/* SPDX-License-Identifier: GPL-2.0-only */ #include <device/mmio.h> #include <assert.h> #include <console/console.h> #include <soc/cpu.h> #include <soc/spi.h> #include <spi-generic.h> #include <stddef.h> #include <stdint.h> #include <string.h> #include <symbols.h> #define EXYNOS_SPI_MAX_TRANSFER_BYTES (65535) #if defined(CONFIG_DEBUG_SPI) && CONFIG_DEBUG_SPI # define DEBUG_SPI(x,...) printk(BIOS_DEBUG, "EXYNOS_SPI: " x) #else # define DEBUG_SPI(x,...) #endif struct exynos_spi_slave { struct spi_slave slave; struct exynos_spi *regs; int initialized; }; /* TODO(hungte) Move the SPI param list to per-board configuration, probably * Kconfig or mainboard.c */ static struct exynos_spi_slave exynos_spi_slaves[3] = { // SPI 0 { .slave = { .bus = 0, }, .regs = (void *)EXYNOS5_SPI0_BASE, }, // SPI 1 { .slave = { .bus = 1, }, .regs = (void *)EXYNOS5_SPI1_BASE, }, // SPI 2 { .slave = { .bus = 2, }, .regs = (void *)EXYNOS5_SPI2_BASE, }, }; static inline struct exynos_spi_slave *to_exynos_spi(const struct spi_slave *slave) { return &exynos_spi_slaves[slave->bus]; } static void spi_sw_reset(struct exynos_spi *regs, int word) { const uint32_t orig_mode_cfg = read32(®s->mode_cfg); uint32_t mode_cfg = orig_mode_cfg; const uint32_t orig_swap_cfg = read32(®s->swap_cfg); uint32_t swap_cfg = orig_swap_cfg; mode_cfg &= ~(SPI_MODE_CH_WIDTH_MASK | SPI_MODE_BUS_WIDTH_MASK); if (word) { mode_cfg |= SPI_MODE_CH_WIDTH_WORD | SPI_MODE_BUS_WIDTH_WORD; swap_cfg |= SPI_RX_SWAP_EN | SPI_RX_BYTE_SWAP | SPI_RX_HWORD_SWAP | SPI_TX_SWAP_EN | SPI_TX_BYTE_SWAP | SPI_TX_HWORD_SWAP; } else { mode_cfg |= SPI_MODE_CH_WIDTH_BYTE | SPI_MODE_BUS_WIDTH_BYTE; swap_cfg = 0; } if (mode_cfg != orig_mode_cfg) write32(®s->mode_cfg, mode_cfg); if (swap_cfg != orig_swap_cfg) write32(®s->swap_cfg, swap_cfg); clrbits32(®s->ch_cfg, SPI_RX_CH_ON | SPI_TX_CH_ON); setbits32(®s->ch_cfg, SPI_CH_RST); clrbits32(®s->ch_cfg, SPI_CH_RST); setbits32(®s->ch_cfg, SPI_RX_CH_ON | SPI_TX_CH_ON); } static void exynos_spi_init(struct exynos_spi *regs) { // Set FB_CLK_SEL. write32(®s->fb_clk, SPI_FB_DELAY_180); // CPOL: Active high. clrbits32(®s->ch_cfg, SPI_CH_CPOL_L); // 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); clrbits32(®s->ch_cfg, SPI_CH_HS_EN); // Do a soft reset, which will also enable both channels. spi_sw_reset(regs, 1); } static int spi_ctrlr_claim_bus(const struct spi_slave *slave) { struct exynos_spi *regs = to_exynos_spi(slave)->regs; // TODO(hungte) Add some delay if too many transactions happen at once. clrbits32(®s->cs_reg, SPI_SLAVE_SIG_INACT); return 0; } static void spi_transfer(struct exynos_spi *regs, void *in, const void *out, size_t size) { u8 *inb = in; const u8 *outb = out; size_t width = (size % 4) ? 1 : 4; while (size) { size_t packets = size / width; // The packet count field is 16 bits wide. packets = MIN(packets, (1 << 16) - 1); size_t out_bytes, in_bytes; out_bytes = in_bytes = packets * width; spi_sw_reset(regs, width == 4); write32(®s->pkt_cnt, packets | SPI_PACKET_CNT_EN); while (out_bytes || in_bytes) { uint32_t spi_sts = read32(®s->spi_sts); int rx_lvl = ((spi_sts >> 15) & 0x1ff); int tx_lvl = ((spi_sts >> 6) & 0x1ff); if (tx_lvl < 32 && tx_lvl < out_bytes) { uint32_t data = 0xffffffff; if (outb) { memcpy(&data, outb, width); outb += width; } write32(®s->tx_data, data); out_bytes -= width; } if (rx_lvl >= width) { uint32_t data = read32(®s->rx_data); if (inb) { memcpy(inb, &data, width); inb += width; } in_bytes -= width; } } size -= packets * width; } } static int spi_ctrlr_xfer(const struct spi_slave *slave, const void *dout, size_t bytes_out, void *din, size_t bytes_in) { struct exynos_spi *regs = to_exynos_spi(slave)->regs; if (bytes_out && bytes_in) { size_t min_size = MIN(bytes_out, bytes_in); spi_transfer(regs, din, dout, min_size); bytes_out -= min_size; bytes_in -= min_size; din = (uint8_t *)din + min_size; dout = (const uint8_t *)dout + min_size; } if (bytes_in) spi_transfer(regs, din, NULL, bytes_in); else if (bytes_out) spi_transfer(regs, NULL, dout, bytes_out); return 0; } static void spi_ctrlr_release_bus(const struct spi_slave *slave) { struct exynos_spi *regs = to_exynos_spi(slave)->regs; setbits32(®s->cs_reg, SPI_SLAVE_SIG_INACT); } static int spi_ctrlr_setup(const struct spi_slave *slave) { ASSERT(slave->bus < 3); struct exynos_spi_slave *eslave; eslave = to_exynos_spi(slave); if (!eslave->initialized) { exynos_spi_init(eslave->regs); eslave->initialized = 1; } return 0; } static const struct spi_ctrlr spi_ctrlr = { .setup = spi_ctrlr_setup, .claim_bus = spi_ctrlr_claim_bus, .release_bus = spi_ctrlr_release_bus, .xfer = spi_ctrlr_xfer, .max_xfer_size = SPI_CTRLR_DEFAULT_MAX_XFER_SIZE, }; const struct spi_ctrlr_buses spi_ctrlr_bus_map[] = { { .ctrlr = &spi_ctrlr, .bus_start = 0, .bus_end = 2, }, }; const size_t spi_ctrlr_bus_map_count = ARRAY_SIZE(spi_ctrlr_bus_map); static int exynos_spi_read(struct spi_slave *slave, void *dest, uint32_t len, uint32_t off) { struct exynos_spi *regs = to_exynos_spi(slave)->regs; u32 command; spi_claim_bus(slave); // Send address. ASSERT(off < (1 << 24)); command = htonl(SF_READ_DATA_CMD << 24 | off); spi_transfer(regs, NULL, &command, sizeof(command)); // Read the data. spi_transfer(regs, dest, NULL, len); spi_release_bus(slave); return len; } static struct exynos_spi_slave *boot_slave; static ssize_t exynos_spi_readat(const struct region_device *rdev, void *dest, size_t offset, size_t count) { DEBUG_SPI("exynos_spi_cbfs_read(%u)\n", count); return exynos_spi_read(&boot_slave->slave, dest, count, offset); } 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 = &exynos_spi_slaves[1]; mmap_helper_device_init(&mdev, _cbfs_cache, REGION_SIZE(cbfs_cache)); } const struct region_device *exynos_spi_boot_device(void) { return &mdev.rdev; }