drivers/serial/serial_s5p.c - github/trini/u-boot - Gitiles

 /*
  * (C) Copyright 2009 SAMSUNG Electronics
  * Minkyu Kang <mk7.kang@samsung.com>
  * Heungjun Kim <riverful.kim@samsung.com>
  *
  * based on drivers/serial/s3c64xx.c
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */

 #include <common.h>
 #include <fdtdec.h>
 #include <linux/compiler.h>
 #include <asm/io.h>
 #include <asm/arch/uart.h>
 #include <asm/arch/clk.h>
 #include <serial.h>

 DECLARE_GLOBAL_DATA_PTR;

 #define RX_FIFO_COUNT_MASK	0xff
 #define RX_FIFO_FULL_MASK	(1 << 8)
 #define TX_FIFO_FULL_MASK	(1 << 24)

 /* Information about a serial port */
 struct fdt_serial {
 	u32 base_addr;  /* address of registers in physical memory */
 	u8 port_id;     /* uart port number */
 	u8 enabled;     /* 1 if enabled, 0 if disabled */
 } config __attribute__ ((section(".data")));

 static inline struct s5p_uart *s5p_get_base_uart(int dev_index)
 {
 #ifdef CONFIG_OF_CONTROL
 	return (struct s5p_uart *)(config.base_addr);
 #else
 	u32 offset = dev_index * sizeof(struct s5p_uart);
 	return (struct s5p_uart *)(samsung_get_base_uart() + offset);
 #endif
 }

 /*
  * The coefficient, used to calculate the baudrate on S5P UARTs is
  * calculated as
  * C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT
  * however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1,
  * 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants:
  */
 static const int udivslot[] = {
 	0,
 	0x0080,
 	0x0808,
 	0x0888,
 	0x2222,
 	0x4924,
 	0x4a52,
 	0x54aa,
 	0x5555,
 	0xd555,
 	0xd5d5,
 	0xddd5,
 	0xdddd,
 	0xdfdd,
 	0xdfdf,
 	0xffdf,
 };

 void serial_setbrg_dev(const int dev_index)
 {
 	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
 	u32 uclk = get_uart_clk(dev_index);
 	u32 baudrate = gd->baudrate;
 	u32 val;

 #if defined(CONFIG_SILENT_CONSOLE) && \
 		defined(CONFIG_OF_CONTROL) && \
 		!defined(CONFIG_SPL_BUILD)
 	if (fdtdec_get_config_int(gd->fdt_blob, "silent_console", 0))
 		gd->flags |= GD_FLG_SILENT;
 #endif

 	if (!config.enabled)
 		return;

 	val = uclk / baudrate;

 	writel(val / 16 - 1, &uart->ubrdiv);

 	if (s5p_uart_divslot())
 		writew(udivslot[val % 16], &uart->rest.slot);
 	else
 		writeb(val % 16, &uart->rest.value);
 }

 /*
  * Initialise the serial port with the given baudrate. The settings
  * are always 8 data bits, no parity, 1 stop bit, no start bits.
  */
 int serial_init_dev(const int dev_index)
 {
 	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);

 	/* enable FIFOs */
 	writel(0x1, &uart->ufcon);
 	writel(0, &uart->umcon);
 	/* 8N1 */
 	writel(0x3, &uart->ulcon);
 	/* No interrupts, no DMA, pure polling */
 	writel(0x245, &uart->ucon);

 	serial_setbrg_dev(dev_index);

 	return 0;
 }

 static int serial_err_check(const int dev_index, int op)
 {
 	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
 	unsigned int mask;

 	/*
 	 * UERSTAT
 	 * Break Detect	[3]
 	 * Frame Err	[2] : receive operation
 	 * Parity Err	[1] : receive operation
 	 * Overrun Err	[0] : receive operation
 	 */
 	if (op)
 		mask = 0x8;
 	else
 		mask = 0xf;

 	return readl(&uart->uerstat) & mask;
 }

 /*
  * Read a single byte from the serial port. Returns 1 on success, 0
  * otherwise. When the function is succesfull, the character read is
  * written into its argument c.
  */
 int serial_getc_dev(const int dev_index)
 {
 	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);

 	if (!config.enabled)
 		return 0;

 	/* wait for character to arrive */
 	while (!(readl(&uart->ufstat) & (RX_FIFO_COUNT_MASK |
 					 RX_FIFO_FULL_MASK))) {
 		if (serial_err_check(dev_index, 0))
 			return 0;
 	}

 	return (int)(readb(&uart->urxh) & 0xff);
 }

 /*
  * Output a single byte to the serial port.
  */
 void serial_putc_dev(const char c, const int dev_index)
 {
 	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);

 	if (!config.enabled)
 		return;

 	/* wait for room in the tx FIFO */
 	while ((readl(&uart->ufstat) & TX_FIFO_FULL_MASK)) {
 		if (serial_err_check(dev_index, 1))
 			return;
 	}

 	writeb(c, &uart->utxh);

 	/* If \n, also do \r */
 	if (c == '\n')
 		serial_putc('\r');
 }

 /*
  * Test whether a character is in the RX buffer
  */
 int serial_tstc_dev(const int dev_index)
 {
 	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);

 	if (!config.enabled)
 		return 0;

 	return (int)(readl(&uart->utrstat) & 0x1);
 }

 void serial_puts_dev(const char *s, const int dev_index)
 {
 	while (*s)
 		serial_putc_dev(*s++, dev_index);
 }

 /* Multi serial device functions */
 #define DECLARE_S5P_SERIAL_FUNCTIONS(port) \
 int s5p_serial##port##_init(void) { return serial_init_dev(port); } \
 void s5p_serial##port##_setbrg(void) { serial_setbrg_dev(port); } \
 int s5p_serial##port##_getc(void) { return serial_getc_dev(port); } \
 int s5p_serial##port##_tstc(void) { return serial_tstc_dev(port); } \
 void s5p_serial##port##_putc(const char c) { serial_putc_dev(c, port); } \
 void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); }

 #define INIT_S5P_SERIAL_STRUCTURE(port, __name) {	\
 	.name	= __name,				\
 	.start	= s5p_serial##port##_init,		\
 	.stop	= NULL,					\
 	.setbrg	= s5p_serial##port##_setbrg,		\
 	.getc	= s5p_serial##port##_getc,		\
 	.tstc	= s5p_serial##port##_tstc,		\
 	.putc	= s5p_serial##port##_putc,		\
 	.puts	= s5p_serial##port##_puts,		\
 }

 DECLARE_S5P_SERIAL_FUNCTIONS(0);
 struct serial_device s5p_serial0_device =
 	INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0");
 DECLARE_S5P_SERIAL_FUNCTIONS(1);
 struct serial_device s5p_serial1_device =
 	INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1");
 DECLARE_S5P_SERIAL_FUNCTIONS(2);
 struct serial_device s5p_serial2_device =
 	INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2");
 DECLARE_S5P_SERIAL_FUNCTIONS(3);
 struct serial_device s5p_serial3_device =
 	INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3");

 #ifdef CONFIG_OF_CONTROL
 int fdtdec_decode_console(int *index, struct fdt_serial *uart)
 {
 	const void *blob = gd->fdt_blob;
 	int node;

 	node = fdt_path_offset(blob, "console");
 	if (node < 0)
 		return node;

 	uart->base_addr = fdtdec_get_addr(blob, node, "reg");
 	if (uart->base_addr == FDT_ADDR_T_NONE)
 		return -FDT_ERR_NOTFOUND;

 	uart->port_id = fdtdec_get_int(blob, node, "id", -1);
 	uart->enabled = fdtdec_get_is_enabled(blob, node);

 	return 0;
 }
 #endif

 __weak struct serial_device *default_serial_console(void)
 {
 #ifdef CONFIG_OF_CONTROL
 	int index = 0;

 	if ((!config.base_addr) && (fdtdec_decode_console(&index, &config))) {
 		debug("Cannot decode default console node\n");
 		return NULL;
 	}

 	switch (config.port_id) {
 	case 0:
 		return &s5p_serial0_device;
 	case 1:
 		return &s5p_serial1_device;
 	case 2:
 		return &s5p_serial2_device;
 	case 3:
 		return &s5p_serial3_device;
 	default:
 		debug("Unknown config.port_id: %d", config.port_id);
 		break;
 	}

 	return NULL;
 #else
 	config.enabled = 1;
 #if defined(CONFIG_SERIAL0)
 	return &s5p_serial0_device;
 #elif defined(CONFIG_SERIAL1)
 	return &s5p_serial1_device;
 #elif defined(CONFIG_SERIAL2)
 	return &s5p_serial2_device;
 #elif defined(CONFIG_SERIAL3)
 	return &s5p_serial3_device;
 #else
 #error "CONFIG_SERIAL? missing."
 #endif
 #endif
 }

 void s5p_serial_initialize(void)
 {
 	serial_register(&s5p_serial0_device);
 	serial_register(&s5p_serial1_device);
 	serial_register(&s5p_serial2_device);
 	serial_register(&s5p_serial3_device);
 }
	/*
	* (C) Copyright 2009 SAMSUNG Electronics
	* Minkyu Kang <mk7.kang@samsung.com>
	* Heungjun Kim <riverful.kim@samsung.com>
	*
	* based on drivers/serial/s3c64xx.c
	*
	* SPDX-License-Identifier: GPL-2.0+
	*/

	#include <common.h>
	#include <fdtdec.h>
	#include <linux/compiler.h>
	#include <asm/io.h>
	#include <asm/arch/uart.h>
	#include <asm/arch/clk.h>
	#include <serial.h>

	DECLARE_GLOBAL_DATA_PTR;

	#define RX_FIFO_COUNT_MASK 0xff
	#define RX_FIFO_FULL_MASK (1 << 8)
	#define TX_FIFO_FULL_MASK (1 << 24)

	/* Information about a serial port */
	struct fdt_serial {
	u32 base_addr; /* address of registers in physical memory */
	u8 port_id; /* uart port number */
	u8 enabled; /* 1 if enabled, 0 if disabled */
	} config __attribute__ ((section(".data")));

	static inline struct s5p_uart *s5p_get_base_uart(int dev_index)
	{
	#ifdef CONFIG_OF_CONTROL
	return (struct s5p_uart *)(config.base_addr);
	#else
	u32 offset = dev_index * sizeof(struct s5p_uart);
	return (struct s5p_uart *)(samsung_get_base_uart() + offset);
	#endif
	}

	/*
	* The coefficient, used to calculate the baudrate on S5P UARTs is
	* calculated as
	* C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT
	* however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1,
	* 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants:
	*/
	static const int udivslot[] = {
	0,
	0x0080,
	0x0808,
	0x0888,
	0x2222,
	0x4924,
	0x4a52,
	0x54aa,
	0x5555,
	0xd555,
	0xd5d5,
	0xddd5,
	0xdddd,
	0xdfdd,
	0xdfdf,
	0xffdf,
	};

	void serial_setbrg_dev(const int dev_index)
	{
	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
	u32 uclk = get_uart_clk(dev_index);
	u32 baudrate = gd->baudrate;
	u32 val;

	#if defined(CONFIG_SILENT_CONSOLE) && \
	defined(CONFIG_OF_CONTROL) && \
	!defined(CONFIG_SPL_BUILD)
	if (fdtdec_get_config_int(gd->fdt_blob, "silent_console", 0))
	gd->flags \|= GD_FLG_SILENT;
	#endif

	if (!config.enabled)
	return;

	val = uclk / baudrate;

	writel(val / 16 - 1, &uart->ubrdiv);

	if (s5p_uart_divslot())
	writew(udivslot[val % 16], &uart->rest.slot);
	else
	writeb(val % 16, &uart->rest.value);
	}

	/*
	* Initialise the serial port with the given baudrate. The settings
	* are always 8 data bits, no parity, 1 stop bit, no start bits.
	*/
	int serial_init_dev(const int dev_index)
	{
	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);

	/* enable FIFOs */
	writel(0x1, &uart->ufcon);
	writel(0, &uart->umcon);
	/* 8N1 */
	writel(0x3, &uart->ulcon);
	/* No interrupts, no DMA, pure polling */
	writel(0x245, &uart->ucon);

	serial_setbrg_dev(dev_index);

	return 0;
	}

	static int serial_err_check(const int dev_index, int op)
	{
	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);
	unsigned int mask;

	/*
	* UERSTAT
	* Break Detect [3]
	* Frame Err [2] : receive operation
	* Parity Err [1] : receive operation
	* Overrun Err [0] : receive operation
	*/
	if (op)
	mask = 0x8;
	else
	mask = 0xf;

	return readl(&uart->uerstat) & mask;
	}

	/*
	* Read a single byte from the serial port. Returns 1 on success, 0
	* otherwise. When the function is succesfull, the character read is
	* written into its argument c.
	*/
	int serial_getc_dev(const int dev_index)
	{
	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);

	if (!config.enabled)
	return 0;

	/* wait for character to arrive */
	while (!(readl(&uart->ufstat) & (RX_FIFO_COUNT_MASK \|
	RX_FIFO_FULL_MASK))) {
	if (serial_err_check(dev_index, 0))
	return 0;
	}

	return (int)(readb(&uart->urxh) & 0xff);
	}

	/*
	* Output a single byte to the serial port.
	*/
	void serial_putc_dev(const char c, const int dev_index)
	{
	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);

	if (!config.enabled)
	return;

	/* wait for room in the tx FIFO */
	while ((readl(&uart->ufstat) & TX_FIFO_FULL_MASK)) {
	if (serial_err_check(dev_index, 1))
	return;
	}

	writeb(c, &uart->utxh);

	/* If \n, also do \r */
	if (c == '\n')
	serial_putc('\r');
	}

	/*
	* Test whether a character is in the RX buffer
	*/
	int serial_tstc_dev(const int dev_index)
	{
	struct s5p_uart *const uart = s5p_get_base_uart(dev_index);

	if (!config.enabled)
	return 0;

	return (int)(readl(&uart->utrstat) & 0x1);
	}

	void serial_puts_dev(const char *s, const int dev_index)
	{
	while (*s)
	serial_putc_dev(*s++, dev_index);
	}

	/* Multi serial device functions */
	#define DECLARE_S5P_SERIAL_FUNCTIONS(port) \
	int s5p_serial##port##_init(void) { return serial_init_dev(port); } \
	void s5p_serial##port##_setbrg(void) { serial_setbrg_dev(port); } \
	int s5p_serial##port##_getc(void) { return serial_getc_dev(port); } \
	int s5p_serial##port##_tstc(void) { return serial_tstc_dev(port); } \
	void s5p_serial##port##_putc(const char c) { serial_putc_dev(c, port); } \
	void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); }

	#define INIT_S5P_SERIAL_STRUCTURE(port, __name) { \
	.name = __name, \
	.start = s5p_serial##port##_init, \
	.stop = NULL, \
	.setbrg = s5p_serial##port##_setbrg, \
	.getc = s5p_serial##port##_getc, \
	.tstc = s5p_serial##port##_tstc, \
	.putc = s5p_serial##port##_putc, \
	.puts = s5p_serial##port##_puts, \
	}

	DECLARE_S5P_SERIAL_FUNCTIONS(0);
	struct serial_device s5p_serial0_device =
	INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0");
	DECLARE_S5P_SERIAL_FUNCTIONS(1);
	struct serial_device s5p_serial1_device =
	INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1");
	DECLARE_S5P_SERIAL_FUNCTIONS(2);
	struct serial_device s5p_serial2_device =
	INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2");
	DECLARE_S5P_SERIAL_FUNCTIONS(3);
	struct serial_device s5p_serial3_device =
	INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3");

	#ifdef CONFIG_OF_CONTROL
	int fdtdec_decode_console(int index, struct fdt_serial uart)
	{
	const void *blob = gd->fdt_blob;
	int node;

	node = fdt_path_offset(blob, "console");
	if (node < 0)
	return node;

	uart->base_addr = fdtdec_get_addr(blob, node, "reg");
	if (uart->base_addr == FDT_ADDR_T_NONE)
	return -FDT_ERR_NOTFOUND;

	uart->port_id = fdtdec_get_int(blob, node, "id", -1);
	uart->enabled = fdtdec_get_is_enabled(blob, node);

	return 0;
	}
	#endif

	__weak struct serial_device *default_serial_console(void)
	{
	#ifdef CONFIG_OF_CONTROL
	int index = 0;

	if ((!config.base_addr) && (fdtdec_decode_console(&index, &config))) {
	debug("Cannot decode default console node\n");
	return NULL;
	}

	switch (config.port_id) {
	case 0:
	return &s5p_serial0_device;
	case 1:
	return &s5p_serial1_device;
	case 2:
	return &s5p_serial2_device;
	case 3:
	return &s5p_serial3_device;
	default:
	debug("Unknown config.port_id: %d", config.port_id);
	break;
	}

	return NULL;
	#else
	config.enabled = 1;
	#if defined(CONFIG_SERIAL0)
	return &s5p_serial0_device;
	#elif defined(CONFIG_SERIAL1)
	return &s5p_serial1_device;
	#elif defined(CONFIG_SERIAL2)
	return &s5p_serial2_device;
	#elif defined(CONFIG_SERIAL3)
	return &s5p_serial3_device;
	#else
	#error "CONFIG_SERIAL? missing."
	#endif
	#endif
	}

	void s5p_serial_initialize(void)
	{
	serial_register(&s5p_serial0_device);
	serial_register(&s5p_serial1_device);
	serial_register(&s5p_serial2_device);
	serial_register(&s5p_serial3_device);
	}