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/* SPDX-License-Identifier: GPL-2.0-only */
/* This file is part of the coreboot project. */
#include <device/mmio.h>
#include <assert.h>
#include <boot_device.h>
#include <console/console.h>
#include <soc/clk.h>
#include <soc/gpio.h>
#include <soc/spi.h>
#include <symbols.h>
#if defined(CONFIG_DEBUG_SPI) && CONFIG_DEBUG_SPI
# define DEBUG_SPI(x,...) printk(BIOS_DEBUG, "EXYNOS_SPI: " x)
#else
# define DEBUG_SPI(x,...)
#endif
static void exynos_spi_rx_tx(struct exynos_spi *regs, int todo,
void *dinp, void const *doutp, int i)
{
int rx_lvl, tx_lvl;
unsigned int *rxp = (unsigned int *)(dinp + (i * (32 * 1024)));
unsigned int out_bytes, in_bytes;
// TODO In current implementation, every read/write must be aligned to
// 4 bytes, otherwise you may get timeout or other unexpected results.
ASSERT(todo % 4 == 0);
out_bytes = in_bytes = todo;
setbits32(®s->ch_cfg, SPI_CH_RST);
clrbits32(®s->ch_cfg, SPI_CH_RST);
write32(®s->pkt_cnt, ((todo * 8) / 32) | SPI_PACKET_CNT_EN);
while (in_bytes) {
uint32_t spi_sts;
int temp;
spi_sts = read32(®s->spi_sts);
rx_lvl = ((spi_sts >> 15) & 0x7f);
tx_lvl = ((spi_sts >> 6) & 0x7f);
while (tx_lvl < 32 && out_bytes) {
// TODO The "writing" (tx) is not supported now; that's
// why we write garbage to keep driving FIFO clock.
temp = 0xffffffff;
write32(®s->tx_data, temp);
out_bytes -= 4;
tx_lvl += 4;
}
while (rx_lvl >= 4 && in_bytes) {
temp = read32(®s->rx_data);
if (rxp)
*rxp++ = temp;
in_bytes -= 4;
rx_lvl -= 4;
}
}
}
/* set up SPI channel */
int exynos_spi_open(struct exynos_spi *regs)
{
/* set the spi1 GPIO */
/* set pktcnt and enable it */
write32(®s->pkt_cnt, 4 | SPI_PACKET_CNT_EN);
/* set FB_CLK_SEL */
write32(®s->fb_clk, SPI_FB_DELAY_180);
/* set CH_WIDTH and BUS_WIDTH as word */
setbits32(®s->mode_cfg,
SPI_MODE_CH_WIDTH_WORD | SPI_MODE_BUS_WIDTH_WORD);
clrbits32(®s->ch_cfg, SPI_CH_CPOL_L); /* CPOL: active high */
/* clear rx and tx channel if set previously */
clrbits32(®s->ch_cfg, SPI_RX_CH_ON | SPI_TX_CH_ON);
setbits32(®s->swap_cfg,
SPI_RX_SWAP_EN | SPI_RX_BYTE_SWAP | SPI_RX_HWORD_SWAP);
/* do a soft reset */
setbits32(®s->ch_cfg, SPI_CH_RST);
clrbits32(®s->ch_cfg, SPI_CH_RST);
/* now set rx and tx channel ON */
setbits32(®s->ch_cfg, SPI_RX_CH_ON | SPI_TX_CH_ON | SPI_CH_HS_EN);
return 0;
}
int exynos_spi_read(struct exynos_spi *regs, void *dest, u32 len, u32 off)
{
int upto, todo;
int i;
clrbits32(®s->cs_reg, SPI_SLAVE_SIG_INACT); /* CS low */
/* Send read instruction (0x3h) followed by a 24 bit addr */
write32(®s->tx_data, (SF_READ_DATA_CMD << 24) | off);
/* waiting for TX done */
while (!(read32(®s->spi_sts) & SPI_ST_TX_DONE));
for (upto = 0, i = 0; upto < len; upto += todo, i++) {
todo = MIN(len - upto, (1 << 15));
exynos_spi_rx_tx(regs, todo, dest, (void *)(off), i);
}
setbits32(®s->cs_reg, SPI_SLAVE_SIG_INACT);/* make the CS high */
return len;
}
int exynos_spi_close(struct exynos_spi *regs)
{
/*
* Let put controller mode to BYTE as
* SPI driver does not support WORD mode yet
*/
clrbits32(®s->mode_cfg,
SPI_MODE_CH_WIDTH_WORD | SPI_MODE_BUS_WIDTH_WORD);
write32(®s->swap_cfg, 0);
/*
* Flush spi tx, rx fifos and reset the SPI controller
* and clear rx/tx channel
*/
clrsetbits32(®s->ch_cfg, SPI_CH_HS_EN, SPI_CH_RST);
clrbits32(®s->ch_cfg, SPI_CH_RST);
clrbits32(®s->ch_cfg, SPI_TX_CH_ON | SPI_RX_CH_ON);
return 0;
}
static struct exynos_spi *boot_slave_regs;
static ssize_t exynos_spi_readat(const struct region_device *rdev, void *dest,
size_t offset, size_t count)
{
int bytes;
DEBUG_SPI("exynos_spi_cbfs_read(%u)\n", count);
exynos_spi_open(boot_slave_regs);
bytes = exynos_spi_read(boot_slave_regs, dest, count, offset);
exynos_spi_close(boot_slave_regs);
return bytes;
}
static void *exynos_spi_map(const struct region_device *rdev,
size_t offset, size_t count)
{
DEBUG_SPI("exynos_spi_cbfs_map\n");
// exynos: spi_rx_tx may work in 4 byte-width-transmission mode and
// requires buffer memory address to be aligned.
if (count % 4)
count += 4 - (count % 4);
return mmap_helper_rdev_mmap(rdev, offset, count);
}
static const struct region_device_ops exynos_spi_ops = {
.mmap = exynos_spi_map,
.munmap = mmap_helper_rdev_munmap,
.readat = exynos_spi_readat,
};
static struct mmap_helper_region_device mdev =
MMAP_HELPER_REGION_INIT(&exynos_spi_ops, 0, CONFIG_ROM_SIZE);
void exynos_init_spi_boot_device(void)
{
boot_slave_regs = (void *)EXYNOS5_SPI1_BASE;
mmap_helper_device_init(&mdev, _cbfs_cache, REGION_SIZE(cbfs_cache));
}
const struct region_device *exynos_spi_boot_device(void)
{
return &mdev.rdev;
}
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