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#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <stdio.h>
#include "platform.h"
#include "gt911.h"
#define CMD_SLEEP 0x05
#define REG_CMD 0x8040
#define REG_CMD2 0x8046
#define REG_STATUS 0x814E
#define REG_POINTS 0x814F
#define REG_CFG 0x8047
#define REG_CHKSUM 0x80FF
#define REG_MOD_SW1 0x804D
#define REG_REF_RATE 0x8056
#define REG_X_THR 0x8057
#define REG_Y_THR 0x8058
#define REG_PROD_ID 0x8140
#define REG_FW_VER 0x8144
static int g911_command(uint8_t command) {
int rv;
if (command > 0x07) {
rv = drv_i2c_write16(GT911_ADDR, REG_CMD2, &command, 1);
if (rv) return rv;
}
rv = drv_i2c_write16(GT911_ADDR, REG_CMD, &command, 1);
if (rv) return rv;
return DRV_OK;
}
static uint8_t gt911_chksum(uint8_t *buf, uint8_t len) {
int i;
uint8_t csum = 0;
for(i=0; i<len; i++) {
csum += buf[i];
}
// csum %= 256;
csum = (~csum) + 1;
return csum;
}
static int gt911_chip_id(char *buf) {
int rv;
rv = drv_i2c_read16(GT911_ADDR, REG_PROD_ID, buf, 4);
return rv;
}
static int gt911_fw_ver(char *buf) {
int rv;
rv = drv_i2c_read16(GT911_ADDR, REG_FW_VER, buf, 2);
return rv;
}
void gt911_reset(void) {
/* INT and RST output and low */
drv_gpio_clear(GPIO_INPUT_EN, GT911_PIN_INT);
drv_gpio_clear(GPIO_OUTPUT_VAL, GT911_PIN_INT);
drv_gpio_clear(GPIO_OUTPUT_VAL, GT911_PIN_RST);
drv_gpio_set(GPIO_OUTPUT_EN, GT911_PIN_INT);
drv_gpio_set(GPIO_OUTPUT_EN, GT911_PIN_RST);
/* T2: > 10ms */
drv_sleep(12);
/* high: 0x28/0x29 (0x14 7bit), low: 0xBA/0xBB (0x5D 7bit) */
if (GT911_ADDR == 0x14) {
drv_gpio_set(GPIO_OUTPUT_VAL, GT911_PIN_INT);
}
/* T3: > 100us */
drv_sleep(1);
drv_gpio_clear(GPIO_OUTPUT_EN, GT911_PIN_RST);
/* T4: > 5ms */
drv_sleep(6);
drv_gpio_clear(GPIO_OUTPUT_VAL, GT911_PIN_INT);
/* end select I2C slave addr */
/* T5: > 50ms */
drv_sleep(51);
/* set INT as input */
drv_gpio_clear(GPIO_OUTPUT_EN, GT911_PIN_INT);
drv_gpio_set(GPIO_INPUT_EN, GT911_PIN_INT);
}
int gt911_sleep(void) {
int rv;
drv_gpio_clear(GPIO_INPUT_EN, GT911_PIN_INT);
drv_gpio_clear(GPIO_OUTPUT_VAL, GT911_PIN_INT);
drv_gpio_set(GPIO_OUTPUT_EN, GT911_PIN_INT);
rv = g911_command(CMD_SLEEP);
if (rv) return rv;
return DRV_OK;
}
void gt911_wake(void) {
drv_gpio_set(GPIO_OUTPUT_VAL, GT911_PIN_INT);
drv_gpio_set(GPIO_OUTPUT_EN, GT911_PIN_INT);
drv_sleep(5);
drv_gpio_clear(GPIO_OUTPUT_EN, GT911_PIN_INT);
drv_gpio_clear(GPIO_OUTPUT_VAL, GT911_PIN_INT);
drv_gpio_set(GPIO_INPUT_EN, GT911_PIN_INT);
}
int gt911_cfg_read(uint8_t *cfg_buf) {
int rv;
rv = drv_i2c_read16(GT911_ADDR, REG_CFG, cfg_buf, GT911_SIZE_CFG);
return rv;
}
int gt911_cfg_write(uint8_t *cfg_buf) {
int rv;
cfg_buf[GT911_SIZE_CFG - 2] = gt911_chksum(cfg_buf, GT911_SIZE_CFG - 2);
cfg_buf[GT911_SIZE_CFG - 1] = 1;
rv = drv_i2c_write16(GT911_ADDR, REG_CFG, cfg_buf, GT911_SIZE_CFG);
return rv;
}
int gt911_cfg_print(void) {
int i, rv;
uint8_t cfg_buf[GT911_SIZE_CFG];
rv = gt911_cfg_read(cfg_buf);
if (rv) return rv;
printf("GT911 CFG:\n");
for (i=0; i<GT911_SIZE_CFG-2; i++) {
printf("%.2X", cfg_buf[i]);
if (i % 8 == 7) {
printf("\n");
} else {
printf(" ");
}
}
rv = gt911_fw_ver(cfg_buf);
if (rv) return rv;
printf("GT911 FW VER:%.2X%.2X\n", cfg_buf[1], cfg_buf[0]);
return DRV_OK;
}
void gt911_set_reg(uint8_t *cfg_buf, uint16_t reg, uint8_t val) {
cfg_buf[reg - REG_CFG] = val;
}
uint8_t gt911_get_reg(uint8_t *cfg_buf, uint16_t reg) {
return cfg_buf[reg - REG_CFG];
}
int gt911_configure(void) {
int rv;
uint8_t cfg_buf[GT911_SIZE_CFG];
uint8_t reg;
rv = gt911_cfg_read(cfg_buf);
if (rv) return rv;
/* XY coordinate output threshold: 1 */
gt911_set_reg(cfg_buf, REG_X_THR, 1);
gt911_set_reg(cfg_buf, REG_Y_THR, 1);
/* INT triggering mechanism: falling edge */
reg = gt911_get_reg(cfg_buf, REG_MOD_SW1);
reg &= 0xFC;
reg |= 1;
gt911_set_reg(cfg_buf, REG_MOD_SW1, reg);
/* Coordinates report rate: 5 ms */
reg = gt911_get_reg(cfg_buf, REG_REF_RATE);
reg &= 0xF0;
gt911_set_reg(cfg_buf, REG_REF_RATE, reg);
rv = gt911_cfg_write(cfg_buf);
return rv;
}
int gt911_set_status(uint8_t status) {
int rv;
rv = drv_i2c_write16(GT911_ADDR, REG_STATUS, &status, 1);
return rv;
}
int gt911_get_status(uint8_t *status) {
int rv;
rv = drv_i2c_read16(GT911_ADDR, REG_STATUS, status, 1);
return rv;
}
int gt911_get_points(int num_points, uint8_t *points) {
int rv;
rv = drv_i2c_read16(GT911_ADDR, REG_POINTS, points, GT911_SIZE_PBUF * num_points);
return rv;
}
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