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i2c: use speed setting from newer library version

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This commit is contained in:
Karl Palsson 2017-03-23 23:58:20 +00:00
parent 5e1ba40641
commit f34641e25b
2 changed files with 1 additions and 96 deletions
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2
libopencm3

@ -1 +1 @@
Subproject commit 3f65af8ccc09a2cff09c761924cb3776c69c2824
Subproject commit f4a82997e3408135528c8736eddc79a29891b2e5

95
tests/i2c-master/i2c-master.c
View file

@ -27,101 +27,6 @@ enum sht21_cmd_e {
// ------------------ section proposed to go up to libopencm3
/**
* I2C speed modes.
*/
enum i2c_speeds {
i2c_speed_sm_100k,
i2c_speed_fm_400k,
i2c_speed_fmp_1m,
i2c_speed_unknown
};
/* to go to i2c-v1 impl file, with common name.... */
/**
* Set the i2c communicaton speed.
* @param p i2c peripheral, eg I2C1
* @param speed one of the listed speed modes @ref i2c_speeds
* @param clock_megahz i2c peripheral clock speed in MHz. Usually, rcc_apb1_frequency / 1e6
*/
static void i2c_set_speed_v1(uint32_t p, enum i2c_speeds speed, uint32_t clock_megahz)
{
i2c_set_clock_frequency(p, clock_megahz);
switch(speed) {
case i2c_speed_fm_400k:
i2c_set_fast_mode(p);
i2c_set_ccr(p, clock_megahz * 5 / 6);
i2c_set_trise(p, clock_megahz + 1);
break;
default:
/* fall back to standard mode */
case i2c_speed_sm_100k:
i2c_set_standard_mode(p);
/* x Mhz / (100kHz * 2) */
i2c_set_ccr(p, clock_megahz * 5);
/* Sm mode, (100kHz) freqMhz + 1 */
i2c_set_trise(p, clock_megahz + 1);
break;
}
}
/* to go to i2c-v2 impl file, with common name.... */
/**
* Set the i2c communicaton speed.
* NOTE: 1MHz mode not yet implemented!
* Min clock speed: 8MHz for FM, 2Mhz for SM,
* @param p i2c peripheral, eg I2C1
* @param speed one of the listed speed modes @ref i2c_speeds
* @param clock_megahz i2c peripheral clock speed in MHz. Usually, rcc_apb1_frequency / 1e6
*/
static void i2c_set_speed_v2(uint32_t p, enum i2c_speeds speed, uint32_t clock_megahz)
{
int prescaler;
switch(speed) {
case i2c_speed_fmp_1m:
/* FIXME - add support for this mode! */
break;
case i2c_speed_fm_400k:
/* target 8Mhz input, so tpresc = 125ns */
prescaler = clock_megahz / 8 - 1;
i2c_set_prescaler(p, prescaler);
i2c_set_scl_low_period(p, 0x9); // 1250ns
i2c_set_scl_high_period(p, 3); // 500ns
i2c_set_data_hold_time(p, 2); // 250ns
i2c_set_data_setup_time(p, 2); // 375ns
break;
default:
/* fall back to standard mode */
case i2c_speed_sm_100k:
/* target 2Mhz input, so tpresc = 500ns */
prescaler = clock_megahz / 4 - 1;
i2c_set_prescaler(p, prescaler);
i2c_set_scl_low_period(p, 0x13); // 5usecs
i2c_set_scl_high_period(p, 0xf); // 4usecs
i2c_set_data_hold_time(p, 2); // 0.5usecs
i2c_set_data_setup_time(p, 4); // 1.25usecs
break;
}
}
/* requires clock to be a multiple of 2 ! */
/**
* Set the i2c line speed as optimally as possible
* @param p
* @param speed
* @param clock_megahz _normally_ provide: rcc_apb1_frequency / 1000000 here
* TODO: clock must be a multiple of 2meg for -v2 at least, improve docs here!
*/
static void i2c_set_speed(uint32_t p, enum i2c_speeds speed, uint32_t clock_megahz)
{
#if defined I2C_SR2
i2c_set_speed_v1(p, speed, clock_megahz);
#else
i2c_set_speed_v2(p, speed, clock_megahz);
#endif
}
static void i2c_write7_v1(uint32_t i2c, int addr, uint8_t *data, size_t n)
{