lib/reg_script: Add display support

Add the ability to enable the display of the script:
* Added REG_SCRIPT_COMMAND_DISPLAY to enable and disable display output
* Added context values to manage display support
  * display_state - Updated by the command to enable or disable display
  * display_features - May be updated by step routine to control what
    the step displays for register and value
  * display_prefix - Prefix to display before register data
* Added REG_SCRIPT_DISPLAY_ON and REG_SCRIPT_DISPLAY_OFF macros to
  control the display from the register script
* Added REG_SCRIPT_DISPLAY_REGISTER and REG_SCRIPT_DISPLAY_VALUE as
  two features of the common display.  With these features enabled
  the following is output:
  * Write: <optional prefix> register <-- value
  * Read:  <optional prefix> register --> value

TEST=Build and run on Galileo Gen2

Change-Id: If0d4d61ed8ef48ec20082b327f358fd1987e3fb9
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/14553
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/include/reg_script.h

@@ -47,6 +47,10 @@ enum {
 	REG_SCRIPT_COMMAND_POLL,
 	REG_SCRIPT_COMMAND_SET_DEV,
 	REG_SCRIPT_COMMAND_NEXT,
+	REG_SCRIPT_COMMAND_DISPLAY,
+
+	/* Insert new types above this comment */
+
 	REG_SCRIPT_COMMAND_END,
 };
 
@@ -92,6 +96,9 @@ struct reg_script_context {
 	device_t dev;
 	struct resource *res;
 	const struct reg_script *step;
+	uint8_t display_state;    /* Only modified by reg_script_run_step */
+	uint8_t display_features; /* Step routine modifies to control display */
+	const char *display_prefix; /* Prefix tag to display */
 };
 
 struct reg_script_bus_entry {
@@ -132,6 +139,21 @@ struct reg_script_bus_entry {
 	  .res_index = res_index_, \
 	}
 
+/* Display control */
+#define REG_SCRIPT_DISPLAY_ALL		0xff
+#define REG_SCRIPT_DISPLAY_REGISTER	0x02
+#define REG_SCRIPT_DISPLAY_VALUE	0x01
+#define REG_SCRIPT_DISPLAY_NOTHING	0
+
+#define REG_SCRIPT_DISPLAY_OFF                   \
+	{ .command = REG_SCRIPT_COMMAND_DISPLAY, \
+	  .value = REG_SCRIPT_DISPLAY_NOTHING,   \
+	}
+#define REG_SCRIPT_DISPLAY_ON                    \
+	{ .command = REG_SCRIPT_COMMAND_DISPLAY, \
+	  .value = REG_SCRIPT_DISPLAY_ALL,       \
+	}
+
 /*
  * PCI
  */

src/lib/reg_script.c

@@ -415,24 +415,62 @@ static const struct reg_script_bus_entry
 	return NULL;
 }
 
+static void reg_script_display(struct reg_script_context *ctx,
+	const struct reg_script *step, const char *arrow, uint64_t value)
+{
+	/* Display the register address and data */
+	if (ctx->display_prefix != NULL)
+		printk(BIOS_INFO, "%s: ", ctx->display_prefix);
+	if (ctx->display_features & REG_SCRIPT_DISPLAY_REGISTER)
+		printk(BIOS_INFO, "0x%08x %s ", step->reg, arrow);
+	if (ctx->display_features & REG_SCRIPT_DISPLAY_VALUE)
+		switch (step->size) {
+		case REG_SCRIPT_SIZE_8:
+			printk(BIOS_INFO, "0x%02x\n", (uint8_t)value);
+			break;
+		case REG_SCRIPT_SIZE_16:
+			printk(BIOS_INFO, "0x%04x\n", (int16_t)value);
+			break;
+		case REG_SCRIPT_SIZE_32:
+			printk(BIOS_INFO, "0x%08x\n", (uint32_t)value);
+			break;
+		default:
+			printk(BIOS_INFO, "0x%016llx\n", value);
+			break;
+		}
+}
+
 static uint64_t reg_script_read(struct reg_script_context *ctx)
 {
 	const struct reg_script *step = reg_script_get_step(ctx);
+	uint64_t value = 0;
 
 	switch (step->type) {
 	case REG_SCRIPT_TYPE_PCI:
-		return reg_script_read_pci(ctx);
+		ctx->display_prefix = "PCI";
+		value = reg_script_read_pci(ctx);
+		break;
 	case REG_SCRIPT_TYPE_IO:
-		return reg_script_read_io(ctx);
+		ctx->display_prefix = "IO";
+		value = reg_script_read_io(ctx);
+		break;
 	case REG_SCRIPT_TYPE_MMIO:
-		return reg_script_read_mmio(ctx);
+		ctx->display_prefix = "MMIO";
+		value = reg_script_read_mmio(ctx);
+		break;
 	case REG_SCRIPT_TYPE_RES:
-		return reg_script_read_res(ctx);
+		ctx->display_prefix = "RES";
+		value = reg_script_read_res(ctx);
+		break;
 	case REG_SCRIPT_TYPE_MSR:
-		return reg_script_read_msr(ctx);
+		ctx->display_prefix = "MSR";
+		value = reg_script_read_msr(ctx);
+		break;
 #if HAS_IOSF
 	case REG_SCRIPT_TYPE_IOSF:
-		return reg_script_read_iosf(ctx);
+		ctx->display_prefix = "IOSF";
+		value = reg_script_read_iosf(ctx);
+		break;
 #endif /* HAS_IOSF */
 	default:
 		{
@@ -441,14 +479,19 @@ static uint64_t reg_script_read(struct reg_script_context *ctx)
 			/* Read from the platform specific bus */
 			bus = find_bus(step);
 			if (NULL != bus)
-				return bus->reg_script_read(ctx);
+				value = bus->reg_script_read(ctx);
+				break;
 		}
 		printk(BIOS_ERR,
 			"Unsupported read type (0x%x) for this device!\n",
 			step->type);
-		break;
-	}
 		return 0;
+	}
+
+	/* Display the register address and data */
+	if (ctx->display_features)
+		reg_script_display(ctx, step, "-->", value);
+	return value;
 }
 
 static void reg_script_write(struct reg_script_context *ctx)
@@ -457,22 +500,28 @@ static void reg_script_write(struct reg_script_context *ctx)
 
 	switch (step->type) {
 	case REG_SCRIPT_TYPE_PCI:
+		ctx->display_prefix = "PCI";
 		reg_script_write_pci(ctx);
 		break;
 	case REG_SCRIPT_TYPE_IO:
+		ctx->display_prefix = "IO";
 		reg_script_write_io(ctx);
 		break;
 	case REG_SCRIPT_TYPE_MMIO:
+		ctx->display_prefix = "MMIO";
 		reg_script_write_mmio(ctx);
 		break;
 	case REG_SCRIPT_TYPE_RES:
+		ctx->display_prefix = "RES";
 		reg_script_write_res(ctx);
 		break;
 	case REG_SCRIPT_TYPE_MSR:
+		ctx->display_prefix = "MSR";
 		reg_script_write_msr(ctx);
 		break;
 #if HAS_IOSF
 	case REG_SCRIPT_TYPE_IOSF:
+		ctx->display_prefix = "IOSF";
 		reg_script_write_iosf(ctx);
 		break;
 #endif /* HAS_IOSF */
@@ -484,14 +533,18 @@ static void reg_script_write(struct reg_script_context *ctx)
 			bus = find_bus(step);
 			if (NULL != bus) {
 				bus->reg_script_write(ctx);
-				return;
+				break;
 			}
 		}
 		printk(BIOS_ERR,
 			"Unsupported write type (0x%x) for this device!\n",
 			step->type);
-		break;
+		return;
 	}
+
+	/* Display the register address and data */
+	if (ctx->display_features)
+		reg_script_display(ctx, step, "<--", step->value);
 }
 
 static void reg_script_rmw(struct reg_script_context *ctx)
@@ -557,6 +610,8 @@ static void reg_script_run_step(struct reg_script_context *ctx,
 {
 	uint64_t value = 0, try;
 
+	ctx->display_features = ctx->display_state;
+	ctx->display_prefix = NULL;
 	switch (step->command) {
 	case REG_SCRIPT_COMMAND_READ:
 		(void)reg_script_read(ctx);
@@ -589,6 +644,10 @@ static void reg_script_run_step(struct reg_script_context *ctx,
 	case REG_SCRIPT_COMMAND_NEXT:
 		reg_script_run_next(ctx, step->next);
 		break;
+	case REG_SCRIPT_COMMAND_DISPLAY:
+		ctx->display_state = step->value;
+		break;
+
 	default:
 		printk(BIOS_WARNING, "Invalid command: %08x\n",
 		       step->command);
@@ -624,6 +683,7 @@ void reg_script_run_on_dev(device_t dev, const struct reg_script *step)
 {
 	struct reg_script_context ctx;
 
+	ctx.display_state = REG_SCRIPT_DISPLAY_NOTHING;
 	reg_script_set_dev(&ctx, dev);
 	reg_script_set_step(&ctx, step);
 	reg_script_run_with_context(&ctx);