board/hyperdebug: Enumerate and configure SPI ports via USB

Add console commands: spiget and spisetspeed

The first can list information on all SPI port or a particular port.

The other, spisetspeed, can be used to modify the clock divisor between
SPI transactions.

BUG=b:192262089
TEST=Observed different clock speeds on analyzer

Change-Id: I113b8bdef48f58d5941212c8a8598f3293b5da91
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/4078008
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
Tested-by: Jes Klinke <jbk@chromium.org>
Code-Coverage: Zoss <zoss-cl-coverage@prod.google.com>
Commit-Queue: Jes Klinke <jbk@chromium.org>

2 files changed, 146 insertions, 2 deletions

diff --git a/board/hyperdebug/board.c b/board/hyperdebug/board.c
index 8e56c0359d..c9a3702d1e 100644
--- a/board/hyperdebug/board.c
+++ b/board/hyperdebug/board.c
@@ -131,7 +131,7 @@ USB_STREAM_CONFIG(usart5_usb, USB_IFACE_USART5_STREAM,
 #define SPI_CLOCK (16000000UL)
 
 /* SPI devices, default to 250 kb/s for all. */
-const struct spi_device_t spi_devices[] = {
+struct spi_device_t spi_devices[] = {
 	{ .name = "SPI2",
 	  .port = 1,
 	  .div = 5,
@@ -636,3 +636,146 @@ static int command_gpio_pull_mode(int argc, const char **argv)
 DECLARE_CONSOLE_COMMAND_FLAGS(gpiopullmode, command_gpio_pull_mode,
 			      "name <none | up | down>",
 			      "Set a GPIO weak pull mode", CMD_FLAG_RESTRICTED);
+
+/*
+ * Find spi device by name or by number.  Returns an index into spi_devices[],
+ * or on error a negative value.
+ */
+static int find_spi_by_name(const char *name)
+{
+	int i;
+	char *e;
+	i = strtoi(name, &e, 0);
+
+	if (!*e && i < spi_devices_used)
+		return i;
+
+	for (i = 0; i < spi_devices_used; i++) {
+		if (!strcasecmp(name, spi_devices[i].name))
+			return i;
+	}
+
+	/* SPI device not found */
+	return -1;
+}
+
+static void print_spi_info(int index)
+{
+	uint32_t bits_per_second;
+
+	if (spi_devices[index].usb_flags & USB_SPI_CUSTOM_SPI_DEVICE) {
+		// OCTOSPI as 8 bit prescaler, dividing clock by 1..256.
+		bits_per_second = OCTOSPI_CLOCK / (spi_devices[index].div + 1);
+	} else {
+		// Other SPIs have prescaler by power of two 2, 4, 8, ..., 256.
+		bits_per_second = SPI_CLOCK / (2 << spi_devices[index].div);
+	}
+
+	ccprintf("  %d %s %d bps\n", index, spi_devices[index].name,
+		 bits_per_second);
+
+	/* Flush console to avoid truncating output */
+	cflush();
+}
+
+/*
+ * Get information about one or all SPI ports.
+ */
+static int command_spi_info(int argc, const char **argv)
+{
+	int i;
+
+	/* If a SPI target is specified, print only that one */
+	if (argc == 3) {
+		int index = find_spi_by_name(argv[2]);
+		if (index < 0) {
+			ccprintf("SPI device not found\n");
+			return EC_ERROR_PARAM2;
+		}
+
+		print_spi_info(index);
+		return EC_SUCCESS;
+	}
+
+	/* Otherwise print them all */
+	for (i = 0; i < spi_devices_used; i++) {
+		print_spi_info(i);
+	}
+
+	return EC_SUCCESS;
+}
+
+static int command_spi_set_speed(int argc, const char **argv)
+{
+	int index;
+	uint32_t desired_speed;
+	char *e;
+	if (argc < 5)
+		return EC_ERROR_PARAM_COUNT;
+
+	index = find_spi_by_name(argv[3]);
+	if (index < 0)
+		return EC_ERROR_PARAM3;
+
+	desired_speed = strtoi(argv[4], &e, 0);
+	if (*e)
+		return EC_ERROR_PARAM4;
+
+	if (spi_devices[index].usb_flags & USB_SPI_CUSTOM_SPI_DEVICE) {
+		/*
+		 * Find prescaler value by division, rounding up in order to get
+		 * slightly slower speed than requested, if it cannot be matched
+		 * exactly.
+		 */
+		spi_devices[index].div =
+			(OCTOSPI_CLOCK + desired_speed - 1) / desired_speed - 1;
+		STM32_OCTOSPI_DCR2 = spi_devices[index].div;
+	} else {
+		int divisor = 7;
+		/*
+		 * Find the smallest divisor that result in a speed not faster
+		 * than what was requested.
+		 */
+		while (divisor > 0) {
+			if (SPI_CLOCK / (2 << (divisor - 1)) > desired_speed) {
+				/* One step further would make the clock too
+				 * fast, stop here. */
+				break;
+			}
+			divisor--;
+		}
+
+		/*
+		 * Re-initialize spi controller to apply the new clock divisor.
+		 */
+		spi_enable(&spi_devices[index], 0);
+		spi_devices[index].div = divisor;
+		spi_enable(&spi_devices[index], 1);
+	}
+
+	return EC_SUCCESS;
+}
+
+static int command_spi_set(int argc, const char **argv)
+{
+	if (argc < 3)
+		return EC_ERROR_PARAM_COUNT;
+	if (!strcasecmp(argv[2], "speed"))
+		return command_spi_set_speed(argc, argv);
+	return EC_ERROR_PARAM2;
+}
+
+static int command_spi(int argc, const char **argv)
+{
+	if (argc < 2)
+		return EC_ERROR_PARAM_COUNT;
+	if (!strcasecmp(argv[1], "info"))
+		return command_spi_info(argc, argv);
+	if (!strcasecmp(argv[1], "set"))
+		return command_spi_set(argc, argv);
+	return EC_ERROR_PARAM1;
+}
+DECLARE_CONSOLE_COMMAND_FLAGS(spi, command_spi,
+			      "info [PORT]"
+			      "\nset speed PORT BPS",
+			      "SPI bus manipulation", CMD_FLAG_RESTRICTED);
diff --git a/board/hyperdebug/board.h b/board/hyperdebug/board.h
index 86c2c88ad0..760e66aa37 100644
--- a/board/hyperdebug/board.h
+++ b/board/hyperdebug/board.h
@@ -97,13 +97,14 @@
 #define CONFIG_USB_SPI
 #define CONFIG_USB_SPI_BUFFER_SIZE 2048
 #define CONFIG_SPI_CONTROLLER
+#define CONFIG_STM32_SPI1_CONTROLLER
+#define CONFIG_SPI_MUTABLE_DEVICE_LIST
 
 /* Enable control of I2C over USB */
 #define CONFIG_USB_I2C
 #define CONFIG_I2C
 #define CONFIG_I2C_CONTROLLER
 #define I2C_PORT_CONTROLLER 0
-#define CONFIG_STM32_SPI1_CONTROLLER
 
 /* See i2c_ite_flash_support.c for more information about these values */
 /*#define CONFIG_ITE_FLASH_SUPPORT */