diff options
| -rw-r--r-- | drivers/spi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/spi/davinci_spi.c | 223 | ||||
| -rw-r--r-- | drivers/spi/davinci_spi.h | 101 | 
3 files changed, 325 insertions, 0 deletions
| diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 824d8e740..f112ed00d 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -29,6 +29,7 @@ COBJS-$(CONFIG_ATMEL_DATAFLASH_SPI) += atmel_dataflash_spi.o  COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o  COBJS-$(CONFIG_BFIN_SPI) += bfin_spi.o  COBJS-$(CONFIG_CF_SPI) += cf_spi.o +COBJS-$(CONFIG_DAVINCI_SPI) += davinci_spi.o  COBJS-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o  COBJS-$(CONFIG_MPC52XX_SPI) += mpc52xx_spi.o  COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c new file mode 100644 index 000000000..ebc7f8082 --- /dev/null +++ b/drivers/spi/davinci_spi.c @@ -0,0 +1,223 @@ +/* + * 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 + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ +#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 = malloc(sizeof(*ds)); +	if (!ds) +		return NULL; + +	ds->slave.bus = bus; +	ds->slave.cs = cs; +	ds->regs = (struct davinci_spi_regs *)CONFIG_SYS_SPI_BASE; +	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, data1_reg_val = 0; + +	/* 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((SPIPC0_EN0FUN_MASK | 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); + +	/* hold cs active at end of transfer until explicitly de-asserted */ +	data1_reg_val = (1 << SPIDAT1_CSHOLD_SHIFT) | +			(slave->cs << SPIDAT1_CSNR_SHIFT); +	writel(data1_reg_val, &ds->regs->dat1); + +	/* +	 * 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); +} + +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, +		const void *dout, void *din, unsigned long flags) +{ +	struct davinci_spi_slave *ds = to_davinci_spi(slave); +	unsigned int	len, data1_reg_val = readl(&ds->regs->dat1); +	int		ret, i; +	const u8	*txp = dout; /* dout can be NULL for read operation */ +	u8		*rxp = din;  /* din can be NULL for write operation */ + +	ret = 0; + +	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; + +	/* do an empty read to clear the current contents */ +	readl(&ds->regs->buf); + +	/* keep writing and reading 1 byte until done */ +	for (i = 0; i < len; i++) { +		/* wait till TXFULL is asserted */ +		while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK); + +		/* write the data */ +		data1_reg_val &= ~0xFFFF; +		if (txp) { +			data1_reg_val |= *txp; +			txp++; +		} + +		/* +		 * Write to DAT1 is required to keep the serial transfer going. +		 * We just terminate when we reach the end. +		 */ +		if ((i == (len - 1)) && (flags & SPI_XFER_END)) { +			/* clear CS hold */ +			writel(data1_reg_val & +				~(1 << SPIDAT1_CSHOLD_SHIFT), &ds->regs->dat1); +		} else { +			/* enable CS hold */ +			data1_reg_val |= ((1 << SPIDAT1_CSHOLD_SHIFT) | +					(slave->cs << SPIDAT1_CSNR_SHIFT)); +			writel(data1_reg_val, &ds->regs->dat1); +		} + +		/* read the data - wait for data availability */ +		while (readl(&ds->regs->buf) & SPIBUF_RXEMPTY_MASK); + +		if (rxp) { +			*rxp = readl(&ds->regs->buf) & 0xFF; +			rxp++; +		} else { +			/* simply drop the read character */ +			readl(&ds->regs->buf); +		} +	} +	return 0; + +out: +	if (flags & SPI_XFER_END) { +		writel(data1_reg_val & +			~(1 << SPIDAT1_CSHOLD_SHIFT), &ds->regs->dat1); +	} +	return 0; +} + +int spi_cs_is_valid(unsigned int bus, unsigned int cs) +{ +	return bus == 0 && cs == 0; +} + +void spi_cs_activate(struct spi_slave *slave) +{ +	/* do nothing */ +} + +void spi_cs_deactivate(struct spi_slave *slave) +{ +	/* do nothing */ +} + diff --git a/drivers/spi/davinci_spi.h b/drivers/spi/davinci_spi.h new file mode 100644 index 000000000..8d36a42a4 --- /dev/null +++ b/drivers/spi/davinci_spi.h @@ -0,0 +1,101 @@ +/* + * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/ + * + * Register definitions for the DaVinci SPI Controller + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#ifndef _DAVINCI_SPI_H_ +#define _DAVINCI_SPI_H_ + +struct davinci_spi_regs { +	dv_reg	gcr0;		/* 0x00 */ +	dv_reg	gcr1;		/* 0x04 */ +	dv_reg	int0;		/* 0x08 */ +	dv_reg	lvl;		/* 0x0c */ +	dv_reg	flg;		/* 0x10 */ +	dv_reg	pc0;		/* 0x14 */ +	dv_reg	pc1;		/* 0x18 */ +	dv_reg	pc2;		/* 0x1c */ +	dv_reg	pc3;		/* 0x20 */ +	dv_reg	pc4;		/* 0x24 */ +	dv_reg	pc5;		/* 0x28 */ +	dv_reg	rsvd[3]; +	dv_reg	dat0;		/* 0x38 */ +	dv_reg	dat1;		/* 0x3c */ +	dv_reg	buf;		/* 0x40 */ +	dv_reg	emu;		/* 0x44 */ +	dv_reg	delay;		/* 0x48 */ +	dv_reg	def;		/* 0x4c */ +	dv_reg	fmt0;		/* 0x50 */ +	dv_reg	fmt1;		/* 0x54 */ +	dv_reg	fmt2;		/* 0x58 */ +	dv_reg	fmt3;		/* 0x5c */ +	dv_reg	intvec0;	/* 0x60 */ +	dv_reg	intvec1;	/* 0x64 */ +}; + +#define BIT(x)			(1 << (x)) + +/* SPIGCR0 */ +#define SPIGCR0_SPIENA_MASK	0x1 +#define SPIGCR0_SPIRST_MASK	0x0 + +/* SPIGCR0 */ +#define SPIGCR1_CLKMOD_MASK	BIT(1) +#define SPIGCR1_MASTER_MASK	BIT(0) +#define SPIGCR1_SPIENA_MASK	BIT(24) + +/* SPIPC0 */ +#define SPIPC0_DIFUN_MASK	BIT(11)		/* SIMO */ +#define SPIPC0_DOFUN_MASK	BIT(10)		/* SOMI */ +#define SPIPC0_CLKFUN_MASK	BIT(9)		/* CLK */ +#define SPIPC0_EN0FUN_MASK	BIT(0) + +/* SPIFMT0 */ +#define SPIFMT_SHIFTDIR_SHIFT	20 +#define SPIFMT_POLARITY_SHIFT	17 +#define SPIFMT_PHASE_SHIFT	16 +#define SPIFMT_PRESCALE_SHIFT	8 + +/* SPIDAT1 */ +#define SPIDAT1_CSHOLD_SHIFT	28 +#define SPIDAT1_CSNR_SHIFT	16 + +/* SPIDELAY */ +#define SPI_C2TDELAY_SHIFT	24 +#define SPI_T2CDELAY_SHIFT	16 + +/* SPIBUF */ +#define SPIBUF_RXEMPTY_MASK	BIT(31) +#define SPIBUF_TXFULL_MASK	BIT(29) + +/* SPIDEF */ +#define SPIDEF_CSDEF0_MASK	BIT(0) + +struct davinci_spi_slave { +	struct spi_slave slave; +	struct davinci_spi_regs *regs; +	unsigned int freq; +}; + +static inline struct davinci_spi_slave *to_davinci_spi(struct spi_slave *slave) +{ +	return container_of(slave, struct davinci_spi_slave, slave); +} + +#endif /* _DAVINCI_SPI_H_ */ |