u-boot/cmd/spi.c

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// SPDX-License-Identifier: GPL-2.0+
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/*
* (C) Copyright 2002
* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com
*/
/*
* SPI Read/Write Utilities
*/
#include <common.h>
#include <command.h>
#include <dm.h>
#include <errno.h>
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#include <spi.h>
/*-----------------------------------------------------------------------
* Definitions
*/
#ifndef MAX_SPI_BYTES
# define MAX_SPI_BYTES 32 /* Maximum number of bytes we can handle */
#endif
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/*
* Values from last command.
*/
static unsigned int bus;
static unsigned int cs;
static unsigned int mode;
static unsigned int freq;
SPI API improvements 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>
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static int bitlen;
static uchar dout[MAX_SPI_BYTES];
static uchar din[MAX_SPI_BYTES];
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static int do_spi_xfer(int bus, int cs)
{
struct spi_slave *slave;
int ret = 0;
#ifdef CONFIG_DM_SPI
char name[30], *str;
struct udevice *dev;
snprintf(name, sizeof(name), "generic_%d:%d", bus, cs);
str = strdup(name);
if (!str)
return -ENOMEM;
ret = spi_get_bus_and_cs(bus, cs, freq, mode, "spi_generic_drv",
str, &dev, &slave);
if (ret)
return ret;
#else
slave = spi_setup_slave(bus, cs, freq, mode);
if (!slave) {
printf("Invalid device %d:%d\n", bus, cs);
return -EINVAL;
}
#endif
ret = spi_claim_bus(slave);
if (ret)
goto done;
ret = spi_xfer(slave, bitlen, dout, din,
SPI_XFER_BEGIN | SPI_XFER_END);
#ifndef CONFIG_DM_SPI
/* We don't get an error code in this case */
if (ret)
ret = -EIO;
#endif
if (ret) {
printf("Error %d during SPI transaction\n", ret);
} else {
int j;
for (j = 0; j < ((bitlen + 7) / 8); j++)
printf("%02X", din[j]);
printf("\n");
}
done:
spi_release_bus(slave);
#ifndef CONFIG_DM_SPI
spi_free_slave(slave);
#endif
return ret;
}
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/*
* SPI read/write
*
* Syntax:
* spi {dev} {num_bits} {dout}
* {dev} is the device number for controlling chip select (see TBD)
* {num_bits} is the number of bits to send & receive (base 10)
* {dout} is a hexadecimal string of data to send
* The command prints out the hexadecimal string received via SPI.
*/
int do_spi (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
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{
char *cp = 0;
uchar tmp;
int j;
/*
* We use the last specified parameters, unless new ones are
* entered.
*/
if (freq == 0)
freq = 1000000;
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if ((flag & CMD_FLAG_REPEAT) == 0)
{
if (argc >= 2) {
mode = CONFIG_DEFAULT_SPI_MODE;
bus = simple_strtoul(argv[1], &cp, 10);
if (*cp == ':') {
cs = simple_strtoul(cp+1, &cp, 10);
} else {
cs = bus;
bus = CONFIG_DEFAULT_SPI_BUS;
}
if (*cp == '.')
mode = simple_strtoul(cp+1, &cp, 10);
if (*cp == '@')
freq = simple_strtoul(cp+1, &cp, 10);
}
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if (argc >= 3)
bitlen = simple_strtoul(argv[2], NULL, 10);
if (argc >= 4) {
cp = argv[3];
for(j = 0; *cp; j++, cp++) {
tmp = *cp - '0';
if(tmp > 9)
tmp -= ('A' - '0') - 10;
if(tmp > 15)
tmp -= ('a' - 'A');
if(tmp > 15) {
printf("Hex conversion error on %c\n", *cp);
return 1;
}
if((j % 2) == 0)
dout[j / 2] = (tmp << 4);
else
dout[j / 2] |= tmp;
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}
}
}
if ((bitlen < 0) || (bitlen > (MAX_SPI_BYTES * 8))) {
printf("Invalid bitlen %d\n", bitlen);
return 1;
}
if (do_spi_xfer(bus, cs))
SPI API improvements 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>
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return 1;
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return 0;
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}
/***************************************************/
U_BOOT_CMD(
sspi, 5, 1, do_spi,
"SPI utility command",
"[<bus>:]<cs>[.<mode>][@<freq>] <bit_len> <dout> - Send and receive bits\n"
"<bus> - Identifies the SPI bus\n"
"<cs> - Identifies the chip select\n"
"<mode> - Identifies the SPI mode to use\n"
"<freq> - Identifies the SPI bus frequency in Hz\n"
"<bit_len> - Number of bits to send (base 10)\n"
"<dout> - Hexadecimal string that gets sent"
);