+++ /dev/null
-/*
- * 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) 2010 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/workqueue.h>
-
-#include <lantiq_soc.h>
-
-#define DRV_NAME "falcon_spi"
-
-#define FALCON_SPI_XFER_BEGIN (1 << 0)
-#define FALCON_SPI_XFER_END (1 << 1)
-
-/* Bus Read Configuration Register0 */
-#define LTQ_BUSRCON0 0x00000010
-/* Bus Write Configuration Register0 */
-#define LTQ_BUSWCON0 0x00000018
-/* Serial Flash Configuration Register */
-#define LTQ_SFCON 0x00000080
-/* Serial Flash Time Register */
-#define LTQ_SFTIME 0x00000084
-/* Serial Flash Status Register */
-#define LTQ_SFSTAT 0x00000088
-/* Serial Flash Command Register */
-#define LTQ_SFCMD 0x0000008C
-/* Serial Flash Address Register */
-#define LTQ_SFADDR 0x00000090
-/* Serial Flash Data Register */
-#define LTQ_SFDATA 0x00000094
-/* Serial Flash I/O Control Register */
-#define LTQ_SFIO 0x00000098
-/* EBU Clock Control Register */
-#define LTQ_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
-
-struct falcon_spi {
- u32 sfcmd; /* for caching of opcode, direction, ... */
- struct spi_master *master;
-};
-
-int
-falcon_spi_xfer(struct spi_device *spi,
- struct spi_transfer *t,
- unsigned long flags)
-{
- struct device *dev = &spi->dev;
- struct falcon_spi *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 -1;
- }
- /*
- * 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, LTQ_SFADDR);
-
- dev_dbg(dev, "write cmd %02X, alen=%d "
- "(addr=%06X) dumlen=%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, LTQ_SFDATA);
- ltq_ebu_w32(priv->sfcmd
- | (len<<SFCMD_DLEN_OFFSET),
- LTQ_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), LTQ_SFCMD);
- priv->sfcmd &= ~(SFCMD_ALEN_MASK
- | SFCMD_DUMLEN_MASK);
- do {
- val = ltq_ebu_r32(LTQ_SFSTAT);
- if (val & SFSTAT_CMD_ERR) {
- /* reset error status */
- dev_err(dev, "SFSTAT: CMD_ERR "
- "(%x)\n", val);
- ltq_ebu_w32(SFSTAT_CMD_ERR,
- LTQ_SFSTAT);
- return -1;
- }
- } while (val & SFSTAT_CMD_PEND);
- val = ltq_ebu_r32(LTQ_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),
- LTQ_SFCMD);
- val = ltq_ebu_r32(LTQ_SFSTAT);
- if (val & SFSTAT_CMD_ERR) {
- /* reset error status */
- dev_err(dev, "SFSTAT: CMD_ERR (%x)\n", val);
- ltq_ebu_w32(SFSTAT_CMD_ERR, LTQ_SFSTAT);
- return -1;
- }
- state = state_end;
- break;
- }
- case state_end:
- break;
- }
- } while (state != state_end);
-
- return 0;
-}
-
-static int
-falcon_spi_setup(struct spi_device *spi)
-{
- struct device *dev = &spi->dev;
- const u32 ebuclk = 100000000;
- unsigned int i;
- unsigned long flags;
-
- dev_dbg(dev, "setup\n");
-
- if (spi->master->bus_num > 0 || spi->chip_select > 0)
- return -ENODEV;
-
- spin_lock_irqsave(&ebu_lock, flags);
-
- if (ebuclk < spi->max_speed_hz) {
- /* set EBU clock to 100 MHz */
- ltq_sys1_w32_mask(0, EBUCC_EBUDIV_SELF100, LTQ_EBUCC);
- i = 1; /* divider */
- } else {
- /* set EBU clock to 50 MHz */
- ltq_sys1_w32_mask(EBUCC_EBUDIV_SELF100, 0, LTQ_EBUCC);
-
- /* search for suitable divider */
- for (i = 1; i < 7; i++) {
- if (ebuclk / 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)),
- LTQ_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)), LTQ_SFIO);
-
- ltq_ebu_w32(BUSRCON0_AGEN_SERIAL_FLASH | BUSRCON0_PORTW_8_BIT_MUX,
- LTQ_BUSRCON0);
- ltq_ebu_w32(BUSWCON0_AGEN_SERIAL_FLASH, LTQ_BUSWCON0);
- /* set address wrap around to maximum for 24-bit addresses */
- ltq_ebu_w32_mask(SFCON_DEV_SIZE_MASK, SFCON_DEV_SIZE_A23_0, LTQ_SFCON);
-
- spin_unlock_irqrestore(&ebu_lock, flags);
-
- return 0;
-}
-
-static int
-falcon_spi_transfer(struct spi_device *spi, struct spi_message *m)
-{
- struct falcon_spi *priv = spi_master_get_devdata(spi->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_spi_xfer(spi, t, spi_flags);
- spin_unlock_irqrestore(&ebu_lock, flags);
-
- if (ret)
- break;
-
- m->actual_length += t->len;
-
- if (t->delay_usecs || t->cs_change)
- BUG();
-
- spi_flags = 0;
- }
-
- m->status = ret;
- m->complete(m->context);
-
- return 0;
-}
-
-static void
-falcon_spi_cleanup(struct spi_device *spi)
-{
- struct device *dev = &spi->dev;
-
- dev_dbg(dev, "cleanup\n");
-}
-
-static int __devinit
-falcon_spi_probe(struct platform_device *pdev)
-{
- struct device *dev = &pdev->dev;
- struct falcon_spi *priv;
- struct spi_master *master;
- int ret;
-
- dev_dbg(dev, "probing\n");
-
- master = spi_alloc_master(&pdev->dev, sizeof(*priv));
- if (!master) {
- dev_err(dev, "no memory for spi_master\n");
- return -ENOMEM;
- }
-
- priv = spi_master_get_devdata(master);
- priv->master = master;
-
- master->mode_bits = SPI_MODE_3;
- master->num_chipselect = 1;
- master->bus_num = 0;
-
- master->setup = falcon_spi_setup;
- master->transfer = falcon_spi_transfer;
- master->cleanup = falcon_spi_cleanup;
-
- platform_set_drvdata(pdev, priv);
-
- ret = spi_register_master(master);
- if (ret)
- spi_master_put(master);
-
- return ret;
-}
-
-static int __devexit
-falcon_spi_remove(struct platform_device *pdev)
-{
- struct device *dev = &pdev->dev;
- struct falcon_spi *priv = platform_get_drvdata(pdev);
-
- dev_dbg(dev, "removed\n");
-
- spi_unregister_master(priv->master);
-
- return 0;
-}
-
-static struct platform_driver falcon_spi_driver = {
- .probe = falcon_spi_probe,
- .remove = __devexit_p(falcon_spi_remove),
- .driver = {
- .name = DRV_NAME,
- .owner = THIS_MODULE
- }
-};
-
-static int __init
-falcon_spi_init(void)
-{
- return platform_driver_register(&falcon_spi_driver);
-}
-
-static void __exit
-falcon_spi_exit(void)
-{
- platform_driver_unregister(&falcon_spi_driver);
-}
-
-module_init(falcon_spi_init);
-module_exit(falcon_spi_exit);
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Lantiq Falcon SPI controller driver");
projects / openwrt.git / blobdiff