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Merge pull request #829 from jerryneedell/jerryn_i2c

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add keyword timeout to I2C -- only used for bitbangioi
This commit is contained in:
Scott Shawcroft 2018-05-16 14:52:11 -04:00 committed by GitHub
commit 99e34e38eb
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GPG Key ID: 4AEE18F83AFDEB23
10 changed files with 30 additions and 17 deletions
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2
ports/atmel-samd/common-hal/busio/I2C.c
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@ -41,7 +41,7 @@
#define ATTEMPTS 2
void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
const mcu_pin_obj_t* scl, const mcu_pin_obj_t* sda, uint32_t frequency) {
const mcu_pin_obj_t* scl, const mcu_pin_obj_t* sda, uint32_t frequency, uint32_t timeout) {
Sercom* sercom = NULL;
uint8_t sercom_index;
uint32_t sda_pinmux = 0;

2
ports/nrf/common-hal/busio/I2C.c
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@ -32,7 +32,7 @@
#include "pins.h"
#include "nrf.h"
void common_hal_busio_i2c_construct(busio_i2c_obj_t *self, const mcu_pin_obj_t* scl, const mcu_pin_obj_t* sda, uint32_t frequency) {
void common_hal_busio_i2c_construct(busio_i2c_obj_t *self, const mcu_pin_obj_t* scl, const mcu_pin_obj_t* sda, uint32_t frequency, uint32_t timeout ) {
if (scl->pin == sda->pin) {
mp_raise_ValueError("Invalid pins");
}

4
py/objexcept.c
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@ -275,9 +275,7 @@ MP_DEFINE_EXCEPTION(Exception, BaseException)
MP_DEFINE_EXCEPTION(UnboundLocalError, NameError)
*/
MP_DEFINE_EXCEPTION(OSError, Exception)
#if MICROPY_PY_BUILTINS_TIMEOUTERROR
MP_DEFINE_EXCEPTION(TimeoutError, OSError)
#endif
MP_DEFINE_EXCEPTION(TimeoutError, OSError)
/*
MP_DEFINE_EXCEPTION(BlockingIOError, OSError)
MP_DEFINE_EXCEPTION(ChildProcessError, OSError)

7
shared-bindings/bitbangio/I2C.c
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@ -35,6 +35,7 @@
#include "lib/utils/context_manager_helpers.h"
#include "py/mperrno.h"
#include "py/runtime.h"
//| .. currentmodule:: bitbangio
//|
//| :class:`I2C` --- Two wire serial protocol
@ -49,6 +50,7 @@
//| :param ~microcontroller.Pin scl: The clock pin
//| :param ~microcontroller.Pin sda: The data pin
//| :param int frequency: The clock frequency of the bus
//| :param int timeout: The maximum clock stretching timeout in microseconds
//|
STATIC mp_obj_t bitbangio_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *pos_args) {
mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, true);
@ -57,11 +59,12 @@ STATIC mp_obj_t bitbangio_i2c_make_new(const mp_obj_type_t *type, size_t n_args,
self->base.type = &bitbangio_i2c_type;
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw, pos_args + n_args);
enum { ARG_scl, ARG_sda, ARG_frequency };
enum { ARG_scl, ARG_sda, ARG_frequency, ARG_timeout };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_scl, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_frequency, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 255} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, &kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
@ -69,7 +72,7 @@ STATIC mp_obj_t bitbangio_i2c_make_new(const mp_obj_type_t *type, size_t n_args,
assert_pin(args[ARG_sda].u_obj, false);
const mcu_pin_obj_t* scl = MP_OBJ_TO_PTR(args[ARG_scl].u_obj);
const mcu_pin_obj_t* sda = MP_OBJ_TO_PTR(args[ARG_sda].u_obj);
shared_module_bitbangio_i2c_construct(self, scl, sda, args[ARG_frequency].u_int);
shared_module_bitbangio_i2c_construct(self, scl, sda, args[ARG_frequency].u_int, args[ARG_timeout].u_int);
return (mp_obj_t)self;
}

3
shared-bindings/bitbangio/I2C.h
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@ -39,7 +39,8 @@ extern const mp_obj_type_t bitbangio_i2c_type;
extern void shared_module_bitbangio_i2c_construct(bitbangio_i2c_obj_t *self,
const mcu_pin_obj_t * scl,
const mcu_pin_obj_t * sda,
uint32_t frequency);
uint32_t frequency,
uint32_t us_timeout);
extern void shared_module_bitbangio_i2c_deinit(bitbangio_i2c_obj_t *self);
extern bool shared_module_bitbangio_i2c_deinited(bitbangio_i2c_obj_t *self);

6
shared-bindings/busio/I2C.c
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@ -56,6 +56,7 @@
//| :param ~microcontroller.Pin scl: The clock pin
//| :param ~microcontroller.Pin sda: The data pin
//| :param int frequency: The clock frequency in Hertz
//| :param int timeout: The maximum clock stretching timeut - only for bitbang
//|
STATIC mp_obj_t busio_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *pos_args) {
mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, true);
@ -63,11 +64,12 @@ STATIC mp_obj_t busio_i2c_make_new(const mp_obj_type_t *type, size_t n_args, siz
self->base.type = &busio_i2c_type;
mp_map_t kw_args;
mp_map_init_fixed_table(&kw_args, n_kw, pos_args + n_args);
enum { ARG_scl, ARG_sda, ARG_frequency };
enum { ARG_scl, ARG_sda, ARG_frequency, ARG_timeout };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_scl, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_frequency, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 255} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, &kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
@ -77,7 +79,7 @@ STATIC mp_obj_t busio_i2c_make_new(const mp_obj_type_t *type, size_t n_args, siz
assert_pin_free(scl);
const mcu_pin_obj_t* sda = MP_OBJ_TO_PTR(args[ARG_sda].u_obj);
assert_pin_free(sda);
common_hal_busio_i2c_construct(self, scl, sda, args[ARG_frequency].u_int);
common_hal_busio_i2c_construct(self, scl, sda, args[ARG_frequency].u_int, args[ARG_timeout].u_int);
return (mp_obj_t)self;
}

3
shared-bindings/busio/I2C.h
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@ -46,7 +46,8 @@ extern const mp_obj_type_t busio_i2c_type;
extern void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
const mcu_pin_obj_t * scl,
const mcu_pin_obj_t * sda,
uint32_t frequency);
uint32_t frequency,
uint32_t timeout);
extern void common_hal_busio_i2c_deinit(busio_i2c_obj_t *self);
extern bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self);

15
shared-module/bitbangio/I2C.c
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@ -25,16 +25,15 @@
*/
#include "shared-bindings/bitbangio/I2C.h"
#include "py/mperrno.h"
#include "py/obj.h"
#include "py/runtime.h"
#include "common-hal/microcontroller/Pin.h"
#include "shared-bindings/microcontroller/__init__.h"
#include "shared-bindings/digitalio/DigitalInOut.h"
#include "shared-module/bitbangio/types.h"
#define I2C_STRETCH_LIMIT 255
STATIC void delay(bitbangio_i2c_obj_t *self) {
// We need to use an accurate delay to get acceptable I2C
@ -48,11 +47,16 @@ STATIC void scl_low(bitbangio_i2c_obj_t *self) {
STATIC void scl_release(bitbangio_i2c_obj_t *self) {
common_hal_digitalio_digitalinout_set_value(&self->scl, true);
uint32_t count = self->us_timeout;
delay(self);
// For clock stretching, wait for the SCL pin to be released, with timeout.
for (int count = I2C_STRETCH_LIMIT; !common_hal_digitalio_digitalinout_get_value(&self->scl) && count; --count) {
for (; !common_hal_digitalio_digitalinout_get_value(&self->scl) && count; --count) {
common_hal_mcu_delay_us(1);
}
// raise exception on timeout
if (count == 0) {
mp_raise_msg(&mp_type_TimeoutError, "Clock stretch too long");
}
}
STATIC void sda_low(bitbangio_i2c_obj_t *self) {
@ -142,7 +146,10 @@ STATIC bool read_byte(bitbangio_i2c_obj_t *self, uint8_t *val, bool ack) {
void shared_module_bitbangio_i2c_construct(bitbangio_i2c_obj_t *self,
const mcu_pin_obj_t * scl,
const mcu_pin_obj_t * sda,
uint32_t frequency) {
uint32_t frequency,
uint32_t us_timeout) {
self->us_timeout = us_timeout;
self->us_delay = 500000 / frequency;
if (self->us_delay == 0) {
self->us_delay = 1;

1
shared-module/bitbangio/types.h
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@ -36,6 +36,7 @@ typedef struct {
digitalio_digitalinout_obj_t scl;
digitalio_digitalinout_obj_t sda;
uint32_t us_delay;
uint32_t us_timeout;
volatile bool locked;
} bitbangio_i2c_obj_t;

4
shared-module/busio/I2C.c
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@ -30,8 +30,8 @@
#include "py/nlr.h"
void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
const mcu_pin_obj_t* scl, const mcu_pin_obj_t* sda, uint32_t freq) {
shared_module_bitbangio_i2c_construct(&self->bitbang, scl, sda, freq);
const mcu_pin_obj_t* scl, const mcu_pin_obj_t* sda, uint32_t freq, uint32_t timeout) {
shared_module_bitbangio_i2c_construct(&self->bitbang, scl, sda, freq, timeout);
}
bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {