diff options
Diffstat (limited to 'src/soc/samsung/exynos5250/spi.c')
| -rw-r--r-- | src/soc/samsung/exynos5250/spi.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/src/soc/samsung/exynos5250/spi.c b/src/soc/samsung/exynos5250/spi.c new file mode 100644 index 0000000000..33ec6984db --- /dev/null +++ b/src/soc/samsung/exynos5250/spi.c @@ -0,0 +1,213 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2011 Samsung Electronics + * Copyright 2013 Google Inc. + * + * 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; version 2 of the License. + * + * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <assert.h> +#include <stdlib.h> +#include <arch/io.h> +#include <console/console.h> +#include "clk.h" +#include "gpio.h" +#include "spi.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; + setbits_le32(®s->ch_cfg, SPI_CH_RST); + clrbits_le32(®s->ch_cfg, SPI_CH_RST); + writel(((todo * 8) / 32) | SPI_PACKET_CNT_EN, ®s->pkt_cnt); + + while (in_bytes) { + uint32_t spi_sts; + int temp; + + spi_sts = readl(®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; + writel(temp, ®s->tx_data); + out_bytes -= 4; + tx_lvl += 4; + } + while (rx_lvl >= 4 && in_bytes) { + temp = readl(®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 */ + writel(4 | SPI_PACKET_CNT_EN, ®s->pkt_cnt); + /* set FB_CLK_SEL */ + writel(SPI_FB_DELAY_180, ®s->fb_clk); + /* set CH_WIDTH and BUS_WIDTH as word */ + setbits_le32(®s->mode_cfg, + SPI_MODE_CH_WIDTH_WORD | SPI_MODE_BUS_WIDTH_WORD); + clrbits_le32(®s->ch_cfg, SPI_CH_CPOL_L); /* CPOL: active high */ + + /* clear rx and tx channel if set previously */ + clrbits_le32(®s->ch_cfg, SPI_RX_CH_ON | SPI_TX_CH_ON); + + setbits_le32(®s->swap_cfg, + SPI_RX_SWAP_EN | SPI_RX_BYTE_SWAP | SPI_RX_HWORD_SWAP); + + /* do a soft reset */ + setbits_le32(®s->ch_cfg, SPI_CH_RST); + clrbits_le32(®s->ch_cfg, SPI_CH_RST); + + /* now set rx and tx channel ON */ + setbits_le32(®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; + clrbits_le32(®s->cs_reg, SPI_SLAVE_SIG_INACT); /* CS low */ + + /* Send read instruction (0x3h) followed by a 24 bit addr */ + writel((SF_READ_DATA_CMD << 24) | off, ®s->tx_data); + + /* waiting for TX done */ + while (!(readl(®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); + } + + setbits_le32(®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 + */ + clrbits_le32(®s->mode_cfg, + SPI_MODE_CH_WIDTH_WORD | SPI_MODE_BUS_WIDTH_WORD); + writel(0, ®s->swap_cfg); + + /* + * Flush spi tx, rx fifos and reset the SPI controller + * and clear rx/tx channel + */ + clrsetbits_le32(®s->ch_cfg, SPI_CH_HS_EN, SPI_CH_RST); + clrbits_le32(®s->ch_cfg, SPI_CH_RST); + clrbits_le32(®s->ch_cfg, SPI_TX_CH_ON | SPI_RX_CH_ON); + return 0; +} + +// SPI as CBFS media. +struct exynos_spi_media { + struct exynos_spi *regs; + struct cbfs_simple_buffer buffer; +}; + +static int exynos_spi_cbfs_open(struct cbfs_media *media) { + struct exynos_spi_media *spi = (struct exynos_spi_media*)media->context; + DEBUG_SPI("exynos_spi_cbfs_open\n"); + return exynos_spi_open(spi->regs); +} + +static int exynos_spi_cbfs_close(struct cbfs_media *media) { + struct exynos_spi_media *spi = (struct exynos_spi_media*)media->context; + DEBUG_SPI("exynos_spi_cbfs_close\n"); + return exynos_spi_close(spi->regs); +} + +static size_t exynos_spi_cbfs_read(struct cbfs_media *media, void *dest, + size_t offset, size_t count) { + struct exynos_spi_media *spi = (struct exynos_spi_media*)media->context; + int bytes; + DEBUG_SPI("exynos_spi_cbfs_read(%u)\n", count); + bytes = exynos_spi_read(spi->regs, dest, count, offset); + // Flush and re-open the device. + exynos_spi_close(spi->regs); + exynos_spi_open(spi->regs); + return bytes; +} + +static void *exynos_spi_cbfs_map(struct cbfs_media *media, size_t offset, + size_t count) { + struct exynos_spi_media *spi = (struct exynos_spi_media*)media->context; + DEBUG_SPI("exynos_spi_cbfs_map\n"); + // See exynos_spi_rx_tx for I/O alignment limitation. + if (count % 4) + count += 4 - (count % 4); + return cbfs_simple_buffer_map(&spi->buffer, media, offset, count); +} + +static void *exynos_spi_cbfs_unmap(struct cbfs_media *media, + const void *address) { + struct exynos_spi_media *spi = (struct exynos_spi_media*)media->context; + DEBUG_SPI("exynos_spi_cbfs_unmap\n"); + return cbfs_simple_buffer_unmap(&spi->buffer, address); +} + +int initialize_exynos_spi_cbfs_media(struct cbfs_media *media, + void *buffer_address, + size_t buffer_size) { + // TODO Replace static variable to support multiple streams. + static struct exynos_spi_media context; + DEBUG_SPI("initialize_exynos_spi_cbfs_media\n"); + + context.regs = (void*)EXYNOS5_SPI1_BASE; + context.buffer.allocated = context.buffer.last_allocate = 0; + context.buffer.buffer = buffer_address; + context.buffer.size = buffer_size; + media->context = (void*)&context; + media->open = exynos_spi_cbfs_open; + media->close = exynos_spi_cbfs_close; + media->read = exynos_spi_cbfs_read; + media->map = exynos_spi_cbfs_map; + media->unmap = exynos_spi_cbfs_unmap; + + return 0; +} |