spicmds: Rework spi config commands

Rework the spi_config commands so that bus configuration and shutdown
message configuration is done separately from the main "config_spi"
command.  This makes the spi configuration more flexible.  It's now
possible to use software spi without a CS pin.  It's now possible to
define multiple SPI messages to send on a shutdown event.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 64 insertions, 55 deletions

diff --git a/src/spicmds.c b/src/spicmds.c
index 527cb0af..654e9436 100644
--- a/src/spicmds.c
+++ b/src/spicmds.c
@@ -1,6 +1,6 @@
 // Commands for sending messages on an SPI bus
 //
-// Copyright (C) 2016-2018  Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2016-2019  Kevin O'Connor <kevin@koconnor.net>
 //
 // This file may be distributed under the terms of the GNU GPLv3 license.
 
@@ -20,80 +20,64 @@ struct spidev_s {
     };
     struct gpio_out pin;
     uint8_t flags;
-    uint8_t shutdown_msg_len;
-    uint8_t shutdown_msg[];
 };
 
 enum {
-    SF_HAVE_PIN = 1, SF_SOFTWARE = 2,
+    SF_HAVE_PIN = 1, SF_SOFTWARE = 2, SF_HARDWARE = 4,
 };
 
 void
 command_config_spi(uint32_t *args)
 {
-    uint8_t mode = args[3], shutdown_msg_len = args[5];
-    if (mode > 3)
-        shutdown("Invalid spi mode");
-    struct spidev_s *spi = oid_alloc(args[0], command_config_spi
-                                     , sizeof(*spi) + shutdown_msg_len);
-    spi->pin = gpio_out_setup(args[2], 1);
-    spi->flags = SF_HAVE_PIN;
-    spi->spi_config = spi_setup(args[1], mode, args[4]);
-    spi->shutdown_msg_len = shutdown_msg_len;
-    uint8_t *shutdown_msg = (void*)(size_t)args[6];
-    memcpy(spi->shutdown_msg, shutdown_msg, shutdown_msg_len);
+    struct spidev_s *spi = oid_alloc(args[0], command_config_spi, sizeof(*spi));
+    spi->pin = gpio_out_setup(args[1], 1);
+    spi->flags |= SF_HAVE_PIN;
 }
-DECL_COMMAND(command_config_spi,
-             "config_spi oid=%c spi_bus=%u pin=%u mode=%u rate=%u"
-             " shutdown_msg=%*s");
+DECL_COMMAND(command_config_spi, "config_spi oid=%c pin=%u");
 
 void
 command_config_spi_without_cs(uint32_t *args)
 {
-    uint8_t mode = args[2], shutdown_msg_len = args[4];
-    if (mode > 3)
-        shutdown("Invalid spi mode");
-    struct spidev_s *spi = oid_alloc(args[0], command_config_spi
-                                     , sizeof(*spi) + shutdown_msg_len);
-    spi->spi_config = spi_setup(args[1], mode, args[3]);
-    spi->shutdown_msg_len = shutdown_msg_len;
-    uint8_t *shutdown_msg = (void*)(size_t)args[5];
-    memcpy(spi->shutdown_msg, shutdown_msg, shutdown_msg_len);
+    struct spidev_s *spi = oid_alloc(args[0], command_config_spi, sizeof(*spi));
+}
+DECL_COMMAND(command_config_spi_without_cs, "config_spi_without_cs oid=%c");
+
+struct spidev_s *
+spidev_oid_lookup(uint8_t oid)
+{
+    return oid_lookup(oid, command_config_spi);
 }
-DECL_COMMAND(command_config_spi_without_cs,
-             "config_spi_without_cs oid=%c spi_bus=%u mode=%u rate=%u"
-             " shutdown_msg=%*s");
 
 void
-command_config_spi_from_software(uint32_t *args)
+command_spi_set_bus(uint32_t *args)
 {
-    uint8_t shutdown_msg_len = args[3];
-    struct spi_software *sspi = spi_software_oid_lookup(args[1]);
-    struct spidev_s *spi = oid_alloc(args[0], command_config_spi
-                                     , sizeof(*spi) + shutdown_msg_len);
-    spi->pin = gpio_out_setup(args[2], 1);
-    spi->flags = SF_HAVE_PIN | SF_SOFTWARE;
-    spi->spi_software = sspi;
-    spi->shutdown_msg_len = shutdown_msg_len;
-    uint8_t *shutdown_msg = (void*)(size_t)args[4];
-    memcpy(spi->shutdown_msg, shutdown_msg, shutdown_msg_len);
+    struct spidev_s *spi = spidev_oid_lookup(args[0]);
+    uint8_t mode = args[2];
+    if (mode > 3 || spi->flags & (SF_SOFTWARE|SF_HARDWARE))
+        shutdown("Invalid spi config");
+    spi->spi_config = spi_setup(args[1], mode, args[3]);
+    spi->flags |= SF_HARDWARE;
 }
-#if CONFIG_HAVE_GPIO_BITBANGING
-DECL_COMMAND(command_config_spi_from_software,
-             "config_spi_from_software oid=%c sw_oid=%u pin=%u"
-             " shutdown_msg=%*s");
-#endif
+DECL_COMMAND(command_spi_set_bus,
+             "spi_set_bus oid=%c spi_bus=%u mode=%u rate=%u");
 
-struct spidev_s *
-spidev_oid_lookup(uint8_t oid)
+void
+spidev_set_software_bus(struct spidev_s *spi, struct spi_software *ss)
 {
-    return oid_lookup(oid, command_config_spi);
+    if (spi->flags & (SF_SOFTWARE|SF_HARDWARE))
+        shutdown("Invalid spi config");
+    spi->spi_software = ss;
+    spi->flags |= SF_SOFTWARE;
 }
 
 void
 spidev_transfer(struct spidev_s *spi, uint8_t receive_data
                 , uint8_t data_len, uint8_t *data)
 {
+    if (!(spi->flags & (SF_SOFTWARE|SF_HARDWARE)))
+        // Not yet initialized
+        return;
+
     if (CONFIG_HAVE_GPIO_BITBANGING && spi->flags & SF_SOFTWARE)
         spi_software_prepare(spi->spi_software);
     else
@@ -115,7 +99,7 @@ void
 command_spi_transfer(uint32_t *args)
 {
     uint8_t oid = args[0];
-    struct spidev_s *spi = oid_lookup(oid, command_config_spi);
+    struct spidev_s *spi = spidev_oid_lookup(oid);
     uint8_t data_len = args[1];
     uint8_t *data = (void*)(size_t)args[2];
     spidev_transfer(spi, 1, data_len, data);
@@ -126,14 +110,39 @@ DECL_COMMAND(command_spi_transfer, "spi_transfer oid=%c data=%*s");
 void
 command_spi_send(uint32_t *args)
 {
-    uint8_t oid = args[0];
-    struct spidev_s *spi = oid_lookup(oid, command_config_spi);
+    struct spidev_s *spi = spidev_oid_lookup(args[0]);
     uint8_t data_len = args[1];
     uint8_t *data = (void*)(size_t)args[2];
     spidev_transfer(spi, 0, data_len, data);
 }
 DECL_COMMAND(command_spi_send, "spi_send oid=%c data=%*s");
 
+
+/****************************************************************
+ * Shutdown handling
+ ****************************************************************/
+
+struct spidev_shutdown_s {
+    struct spidev_s *spi;
+    uint8_t shutdown_msg_len;
+    uint8_t shutdown_msg[];
+};
+
+void
+command_config_spi_shutdown(uint32_t *args)
+{
+    struct spidev_s *spi = spidev_oid_lookup(args[1]);
+    uint8_t shutdown_msg_len = args[2];
+    struct spidev_shutdown_s *sd = oid_alloc(
+        args[0], command_config_spi_shutdown, sizeof(*sd) + shutdown_msg_len);
+    sd->spi = spi;
+    sd->shutdown_msg_len = shutdown_msg_len;
+    uint8_t *shutdown_msg = (void*)(size_t)args[3];
+    memcpy(sd->shutdown_msg, shutdown_msg, shutdown_msg_len);
+}
+DECL_COMMAND(command_config_spi_shutdown,
+             "config_spi_shutdown oid=%c spi_oid=%c shutdown_msg=%*s");
+
 void
 spidev_shutdown(void)
 {
@@ -146,9 +155,9 @@ spidev_shutdown(void)
     }
 
     // Send shutdown messages
-    foreach_oid(oid, spi, command_config_spi) {
-        if (spi->shutdown_msg_len)
-            spidev_transfer(spi, 0, spi->shutdown_msg_len, spi->shutdown_msg);
+    struct spidev_shutdown_s *sd;
+    foreach_oid(oid, sd, command_config_spi_shutdown) {
+        spidev_transfer(sd->spi, 0, sd->shutdown_msg_len, sd->shutdown_msg);
     }
 }
 DECL_SHUTDOWN(spidev_shutdown);