eeptools: Add the POWER_SUPPLY atom

The POWER_SUPPLY atom describes the ability of the HAT to supply
power to the Pi. This is declared in the EEPROM settings text file
using the current_supply property. The default value for current_supply
is zero, and unless a non-zero value is provided then the POWER_SUPPLY
atom is omitted from the EEPROM image.

Signed-off-by: Phil Elwell <[email protected]>

Author: pelwell

eeptools/eepdump.c

@@ -9,15 +9,17 @@
 static struct var_blob_t dt_atom, custom_atom;
 static struct vendor_info_d vinf;
 static struct gpio_map_d gpiomap;
+static struct power_supply_d supply;
 static const char *blob_prefix;
 
 static const char *atom_type_names[] ={
 		[ATOM_INVALID_TYPE] = "invalid",
-		[ATOM_VENDOR_TYPE] = "vendor type",
+		[ATOM_VENDOR_TYPE] = "vendor",
 		[ATOM_GPIO_TYPE] = "GPIO map",
 		[ATOM_DT_TYPE] = "DT overlay",
 		[ATOM_CUSTOM_TYPE] = "manufacturer custom data",
 		[ATOM_GPIO_BANK1_TYPE] = "GPIO map bank 1",
+		[ATOM_POWER_SUPPLY_TYPE] = "power supply",
 };
 
 static void dump_data(FILE *out, const uint8_t *data, int len)
@@ -165,6 +167,14 @@ static int read_bin(const char *in, const char *outf)
 			fprintf(out, "product \"%s\"   # length=%u\n", vinf.pstr, vinf.pslen);
 			break;
 
+		case ATOM_POWER_SUPPLY_TYPE:
+			if (!eepio_atom_power_supply(&supply))
+				goto atom_read_err;
+
+			fprintf(out, "# power supply\n");
+			fprintf(out, "current_supply %u\n", supply.current_supply);
+			break;
+
 		case ATOM_GPIO_BANK1_TYPE:
 			bank1 = true;
 			/* fall through... */

eeptools/eeplib.c

@@ -312,6 +312,12 @@ bool eepio_atom_vinf(struct vendor_info_d *vinf)
 	return !eepio_got_error();
 }
 
+bool eepio_atom_power_supply(struct power_supply_d *power)
+{
+	eepio_blob(power, POWER_SUPPLY_SIZE);
+	return !eepio_got_error();
+}
+
 bool eepio_atom_gpio(struct gpio_map_d *map)
 {
 	eepio_blob(map, GPIO_SIZE);

eeptools/eeplib.h

@@ -14,6 +14,7 @@
 #define VENDOR_SIZE 22
 #define GPIO_SIZE 30
 #define GPIO_BANK1_SIZE 20
+#define POWER_SUPPLY_SIZE 4
 #define CRC_SIZE 2
 
 #define GPIO_MIN 2
@@ -40,6 +41,7 @@ enum atom_type_t
 	ATOM_DT_TYPE = 0x0003,
 	ATOM_CUSTOM_TYPE = 0x0004,
 	ATOM_GPIO_BANK1_TYPE = 0x0005,
+	ATOM_POWER_SUPPLY_TYPE = 0x0006,
 	ATOM_HINVALID_TYPE = 0xffff
 };
 
@@ -102,6 +104,12 @@ struct gpio_map_d
 	unsigned char pins[GPIO_COUNT];
 };
 
+/* Power supply atom data */
+struct power_supply_d
+{
+	uint32_t current_supply; /* In milliamps */
+};
+
 extern struct header_t eep_header;
 extern struct atom_t eep_atom_header;
 extern uint16_t eep_atom_crc;
@@ -113,6 +121,7 @@ bool eepio_atom_start(enum atom_type_t *ptype, uint32_t *pdlen);
 bool eepio_atom_vinf(struct vendor_info_d *vinf);
 bool eepio_atom_gpio(struct gpio_map_d *map);
 bool eepio_atom_gpio_bank1(struct gpio_map_d *map);
+bool eepio_atom_power_supply(struct power_supply_d *power);
 bool eepio_atom_var(struct var_blob_t *var);
 void eepio_atom_end(void);
 void eepio_clear_error(void);

eeptools/eepmake.c

@@ -13,17 +13,24 @@
 #include "eeplib.h"
 
 static struct vendor_info_d vinf;
-static struct gpio_map_d gpiomap_bank0, gpiomap_bank1;
 static struct var_blob_t dt_blob;
 struct var_blob_t *custom_blobs;
 static struct var_blob_t *data_blob;
 bool in_string;
 
-static bool product_serial_set, product_id_set, product_ver_set, vendor_set, product_set,
-	gpio_drive_set, gpio_slew_set, gpio_hysteresis_set, gpio_power_set,
+/* Common features */
+static bool product_serial_set, product_id_set, product_ver_set, vendor_set, product_set;
+static bool has_dt;
+
+/* Legacy V1 features */
+static struct gpio_map_d gpiomap_bank0, gpiomap_bank1;
+static bool has_gpio_bank0, has_gpio_bank1;
+static bool gpio_drive_set, gpio_slew_set, gpio_hysteresis_set, gpio_power_set,
 	bank1_gpio_drive_set, bank1_gpio_slew_set, bank1_gpio_hysteresis_set;
 
-static bool has_dt, has_gpio_bank0, has_gpio_bank1;
+/* HAT+ features */
+static struct power_supply_d power_supply;
+static bool current_supply_set, has_power_supply;
 
 static unsigned int custom_ct, data_cap, custom_cap;
 
@@ -39,6 +46,14 @@ static void fatal_error(const char *msg, ...)
 	exit(1);
 }
 
+static void hatplus_required(const char *cmd)
+{
+	if (hat_format >= EEP_VERSION_HATPLUS)
+		return;
+	printf("'%s' not supported on V1 HAT\n", cmd);
+	exit(1);
+}
+
 static void hatplus_unsupported(const char *cmd)
 {
 	if (hat_format == EEP_VERSION_HATV1)
@@ -101,6 +116,14 @@ static int write_binary(const char *out)
 		eepio_atom_end();
 	}
 
+	if (has_power_supply)
+	{
+		type = ATOM_POWER_SUPPLY_TYPE;
+		eepio_atom_start(&type, NULL);
+		eepio_atom_power_supply(&power_supply);
+		eepio_atom_end();
+	}
+
 	eepio_end();
 
 	fclose(fp);
@@ -327,6 +350,18 @@ static int parse_command(char *cmd, char *c)
 		vinf.pslen = strlen(vinf.pstr);
 	}
 
+	/* HAT+ features */
+	else if (strcmp(cmd, "current_supply") == 0)
+	{
+		hatplus_required(cmd);
+		sscanf(c, "%100s %u", cmd, &power_supply.current_supply);
+		if (power_supply.current_supply)
+		{
+			current_supply_set = true;
+			has_power_supply = true;
+		}
+	}
+
 	/* GPIO map related part */
 	else if (strcmp(cmd, "gpio_drive") == 0)
 	{

eeptools/eeprom_settings.txt

@@ -27,6 +27,9 @@ vendor "ACME Technology Company"
 # ASCII product string (max 255 characters)
 product "Special Sensor Board"
 
+# How much current the HAT+ can supply, in milliamps
+current_supply 0
+
 # Which Device Tree overlay to load
 dt_blob "acme-sensor"