295367686e
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11850 a1c6a512-1295-4272-9138-f99709370657
185 lines
3.2 KiB
C
185 lines
3.2 KiB
C
#include "config.h"
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#include "cpu.h"
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#include <stdbool.h>
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#include "kernel.h"
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#include "system.h"
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#include "hwcompat.h"
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#include "logf.h"
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#include "debug.h"
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#include "string.h"
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#define SLAVE_ADDRESS 0xCC
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#define SDA_LO GPHDAT &= ~(1 << 9)
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#define SDA_HI GPHDAT |= (1 << 9)
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#define SDA_INPUT GPHCON &= ~(3 << 18)
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#define SDA_OUTPUT GPHCON |= (1 << 18)
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#define SDA GPHDAT & (1 << 9)
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#define SCL_LO GPHDAT &= ~(1 << 10)
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#define SCL_HI GPHDAT |= (1 << 10)
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#define SCL_INPUT GPHCON &= ~(3 << 20)
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#define SCL_OUTPUT GPHCON |= (1 << 20)
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#define SCL GPHDAT & (1 << 10)
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#define SCL_SDA_HI GPHDAT |= (3 << 9)
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/* The SC606 can clock at 400KHz: 2.5uS period -> 1.25uS half period */
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/* At 300Mhz - if loop takes 6 cycles @ 3.3nS each -> 1.25uS / 20nS -> 63 */
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#define DELAY do { volatile int _x; for(_x=0;_x<63;_x++);} while (0)
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static void sc606_i2c_start(void)
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{
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SCL_SDA_HI;
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DELAY;
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SDA_LO;
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DELAY;
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SCL_LO;
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}
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static void sc606_i2c_restart(void)
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{
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SCL_SDA_HI;
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DELAY;
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SDA_LO;
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DELAY;
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SCL_LO;
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}
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static void sc606_i2c_stop(void)
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{
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SDA_LO;
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DELAY;
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SCL_HI;
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DELAY;
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SDA_HI;
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DELAY;
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}
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static void sc606_i2c_ack(void)
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{
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SDA_LO;
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SCL_HI;
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DELAY;
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SCL_LO;
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}
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static int sc606_i2c_getack(void)
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{
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int ret = 0;
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/* Don't need a delay since follows a data bit with a delay on the end */
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SDA_INPUT; /* And set to input */
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SCL_HI;
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DELAY;
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if (SDA) /* ack failed */
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ret = 1;
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DELAY;
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SCL_LO;
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DELAY;
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SDA_OUTPUT;
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return ret;
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}
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static int sc606_i2c_outb(unsigned char byte)
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{
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int i;
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/* clock out each bit, MSB first */
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for (i = 0x80; i; i >>= 1) {
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if (i & byte) {
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SDA_HI;
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} else {
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SDA_LO;
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}
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DELAY;
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SCL_HI;
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DELAY;
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SCL_LO;
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DELAY;
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}
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return sc606_i2c_getack();
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}
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static unsigned char sc606_i2c_inb(void)
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{
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int i;
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unsigned char byte = 0;
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SDA_INPUT; /* And set to input */
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/* clock in each bit, MSB first */
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for (i = 0x80; i; i >>= 1) {
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SCL_HI;
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if (SDA)
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byte |= i;
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SCL_LO;
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}
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SDA_OUTPUT;
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sc606_i2c_ack();
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return byte;
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}
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int sc606_write(unsigned char reg, unsigned char data)
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{
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int x = 0;
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sc606_i2c_start();
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x += sc606_i2c_outb(SLAVE_ADDRESS);
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x += 0x10 * sc606_i2c_outb(reg);
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sc606_i2c_start();
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/* sc606_i2c_restart(); */
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x += 0x100 * sc606_i2c_outb(SLAVE_ADDRESS);
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x += 0x1000 *sc606_i2c_outb(data);
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sc606_i2c_stop();
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return x;
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}
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int sc606_read(unsigned char reg, unsigned char* data)
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{
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int x = 0;
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sc606_i2c_start();
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sc606_i2c_outb(SLAVE_ADDRESS);
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sc606_i2c_outb(reg);
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sc606_i2c_restart();
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sc606_i2c_outb(SLAVE_ADDRESS | 1);
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*data = sc606_i2c_inb();
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sc606_i2c_stop();
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return x;
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}
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void sc606_init(void)
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{
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/* Set GPB2 (EN) to 1 */
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GPBCON = (GPBCON & ~(3<<4)) | 1<<4;
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/* Turn enable line on */
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GPBDAT |= 1<<2;
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/* OFF GPBDAT &= ~(1 << 2); */
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/* About 400us - needs 350us */
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DELAY;
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DELAY;
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DELAY;
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DELAY;
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DELAY;
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/* Set GPH9 (SDA) and GPH10 (SCL) to 1 */
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GPHUP &= ~(3<<9);
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GPHCON = (GPHCON & ~(0xF<<18)) | 5<<18;
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}
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