diff options
Diffstat (limited to 'drv_generic_i2c.c')
| -rw-r--r-- | drv_generic_i2c.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/drv_generic_i2c.c b/drv_generic_i2c.c new file mode 100644 index 0000000..3d99c2d --- /dev/null +++ b/drv_generic_i2c.c @@ -0,0 +1,173 @@ +/* $Id: drv_generic_i2c.c 771 2007-02-25 12:27:26Z michael $ + * $URL: https://ssl.bulix.org/svn/lcd4linux/trunk/drv_generic_i2c.c $ + * + * generic driver helper for i2c displays + * + * Copyright (C) 2005 Luis Correia <lfcorreia@users.sf.net> + * Copyright (C) 2005 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net> + * + * This file is part of LCD4Linux. + * + * LCD4Linux 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, or (at your option) + * any later version. + * + * LCD4Linux 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., 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + + /* + DISCLAIMER!!!! + + The following code is WORK IN PROGRESS, since it basicly 'works for us...' + + (C) 2005 Paul Kamphuis & Luis Correia + + We have removed all of the delays from this code, as the I2C bus is slow enough... + (maximum possible speed is 100KHz only) + + */ + +#include "config.h" + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <termios.h> +#include <fcntl.h> +#include <time.h> +#include <signal.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/ioctl.h> + +#include "lcd4linux_i2c.h" +#include "debug.h" +#include "qprintf.h" +#include "cfg.h" +#include "udelay.h" +#include "drv_generic_i2c.h" + + +static char *Driver = ""; +static char *Section = ""; +static int i2c_device; + + +static void my_i2c_smbus_write_byte_data(const int device, const unsigned char val) +{ + struct i2c_smbus_ioctl_data args; + union i2c_smbus_data data; + args.read_write = I2C_SMBUS_WRITE; + args.command = val; + args.size = I2C_SMBUS_BYTE_DATA; + data.byte = val; + args.data = &data; + if (ioctl(device, I2C_SMBUS, &args) < 0) { + info("I2C: device %d IOCTL failed !\n", device); + } +} + +/* unused, ifdef'ed away to avoid compiler warning */ +#if 0 +static void my_i2c_smbus_read_byte_data(const int device, const unsigned char data) +{ + struct i2c_smbus_ioctl_data args; + args.read_write = I2C_SMBUS_READ; + args.command = data; + args.size = I2C_SMBUS_BYTE; + args.data = 0; + ioctl(device, I2C_SMBUS, &args); +} +#endif + + +int drv_generic_i2c_open(const char *section, const char *driver) +{ + int dev; + char *bus, *device; + udelay_init(); + Section = (char *) section; + Driver = (char *) driver; + bus = cfg_get(Section, "Port", NULL); + device = cfg_get(Section, "Device", NULL); + dev = atoi(device); + info("%s: initializing I2C bus %s", Driver, bus); + if ((i2c_device = open(bus, O_WRONLY)) < 0) { + error("%s: I2C bus %s open failed !\n", Driver, bus); + goto exit_error; + } + info("%s: selecting slave device 0x%x", Driver, dev); + if (ioctl(i2c_device, I2C_SLAVE, dev) < 0) { + error("%s: error selecting slave device 0x%x\n", Driver, dev); + goto exit_error; + } + + info("%s: initializing I2C slave device 0x%x", Driver, dev); + if (i2c_smbus_write_quick(i2c_device, I2C_SMBUS_WRITE) < 0) { + error("%s: error initializing device 0x%x\n", Driver, dev); + close(i2c_device); + } + + return 0; + + exit_error: + free(bus); + free(device); + close(i2c_device); + return -1; +} + +int drv_generic_i2c_close(void) +{ + close(i2c_device); + return 0; +} + +unsigned char drv_generic_i2c_wire(const char *name, const char *deflt) +{ + unsigned char w; + char wire[256]; + char *s; + qprintf(wire, sizeof(wire), "Wire.%s", name); + s = cfg_get(Section, wire, deflt); + if (strlen(s) == 3 && strncasecmp(s, "DB", 2) == 0 && s[2] >= '0' && s[2] <= '7') { + w = s[2] - '0'; + } else if (strcasecmp(s, "GND") == 0) { + w = 0; + } else { + error("%s: unknown signal <%s> for wire <%s>", Driver, s, name); + error("%s: should be DB0..7 or GND", Driver); + return 0xff; + } + free(s); + if (w == 0) { + info("%s: wiring: [DISPLAY:%s]<==>[i2c:GND]", Driver, name); + } else { + info("%s: wiring: [DISPLAY:%s]<==>[i2c:DB%d]", Driver, name, w); + } + w = 1 << w; + return w; +} + + +void drv_generic_i2c_data(const unsigned char data) +{ + my_i2c_smbus_write_byte_data(i2c_device, data); +} + + +void drv_generic_i2c_command(const unsigned char command, /*const */ unsigned char *data, const unsigned char length) +{ + i2c_smbus_write_block_data(i2c_device, command, length, data); +} |