* Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
* on behalf of DENX Software Engineering GmbH
*
- * 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+
*
* NOTE: This driver only supports the SPI-controller chipselects,
* GPIO driven chipselects are not supported.
#include <asm/arch/clock.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/sys_proto.h>
-#include <asm/arch/dma.h>
+#include <asm/imx-common/dma.h>
#define MXS_SPI_MAX_TIMEOUT 1000000
#define MXS_SPI_PORT_OFFSET 0x2000
#define MXSSSP_SMALL_TRANSFER 512
-/*
- * CONFIG_MXS_SPI_DMA_ENABLE: Experimental mixed PIO/DMA support for MXS SPI
- * host. Use with utmost caution!
- *
- * Enabling this is not yet recommended since this
- * still doesn't support transfers to/from unaligned
- * addresses. Therefore this driver will not work
- * for example with saving environment. This is
- * caused by DMA alignment constraints on MXS.
- */
-
struct mxs_spi_slave {
struct spi_slave slave;
uint32_t max_khz;
uint32_t mode;
struct mxs_ssp_regs *regs;
- struct mxs_dma_desc *desc;
};
static inline struct mxs_spi_slave *to_mxs_slave(struct spi_slave *slave)
int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
/* MXS SPI: 4 ports and 3 chip selects maximum */
- if (bus > 3 || cs > 2)
+ if (!mxs_ssp_bus_id_valid(bus) || cs > 2)
return 0;
else
return 1;
unsigned int max_hz, unsigned int mode)
{
struct mxs_spi_slave *mxs_slave;
- uint32_t addr;
- struct mxs_ssp_regs *ssp_regs;
- int reg;
- struct mxs_dma_desc *desc;
if (!spi_cs_is_valid(bus, cs)) {
printf("mxs_spi: invalid bus %d / chip select %d\n", bus, cs);
return NULL;
}
- mxs_slave = malloc(sizeof(struct mxs_spi_slave));
+ mxs_slave = spi_alloc_slave(struct mxs_spi_slave, bus, cs);
if (!mxs_slave)
return NULL;
- desc = mxs_dma_desc_alloc();
- if (!desc)
- goto err_desc;
-
- if (mxs_dma_init_channel(bus))
+ if (mxs_dma_init_channel(MXS_DMA_CHANNEL_AHB_APBH_SSP0 + bus))
goto err_init;
- addr = MXS_SSP0_BASE + (bus * MXS_SPI_PORT_OFFSET);
-
- mxs_slave->slave.bus = bus;
- mxs_slave->slave.cs = cs;
mxs_slave->max_khz = max_hz / 1000;
mxs_slave->mode = mode;
- mxs_slave->regs = (struct mxs_ssp_regs *)addr;
- mxs_slave->desc = desc;
- ssp_regs = mxs_slave->regs;
+ mxs_slave->regs = mxs_ssp_regs_by_bus(bus);
- reg = readl(&ssp_regs->hw_ssp_ctrl0);
- reg &= ~(MXS_SSP_CHIPSELECT_MASK);
- reg |= cs << MXS_SSP_CHIPSELECT_SHIFT;
-
- writel(reg, &ssp_regs->hw_ssp_ctrl0);
return &mxs_slave->slave;
err_init:
- mxs_dma_desc_free(desc);
-err_desc:
free(mxs_slave);
return NULL;
}
void spi_free_slave(struct spi_slave *slave)
{
struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave);
- mxs_dma_desc_free(mxs_slave->desc);
free(mxs_slave);
}
mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
- writel(SSP_CTRL0_BUS_WIDTH_ONE_BIT, &ssp_regs->hw_ssp_ctrl0);
+ writel((slave->cs << MXS_SSP_CHIPSELECT_SHIFT) |
+ SSP_CTRL0_BUS_WIDTH_ONE_BIT,
+ &ssp_regs->hw_ssp_ctrl0);
reg = SSP_CTRL1_SSP_MODE_SPI | SSP_CTRL1_WORD_LENGTH_EIGHT_BITS;
reg |= (mxs_slave->mode & SPI_CPOL) ? SSP_CTRL1_POLARITY : 0;
writel(0, &ssp_regs->hw_ssp_cmd0);
- mx28_set_ssp_busclock(slave->bus, mxs_slave->max_khz);
+ mxs_set_ssp_busclock(slave->bus, mxs_slave->max_khz);
return 0;
}
while (length--) {
/* We transfer 1 byte */
+#if defined(CONFIG_MX23)
+ writel(SSP_CTRL0_XFER_COUNT_MASK, &ssp_regs->hw_ssp_ctrl0_clr);
+ writel(1, &ssp_regs->hw_ssp_ctrl0_set);
+#elif defined(CONFIG_MX28)
writel(1, &ssp_regs->hw_ssp_xfer_size);
+#endif
if ((flags & SPI_XFER_END) && !length)
mxs_spi_end_xfer(ssp_regs);
static int mxs_spi_xfer_dma(struct mxs_spi_slave *slave,
char *data, int length, int write, unsigned long flags)
{
- struct mxs_dma_desc *desc = slave->desc;
+ const int xfer_max_sz = 0xff00;
+ const int desc_count = DIV_ROUND_UP(length, xfer_max_sz) + 1;
struct mxs_ssp_regs *ssp_regs = slave->regs;
- uint32_t ctrl0 = SSP_CTRL0_DATA_XFER;
+ struct mxs_dma_desc *dp;
+ uint32_t ctrl0;
uint32_t cache_data_count;
+ const uint32_t dstart = (uint32_t)data;
int dmach;
+ int tl;
+ int ret = 0;
- memset(desc, 0, sizeof(struct mxs_dma_desc));
- desc->address = (dma_addr_t)desc;
+#if defined(CONFIG_MX23)
+ const int mxs_spi_pio_words = 1;
+#elif defined(CONFIG_MX28)
+ const int mxs_spi_pio_words = 4;
+#endif
+
+ ALLOC_CACHE_ALIGN_BUFFER(struct mxs_dma_desc, desc, desc_count);
+
+ memset(desc, 0, sizeof(struct mxs_dma_desc) * desc_count);
+
+ ctrl0 = readl(&ssp_regs->hw_ssp_ctrl0);
+ ctrl0 |= SSP_CTRL0_DATA_XFER;
if (flags & SPI_XFER_BEGIN)
ctrl0 |= SSP_CTRL0_LOCK_CS;
- if (flags & SPI_XFER_END)
- ctrl0 |= SSP_CTRL0_IGNORE_CRC;
if (!write)
ctrl0 |= SSP_CTRL0_READ;
- writel(length, &ssp_regs->hw_ssp_xfer_size);
-
if (length % ARCH_DMA_MINALIGN)
cache_data_count = roundup(length, ARCH_DMA_MINALIGN);
else
cache_data_count = length;
- if (!write) {
- slave->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_WRITE;
- slave->desc->cmd.address = (dma_addr_t)data;
- } else {
- slave->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_READ;
- slave->desc->cmd.address = (dma_addr_t)data;
+ /* Flush data to DRAM so DMA can pick them up */
+ if (write)
+ flush_dcache_range(dstart, dstart + cache_data_count);
- /* Flush data to DRAM so DMA can pick them up */
- flush_dcache_range((uint32_t)data,
- (uint32_t)(data + cache_data_count));
- }
+ /* Invalidate the area, so no writeback into the RAM races with DMA */
+ invalidate_dcache_range(dstart, dstart + cache_data_count);
- slave->desc->cmd.data |= MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM |
- (length << MXS_DMA_DESC_BYTES_OFFSET) |
- (1 << MXS_DMA_DESC_PIO_WORDS_OFFSET) |
- MXS_DMA_DESC_WAIT4END;
+ dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + slave->slave.bus;
- slave->desc->cmd.pio_words[0] = ctrl0;
+ dp = desc;
+ while (length) {
+ dp->address = (dma_addr_t)dp;
+ dp->cmd.address = (dma_addr_t)data;
+
+ /*
+ * This is correct, even though it does indeed look insane.
+ * I hereby have to, wholeheartedly, thank Freescale Inc.,
+ * for always inventing insane hardware and keeping me busy
+ * and employed ;-)
+ */
+ if (write)
+ dp->cmd.data = MXS_DMA_DESC_COMMAND_DMA_READ;
+ else
+ dp->cmd.data = MXS_DMA_DESC_COMMAND_DMA_WRITE;
+
+ /*
+ * The DMA controller can transfer large chunks (64kB) at
+ * time by setting the transfer length to 0. Setting tl to
+ * 0x10000 will overflow below and make .data contain 0.
+ * Otherwise, 0xff00 is the transfer maximum.
+ */
+ if (length >= 0x10000)
+ tl = 0x10000;
+ else
+ tl = min(length, xfer_max_sz);
+
+ dp->cmd.data |=
+ ((tl & 0xffff) << MXS_DMA_DESC_BYTES_OFFSET) |
+ (mxs_spi_pio_words << MXS_DMA_DESC_PIO_WORDS_OFFSET) |
+ MXS_DMA_DESC_HALT_ON_TERMINATE |
+ MXS_DMA_DESC_TERMINATE_FLUSH;
+
+ data += tl;
+ length -= tl;
+
+ if (!length) {
+ dp->cmd.data |= MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM;
+
+ if (flags & SPI_XFER_END) {
+ ctrl0 &= ~SSP_CTRL0_LOCK_CS;
+ ctrl0 |= SSP_CTRL0_IGNORE_CRC;
+ }
+ }
+
+ /*
+ * Write CTRL0, CMD0, CMD1 and XFER_SIZE registers in
+ * case of MX28, write only CTRL0 in case of MX23 due
+ * to the difference in register layout. It is utterly
+ * essential that the XFER_SIZE register is written on
+ * a per-descriptor basis with the same size as is the
+ * descriptor!
+ */
+ dp->cmd.pio_words[0] = ctrl0;
+#ifdef CONFIG_MX28
+ dp->cmd.pio_words[1] = 0;
+ dp->cmd.pio_words[2] = 0;
+ dp->cmd.pio_words[3] = tl;
+#endif
+
+ mxs_dma_desc_append(dmach, dp);
+
+ dp++;
+ }
- dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + slave->slave.bus;
- mxs_dma_desc_append(dmach, slave->desc);
if (mxs_dma_go(dmach))
- return -EINVAL;
+ ret = -EINVAL;
/* The data arrived into DRAM, invalidate cache over them */
- if (!write) {
- invalidate_dcache_range((uint32_t)data,
- (uint32_t)(data + cache_data_count));
- }
+ if (!write)
+ invalidate_dcache_range(dstart, dstart + cache_data_count);
- return 0;
+ return ret;
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
char dummy;
int write = 0;
char *data = NULL;
-
-#ifdef CONFIG_MXS_SPI_DMA_ENABLE
int dma = 1;
-#else
- int dma = 0;
-#endif
if (bitlen == 0) {
if (flags & SPI_XFER_END) {
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