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// SPDX-License-Identifier: GPL-2.0+
/*
* Freescale i.MX28 SPI driver
*
* Copyright (C) 2019 DENX Software Engineering
* Lukasz Majewski, DENX Software Engineering, lukma@denx.de
*
* Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
* on behalf of DENX Software Engineering GmbH
*
* NOTE: This driver only supports the SPI-controller chipselects,
* GPIO driven chipselects are not supported.
*/
#include <common.h>
#include <dm.h>
#include <dt-structs.h>
#include <cpu_func.h>
#include <errno.h>
#include <log.h>
#include <malloc.h>
#include <memalign.h>
#include <spi.h>
#include <asm/cache.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/sys_proto.h>
#include <asm/mach-imx/dma.h>
#define MXS_SPI_MAX_TIMEOUT 1000000
#define MXS_SPI_PORT_OFFSET 0x2000
#define MXS_SSP_CHIPSELECT_MASK 0x00300000
#define MXS_SSP_CHIPSELECT_SHIFT 20
#define MXSSSP_SMALL_TRANSFER 512
/* Base numbers of i.MX2[38] clk for ssp0 IP block */
#define MXS_SSP_IMX23_CLKID_SSP0 33
#define MXS_SSP_IMX28_CLKID_SSP0 46
struct mxs_spi_plat {
#if CONFIG_IS_ENABLED(OF_PLATDATA)
struct dtd_fsl_imx23_spi dtplat;
#endif
s32 frequency; /* Default clock frequency, -1 for none */
fdt_addr_t base; /* SPI IP block base address */
int num_cs; /* Number of CSes supported */
int dma_id; /* ID of the DMA channel */
int clk_id; /* ID of the SSP clock */
};
struct mxs_spi_priv {
struct mxs_ssp_regs *regs;
unsigned int dma_channel;
unsigned int max_freq;
unsigned int clk_id;
unsigned int mode;
};
static void mxs_spi_start_xfer(struct mxs_ssp_regs *ssp_regs)
{
writel(SSP_CTRL0_LOCK_CS, &ssp_regs->hw_ssp_ctrl0_set);
writel(SSP_CTRL0_IGNORE_CRC, &ssp_regs->hw_ssp_ctrl0_clr);
}
static void mxs_spi_end_xfer(struct mxs_ssp_regs *ssp_regs)
{
writel(SSP_CTRL0_LOCK_CS, &ssp_regs->hw_ssp_ctrl0_clr);
writel(SSP_CTRL0_IGNORE_CRC, &ssp_regs->hw_ssp_ctrl0_set);
}
static int mxs_spi_xfer_pio(struct mxs_spi_priv *priv,
char *data, int length, int write,
unsigned long flags)
{
struct mxs_ssp_regs *ssp_regs = priv->regs;
if (flags & SPI_XFER_BEGIN)
mxs_spi_start_xfer(ssp_regs);
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);
if (write)
writel(SSP_CTRL0_READ, &ssp_regs->hw_ssp_ctrl0_clr);
else
writel(SSP_CTRL0_READ, &ssp_regs->hw_ssp_ctrl0_set);
writel(SSP_CTRL0_RUN, &ssp_regs->hw_ssp_ctrl0_set);
if (mxs_wait_mask_set(&ssp_regs->hw_ssp_ctrl0_reg,
SSP_CTRL0_RUN, MXS_SPI_MAX_TIMEOUT)) {
printf("MXS SPI: Timeout waiting for start\n");
return -ETIMEDOUT;
}
if (write)
writel(*data++, &ssp_regs->hw_ssp_data);
writel(SSP_CTRL0_DATA_XFER, &ssp_regs->hw_ssp_ctrl0_set);
if (!write) {
if (mxs_wait_mask_clr(&ssp_regs->hw_ssp_status_reg,
SSP_STATUS_FIFO_EMPTY, MXS_SPI_MAX_TIMEOUT)) {
printf("MXS SPI: Timeout waiting for data\n");
return -ETIMEDOUT;
}
*data = readl(&ssp_regs->hw_ssp_data);
data++;
}
if (mxs_wait_mask_clr(&ssp_regs->hw_ssp_ctrl0_reg,
SSP_CTRL0_RUN, MXS_SPI_MAX_TIMEOUT)) {
printf("MXS SPI: Timeout waiting for finish\n");
return -ETIMEDOUT;
}
}
return 0;
}
static int mxs_spi_xfer_dma(struct mxs_spi_priv *priv,
char *data, int length, int write,
unsigned long flags)
{ struct mxs_ssp_regs *ssp_regs = priv->regs;
const int xfer_max_sz = 0xff00;
const int desc_count = DIV_ROUND_UP(length, xfer_max_sz) + 1;
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;
#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 (!write)
ctrl0 |= SSP_CTRL0_READ;
if (length % ARCH_DMA_MINALIGN)
cache_data_count = roundup(length, ARCH_DMA_MINALIGN);
else
cache_data_count = length;
/* Flush data to DRAM so DMA can pick them up */
if (write)
flush_dcache_range(dstart, dstart + cache_data_count);
/* Invalidate the area, so no writeback into the RAM races with DMA */
invalidate_dcache_range(dstart, dstart + cache_data_count);
dmach = priv->dma_channel;
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++;
}
if (mxs_dma_go(dmach))
ret = -EINVAL;
/* The data arrived into DRAM, invalidate cache over them */
if (!write)
invalidate_dcache_range(dstart, dstart + cache_data_count);
return ret;
}
int mxs_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev_get_parent(dev);
struct mxs_spi_priv *priv = dev_get_priv(bus);
struct mxs_ssp_regs *ssp_regs = priv->regs;
int len = bitlen / 8;
char dummy;
int write = 0;
char *data = NULL;
int dma = 1;
if (bitlen == 0) {
if (flags & SPI_XFER_END) {
din = (void *)&dummy;
len = 1;
} else
return 0;
}
/* Half-duplex only */
if (din && dout)
return -EINVAL;
/* No data */
if (!din && !dout)
return 0;
if (dout) {
data = (char *)dout;
write = 1;
} else if (din) {
data = (char *)din;
write = 0;
}
/*
* Check for alignment, if the buffer is aligned, do DMA transfer,
* PIO otherwise. This is a temporary workaround until proper bounce
* buffer is in place.
*/
if (dma) {
if (((uint32_t)data) & (ARCH_DMA_MINALIGN - 1))
dma = 0;
if (((uint32_t)len) & (ARCH_DMA_MINALIGN - 1))
dma = 0;
}
if (!dma || (len < MXSSSP_SMALL_TRANSFER)) {
writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_clr);
return mxs_spi_xfer_pio(priv, data, len, write, flags);
} else {
writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_set);
return mxs_spi_xfer_dma(priv, data, len, write, flags);
}
}
static int mxs_spi_probe(struct udevice *bus)
{
struct mxs_spi_plat *plat = dev_get_plat(bus);
struct mxs_spi_priv *priv = dev_get_priv(bus);
int ret;
debug("%s: probe\n", __func__);
#if CONFIG_IS_ENABLED(OF_PLATDATA)
struct dtd_fsl_imx23_spi *dtplat = &plat->dtplat;
struct phandle_1_arg *p1a = &dtplat->clocks[0];
priv->regs = (struct mxs_ssp_regs *)dtplat->reg[0];
priv->dma_channel = dtplat->dmas[1];
priv->clk_id = p1a->arg[0];
priv->max_freq = dtplat->spi_max_frequency;
plat->num_cs = dtplat->num_cs;
debug("OF_PLATDATA: regs: 0x%x max freq: %d clkid: %d\n",
(unsigned int)priv->regs, priv->max_freq, priv->clk_id);
#else
priv->regs = (struct mxs_ssp_regs *)plat->base;
priv->max_freq = plat->frequency;
priv->dma_channel = plat->dma_id;
priv->clk_id = plat->clk_id;
#endif
mxs_reset_block(&priv->regs->hw_ssp_ctrl0_reg);
ret = mxs_dma_init_channel(priv->dma_channel);
if (ret) {
printf("%s: DMA init channel error %d\n", __func__, ret);
return ret;
}
return 0;
}
static int mxs_spi_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct mxs_spi_priv *priv = dev_get_priv(bus);
struct mxs_ssp_regs *ssp_regs = priv->regs;
int cs = spi_chip_select(dev);
/*
* i.MX28 supports up to 3 CS (SSn0, SSn1, SSn2)
* To set them it uses following tuple (WAIT_FOR_IRQ,WAIT_FOR_CMD),
* where:
*
* WAIT_FOR_IRQ is bit 21 of HW_SSP_CTRL0
* WAIT_FOR_CMD is bit 20 (#defined as MXS_SSP_CHIPSELECT_SHIFT here) of
* HW_SSP_CTRL0
* SSn0 b00
* SSn1 b01
* SSn2 b10 (which require setting WAIT_FOR_IRQ)
*
* However, for now i.MX28 SPI driver will support up till 2 CSes
* (SSn0, and SSn1).
*/
/* Ungate SSP clock and set active CS */
clrsetbits_le32(&ssp_regs->hw_ssp_ctrl0,
BIT(MXS_SSP_CHIPSELECT_SHIFT) |
SSP_CTRL0_CLKGATE, (cs << MXS_SSP_CHIPSELECT_SHIFT));
return 0;
}
static int mxs_spi_release_bus(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct mxs_spi_priv *priv = dev_get_priv(bus);
struct mxs_ssp_regs *ssp_regs = priv->regs;
/* Gate SSP clock */
setbits_le32(&ssp_regs->hw_ssp_ctrl0, SSP_CTRL0_CLKGATE);
return 0;
}
static int mxs_spi_set_speed(struct udevice *bus, uint speed)
{
struct mxs_spi_priv *priv = dev_get_priv(bus);
#ifdef CONFIG_MX28
int clkid = priv->clk_id - MXS_SSP_IMX28_CLKID_SSP0;
#else /* CONFIG_MX23 */
int clkid = priv->clk_id - MXS_SSP_IMX23_CLKID_SSP0;
#endif
if (speed > priv->max_freq)
speed = priv->max_freq;
debug("%s speed: %u [Hz] clkid: %d\n", __func__, speed, clkid);
mxs_set_ssp_busclock(clkid, speed / 1000);
return 0;
}
static int mxs_spi_set_mode(struct udevice *bus, uint mode)
{
struct mxs_spi_priv *priv = dev_get_priv(bus);
struct mxs_ssp_regs *ssp_regs = priv->regs;
u32 reg;
priv->mode = mode;
debug("%s: mode 0x%x\n", __func__, mode);
reg = SSP_CTRL1_SSP_MODE_SPI | SSP_CTRL1_WORD_LENGTH_EIGHT_BITS;
reg |= (priv->mode & SPI_CPOL) ? SSP_CTRL1_POLARITY : 0;
reg |= (priv->mode & SPI_CPHA) ? SSP_CTRL1_PHASE : 0;
writel(reg, &ssp_regs->hw_ssp_ctrl1);
/* Single bit SPI support */
writel(SSP_CTRL0_BUS_WIDTH_ONE_BIT, &ssp_regs->hw_ssp_ctrl0);
return 0;
}
static const struct dm_spi_ops mxs_spi_ops = {
.claim_bus = mxs_spi_claim_bus,
.release_bus = mxs_spi_release_bus,
.xfer = mxs_spi_xfer,
.set_speed = mxs_spi_set_speed,
.set_mode = mxs_spi_set_mode,
/*
* cs_info is not needed, since we require all chip selects to be
* in the device tree explicitly
*/
};
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
static int mxs_of_to_plat(struct udevice *bus)
{
struct mxs_spi_plat *plat = dev_get_plat(bus);
u32 prop[2];
int ret;
plat->base = dev_read_addr(bus);
plat->frequency =
dev_read_u32_default(bus, "spi-max-frequency", 40000000);
plat->num_cs = dev_read_u32_default(bus, "num-cs", 2);
ret = dev_read_u32_array(bus, "dmas", prop, ARRAY_SIZE(prop));
if (ret) {
printf("%s: Reading 'dmas' property failed!\n", __func__);
return ret;
}
plat->dma_id = prop[1];
ret = dev_read_u32_array(bus, "clocks", prop, ARRAY_SIZE(prop));
if (ret) {
printf("%s: Reading 'clocks' property failed!\n", __func__);
return ret;
}
plat->clk_id = prop[1];
debug("%s: base=0x%x, max-frequency=%d num-cs=%d dma_id=%d clk_id=%d\n",
__func__, (uint)plat->base, plat->frequency, plat->num_cs,
plat->dma_id, plat->clk_id);
return 0;
}
static const struct udevice_id mxs_spi_ids[] = {
{ .compatible = "fsl,imx23-spi" },
{ .compatible = "fsl,imx28-spi" },
{ }
};
#endif
U_BOOT_DRIVER(fsl_imx23_spi) = {
.name = "fsl_imx23_spi",
.id = UCLASS_SPI,
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
.of_match = mxs_spi_ids,
.of_to_plat = mxs_of_to_plat,
#endif
.plat_auto = sizeof(struct mxs_spi_plat),
.ops = &mxs_spi_ops,
.priv_auto = sizeof(struct mxs_spi_priv),
.probe = mxs_spi_probe,
};
U_BOOT_DRIVER_ALIAS(fsl_imx23_spi, fsl_imx28_spi)