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extmod/machine_i2c: Only use WRITE1 option if transfer supports it. 

When MICROPY_PY_MACHINE_I2C_TRANSFER_WRITE1 is enabled the port's hardware
I2C transfer functions should support the MP_MACHINE_I2C_FLAG_WRITE1
option, but software I2C will not.  So add a flag to the I2C protocol
struct so each individual protocol can indicate whether it supports this
option or not.

Fixes issue #8765.

Signed-off-by: Damien George <damien@micropython.org>
This commit is contained in:
Damien George 2022-06-17 11:57:57 +10:00
parent d7919ea71e
commit 5233fb3a3d
3 changed files with 16 additions and 13 deletions
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11
extmod/machine_i2c.c
View File

@ -515,7 +515,9 @@ STATIC int read_mem(mp_obj_t self_in, uint16_t addr, uint32_t memaddr, uint8_t a
size_t memaddr_len = fill_memaddr_buf(&memaddr_buf[0], memaddr, addrsize);
#if MICROPY_PY_MACHINE_I2C_TRANSFER_WRITE1
// The I2C transfer function may support the MP_MACHINE_I2C_FLAG_WRITE1 option
mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t *)self->type->protocol;
if (i2c_p->transfer_supports_write1) {
// Create partial write and read buffers
mp_machine_i2c_buf_t bufs[2] = {
{.len = memaddr_len, .buf = memaddr_buf},
@ -523,11 +525,10 @@ STATIC int read_mem(mp_obj_t self_in, uint16_t addr, uint32_t memaddr, uint8_t a
};
// Do write+read I2C transfer
mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t *)self->type->protocol;
return i2c_p->transfer(self, addr, 2, bufs,
MP_MACHINE_I2C_FLAG_WRITE1 | MP_MACHINE_I2C_FLAG_READ | MP_MACHINE_I2C_FLAG_STOP);
#else
}
#endif
int ret = mp_machine_i2c_writeto(self, addr, memaddr_buf, memaddr_len, false);
if (ret != memaddr_len) {
@ -536,8 +537,6 @@ STATIC int read_mem(mp_obj_t self_in, uint16_t addr, uint32_t memaddr, uint8_t a
return ret;
}
return mp_machine_i2c_readfrom(self, addr, buf, len, true);
#endif
}
STATIC int write_mem(mp_obj_t self_in, uint16_t addr, uint32_t memaddr, uint8_t addrsize, const uint8_t *buf, size_t len) {

3
extmod/machine_i2c.h
View File

@ -61,6 +61,9 @@ typedef struct _mp_machine_i2c_buf_t {
// - transfer must be non-NULL
// - transfer_single only needs to be set if transfer=mp_machine_i2c_transfer_adaptor
typedef struct _mp_machine_i2c_p_t {
#if MICROPY_PY_MACHINE_I2C_TRANSFER_WRITE1
bool transfer_supports_write1;
#endif
void (*init)(mp_obj_base_t *obj, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args);
int (*start)(mp_obj_base_t *obj);
int (*stop)(mp_obj_base_t *obj);

1
ports/esp32/machine_i2c.c
View File

@ -188,6 +188,7 @@ mp_obj_t machine_hw_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_
}
STATIC const mp_machine_i2c_p_t machine_hw_i2c_p = {
.transfer_supports_write1 = true,
.transfer = machine_hw_i2c_transfer,
};