*
* Copyright (C) 2007 Atmel Corporation
*
- * 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
+ * SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <spi.h>
if (!spi_cs_is_valid(bus, cs))
return NULL;
- ds = malloc(sizeof(*ds));
+ ds = spi_alloc_slave(struct davinci_spi_slave, bus, cs);
if (!ds)
return NULL;
ds->slave.bus = bus;
ds->slave.cs = cs;
- ds->regs = (struct davinci_spi_regs *)CONFIG_SYS_SPI_BASE;
+
+ switch (bus) {
+ case SPI0_BUS:
+ ds->regs = (struct davinci_spi_regs *)SPI0_BASE;
+ break;
+#ifdef CONFIG_SYS_SPI1
+ case SPI1_BUS:
+ ds->regs = (struct davinci_spi_regs *)SPI1_BASE;
+ break;
+#endif
+#ifdef CONFIG_SYS_SPI2
+ case SPI2_BUS:
+ ds->regs = (struct davinci_spi_regs *)SPI2_BASE;
+ break;
+#endif
+ default: /* Invalid bus number */
+ return NULL;
+ }
+
ds->freq = max_hz;
return &ds->slave;
int spi_claim_bus(struct spi_slave *slave)
{
struct davinci_spi_slave *ds = to_davinci_spi(slave);
- unsigned int scalar, data1_reg_val = 0;
+ unsigned int scalar;
/* Enable the SPI hardware */
writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
writel(SPIGCR1_MASTER_MASK | SPIGCR1_CLKMOD_MASK, &ds->regs->gcr1);
/* CS, CLK, SIMO and SOMI are functional pins */
- writel((SPIPC0_EN0FUN_MASK | SPIPC0_CLKFUN_MASK |
+ writel(((1 << slave->cs) | SPIPC0_CLKFUN_MASK |
SPIPC0_DOFUN_MASK | SPIPC0_DIFUN_MASK), &ds->regs->pc0);
/* setup format */
writel(8 | (scalar << SPIFMT_PRESCALE_SHIFT) |
(1 << SPIFMT_PHASE_SHIFT), &ds->regs->fmt0);
- /* hold cs active at end of transfer until explicitly de-asserted */
- data1_reg_val = (1 << SPIDAT1_CSHOLD_SHIFT) |
- (slave->cs << SPIDAT1_CSNR_SHIFT);
- writel(data1_reg_val, &ds->regs->dat1);
-
/*
* Including a minor delay. No science here. Should be good even with
* no delay
writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
}
-int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
- const void *dout, void *din, unsigned long flags)
+/*
+ * This functions needs to act like a macro to avoid pipeline reloads in the
+ * loops below. Use always_inline. This gains us about 160KiB/s and the bloat
+ * appears to be zero bytes (da830).
+ */
+__attribute__((always_inline))
+static inline u32 davinci_spi_xfer_data(struct davinci_spi_slave *ds, u32 data)
+{
+ u32 buf_reg_val;
+
+ /* send out data */
+ writel(data, &ds->regs->dat1);
+
+ /* wait for the data to clock in/out */
+ while ((buf_reg_val = readl(&ds->regs->buf)) & SPIBUF_RXEMPTY_MASK)
+ ;
+
+ return buf_reg_val;
+}
+
+static int davinci_spi_read(struct spi_slave *slave, unsigned int len,
+ u8 *rxp, unsigned long flags)
{
struct davinci_spi_slave *ds = to_davinci_spi(slave);
- unsigned int len, data1_reg_val = readl(&ds->regs->dat1);
- int ret, i;
- const u8 *txp = dout; /* dout can be NULL for read operation */
- u8 *rxp = din; /* din can be NULL for write operation */
+ unsigned int data1_reg_val;
+
+ /* enable CS hold, CS[n] and clear the data bits */
+ data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
+ (slave->cs << SPIDAT1_CSNR_SHIFT));
+
+ /* wait till TXFULL is deasserted */
+ while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
+ ;
+
+ /* preload the TX buffer to avoid clock starvation */
+ writel(data1_reg_val, &ds->regs->dat1);
- ret = 0;
+ /* keep reading 1 byte until only 1 byte left */
+ while ((len--) > 1)
+ *rxp++ = davinci_spi_xfer_data(ds, data1_reg_val);
+
+ /* clear CS hold when we reach the end */
+ if (flags & SPI_XFER_END)
+ data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
+
+ /* read the last byte */
+ *rxp = davinci_spi_xfer_data(ds, data1_reg_val);
+
+ return 0;
+}
+
+static int davinci_spi_write(struct spi_slave *slave, unsigned int len,
+ const u8 *txp, unsigned long flags)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+ unsigned int data1_reg_val;
+
+ /* enable CS hold and clear the data bits */
+ data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
+ (slave->cs << SPIDAT1_CSNR_SHIFT));
+
+ /* wait till TXFULL is deasserted */
+ while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
+ ;
+
+ /* preload the TX buffer to avoid clock starvation */
+ if (len > 2) {
+ writel(data1_reg_val | *txp++, &ds->regs->dat1);
+ len--;
+ }
+
+ /* keep writing 1 byte until only 1 byte left */
+ while ((len--) > 1)
+ davinci_spi_xfer_data(ds, data1_reg_val | *txp++);
+
+ /* clear CS hold when we reach the end */
+ if (flags & SPI_XFER_END)
+ data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
+
+ /* write the last byte */
+ davinci_spi_xfer_data(ds, data1_reg_val | *txp);
+
+ return 0;
+}
+
+#ifndef CONFIG_SPI_HALF_DUPLEX
+static int davinci_spi_read_write(struct spi_slave *slave, unsigned int len,
+ u8 *rxp, const u8 *txp, unsigned long flags)
+{
+ struct davinci_spi_slave *ds = to_davinci_spi(slave);
+ unsigned int data1_reg_val;
+
+ /* enable CS hold and clear the data bits */
+ data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
+ (slave->cs << SPIDAT1_CSNR_SHIFT));
+
+ /* wait till TXFULL is deasserted */
+ while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
+ ;
+
+ /* keep reading and writing 1 byte until only 1 byte left */
+ while ((len--) > 1)
+ *rxp++ = davinci_spi_xfer_data(ds, data1_reg_val | *txp++);
+
+ /* clear CS hold when we reach the end */
+ if (flags & SPI_XFER_END)
+ data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
+
+ /* read and write the last byte */
+ *rxp = davinci_spi_xfer_data(ds, data1_reg_val | *txp);
+
+ return 0;
+}
+#endif
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ unsigned int len;
if (bitlen == 0)
/* Finish any previously submitted transfers */
len = bitlen / 8;
- /* do an empty read to clear the current contents */
- readl(&ds->regs->buf);
-
- /* keep writing and reading 1 byte until done */
- for (i = 0; i < len; i++) {
- /* wait till TXFULL is asserted */
- while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK);
-
- /* write the data */
- data1_reg_val &= ~0xFFFF;
- if (txp) {
- data1_reg_val |= *txp;
- txp++;
- }
-
- /*
- * Write to DAT1 is required to keep the serial transfer going.
- * We just terminate when we reach the end.
- */
- if ((i == (len - 1)) && (flags & SPI_XFER_END)) {
- /* clear CS hold */
- writel(data1_reg_val &
- ~(1 << SPIDAT1_CSHOLD_SHIFT), &ds->regs->dat1);
- } else {
- /* enable CS hold */
- data1_reg_val |= ((1 << SPIDAT1_CSHOLD_SHIFT) |
- (slave->cs << SPIDAT1_CSNR_SHIFT));
- writel(data1_reg_val, &ds->regs->dat1);
- }
-
- /* read the data - wait for data availability */
- while (readl(&ds->regs->buf) & SPIBUF_RXEMPTY_MASK);
-
- if (rxp) {
- *rxp = readl(&ds->regs->buf) & 0xFF;
- rxp++;
- } else {
- /* simply drop the read character */
- readl(&ds->regs->buf);
- }
- }
- return 0;
+ if (!dout)
+ return davinci_spi_read(slave, len, din, flags);
+ else if (!din)
+ return davinci_spi_write(slave, len, dout, flags);
+#ifndef CONFIG_SPI_HALF_DUPLEX
+ else
+ return davinci_spi_read_write(slave, len, din, dout, flags);
+#else
+ printf("SPI full duplex transaction requested with "
+ "CONFIG_SPI_HALF_DUPLEX defined.\n");
+ flags |= SPI_XFER_END;
+#endif
out:
if (flags & SPI_XFER_END) {
- writel(data1_reg_val &
- ~(1 << SPIDAT1_CSHOLD_SHIFT), &ds->regs->dat1);
+ u8 dummy = 0;
+ davinci_spi_write(slave, 1, &dummy, flags);
}
return 0;
}
int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
- return bus == 0 && cs == 0;
+ int ret = 0;
+
+ switch (bus) {
+ case SPI0_BUS:
+ if (cs < SPI0_NUM_CS)
+ ret = 1;
+ break;
+#ifdef CONFIG_SYS_SPI1
+ case SPI1_BUS:
+ if (cs < SPI1_NUM_CS)
+ ret = 1;
+ break;
+#endif
+#ifdef CONFIG_SYS_SPI2
+ case SPI2_BUS:
+ if (cs < SPI2_NUM_CS)
+ ret = 1;
+ break;
+#endif
+ default:
+ /* Invalid bus number. Do nothing */
+ break;
+ }
+ return ret;
}
void spi_cs_activate(struct spi_slave *slave)
projects / karo-tx-uboot.git / blobdiff