summaryrefslogtreecommitdiffstats
path: root/drivers/spi
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/Kconfig9
-rw-r--r--drivers/spi/Makefile1
-rw-r--r--drivers/spi/spi-falcon.c469
3 files changed, 479 insertions, 0 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 4cde4fb0cd6..5f84b5563c2 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -144,6 +144,15 @@ config SPI_EP93XX
This enables using the Cirrus EP93xx SPI controller in master
mode.
+config SPI_FALCON
+ tristate "Falcon SPI controller support"
+ depends on SOC_FALCON
+ help
+ The external bus unit (EBU) found on the FALC-ON SoC has SPI
+ emulation that is designed for serial flash access. This driver
+ has only been tested with m25p80 type chips. The hardware has no
+ support for other types of SPI peripherals.
+
config SPI_GPIO
tristate "GPIO-based bitbanging SPI Master"
depends on GENERIC_GPIO
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 273f50d1127..3920dcf4c74 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_SPI_DW_MMIO) += spi-dw-mmio.o
obj-$(CONFIG_SPI_DW_PCI) += spi-dw-midpci.o
spi-dw-midpci-objs := spi-dw-pci.o spi-dw-mid.o
obj-$(CONFIG_SPI_EP93XX) += spi-ep93xx.o
+obj-$(CONFIG_SPI_FALCON) += spi-falcon.o
obj-$(CONFIG_SPI_FSL_LIB) += spi-fsl-lib.o
obj-$(CONFIG_SPI_FSL_ESPI) += spi-fsl-espi.o
obj-$(CONFIG_SPI_FSL_SPI) += spi-fsl-spi.o
diff --git a/drivers/spi/spi-falcon.c b/drivers/spi/spi-falcon.c
new file mode 100644
index 00000000000..8f6aa735a24
--- /dev/null
+++ b/drivers/spi/spi-falcon.c
@@ -0,0 +1,469 @@
+/*
+ * 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/workqueue.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;
+
+ if (spi->chip_select > 0)
+ return -ENODEV;
+
+ 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_prepare_xfer(struct spi_master *master)
+{
+ return 0;
+}
+
+static int falcon_sflash_unprepare_xfer(struct spi_master *master)
+{
+ 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;
+ m->complete(m->context);
+
+ return 0;
+}
+
+static int __devinit falcon_sflash_probe(struct platform_device *pdev)
+{
+ struct falcon_sflash *priv;
+ struct spi_master *master;
+ int ret;
+
+ if (ltq_boot_select() != BS_SPI) {
+ dev_err(&pdev->dev, "invalid bootstrap options\n");
+ return -ENODEV;
+ }
+
+ 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->num_chipselect = 1;
+ master->bus_num = -1;
+ master->setup = falcon_sflash_setup;
+ master->prepare_transfer_hardware = falcon_sflash_prepare_xfer;
+ master->transfer_one_message = falcon_sflash_xfer_one;
+ master->unprepare_transfer_hardware = falcon_sflash_unprepare_xfer;
+ master->dev.of_node = pdev->dev.of_node;
+
+ platform_set_drvdata(pdev, priv);
+
+ ret = spi_register_master(master);
+ if (ret)
+ spi_master_put(master);
+ return ret;
+}
+
+static int __devexit falcon_sflash_remove(struct platform_device *pdev)
+{
+ struct falcon_sflash *priv = platform_get_drvdata(pdev);
+
+ spi_unregister_master(priv->master);
+
+ return 0;
+}
+
+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,
+ .remove = __devexit_p(falcon_sflash_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = falcon_sflash_match,
+ }
+};
+
+module_platform_driver(falcon_sflash_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Lantiq Falcon SPI/SFLASH controller driver");
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-25 16:07:29 +0000