summaryrefslogtreecommitdiff
path: root/extmod/machine_i2c.c
diff options
context:
space:
mode:
Diffstat (limited to 'extmod/machine_i2c.c')
-rw-r--r--extmod/machine_i2c.c154
1 files changed, 90 insertions, 64 deletions
diff --git a/extmod/machine_i2c.c b/extmod/machine_i2c.c
index c1a93ab04..0202fc2bb 100644
--- a/extmod/machine_i2c.c
+++ b/extmod/machine_i2c.c
@@ -180,9 +180,9 @@ STATIC int mp_hal_i2c_read_byte(machine_i2c_obj_t *self, uint8_t *val, int nack)
}
// return value:
-// >=0 - number of acks received
+// >=0 - success; for read it's 0, for write it's number of acks received
// <0 - error, with errno being the negative of the return value
-int mp_machine_soft_i2c_writeto(mp_obj_base_t *self_in, uint16_t addr, const uint8_t *src, size_t len, bool stop) {
+int mp_machine_soft_i2c_transfer(mp_obj_base_t *self_in, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags) {
machine_i2c_obj_t *self = (machine_i2c_obj_t*)self_in;
// start the I2C transaction
@@ -192,7 +192,7 @@ int mp_machine_soft_i2c_writeto(mp_obj_base_t *self_in, uint16_t addr, const uin
}
// write the slave address
- ret = mp_hal_i2c_write_byte(self, addr << 1);
+ ret = mp_hal_i2c_write_byte(self, (addr << 1) | (flags & MP_MACHINE_I2C_FLAG_READ));
if (ret < 0) {
return ret;
} else if (ret != 0) {
@@ -201,69 +201,102 @@ int mp_machine_soft_i2c_writeto(mp_obj_base_t *self_in, uint16_t addr, const uin
return -MP_ENODEV;
}
- // write the buffer to the I2C memory
- int num_acks = 0;
- while (len--) {
- ret = mp_hal_i2c_write_byte(self, *src++);
- if (ret < 0) {
- return ret;
- } else if (ret != 0) {
- // nack received, stop sending
- break;
+ int transfer_ret = 0;
+ for (; n--; ++bufs) {
+ size_t len = bufs->len;
+ uint8_t *buf = bufs->buf;
+ if (flags & MP_MACHINE_I2C_FLAG_READ) {
+ // read bytes from the slave into the given buffer(s)
+ while (len--) {
+ ret = mp_hal_i2c_read_byte(self, buf++, (n | len) == 0);
+ if (ret != 0) {
+ return ret;
+ }
+ }
+ } else {
+ // write bytes from the given buffer(s) to the slave
+ while (len--) {
+ ret = mp_hal_i2c_write_byte(self, *buf++);
+ if (ret < 0) {
+ return ret;
+ } else if (ret != 0) {
+ // nack received, stop sending
+ n = 0;
+ break;
+ }
+ ++transfer_ret; // count the number of acks
+ }
}
- ++num_acks;
}
// finish the I2C transaction
- if (stop) {
+ if (flags & MP_MACHINE_I2C_FLAG_STOP) {
ret = mp_hal_i2c_stop(self);
if (ret != 0) {
return ret;
}
}
- return num_acks;
+ return transfer_ret;
}
-// return value:
-// 0 - success
-// <0 - error, with errno being the negative of the return value
-int mp_machine_soft_i2c_readfrom(mp_obj_base_t *self_in, uint16_t addr, uint8_t *dest, size_t len, bool stop) {
- machine_i2c_obj_t *self = (machine_i2c_obj_t*)self_in;
-
- // start the I2C transaction
- int ret = mp_hal_i2c_start(self);
- if (ret != 0) {
- return ret;
- }
-
- // write the slave address
- ret = mp_hal_i2c_write_byte(self, (addr << 1) | 1);
- if (ret < 0) {
- return ret;
- } else if (ret != 0) {
- // nack received, release the bus cleanly
- mp_hal_i2c_stop(self);
- return -MP_ENODEV;
- }
-
- // read the bytes from the slave
- while (len--) {
- ret = mp_hal_i2c_read_byte(self, dest++, len == 0);
- if (ret != 0) {
- return ret;
+/******************************************************************************/
+// Generic helper functions
+
+// For use by ports that require a single buffer of data for a read/write transfer
+int mp_machine_i2c_transfer_adaptor(mp_obj_base_t *self, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags) {
+ size_t len;
+ uint8_t *buf;
+ if (n == 1) {
+ // Use given single buffer
+ len = bufs[0].len;
+ buf = bufs[0].buf;
+ } else {
+ // Combine buffers into a single one
+ len = 0;
+ for (size_t i = 0; i < n; ++i) {
+ len += bufs[i].len;
+ }
+ buf = m_new(uint8_t, len);
+ if (!(flags & MP_MACHINE_I2C_FLAG_READ)) {
+ len = 0;
+ for (size_t i = 0; i < n; ++i) {
+ memcpy(buf + len, bufs[i].buf, bufs[i].len);
+ len += bufs[i].len;
+ }
}
}
- // finish the I2C transaction
- if (stop) {
- ret = mp_hal_i2c_stop(self);
- if (ret != 0) {
- return ret;
+ mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t*)self->type->protocol;
+ int ret = i2c_p->transfer_single(self, addr, len, buf, flags);
+
+ if (n > 1) {
+ if (flags & MP_MACHINE_I2C_FLAG_READ) {
+ // Copy data from single buffer to individual ones
+ len = 0;
+ for (size_t i = 0; i < n; ++i) {
+ memcpy(bufs[i].buf, buf + len, bufs[i].len);
+ len += bufs[i].len;
+ }
}
+ m_del(uint8_t, buf, len);
}
- return 0; // success
+ return ret;
+}
+
+STATIC int mp_machine_i2c_readfrom(mp_obj_base_t *self, uint16_t addr, uint8_t *dest, size_t len, bool stop) {
+ mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t*)self->type->protocol;
+ mp_machine_i2c_buf_t buf = {.len = len, .buf = dest};
+ unsigned int flags = MP_MACHINE_I2C_FLAG_READ | (stop ? MP_MACHINE_I2C_FLAG_STOP : 0);
+ return i2c_p->transfer(self, addr, 1, &buf, flags);
+}
+
+STATIC int mp_machine_i2c_writeto(mp_obj_base_t *self, uint16_t addr, const uint8_t *src, size_t len, bool stop) {
+ mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t*)self->type->protocol;
+ mp_machine_i2c_buf_t buf = {.len = len, .buf = (uint8_t*)src};
+ unsigned int flags = stop ? MP_MACHINE_I2C_FLAG_STOP : 0;
+ return i2c_p->transfer(self, addr, 1, &buf, flags);
}
/******************************************************************************/
@@ -318,11 +351,10 @@ MP_DEFINE_CONST_FUN_OBJ_KW(machine_i2c_init_obj, 1, machine_i2c_obj_init);
STATIC mp_obj_t machine_i2c_scan(mp_obj_t self_in) {
mp_obj_base_t *self = MP_OBJ_TO_PTR(self_in);
- mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t*)self->type->protocol;
mp_obj_t list = mp_obj_new_list(0, NULL);
// 7-bit addresses 0b0000xxx and 0b1111xxx are reserved
for (int addr = 0x08; addr < 0x78; ++addr) {
- int ret = i2c_p->writeto(self, addr, NULL, 0, true);
+ int ret = mp_machine_i2c_writeto(self, addr, NULL, 0, true);
if (ret == 0) {
mp_obj_list_append(list, MP_OBJ_NEW_SMALL_INT(addr));
}
@@ -407,12 +439,11 @@ MP_DEFINE_CONST_FUN_OBJ_2(machine_i2c_write_obj, machine_i2c_write);
STATIC mp_obj_t machine_i2c_readfrom(size_t n_args, const mp_obj_t *args) {
mp_obj_base_t *self = (mp_obj_base_t*)MP_OBJ_TO_PTR(args[0]);
- mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t*)self->type->protocol;
mp_int_t addr = mp_obj_get_int(args[1]);
vstr_t vstr;
vstr_init_len(&vstr, mp_obj_get_int(args[2]));
bool stop = (n_args == 3) ? true : mp_obj_is_true(args[3]);
- int ret = i2c_p->readfrom(self, addr, (uint8_t*)vstr.buf, vstr.len, stop);
+ int ret = mp_machine_i2c_readfrom(self, addr, (uint8_t*)vstr.buf, vstr.len, stop);
if (ret < 0) {
mp_raise_OSError(-ret);
}
@@ -422,12 +453,11 @@ MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_i2c_readfrom_obj, 3, 4, machine_i2c_
STATIC mp_obj_t machine_i2c_readfrom_into(size_t n_args, const mp_obj_t *args) {
mp_obj_base_t *self = (mp_obj_base_t*)MP_OBJ_TO_PTR(args[0]);
- mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t*)self->type->protocol;
mp_int_t addr = mp_obj_get_int(args[1]);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[2], &bufinfo, MP_BUFFER_WRITE);
bool stop = (n_args == 3) ? true : mp_obj_is_true(args[3]);
- int ret = i2c_p->readfrom(self, addr, bufinfo.buf, bufinfo.len, stop);
+ int ret = mp_machine_i2c_readfrom(self, addr, bufinfo.buf, bufinfo.len, stop);
if (ret < 0) {
mp_raise_OSError(-ret);
}
@@ -437,12 +467,11 @@ MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_i2c_readfrom_into_obj, 3, 4, machine
STATIC mp_obj_t machine_i2c_writeto(size_t n_args, const mp_obj_t *args) {
mp_obj_base_t *self = (mp_obj_base_t*)MP_OBJ_TO_PTR(args[0]);
- mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t*)self->type->protocol;
mp_int_t addr = mp_obj_get_int(args[1]);
mp_buffer_info_t bufinfo;
mp_get_buffer_raise(args[2], &bufinfo, MP_BUFFER_READ);
bool stop = (n_args == 3) ? true : mp_obj_is_true(args[3]);
- int ret = i2c_p->writeto(self, addr, bufinfo.buf, bufinfo.len, stop);
+ int ret = mp_machine_i2c_writeto(self, addr, bufinfo.buf, bufinfo.len, stop);
if (ret < 0) {
mp_raise_OSError(-ret);
}
@@ -453,19 +482,18 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(machine_i2c_writeto_obj, 3, 4, machin
STATIC int read_mem(mp_obj_t self_in, uint16_t addr, uint32_t memaddr, uint8_t addrsize, uint8_t *buf, size_t len) {
mp_obj_base_t *self = (mp_obj_base_t*)MP_OBJ_TO_PTR(self_in);
- mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t*)self->type->protocol;
uint8_t memaddr_buf[4];
size_t memaddr_len = 0;
for (int16_t i = addrsize - 8; i >= 0; i -= 8) {
memaddr_buf[memaddr_len++] = memaddr >> i;
}
- int ret = i2c_p->writeto(self, addr, memaddr_buf, memaddr_len, false);
+ int ret = mp_machine_i2c_writeto(self, addr, memaddr_buf, memaddr_len, false);
if (ret != memaddr_len) {
// must generate STOP
- i2c_p->writeto(self, addr, NULL, 0, true);
+ mp_machine_i2c_writeto(self, addr, NULL, 0, true);
return ret;
}
- return i2c_p->readfrom(self, addr, buf, len, true);
+ return mp_machine_i2c_readfrom(self, addr, buf, len, true);
}
#define MAX_MEMADDR_SIZE (4)
@@ -473,7 +501,6 @@ STATIC int read_mem(mp_obj_t self_in, uint16_t addr, uint32_t memaddr, uint8_t a
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) {
mp_obj_base_t *self = (mp_obj_base_t*)MP_OBJ_TO_PTR(self_in);
- mp_machine_i2c_p_t *i2c_p = (mp_machine_i2c_p_t*)self->type->protocol;
// need some memory to create the buffer to send; try to use stack if possible
uint8_t buf2_stack[MAX_MEMADDR_SIZE + BUF_STACK_SIZE];
@@ -493,7 +520,7 @@ STATIC int write_mem(mp_obj_t self_in, uint16_t addr, uint32_t memaddr, uint8_t
}
memcpy(buf2 + memaddr_len, buf, len);
- int ret = i2c_p->writeto(self, addr, buf2, memaddr_len + len, true);
+ int ret = mp_machine_i2c_writeto(self, addr, buf2, memaddr_len + len, true);
if (buf2_alloc != 0) {
m_del(uint8_t, buf2, buf2_alloc);
}
@@ -625,8 +652,7 @@ STATIC const mp_machine_i2c_p_t mp_machine_soft_i2c_p = {
.stop = (int(*)(mp_obj_base_t*))mp_hal_i2c_stop,
.read = mp_machine_soft_i2c_read,
.write = mp_machine_soft_i2c_write,
- .readfrom = mp_machine_soft_i2c_readfrom,
- .writeto = mp_machine_soft_i2c_writeto,
+ .transfer = mp_machine_soft_i2c_transfer,
};
const mp_obj_type_t machine_i2c_type = {
generated by cgit v1.2.3 (git 2.46.0) at 2025-11-04 05:58:22 +0000