esp8266/modpybhspi: Add a HSPI module for hardware SPI support

This module uses ESP8266's SPI hardware, which allows much higher
speeds. It uses a library from
https://github.com/MetalPhreak/ESP8266_SPI_Driver

1 files changed, 258 insertions, 0 deletions

diff --git a/esp8266/modpybhspi.c b/esp8266/modpybhspi.c
new file mode 100644
index 0000000000..ad78c83fd8
--- /dev/null
+++ b/esp8266/modpybhspi.c
@@ -0,0 +1,258 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "ets_sys.h"
+#include "etshal.h"
+#include "ets_alt_task.h"
+
+#include "py/runtime.h"
+#include "py/stream.h"
+#include "py/mphal.h"
+
+#include "hspi.h"
+
+
+typedef struct _pyb_hspi_obj_t {
+    mp_obj_base_t base;
+    uint32_t baudrate;
+    uint8_t polarity;
+    uint8_t phase;
+} pyb_hspi_obj_t;
+
+
+/******************************************************************************/
+// MicroPython bindings for HSPI
+
+STATIC void pyb_hspi_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
+    pyb_hspi_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    mp_printf(print, "HSPI(baudrate=%u, polarity=%u, phase=%u)",
+        self->baudrate, self->polarity, self->phase);
+}
+
+STATIC void pyb_hspi_init_helper(pyb_hspi_obj_t *self, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_baudrate, ARG_polarity, ARG_phase };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_baudrate, MP_ARG_INT, {.u_int = -1} },
+        { MP_QSTR_polarity, MP_ARG_INT, {.u_int = -1} },
+        { MP_QSTR_phase, MP_ARG_INT, {.u_int = -1} },
+    };
+    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);
+
+    if (args[ARG_baudrate].u_int != -1) {
+        self->baudrate = args[ARG_baudrate].u_int;
+    }
+    if (args[ARG_polarity].u_int != -1) {
+        self->polarity = args[ARG_polarity].u_int;
+    }
+    if (args[ARG_phase].u_int != -1) {
+        self->phase = args[ARG_phase].u_int;
+    }
+    if (self->baudrate == 80000000L) {
+        // Special case for full speed.
+        spi_init_gpio(HSPI, SPI_CLK_80MHZ_NODIV);
+        spi_clock(HSPI, 0, 0);
+    } else if (self->baudrate > 40000000L) {
+        nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError,
+            "impossible baudrate"));
+    } else {
+        uint32_t divider = 40000000L / self->baudrate;
+        uint16_t prediv = MIN(divider, SPI_CLKDIV_PRE + 1);
+        uint16_t cntdiv = (divider / prediv) * 2; // cntdiv has to be even
+        if (cntdiv > SPI_CLKCNT_N + 1 || cntdiv == 0 || prediv == 0) {
+            nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError,
+                "impossible baudrate"));
+        }
+        self->baudrate = 80000000L / (prediv * cntdiv);
+        spi_init_gpio(HSPI, SPI_CLK_USE_DIV);
+        spi_clock(HSPI, prediv, cntdiv);
+    }
+    // TODO: Make the byte order configurable too (discuss param names)
+    spi_tx_byte_order(HSPI, SPI_BYTE_ORDER_HIGH_TO_LOW);
+    spi_rx_byte_order(HSPI, SPI_BYTE_ORDER_HIGH_TO_LOW);
+    CLEAR_PERI_REG_MASK(SPI_USER(HSPI), SPI_FLASH_MODE | SPI_USR_MISO |
+                        SPI_USR_ADDR | SPI_USR_COMMAND | SPI_USR_DUMMY);
+    // Clear Dual or Quad lines transmission mode
+    CLEAR_PERI_REG_MASK(SPI_CTRL(HSPI), SPI_QIO_MODE | SPI_DIO_MODE |
+                        SPI_DOUT_MODE | SPI_QOUT_MODE);
+    spi_mode(HSPI, self->phase, self->polarity);
+}
+
+STATIC mp_obj_t pyb_hspi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+    mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, true);
+    pyb_hspi_obj_t *self = m_new_obj(pyb_hspi_obj_t);
+    self->base.type = &pyb_hspi_type;
+    // set defaults
+    self->baudrate = 80000000L;
+    self->polarity = 0;
+    self->phase = 0;
+    mp_map_t kw_args;
+    mp_map_init_fixed_table(&kw_args, n_kw, args + n_args);
+    pyb_hspi_init_helper(self, n_args, args, &kw_args);
+    return MP_OBJ_FROM_PTR(self);
+}
+
+STATIC mp_obj_t pyb_hspi_init(size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
+    pyb_hspi_init_helper(args[0], n_args - 1, args + 1, kw_args);
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_KW(pyb_hspi_init_obj, 1, pyb_hspi_init);
+
+
+STATIC mp_obj_t pyb_hspi_read(size_t n_args, const mp_obj_t *args) {
+    vstr_t dest_buf;
+    vstr_init_len(&dest_buf, mp_obj_get_int(args[1]));
+    uint8_t write_byte = 0;
+    if (n_args == 3) {
+        write_byte = mp_obj_get_int(args[2]);
+    }
+    // Process data in chunks, let the pending tasks run in between
+    size_t chunk_size = 1024; // TODO this should depend on baudrate
+    size_t count = dest_buf.len / chunk_size;
+    size_t i = 0;
+    for (size_t j = 0; j < count; ++j) {
+        for (size_t k = 0; k < chunk_size; ++k) {
+            ((uint8_t*)dest_buf.buf)[i] = spi_transaction(HSPI, 0, 0, 0, 0, 8,
+                (uint32_t)write_byte, 8, 0);
+            ++i;
+        }
+        ets_loop_iter();
+    }
+    while (i < dest_buf.len) {
+        ((uint8_t*)dest_buf.buf)[i] = spi_transaction(HSPI, 0, 0, 0, 0, 8,
+            (uint32_t)write_byte, 8, 0);
+        ++i;
+    }
+    return mp_obj_new_str_from_vstr(&mp_type_bytes, &dest_buf);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_hspi_read_obj, 2, 3, pyb_hspi_read);
+
+
+STATIC mp_obj_t pyb_hspi_readinto(size_t n_args, const mp_obj_t *args) {
+    mp_buffer_info_t dest_buf;
+    mp_get_buffer_raise(args[1], &dest_buf, MP_BUFFER_WRITE);
+    uint8_t write_byte = 0;
+    if (n_args == 3) {
+        write_byte = mp_obj_get_int(args[2]);
+    }
+
+    size_t chunk_size = 1024;
+    size_t count = dest_buf.len / chunk_size;
+    size_t i = 0;
+    for (size_t j = 0; j < count; ++j) {
+        for (size_t k = 0; k < chunk_size; ++k) {
+            ((uint8_t*)dest_buf.buf)[i] = spi_transaction(HSPI, 0, 0, 0, 0, 8,
+                (uint32_t)write_byte, 8, 0);
+            ++i;
+        }
+        ets_loop_iter();
+    }
+    while (i < dest_buf.len) {
+        ((uint8_t*)dest_buf.buf)[i] = spi_transaction(HSPI, 0, 0, 0, 0, 8,
+            (uint32_t)write_byte, 8, 0);
+        ++i;
+    }
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_hspi_readinto_obj, 2, 3, pyb_hspi_readinto);
+
+
+STATIC mp_obj_t pyb_hspi_write(mp_obj_t self_in, mp_obj_t wr_buf_in) {
+    mp_buffer_info_t src_buf;
+    mp_get_buffer_raise(wr_buf_in, &src_buf, MP_BUFFER_READ);
+
+    size_t chunk_size = 1024;
+    size_t count = src_buf.len / chunk_size;
+    size_t i = 0;
+    for (size_t j = 0; j < count; ++j) {
+        for (size_t k = 0; k < chunk_size; ++k) {
+            spi_tx8fast(HSPI, ((const uint8_t*)src_buf.buf)[i]);
+            ++i;
+        }
+        ets_loop_iter();
+    }
+    while (i < src_buf.len) {
+        spi_tx8fast(HSPI, ((const uint8_t*)src_buf.buf)[i]);
+        ++i;
+    }
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_2(pyb_hspi_write_obj, pyb_hspi_write);
+
+
+STATIC mp_obj_t pyb_hspi_write_readinto(mp_obj_t self_in, mp_obj_t wr_buf_in, mp_obj_t rd_buf_in) {
+    mp_buffer_info_t src_buf;
+    mp_get_buffer_raise(wr_buf_in, &src_buf, MP_BUFFER_READ);
+    mp_buffer_info_t dest_buf;
+    mp_get_buffer_raise(rd_buf_in, &dest_buf, MP_BUFFER_WRITE);
+    if (src_buf.len != dest_buf.len) {
+        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
+            "buffers must be the same length"));
+    }
+
+    size_t chunk_size = 1024;
+    size_t count = src_buf.len / chunk_size;
+    size_t i = 0;
+    for (size_t j = 0; j < count; ++j) {
+        for (size_t k = 0; k < chunk_size; ++k) {
+            ((uint8_t*)dest_buf.buf)[i] = spi_transaction(HSPI, 0, 0, 0, 0, 8,
+                (uint32_t)(((const uint8_t*)src_buf.buf)[i]), 8, 0);
+            ++i;
+        }
+        ets_loop_iter();
+    }
+    while (i < src_buf.len) {
+        ((uint8_t*)dest_buf.buf)[i] = spi_transaction(HSPI, 0, 0, 0, 0, 8,
+            (uint32_t)(((const uint8_t*)src_buf.buf)[i]), 8, 0);
+        ++i;
+    }
+    return mp_const_none;
+}
+MP_DEFINE_CONST_FUN_OBJ_3(pyb_hspi_write_readinto_obj, pyb_hspi_write_readinto);
+
+
+STATIC const mp_rom_map_elem_t pyb_hspi_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&pyb_hspi_init_obj) },
+    { MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&pyb_hspi_read_obj) },
+    { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&pyb_hspi_readinto_obj) },
+    { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&pyb_hspi_write_obj) },
+    { MP_ROM_QSTR(MP_QSTR_write_readinto), MP_ROM_PTR(&pyb_hspi_write_readinto_obj) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(pyb_hspi_locals_dict, pyb_hspi_locals_dict_table);
+
+const mp_obj_type_t pyb_hspi_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_HSPI,
+    .print = pyb_hspi_print,
+    .make_new = pyb_hspi_make_new,
+    .locals_dict = (mp_obj_dict_t*)&pyb_hspi_locals_dict,
+};