;
+	mode &= 3;	// Mode is 0, 1, 2 or 3
+
+	if ((fd = open ("/dev/spidev32766.0", O_RDWR)) < 0)
+	{
+		printf("Unable to open SPI device: %s\n", strerror (errno));
+		return -1;
+	}
+
+	if (ioctl (fd, SPI_IOC_WR_MODE, &mode) >= 0)
+	{
+		if (ioctl (fd, SPI_IOC_WR_BITS_PER_WORD, &spiBPW) >= 0)
+		{
+			if (ioctl (fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed) >= 0)
+			{
+				spiSpeed = speed;
+				spiFd    = fd;
+				return fd;
+			}
+			else
+			{
+				printf ("SPI Speed Change failure: %s\n", strerror (errno));
+			}
+		}
+		else
+		{
+			printf ("SPI BPW Change failure: %s\n", strerror (errno));
+		}
+	}
+	else
+	{
+		printf ("SPI Mode Change failure: %s\n", strerror (errno));
+	}
+
+	close(fd);
+	fd = -1;
+	return -1;
+}
+
+static int spi_close()
+{
+	if(spiFd >= 0) close(spiFd);
+	spiFd = -1;
+}
+
+///////////////////////////////////////////////////
+
+static int lidbit;
+static int screenoffbit;
+static int parity;
+static int brightness = 6;
+static int shutdown;
+
+//////////////////////////////
+// Calclate the parity of bits 0 - 6
+static int parity7(unsigned char data)
+{
+	int i;
+	int p = 0;
+	for (i = 0; i < 7; i++) {
+		if (data & 1) p = !p;
+		data = data >> 1;
+	}
+	return p;
+}
+
+///////////////////////////////
+// analyze data byte and set global variables
+// return 1 of parity is ok
+// Sending: bit 8 = parity of bit 1-7
+static int analyze(unsigned char data)
+{
+	lidbit			= (data & LIDBITMASK) != 0;
+	screenoffbit	= (data & SCREENOFFMASK) != 0;
+	parity			= (data & PARITYMASK) != 0;
+	brightness		= (data & BRIGHTNESSMASK) >> 3;
+	shutdown		= (data & SHUTDOWNMASK) != 0;
+
+	// printf("lid = %d, screen = %d, parity = %d, shutdown = %d, brightness = %d\n", lidbit, screenoffbit, parity, shutdown, brightness);
+
+	return (parity7(data) == parity);
+}
+
+///////////////
+// Calculate data byte using global variables
+// Set brightness and status parity bits
+// Receiving: bit 8 = brightness parity, bit 3 = status parity
+static int calculate()
+{
+	int data = brightness << 3;
+	if (parity7(brightness)) data += PARITYMASK;
+	if (shutdown) data += SHUTDOWNMASK;
+	if (screenoffbit) data += SCREENOFFMASK;
+	if (parity7(data & 3)) data += LIDBITMASK;		// parity ofthe two state bits
+	return data;		
+}
+
+void setBrightness(int cmd, int val)
+{
+	unsigned char data, new_data;
+	int count, ok;
+
+	if (spi_open(9600, 0) < 0)
+	{
+		printf("Cannot initialize spi driver\n");
+		return;
+	}
+
+	// send 0xFF and receive current status of pi-top-hub
+	count = 0;
+	data = 0xff;
+	printf("Brighntess sending: 0x%X\n", data);
+	do
+	{
+		data = 0xff;
+		ok = spi_rw(&data, 1);
+		if (ok) ok = analyze(data);
+	}
+	while ((!ok) && (count++ < MAXCOUNT));
+	// printf("count = %d\n", count);
+
+	if (ok)
+	{
+		printf("Brighntess receiving: 0x%X - ", data);
+		printf("Current brightness = %d, ", brightness);
+		//force to 0 as set to 1 if rebooted while in screenbitoff=0
+		//the state is stored on pi-top-hub, but isn't reinitialised on reboot
+		screenoffbit=0;
+		if(cmd == BRIGHTNESS_UP) 
+		{
+			brightness++;
+		}
+		else if (cmd == BRIGHTNESS_DOWN)
+		{
+			brightness--;
+		}
+		else if (cmd == BRIGHTNESS_SET)
+		{
+			if(!val) screenoffbit=1;
+			else screenoffbit = 0;
+			brightness = val;
+		}
+
+		if (brightness < 1) brightness = 1;
+		if (brightness > 10) brightness = 10;
+
+		printf("Requested brightness = %d, ", brightness);
+        printf("Requested off = %d\n", screenoffbit);
+
+		// calculate data to send
+		shutdown = 0;		
+		new_data = calculate();
+
+		// send new data until accepted
+		count = 0;
+		data = new_data;
+		printf("Brighntess sending: 0x%X\n", data);
+		do
+		{
+			data = new_data;
+			ok = spi_rw(&data, 1);
+			if (ok) ok = (data & BRIGHTNESSMASK) == (new_data & BRIGHTNESSMASK);
+		}
+		while ((!ok) && (count++ < MAXCOUNT));
+
+		// printf("count = %d\n", count);
+		if (ok)
+		{
+			printf("Brighntess receiving: 0x%X - ", data);
+			printf("New brightness = %d\n", brightness);
+		}
+	}
+	else printf("Reading current brightness not successful\n");
+
+	spi_close();
+}
+
+int getBrightness()
+{
+	if (screenoffbit) return 0;
+	return brightness;
+}

brightness.h

@@ -0,0 +1,11 @@
+#ifndef __BRIGHTNESS_H__
+#define __BRIGHTNESS_H__
+
+#define BRIGHTNESS_SET  0
+#define BRIGHTNESS_UP   1
+#define BRIGHTNESS_DOWN 2
+
+void setBrightness(int cmd, int val);
+int getBrightness();
+
+#endif

user_io.c

@@ -26,6 +26,7 @@
 #include "minimig_boot.h"
 #include "minimig_fdd.h"
 #include "minimig_hdd.h"
+#include "brightness.h"
 
 #define BREAK  0x8000
 
@@ -1850,6 +1851,24 @@ void user_io_kbd(uint16_t key, int press)
 		}
 	}
 	else
+	if (key == 0xBE)
+	{
+		if (press)
+		{
+			setBrightness(BRIGHTNESS_DOWN, 0);
+			vol_set_timeout = GetTimer(1000);
+		}
+	}
+	else
+	if (key == 0xBF)
+	{
+		if (press)
+		{
+			setBrightness(BRIGHTNESS_UP, 0);
+			vol_set_timeout = GetTimer(1000);
+		}
+	}
+	else
 	if ((core_type == CORE_TYPE_MINIMIG2) ||
 		(core_type == CORE_TYPE_MIST) ||
 		(core_type == CORE_TYPE_ARCHIE) ||