[bsp][esp32-c6] compile SPI when it is selected

bsp/ESP/ESP32_C6/SConstruct

@@ -111,6 +111,158 @@ def _use_c6_idf_when_official_has_none():
 
 _use_c6_idf_when_official_has_none()
 
+def _match_idf_spi_lock_stub_to_spi_config():
+    """components/esp_hw_support/port/esp32c6/spi_lock_stub.c defines
+    spicommon_bus_using_iomux() and spi_bus_lock_get_by_id() as
+    always-true/always-0, and the package's C6 block compiles it because its
+    directory scan takes every .c under that port directory that is not in
+    skip_name. It is there because the package does not build
+    components/driver/spi_common.c for C6, and components/spi_flash/
+    esp_flash_spi_init.c needs those two names: with SPI off this BSP has the
+    same hole, so the stub stays.
+
+    idf_port/SConscript compiles spi_common.c itself once BSP_USING_SPI is
+    selected, and spi_common.c:726 and :743 define the same two names -- the
+    real ones, the second of which hands the master driver a bus lock instead of
+    the stub's 0. Two strong definitions of both names in one image is a link
+    error, so the scan has to skip the stub in that configuration only. The
+    switch is written into the package's own SConscript because that scan lives
+    nowhere else; packages/ is not in the repository, so this is redone on every
+    build and on every re-fetch of the package, and it is written as bytes to
+    keep the file's own line endings.
+    """
+    import re
+    from env_package import find_package_path
+
+    with open(os.path.join(SDK_ROOT, 'rtconfig.h'), 'r',
+              encoding='utf-8', errors='replace') as f:
+        spi_selected = re.search(r'^[ \t]*#[ \t]*define[ \t]+BSP_USING_SPI[ \t]*$',
+                                 f.read(), re.M) is not None
+
+    sc = os.path.join(os.path.abspath(
+        find_package_path(SDK_ROOT, 'ESP-IDF-latest')), 'SConscript')
+    if not os.path.isfile(sc):
+        return
+    with open(sc, 'rb') as f:
+        text = f.read()
+    entry = b"\n        'spi_lock_stub',"
+    have = entry in text
+    if have == spi_selected:
+        return
+    if spi_selected:
+        marker = b'skip_name = ('
+        if marker not in text:
+            raise RuntimeError('%s has no %s to skip spi_lock_stub.c in'
+                               % (sc, marker.decode()))
+        text = text.replace(marker, marker + entry, 1)
+    else:
+        text = text.replace(entry, b'', 1)
+    with open(sc, 'wb') as f:
+        f.write(text)
+
+_match_idf_spi_lock_stub_to_spi_config()
+
+def _adapt_idf_gdma_to_c6_ll():
+    """idf_port/SConscript compiles the package's components/esp_hw_support/
+    gdma.c when BSP_USING_SPI is on, because spi_common.c's
+    SOC_GDMA_SUPPORTED section calls gdma_new_channel() and friends. That gdma.c
+    is written against the C3 generation of hal/gdma_ll.h and this package's
+    components/hal/esp32c6/include/hal/gdma_ll.h is a different one:
+
+      - gdma_ll_enable_m2m_mode() (gdma.c:259) does not exist on C6. C6 folds
+        the same thing into the two connect helpers: gdma_ll_rx_connect_to_periph
+        (gdma_ll.h:297) writes in_conf0.mem_trans_en = (periph ==
+        GDMA_TRIG_PERIPH_M2M) itself, and gdma_ll_rx_disconnect_from_periph
+        (gdma_ll.h:306) clears it. So the call goes away rather than being
+        renamed to something C6 does not do.
+      - gdma_ll_tx/rx_connect_to_periph take four arguments on C6 (gdma_ll.h:520
+        and :297) -- dev, channel, periph, periph_id -- while gdma.c:264/:269
+        pass three. gdma_trigger_t (esp_hw_support/include/esp_private/
+        gdma.h:130) keeps .periph and .instance_id apart, and .instance_id is
+        what the C3 header wrote into the same select field, so the fix is to
+        hand C6 the periph it also asks for and keep that value as periph_id.
+      - gdma.c:289/:291 disconnect by feeding GDMA_INVALID_PERIPH_TRIG back into
+        connect. C6 has no such sentinel path: it has
+        gdma_ll_tx_disconnect_from_periph (gdma_ll.h:529) and
+        gdma_ll_rx_disconnect_from_periph, which write GDMA_LL_INVALID_PERIPH_ID
+        and clear mem_trans_en.
+      - the RX connect is left inside its `periph != GDMA_TRIG_PERIPH_M2M`
+        guard, which on C6 also skips the only writer of mem_trans_en; it is
+        unguarded here and the TX guard is left alone. Rewritten below, after
+        these four.
+
+    The rewrite is here, in a tracked file, and it is a whole call expression
+    swapped for a whole call expression, so a second run finds nothing left to
+    match and cannot stack a second copy. packages/ is not in the repository.
+    """
+    import re
+    from env_package import find_package_path
+
+    gdma = os.path.join(os.path.abspath(
+        find_package_path(SDK_ROOT, 'ESP-IDF-latest')),
+        'components', 'esp_hw_support', 'gdma.c')
+    if not os.path.isfile(gdma):
+        return
+    with open(gdma, 'rb') as f:
+        text = f.read()
+
+    fixed = text
+    # C6 has no m2m setter: its rx connect sets mem_trans_en, its rx disconnect
+    # clears it. Drop the call, keep the comment above it, which still says what
+    # the connect below now does.
+    fixed = re.sub(rb'^[ \t]*gdma_ll_enable_m2m_mode\([^\r\n]*\r?\n', b'',
+                   fixed, flags=re.M)
+    for old, new in [
+            (b'gdma_ll_tx_connect_to_periph(group->hal.dev, pair->pair_id, '
+             b'trig_periph.instance_id)',
+             b'gdma_ll_tx_connect_to_periph(group->hal.dev, pair->pair_id, '
+             b'trig_periph.periph, trig_periph.instance_id)'),
+            (b'gdma_ll_rx_connect_to_periph(group->hal.dev, pair->pair_id, '
+             b'trig_periph.instance_id)',
+             b'gdma_ll_rx_connect_to_periph(group->hal.dev, pair->pair_id, '
+             b'trig_periph.periph, trig_periph.instance_id)'),
+            (b'gdma_ll_tx_connect_to_periph(group->hal.dev, pair->pair_id, '
+             b'GDMA_INVALID_PERIPH_TRIG)',
+             b'gdma_ll_tx_disconnect_from_periph(group->hal.dev, pair->pair_id)'),
+            (b'gdma_ll_rx_connect_to_periph(group->hal.dev, pair->pair_id, '
+             b'GDMA_INVALID_PERIPH_TRIG)',
+             b'gdma_ll_rx_disconnect_from_periph(group->hal.dev, pair->pair_id)'),
+    ]:
+        fixed = fixed.replace(old, new)
+
+    # The RX connect stays inside the same `periph != M2M` guard gdma.c uses for
+    # TX, and on C6 that guard is exactly what decides mem_trans_en: the only
+    # writer of that bit is gdma_ll_rx_connect_to_periph (gdma_ll.h:297-301), and
+    # it writes mem_trans_en = (periph == GDMA_TRIG_PERIPH_M2M) while doing the
+    # selection. Guarded, a memory-to-memory channel never reaches the call that
+    # would set its own mode bit, so mem_trans_en stays 0 forever. C3's
+    # gdma_ll_enable_m2m_mode -- the call removed above -- wrote that one RX bit
+    # and nothing else, so the guard replaces a call that used to be made
+    # unconditionally. TX keeps its guard: gdma_ll_tx_connect_to_periph
+    # (gdma_ll.h:520-523) throws `periph` away and writes only peri_out_sel, so
+    # for a TX channel skipping the call loses nothing.
+    rx_guarded = (
+        b'        if (trig_periph.periph != GDMA_TRIG_PERIPH_M2M) {\n'
+        b'            gdma_ll_rx_connect_to_periph(group->hal.dev, pair->pair_id,'
+        b' trig_periph.periph, trig_periph.instance_id);\n'
+        b'        }\n')
+    rx_unguarded = (
+        b'        gdma_ll_rx_connect_to_periph(group->hal.dev, pair->pair_id,'
+        b' trig_periph.periph, trig_periph.instance_id);\n')
+    for old, new in ((rx_guarded, rx_unguarded),
+                     (rx_guarded.replace(b'\n', b'\r\n'),
+                      rx_unguarded.replace(b'\n', b'\r\n'))):
+        if old in fixed:
+            fixed = fixed.replace(old, new, 1)
+            break
+
+    if fixed != text:
+        with open(gdma, 'wb') as f:
+            f.write(fixed)
+
+_adapt_idf_gdma_to_c6_ll()
+
+
 objs = PrepareBuilding(env, RTT_ROOT, remove_components = ['libc'])
 
 objs.extend(SConscript(os.path.join(libraries_path_prefix, 'drivers', 'SConscript'), variant_dir='build/libraries/drivers', duplicate=0))

bsp/ESP/ESP32_C6/idf_port/SConscript

@@ -16,4 +16,122 @@ CPPPATH = Split(
 
 group = DefineGroup('idf_port', src, depend = [''], CPPPATH = CPPPATH)
 
+# bsp/ESP/libraries/drivers/drv_spi.c calls the ESP-IDF master mode SPI driver:
+# spi_bus_initialize() lives in components/driver/spi_common.c and
+# spi_bus_add_device()/spi_device_acquire_bus()/spi_device_polling_transmit()/
+# spi_device_release_bus() in components/driver/spi_master.c. The package's own
+# driver group drops both for C6 (packages/ESP-IDF-latest/SConscript:999 keeps
+# only gpio.c, rtc_io.c, uart.c and spi_bus_lock.c out of components/driver), so
+# they are compiled here -- and only with BSP_USING_SPI selected, so a default
+# build adds nothing.
+if GetDepend(['BSP_USING_SPI']):
+    from env_package import find_package_path
+
+    bsp_root = os.path.normpath(os.path.join(GetCurrentDir(), '..'))
+    idf = find_package_path(bsp_root, 'ESP-IDF-latest',
+                            relative_to=bsp_root, pathsep='/')
+    wrapper = find_package_path(bsp_root, 'FreeRTOS-Wrapper-latest',
+                               relative_to=bsp_root, pathsep='/')
+
+    # scons resolves these against the BSP root (the variant dir 'build' mirrors
+    # them), so '..' steps out of this idf_port directory; the include
+    # directories below are absolute to stay independent of that.
+    spi_src = [
+        '../%s/components/driver/spi_common.c' % idf,
+        '../%s/components/driver/spi_master.c' % idf,
+        # spi_common.c and spi_master.c are written against the HAL layer, and
+        # this package's C6 hal group drops spi_hal.c; without it the ten
+        # spi_hal_* calls those two files make have no definition.
+        '../%s/components/hal/spi_hal.c' % idf,
+        # spi_common.c reaches GDMA through its own SOC_GDMA_SUPPORTED section
+        # (soc/esp32c6/include/soc/soc_caps.h defines it as 1), and that code is
+        # compiled into the object no matter what the third argument of
+        # spi_bus_initialize() is. The package drops every path containing
+        # 'gdma' from its C6 source list, so the driver and its hal wrapper are
+        # compiled here instead. That gdma.c is written against the C3
+        # generation of hal/gdma_ll.h; SConstruct rewrites its gdma_ll_* call
+        # sites to the prototypes in this package's C6 header before anything is
+        # compiled.
+        '../%s/components/esp_hw_support/gdma.c' % idf,
+        '../%s/components/hal/gdma_hal.c' % idf,
+        # gdma.c reads gdma_periph_signals (gdma.c:541 and on) to map a
+        # GDMA_TRIG_PERIPH_* onto the signal slots of a channel; the one object
+        # file defining it is this SoC table, which the package drops for the
+        # same 'gdma' reason as the two files above.
+        '../%s/components/soc/esp32c6/gdma_periph.c' % idf,
+        # this gcc has no __atomic_compare_exchange_1 (see the file); the byte
+        # sized compare-exchange of spi_common.c's atomic_bool needs one.
+        'src/rt_atomic_cas_stub.c',
+    ]
+
+    # headers the two files include. freertos/queue.h and freertos/task.h come
+    # from the RT-Thread FreeRTOS wrapper, like everywhere else in this BSP: the
+    # kernel copy inside the package wants an IDF sdkconfig this BSP does not
+    # carry.
+    spi_path = [os.path.join(bsp_root, idf, 'components', p) for p in (
+        'driver/include',
+        'esp_common/include',
+        'esp_hw_support/include',
+        'esp_hw_support/port/esp32c6/include',
+        'esp_rom/include',
+        'esp_system/include',
+        'esp_system/port/include',
+        'esp_system/port/include/private',
+        'esp_timer/include',
+        'hal/include',
+        'hal/esp32c6/include',
+        'hal/platform_port/include',
+        'heap/include',
+        'log/include',
+        'newlib/platform_include',
+        'riscv/include',
+        'soc/include',
+        'soc/esp32c6/include',
+    )] + [os.path.join(bsp_root, wrapper, 'FreeRTOS/include')]
+
+    # hal/esp32c6/include/hal/spi_ll.h names SPI_CLK_SRC_XTAL/SPI_CLK_SRC_RC_FAST
+    # (enumerators of soc/clk_tree_defs.h) and spi_command_t with its
+    # SPI_CMD_HD_* values, and this package snapshot defines neither of the
+    # latter anywhere -- only spi_ll.h uses them, hal/include/hal/spi_types.h has
+    # no spi_command_t. drv_spi.c carries the declarations for its own
+    # translation unit; these flags give the package's own sources the same
+    # thing. The real home of both is the package's hal/include/hal/spi_types.h.
+    # One string, because building.py appends LOCAL_CFLAGS to a CFLAGS string.
+    spi_flags = (
+        '-include soc/clk_tree_defs.h'
+        ' -Dspi_command_t=int'
+        ' -DSPI_CMD_HD_WRBUF=0x01'
+        ' -DSPI_CMD_HD_RDBUF=0x02'
+        ' -DSPI_CMD_HD_WRDMA=0x03'
+        ' -DSPI_CMD_HD_RDDMA=0x04'
+        ' -DSPI_CMD_HD_SEG_END=0x05'
+        ' -DSPI_CMD_HD_EN_QPI=0x06'
+        ' -DSPI_CMD_HD_WR_END=0x07'
+        ' -DSPI_CMD_HD_INT0=0x08'
+        ' -DSPI_CMD_HD_INT1=0x09'
+        ' -DSPI_CMD_HD_INT2=0x0A'
+    )
+
+    group += DefineGroup('idf_port_spi', spi_src, depend = ['BSP_USING_SPI'],
+                         LOCAL_CPPPATH = spi_path, LOCAL_CFLAGS = spi_flags)
+
+    # spi_hal.c is only init/deinit/cal_clock. spi_hal_setup_device,
+    # spi_hal_setup_trans, spi_hal_prepare_data, spi_hal_user_start and
+    # spi_hal_fetch_result -- everything spi_master.c drives a transfer with --
+    # are in spi_hal_iram.c, the second file of that pair, which this package's
+    # C6 drop_hal list removes as well.
+    #
+    # It is a group of its own because it is the only source that may see
+    # include/spi_ll_master_start_compat.h: that header defines a macro named
+    # spi_ll_master_user_start, and giving it to spi_common.c, spi_master.c or
+    # gdma.c would only shadow the C6 header's own helpers in files that never
+    # ask for that name.
+    iram_path = [os.path.join(bsp_root, 'idf_port', 'include')] + spi_path
+    group += DefineGroup('idf_port_spi_iram',
+                         ['../%s/components/hal/spi_hal_iram.c' % idf],
+                         depend = ['BSP_USING_SPI'],
+                         LOCAL_CPPPATH = iram_path,
+                         LOCAL_CFLAGS = spi_flags +
+                                        ' -include spi_ll_master_start_compat.h')
+
 Return('group')

bsp/ESP/ESP32_C6/idf_port/include/spi_ll_master_start_compat.h

@@ -0,0 +1,29 @@
+#ifndef RT_ESP_IDF_PORT_SPI_LL_MASTER_START_COMPAT_H
+#define RT_ESP_IDF_PORT_SPI_LL_MASTER_START_COMPAT_H
+
+#include "hal/spi_ll.h"
+
+/*
+ * components/hal/spi_hal_iram.c:188 starts the transaction with
+ * spi_ll_master_user_start(hal->hw), a name this package's
+ * hal/esp32c6/include/hal/spi_ll.h does not have. C6 splits it in two:
+ * spi_ll_apply_config() (spi_ll.h:208, sets cmd.update and waits until the
+ * peripheral has taken the configuration) and spi_ll_user_start() (spi_ll.h:231,
+ * sets cmd.usr). The six targets whose spi_ll.h does define
+ * spi_ll_master_user_start -- esp32, esp32c2, esp32c3, esp32h2, esp32s2,
+ * esp32s3 -- all define it as those same two writes, in this order. So this is
+ * not a substitute for the C6 sequence, it is the C6 sequence under the name the
+ * shared spi_hal_iram.c asks for.
+ *
+ * Included with -include, for that one source file only (idf_port/SConscript),
+ * so no other translation unit sees the name. packages/ is not in the
+ * repository, which is why the fix lives here.
+ */
+#define spi_ll_master_user_start(hw) \
+    do                               \
+    {                                \
+        spi_ll_apply_config(hw);     \
+        spi_ll_user_start(hw);       \
+    } while (0)
+
+#endif /* RT_ESP_IDF_PORT_SPI_LL_MASTER_START_COMPAT_H */

bsp/ESP/ESP32_C6/idf_port/src/rt_atomic_cas_stub.c

@@ -0,0 +1,55 @@
+#include <rtthread.h>
+
+/*
+ * spi_common.c claims a bus with
+ *     atomic_compare_exchange_strong(&spi_periph_claimed[host], &expected, value)
+ * on an _Atomic bool, and an ESP32-C6 core can only reserve a whole word, so
+ * this gcc emits a call to the out-of-line helper instead of an lr/sc sequence.
+ * The install has no __atomic_compare_exchange_1:
+ *     riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/11.2.0/libgcc.a  ->  0 hits
+ * and there is no libatomic.a next to it, so the name stays undefined at link
+ * time. The prototype below is the one the compiler itself declares -- it
+ * rejects any other spelling with -Wbuiltin-declaration-mismatch -- and it
+ * matches what the call site really passes: the address of the object, the
+ * address of the expected byte, the desired byte, and two memory orders. The
+ * `weak` argument is not passed in a register at all (an atomic_compare_exchange
+ * weak/strong pair compiles to the same five loads), which is why it is ignored
+ * here; the helper's answer is always the strong one, so a weak CAS merely gets
+ * one it did not ask for.
+ *
+ * Masking interrupts is enough for this SoC: it has one core, so the only other
+ * writer of these bytes is an interrupt handler.
+ */
+_Bool __atomic_compare_exchange_1(volatile void *object,
+                                  void *expected,
+                                  unsigned char desired,
+                                  _Bool weak,
+                                  int success,
+                                  int failure)
+{
+    volatile unsigned char *addr = (volatile unsigned char *)object;
+    unsigned char *compare = (unsigned char *)expected;
+    rt_base_t level;
+    _Bool exchanged;
+
+    (void)weak;
+    (void)success;
+    (void)failure;
+
+    level = rt_hw_interrupt_disable();
+
+    if (*addr == *compare)
+    {
+        *addr = desired;
+        exchanged = 1;
+    }
+    else
+    {
+        *compare = *addr;
+        exchanged = 0;
+    }
+
+    rt_hw_interrupt_enable(level);
+
+    return exchanged;
+}

bsp/ESP/libraries/drivers/Kconfig

@@ -123,7 +123,7 @@ menu "On-chip Peripheral Drivers"
 
     menuconfig BSP_USING_SPI
         bool "Enable SPI"
-        depends on SOC_ESP32_C3
+        depends on SOC_ESP32_C3 || SOC_ESP32_C6
         default n
         select RT_USING_SPI
         if BSP_USING_SPI