--- /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 / svn-archive / archive.git / blobdiff