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d255bb0e78
This patch gets rid of the spi_chipsel table and adds a handful of new
functions that makes the SPI layer cleaner and more flexible.
Instead of the spi_chipsel table, each board that wants to use SPI
gets to implement three hooks:
* spi_cs_activate(): Activates the chipselect for a given slave
* spi_cs_deactivate(): Deactivates the chipselect for a given slave
* spi_cs_is_valid(): Determines if the given bus/chipselect
combination can be activated.
Not all drivers may need those extra functions however. If that's the
case, the board code may just leave them out (assuming they know what
the driver needs) or rely on the linker to strip them out (assuming
--gc-sections is being used.)
To set up communication parameters for a given slave, the driver needs
to call spi_setup_slave(). This returns a pointer to an opaque
spi_slave struct which must be passed as a parameter to subsequent SPI
calls. This struct can be freed by calling spi_free_slave(), but most
driver probably don't want to do this.
Before starting one or more SPI transfers, the driver must call
spi_claim_bus() to gain exclusive access to the SPI bus and initialize
the hardware. When all transfers are done, the driver must call
spi_release_bus() to make the bus available to others, and possibly
shut down the SPI controller hardware.
spi_xfer() behaves mostly the same as before, but it now takes a
spi_slave parameter instead of a spi_chipsel function pointer. It also
got a new parameter, flags, which is used to specify chip select
behaviour. This may be extended with other flags in the future.
This patch has been build-tested on all powerpc and arm boards
involved. I have not tested NIOS since I don't have a toolchain for it
installed, so I expect some breakage there even though I've tried
fixing up everything I could find by visual inspection.
I have run-time tested this on AVR32 ATNGW100 using the atmel_spi and
DataFlash drivers posted as a follow-up. I'd like some help testing
other boards that use the existing SPI API.
But most of all, I'd like some comments on the new API. Is this stuff
usable for everyone? If not, why?
Changed in v4:
- Build fixes for various boards, drivers and commands
- Provide common struct spi_slave definition that can be extended by
drivers
- Pass a struct spi_slave * to spi_cs_activate and spi_cs_deactivate
- Make default bus and mode build-time configurable
- Override default SPI bus ID and mode on mx32ads and imx31_litekit.
Changed in v3:
- Add opaque struct spi_slave for controller-specific data associated
with a slave.
- Add spi_claim_bus() and spi_release_bus()
- Add spi_free_slave()
- spi_setup() is now called spi_setup_slave() and returns a
struct spi_slave
- soft_spi now supports four SPI modes (CPOL|CPHA)
- Add bus parameter to spi_setup_slave()
- Convert the new i.MX32 SPI driver
- Convert the new MC13783 RTC driver
Changed in v2:
- Convert the mpc8xxx_spi driver and the mpc8349emds board to the
new API.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Tested-by: Guennadi Liakhovetski <lg@denx.de>
147 lines
3.6 KiB
C
147 lines
3.6 KiB
C
/*
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* (C) Copyright 2002
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* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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/*
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* SPI Read/Write Utilities
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*/
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#include <common.h>
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#include <command.h>
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#include <spi.h>
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/*-----------------------------------------------------------------------
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* Definitions
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*/
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#ifndef MAX_SPI_BYTES
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# define MAX_SPI_BYTES 32 /* Maximum number of bytes we can handle */
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#endif
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#ifndef CONFIG_DEFAULT_SPI_BUS
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# define CONFIG_DEFAULT_SPI_BUS 0
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#endif
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#ifndef CONFIG_DEFAULT_SPI_MODE
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# define CONFIG_DEFAULT_SPI_MODE SPI_MODE_0
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#endif
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/*
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* Values from last command.
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*/
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static unsigned int device;
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static int bitlen;
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static uchar dout[MAX_SPI_BYTES];
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static uchar din[MAX_SPI_BYTES];
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/*
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* SPI read/write
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*
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* Syntax:
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* spi {dev} {num_bits} {dout}
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* {dev} is the device number for controlling chip select (see TBD)
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* {num_bits} is the number of bits to send & receive (base 10)
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* {dout} is a hexadecimal string of data to send
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* The command prints out the hexadecimal string received via SPI.
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*/
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int do_spi (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
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{
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struct spi_slave *slave;
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char *cp = 0;
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uchar tmp;
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int j;
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int rcode = 0;
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/*
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* We use the last specified parameters, unless new ones are
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* entered.
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*/
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if ((flag & CMD_FLAG_REPEAT) == 0)
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{
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if (argc >= 2)
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device = simple_strtoul(argv[1], NULL, 10);
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if (argc >= 3)
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bitlen = simple_strtoul(argv[2], NULL, 10);
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if (argc >= 4) {
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cp = argv[3];
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for(j = 0; *cp; j++, cp++) {
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tmp = *cp - '0';
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if(tmp > 9)
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tmp -= ('A' - '0') - 10;
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if(tmp > 15)
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tmp -= ('a' - 'A');
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if(tmp > 15) {
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printf("Hex conversion error on %c, giving up.\n", *cp);
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return 1;
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}
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if((j % 2) == 0)
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dout[j / 2] = (tmp << 4);
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else
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dout[j / 2] |= tmp;
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}
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}
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}
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if ((bitlen < 0) || (bitlen > (MAX_SPI_BYTES * 8))) {
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printf("Invalid bitlen %d, giving up.\n", bitlen);
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return 1;
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}
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/* FIXME: Make these parameters run-time configurable */
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slave = spi_setup_slave(CONFIG_DEFAULT_SPI_BUS, device, 1000000,
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CONFIG_DEFAULT_SPI_MODE);
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if (!slave) {
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printf("Invalid device %d, giving up.\n", device);
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return 1;
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}
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debug ("spi chipsel = %08X\n", device);
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spi_claim_bus(slave);
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if(spi_xfer(slave, bitlen, dout, din,
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SPI_XFER_BEGIN | SPI_XFER_END) != 0) {
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printf("Error with the SPI transaction.\n");
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rcode = 1;
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} else {
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cp = (char *)din;
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for(j = 0; j < ((bitlen + 7) / 8); j++) {
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printf("%02X", *cp++);
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}
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printf("\n");
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}
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spi_release_bus(slave);
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spi_free_slave(slave);
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return rcode;
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}
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/***************************************************/
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U_BOOT_CMD(
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sspi, 5, 1, do_spi,
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"sspi - SPI utility commands\n",
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"<device> <bit_len> <dout> - Send <bit_len> bits from <dout> out the SPI\n"
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"<device> - Identifies the chip select of the device\n"
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"<bit_len> - Number of bits to send (base 10)\n"
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"<dout> - Hexadecimal string that gets sent\n"
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);
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