platform: mellanox: Add field upgrade capability register

Add new register to indicate the method of FPGA/CPLD field upgrade
supported on the specific system.
Currently two masks are available:
b00 - field upgrade through LPC gateway (new method introduced to
      accelerate field upgrade process).
b11 - field upgrade through CPU GPIO pins (old method).
Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: Michael Shych <michaelsh@nvidia.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230822113451.13785-3-vadimp@nvidia.comSigned-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/mlx-platform.c

@@ -62,6 +62,7 @@
 #define MLXPLAT_CPLD_LPC_REG_PWM_CONTROL_OFFSET	0x37
 #define MLXPLAT_CPLD_LPC_REG_AGGR_OFFSET	0x3a
 #define MLXPLAT_CPLD_LPC_REG_AGGR_MASK_OFFSET	0x3b
+#define MLXPLAT_CPLD_LPC_REG_FU_CAP_OFFSET	0x3c
 #define MLXPLAT_CPLD_LPC_REG_AGGRLO_OFFSET	0x40
 #define MLXPLAT_CPLD_LPC_REG_AGGRLO_MASK_OFFSET	0x41
 #define MLXPLAT_CPLD_LPC_REG_AGGRCO_OFFSET	0x42
@@ -236,6 +237,7 @@
 #define MLXPLAT_CPLD_VOLTREG_UPD_MASK	GENMASK(5, 4)
 #define MLXPLAT_CPLD_GWP_MASK		GENMASK(0, 0)
 #define MLXPLAT_CPLD_EROT_MASK		GENMASK(1, 0)
+#define MLXPLAT_CPLD_FU_CAP_MASK	GENMASK(1, 0)
 #define MLXPLAT_CPLD_PWR_BUTTON_MASK	BIT(0)
 #define MLXPLAT_CPLD_LATCH_RST_MASK	BIT(6)
 #define MLXPLAT_CPLD_THERMAL1_PDB_MASK	BIT(3)
@@ -3680,6 +3682,13 @@ static struct mlxreg_core_data mlxplat_mlxcpld_default_ng_regs_io_data[] = {
 		.mask = GENMASK(7, 0) & ~BIT(6),
 		.mode = 0200,
 	},
+	{
+		.label = "jtag_cap",
+		.reg = MLXPLAT_CPLD_LPC_REG_FU_CAP_OFFSET,
+		.mask = MLXPLAT_CPLD_FU_CAP_MASK,
+		.bit = 1,
+		.mode = 0444,
+	},
 	{
 		.label = "jtag_enable",
 		.reg = MLXPLAT_CPLD_LPC_REG_GP2_OFFSET,
@@ -4935,6 +4944,7 @@ static bool mlxplat_mlxcpld_writeable_reg(struct device *dev, unsigned int reg)
 	case MLXPLAT_CPLD_LPC_SAFE_BIOS_OFFSET:
 	case MLXPLAT_CPLD_LPC_SAFE_BIOS_WP_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_AGGR_MASK_OFFSET:
+	case MLXPLAT_CPLD_LPC_REG_FU_CAP_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_DBG1_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_DBG2_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_DBG3_OFFSET:
@@ -5046,6 +5056,7 @@ static bool mlxplat_mlxcpld_readable_reg(struct device *dev, unsigned int reg)
 	case MLXPLAT_CPLD_LPC_SAFE_BIOS_WP_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_AGGR_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_AGGR_MASK_OFFSET:
+	case MLXPLAT_CPLD_LPC_REG_FU_CAP_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_DBG1_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_DBG2_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_DBG3_OFFSET:
@@ -5203,6 +5214,7 @@ static bool mlxplat_mlxcpld_volatile_reg(struct device *dev, unsigned int reg)
 	case MLXPLAT_CPLD_LPC_SAFE_BIOS_WP_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_AGGR_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_AGGR_MASK_OFFSET:
+	case MLXPLAT_CPLD_LPC_REG_FU_CAP_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_DBG1_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_DBG2_OFFSET:
 	case MLXPLAT_CPLD_LPC_REG_DBG3_OFFSET: