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-rw-r--r--extmod/machine_i2c.c150
1 files changed, 71 insertions, 79 deletions
diff --git a/extmod/machine_i2c.c b/extmod/machine_i2c.c
index ceddf0730e..e201b23990 100644
--- a/extmod/machine_i2c.c
+++ b/extmod/machine_i2c.c
@@ -34,6 +34,9 @@
#if MICROPY_PY_MACHINE_I2C
+// Clock stretching limit, so that we don't get stuck.
+#define I2C_STRETCH_LIMIT 255
+
typedef struct _machine_i2c_obj_t {
mp_obj_base_t base;
uint32_t us_delay;
@@ -53,6 +56,11 @@ STATIC void mp_hal_i2c_scl_low(machine_i2c_obj_t *self) {
STATIC void mp_hal_i2c_scl_release(machine_i2c_obj_t *self) {
mp_hal_pin_od_high(self->scl);
+ mp_hal_i2c_delay(self);
+ // For clock stretching, wait for the SCL pin to be released, with timeout.
+ for (int count = I2C_STRETCH_LIMIT; mp_hal_pin_read(self->scl) == 0 && count; --count) {
+ mp_hal_delay_us_fast(1);
+ }
}
STATIC void mp_hal_i2c_sda_low(machine_i2c_obj_t *self) {
@@ -71,7 +79,6 @@ STATIC void mp_hal_i2c_start(machine_i2c_obj_t *self) {
mp_hal_i2c_sda_release(self);
mp_hal_i2c_delay(self);
mp_hal_i2c_scl_release(self);
- mp_hal_i2c_delay(self);
mp_hal_i2c_sda_low(self);
mp_hal_i2c_delay(self);
}
@@ -81,7 +88,6 @@ STATIC void mp_hal_i2c_stop(machine_i2c_obj_t *self) {
mp_hal_i2c_sda_low(self);
mp_hal_i2c_delay(self);
mp_hal_i2c_scl_release(self);
- mp_hal_i2c_delay(self);
mp_hal_i2c_sda_release(self);
mp_hal_i2c_delay(self);
}
@@ -108,14 +114,12 @@ STATIC int mp_hal_i2c_write_byte(machine_i2c_obj_t *self, uint8_t val) {
}
mp_hal_i2c_delay(self);
mp_hal_i2c_scl_release(self);
- mp_hal_i2c_delay(self);
mp_hal_i2c_scl_low(self);
}
mp_hal_i2c_sda_release(self);
mp_hal_i2c_delay(self);
mp_hal_i2c_scl_release(self);
- mp_hal_i2c_delay(self);
int ret = mp_hal_i2c_sda_read(self);
mp_hal_i2c_delay(self);
@@ -124,24 +128,6 @@ STATIC int mp_hal_i2c_write_byte(machine_i2c_obj_t *self, uint8_t val) {
return !ret;
}
-STATIC void mp_hal_i2c_write(machine_i2c_obj_t *self, uint8_t addr, uint8_t *data, size_t len) {
- mp_hal_i2c_start(self);
- if (!mp_hal_i2c_write_byte(self, addr << 1)) {
- goto er;
- }
- while (len--) {
- if (!mp_hal_i2c_write_byte(self, *data++)) {
- goto er;
- }
- }
- mp_hal_i2c_stop(self);
- return;
-
-er:
- mp_hal_i2c_stop(self);
- nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error"));
-}
-
STATIC int mp_hal_i2c_read_byte(machine_i2c_obj_t *self, uint8_t *val, int nack) {
mp_hal_i2c_delay(self);
mp_hal_i2c_scl_low(self);
@@ -150,7 +136,6 @@ STATIC int mp_hal_i2c_read_byte(machine_i2c_obj_t *self, uint8_t *val, int nack)
uint8_t data = 0;
for (int i = 7; i >= 0; i--) {
mp_hal_i2c_scl_release(self);
- mp_hal_i2c_delay(self);
data = (data << 1) | mp_hal_i2c_sda_read(self);
mp_hal_i2c_scl_low(self);
mp_hal_i2c_delay(self);
@@ -163,40 +148,33 @@ STATIC int mp_hal_i2c_read_byte(machine_i2c_obj_t *self, uint8_t *val, int nack)
}
mp_hal_i2c_delay(self);
mp_hal_i2c_scl_release(self);
- mp_hal_i2c_delay(self);
mp_hal_i2c_scl_low(self);
mp_hal_i2c_sda_release(self);
return 1; // success
}
-STATIC void mp_hal_i2c_read(machine_i2c_obj_t *self, uint8_t addr, uint8_t *data, size_t len) {
- mp_hal_i2c_start(self);
- if (!mp_hal_i2c_write_byte(self, (addr << 1) | 1)) {
- goto er;
+// addr is the device address, memaddr is a memory address sent big-endian
+STATIC int mp_hal_i2c_write_addresses(machine_i2c_obj_t *self, uint8_t addr,
+ uint32_t memaddr, uint8_t addrsize) {
+ if (!mp_hal_i2c_write_byte(self, addr << 1)) {
+ return 0; // error
}
- while (len--) {
- if (!mp_hal_i2c_read_byte(self, data++, len == 0)) {
- goto er;
+ for (int16_t i = addrsize - 8; i >= 0; i -= 8) {
+ if (!mp_hal_i2c_write_byte(self, memaddr >> i)) {
+ return 0; // error
}
}
- mp_hal_i2c_stop(self);
- return;
-
-er:
- mp_hal_i2c_stop(self);
- nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error"));
+ return 1; // success
}
-STATIC void mp_hal_i2c_write_mem(machine_i2c_obj_t *self, uint8_t addr, uint16_t memaddr, const uint8_t *src, size_t len) {
+STATIC void mp_hal_i2c_write_mem(machine_i2c_obj_t *self, uint8_t addr,
+ uint32_t memaddr, uint8_t addrsize, const uint8_t *src, size_t len) {
// start the I2C transaction
mp_hal_i2c_start(self);
// write the slave address and the memory address within the slave
- if (!mp_hal_i2c_write_byte(self, addr << 1)) {
- goto er;
- }
- if (!mp_hal_i2c_write_byte(self, memaddr)) {
+ if (!mp_hal_i2c_write_addresses(self, addr, memaddr, addrsize)) {
goto er;
}
@@ -216,20 +194,30 @@ er:
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error"));
}
-STATIC void mp_hal_i2c_read_mem(machine_i2c_obj_t *self, uint8_t addr, uint16_t memaddr, uint8_t *dest, size_t len) {
+STATIC void mp_hal_i2c_read_mem(machine_i2c_obj_t *self, uint8_t addr,
+ uint32_t memaddr, uint8_t addrsize, uint8_t *dest, size_t len) {
// start the I2C transaction
mp_hal_i2c_start(self);
- // write the slave address and the memory address within the slave
- if (!mp_hal_i2c_write_byte(self, addr << 1)) {
- goto er;
+ if (addrsize) {
+ // write the slave address and the memory address within the slave
+ if (!mp_hal_i2c_write_addresses(self, addr, memaddr, addrsize)) {
+ goto er;
+ }
+
+ // i2c_read will do a repeated start, and then read the I2C memory
+ mp_hal_i2c_start(self);
}
- if (!mp_hal_i2c_write_byte(self, memaddr)) {
+
+ if (!mp_hal_i2c_write_byte(self, (addr << 1) | 1)) {
goto er;
}
-
- // i2c_read will do a repeated start, and then read the I2C memory
- mp_hal_i2c_read(self, addr, dest, len);
+ while (len--) {
+ if (!mp_hal_i2c_read_byte(self, dest++, len == 0)) {
+ goto er;
+ }
+ }
+ mp_hal_i2c_stop(self);
return;
er:
@@ -237,6 +225,14 @@ er:
nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, "I2C bus error"));
}
+STATIC void mp_hal_i2c_write(machine_i2c_obj_t *self, uint8_t addr, const uint8_t *src, size_t len) {
+ mp_hal_i2c_write_mem(self, addr, 0, 0, src, len);
+}
+
+STATIC void mp_hal_i2c_read(machine_i2c_obj_t *self, uint8_t addr, uint8_t *dest, size_t len) {
+ mp_hal_i2c_read_mem(self, addr, 0, 0, dest, len);
+}
+
/******************************************************************************/
// MicroPython bindings for I2C
@@ -276,7 +272,7 @@ STATIC mp_obj_t machine_i2c_scan(mp_obj_t self_in) {
// 7-bit addresses 0b0000xxx and 0b1111xxx are reserved
for (int addr = 0x08; addr < 0x78; ++addr) {
mp_hal_i2c_start(self);
- int ack = mp_hal_i2c_write_byte(self, (addr << 1) | 1);
+ int ack = mp_hal_i2c_write_byte(self, (addr << 1));
if (ack) {
mp_obj_list_append(list, MP_OBJ_NEW_SMALL_INT(addr));
}
@@ -365,68 +361,64 @@ STATIC mp_obj_t machine_i2c_writeto(mp_obj_t self_in, mp_obj_t addr_in, mp_obj_t
}
STATIC MP_DEFINE_CONST_FUN_OBJ_3(machine_i2c_writeto_obj, machine_i2c_writeto);
+STATIC const mp_arg_t machine_i2c_mem_allowed_args[] = {
+ { MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
+ { MP_QSTR_memaddr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
+ { MP_QSTR_arg, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
+ { MP_QSTR_addrsize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} },
+};
+
STATIC mp_obj_t machine_i2c_readfrom_mem(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_addr, ARG_memaddr, ARG_n, ARG_addrsize };
- static const mp_arg_t allowed_args[] = {
- { MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
- { MP_QSTR_memaddr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
- { MP_QSTR_n, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
- //{ MP_QSTR_addrsize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} }, TODO
- };
machine_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
- mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
- mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+ mp_arg_val_t args[MP_ARRAY_SIZE(machine_i2c_mem_allowed_args)];
+ mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args,
+ MP_ARRAY_SIZE(machine_i2c_mem_allowed_args), machine_i2c_mem_allowed_args, args);
// create the buffer to store data into
vstr_t vstr;
- vstr_init_len(&vstr, args[ARG_n].u_int);
+ vstr_init_len(&vstr, mp_obj_get_int(args[ARG_n].u_obj));
// do the transfer
- mp_hal_i2c_read_mem(self, args[ARG_addr].u_int, args[ARG_memaddr].u_int, (uint8_t*)vstr.buf, vstr.len);
+ mp_hal_i2c_read_mem(self, args[ARG_addr].u_int, args[ARG_memaddr].u_int,
+ args[ARG_addrsize].u_int, (uint8_t*)vstr.buf, vstr.len);
return mp_obj_new_str_from_vstr(&mp_type_bytes, &vstr);
}
MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_readfrom_mem_obj, 1, machine_i2c_readfrom_mem);
+
STATIC mp_obj_t machine_i2c_readfrom_mem_into(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_addr, ARG_memaddr, ARG_buf, ARG_addrsize };
- static const mp_arg_t allowed_args[] = {
- { MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
- { MP_QSTR_memaddr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
- { MP_QSTR_buf, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
- //{ MP_QSTR_addrsize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} }, TODO
- };
machine_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
- mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
- mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+ mp_arg_val_t args[MP_ARRAY_SIZE(machine_i2c_mem_allowed_args)];
+ mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args,
+ MP_ARRAY_SIZE(machine_i2c_mem_allowed_args), machine_i2c_mem_allowed_args, args);
// get the buffer to store data into
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[ARG_buf].u_obj, &bufinfo, MP_BUFFER_WRITE);
// do the transfer
- mp_hal_i2c_read_mem(self, args[ARG_addr].u_int, args[ARG_memaddr].u_int, bufinfo.buf, bufinfo.len);
+ mp_hal_i2c_read_mem(self, args[ARG_addr].u_int, args[ARG_memaddr].u_int,
+ args[ARG_addrsize].u_int, bufinfo.buf, bufinfo.len);
return mp_const_none;
}
MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_readfrom_mem_into_obj, 1, machine_i2c_readfrom_mem_into);
STATIC mp_obj_t machine_i2c_writeto_mem(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_addr, ARG_memaddr, ARG_buf, ARG_addrsize };
- static const mp_arg_t allowed_args[] = {
- { MP_QSTR_addr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
- { MP_QSTR_memaddr, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
- { MP_QSTR_buf, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
- //{ MP_QSTR_addrsize, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} }, TODO
- };
machine_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
- mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
- mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+ mp_arg_val_t args[MP_ARRAY_SIZE(machine_i2c_mem_allowed_args)];
+ mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args,
+ MP_ARRAY_SIZE(machine_i2c_mem_allowed_args), machine_i2c_mem_allowed_args, args);
// get the buffer to write the data from
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[ARG_buf].u_obj, &bufinfo, MP_BUFFER_READ);
// do the transfer
- mp_hal_i2c_write_mem(self, args[ARG_addr].u_int, args[ARG_memaddr].u_int, bufinfo.buf, bufinfo.len);
+ mp_hal_i2c_write_mem(self, args[ARG_addr].u_int, args[ARG_memaddr].u_int,
+ args[ARG_addrsize].u_int, bufinfo.buf, bufinfo.len);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_writeto_mem_obj, 1, machine_i2c_writeto_mem);
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-21 13:52:07 +0000