linux: Convert linux SPI code to use the generic spicmds.c code

Use the generic spi send/receive code on Linux.  Update the replicape
code to use the updated command format.

Also, update the replicape code to turn off the stepper motors on a
shutdown event.

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

3 files changed, 38 insertions, 11 deletions

diff --git a/src/linux/Kconfig b/src/linux/Kconfig
index 651f0874..1647ef91 100644
--- a/src/linux/Kconfig
+++ b/src/linux/Kconfig
@@ -7,6 +7,7 @@ config LINUX_SELECT
     bool
     default y
     select HAVE_GPIO_ADC
+    select HAVE_GPIO_SPI
 
 config BOARD_DIRECTORY
     string
diff --git a/src/linux/gpio.h b/src/linux/gpio.h
index a2c92520..74d9db37 100644
--- a/src/linux/gpio.h
+++ b/src/linux/gpio.h
@@ -3,6 +3,13 @@
 
 #include <stdint.h> // uint8_t
 
+struct gpio_out {
+    uint32_t pin;
+};
+struct gpio_out gpio_out_setup(uint8_t pin, uint8_t val);
+void gpio_out_toggle(struct gpio_out g);
+void gpio_out_write(struct gpio_out g, uint8_t val);
+
 struct gpio_adc {
     int fd;
 };
@@ -11,4 +18,11 @@ uint32_t gpio_adc_sample(struct gpio_adc g);
 uint16_t gpio_adc_read(struct gpio_adc g);
 void gpio_adc_cancel_sample(struct gpio_adc g);
 
+struct spi_config {
+    int fd;
+};
+struct spi_config spi_setup(uint32_t bus, uint8_t mode, uint32_t rate);
+void spi_transfer(struct spi_config config, uint8_t receive_data
+                  , uint8_t len, uint8_t *data);
+
 #endif // gpio.h
diff --git a/src/linux/spidev.c b/src/linux/spidev.c
index d68f9861..cb511205 100644
--- a/src/linux/spidev.c
+++ b/src/linux/spidev.c
@@ -1,6 +1,6 @@
-// Communicating with an SPI device via linux spidev
+// Very basic shift-register support via a Linux SPI device
 //
-// Copyright (C) 2017  Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2017-2018  Kevin O'Connor <kevin@koconnor.net>
 //
 // This file may be distributed under the terms of the GNU GPLv3 license.
 
@@ -8,6 +8,7 @@
 #include <stdio.h> // snprintf
 #include <unistd.h> // write
 #include "command.h" // DECL_COMMAND
+#include "gpio.h" // spi_setup
 #include "internal.h" // report_errno
 #include "sched.h" // shutdown
 
@@ -47,22 +48,33 @@ spi_open(uint32_t bus, uint32_t dev)
     return fd;
 }
 
-static void
-spi_write(int fd, char *data, int len)
+struct spi_config
+spi_setup(uint32_t bus, uint8_t mode, uint32_t rate)
 {
-    int ret = write(fd, data, len);
+    int bus_id = (bus >> 8) & 0xff, dev_id = bus & 0xff;
+    int fd = spi_open(bus_id, dev_id);
+    return (struct spi_config) { fd };
+}
+
+void
+spi_transfer(struct spi_config config, uint8_t receive_data
+             , uint8_t len, uint8_t *data)
+{
+    int ret = write(config.fd, data, len);
     if (ret < 0) {
         report_errno("write spi", ret);
         shutdown("Unable to write to spi");
     }
 }
 
+// Dummy versions of gpio_out functions
+struct gpio_out
+gpio_out_setup(uint8_t pin, uint8_t val)
+{
+    shutdown("gpio_out_setup not supported");
+}
+
 void
-command_send_spi(uint32_t *args)
+gpio_out_write(struct gpio_out g, uint8_t val)
 {
-    int fd = spi_open(args[0], args[1]);
-    uint8_t len = args[2];
-    char *msg = (void*)(size_t)args[3];
-    spi_write(fd, msg, len);
 }
-DECL_COMMAND(command_send_spi, "send_spi bus=%u dev=%u msg=%*s");