[J-u-boot.git] / drivers / spi / davinci_spi.c

/*
 * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
 *
 * Driver for SPI controller on DaVinci. Based on atmel_spi.c
 * by Atmel Corporation
 *
 * Copyright (C) 2007 Atmel Corporation
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */
#include <common.h>
#include <spi.h>
#include <malloc.h>
#include <asm/io.h>
#include <asm/arch/hardware.h>
#include "davinci_spi.h"

void spi_init()
{
	/* do nothing */
}

struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
			unsigned int max_hz, unsigned int mode)
{
	struct davinci_spi_slave	*ds;

	if (!spi_cs_is_valid(bus, cs))
		return NULL;

	ds = spi_alloc_slave(struct davinci_spi_slave, bus, cs);
	if (!ds)
		return NULL;

	ds->slave.bus = bus;
	ds->slave.cs = cs;

	switch (bus) {
	case SPI0_BUS:
		ds->regs = (struct davinci_spi_regs *)SPI0_BASE;
		break;
#ifdef CONFIG_SYS_SPI1
	case SPI1_BUS:
		ds->regs = (struct davinci_spi_regs *)SPI1_BASE;
		break;
#endif
#ifdef CONFIG_SYS_SPI2
	case SPI2_BUS:
		ds->regs = (struct davinci_spi_regs *)SPI2_BASE;
		break;
#endif
	default: /* Invalid bus number */
		return NULL;
	}

	ds->freq = max_hz;

	return &ds->slave;
}

void spi_free_slave(struct spi_slave *slave)
{
	struct davinci_spi_slave *ds = to_davinci_spi(slave);

	free(ds);
}

int spi_claim_bus(struct spi_slave *slave)
{
	struct davinci_spi_slave *ds = to_davinci_spi(slave);
	unsigned int scalar;

	/* Enable the SPI hardware */
	writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
	udelay(1000);
	writel(SPIGCR0_SPIENA_MASK, &ds->regs->gcr0);

	/* Set master mode, powered up and not activated */
	writel(SPIGCR1_MASTER_MASK | SPIGCR1_CLKMOD_MASK, &ds->regs->gcr1);

	/* CS, CLK, SIMO and SOMI are functional pins */
	writel(((1 << slave->cs) | SPIPC0_CLKFUN_MASK |
		SPIPC0_DOFUN_MASK | SPIPC0_DIFUN_MASK), &ds->regs->pc0);

	/* setup format */
	scalar = ((CONFIG_SYS_SPI_CLK / ds->freq) - 1) & 0xFF;

	/*
	 * Use following format:
	 *   character length = 8,
	 *   clock signal delayed by half clk cycle,
	 *   clock low in idle state - Mode 0,
	 *   MSB shifted out first
	 */
	writel(8 | (scalar << SPIFMT_PRESCALE_SHIFT) |
		(1 << SPIFMT_PHASE_SHIFT), &ds->regs->fmt0);

	/*
	 * Including a minor delay. No science here. Should be good even with
	 * no delay
	 */
	writel((50 << SPI_C2TDELAY_SHIFT) |
		(50 << SPI_T2CDELAY_SHIFT), &ds->regs->delay);

	/* default chip select register */
	writel(SPIDEF_CSDEF0_MASK, &ds->regs->def);

	/* no interrupts */
	writel(0, &ds->regs->int0);
	writel(0, &ds->regs->lvl);

	/* enable SPI */
	writel((readl(&ds->regs->gcr1) | SPIGCR1_SPIENA_MASK), &ds->regs->gcr1);

	return 0;
}

void spi_release_bus(struct spi_slave *slave)
{
	struct davinci_spi_slave *ds = to_davinci_spi(slave);

	/* Disable the SPI hardware */
	writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
}

/*
 * This functions needs to act like a macro to avoid pipeline reloads in the
 * loops below. Use always_inline. This gains us about 160KiB/s and the bloat
 * appears to be zero bytes (da830).
 */
__attribute__((always_inline))
static inline u32 davinci_spi_xfer_data(struct davinci_spi_slave *ds, u32 data)
{
	u32	buf_reg_val;

	/* send out data */
	writel(data, &ds->regs->dat1);

	/* wait for the data to clock in/out */
	while ((buf_reg_val = readl(&ds->regs->buf)) & SPIBUF_RXEMPTY_MASK)
		;

	return buf_reg_val;
}

static int davinci_spi_read(struct spi_slave *slave, unsigned int len,
			    u8 *rxp, unsigned long flags)
{
	struct davinci_spi_slave *ds = to_davinci_spi(slave);
	unsigned int data1_reg_val;

	/* enable CS hold, CS[n] and clear the data bits */
	data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
			 (slave->cs << SPIDAT1_CSNR_SHIFT));

	/* wait till TXFULL is deasserted */
	while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
		;

	/* preload the TX buffer to avoid clock starvation */
	writel(data1_reg_val, &ds->regs->dat1);

	/* keep reading 1 byte until only 1 byte left */
	while ((len--) > 1)
		*rxp++ = davinci_spi_xfer_data(ds, data1_reg_val);

	/* clear CS hold when we reach the end */
	if (flags & SPI_XFER_END)
		data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);

	/* read the last byte */
	*rxp = davinci_spi_xfer_data(ds, data1_reg_val);

	return 0;
}

static int davinci_spi_write(struct spi_slave *slave, unsigned int len,
			     const u8 *txp, unsigned long flags)
{
	struct davinci_spi_slave *ds = to_davinci_spi(slave);
	unsigned int data1_reg_val;

	/* enable CS hold and clear the data bits */
	data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
			 (slave->cs << SPIDAT1_CSNR_SHIFT));

	/* wait till TXFULL is deasserted */
	while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
		;

	/* preload the TX buffer to avoid clock starvation */
	if (len > 2) {
		writel(data1_reg_val | *txp++, &ds->regs->dat1);
		len--;
	}

	/* keep writing 1 byte until only 1 byte left */
	while ((len--) > 1)
		davinci_spi_xfer_data(ds, data1_reg_val | *txp++);

	/* clear CS hold when we reach the end */
	if (flags & SPI_XFER_END)
		data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);

	/* write the last byte */
	davinci_spi_xfer_data(ds, data1_reg_val | *txp);

	return 0;
}

#ifndef CONFIG_SPI_HALF_DUPLEX
static int davinci_spi_read_write(struct spi_slave *slave, unsigned int len,
				  u8 *rxp, const u8 *txp, unsigned long flags)
{
	struct davinci_spi_slave *ds = to_davinci_spi(slave);
	unsigned int data1_reg_val;

	/* enable CS hold and clear the data bits */
	data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
			 (slave->cs << SPIDAT1_CSNR_SHIFT));

	/* wait till TXFULL is deasserted */
	while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
		;

	/* keep reading and writing 1 byte until only 1 byte left */
	while ((len--) > 1)
		*rxp++ = davinci_spi_xfer_data(ds, data1_reg_val | *txp++);

	/* clear CS hold when we reach the end */
	if (flags & SPI_XFER_END)
		data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);

	/* read and write the last byte */
	*rxp = davinci_spi_xfer_data(ds, data1_reg_val | *txp);

	return 0;
}
#endif

int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
	     const void *dout, void *din, unsigned long flags)
{
	unsigned int len;

	if (bitlen == 0)
		/* Finish any previously submitted transfers */
		goto out;

	/*
	 * It's not clear how non-8-bit-aligned transfers are supposed to be
	 * represented as a stream of bytes...this is a limitation of
	 * the current SPI interface - here we terminate on receiving such a
	 * transfer request.
	 */
	if (bitlen % 8) {
		/* Errors always terminate an ongoing transfer */
		flags |= SPI_XFER_END;
		goto out;
	}

	len = bitlen / 8;

	if (!dout)
		return davinci_spi_read(slave, len, din, flags);
	else if (!din)
		return davinci_spi_write(slave, len, dout, flags);
#ifndef CONFIG_SPI_HALF_DUPLEX
	else
		return davinci_spi_read_write(slave, len, din, dout, flags);
#else
	printf("SPI full duplex transaction requested with "
	       "CONFIG_SPI_HALF_DUPLEX defined.\n");
	flags |= SPI_XFER_END;
#endif

out:
	if (flags & SPI_XFER_END) {
		u8 dummy = 0;
		davinci_spi_write(slave, 1, &dummy, flags);
	}
	return 0;
}

int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
	int ret = 0;

	switch (bus) {
	case SPI0_BUS:
		if (cs < SPI0_NUM_CS)
			ret = 1;
		break;
#ifdef CONFIG_SYS_SPI1
	case SPI1_BUS:
		if (cs < SPI1_NUM_CS)
			ret = 1;
		break;
#endif
#ifdef CONFIG_SYS_SPI2
	case SPI2_BUS:
		if (cs < SPI2_NUM_CS)
			ret = 1;
		break;
#endif
	default:
		/* Invalid bus number. Do nothing */
		break;
	}
	return ret;
}

void spi_cs_activate(struct spi_slave *slave)
{
	/* do nothing */
}

void spi_cs_deactivate(struct spi_slave *slave)
{
	/* do nothing */
}
Commit	Line	Data
8ed58856 SN	1	/*
	2	* Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
	3	*
	4	* Driver for SPI controller on DaVinci. Based on atmel_spi.c
	5	* by Atmel Corporation
	6	*
	7	* Copyright (C) 2007 Atmel Corporation
	8	*
1a459660	9	* SPDX-License-Identifier: GPL-2.0+
8ed58856 SN	10	*/
	11	#include <common.h>
	12	#include <spi.h>
	13	#include <malloc.h>
	14	#include <asm/io.h>
	15	#include <asm/arch/hardware.h>
	16	#include "davinci_spi.h"
	17
	18	void spi_init()
	19	{
	20	/* do nothing */
	21	}
	22
	23	struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
	24	unsigned int max_hz, unsigned int mode)
	25	{
	26	struct davinci_spi_slave *ds;
	27
	28	if (!spi_cs_is_valid(bus, cs))
	29	return NULL;
	30
d3504fee	31	ds = spi_alloc_slave(struct davinci_spi_slave, bus, cs);
8ed58856 SN	32	if (!ds)
	33	return NULL;
	34
2bcdf84d KM	35	ds->slave.bus = bus;
	36	ds->slave.cs = cs;
	37
	38	switch (bus) {
	39	case SPI0_BUS:
	40	ds->regs = (struct davinci_spi_regs *)SPI0_BASE;
	41	break;
	42	#ifdef CONFIG_SYS_SPI1
	43	case SPI1_BUS:
7a4861fa	44	ds->regs = (struct davinci_spi_regs *)SPI1_BASE;
2bcdf84d KM	45	break;
	46	#endif
	47	#ifdef CONFIG_SYS_SPI2
	48	case SPI2_BUS:
	49	ds->regs = (struct davinci_spi_regs *)SPI2_BASE;
	50	break;
	51	#endif
	52	default: /* Invalid bus number */
	53	return NULL;
	54	}
	55
8ed58856 SN	56	ds->freq = max_hz;
	57
	58	return &ds->slave;
	59	}
	60
	61	void spi_free_slave(struct spi_slave *slave)
	62	{
	63	struct davinci_spi_slave *ds = to_davinci_spi(slave);
	64
	65	free(ds);
	66	}
	67
	68	int spi_claim_bus(struct spi_slave *slave)
	69	{
	70	struct davinci_spi_slave *ds = to_davinci_spi(slave);
77436d66	71	unsigned int scalar;
8ed58856 SN	72
	73	/* Enable the SPI hardware */
	74	writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
	75	udelay(1000);
	76	writel(SPIGCR0_SPIENA_MASK, &ds->regs->gcr0);
	77
	78	/* Set master mode, powered up and not activated */
	79	writel(SPIGCR1_MASTER_MASK \| SPIGCR1_CLKMOD_MASK, &ds->regs->gcr1);
	80
	81	/* CS, CLK, SIMO and SOMI are functional pins */
2bcdf84d	82	writel(((1 << slave->cs) \| SPIPC0_CLKFUN_MASK \|
8ed58856 SN	83	SPIPC0_DOFUN_MASK \| SPIPC0_DIFUN_MASK), &ds->regs->pc0);
	84
	85	/* setup format */
	86	scalar = ((CONFIG_SYS_SPI_CLK / ds->freq) - 1) & 0xFF;
	87
	88	/*
	89	* Use following format:
	90	* character length = 8,
	91	* clock signal delayed by half clk cycle,
	92	* clock low in idle state - Mode 0,
	93	* MSB shifted out first
	94	*/
	95	writel(8 \| (scalar << SPIFMT_PRESCALE_SHIFT) \|
	96	(1 << SPIFMT_PHASE_SHIFT), &ds->regs->fmt0);
	97
8ed58856 SN	98	/*
	99	* Including a minor delay. No science here. Should be good even with
	100	* no delay
	101	*/
	102	writel((50 << SPI_C2TDELAY_SHIFT) \|
	103	(50 << SPI_T2CDELAY_SHIFT), &ds->regs->delay);
	104
	105	/* default chip select register */
	106	writel(SPIDEF_CSDEF0_MASK, &ds->regs->def);
	107
	108	/* no interrupts */
	109	writel(0, &ds->regs->int0);
	110	writel(0, &ds->regs->lvl);
	111
	112	/* enable SPI */
77436d66	113	writel((readl(&ds->regs->gcr1) \| SPIGCR1_SPIENA_MASK), &ds->regs->gcr1);
8ed58856 SN	114
	115	return 0;
	116	}
	117
	118	void spi_release_bus(struct spi_slave *slave)
	119	{
	120	struct davinci_spi_slave *ds = to_davinci_spi(slave);
	121
	122	/* Disable the SPI hardware */
	123	writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
	124	}
	125
77436d66 NT	126	/*
	127	* This functions needs to act like a macro to avoid pipeline reloads in the
	128	* loops below. Use always_inline. This gains us about 160KiB/s and the bloat
	129	* appears to be zero bytes (da830).
	130	*/
	131	__attribute__((always_inline))
	132	static inline u32 davinci_spi_xfer_data(struct davinci_spi_slave *ds, u32 data)
	133	{
	134	u32 buf_reg_val;
	135
	136	/* send out data */
	137	writel(data, &ds->regs->dat1);
	138
	139	/* wait for the data to clock in/out */
	140	while ((buf_reg_val = readl(&ds->regs->buf)) & SPIBUF_RXEMPTY_MASK)
	141	;
	142
	143	return buf_reg_val;
	144	}
	145
	146	static int davinci_spi_read(struct spi_slave *slave, unsigned int len,
	147	u8 *rxp, unsigned long flags)
	148	{
	149	struct davinci_spi_slave *ds = to_davinci_spi(slave);
	150	unsigned int data1_reg_val;
	151
	152	/* enable CS hold, CS[n] and clear the data bits */
	153	data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) \|
	154	(slave->cs << SPIDAT1_CSNR_SHIFT));
	155
	156	/* wait till TXFULL is deasserted */
	157	while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
	158	;
	159
	160	/* preload the TX buffer to avoid clock starvation */
	161	writel(data1_reg_val, &ds->regs->dat1);
	162
	163	/* keep reading 1 byte until only 1 byte left */
	164	while ((len--) > 1)
	165	*rxp++ = davinci_spi_xfer_data(ds, data1_reg_val);
	166
	167	/* clear CS hold when we reach the end */
	168	if (flags & SPI_XFER_END)
	169	data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
	170
	171	/* read the last byte */
	172	*rxp = davinci_spi_xfer_data(ds, data1_reg_val);
	173
	174	return 0;
	175	}
	176
	177	static int davinci_spi_write(struct spi_slave *slave, unsigned int len,
dce6538f	178	const u8 *txp, unsigned long flags)
77436d66 NT	179	{
	180	struct davinci_spi_slave *ds = to_davinci_spi(slave);
	181	unsigned int data1_reg_val;
	182
	183	/* enable CS hold and clear the data bits */
	184	data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) \|
	185	(slave->cs << SPIDAT1_CSNR_SHIFT));
	186
	187	/* wait till TXFULL is deasserted */
	188	while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
	189	;
	190
	191	/* preload the TX buffer to avoid clock starvation */
	192	if (len > 2) {
	193	writel(data1_reg_val \| *txp++, &ds->regs->dat1);
	194	len--;
	195	}
	196
	197	/* keep writing 1 byte until only 1 byte left */
	198	while ((len--) > 1)
	199	davinci_spi_xfer_data(ds, data1_reg_val \| *txp++);
	200
	201	/* clear CS hold when we reach the end */
	202	if (flags & SPI_XFER_END)
	203	data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
	204
	205	/* write the last byte */
	206	davinci_spi_xfer_data(ds, data1_reg_val \| *txp);
	207
	208	return 0;
	209	}
	210
	211	#ifndef CONFIG_SPI_HALF_DUPLEX
	212	static int davinci_spi_read_write(struct spi_slave *slave, unsigned int len,
	213	u8 rxp, const u8 txp, unsigned long flags)
	214	{
	215	struct davinci_spi_slave *ds = to_davinci_spi(slave);
	216	unsigned int data1_reg_val;
	217
	218	/* enable CS hold and clear the data bits */
	219	data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) \|
	220	(slave->cs << SPIDAT1_CSNR_SHIFT));
	221
	222	/* wait till TXFULL is deasserted */
	223	while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
	224	;
	225
	226	/* keep reading and writing 1 byte until only 1 byte left */
	227	while ((len--) > 1)
	228	rxp++ = davinci_spi_xfer_data(ds, data1_reg_val \| txp++);
	229
	230	/* clear CS hold when we reach the end */
	231	if (flags & SPI_XFER_END)
	232	data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
	233
	234	/* read and write the last byte */
	235	rxp = davinci_spi_xfer_data(ds, data1_reg_val \| txp);
	236
	237	return 0;
	238	}
	239	#endif
	240
8ed58856	241	int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
dce6538f	242	const void dout, void din, unsigned long flags)
8ed58856	243	{
77436d66	244	unsigned int len;
8ed58856	245
8ed58856 SN	246	if (bitlen == 0)
	247	/* Finish any previously submitted transfers */
	248	goto out;
	249
	250	/*
	251	* It's not clear how non-8-bit-aligned transfers are supposed to be
	252	* represented as a stream of bytes...this is a limitation of
	253	* the current SPI interface - here we terminate on receiving such a
	254	* transfer request.
	255	*/
	256	if (bitlen % 8) {
	257	/* Errors always terminate an ongoing transfer */
	258	flags \|= SPI_XFER_END;
	259	goto out;
	260	}
	261
	262	len = bitlen / 8;
	263
77436d66 NT	264	if (!dout)
	265	return davinci_spi_read(slave, len, din, flags);
	266	else if (!din)
	267	return davinci_spi_write(slave, len, dout, flags);
	268	#ifndef CONFIG_SPI_HALF_DUPLEX
	269	else
	270	return davinci_spi_read_write(slave, len, din, dout, flags);
dce6538f NT	271	#else
	272	printf("SPI full duplex transaction requested with "
	273	"CONFIG_SPI_HALF_DUPLEX defined.\n");
	274	flags \|= SPI_XFER_END;
77436d66	275	#endif
8ed58856 SN	276
	277	out:
	278	if (flags & SPI_XFER_END) {
77436d66 NT	279	u8 dummy = 0;
77436d66 NT	280	davinci_spi_write(slave, 1, &dummy, flags);
8ed58856 SN	281	}
	282	return 0;
	283	}
	284
	285	int spi_cs_is_valid(unsigned int bus, unsigned int cs)
	286	{
2bcdf84d KM	287	int ret = 0;
	288
	289	switch (bus) {
	290	case SPI0_BUS:
	291	if (cs < SPI0_NUM_CS)
	292	ret = 1;
	293	break;
	294	#ifdef CONFIG_SYS_SPI1
	295	case SPI1_BUS:
	296	if (cs < SPI1_NUM_CS)
	297	ret = 1;
	298	break;
	299	#endif
	300	#ifdef CONFIG_SYS_SPI2
	301	case SPI2_BUS:
	302	if (cs < SPI2_NUM_CS)
	303	ret = 1;
	304	break;
	305	#endif
	306	default:
	307	/* Invalid bus number. Do nothing */
	308	break;
	309	}
	310	return ret;
8ed58856 SN	311	}
	312
	313	void spi_cs_activate(struct spi_slave *slave)
	314	{
	315	/* do nothing */
	316	}
	317
	318	void spi_cs_deactivate(struct spi_slave *slave)
	319	{
	320	/* do nothing */
	321	}