kbuild: rust: keep Rust objects out of Clang LTO with inline helpersgrafted

Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit
`objtool` errors such as:

    vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a:
    can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd

The reason is that in such builds, the Clang invocation that compiles
the combined Rust plus helpers bitcode emits LLVM bitcode (again) --
the final code generation happens in the linker's LTO step, which the
`-mllvm` trap options passed to Clang do not reach.

This, in turn, means that unreachable traps are missing, and the
impossible paths do not merely fallthrough to the next symbol, but past
the end of their own section, since LTO builds place each function in
its own section.

Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always
emits machine code directly, with the traps in place.

Assisted-by: LLM
Cc: Gary Guo <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

3 files changed, 568 insertions, 0 deletions

diff --git a/drivers/phy/mscc/Kconfig b/drivers/phy/mscc/Kconfig
new file mode 100644
index 000000000..83be16d39
--- /dev/null
+++ b/drivers/phy/mscc/Kconfig
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Microsemi devices
+#
+
+config PHY_OCELOT_SERDES
+	tristate "SerDes PHY driver for Microsemi Ocelot"
+	select GENERIC_PHY
+	depends on OF
+	depends on MFD_SYSCON
+	help
+	  Enable this for supporting SerDes muxing with Microsemi Ocelot.
diff --git a/drivers/phy/mscc/Makefile b/drivers/phy/mscc/Makefile
new file mode 100644
index 000000000..7bec61adb
--- /dev/null
+++ b/drivers/phy/mscc/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the Microsemi phy drivers.
+#
+
+obj-$(CONFIG_PHY_OCELOT_SERDES) := phy-ocelot-serdes.o
diff --git a/drivers/phy/mscc/phy-ocelot-serdes.c b/drivers/phy/mscc/phy-ocelot-serdes.c
new file mode 100644
index 000000000..1cd1b5db2
--- /dev/null
+++ b/drivers/phy/mscc/phy-ocelot-serdes.c
@@ -0,0 +1,550 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * SerDes PHY driver for Microsemi Ocelot
+ *
+ * Copyright (c) 2018 Microsemi
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/phy.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <soc/mscc/ocelot_hsio.h>
+#include <dt-bindings/phy/phy-ocelot-serdes.h>
+
+struct serdes_ctrl {
+	struct regmap		*regs;
+	struct device		*dev;
+	struct phy		*phys[SERDES_MAX];
+};
+
+struct serdes_macro {
+	u8			idx;
+	/* Not used when in QSGMII or PCIe mode */
+	int			port;
+	struct serdes_ctrl	*ctrl;
+};
+
+#define MCB_S6G_CFG_TIMEOUT     50
+
+static int __serdes_write_mcb_s6g(struct regmap *regmap, u8 macro, u32 op)
+{
+	unsigned int regval = 0;
+
+	regmap_write(regmap, HSIO_MCB_S6G_ADDR_CFG, op |
+		     HSIO_MCB_S6G_ADDR_CFG_SERDES6G_ADDR(BIT(macro)));
+
+	return regmap_read_poll_timeout(regmap, HSIO_MCB_S6G_ADDR_CFG, regval,
+					(regval & op) != op, 100,
+					MCB_S6G_CFG_TIMEOUT * 1000);
+}
+
+static int serdes_commit_mcb_s6g(struct regmap *regmap, u8 macro)
+{
+	return __serdes_write_mcb_s6g(regmap, macro,
+		HSIO_MCB_S6G_ADDR_CFG_SERDES6G_WR_ONE_SHOT);
+}
+
+static int serdes_update_mcb_s6g(struct regmap *regmap, u8 macro)
+{
+	return __serdes_write_mcb_s6g(regmap, macro,
+		HSIO_MCB_S6G_ADDR_CFG_SERDES6G_RD_ONE_SHOT);
+}
+
+static int serdes_init_s6g(struct regmap *regmap, u8 serdes, int mode)
+{
+	u32 pll_fsm_ctrl_data;
+	u32 ob_ena1v_mode;
+	u32 des_bw_ana;
+	u32 ob_ena_cas;
+	u32 if_mode;
+	u32 ob_lev;
+	u32 qrate;
+	int ret;
+
+	if (mode == PHY_INTERFACE_MODE_QSGMII) {
+		pll_fsm_ctrl_data = 120;
+		ob_ena1v_mode = 0;
+		ob_ena_cas = 0;
+		des_bw_ana = 5;
+		ob_lev = 24;
+		if_mode = 3;
+		qrate = 0;
+	} else {
+		pll_fsm_ctrl_data = 60;
+		ob_ena1v_mode = 1;
+		ob_ena_cas = 2;
+		des_bw_ana = 3;
+		ob_lev = 48;
+		if_mode = 1;
+		qrate = 1;
+	}
+
+	ret = serdes_update_mcb_s6g(regmap, serdes);
+	if (ret)
+		return ret;
+
+	/* Test pattern */
+
+	regmap_update_bits(regmap, HSIO_S6G_COMMON_CFG,
+			   HSIO_S6G_COMMON_CFG_SYS_RST, 0);
+
+	regmap_update_bits(regmap, HSIO_S6G_PLL_CFG,
+			   HSIO_S6G_PLL_CFG_PLL_FSM_ENA, 0);
+
+	regmap_update_bits(regmap, HSIO_S6G_IB_CFG,
+			   HSIO_S6G_IB_CFG_IB_SIG_DET_ENA |
+			   HSIO_S6G_IB_CFG_IB_REG_ENA |
+			   HSIO_S6G_IB_CFG_IB_SAM_ENA |
+			   HSIO_S6G_IB_CFG_IB_EQZ_ENA |
+			   HSIO_S6G_IB_CFG_IB_CONCUR |
+			   HSIO_S6G_IB_CFG_IB_CAL_ENA,
+			   HSIO_S6G_IB_CFG_IB_SIG_DET_ENA |
+			   HSIO_S6G_IB_CFG_IB_REG_ENA |
+			   HSIO_S6G_IB_CFG_IB_SAM_ENA |
+			   HSIO_S6G_IB_CFG_IB_EQZ_ENA |
+			   HSIO_S6G_IB_CFG_IB_CONCUR);
+
+	regmap_update_bits(regmap, HSIO_S6G_IB_CFG1,
+			   HSIO_S6G_IB_CFG1_IB_FRC_OFFSET |
+			   HSIO_S6G_IB_CFG1_IB_FRC_LP |
+			   HSIO_S6G_IB_CFG1_IB_FRC_MID |
+			   HSIO_S6G_IB_CFG1_IB_FRC_HP |
+			   HSIO_S6G_IB_CFG1_IB_FILT_OFFSET |
+			   HSIO_S6G_IB_CFG1_IB_FILT_LP |
+			   HSIO_S6G_IB_CFG1_IB_FILT_MID |
+			   HSIO_S6G_IB_CFG1_IB_FILT_HP,
+			   HSIO_S6G_IB_CFG1_IB_FILT_OFFSET |
+			   HSIO_S6G_IB_CFG1_IB_FILT_HP |
+			   HSIO_S6G_IB_CFG1_IB_FILT_LP |
+			   HSIO_S6G_IB_CFG1_IB_FILT_MID);
+
+	regmap_update_bits(regmap, HSIO_S6G_IB_CFG2,
+			   HSIO_S6G_IB_CFG2_IB_UREG_M,
+			   HSIO_S6G_IB_CFG2_IB_UREG(4));
+
+	regmap_update_bits(regmap, HSIO_S6G_IB_CFG3,
+			   HSIO_S6G_IB_CFG3_IB_INI_OFFSET_M |
+			   HSIO_S6G_IB_CFG3_IB_INI_LP_M |
+			   HSIO_S6G_IB_CFG3_IB_INI_MID_M |
+			   HSIO_S6G_IB_CFG3_IB_INI_HP_M,
+			   HSIO_S6G_IB_CFG3_IB_INI_OFFSET(31) |
+			   HSIO_S6G_IB_CFG3_IB_INI_LP(1) |
+			   HSIO_S6G_IB_CFG3_IB_INI_MID(31) |
+			   HSIO_S6G_IB_CFG3_IB_INI_HP(0));
+
+	regmap_update_bits(regmap, HSIO_S6G_MISC_CFG,
+			   HSIO_S6G_MISC_CFG_LANE_RST,
+			   HSIO_S6G_MISC_CFG_LANE_RST);
+
+	ret = serdes_commit_mcb_s6g(regmap, serdes);
+	if (ret)
+		return ret;
+
+	/* OB + DES + IB + SER CFG */
+	regmap_update_bits(regmap, HSIO_S6G_OB_CFG,
+			   HSIO_S6G_OB_CFG_OB_IDLE |
+			   HSIO_S6G_OB_CFG_OB_ENA1V_MODE |
+			   HSIO_S6G_OB_CFG_OB_POST0_M |
+			   HSIO_S6G_OB_CFG_OB_PREC_M,
+			   (ob_ena1v_mode ? HSIO_S6G_OB_CFG_OB_ENA1V_MODE : 0) |
+			   HSIO_S6G_OB_CFG_OB_POST0(0) |
+			   HSIO_S6G_OB_CFG_OB_PREC(0));
+
+	regmap_update_bits(regmap, HSIO_S6G_OB_CFG1,
+			   HSIO_S6G_OB_CFG1_OB_ENA_CAS_M |
+			   HSIO_S6G_OB_CFG1_OB_LEV_M,
+			   HSIO_S6G_OB_CFG1_OB_LEV(ob_lev) |
+			   HSIO_S6G_OB_CFG1_OB_ENA_CAS(ob_ena_cas));
+
+	regmap_update_bits(regmap, HSIO_S6G_DES_CFG,
+			   HSIO_S6G_DES_CFG_DES_PHS_CTRL_M |
+			   HSIO_S6G_DES_CFG_DES_CPMD_SEL_M |
+			   HSIO_S6G_DES_CFG_DES_BW_ANA_M,
+			   HSIO_S6G_DES_CFG_DES_PHS_CTRL(2) |
+			   HSIO_S6G_DES_CFG_DES_CPMD_SEL(0) |
+			   HSIO_S6G_DES_CFG_DES_BW_ANA(des_bw_ana));
+
+	regmap_update_bits(regmap, HSIO_S6G_IB_CFG,
+			   HSIO_S6G_IB_CFG_IB_SIG_DET_CLK_SEL_M |
+			   HSIO_S6G_IB_CFG_IB_REG_PAT_SEL_OFFSET_M,
+			   HSIO_S6G_IB_CFG_IB_REG_PAT_SEL_OFFSET(0) |
+			   HSIO_S6G_IB_CFG_IB_SIG_DET_CLK_SEL(0));
+
+	regmap_update_bits(regmap, HSIO_S6G_IB_CFG1,
+			   HSIO_S6G_IB_CFG1_IB_TSDET_M,
+			   HSIO_S6G_IB_CFG1_IB_TSDET(16));
+
+	regmap_update_bits(regmap, HSIO_S6G_SER_CFG,
+			   HSIO_S6G_SER_CFG_SER_ALISEL_M |
+			   HSIO_S6G_SER_CFG_SER_ENALI,
+			   HSIO_S6G_SER_CFG_SER_ALISEL(0));
+
+	regmap_update_bits(regmap, HSIO_S6G_PLL_CFG,
+			   HSIO_S6G_PLL_CFG_PLL_DIV4 |
+			   HSIO_S6G_PLL_CFG_PLL_ENA_ROT |
+			   HSIO_S6G_PLL_CFG_PLL_FSM_CTRL_DATA_M |
+			   HSIO_S6G_PLL_CFG_PLL_ROT_DIR |
+			   HSIO_S6G_PLL_CFG_PLL_ROT_FRQ,
+			   HSIO_S6G_PLL_CFG_PLL_FSM_CTRL_DATA
+			   (pll_fsm_ctrl_data));
+
+	regmap_update_bits(regmap, HSIO_S6G_COMMON_CFG,
+			   HSIO_S6G_COMMON_CFG_SYS_RST |
+			   HSIO_S6G_COMMON_CFG_ENA_LANE |
+			   HSIO_S6G_COMMON_CFG_PWD_RX |
+			   HSIO_S6G_COMMON_CFG_PWD_TX |
+			   HSIO_S6G_COMMON_CFG_HRATE |
+			   HSIO_S6G_COMMON_CFG_QRATE |
+			   HSIO_S6G_COMMON_CFG_ENA_ELOOP |
+			   HSIO_S6G_COMMON_CFG_ENA_FLOOP |
+			   HSIO_S6G_COMMON_CFG_IF_MODE_M,
+			   HSIO_S6G_COMMON_CFG_SYS_RST |
+			   HSIO_S6G_COMMON_CFG_ENA_LANE |
+			   (qrate ? HSIO_S6G_COMMON_CFG_QRATE : 0) |
+			   HSIO_S6G_COMMON_CFG_IF_MODE(if_mode));
+
+	regmap_update_bits(regmap, HSIO_S6G_MISC_CFG,
+			   HSIO_S6G_MISC_CFG_LANE_RST |
+			   HSIO_S6G_MISC_CFG_DES_100FX_CPMD_ENA |
+			   HSIO_S6G_MISC_CFG_RX_LPI_MODE_ENA |
+			   HSIO_S6G_MISC_CFG_TX_LPI_MODE_ENA,
+			   HSIO_S6G_MISC_CFG_LANE_RST |
+			   HSIO_S6G_MISC_CFG_RX_LPI_MODE_ENA);
+
+
+	ret = serdes_commit_mcb_s6g(regmap, serdes);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(regmap, HSIO_S6G_PLL_CFG,
+			   HSIO_S6G_PLL_CFG_PLL_FSM_ENA,
+			   HSIO_S6G_PLL_CFG_PLL_FSM_ENA);
+
+	ret = serdes_commit_mcb_s6g(regmap, serdes);
+	if (ret)
+		return ret;
+
+	/* Wait for PLL bringup */
+	msleep(20);
+
+	regmap_update_bits(regmap, HSIO_S6G_IB_CFG,
+			   HSIO_S6G_IB_CFG_IB_CAL_ENA,
+			   HSIO_S6G_IB_CFG_IB_CAL_ENA);
+
+	regmap_update_bits(regmap, HSIO_S6G_MISC_CFG,
+			   HSIO_S6G_MISC_CFG_LANE_RST, 0);
+
+	ret = serdes_commit_mcb_s6g(regmap, serdes);
+	if (ret)
+		return ret;
+
+	/* Wait for calibration */
+	msleep(60);
+
+	regmap_update_bits(regmap, HSIO_S6G_IB_CFG,
+			   HSIO_S6G_IB_CFG_IB_REG_PAT_SEL_OFFSET_M |
+			   HSIO_S6G_IB_CFG_IB_SIG_DET_CLK_SEL_M,
+			   HSIO_S6G_IB_CFG_IB_REG_PAT_SEL_OFFSET(0) |
+			   HSIO_S6G_IB_CFG_IB_SIG_DET_CLK_SEL(7));
+
+	regmap_update_bits(regmap, HSIO_S6G_IB_CFG1,
+			   HSIO_S6G_IB_CFG1_IB_TSDET_M,
+			   HSIO_S6G_IB_CFG1_IB_TSDET(3));
+
+	/* IB CFG */
+
+	return 0;
+}
+
+#define MCB_S1G_CFG_TIMEOUT     50
+
+static int __serdes_write_mcb_s1g(struct regmap *regmap, u8 macro, u32 op)
+{
+	unsigned int regval;
+
+	regmap_write(regmap, HSIO_MCB_S1G_ADDR_CFG, op |
+		     HSIO_MCB_S1G_ADDR_CFG_SERDES1G_ADDR(BIT(macro)));
+
+	return regmap_read_poll_timeout(regmap, HSIO_MCB_S1G_ADDR_CFG, regval,
+					(regval & op) != op, 100,
+					MCB_S1G_CFG_TIMEOUT * 1000);
+}
+
+static int serdes_commit_mcb_s1g(struct regmap *regmap, u8 macro)
+{
+	return __serdes_write_mcb_s1g(regmap, macro,
+		HSIO_MCB_S1G_ADDR_CFG_SERDES1G_WR_ONE_SHOT);
+}
+
+static int serdes_update_mcb_s1g(struct regmap *regmap, u8 macro)
+{
+	return __serdes_write_mcb_s1g(regmap, macro,
+		HSIO_MCB_S1G_ADDR_CFG_SERDES1G_RD_ONE_SHOT);
+}
+
+static int serdes_init_s1g(struct regmap *regmap, u8 serdes)
+{
+	int ret;
+
+	ret = serdes_update_mcb_s1g(regmap, serdes);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(regmap, HSIO_S1G_COMMON_CFG,
+			   HSIO_S1G_COMMON_CFG_SYS_RST |
+			   HSIO_S1G_COMMON_CFG_ENA_LANE |
+			   HSIO_S1G_COMMON_CFG_ENA_ELOOP |
+			   HSIO_S1G_COMMON_CFG_ENA_FLOOP,
+			   HSIO_S1G_COMMON_CFG_ENA_LANE);
+
+	regmap_update_bits(regmap, HSIO_S1G_PLL_CFG,
+			   HSIO_S1G_PLL_CFG_PLL_FSM_ENA |
+			   HSIO_S1G_PLL_CFG_PLL_FSM_CTRL_DATA_M,
+			   HSIO_S1G_PLL_CFG_PLL_FSM_CTRL_DATA(200) |
+			   HSIO_S1G_PLL_CFG_PLL_FSM_ENA);
+
+	regmap_update_bits(regmap, HSIO_S1G_MISC_CFG,
+			   HSIO_S1G_MISC_CFG_DES_100FX_CPMD_ENA |
+			   HSIO_S1G_MISC_CFG_LANE_RST,
+			   HSIO_S1G_MISC_CFG_LANE_RST);
+
+	ret = serdes_commit_mcb_s1g(regmap, serdes);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(regmap, HSIO_S1G_COMMON_CFG,
+			   HSIO_S1G_COMMON_CFG_SYS_RST,
+			   HSIO_S1G_COMMON_CFG_SYS_RST);
+
+	regmap_update_bits(regmap, HSIO_S1G_MISC_CFG,
+			   HSIO_S1G_MISC_CFG_LANE_RST, 0);
+
+	ret = serdes_commit_mcb_s1g(regmap, serdes);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+struct serdes_mux {
+	u8			idx;
+	u8			port;
+	enum phy_mode		mode;
+	int			submode;
+	u32			mask;
+	u32			mux;
+};
+
+#define SERDES_MUX(_idx, _port, _mode, _submode, _mask, _mux) { \
+	.idx = _idx,						\
+	.port = _port,						\
+	.mode = _mode,						\
+	.submode = _submode,					\
+	.mask = _mask,						\
+	.mux = _mux,						\
+}
+
+#define SERDES_MUX_SGMII(i, p, m, c) \
+	SERDES_MUX(i, p, PHY_MODE_ETHERNET, PHY_INTERFACE_MODE_SGMII, m, c)
+#define SERDES_MUX_QSGMII(i, p, m, c) \
+	SERDES_MUX(i, p, PHY_MODE_ETHERNET, PHY_INTERFACE_MODE_QSGMII, m, c)
+
+static const struct serdes_mux ocelot_serdes_muxes[] = {
+	SERDES_MUX_SGMII(SERDES1G(0), 0, 0, 0),
+	SERDES_MUX_SGMII(SERDES1G(1), 1, HSIO_HW_CFG_DEV1G_5_MODE, 0),
+	SERDES_MUX_SGMII(SERDES1G(1), 5, HSIO_HW_CFG_QSGMII_ENA |
+			 HSIO_HW_CFG_DEV1G_5_MODE, HSIO_HW_CFG_DEV1G_5_MODE),
+	SERDES_MUX_SGMII(SERDES1G(2), 2, HSIO_HW_CFG_DEV1G_4_MODE, 0),
+	SERDES_MUX_SGMII(SERDES1G(2), 4, HSIO_HW_CFG_QSGMII_ENA |
+			 HSIO_HW_CFG_DEV1G_4_MODE, HSIO_HW_CFG_DEV1G_4_MODE),
+	SERDES_MUX_SGMII(SERDES1G(3), 3, HSIO_HW_CFG_DEV1G_6_MODE, 0),
+	SERDES_MUX_SGMII(SERDES1G(3), 6, HSIO_HW_CFG_QSGMII_ENA |
+			 HSIO_HW_CFG_DEV1G_6_MODE, HSIO_HW_CFG_DEV1G_6_MODE),
+	SERDES_MUX_SGMII(SERDES1G(4), 4, HSIO_HW_CFG_QSGMII_ENA |
+			 HSIO_HW_CFG_DEV1G_4_MODE | HSIO_HW_CFG_DEV1G_9_MODE,
+			 0),
+	SERDES_MUX_SGMII(SERDES1G(4), 9, HSIO_HW_CFG_DEV1G_4_MODE |
+			 HSIO_HW_CFG_DEV1G_9_MODE, HSIO_HW_CFG_DEV1G_4_MODE |
+			 HSIO_HW_CFG_DEV1G_9_MODE),
+	SERDES_MUX_SGMII(SERDES1G(5), 5, HSIO_HW_CFG_QSGMII_ENA |
+			 HSIO_HW_CFG_DEV1G_5_MODE | HSIO_HW_CFG_DEV2G5_10_MODE,
+			 0),
+	SERDES_MUX_SGMII(SERDES1G(5), 10, HSIO_HW_CFG_PCIE_ENA |
+			 HSIO_HW_CFG_DEV1G_5_MODE | HSIO_HW_CFG_DEV2G5_10_MODE,
+			 HSIO_HW_CFG_DEV1G_5_MODE | HSIO_HW_CFG_DEV2G5_10_MODE),
+	SERDES_MUX_QSGMII(SERDES6G(0), 4, HSIO_HW_CFG_QSGMII_ENA,
+			  HSIO_HW_CFG_QSGMII_ENA),
+	SERDES_MUX_QSGMII(SERDES6G(0), 5, HSIO_HW_CFG_QSGMII_ENA,
+			  HSIO_HW_CFG_QSGMII_ENA),
+	SERDES_MUX_QSGMII(SERDES6G(0), 6, HSIO_HW_CFG_QSGMII_ENA,
+			  HSIO_HW_CFG_QSGMII_ENA),
+	SERDES_MUX_SGMII(SERDES6G(0), 7, HSIO_HW_CFG_QSGMII_ENA, 0),
+	SERDES_MUX_QSGMII(SERDES6G(0), 7, HSIO_HW_CFG_QSGMII_ENA,
+			  HSIO_HW_CFG_QSGMII_ENA),
+	SERDES_MUX_SGMII(SERDES6G(1), 8, 0, 0),
+	SERDES_MUX_SGMII(SERDES6G(2), 10, HSIO_HW_CFG_PCIE_ENA |
+			 HSIO_HW_CFG_DEV2G5_10_MODE, 0),
+	SERDES_MUX(SERDES6G(2), 10, PHY_MODE_PCIE, 0, HSIO_HW_CFG_PCIE_ENA,
+		   HSIO_HW_CFG_PCIE_ENA),
+};
+
+static int serdes_set_mode(struct phy *phy, enum phy_mode mode, int submode)
+{
+	struct serdes_macro *macro = phy_get_drvdata(phy);
+	unsigned int i;
+	int ret;
+
+	/* As of now only PHY_MODE_ETHERNET is supported */
+	if (mode != PHY_MODE_ETHERNET)
+		return -EOPNOTSUPP;
+
+	for (i = 0; i < ARRAY_SIZE(ocelot_serdes_muxes); i++) {
+		if (macro->idx != ocelot_serdes_muxes[i].idx ||
+		    mode != ocelot_serdes_muxes[i].mode ||
+		    submode != ocelot_serdes_muxes[i].submode)
+			continue;
+
+		if (submode != PHY_INTERFACE_MODE_QSGMII &&
+		    macro->port != ocelot_serdes_muxes[i].port)
+			continue;
+
+		ret = regmap_update_bits(macro->ctrl->regs, HSIO_HW_CFG,
+					 ocelot_serdes_muxes[i].mask,
+					 ocelot_serdes_muxes[i].mux);
+		if (ret)
+			return ret;
+
+		if (macro->idx <= SERDES1G_MAX)
+			return serdes_init_s1g(macro->ctrl->regs, macro->idx);
+		else if (macro->idx <= SERDES6G_MAX)
+			return serdes_init_s6g(macro->ctrl->regs,
+					       macro->idx - (SERDES1G_MAX + 1),
+					       ocelot_serdes_muxes[i].submode);
+
+		/* PCIe not supported yet */
+		return -EOPNOTSUPP;
+	}
+
+	return -EINVAL;
+}
+
+static const struct phy_ops serdes_ops = {
+	.set_mode	= serdes_set_mode,
+	.owner		= THIS_MODULE,
+};
+
+static struct phy *serdes_simple_xlate(struct device *dev,
+				       const struct of_phandle_args *args)
+{
+	struct serdes_ctrl *ctrl = dev_get_drvdata(dev);
+	unsigned int port, idx, i;
+
+	if (args->args_count != 2)
+		return ERR_PTR(-EINVAL);
+
+	port = args->args[0];
+	idx = args->args[1];
+
+	for (i = 0; i < SERDES_MAX; i++) {
+		struct serdes_macro *macro = phy_get_drvdata(ctrl->phys[i]);
+
+		if (idx != macro->idx)
+			continue;
+
+		/* SERDES6G(0) is the only SerDes capable of QSGMII */
+		if (idx != SERDES6G(0) && macro->port >= 0)
+			return ERR_PTR(-EBUSY);
+
+		macro->port = port;
+		return ctrl->phys[i];
+	}
+
+	return ERR_PTR(-ENODEV);
+}
+
+static int serdes_phy_create(struct serdes_ctrl *ctrl, u8 idx, struct phy **phy)
+{
+	struct serdes_macro *macro;
+
+	*phy = devm_phy_create(ctrl->dev, NULL, &serdes_ops);
+	if (IS_ERR(*phy))
+		return PTR_ERR(*phy);
+
+	macro = devm_kzalloc(ctrl->dev, sizeof(*macro), GFP_KERNEL);
+	if (!macro)
+		return -ENOMEM;
+
+	macro->idx = idx;
+	macro->ctrl = ctrl;
+	macro->port = -1;
+
+	phy_set_drvdata(*phy, macro);
+
+	return 0;
+}
+
+static int serdes_probe(struct platform_device *pdev)
+{
+	struct phy_provider *provider;
+	struct serdes_ctrl *ctrl;
+	struct resource *res;
+	unsigned int i;
+	int ret;
+
+	ctrl = devm_kzalloc(&pdev->dev, sizeof(*ctrl), GFP_KERNEL);
+	if (!ctrl)
+		return -ENOMEM;
+
+	ctrl->dev = &pdev->dev;
+	ctrl->regs = syscon_node_to_regmap(pdev->dev.parent->of_node);
+	if (IS_ERR(ctrl->regs)) {
+		/* Fall back to using IORESOURCE_REG, if possible */
+		res = platform_get_resource(pdev, IORESOURCE_REG, 0);
+		if (res)
+			ctrl->regs = dev_get_regmap(ctrl->dev->parent,
+						    res->name);
+	}
+
+	if (IS_ERR(ctrl->regs))
+		return PTR_ERR(ctrl->regs);
+
+	for (i = 0; i < SERDES_MAX; i++) {
+		ret = serdes_phy_create(ctrl, i, &ctrl->phys[i]);
+		if (ret)
+			return ret;
+	}
+
+	dev_set_drvdata(&pdev->dev, ctrl);
+
+	provider = devm_of_phy_provider_register(ctrl->dev,
+						 serdes_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(provider);
+}
+
+static const struct of_device_id serdes_ids[] = {
+	{ .compatible = "mscc,vsc7514-serdes", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, serdes_ids);
+
+static struct platform_driver mscc_ocelot_serdes = {
+	.probe		= serdes_probe,
+	.driver		= {
+		.name	= "mscc,ocelot-serdes",
+		.of_match_table = of_match_ptr(serdes_ids),
+	},
+};
+
+module_platform_driver(mscc_ocelot_serdes);
+
+MODULE_AUTHOR("Quentin Schulz <quentin.schulz@bootlin.com>");
+MODULE_DESCRIPTION("SerDes driver for Microsemi Ocelot");
+MODULE_LICENSE("Dual MIT/GPL");