[people/ms/u-boot.git] / drivers / serial / serial_stm32.c

/*
 * (C) Copyright 2015
 * Kamil Lulko, <kamil.lulko@gmail.com>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <dm.h>
#include <asm/io.h>
#include <serial.h>
#include <asm/arch/stm32.h>
#include <dm/platform_data/serial_stm32.h>

struct stm32_usart {
	u32 sr;
	u32 dr;
	u32 brr;
	u32 cr1;
	u32 cr2;
	u32 cr3;
	u32 gtpr;
};

#define USART_CR1_RE			(1 << 2)
#define USART_CR1_TE			(1 << 3)
#define USART_CR1_UE			(1 << 13)

#define USART_SR_FLAG_RXNE	(1 << 5)
#define USART_SR_FLAG_TXE		(1 << 7)

#define USART_BRR_F_MASK		0xF
#define USART_BRR_M_SHIFT	4
#define USART_BRR_M_MASK	0xFFF0

DECLARE_GLOBAL_DATA_PTR;

static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
{
	struct stm32_serial_platdata *plat = dev->platdata;
	struct stm32_usart *const usart = plat->base;
	u32  clock, int_div, frac_div, tmp;

	if (((u32)usart & STM32_BUS_MASK) == STM32_APB1PERIPH_BASE)
		clock = clock_get(CLOCK_APB1);
	else if (((u32)usart & STM32_BUS_MASK) == STM32_APB2PERIPH_BASE)
		clock = clock_get(CLOCK_APB2);
	else
		return -EINVAL;

	int_div = (25 * clock) / (4 * baudrate);
	tmp = ((int_div / 100) << USART_BRR_M_SHIFT) & USART_BRR_M_MASK;
	frac_div = int_div - (100 * (tmp >> USART_BRR_M_SHIFT));
	tmp |= (((frac_div * 16) + 50) / 100) & USART_BRR_F_MASK;
	writel(tmp, &usart->brr);

	return 0;
}

static int stm32_serial_getc(struct udevice *dev)
{
	struct stm32_serial_platdata *plat = dev->platdata;
	struct stm32_usart *const usart = plat->base;

	if ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0)
		return -EAGAIN;

	return readl(&usart->dr);
}

static int stm32_serial_putc(struct udevice *dev, const char c)
{
	struct stm32_serial_platdata *plat = dev->platdata;
	struct stm32_usart *const usart = plat->base;

	if ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0)
		return -EAGAIN;

	writel(c, &usart->dr);

	return 0;
}

static int stm32_serial_pending(struct udevice *dev, bool input)
{
	struct stm32_serial_platdata *plat = dev->platdata;
	struct stm32_usart *const usart = plat->base;

	if (input)
		return readl(&usart->sr) & USART_SR_FLAG_RXNE ? 1 : 0;
	else
		return readl(&usart->sr) & USART_SR_FLAG_TXE ? 0 : 1;
}

static int stm32_serial_probe(struct udevice *dev)
{
	struct stm32_serial_platdata *plat = dev->platdata;
	struct stm32_usart *const usart = plat->base;
	setbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);

	return 0;
}

static const struct dm_serial_ops stm32_serial_ops = {
	.putc = stm32_serial_putc,
	.pending = stm32_serial_pending,
	.getc = stm32_serial_getc,
	.setbrg = stm32_serial_setbrg,
};

U_BOOT_DRIVER(serial_stm32) = {
	.name = "serial_stm32",
	.id = UCLASS_SERIAL,
	.ops = &stm32_serial_ops,
	.probe = stm32_serial_probe,
	.flags = DM_FLAG_PRE_RELOC,
};
Commit	Line	Data
ab3f0c7d	1	/*
ab3f0c7d	2	* (C) Copyright 2015
66562414	3	* Kamil Lulko, <kamil.lulko@gmail.com>
ab3f0c7d	4	*
	5	* SPDX-License-Identifier: GPL-2.0+
	6	*/
	7
	8	#include <common.h>
66562414	9	#include <dm.h>
ab3f0c7d	10	#include <asm/io.h>
	11	#include <serial.h>
	12	#include <asm/arch/stm32.h>
66562414	13	#include <dm/platform_data/serial_stm32.h>
ab3f0c7d	14
66562414	15	struct stm32_usart {
ab3f0c7d	16	u32 sr;
	17	u32 dr;
	18	u32 brr;
	19	u32 cr1;
	20	u32 cr2;
	21	u32 cr3;
	22	u32 gtpr;
	23	};
	24
66562414 KL	25	#define USART_CR1_RE (1 << 2)
	26	#define USART_CR1_TE (1 << 3)
	27	#define USART_CR1_UE (1 << 13)
ab3f0c7d	28
ab3f0c7d	29	#define USART_SR_FLAG_RXNE (1 << 5)
66562414	30	#define USART_SR_FLAG_TXE (1 << 7)
ab3f0c7d	31
66562414	32	#define USART_BRR_F_MASK 0xF
ab3f0c7d	33	#define USART_BRR_M_SHIFT 4
	34	#define USART_BRR_M_MASK 0xFFF0
	35
	36	DECLARE_GLOBAL_DATA_PTR;
	37
66562414	38	static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
ab3f0c7d	39	{
66562414 KL	40	struct stm32_serial_platdata *plat = dev->platdata;
	41	struct stm32_usart *const usart = plat->base;
	42	u32 clock, int_div, frac_div, tmp;
ab3f0c7d	43
66562414	44	if (((u32)usart & STM32_BUS_MASK) == STM32_APB1PERIPH_BASE)
ab3f0c7d	45	clock = clock_get(CLOCK_APB1);
66562414	46	else if (((u32)usart & STM32_BUS_MASK) == STM32_APB2PERIPH_BASE)
ab3f0c7d	47	clock = clock_get(CLOCK_APB2);
66562414 KL	48	else
66562414 KL	49	return -EINVAL;
ab3f0c7d	50
66562414	51	int_div = (25 * clock) / (4 * baudrate);
ab3f0c7d	52	tmp = ((int_div / 100) << USART_BRR_M_SHIFT) & USART_BRR_M_MASK;
	53	frac_div = int_div - (100 * (tmp >> USART_BRR_M_SHIFT));
	54	tmp \|= (((frac_div * 16) + 50) / 100) & USART_BRR_F_MASK;
ab3f0c7d	55	writel(tmp, &usart->brr);
ab3f0c7d	56
	57	return 0;
	58	}
	59
66562414	60	static int stm32_serial_getc(struct udevice *dev)
ab3f0c7d	61	{
66562414 KL	62	struct stm32_serial_platdata *plat = dev->platdata;
	63	struct stm32_usart *const usart = plat->base;
	64
	65	if ((readl(&usart->sr) & USART_SR_FLAG_RXNE) == 0)
	66	return -EAGAIN;
	67
ab3f0c7d	68	return readl(&usart->dr);
	69	}
	70
66562414	71	static int stm32_serial_putc(struct udevice *dev, const char c)
ab3f0c7d	72	{
66562414 KL	73	struct stm32_serial_platdata *plat = dev->platdata;
66562414 KL	74	struct stm32_usart *const usart = plat->base;
85e5f5b7	75
66562414 KL	76	if ((readl(&usart->sr) & USART_SR_FLAG_TXE) == 0)
66562414 KL	77	return -EAGAIN;
445614cc	78
ab3f0c7d	79	writel(c, &usart->dr);
66562414 KL	80
66562414 KL	81	return 0;
ab3f0c7d	82	}
ab3f0c7d	83
66562414	84	static int stm32_serial_pending(struct udevice *dev, bool input)
ab3f0c7d	85	{
66562414 KL	86	struct stm32_serial_platdata *plat = dev->platdata;
66562414 KL	87	struct stm32_usart *const usart = plat->base;
ab3f0c7d	88
66562414 KL	89	if (input)
	90	return readl(&usart->sr) & USART_SR_FLAG_RXNE ? 1 : 0;
	91	else
	92	return readl(&usart->sr) & USART_SR_FLAG_TXE ? 0 : 1;
ab3f0c7d	93	}
ab3f0c7d	94
66562414	95	static int stm32_serial_probe(struct udevice *dev)
ab3f0c7d	96	{
66562414 KL	97	struct stm32_serial_platdata *plat = dev->platdata;
66562414 KL	98	struct stm32_usart *const usart = plat->base;
66562414 KL	99	setbits_le32(&usart->cr1, USART_CR1_RE \| USART_CR1_TE \| USART_CR1_UE);
	100
	101	return 0;
ab3f0c7d	102	}
66562414 KL	103
	104	static const struct dm_serial_ops stm32_serial_ops = {
	105	.putc = stm32_serial_putc,
	106	.pending = stm32_serial_pending,
	107	.getc = stm32_serial_getc,
	108	.setbrg = stm32_serial_setbrg,
	109	};
	110
	111	U_BOOT_DRIVER(serial_stm32) = {
	112	.name = "serial_stm32",
	113	.id = UCLASS_SERIAL,
	114	.ops = &stm32_serial_ops,
	115	.probe = stm32_serial_probe,
	116	.flags = DM_FLAG_PRE_RELOC,
	117	};