imx: ventana: add econfig command

The Gateworks Ventana EEPROM contains a set of configuration bits that
affect the removal of device-tree nodes that support peripherals that do not
exist on sub-loaded boards. This patch adds:
 - a structure to define a config bit name, dt node alias, bit position
 - an array of supported configuration items
 - an econfig command to get/set/list configuration bits
 - use of the array when adjusting the FDT prior to boot

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
diff --git a/board/gateworks/gw_ventana/eeprom.c b/board/gateworks/gw_ventana/eeprom.c
index e90186e..3edc915 100644
--- a/board/gateworks/gw_ventana/eeprom.c
+++ b/board/gateworks/gw_ventana/eeprom.c
@@ -6,7 +6,10 @@
  */
 
 #include <common.h>
+#include <errno.h>
 #include <i2c.h>
+#include <malloc.h>
+#include <asm/bitops.h>
 
 #include "gsc.h"
 #include "ventana_eeprom.h"
@@ -38,14 +41,12 @@
 	/* read eeprom config section */
 	if (gsc_i2c_read(GSC_EEPROM_ADDR, 0x00, 1, buf, sizeof(*info))) {
 		puts("EEPROM: Failed to read EEPROM\n");
-		info->model[0] = 0;
 		return GW_UNKNOWN;
 	}
 
 	/* sanity checks */
 	if (info->model[0] != 'G' || info->model[1] != 'W') {
 		puts("EEPROM: Invalid Model in EEPROM\n");
-		info->model[0] = 0;
 		return GW_UNKNOWN;
 	}
 
@@ -55,7 +56,6 @@
 	if ((info->chksum[0] != chksum>>8) ||
 	    (info->chksum[1] != (chksum&0xff))) {
 		puts("EEPROM: Failed EEPROM checksum\n");
-		info->model[0] = 0;
 		return GW_UNKNOWN;
 	}
 
@@ -87,3 +87,165 @@
 	}
 	return type;
 }
+
+/* list of config bits that the bootloader will remove from dtb if not set */
+struct ventana_eeprom_config econfig[] = {
+	{ "eth0", "ethernet0", EECONFIG_ETH0 },
+	{ "eth1", "ethernet1", EECONFIG_ETH1 },
+	{ "sata", "ahci0", EECONFIG_SATA },
+	{ "pcie", NULL, EECONFIG_PCIE},
+	{ "lvds0", NULL, EECONFIG_LVDS0 },
+	{ "lvds1", NULL, EECONFIG_LVDS1 },
+	{ "usb0", NULL, EECONFIG_USB0 },
+	{ "usb1", NULL, EECONFIG_USB1 },
+	{ "mmc0", NULL, EECONFIG_SD0 },
+	{ "mmc1", NULL, EECONFIG_SD1 },
+	{ "mmc2", NULL, EECONFIG_SD2 },
+	{ "mmc3", NULL, EECONFIG_SD3 },
+	{ "uart0", NULL, EECONFIG_UART0 },
+	{ "uart1", NULL, EECONFIG_UART1 },
+	{ "uart2", NULL, EECONFIG_UART2 },
+	{ "uart3", NULL, EECONFIG_UART3 },
+	{ "uart4", NULL, EECONFIG_UART4 },
+	{ "ipu0", NULL, EECONFIG_IPU0 },
+	{ "ipu1", NULL, EECONFIG_IPU1 },
+	{ "can0", NULL, EECONFIG_FLEXCAN },
+	{ "i2c0", NULL, EECONFIG_I2C0 },
+	{ "i2c1", NULL, EECONFIG_I2C1 },
+	{ "i2c2", NULL, EECONFIG_I2C2 },
+	{ "vpu", NULL, EECONFIG_VPU },
+	{ "csi0", NULL, EECONFIG_CSI0 },
+	{ "csi1", NULL, EECONFIG_CSI1 },
+	{ "spi0", NULL, EECONFIG_ESPCI0 },
+	{ "spi1", NULL, EECONFIG_ESPCI1 },
+	{ "spi2", NULL, EECONFIG_ESPCI2 },
+	{ "spi3", NULL, EECONFIG_ESPCI3 },
+	{ "spi4", NULL, EECONFIG_ESPCI4 },
+	{ "spi5", NULL, EECONFIG_ESPCI5 },
+	{ "gps", "pps", EECONFIG_GPS },
+	{ "hdmi_in", NULL, EECONFIG_HDMI_IN },
+	{ "hdmi_out", NULL, EECONFIG_HDMI_OUT },
+	{ "cvbs_in", NULL, EECONFIG_VID_IN },
+	{ "cvbs_out", NULL, EECONFIG_VID_OUT },
+	{ "nand", NULL, EECONFIG_NAND },
+	{ /* Sentinel */ }
+};
+
+#ifdef CONFIG_CMD_EECONFIG
+static struct ventana_eeprom_config *get_config(const char *name)
+{
+	struct ventana_eeprom_config *cfg = econfig;
+
+	while (cfg->name) {
+		if (0 == strcmp(name, cfg->name))
+			return cfg;
+		cfg++;
+	}
+	return NULL;
+}
+
+static u8 econfig_bytes[sizeof(ventana_info.config)];
+static int econfig_init = -1;
+
+int do_econfig(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	struct ventana_eeprom_config *cfg;
+	struct ventana_board_info *info = &ventana_info;
+	int i;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	/* initialize */
+	if (econfig_init != 1) {
+		memcpy(econfig_bytes, info->config, sizeof(econfig_bytes));
+		econfig_init = 1;
+	}
+
+	/* list configs */
+	if ((strncmp(argv[1], "list", 4) == 0)) {
+		cfg = econfig;
+		while (cfg->name) {
+			printf("%s: %d\n", cfg->name,
+			       test_bit(cfg->bit, econfig_bytes) ?  1 : 0);
+			cfg++;
+		}
+	}
+
+	/* save */
+	else if ((strncmp(argv[1], "save", 4) == 0)) {
+		unsigned char *buf = (unsigned char *)info;
+		int chksum;
+
+		/* calculate new checksum */
+		memcpy(info->config, econfig_bytes, sizeof(econfig_bytes));
+		for (chksum = 0, i = 0; i < sizeof(*info)-2; i++)
+			chksum += buf[i];
+		debug("old chksum:0x%04x\n",
+		      (info->chksum[0] << 8) | info->chksum[1]);
+		debug("new chksum:0x%04x\n", chksum);
+		info->chksum[0] = chksum >> 8;
+		info->chksum[1] = chksum & 0xff;
+
+		/* write new config data */
+		if (gsc_i2c_write(GSC_EEPROM_ADDR, info->config - (u8 *)info,
+				  1, econfig_bytes, sizeof(econfig_bytes))) {
+			printf("EEPROM: Failed updating config\n");
+			return CMD_RET_FAILURE;
+		}
+
+		/* write new config data */
+		if (gsc_i2c_write(GSC_EEPROM_ADDR, info->chksum - (u8 *)info,
+				  1, info->chksum, 2)) {
+			printf("EEPROM: Failed updating checksum\n");
+			return CMD_RET_FAILURE;
+		}
+
+		printf("Config saved to EEPROM\n");
+	}
+
+	/* get config */
+	else if (argc == 2) {
+		cfg = get_config(argv[1]);
+		if (cfg) {
+			printf("%s: %d\n", cfg->name,
+			       test_bit(cfg->bit, econfig_bytes) ? 1 : 0);
+		} else {
+			printf("invalid config: %s\n", argv[1]);
+			return CMD_RET_FAILURE;
+		}
+	}
+
+	/* set config */
+	else if (argc == 3) {
+		cfg = get_config(argv[1]);
+		if (cfg) {
+			if (simple_strtol(argv[2], NULL, 10)) {
+				test_and_set_bit(cfg->bit, econfig_bytes);
+				printf("Enabled %s\n", cfg->name);
+			} else {
+				test_and_clear_bit(cfg->bit, econfig_bytes);
+				printf("Disabled %s\n", cfg->name);
+			}
+		} else {
+			printf("invalid config: %s\n", argv[1]);
+			return CMD_RET_FAILURE;
+		}
+	}
+
+	else
+		return CMD_RET_USAGE;
+
+	return CMD_RET_SUCCESS;
+}
+
+U_BOOT_CMD(
+	econfig, 3, 0, do_econfig,
+	"EEPROM configuration",
+	"list - list config\n"
+	"save - save config to EEPROM\n"
+	"<name> - get config 'name'\n"
+	"<name> [0|1] - set config 'name' to value\n"
+);
+
+#endif /* CONFIG_CMD_EECONFIG */