imx: ventana: add 'gsc wd' command for enabling and disabling GSC watchdog

This adds information about the Gateworks System Controller to the gsc command
such as the firmware version, firmware CRC and status of the GSC watchdog
(if its enabled and if its tripped).

Additionally the 'gsc wd' command can be used to enable or disable the
watchdog with the following usage:
 gsc wd enable [30|60]
 gsc wd disable

Note that the GSC registers are battery-backed by the GSC coincell so once
eanbled, they remain enabled across power-cycles or until either the GSC
firmware has been updated or FLASH has been re-programmed by the Gateworks
JTAG adapter.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>

board/gateworks/gw_ventana/gsc.c

@@ -59,7 +59,6 @@ int gsc_i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
 	return ret;
 }
 
-#ifdef CONFIG_CMD_GSC
 static void read_hwmon(const char *name, uint reg, uint size)
 {
 	unsigned char buf[3];
@@ -78,11 +77,29 @@ static void read_hwmon(const char *name, uint reg, uint size)
 	}
 }
 
-int do_gsc(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+int gsc_info(int verbose)
 {
 	const char *model = getenv("model");
+	unsigned char buf[16];
 
 	i2c_set_bus_num(0);
+	if (gsc_i2c_read(GSC_SC_ADDR, 0, 1, buf, 16))
+		return CMD_RET_FAILURE;
+
+	printf("GSC:   v%d", buf[GSC_SC_FWVER]);
+	printf(" 0x%04x", buf[GSC_SC_FWCRC] | buf[GSC_SC_FWCRC+1]<<8);
+	printf(" WDT:%sabled", (buf[GSC_SC_CTRL1] & (1<<GSC_SC_CTRL1_WDEN))
+		? "en" : "dis");
+	if (buf[GSC_SC_STATUS] & (1 << GSC_SC_IRQ_WATCHDOG)) {
+		buf[GSC_SC_STATUS] &= ~(1 << GSC_SC_IRQ_WATCHDOG);
+		puts(" WDT_RESET");
+		gsc_i2c_write(GSC_SC_ADDR, GSC_SC_STATUS, 1,
+			      &buf[GSC_SC_STATUS], 1);
+	}
+	puts("\n");
+	if (!verbose)
+		return CMD_RET_SUCCESS;
+
 	read_hwmon("Temp",     GSC_HWMON_TEMP, 2);
 	read_hwmon("VIN",      GSC_HWMON_VIN, 3);
 	read_hwmon("VBATT",    GSC_HWMON_VBATT, 3);
@@ -115,9 +132,60 @@ int do_gsc(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	return 0;
 }
 
-U_BOOT_CMD(gsc, 1, 1, do_gsc,
-	   "GSC test",
-	   ""
-);
+#ifdef CONFIG_CMD_GSC
+static int do_gsc_wd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	unsigned char reg;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	if (strcasecmp(argv[1], "enable") == 0) {
+		int timeout = 0;
+
+		if (argc > 2)
+			timeout = simple_strtoul(argv[2], NULL, 10);
+		i2c_set_bus_num(0);
+		if (gsc_i2c_read(GSC_SC_ADDR, GSC_SC_CTRL1, 1, &reg, 1))
+			return CMD_RET_FAILURE;
+		reg &= ~((1 << GSC_SC_CTRL1_WDEN) | (1 << GSC_SC_CTRL1_WDTIME));
+		if (timeout == 60)
+			reg |= (1 << GSC_SC_CTRL1_WDTIME);
+		else
+			timeout = 30;
+		reg |= (1 << GSC_SC_CTRL1_WDEN);
+		if (gsc_i2c_write(GSC_SC_ADDR, GSC_SC_CTRL1, 1, &reg, 1))
+			return CMD_RET_FAILURE;
+		printf("GSC Watchdog enabled with timeout=%d seconds\n",
+		       timeout);
+	} else if (strcasecmp(argv[1], "disable") == 0) {
+		i2c_set_bus_num(0);
+		if (gsc_i2c_read(GSC_SC_ADDR, GSC_SC_CTRL1, 1, &reg, 1))
+			return CMD_RET_FAILURE;
+		reg &= ~((1 << GSC_SC_CTRL1_WDEN) | (1 << GSC_SC_CTRL1_WDTIME));
+		if (gsc_i2c_write(GSC_SC_ADDR, GSC_SC_CTRL1, 1, &reg, 1))
+			return CMD_RET_FAILURE;
+		printf("GSC Watchdog disabled\n");
+	} else {
+		return CMD_RET_USAGE;
+	}
+	return CMD_RET_SUCCESS;
+}
+
+static int do_gsc(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	if (argc < 2)
+		return gsc_info(1);
+
+	if (strcasecmp(argv[1], "wd") == 0)
+		return do_gsc_wd(cmdtp, flag, --argc, ++argv);
+
+	return CMD_RET_USAGE;
+}
+
+U_BOOT_CMD(
+	gsc, 4, 1, do_gsc, "GSC configuration",
+	"[wd enable [30|60]]|[wd disable]\n"
+	);
 
 #endif /* CONFIG_CMD_GSC */

board/gateworks/gw_ventana/gsc.h

@@ -19,12 +19,15 @@ enum {
 	GSC_SC_CTRL0		= 0x00,
 	GSC_SC_CTRL1		= 0x01,
 	GSC_SC_STATUS		= 0x0a,
+	GSC_SC_FWCRC		= 0x0c,
 	GSC_SC_FWVER		= 0x0e,
 };
 
 /* System Controller Control1 bits */
 enum {
-	GSC_SC_CTRL1_WDDIS	= 7, /* 1 = disable watchdog */
+	GSC_SC_CTRL1_WDTIME	= 4, /* 1 = 60s timeout, 0 = 30s timeout */
+	GSC_SC_CTRL1_WDEN	= 5, /* 1 = enable, 0 = disable */
+	GSC_SC_CTRL1_WDDIS	= 7, /* 1 = disable boot watchdog */
 };
 
 /* System Controller Interrupt bits */
@@ -62,5 +65,6 @@ enum {
  */
 int gsc_i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len);
 int gsc_i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len);
+int gsc_info(int verbose);
 #endif
 

board/gateworks/gw_ventana/gw_ventana.c

@@ -1430,15 +1430,8 @@ int checkboard(void)
 		return 0;
 
 	/* Display GSC firmware revision/CRC/status */
-	i2c_set_bus_num(CONFIG_I2C_GSC);
-	if (!gsc_i2c_read(GSC_SC_ADDR, GSC_SC_FWVER, 1, buf, 1)) {
-		printf("GSC:   v%d", buf[0]);
-		if (!gsc_i2c_read(GSC_SC_ADDR, GSC_SC_STATUS, 1, buf, 4)) {
-			printf(" 0x%04x", buf[2] | buf[3]<<8); /* CRC */
-			printf(" 0x%02x", buf[0]); /* irq status */
-		}
-		puts("\n");
-	}
+	gsc_info(0);
+
 	/* Display RTC */
 	if (!gsc_i2c_read(GSC_RTC_ADDR, 0x00, 1, buf, 4)) {
 		printf("RTC:   %d\n",
@@ -1575,13 +1568,6 @@ int misc_init_r(void)
 	} else {
 		puts("Error: could not disable GSC Watchdog\n");
 	}
-	if (!gsc_i2c_read(GSC_SC_ADDR, GSC_SC_STATUS, 1, &reg, 1)) {
-		if (reg & (1 << GSC_SC_IRQ_WATCHDOG)) { /* watchdog timeout */
-			puts("GSC boot watchdog timeout detected\n");
-			reg &= ~(1 << GSC_SC_IRQ_WATCHDOG); /* clear flag */
-			gsc_i2c_write(GSC_SC_ADDR, GSC_SC_STATUS, 1, &reg, 1);
-		}
-	}
 
 	return 0;
 }