The implementation of FW_LOADER requires CMDLINE to be enabled, and
expressses this. In order to not have to have every users also depends
on CMDLINE introduce SUPPORTS_FW_LOADER. This depends on CMDLINE and
ENV_SUPPORT and then we have all users depends on SUPPORTS_FW_LOADER.

Signed-off-by: Tom Rini <trini@konsulko.com>

The script based firmware loader does not use anything from the
fs_loader implementation. Separate it into its own library source
file and convert the mediatek PHY to use this separate code. This
should reduce the amount of code that is pulled in alongside the
firmware loader, as the FS loader is no longer included.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

Use plain buffer pointer in request_firmware_into_buf_via_script()
instead of a pointer to pointer. The later is not necessary as the
request_firmware_into_buf_via_script() does not modify the buffer
pointer. Update the mediatek driver to match.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: Weijie Gao <weijie.gao@mediatek.com>

Weijie Gao <weijie.gao@mediatek.com> says:

This patch adds PHY driver for MediaTek MT7987/MT7988 built-in 2.5Gb
ethernet PHY.

[trini: Change 'tristate' Kconfig to 'bool']

Link: https://lore.kernel.org/r/cover.1757315849.git.weijie.gao@mediatek.com

The MediaTek MT7987/MT7988 SoCs features a built-in 2.5Gb PHY
connected to GMAC1. The PHY supports 10/100/1000/2500 Mbps
full-duplex only.

The PHY requires one or two firmware files. Firmware for MT7988 has
already been added to upstream: mediatek/mt7988/i2p5ge-phy-pmb.bin.
MT7987 has two firmware files which will be add to upstream later:
i2p5ge-phy-pmb.bin and i2p5ge-phy-DSPBitTb.bin.

Environment variable can be set for firmware data loading:
mt7987_i2p5ge_load_pmb_firmware for i2p5ge-phy-pmb.bin
mt7987_i2p5ge_load_dspbit_firmware for i2p5ge-phy-DSPBitTb.bin
mt7988_i2p5ge_load_pmb_firmware for i2p5ge-phy-pmb.bin

This driver allows dedicated weak functions to be overridden by
board to provide the firmware data:
mt7987_i2p5ge_get_fw() for MT7987
mt7988_i2p5ge_get_fw() for MT7988

To enable the PHY, add the following not to device tree:
&eth1 {
	status = "okay";
	phy-mode = "xgmii";
	phy-handle = <&phy15>;

	phy15: ethernet-phy@15 {
		compatible = "ethernet-phy-ieee802.3-c45";
		reg = <15>;
		phy-mode = "xgmii";
	};
};

Signed-off-by: Sky Huang <SkyLake.Huang@mediatek.com>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>