diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/i2c/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/soft_i2c.c | 423 | ||||
| -rw-r--r-- | drivers/net/phy/Makefile | 46 | ||||
| -rw-r--r-- | drivers/net/phy/miiphybb.c | 235 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 3 | ||||
| -rw-r--r-- | drivers/spi/soft_spi.c | 193 |
6 files changed, 900 insertions, 1 deletions
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile index 1f25afb..6079c05 100644 --- a/drivers/i2c/Makefile +++ b/drivers/i2c/Makefile @@ -29,6 +29,7 @@ COBJS-$(CONFIG_FSL_I2C) += fsl_i2c.o COBJS-$(CONFIG_I2C_MXC) += mxc_i2c.o COBJS-$(CONFIG_DRIVER_OMAP1510_I2C) += omap1510_i2c.o COBJS-$(CONFIG_DRIVER_OMAP24XX_I2C) += omap24xx_i2c.o +COBJS-$(CONFIG_SOFT_I2C) += soft_i2c.o COBJS-$(CONFIG_TSI108_I2C) += tsi108_i2c.o COBJS := $(COBJS-y) diff --git a/drivers/i2c/soft_i2c.c b/drivers/i2c/soft_i2c.c new file mode 100644 index 0000000..23db2ee --- /dev/null +++ b/drivers/i2c/soft_i2c.c @@ -0,0 +1,423 @@ +/* + * (C) Copyright 2001, 2002 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * 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 + * + * This has been changed substantially by Gerald Van Baren, Custom IDEAS, + * vanbaren@cideas.com. It was heavily influenced by LiMon, written by + * Neil Russell. + */ + +#include <common.h> +#ifdef CONFIG_MPC8260 /* only valid for MPC8260 */ +#include <ioports.h> +#endif +#ifdef CONFIG_AT91RM9200 /* need this for the at91rm9200 */ +#include <asm/io.h> +#include <asm/arch/hardware.h> +#endif +#ifdef CONFIG_IXP425 /* only valid for IXP425 */ +#include <asm/arch/ixp425.h> +#endif +#ifdef CONFIG_LPC2292 +#include <asm/arch/hardware.h> +#endif +#include <i2c.h> + +/* #define DEBUG_I2C */ + +#ifdef DEBUG_I2C +DECLARE_GLOBAL_DATA_PTR; +#endif + + +/*----------------------------------------------------------------------- + * Definitions + */ + +#define RETRIES 0 + + +#define I2C_ACK 0 /* PD_SDA level to ack a byte */ +#define I2C_NOACK 1 /* PD_SDA level to noack a byte */ + + +#ifdef DEBUG_I2C +#define PRINTD(fmt,args...) do { \ + if (gd->have_console) \ + printf (fmt ,##args); \ + } while (0) +#else +#define PRINTD(fmt,args...) +#endif + +/*----------------------------------------------------------------------- + * Local functions + */ +static void send_reset (void); +static void send_start (void); +static void send_stop (void); +static void send_ack (int); +static int write_byte (uchar byte); +static uchar read_byte (int); + + +/*----------------------------------------------------------------------- + * Send a reset sequence consisting of 9 clocks with the data signal high + * to clock any confused device back into an idle state. Also send a + * <stop> at the end of the sequence for belts & suspenders. + */ +static void send_reset(void) +{ +#ifdef CONFIG_MPC8260 + volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT); +#endif +#ifdef CONFIG_8xx + volatile immap_t *immr = (immap_t *)CFG_IMMR; +#endif + int j; + + I2C_SCL(1); + I2C_SDA(1); +#ifdef I2C_INIT + I2C_INIT; +#endif + I2C_TRISTATE; + for(j = 0; j < 9; j++) { + I2C_SCL(0); + I2C_DELAY; + I2C_DELAY; + I2C_SCL(1); + I2C_DELAY; + I2C_DELAY; + } + send_stop(); + I2C_TRISTATE; +} + +/*----------------------------------------------------------------------- + * START: High -> Low on SDA while SCL is High + */ +static void send_start(void) +{ +#ifdef CONFIG_MPC8260 + volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT); +#endif +#ifdef CONFIG_8xx + volatile immap_t *immr = (immap_t *)CFG_IMMR; +#endif + + I2C_DELAY; + I2C_SDA(1); + I2C_ACTIVE; + I2C_DELAY; + I2C_SCL(1); + I2C_DELAY; + I2C_SDA(0); + I2C_DELAY; +} + +/*----------------------------------------------------------------------- + * STOP: Low -> High on SDA while SCL is High + */ +static void send_stop(void) +{ +#ifdef CONFIG_MPC8260 + volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT); +#endif +#ifdef CONFIG_8xx + volatile immap_t *immr = (immap_t *)CFG_IMMR; +#endif + + I2C_SCL(0); + I2C_DELAY; + I2C_SDA(0); + I2C_ACTIVE; + I2C_DELAY; + I2C_SCL(1); + I2C_DELAY; + I2C_SDA(1); + I2C_DELAY; + I2C_TRISTATE; +} + + +/*----------------------------------------------------------------------- + * ack should be I2C_ACK or I2C_NOACK + */ +static void send_ack(int ack) +{ +#ifdef CONFIG_MPC8260 + volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT); +#endif +#ifdef CONFIG_8xx + volatile immap_t *immr = (immap_t *)CFG_IMMR; +#endif + + I2C_SCL(0); + I2C_DELAY; + I2C_ACTIVE; + I2C_SDA(ack); + I2C_DELAY; + I2C_SCL(1); + I2C_DELAY; + I2C_DELAY; + I2C_SCL(0); + I2C_DELAY; +} + + +/*----------------------------------------------------------------------- + * Send 8 bits and look for an acknowledgement. + */ +static int write_byte(uchar data) +{ +#ifdef CONFIG_MPC8260 + volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT); +#endif +#ifdef CONFIG_8xx + volatile immap_t *immr = (immap_t *)CFG_IMMR; +#endif + int j; + int nack; + + I2C_ACTIVE; + for(j = 0; j < 8; j++) { + I2C_SCL(0); + I2C_DELAY; + I2C_SDA(data & 0x80); + I2C_DELAY; + I2C_SCL(1); + I2C_DELAY; + I2C_DELAY; + + data <<= 1; + } + + /* + * Look for an <ACK>(negative logic) and return it. + */ + I2C_SCL(0); + I2C_DELAY; + I2C_SDA(1); + I2C_TRISTATE; + I2C_DELAY; + I2C_SCL(1); + I2C_DELAY; + I2C_DELAY; + nack = I2C_READ; + I2C_SCL(0); + I2C_DELAY; + I2C_ACTIVE; + + return(nack); /* not a nack is an ack */ +} + + +/*----------------------------------------------------------------------- + * if ack == I2C_ACK, ACK the byte so can continue reading, else + * send I2C_NOACK to end the read. + */ +static uchar read_byte(int ack) +{ +#ifdef CONFIG_MPC8260 + volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT); +#endif +#ifdef CONFIG_8xx + volatile immap_t *immr = (immap_t *)CFG_IMMR; +#endif + int data; + int j; + + /* + * Read 8 bits, MSB first. + */ + I2C_TRISTATE; + I2C_SDA(1); + data = 0; + for(j = 0; j < 8; j++) { + I2C_SCL(0); + I2C_DELAY; + I2C_SCL(1); + I2C_DELAY; + data <<= 1; + data |= I2C_READ; + I2C_DELAY; + } + send_ack(ack); + + return(data); +} + +/*=====================================================================*/ +/* Public Functions */ +/*=====================================================================*/ + +/*----------------------------------------------------------------------- + * Initialization + */ +void i2c_init (int speed, int slaveaddr) +{ + /* + * WARNING: Do NOT save speed in a static variable: if the + * I2C routines are called before RAM is initialized (to read + * the DIMM SPD, for instance), RAM won't be usable and your + * system will crash. + */ + send_reset (); +} + +/*----------------------------------------------------------------------- + * Probe to see if a chip is present. Also good for checking for the + * completion of EEPROM writes since the chip stops responding until + * the write completes (typically 10mSec). + */ +int i2c_probe(uchar addr) +{ + int rc; + + /* + * perform 1 byte write transaction with just address byte + * (fake write) + */ + send_start(); + rc = write_byte ((addr << 1) | 0); + send_stop(); + + return (rc ? 1 : 0); +} + +/*----------------------------------------------------------------------- + * Read bytes + */ +int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) +{ + int shift; + PRINTD("i2c_read: chip %02X addr %02X alen %d buffer %p len %d\n", + chip, addr, alen, buffer, len); + +#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW + /* + * EEPROM chips that implement "address overflow" are ones + * like Catalyst 24WC04/08/16 which has 9/10/11 bits of + * address and the extra bits end up in the "chip address" + * bit slots. This makes a 24WC08 (1Kbyte) chip look like + * four 256 byte chips. + * + * Note that we consider the length of the address field to + * still be one byte because the extra address bits are + * hidden in the chip address. + */ + chip |= ((addr >> (alen * 8)) & CFG_I2C_EEPROM_ADDR_OVERFLOW); + + PRINTD("i2c_read: fix addr_overflow: chip %02X addr %02X\n", + chip, addr); +#endif + + /* + * Do the addressing portion of a write cycle to set the + * chip's address pointer. If the address length is zero, + * don't do the normal write cycle to set the address pointer, + * there is no address pointer in this chip. + */ + send_start(); + if(alen > 0) { + if(write_byte(chip << 1)) { /* write cycle */ + send_stop(); + PRINTD("i2c_read, no chip responded %02X\n", chip); + return(1); + } + shift = (alen-1) * 8; + while(alen-- > 0) { + if(write_byte(addr >> shift)) { + PRINTD("i2c_read, address not <ACK>ed\n"); + return(1); + } + shift -= 8; + } + send_stop(); /* reportedly some chips need a full stop */ + send_start(); + } + /* + * Send the chip address again, this time for a read cycle. + * Then read the data. On the last byte, we do a NACK instead + * of an ACK(len == 0) to terminate the read. + */ + write_byte((chip << 1) | 1); /* read cycle */ + while(len-- > 0) { + *buffer++ = read_byte(len == 0); + } + send_stop(); + return(0); +} + +/*----------------------------------------------------------------------- + * Write bytes + */ +int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) +{ + int shift, failures = 0; + + PRINTD("i2c_write: chip %02X addr %02X alen %d buffer %p len %d\n", + chip, addr, alen, buffer, len); + + send_start(); + if(write_byte(chip << 1)) { /* write cycle */ + send_stop(); + PRINTD("i2c_write, no chip responded %02X\n", chip); + return(1); + } + shift = (alen-1) * 8; + while(alen-- > 0) { + if(write_byte(addr >> shift)) { + PRINTD("i2c_write, address not <ACK>ed\n"); + return(1); + } + shift -= 8; + } + + while(len-- > 0) { + if(write_byte(*buffer++)) { + failures++; + } + } + send_stop(); + return(failures); +} + +/*----------------------------------------------------------------------- + * Read a register + */ +uchar i2c_reg_read(uchar i2c_addr, uchar reg) +{ + uchar buf; + + i2c_read(i2c_addr, reg, 1, &buf, 1); + + return(buf); +} + +/*----------------------------------------------------------------------- + * Write a register + */ +void i2c_reg_write(uchar i2c_addr, uchar reg, uchar val) +{ + i2c_write(i2c_addr, reg, 1, &val, 1); +} diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile new file mode 100644 index 0000000..4fe3b05 --- /dev/null +++ b/drivers/net/phy/Makefile @@ -0,0 +1,46 @@ +# +# (C) Copyright 2008 +# Wolfgang Denk, DENX Software Engineering, wd@denx.de. +# +# 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 $(TOPDIR)/config.mk + +LIB := $(obj)libphy.a + +COBJS-$(CONFIG_BITBANGMII) += miiphybb.o + +COBJS := $(COBJS-y) +SRCS := $(COBJS:.o=.c) +OBJS := $(addprefix $(obj),$(COBJS)) + +all: $(LIB) + +$(LIB): $(obj).depend $(OBJS) + $(AR) $(ARFLAGS) $@ $(OBJS) + +######################################################################### + +# defines $(obj).depend target +include $(SRCTREE)/rules.mk + +sinclude $(obj).depend + +######################################################################### diff --git a/drivers/net/phy/miiphybb.c b/drivers/net/phy/miiphybb.c new file mode 100644 index 0000000..6446012 --- /dev/null +++ b/drivers/net/phy/miiphybb.c @@ -0,0 +1,235 @@ +/* + * (C) Copyright 2001 + * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com. + * + * 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 + */ + +/* + * This provides a bit-banged interface to the ethernet MII management + * channel. + */ + +#include <common.h> +#include <ioports.h> +#include <ppc_asm.tmpl> + +/***************************************************************************** + * + * Utility to send the preamble, address, and register (common to read + * and write). + */ +static void miiphy_pre (char read, unsigned char addr, unsigned char reg) +{ + int j; /* counter */ +#if !(defined(CONFIG_EP8248) || defined(CONFIG_EP82XXM)) + volatile ioport_t *iop = ioport_addr ((immap_t *) CFG_IMMR, MDIO_PORT); +#endif + + /* + * Send a 32 bit preamble ('1's) with an extra '1' bit for good measure. + * The IEEE spec says this is a PHY optional requirement. The AMD + * 79C874 requires one after power up and one after a MII communications + * error. This means that we are doing more preambles than we need, + * but it is safer and will be much more robust. + */ + + MDIO_ACTIVE; + MDIO (1); + for (j = 0; j < 32; j++) { + MDC (0); + MIIDELAY; + MDC (1); + MIIDELAY; + } + + /* send the start bit (01) and the read opcode (10) or write (10) */ + MDC (0); + MDIO (0); + MIIDELAY; + MDC (1); + MIIDELAY; + MDC (0); + MDIO (1); + MIIDELAY; + MDC (1); + MIIDELAY; + MDC (0); + MDIO (read); + MIIDELAY; + MDC (1); + MIIDELAY; + MDC (0); + MDIO (!read); + MIIDELAY; + MDC (1); + MIIDELAY; + + /* send the PHY address */ + for (j = 0; j < 5; j++) { + MDC (0); + if ((addr & 0x10) == 0) { + MDIO (0); + } else { + MDIO (1); + } + MIIDELAY; + MDC (1); + MIIDELAY; + addr <<= 1; + } + + /* send the register address */ + for (j = 0; j < 5; j++) { + MDC (0); + if ((reg & 0x10) == 0) { + MDIO (0); + } else { + MDIO (1); + } + MIIDELAY; + MDC (1); + MIIDELAY; + reg <<= 1; + } +} + + +/***************************************************************************** + * + * Read a MII PHY register. + * + * Returns: + * 0 on success + */ +int bb_miiphy_read (char *devname, unsigned char addr, + unsigned char reg, unsigned short *value) +{ + short rdreg; /* register working value */ + int j; /* counter */ +#if !(defined(CONFIG_EP8248) || defined(CONFIG_EP82XXM)) + volatile ioport_t *iop = ioport_addr ((immap_t *) CFG_IMMR, MDIO_PORT); +#endif + + miiphy_pre (1, addr, reg); + + /* tri-state our MDIO I/O pin so we can read */ + MDC (0); + MDIO_TRISTATE; + MIIDELAY; + MDC (1); + MIIDELAY; + + /* check the turnaround bit: the PHY should be driving it to zero */ + if (MDIO_READ != 0) { + /* puts ("PHY didn't drive TA low\n"); */ + for (j = 0; j < 32; j++) { + MDC (0); + MIIDELAY; + MDC (1); + MIIDELAY; + } + return (-1); + } + + MDC (0); + MIIDELAY; + + /* read 16 bits of register data, MSB first */ + rdreg = 0; + for (j = 0; j < 16; j++) { + MDC (1); + MIIDELAY; + rdreg <<= 1; + rdreg |= MDIO_READ; + MDC (0); + MIIDELAY; + } + + MDC (1); + MIIDELAY; + MDC (0); + MIIDELAY; + MDC (1); + MIIDELAY; + + *value = rdreg; + +#ifdef DEBUG + printf ("miiphy_read(0x%x) @ 0x%x = 0x%04x\n", reg, addr, *value); +#endif + + return 0; +} + + +/***************************************************************************** + * + * Write a MII PHY register. + * + * Returns: + * 0 on success + */ +int bb_miiphy_write (char *devname, unsigned char addr, + unsigned char reg, unsigned short value) +{ + int j; /* counter */ +#if !(defined(CONFIG_EP8248) || defined(CONFIG_EP82XXM)) + volatile ioport_t *iop = ioport_addr ((immap_t *) CFG_IMMR, MDIO_PORT); +#endif + + miiphy_pre (0, addr, reg); + + /* send the turnaround (10) */ + MDC (0); + MDIO (1); + MIIDELAY; + MDC (1); + MIIDELAY; + MDC (0); + MDIO (0); + MIIDELAY; + MDC (1); + MIIDELAY; + + /* write 16 bits of register data, MSB first */ + for (j = 0; j < 16; j++) { + MDC (0); + if ((value & 0x00008000) == 0) { + MDIO (0); + } else { + MDIO (1); + } + MIIDELAY; + MDC (1); + MIIDELAY; + value <<= 1; + } + + /* + * Tri-state the MDIO line. + */ + MDIO_TRISTATE; + MDC (0); + MIIDELAY; + MDC (1); + MIIDELAY; + + return 0; +} diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 4f7b679..15e0f7a 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -25,9 +25,10 @@ include $(TOPDIR)/config.mk LIB := $(obj)libspi.a -COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o +COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o +COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o COBJS := $(COBJS-y) SRCS := $(COBJS:.o=.c) diff --git a/drivers/spi/soft_spi.c b/drivers/spi/soft_spi.c new file mode 100644 index 0000000..25b589a --- /dev/null +++ b/drivers/spi/soft_spi.c @@ -0,0 +1,193 @@ +/* + * (C) Copyright 2002 + * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com. + * + * Influenced by code from: + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * 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> + +/*----------------------------------------------------------------------- + * Definitions + */ + +#ifdef DEBUG_SPI +#define PRINTD(fmt,args...) printf (fmt ,##args) +#else +#define PRINTD(fmt,args...) +#endif + +struct soft_spi_slave { + struct spi_slave slave; + unsigned int mode; +}; + +static inline struct soft_spi_slave *to_soft_spi(struct spi_slave *slave) +{ + return container_of(slave, struct soft_spi_slave, slave); +} + +/*=====================================================================*/ +/* Public Functions */ +/*=====================================================================*/ + +/*----------------------------------------------------------------------- + * Initialization + */ +void spi_init (void) +{ +#ifdef SPI_INIT + volatile immap_t *immr = (immap_t *)CFG_IMMR; + + SPI_INIT; +#endif +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct soft_spi_slave *ss; + + if (!spi_cs_is_valid(bus, cs)) + return NULL; + + ss = malloc(sizeof(struct soft_spi_slave)); + if (!ss) + return NULL; + + ss->slave.bus = bus; + ss->slave.cs = cs; + ss->mode = mode; + + /* TODO: Use max_hz to limit the SCK rate */ + + return &ss->slave; +} + +void spi_free_slave(struct spi_slave *slave) +{ + struct soft_spi_slave *ss = to_soft_spi(slave); + + free(ss); +} + +int spi_claim_bus(struct spi_slave *slave) +{ +#ifdef CFG_IMMR + volatile immap_t *immr = (immap_t *)CFG_IMMR; +#endif + struct soft_spi_slave *ss = to_soft_spi(slave); + + /* + * Make sure the SPI clock is in idle state as defined for + * this slave. + */ + if (ss->mode & SPI_CPOL) + SPI_SCL(1); + else + SPI_SCL(0); + + return 0; +} + +void spi_release_bus(struct spi_slave *slave) +{ + /* Nothing to do */ +} + +/*----------------------------------------------------------------------- + * SPI transfer + * + * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks + * "bitlen" bits in the SPI MISO port. That's just the way SPI works. + * + * The source of the outgoing bits is the "dout" parameter and the + * destination of the input bits is the "din" parameter. Note that "dout" + * and "din" can point to the same memory location, in which case the + * input data overwrites the output data (since both are buffered by + * temporary variables, this is OK). + */ +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, + const void *dout, void *din, unsigned long flags) +{ +#ifdef CFG_IMMR + volatile immap_t *immr = (immap_t *)CFG_IMMR; +#endif + struct soft_spi_slave *ss = to_soft_spi(slave); + uchar tmpdin = 0; + uchar tmpdout = 0; + const u8 *txd = dout; + u8 *rxd = din; + int cpol = ss->mode & SPI_CPOL; + int cpha = ss->mode & SPI_CPHA; + unsigned int j; + + PRINTD("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n", + slave->bus, slave->cs, *(uint *)txd, *(uint *)rxd, bitlen); + + if (flags & SPI_XFER_BEGIN) + spi_cs_activate(slave); + + for(j = 0; j < bitlen; j++) { + /* + * Check if it is time to work on a new byte. + */ + if((j % 8) == 0) { + tmpdout = *txd++; + if(j != 0) { + *rxd++ = tmpdin; + } + tmpdin = 0; + } + + if (!cpha) + SPI_SCL(!cpol); + SPI_SDA(tmpdout & 0x80); + SPI_DELAY; + if (cpha) + SPI_SCL(!cpol); + else + SPI_SCL(cpol); + tmpdin <<= 1; + tmpdin |= SPI_READ; + tmpdout <<= 1; + SPI_DELAY; + if (cpha) + SPI_SCL(cpol); + } + /* + * If the number of bits isn't a multiple of 8, shift the last + * bits over to left-justify them. Then store the last byte + * read in. + */ + if((bitlen % 8) != 0) + tmpdin <<= 8 - (bitlen % 8); + *rxd++ = tmpdin; + + if (flags & SPI_XFER_END) + spi_cs_deactivate(slave); + + return(0); +} |