u-boot/drivers/spi/mpc8xxx_spi.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

165 lines
4.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2006 Ben Warren, Qstreams Networks Inc.
* With help from the common/soft_spi and arch/powerpc/cpu/mpc8260 drivers
*/
#include <common.h>
#include <malloc.h>
#include <spi.h>
#include <asm/mpc8xxx_spi.h>
#define SPI_EV_NE (0x80000000 >> 22) /* Receiver Not Empty */
#define SPI_EV_NF (0x80000000 >> 23) /* Transmitter Not Full */
#define SPI_MODE_LOOP (0x80000000 >> 1) /* Loopback mode */
#define SPI_MODE_REV (0x80000000 >> 5) /* Reverse mode - MSB first */
#define SPI_MODE_MS (0x80000000 >> 6) /* Always master */
#define SPI_MODE_EN (0x80000000 >> 7) /* Enable interface */
#define SPI_TIMEOUT 1000
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct spi_slave *slave;
if (!spi_cs_is_valid(bus, cs))
return NULL;
slave = spi_alloc_slave_base(bus, cs);
if (!slave)
return NULL;
/*
* TODO: Some of the code in spi_init() should probably move
* here, or into spi_claim_bus() below.
*/
return slave;
}
void spi_free_slave(struct spi_slave *slave)
{
free(slave);
}
void spi_init(void)
{
volatile spi8xxx_t *spi = &((immap_t *) (CONFIG_SYS_IMMR))->spi;
/*
* SPI pins on the MPC83xx are not muxed, so all we do is initialize
* some registers
*/
spi->mode = SPI_MODE_REV | SPI_MODE_MS | SPI_MODE_EN;
spi->mode = (spi->mode & 0xfff0ffff) | BIT(16); /* Use SYSCLK / 8
(16.67MHz typ.) */
spi->event = 0xffffffff; /* Clear all SPI events */
spi->mask = 0x00000000; /* Mask all SPI interrupts */
spi->com = 0; /* LST bit doesn't do anything, so disregard */
}
int spi_claim_bus(struct spi_slave *slave)
{
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
volatile spi8xxx_t *spi = &((immap_t *) (CONFIG_SYS_IMMR))->spi;
unsigned int tmpdout, tmpdin, event;
int numBlks = DIV_ROUND_UP(bitlen, 32);
int tm, isRead = 0;
unsigned char charSize = 32;
debug("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
slave->bus, slave->cs, *(uint *) dout, *(uint *) din, bitlen);
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave);
spi->event = 0xffffffff; /* Clear all SPI events */
/* handle data in 32-bit chunks */
while (numBlks--) {
tmpdout = 0;
charSize = (bitlen >= 32 ? 32 : bitlen);
/* Shift data so it's msb-justified */
tmpdout = *(u32 *) dout >> (32 - charSize);
/* The LEN field of the SPMODE register is set as follows:
*
* Bit length setting
* len <= 4 3
* 4 < len <= 16 len - 1
* len > 16 0
*/
spi->mode &= ~SPI_MODE_EN;
if (bitlen <= 16) {
if (bitlen <= 4)
spi->mode = (spi->mode & 0xff0fffff) |
(3 << 20);
else
spi->mode = (spi->mode & 0xff0fffff) |
((bitlen - 1) << 20);
} else {
spi->mode = (spi->mode & 0xff0fffff);
/* Set up the next iteration if sending > 32 bits */
bitlen -= 32;
dout += 4;
}
spi->mode |= SPI_MODE_EN;
spi->tx = tmpdout; /* Write the data out */
debug("*** spi_xfer: ... %08x written\n", tmpdout);
/*
* Wait for SPI transmit to get out
* or time out (1 second = 1000 ms)
* The NE event must be read and cleared first
*/
for (tm = 0, isRead = 0; tm < SPI_TIMEOUT; ++tm) {
event = spi->event;
if (event & SPI_EV_NE) {
tmpdin = spi->rx;
spi->event |= SPI_EV_NE;
isRead = 1;
*(u32 *) din = (tmpdin << (32 - charSize));
if (charSize == 32) {
/* Advance output buffer by 32 bits */
din += 4;
}
}
/*
* Only bail when we've had both NE and NF events.
* This will cause timeouts on RO devices, so maybe
* in the future put an arbitrary delay after writing
* the device. Arbitrary delays suck, though...
*/
if (isRead && (event & SPI_EV_NF))
break;
}
if (tm >= SPI_TIMEOUT)
puts("*** spi_xfer: Time out during SPI transfer");
debug("*** spi_xfer: transfer ended. Value=%08x\n", tmpdin);
}
if (flags & SPI_XFER_END)
spi_cs_deactivate(slave);
return 0;
}