103 lines
3.3 KiB
C

/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
* Copyright (C) 2012 Michael Ossmann <mike@ossmann.com>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include <libopencm3/lpc43xx/gpio.h>
#include <libopencm3/lpc43xx/scu.h>
#include <libopencm3/lpc43xx/cgu.h>
#include <libopencm3/lpc43xx/i2c.h>
//FIXME generalize and move to drivers
#define SCU_SFSI2C0_SCL_EFP (1 << 1) /* 3 ns glitch filter */
#define SCU_SFSI2C0_SCL_EHD (1 << 2) /* Fast-mode Plus transmit */
#define SCU_SFSI2C0_SCL_EZI (1 << 3) /* Enable the input receiver */
#define SCU_SFSI2C0_SCL_ZIF (1 << 7) /* Disable input glitch filter */
#define SCU_SFSI2C0_SDA_EFP (1 << 8) /* 3 ns glitch filter */
#define SCU_SFSI2C0_SDA_EHD (1 << 10) /* Fast-mode Plus transmit */
#define SCU_SFSI2C0_SDA_EZI (1 << 11) /* Enable the input receiver */
#define SCU_SFSI2C0_SDA_ZIF (1 << 15) /* Disable input glitch filter */
#define I2C_CONCLR_AAC (1 << 2) /* Assert acknowledge Clear */
#define I2C_CONCLR_SIC (1 << 3) /* I2C interrupt Clear */
#define I2C_CONCLR_STAC (1 << 5) /* START flag Clear */
#define I2C_CONCLR_I2ENC (1 << 6) /* I2C interface Disable bit */
#define I2C_CONSET_AA (1 << 2) /* Assert acknowledge flag */
#define I2C_CONSET_SI (1 << 3) /* I2C interrupt flag */
#define I2C_CONSET_STO (1 << 4) /* STOP flag */
#define I2C_CONSET_STA (1 << 5) /* START flag */
#define I2C_CONSET_I2EN (1 << 6) /* I2C interface enable */
#define CGU_SRC_32K 0x00
#define CGU_SRC_IRC 0x01
#define CGU_SRC_ENET_RX 0x02
#define CGU_SRC_ENET_TX 0x03
#define CGU_SRC_GP_CLKIN 0x04
#define CGU_SRC_XTAL 0x06
#define CGU_SRC_PLL0USB 0x07
#define CGU_SRC_PLL0AUDIO 0x08
#define CGU_SRC_PLL1 0x09
#define CGU_SRC_IDIVA 0x0C
#define CGU_SRC_IDIVB 0x0D
#define CGU_SRC_IDIVC 0x0E
#define CGU_SRC_IDIVD 0x0F
#define CGU_SRC_IDIVE 0x10
#define CGU_BASE_CLK_PD (1 << 0) /* output stage power-down */
#define CGU_BASE_CLK_AUTOBLOCK (1 << 11) /* block clock automatically */
#define CGU_BASE_CLK_SEL_SHIFT 24 /* clock source selection (5 bits) */
void i2c0_init()
{
/* enable input on SCL and SDA pins */
SCU_SFSI2C0 = (SCU_SFSI2C0_SCL_EZI | SCU_SFSI2C0_SDA_EZI);
/* use PLL1 as clock source for APB1 (including I2C0) */
CGU_BASE_APB1_CLK = (CGU_SRC_PLL1 << CGU_BASE_CLK_SEL_SHIFT);
//FIXME assuming we're on IRC at 96 MHz
/* 400 kHz I2C */
I2C0_SCLH = 120;
I2C0_SCLL = 120;
/* 100 kHz I2C */
//I2C0_SCLH = 480;
//I2C0_SCLL = 480;
/* clear the control bits */
I2C0_CONCLR = (I2C_CONCLR_AAC | I2C_CONCLR_SIC
| I2C_CONCLR_STAC | I2C_CONCLR_I2ENC);
/* enable I2C0 */
I2C0_CONSET = I2C_CONSET_I2EN;
}
int main(void)
{
int i;
i2c0_init();
//TODO I2C tx/rx
return 0;
}