From 3b51c719d305d4bfe8e99003f28d7cd48e0d9f4e Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Wed, 14 Jun 2006 00:22:50 +0000 Subject: [PATCH] Generalise three-wire interface to generic SPI interface. Update rtl8139 driver to instantiate an SPI interface with a three-wire device attached. --- src/drivers/bitbash/spi_bit.c | 165 +++++++++++++++++++++++++++++++ src/drivers/net/rtl8139.c | 96 +++++++++--------- src/drivers/nvs/threewire.c | 49 ++++----- src/include/gpxe/nvs/threewire.h | 102 ------------------- src/include/gpxe/spi.h | 132 +++++++++++++++++++++++++ src/include/gpxe/threewire.h | 65 ++++++++++++ 6 files changed, 427 insertions(+), 182 deletions(-) create mode 100644 src/drivers/bitbash/spi_bit.c delete mode 100644 src/include/gpxe/nvs/threewire.h create mode 100644 src/include/gpxe/spi.h create mode 100644 src/include/gpxe/threewire.h diff --git a/src/drivers/bitbash/spi_bit.c b/src/drivers/bitbash/spi_bit.c new file mode 100644 index 00000000..20ad412c --- /dev/null +++ b/src/drivers/bitbash/spi_bit.c @@ -0,0 +1,165 @@ +/* + * Copyright (C) 2006 Michael Brown . + * + * 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 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +/** @file + * + * SPI bit-bashing interface + * + */ + +/** Delay between SCLK changes and around SS changes */ +static void spi_delay ( void ) { + udelay ( SPI_UDELAY ); +} + +/** + * Select/deselect slave + * + * @v spi SPI bit-bashing interface + * @v slave Slave number + * @v state Slave select state + * + * @c state must be set to zero to select the specified slave, or to + * @c SPI_MODE_SSPOL to deselect the slave. + */ +static void spi_bit_set_slave_select ( struct spi_bit_basher *spibit, + unsigned int slave, + unsigned int state ) { + struct bit_basher *basher = &spibit->basher; + + state ^= ( spibit->spi.mode & SPI_MODE_SSPOL ); + DBG ( "Setting slave %d select %s\n", slave, + ( state ? "high" : "low" ) ); + + spi_delay(); + write_bit ( basher, SPI_BIT_SS ( slave ), state ); + spi_delay(); +} + +/** + * Select slave + * + * @v spi SPI interface + * @v slave Slave number + */ +static void spi_bit_select_slave ( struct spi_interface *spi, + unsigned int slave ) { + struct spi_bit_basher *spibit + = container_of ( spi, struct spi_bit_basher, spi ); + + spibit->slave = slave; + spi_bit_set_slave_select ( spibit, slave, 0 ); +} + +/** + * Deselect slave + * + * @v spi SPI interface + */ +static void spi_bit_deselect_slave ( struct spi_interface *spi ) { + struct spi_bit_basher *spibit + = container_of ( spi, struct spi_bit_basher, spi ); + + spi_bit_set_slave_select ( spibit, spibit->slave, SPI_MODE_SSPOL ); +} + +/** + * Transfer bits over SPI bit-bashing interface + * + * @v spi SPI interface + * @v data_out TX data buffer (or NULL) + * @v data_in RX data buffer (or NULL) + * @v len Length of transfer (in @b bits) + * + * This issues @c len clock cycles on the SPI bus, shifting out data + * from the @c data_out buffer to the MOSI line and shifting in data + * from the MISO line to the @c data_in buffer. If @c data_out is + * NULL, then the data sent will be all zeroes. If @c data_in is + * NULL, then the incoming data will be discarded. + */ +static void spi_bit_transfer ( struct spi_interface *spi, const void *data_out, + void *data_in, unsigned int len ) { + struct spi_bit_basher *spibit + = container_of ( spi, struct spi_bit_basher, spi ); + struct bit_basher *basher = &spibit->basher; + unsigned int sclk = ( ( spi->mode & SPI_MODE_CPOL ) ? 1 : 0 ); + unsigned int cpha = ( ( spi->mode & SPI_MODE_CPHA ) ? 1 : 0 ); + unsigned int offset; + unsigned int mask; + unsigned int bit; + int step; + + DBG ( "Transferring %d bits in mode %x\n", len, spi->mode ); + + for ( step = ( ( len * 2 ) - 1 ) ; step >= 0 ; step-- ) { + /* Calculate byte offset within data and bit mask */ + offset = ( step / 16 ); + mask = ( 1 << ( ( step % 16 ) / 2 ) ); + + /* Shift data in or out */ + if ( sclk == cpha ) { + const uint8_t *byte; + + /* Shift data out */ + if ( data_out ) { + byte = ( data_out + offset ); + bit = ( *byte & mask ); + } else { + bit = 0; + } + write_bit ( basher, SPI_BIT_MOSI, bit ); + } else { + uint8_t *byte; + + /* Shift data in */ + bit = read_bit ( basher, SPI_BIT_MISO ); + if ( data_in ) { + byte = ( data_in + offset ); + *byte &= ~mask; + *byte |= ( bit & mask ); + } + } + + /* Toggle clock line */ + spi_delay(); + sclk = ~sclk; + write_bit ( basher, SPI_BIT_SCLK, sclk ); + } +} + +/** + * Initialise SPI bit-bashing interface + * + * @v spibit SPI bit-bashing interface + */ +void init_spi_bit_basher ( struct spi_bit_basher *spibit ) { + assert ( &spibit->basher.read != NULL ); + assert ( &spibit->basher.write != NULL ); + spibit->spi.select_slave = spi_bit_select_slave; + spibit->spi.deselect_slave = spi_bit_deselect_slave; + spibit->spi.transfer = spi_bit_transfer; +} diff --git a/src/drivers/net/rtl8139.c b/src/drivers/net/rtl8139.c index 4e17080c..d42d3c2d 100644 --- a/src/drivers/net/rtl8139.c +++ b/src/drivers/net/rtl8139.c @@ -77,7 +77,8 @@ #include #include #include -#include +#include +#include #define TX_RING_SIZE 4 @@ -92,10 +93,11 @@ struct rtl8139_rx { }; struct rtl8139_nic { - struct threewire eeprom; unsigned short ioaddr; struct rtl8139_tx tx; struct rtl8139_rx rx; + struct spi_bit_basher spibit; + struct threewire_device eeprom; }; /* Tuning Parameters */ @@ -192,8 +194,8 @@ enum RxConfigBits { }; /* EEPROM access */ -#define EE_MODE_PROGRAM 0x80 -#define EE_MODE_NORMAL 0x00 +#define EE_M1 0x80 /* Mode select bit 1 */ +#define EE_M0 0x40 /* Mode select bit 0 */ #define EE_CS 0x08 /* EEPROM chip select */ #define EE_SK 0x04 /* EEPROM shift clock */ #define EE_DI 0x02 /* Data in */ @@ -202,51 +204,40 @@ enum RxConfigBits { /* Offsets within EEPROM (these are word offsets) */ #define EE_MAC 7 -static inline struct rtl8139_nic * three_to_rtl ( struct threewire *three ) { - return container_of ( three, struct rtl8139_nic, eeprom ); +static inline struct rtl8139_nic * +basher_to_rtl ( struct bit_basher *basher ) { + return container_of ( basher, struct rtl8139_nic, spibit.basher ); } -static void rtl_setcs ( struct threewire *three, int cs ) { - struct rtl8139_nic *rtl = three_to_rtl ( three ); - unsigned int eereg; - - eereg = cs ? ( EE_MODE_PROGRAM | EE_CS ) : ( EE_MODE_NORMAL ); - outb ( eereg, rtl->ioaddr + Cfg9346 ); -} - -static void rtl_setsk ( struct threewire *three, int sk ) { - struct rtl8139_nic *rtl = three_to_rtl ( three ); - unsigned int eereg; - - eereg = inb ( rtl->ioaddr + Cfg9346 ); - eereg = ( eereg & ~EE_SK ) | ( sk ? EE_SK : 0 ); - outb ( eereg, rtl->ioaddr + Cfg9346 ); -} - -static void rtl_setdi ( struct threewire *three, int di ) { - struct rtl8139_nic *rtl = three_to_rtl ( three ); - unsigned int eereg; - - eereg = inb ( rtl->ioaddr + Cfg9346 ); - eereg = ( eereg & ~EE_DI ) | ( di ? EE_DI : 0 ); - outb ( eereg, rtl->ioaddr + Cfg9346 ); -} - -static int rtl_getdo ( struct threewire *three ) { - struct rtl8139_nic *rtl = three_to_rtl ( three ); - unsigned int eereg; - - eereg = ( inb ( rtl->ioaddr + Cfg9346 ) & EE_DO ); - return eereg; -} - -static struct threewire_operations rtl_three_ops = { - .setcs = rtl_setcs, - .setsk = rtl_setsk, - .setdi = rtl_setdi, - .getdo = rtl_getdo, +static const uint8_t rtl_ee_bits[] = { + [SPI_BIT_SCLK] = EE_SK, + [SPI_BIT_MOSI] = EE_DI, + [SPI_BIT_MISO] = EE_DO, + [SPI_BIT_SS(0)] = ( EE_CS | EE_M1 ), }; +static int rtl_spi_read_bit ( struct bit_basher *basher, + unsigned int bit_id ) { + struct rtl8139_nic *rtl = basher_to_rtl ( basher ); + uint8_t mask = rtl_ee_bits[bit_id]; + uint8_t eereg; + + eereg = inb ( rtl->ioaddr + Cfg9346 ); + return ( eereg & mask ); +} + +static void rtl_spi_write_bit ( struct bit_basher *basher, + unsigned int bit_id, unsigned long data ) { + struct rtl8139_nic *rtl = basher_to_rtl ( basher ); + uint8_t mask = rtl_ee_bits[bit_id]; + uint8_t eereg; + + eereg = inb ( rtl->ioaddr + Cfg9346 ); + eereg &= ~mask; + eereg |= ( data & mask ); + outb ( eereg, rtl->ioaddr + Cfg9346 ); +} + /** * Set up for EEPROM access * @@ -255,14 +246,20 @@ static struct threewire_operations rtl_three_ops = { static void rtl_init_eeprom ( struct rtl8139_nic *rtl ) { int ee9356; + /* Initialise three-wire bus */ + rtl->spibit.basher.read = rtl_spi_read_bit; + rtl->spibit.basher.write = rtl_spi_write_bit; + rtl->spibit.spi.mode = SPI_MODE_THREEWIRE; + init_spi_bit_basher ( &rtl->spibit ); + + /* Detect EEPROM type and initialise three-wire device */ ee9356 = ( inw ( rtl->ioaddr + RxConfig ) & Eeprom9356 ); DBG ( "EEPROM is an %s\n", ee9356 ? "AT93C56" : "AT93C46" ); - rtl->eeprom.ops = &rtl_three_ops; rtl->eeprom.adrsize = ( ee9356 ? AT93C56_ORG16_ADRSIZE : AT93C46_ORG16_ADRSIZE ); rtl->eeprom.datasize = ( ee9356 ? AT93C56_ORG16_DATASIZE : AT93C46_ORG16_DATASIZE ); - rtl->eeprom.udelay = 1; + rtl->eeprom.spi = &rtl->spibit.spi; } /** @@ -279,9 +276,8 @@ static void rtl_read_mac ( struct rtl8139_nic *rtl, uint8_t *mac_addr ) { int i; DBG ( "MAC address is " ); - for ( i = 0 ; i < ( ETH_ALEN / 2 ) ; i++ ) { - u.word = cpu_to_le16 ( threewire_read ( &rtl->eeprom, - EE_MAC + i ) ); + for ( i = EE_MAC ; i < ( EE_MAC + ( ETH_ALEN / 2 ) ) ; i++ ) { + u.word = cpu_to_le16 ( threewire_read ( &rtl->eeprom, i ) ); *mac_addr++ = u.bytes[0]; *mac_addr++ = u.bytes[1]; DBG ( "%02x%02x", u.bytes[0], u.bytes[1] ); diff --git a/src/drivers/nvs/threewire.c b/src/drivers/nvs/threewire.c index 4673606d..92f9a24b 100644 --- a/src/drivers/nvs/threewire.c +++ b/src/drivers/nvs/threewire.c @@ -16,53 +16,42 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include -#include +#include +#include +#include +#include /** @file * - * Three-wire serial interface + * Three-wire serial devices * */ /** * Read from a three-wire device * - * @v three Three-wire interface + * @v three Three-wire device * @v address Address * @ret data Data */ -unsigned long threewire_read ( struct threewire *three, +unsigned long threewire_read ( struct threewire_device *three, unsigned long address ) { - struct threewire_operations *ops = three->ops; - unsigned long command; - unsigned long data; - int i; + struct spi_interface *spi = three->spi; + uint32_t data; + + /* Activate chip select line */ + spi->select_slave ( spi, three->slave ); - ops->setcs ( three, 1 ); - /* Send command and address */ - command = threewire_cmd_read ( three, address ); - for ( i = ( threewire_cmd_len ( three ) - 1 ) ; i >= 0 ; i-- ) { - ops->setdi ( three, ( command >> i ) & 0x1 ); - udelay ( three->udelay ); - ops->setsk ( three, 1 ); - udelay ( three->udelay ); - ops->setsk ( three, 0 ); - } - + data = cpu_to_le32 ( threewire_cmd_read ( three, address ) ); + spi->transfer ( spi, &data, NULL, threewire_cmd_len ( three ) ); + /* Read back data */ data = 0; - for ( i = three->datasize ; i ; i-- ) { - udelay ( three->udelay ); - ops->setsk ( three, 1 ); - udelay ( three->udelay ); - data <<= 1; - data |= ops->getdo ( three ); - ops->setsk ( three, 0 ); - } + spi->transfer ( spi, NULL, &data, three->datasize ); - ops->setcs ( three, 0 ); + /* Deactivate chip select line */ + spi->deselect_slave ( spi ); - return data; + return le32_to_cpu ( data );; } diff --git a/src/include/gpxe/nvs/threewire.h b/src/include/gpxe/nvs/threewire.h deleted file mode 100644 index a0bb2fd3..00000000 --- a/src/include/gpxe/nvs/threewire.h +++ /dev/null @@ -1,102 +0,0 @@ -#ifndef _GPXE_NVS_THREEWIRE_H -#define _GPXE_NVS_THREEWIRE_H - -/** @file - * - * Three-wire serial interface - * - */ - -struct threewire; - -/** Three-wire interface methods */ -struct threewire_operations { - /** - * Set status of Chip Select line - * - * @v three Three-wire interface - * @v cs New status for chip select line - */ - void ( * setcs ) ( struct threewire *three, int cs ); - /** - * Set status of Serial Clock line - * - * @v three Three-wire interface - * @v sk New status for serial clock line - */ - void ( * setsk ) ( struct threewire *three, int sk ); - /** - * Set status of Data Input line - * - * @v three Three-wire interface - * @v di New status for data input line - */ - void ( * setdi ) ( struct threewire *three, int di ); - /** - * Get status of Data Output line - * - * @v three Three-wire interface - * @ret do Status of data output line - */ - int ( * getdo ) ( struct threewire *three ); -}; - -/** - * A three-wire serial interface - * - * This interface consists of a clock line (SK), data input (DI) and - * data output (DO). There is also a chip select line (CS) which is - * integral to the operation of the device, but Atmel still calls it a - * three-wire interface. - * - */ -struct threewire { - /** Interface methods */ - struct threewire_operations *ops; - /** Address size (in bits) */ - unsigned int adrsize; - /** Data size (in bits) */ - unsigned int datasize; - /** Delay between SK transitions (in us) */ - unsigned int udelay; -}; - -/** - * Calculate read command for a specified address - * - * @v three Three-wire interface - * @v address Address - * @ret cmd Command - */ -static inline __attribute__ (( always_inline )) unsigned long -threewire_cmd_read ( struct threewire *three, unsigned long address ) { - return ( ( 0x6 << three->adrsize ) | address ); -} - -/** - * Calculate command length - * - * @v three Three-wire interface - * @ret len Command length, in bits - */ -static inline __attribute__ (( always_inline )) int -threewire_cmd_len ( struct threewire *three ) { - return ( three->adrsize + 3 ); -} - -/* Constants for some standard parts */ -#define AT93C46_ORG8_ADRSIZE 7 -#define AT93C46_ORG8_DATASIZE 8 -#define AT93C46_ORG16_ADRSIZE 6 -#define AT93C46_ORG16_DATASIZE 16 -#define AT93C46_UDELAY 1 -#define AT93C56_ORG8_ADRSIZE 9 -#define AT93C56_ORG8_DATASIZE 8 -#define AT93C56_ORG16_ADRSIZE 8 -#define AT93C56_ORG16_DATASIZE 16 -#define AT93C56_UDELAY 1 - -extern unsigned long threewire_read ( struct threewire *three, - unsigned long address ); - -#endif /* _GPXE_NVS_THREEWIRE_H */ diff --git a/src/include/gpxe/spi.h b/src/include/gpxe/spi.h new file mode 100644 index 00000000..3ea85846 --- /dev/null +++ b/src/include/gpxe/spi.h @@ -0,0 +1,132 @@ +#ifndef _GPXE_SPI_H +#define _GPXE_SPI_H + +/** @file + * + * SPI interface + * + */ + +#include + +/** An SPI interface */ +struct spi_interface { + /** SPI interface mode + * + * This is the bitwise OR of zero or more of @c SPI_MODE_CPHA + * and @c SPI_MODE_CPOL. It is also the number conventionally + * used to describe the SPI interface mode. For example, SPI + * mode 1 is the mode in which CPOL=0 and CPHA=1, which + * therefore corresponds to a mode value of (0|SPI_MODE_CPHA) + * which, happily, equals 1. + */ + unsigned int mode; + /** + * Select slave + * + * @v spi SPI interface + * @v slave Slave number + */ + void ( * select_slave ) ( struct spi_interface *spi, + unsigned int slave ); + /** + * Deselect slave + * + * @v spi SPI interface + */ + void ( * deselect_slave ) ( struct spi_interface *spi ); + /** + * Transfer bits over SPI bit-bashing interface + * + * @v spi SPI interface + * @v data_out TX data buffer (or NULL) + * @v data_in RX data buffer (or NULL) + * @v len Length of transfer (in @b bits) + */ + void ( * transfer ) ( struct spi_interface *spi, const void *data_out, + void *data_in, unsigned int len ); +}; + +/** Clock phase (CPHA) mode bit + * + * Phase 0 is sample on rising edge, shift data on falling edge. + * + * Phase 1 is shift data on rising edge, sample data on falling edge. + */ +#define SPI_MODE_CPHA 0x01 + +/** Clock polarity (CPOL) mode bit + * + * This bit reflects the idle state of the clock line (SCLK). + */ +#define SPI_MODE_CPOL 0x02 + +/** Slave select polarity mode bit + * + * This bit reflects that active state of the slave select lines. It + * is not part of the normal SPI mode number (which covers only @c + * SPI_MODE_CPOL and @c SPI_MODE_CPHA), but is included here for + * convenience. + */ +#define SPI_MODE_SSPOL 0x10 + +/** Microwire-compatible mode + * + * This is SPI mode 1 (i.e. CPOL=0, CPHA=1), and is compatible with + * the original Microwire protocol. + */ +#define SPI_MODE_MICROWIRE 1 + +/** Microwire/Plus-compatible mode + * + * This is SPI mode 0 (i.e. CPOL=0, CPHA=0), and is compatible with + * the Microwire/Plus protocol + */ +#define SPI_MODE_MICROWIRE_PLUS 0 + +/** Threewire-compatible mode + * + * This mode is compatible with Atmel's series of "three-wire" + * interfaces. + */ +#define SPI_MODE_THREEWIRE ( SPI_MODE_MICROWIRE_PLUS | SPI_MODE_SSPOL ) + +/** A bit-bashing SPI interface */ +struct spi_bit_basher { + /** SPI interface */ + struct spi_interface spi; + /** Bit-bashing interface */ + struct bit_basher basher; + /** Currently selected slave + * + * Valid only when a slave is actually selected. + */ + unsigned int slave; +}; + +/** Bit indices used for SPI bit-bashing interface */ +enum { + /** Serial clock */ + SPI_BIT_SCLK = 0, + /** Master Out Slave In */ + SPI_BIT_MOSI, + /** Master In Slave Out */ + SPI_BIT_MISO, + /** Slave 0 select */ + SPI_BIT_SS0, +}; + +/** + * Determine bit index for a particular slave + * + * @v slave Slave number + * @ret index Bit index (i.e. SPI_BIT_SSN, where N=slave) + */ +#define SPI_BIT_SS( slave ) ( SPI_BIT_SS0 + (slave) ) + +/** Delay between SCLK transitions */ +#define SPI_UDELAY 1 + +extern void init_spi_bit_basher ( struct spi_bit_basher *spibit ); + +#endif /* _GPXE_SPI_H */ diff --git a/src/include/gpxe/threewire.h b/src/include/gpxe/threewire.h new file mode 100644 index 00000000..d9d88567 --- /dev/null +++ b/src/include/gpxe/threewire.h @@ -0,0 +1,65 @@ +#ifndef _GPXE_THREEWIRE_H +#define _GPXE_THREEWIRE_H + +/** @file + * + * Three-wire serial interface + * + * The Atmel three-wire interface is a subset of the (newer) SPI + * interface, and is implemented here as a layer on top of the SPI + * support. + */ + +struct spi_interface; + +/** A three-wire device */ +struct threewire_device { + /** SPI interface to which device is attached */ + struct spi_interface *spi; + /** SPI slave number */ + unsigned int slave; + /** Address size (in bits) */ + unsigned int adrsize; + /** Data size (in bits) */ + unsigned int datasize; +}; + +/** + * Calculate read command for a specified address + * + * @v three Three-wire interface + * @v address Address + * @ret cmd Command + */ +static inline __attribute__ (( always_inline )) unsigned long +threewire_cmd_read ( struct threewire_device *three, unsigned long address ) { + return ( ( 0x6 << three->adrsize ) | address ); +} + +/** + * Calculate command length + * + * @v three Three-wire interface + * @ret len Command length, in bits + */ +static inline __attribute__ (( always_inline )) unsigned int +threewire_cmd_len ( struct threewire_device *three ) { + return ( three->adrsize + 3 ); +} + +/* Constants for some standard parts */ +#define AT93C46_ORG8_ADRSIZE 7 +#define AT93C46_ORG8_DATASIZE 8 +#define AT93C46_ORG16_ADRSIZE 6 +#define AT93C46_ORG16_DATASIZE 16 +#define AT93C46_UDELAY 1 +#define AT93C56_ORG8_ADRSIZE 9 +#define AT93C56_ORG8_DATASIZE 8 +#define AT93C56_ORG16_ADRSIZE 8 +#define AT93C56_ORG16_DATASIZE 16 +#define AT93C56_UDELAY 1 + +extern unsigned long threewire_read ( struct threewire_device *three, + unsigned long address ); + +#endif /* _GPXE_THREEWIRE_H */