feat(nxp-drivers): add Linflex driver

This is a UART controller found on NXP automotive parts.
For instance: S32V, S32G and S32R.

Change-Id: Iff0dd0c379633ac0651e5db287537c87666b57d2
Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
diff --git a/drivers/nxp/console/console.mk b/drivers/nxp/console/console.mk
index 6174650..5f3c6e3 100644
--- a/drivers/nxp/console/console.mk
+++ b/drivers/nxp/console/console.mk
@@ -1,5 +1,5 @@
 #
-# Copyright 2021 NXP
+# Copyright 2021-2024 NXP
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -28,8 +28,13 @@
 CONSOLE_SOURCES		:=	drivers/arm/pl011/aarch64/pl011_console.S	\
 				${PLAT_DRIVERS_PATH}/console/console_pl011.c
 else
+ifeq ($(CONSOLE), LINFLEX)
+CONSOLE_SOURCES		:=	${PLAT_DRIVERS_PATH}/console/linflex_console.S
+else
 	$(error -> CONSOLE not set!)
 endif
+
+endif
 endif
 
 ifeq (${BL_COMM_CONSOLE_NEEDED},yes)
diff --git a/drivers/nxp/console/linflex_console.S b/drivers/nxp/console/linflex_console.S
new file mode 100644
index 0000000..abcbb59
--- /dev/null
+++ b/drivers/nxp/console/linflex_console.S
@@ -0,0 +1,259 @@
+/*
+ * Copyright 2024 NXP
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <lib/libc/errno.h>
+
+#include <asm_macros.S>
+#include <console_macros.S>
+#include <lib/utils_def.h>
+
+#define LDIV_MULTIPLIER		U(16)
+
+#define LINFLEX_LINCR1		(0x0)
+#define LINCR1_INIT		BIT_32(0)
+#define LINCR1_MME		BIT_32(4)
+
+#define LINFLEX_LINSR		(0x8)
+#define LINSR_LINS_INITMODE	(0x00001000)
+#define LINSR_LINS_MASK		(0x0000F000)
+
+#define LINFLEX_UARTCR		(0x10)
+#define UARTCR_ROSE		BIT_32(23)
+
+#define LINFLEX_UARTSR		(0x14)
+#define LINFLEX_LINIBRR		(0x28)
+#define LINFLEX_LINFBRR		(0x24)
+#define LINFLEX_BDRL		(0x38)
+#define LINFLEX_UARTPTO		(0x50)
+
+#define UARTCR_UART		BIT_32(0)
+#define UARTCR_WL0		BIT_32(1)
+#define UARTCR_PC0		BIT_32(3)
+#define UARTCR_TXEN		BIT_32(4)
+#define UARTCR_RXEN		BIT_32(5)
+#define UARTCR_PC1		BIT_32(6)
+#define UARTCR_TFBM		BIT_32(8)
+#define UARTCR_RFBM		BIT_32(9)
+#define UARTCR_OSR_SHIFT	U(24)
+#define UARTCR_OSR_WIDTH	U(4)
+
+#define UARTSR_DTF		BIT_32(1)
+
+/*
+ * "core" functions are low-level implementations that do not require
+ * writable memory and are thus safe to call in BL1 crash context.
+ */
+.globl console_linflex_core_init
+.globl console_linflex_core_putc
+
+.globl console_linflex_register
+.globl console_linflex_putc
+
+/**
+ * uint32_t get_ldiv_mult(uintptr_t baseaddr, uint32_t clock,
+ *                        uint32_t baud, console_t *console,);
+ *
+ * Clobber list : x0 - x6
+ * Out x4: LDIV multiplier
+ */
+func get_ldiv_mult
+	ldr	w4, [x0, LINFLEX_UARTCR]
+	mov	w5, w4
+
+	/* Prepare choices in w5 and w6 */
+	ubfx	x5, x5, #UARTCR_OSR_SHIFT, #UARTCR_OSR_WIDTH
+	mov	w6, #LDIV_MULTIPLIER
+
+	and	w4, w4, #UARTCR_ROSE
+	cmp	w4, #0x0
+	csel	w4, w5, w6, ne
+	ret
+endfunc get_ldiv_mult
+
+/*
+ * void linflex_set_brg(uintptr_t baseaddr, uint32_t clock
+ *                      uint32_t baud, console_t *console);
+ *
+ * Clobber list : x0 - x7, x13
+ */
+func linflex_set_brg
+	mov	x13, x30
+	bl	get_ldiv_mult
+	mov	x30, x13
+
+	/* (x4) dividr = baudrate * ldiv_mult */
+	mul	x4, x4, x2
+	/* (x5) divisr = clock rate */
+	mov	x5, x1
+	/* (x6) ibr = divisr / dividr */
+	udiv	x6, x5, x4
+	/* (x7) fbr = divisr % dividr */
+	msub	x7, x6, x4, x5
+	/* fbr *= 16 / dividr */
+	lsl	x7, x7, #4
+	udiv	x7, x7, x4
+	/* fbr &= 0xf */
+	and	w7, w7, #0xf
+	str	w6, [x0, LINFLEX_LINIBRR]
+	str	w7, [x0, LINFLEX_LINFBRR]
+	ret
+endfunc linflex_set_brg
+
+/**
+ * int console_linflex_core_init(uintptr_t baseaddr, uint32_t clock,
+ *                               uint32_t baud);
+ *
+ * In:  x0 - Linflex base address
+ *      x1 - clock frequency
+ *      x2 - baudrate
+ * Out: x0 - 1 on success, 0 on error
+ * Clobber list : x0 - x7, x13 - x14
+ */
+func console_linflex_core_init
+	/* Set master mode and init mode */
+	mov	w4, #(LINCR1_INIT)
+	str	w4, [x0, LINFLEX_LINCR1]
+	mov	w4, #(LINCR1_MME | LINCR1_INIT)
+	str	w4, [x0, LINFLEX_LINCR1]
+
+	/* wait for init mode entry */
+wait_init_entry:
+	ldr	w4, [x0, LINFLEX_LINSR]
+	and	w4, w4, #LINSR_LINS_MASK
+	cmp	w4, #LINSR_LINS_INITMODE
+	b.ne	wait_init_entry
+
+	/* Set UART bit */
+	mov	w4, #UARTCR_UART
+	str	w4, [x0, LINFLEX_UARTCR]
+
+	mov	x14, x30
+	bl	linflex_set_brg
+	mov	x30, x14
+
+	/* Set preset timeout register value. */
+	mov	w4, #0xf
+	str	w4, [x0, LINFLEX_UARTPTO]
+
+	/* 8-bit data, no parity, Tx/Rx enabled, UART mode */
+	mov	w4, #(UARTCR_PC1 | UARTCR_RXEN | UARTCR_TXEN | UARTCR_PC0 | \
+		      UARTCR_WL0 | UARTCR_UART | UARTCR_RFBM | UARTCR_TFBM)
+	str	w4, [x0, LINFLEX_UARTCR]
+
+	/* End init mode */
+	ldr	w4, [x0, LINFLEX_LINCR1]
+	bic	w4, w4, #LINCR1_INIT
+	str	w4, [x0, LINFLEX_LINCR1]
+	ret
+endfunc console_linflex_core_init
+
+/**
+ * int console_linflex_register(uintptr_t baseaddr, uint32_t clock,
+ *                              uint32_t clock, uint32_t baud);
+ *
+ * Function to initialize and register the console.
+ * The caller needs to pass an empty console_linflex_t
+ * structure in which *MUST* be allocated in
+ * persistent memory (e.g. a global or static local
+ * variable, *NOT* on the stack).
+ * In:  x0 - Linflex base address
+ *      x1 - clock frequency
+ *      x2 - baudrate
+ *      x3 - pointer to empty console_t structure
+ * Out: x0 - 1 on success, 0 on error
+ * Clobber list : x0 - x7, x13 - x15
+ */
+func console_linflex_register
+	mov	x15, x30
+	bl	console_linflex_core_init
+	mov	x30, x15
+
+	/* Populate the base address */
+	str	x0, [x3, #CONSOLE_T_BASE]
+
+	mov	x0, x3
+	finish_console_register linflex, putc=1, getc=0, flush=0
+endfunc console_linflex_register
+
+/**
+ * int console_linflex_core_putc(int c, uintptr_t baseaddr);
+
+ * Out: w0 - printed character on success, < 0 on error.
+ * Clobber list : x0 - x3
+ */
+func console_linflex_core_putc
+	cbz	x1, putc_error
+
+	cmp	w0, #'\n'
+	b.ne	print_char
+
+	/* Print '\r\n' for each '\n' */
+	mov	x0, #'\r'
+	mov	x14, x30
+	bl	console_linflex_core_putc
+	mov	x30, x14
+	mov	x0, #'\n'
+
+print_char:
+	ldr	w2, [x1, LINFLEX_UARTCR]
+	and	w2, w2, #UARTCR_TFBM
+	cmp	w2, #0x0
+	b.eq	buffer_mode
+
+fifo_mode:
+	/* UART is in FIFO mode */
+	ldr	w2, [x1, LINFLEX_UARTSR]
+	and	w2, w2, #UARTSR_DTF
+	cmp	w2, #0
+	b.ne	fifo_mode
+
+	strb	w0, [x1, LINFLEX_BDRL]
+	b	no_error
+
+buffer_mode:
+	strb	w0, [x1, LINFLEX_BDRL]
+
+buffer_loop:
+	ldr	w2, [x1, LINFLEX_UARTSR]
+	and	w3, w2, #UARTSR_DTF
+	cmp	w3, #0
+	b.eq	buffer_loop
+
+	/**
+	 * In Buffer Mode the DTFTFF bit of UARTSR register
+	 * has to be set in software
+	 */
+	mov	w2, #UARTSR_DTF
+	str	w2, [x1, LINFLEX_UARTSR]
+
+no_error:
+	mov	x0, #0
+	ret
+
+putc_error:
+	mov	x0, #-EINVAL
+	ret
+endfunc console_linflex_core_putc
+
+/**
+ * int console_linflex_putc(int c, console_t *console);
+ *
+ * Function to output a character over the console. It
+ * returns the character printed on success or -EINVAL on error.
+ * In : w0 - character to be printed
+ *      x1 - pointer to console_t struct
+ * Out: w0 - printed character on success, < 0 on error.
+ * Clobber list : x0 - x3, x15
+ */
+func console_linflex_putc
+	cbz	x1, putc_error
+	ldr	x1, [x1, #CONSOLE_T_BASE]
+
+	b	console_linflex_core_putc
+puct_error:
+	mov	x0, #-EINVAL
+	ret
+endfunc console_linflex_putc