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path: root/drivers/spi/omap3_spi.c
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Diffstat (limited to 'drivers/spi/omap3_spi.c')
-rw-r--r--drivers/spi/omap3_spi.c352
1 files changed, 352 insertions, 0 deletions
diff --git a/drivers/spi/omap3_spi.c b/drivers/spi/omap3_spi.c
new file mode 100644
index 0000000..af12c0e
--- /dev/null
+++ b/drivers/spi/omap3_spi.c
@@ -0,0 +1,352 @@
+/*
+ * Copyright (C) 2010 Dirk Behme <dirk.behme@googlemail.com>
+ *
+ * Driver for McSPI controller on OMAP3. Based on davinci_spi.c
+ * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * Parts taken from linux/drivers/spi/omap2_mcspi.c
+ * Copyright (C) 2005, 2006 Nokia Corporation
+ *
+ * Modified by Ruslan Araslanov <ruslan.araslanov@vitecmm.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+#include <common.h>
+#include <spi.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include "omap3_spi.h"
+
+#define WORD_LEN 8
+#define SPI_WAIT_TIMEOUT 3000000;
+
+static void spi_reset(struct omap3_spi_slave *ds)
+{
+ unsigned int tmp;
+
+ writel(OMAP3_MCSPI_SYSCONFIG_SOFTRESET, &ds->regs->sysconfig);
+ do {
+ tmp = readl(&ds->regs->sysstatus);
+ } while (!(tmp & OMAP3_MCSPI_SYSSTATUS_RESETDONE));
+
+ writel(OMAP3_MCSPI_SYSCONFIG_AUTOIDLE |
+ OMAP3_MCSPI_SYSCONFIG_ENAWAKEUP |
+ OMAP3_MCSPI_SYSCONFIG_SMARTIDLE,
+ &ds->regs->sysconfig);
+
+ writel(OMAP3_MCSPI_WAKEUPENABLE_WKEN, &ds->regs->wakeupenable);
+}
+
+void spi_init()
+{
+ /* do nothing */
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct omap3_spi_slave *ds;
+
+ ds = malloc(sizeof(struct omap3_spi_slave));
+ if (!ds) {
+ printf("SPI error: malloc of SPI structure failed\n");
+ return NULL;
+ }
+
+ /*
+ * OMAP3 McSPI (MultiChannel SPI) has 4 busses (modules)
+ * with different number of chip selects (CS, channels):
+ * McSPI1 has 4 CS (bus 0, cs 0 - 3)
+ * McSPI2 has 2 CS (bus 1, cs 0 - 1)
+ * McSPI3 has 2 CS (bus 2, cs 0 - 1)
+ * McSPI4 has 1 CS (bus 3, cs 0)
+ */
+
+ switch (bus) {
+ case 0:
+ ds->regs = (struct mcspi *)OMAP3_MCSPI1_BASE;
+ break;
+ case 1:
+ ds->regs = (struct mcspi *)OMAP3_MCSPI2_BASE;
+ break;
+ case 2:
+ ds->regs = (struct mcspi *)OMAP3_MCSPI3_BASE;
+ break;
+ case 3:
+ ds->regs = (struct mcspi *)OMAP3_MCSPI4_BASE;
+ break;
+ default:
+ printf("SPI error: unsupported bus %i. \
+ Supported busses 0 - 3\n", bus);
+ return NULL;
+ }
+ ds->slave.bus = bus;
+
+ if (((bus == 0) && (cs > 3)) ||
+ ((bus == 1) && (cs > 1)) ||
+ ((bus == 2) && (cs > 1)) ||
+ ((bus == 3) && (cs > 0))) {
+ printf("SPI error: unsupported chip select %i \
+ on bus %i\n", cs, bus);
+ return NULL;
+ }
+ ds->slave.cs = cs;
+
+ if (max_hz > OMAP3_MCSPI_MAX_FREQ) {
+ printf("SPI error: unsupported frequency %i Hz. \
+ Max frequency is 48 Mhz\n", max_hz);
+ return NULL;
+ }
+ ds->freq = max_hz;
+
+ if (mode > SPI_MODE_3) {
+ printf("SPI error: unsupported SPI mode %i\n", mode);
+ return NULL;
+ }
+ ds->mode = mode;
+
+ return &ds->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ struct omap3_spi_slave *ds = to_omap3_spi(slave);
+
+ free(ds);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ struct omap3_spi_slave *ds = to_omap3_spi(slave);
+ unsigned int conf, div = 0;
+
+ /* McSPI global module configuration */
+
+ /*
+ * setup when switching from (reset default) slave mode
+ * to single-channel master mode
+ */
+ spi_reset(ds);
+ conf = readl(&ds->regs->modulctrl);
+ conf &= ~(OMAP3_MCSPI_MODULCTRL_STEST | OMAP3_MCSPI_MODULCTRL_MS);
+ conf |= OMAP3_MCSPI_MODULCTRL_SINGLE;
+ writel(conf, &ds->regs->modulctrl);
+
+ /* McSPI individual channel configuration */
+
+ /* Calculate clock divisor. Valid range: 0x0 - 0xC ( /1 - /4096 ) */
+ if (ds->freq) {
+ while (div <= 0xC && (OMAP3_MCSPI_MAX_FREQ / (1 << div))
+ > ds->freq)
+ div++;
+ } else
+ div = 0xC;
+
+ conf = readl(&ds->regs->channel[ds->slave.cs].chconf);
+
+ /* standard 4-wire master mode: SCK, MOSI/out, MISO/in, nCS
+ * REVISIT: this controller could support SPI_3WIRE mode.
+ */
+ conf &= ~(OMAP3_MCSPI_CHCONF_IS|OMAP3_MCSPI_CHCONF_DPE1);
+ conf |= OMAP3_MCSPI_CHCONF_DPE0;
+
+ /* wordlength */
+ conf &= ~OMAP3_MCSPI_CHCONF_WL_MASK;
+ conf |= (WORD_LEN - 1) << 7;
+
+ /* set chipselect polarity; manage with FORCE */
+ if (!(ds->mode & SPI_CS_HIGH))
+ conf |= OMAP3_MCSPI_CHCONF_EPOL; /* active-low; normal */
+ else
+ conf &= ~OMAP3_MCSPI_CHCONF_EPOL;
+
+ /* set clock divisor */
+ conf &= ~OMAP3_MCSPI_CHCONF_CLKD_MASK;
+ conf |= div << 2;
+
+ /* set SPI mode 0..3 */
+ if (ds->mode & SPI_CPOL)
+ conf |= OMAP3_MCSPI_CHCONF_POL;
+ else
+ conf &= ~OMAP3_MCSPI_CHCONF_POL;
+ if (ds->mode & SPI_CPHA)
+ conf |= OMAP3_MCSPI_CHCONF_PHA;
+ else
+ conf &= ~OMAP3_MCSPI_CHCONF_PHA;
+
+ /* Transmit & receive mode */
+ conf &= ~OMAP3_MCSPI_CHCONF_TRM_MASK;
+
+ writel(conf, &ds->regs->channel[ds->slave.cs].chconf);
+
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+ struct omap3_spi_slave *ds = to_omap3_spi(slave);
+
+ /* Reset the SPI hardware */
+ spi_reset(ds);
+}
+
+int omap3_spi_write(struct spi_slave *slave, unsigned int len, const u8 *txp,
+ unsigned long flags)
+{
+ struct omap3_spi_slave *ds = to_omap3_spi(slave);
+ int i;
+ int timeout = SPI_WAIT_TIMEOUT;
+ int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf);
+
+ if (flags & SPI_XFER_BEGIN)
+ writel(OMAP3_MCSPI_CHCTRL_EN,
+ &ds->regs->channel[ds->slave.cs].chctrl);
+
+ chconf &= ~OMAP3_MCSPI_CHCONF_TRM_MASK;
+ chconf |= OMAP3_MCSPI_CHCONF_TRM_TX_ONLY;
+ chconf |= OMAP3_MCSPI_CHCONF_FORCE;
+ writel(chconf, &ds->regs->channel[ds->slave.cs].chconf);
+
+ for (i = 0; i < len; i++) {
+ /* wait till TX register is empty (TXS == 1) */
+ while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
+ OMAP3_MCSPI_CHSTAT_TXS)) {
+ if (--timeout <= 0) {
+ printf("SPI TXS timed out, status=0x%08x\n",
+ readl(&ds->regs->channel[ds->slave.cs].chstat));
+ return -1;
+ }
+ }
+ /* Write the data */
+ writel(txp[i], &ds->regs->channel[ds->slave.cs].tx);
+ }
+
+ if (flags & SPI_XFER_END) {
+ /* wait to finish of transfer */
+ while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
+ OMAP3_MCSPI_CHSTAT_EOT));
+
+ chconf &= ~OMAP3_MCSPI_CHCONF_FORCE;
+ writel(chconf, &ds->regs->channel[ds->slave.cs].chconf);
+
+ writel(0, &ds->regs->channel[ds->slave.cs].chctrl);
+ }
+ return 0;
+}
+
+int omap3_spi_read(struct spi_slave *slave, unsigned int len, u8 *rxp,
+ unsigned long flags)
+{
+ struct omap3_spi_slave *ds = to_omap3_spi(slave);
+ int i;
+ int timeout = SPI_WAIT_TIMEOUT;
+ int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf);
+
+ if (flags & SPI_XFER_BEGIN)
+ writel(OMAP3_MCSPI_CHCTRL_EN,
+ &ds->regs->channel[ds->slave.cs].chctrl);
+
+ chconf &= ~OMAP3_MCSPI_CHCONF_TRM_MASK;
+ chconf |= OMAP3_MCSPI_CHCONF_TRM_RX_ONLY;
+ chconf |= OMAP3_MCSPI_CHCONF_FORCE;
+ writel(chconf, &ds->regs->channel[ds->slave.cs].chconf);
+
+ writel(0, &ds->regs->channel[ds->slave.cs].tx);
+
+ for (i = 0; i < len; i++) {
+ /* Wait till RX register contains data (RXS == 1) */
+ while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
+ OMAP3_MCSPI_CHSTAT_RXS)) {
+ if (--timeout <= 0) {
+ printf("SPI RXS timed out, status=0x%08x\n",
+ readl(&ds->regs->channel[ds->slave.cs].chstat));
+ return -1;
+ }
+ }
+ /* Read the data */
+ rxp[i] = readl(&ds->regs->channel[ds->slave.cs].rx);
+ }
+
+ if (flags & SPI_XFER_END) {
+ chconf &= ~OMAP3_MCSPI_CHCONF_FORCE;
+ writel(chconf, &ds->regs->channel[ds->slave.cs].chconf);
+
+ writel(0, &ds->regs->channel[ds->slave.cs].chctrl);
+ }
+
+ return 0;
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct omap3_spi_slave *ds = to_omap3_spi(slave);
+ unsigned int len;
+ const u8 *txp = dout;
+ u8 *rxp = din;
+ int ret = -1;
+
+ if (bitlen % 8)
+ return -1;
+
+ len = bitlen / 8;
+
+ if (bitlen == 0) { /* only change CS */
+ int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf);
+
+ if (flags & SPI_XFER_BEGIN) {
+ writel(OMAP3_MCSPI_CHCTRL_EN,
+ &ds->regs->channel[ds->slave.cs].chctrl);
+ chconf |= OMAP3_MCSPI_CHCONF_FORCE;
+ writel(chconf,
+ &ds->regs->channel[ds->slave.cs].chconf);
+ }
+ if (flags & SPI_XFER_END) {
+ chconf &= ~OMAP3_MCSPI_CHCONF_FORCE;
+ writel(chconf,
+ &ds->regs->channel[ds->slave.cs].chconf);
+ writel(0, &ds->regs->channel[ds->slave.cs].chctrl);
+ }
+ ret = 0;
+ } else {
+ if (dout != NULL)
+ ret = omap3_spi_write(slave, len, txp, flags);
+
+ if (din != NULL)
+ ret = omap3_spi_read(slave, len, rxp, flags);
+ }
+ return ret;
+}
+
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+ return 1;
+}
+
+void spi_cs_activate(struct spi_slave *slave)
+{
+}
+
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+}