/* * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * * Copyright (C) 2012 Thomas Langer <thomas.langer@lantiq.com> */ #include <linux/module.h> #include <linux/device.h> #include <linux/platform_device.h> #include <linux/spi/spi.h> #include <linux/delay.h> #include <linux/of.h> #include <linux/of_platform.h> #include <lantiq_soc.h> #define DRV_NAME "sflash-falcon" #define FALCON_SPI_XFER_BEGIN (1 << 0) #define FALCON_SPI_XFER_END (1 << 1) /* Bus Read Configuration Register0 */ #define BUSRCON0 0x00000010 /* Bus Write Configuration Register0 */ #define BUSWCON0 0x00000018 /* Serial Flash Configuration Register */ #define SFCON 0x00000080 /* Serial Flash Time Register */ #define SFTIME 0x00000084 /* Serial Flash Status Register */ #define SFSTAT 0x00000088 /* Serial Flash Command Register */ #define SFCMD 0x0000008C /* Serial Flash Address Register */ #define SFADDR 0x00000090 /* Serial Flash Data Register */ #define SFDATA 0x00000094 /* Serial Flash I/O Control Register */ #define SFIO 0x00000098 /* EBU Clock Control Register */ #define EBUCC 0x000000C4 /* Dummy Phase Length */ #define SFCMD_DUMLEN_OFFSET 16 #define SFCMD_DUMLEN_MASK 0x000F0000 /* Chip Select */ #define SFCMD_CS_OFFSET 24 #define SFCMD_CS_MASK 0x07000000 /* field offset */ #define SFCMD_ALEN_OFFSET 20 #define SFCMD_ALEN_MASK 0x00700000 /* SCK Rise-edge Position */ #define SFTIME_SCKR_POS_OFFSET 8 #define SFTIME_SCKR_POS_MASK 0x00000F00 /* SCK Period */ #define SFTIME_SCK_PER_OFFSET 0 #define SFTIME_SCK_PER_MASK 0x0000000F /* SCK Fall-edge Position */ #define SFTIME_SCKF_POS_OFFSET 12 #define SFTIME_SCKF_POS_MASK 0x0000F000 /* Device Size */ #define SFCON_DEV_SIZE_A23_0 0x03000000 #define SFCON_DEV_SIZE_MASK 0x0F000000 /* Read Data Position */ #define SFTIME_RD_POS_MASK 0x000F0000 /* Data Output */ #define SFIO_UNUSED_WD_MASK 0x0000000F /* Command Opcode mask */ #define SFCMD_OPC_MASK 0x000000FF /* dlen bytes of data to write */ #define SFCMD_DIR_WRITE 0x00000100 /* Data Length offset */ #define SFCMD_DLEN_OFFSET 9 /* Command Error */ #define SFSTAT_CMD_ERR 0x20000000 /* Access Command Pending */ #define SFSTAT_CMD_PEND 0x00400000 /* Frequency set to 100MHz. */ #define EBUCC_EBUDIV_SELF100 0x00000001 /* Serial Flash */ #define BUSRCON0_AGEN_SERIAL_FLASH 0xF0000000 /* 8-bit multiplexed */ #define BUSRCON0_PORTW_8_BIT_MUX 0x00000000 /* Serial Flash */ #define BUSWCON0_AGEN_SERIAL_FLASH 0xF0000000 /* Chip Select after opcode */ #define SFCMD_KEEP_CS_KEEP_SELECTED 0x00008000 #define CLOCK_100M 100000000 #define CLOCK_50M 50000000 struct falcon_sflash { u32 sfcmd; /* for caching of opcode, direction, ... */ struct spi_master *master; }; int falcon_sflash_xfer(struct spi_device *spi, struct spi_transfer *t, unsigned long flags) { struct device *dev = &spi->dev; struct falcon_sflash *priv = spi_master_get_devdata(spi->master); const u8 *txp = t->tx_buf; u8 *rxp = t->rx_buf; unsigned int bytelen = ((8 * t->len + 7) / 8); unsigned int len, alen, dumlen; u32 val; enum { state_init, state_command_prepare, state_write, state_read, state_disable_cs, state_end } state = state_init; do { switch (state) { case state_init: /* detect phase of upper layer sequence */ { /* initial write ? */ if (flags & FALCON_SPI_XFER_BEGIN) { if (!txp) { dev_err(dev, "BEGIN without tx data!\n"); return -ENODATA; } /* * Prepare the parts of the sfcmd register, * which should not change during a sequence! * Only exception are the length fields, * especially alen and dumlen. */ priv->sfcmd = ((spi->chip_select << SFCMD_CS_OFFSET) & SFCMD_CS_MASK); priv->sfcmd |= SFCMD_KEEP_CS_KEEP_SELECTED; priv->sfcmd |= *txp; txp++; bytelen--; if (bytelen) { /* * more data: * maybe address and/or dummy */ state = state_command_prepare; break; } else { dev_dbg(dev, "write cmd %02X\n", priv->sfcmd & SFCMD_OPC_MASK); } } /* continued write ? */ if (txp && bytelen) { state = state_write; break; } /* read data? */ if (rxp && bytelen) { state = state_read; break; } /* end of sequence? */ if (flags & FALCON_SPI_XFER_END) state = state_disable_cs; else state = state_end; break; } /* collect tx data for address and dummy phase */ case state_command_prepare: { /* txp is valid, already checked */ val = 0; alen = 0; dumlen = 0; while (bytelen > 0) { if (alen < 3) { val = (val << 8) | (*txp++); alen++; } else if ((dumlen < 15) && (*txp == 0)) { /* * assume dummy bytes are set to 0 * from upper layer */ dumlen++; txp++; } else { break; } bytelen--; } priv->sfcmd &= ~(SFCMD_ALEN_MASK | SFCMD_DUMLEN_MASK); priv->sfcmd |= (alen << SFCMD_ALEN_OFFSET) | (dumlen << SFCMD_DUMLEN_OFFSET); if (alen > 0) ltq_ebu_w32(val, SFADDR); dev_dbg(dev, "wr %02X, alen=%d (addr=%06X) dlen=%d\n", priv->sfcmd & SFCMD_OPC_MASK, alen, val, dumlen); if (bytelen > 0) { /* continue with write */ state = state_write; } else if (flags & FALCON_SPI_XFER_END) { /* end of sequence? */ state = state_disable_cs; } else { /* * go to end and expect another * call (read or write) */ state = state_end; } break; } case state_write: { /* txp still valid */ priv->sfcmd |= SFCMD_DIR_WRITE; len = 0; val = 0; do { if (bytelen--) val |= (*txp++) << (8 * len++); if ((flags & FALCON_SPI_XFER_END) && (bytelen == 0)) { priv->sfcmd &= ~SFCMD_KEEP_CS_KEEP_SELECTED; } if ((len == 4) || (bytelen == 0)) { ltq_ebu_w32(val, SFDATA); ltq_ebu_w32(priv->sfcmd | (len<<SFCMD_DLEN_OFFSET), SFCMD); len = 0; val = 0; priv->sfcmd &= ~(SFCMD_ALEN_MASK | SFCMD_DUMLEN_MASK); } } while (bytelen); state = state_end; break; } case state_read: { /* read data */ priv->sfcmd &= ~SFCMD_DIR_WRITE; do { if ((flags & FALCON_SPI_XFER_END) && (bytelen <= 4)) { priv->sfcmd &= ~SFCMD_KEEP_CS_KEEP_SELECTED; } len = (bytelen > 4) ? 4 : bytelen; bytelen -= len; ltq_ebu_w32(priv->sfcmd | (len << SFCMD_DLEN_OFFSET), SFCMD); priv->sfcmd &= ~(SFCMD_ALEN_MASK | SFCMD_DUMLEN_MASK); do { val = ltq_ebu_r32(SFSTAT); if (val & SFSTAT_CMD_ERR) { /* reset error status */ dev_err(dev, "SFSTAT: CMD_ERR"); dev_err(dev, " (%x)\n", val); ltq_ebu_w32(SFSTAT_CMD_ERR, SFSTAT); return -EBADE; } } while (val & SFSTAT_CMD_PEND); val = ltq_ebu_r32(SFDATA); do { *rxp = (val & 0xFF); rxp++; val >>= 8; len--; } while (len); } while (bytelen); state = state_end; break; } case state_disable_cs: { priv->sfcmd &= ~SFCMD_KEEP_CS_KEEP_SELECTED; ltq_ebu_w32(priv->sfcmd | (0 << SFCMD_DLEN_OFFSET), SFCMD); val = ltq_ebu_r32(SFSTAT); if (val & SFSTAT_CMD_ERR) { /* reset error status */ dev_err(dev, "SFSTAT: CMD_ERR (%x)\n", val); ltq_ebu_w32(SFSTAT_CMD_ERR, SFSTAT); return -EBADE; } state = state_end; break; } case state_end: break; } } while (state != state_end); return 0; } static int falcon_sflash_setup(struct spi_device *spi) { unsigned int i; unsigned long flags; spin_lock_irqsave(&ebu_lock, flags); if (spi->max_speed_hz >= CLOCK_100M) { /* set EBU clock to 100 MHz */ ltq_sys1_w32_mask(0, EBUCC_EBUDIV_SELF100, EBUCC); i = 1; /* divider */ } else { /* set EBU clock to 50 MHz */ ltq_sys1_w32_mask(EBUCC_EBUDIV_SELF100, 0, EBUCC); /* search for suitable divider */ for (i = 1; i < 7; i++) { if (CLOCK_50M / i <= spi->max_speed_hz) break; } } /* setup period of serial clock */ ltq_ebu_w32_mask(SFTIME_SCKF_POS_MASK | SFTIME_SCKR_POS_MASK | SFTIME_SCK_PER_MASK, (i << SFTIME_SCKR_POS_OFFSET) | (i << (SFTIME_SCK_PER_OFFSET + 1)), SFTIME); /* * set some bits of unused_wd, to not trigger HOLD/WP * signals on non QUAD flashes */ ltq_ebu_w32((SFIO_UNUSED_WD_MASK & (0x8 | 0x4)), SFIO); ltq_ebu_w32(BUSRCON0_AGEN_SERIAL_FLASH | BUSRCON0_PORTW_8_BIT_MUX, BUSRCON0); ltq_ebu_w32(BUSWCON0_AGEN_SERIAL_FLASH, BUSWCON0); /* set address wrap around to maximum for 24-bit addresses */ ltq_ebu_w32_mask(SFCON_DEV_SIZE_MASK, SFCON_DEV_SIZE_A23_0, SFCON); spin_unlock_irqrestore(&ebu_lock, flags); return 0; } static int falcon_sflash_xfer_one(struct spi_master *master, struct spi_message *m) { struct falcon_sflash *priv = spi_master_get_devdata(master); struct spi_transfer *t; unsigned long spi_flags; unsigned long flags; int ret = 0; priv->sfcmd = 0; m->actual_length = 0; spi_flags = FALCON_SPI_XFER_BEGIN; list_for_each_entry(t, &m->transfers, transfer_list) { if (list_is_last(&t->transfer_list, &m->transfers)) spi_flags |= FALCON_SPI_XFER_END; spin_lock_irqsave(&ebu_lock, flags); ret = falcon_sflash_xfer(m->spi, t, spi_flags); spin_unlock_irqrestore(&ebu_lock, flags); if (ret) break; m->actual_length += t->len; WARN_ON(t->delay_usecs || t->cs_change); spi_flags = 0; } m->status = ret; spi_finalize_current_message(master); return 0; } static int falcon_sflash_probe(struct platform_device *pdev) { struct falcon_sflash *priv; struct spi_master *master; int ret; master = spi_alloc_master(&pdev->dev, sizeof(*priv)); if (!master) return -ENOMEM; priv = spi_master_get_devdata(master); priv->master = master; master->mode_bits = SPI_MODE_3; master->flags = SPI_MASTER_HALF_DUPLEX; master->setup = falcon_sflash_setup; master->transfer_one_message = falcon_sflash_xfer_one; master->dev.of_node = pdev->dev.of_node; ret = devm_spi_register_master(&pdev->dev, master); if (ret) spi_master_put(master); return ret; } static const struct of_device_id falcon_sflash_match[] = { { .compatible = "lantiq,sflash-falcon" }, {}, }; MODULE_DEVICE_TABLE(of, falcon_sflash_match); static struct platform_driver falcon_sflash_driver = { .probe = falcon_sflash_probe, .driver = { .name = DRV_NAME, .of_match_table = falcon_sflash_match, } }; module_platform_driver(falcon_sflash_driver); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Lantiq Falcon SPI/SFLASH controller driver");