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linux/drivers/spi/spi-imx.c
Robin Gong f62caccd12 spi: spi-imx: add DMA support
Enable DMA support on i.mx6. The read speed can increase from 600KB/s
to 1.2MB/s on i.mx6q. You can disable or enable dma function in dts.
If not set "dma-names" in dts, spi will use PIO mode. This patch only
validate on i.mx6, not i.mx5, but encourage ones to apply this patch
on i.mx5 since they share the same IP.

Note:
  Sometime, there is a weid data in rxfifo after one full tx/rx
transfer finish by DMA on i.mx6dl, so we disable dma functhion on
i.mx6dl.

Signed-off-by: Frank Li <Frank.Li@freescale.com>
Signed-off-by: Robin Gong <b38343@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-09-17 11:36:11 -07:00

1247 lines
33 KiB
C

/*
* Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright (C) 2008 Juergen Beisert
*
* 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
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301, USA.
*/
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/types.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/platform_data/dma-imx.h>
#include <linux/platform_data/spi-imx.h>
#define DRIVER_NAME "spi_imx"
#define MXC_CSPIRXDATA 0x00
#define MXC_CSPITXDATA 0x04
#define MXC_CSPICTRL 0x08
#define MXC_CSPIINT 0x0c
#define MXC_RESET 0x1c
/* generic defines to abstract from the different register layouts */
#define MXC_INT_RR (1 << 0) /* Receive data ready interrupt */
#define MXC_INT_TE (1 << 1) /* Transmit FIFO empty interrupt */
/* The maximum bytes that a sdma BD can transfer.*/
#define MAX_SDMA_BD_BYTES (1 << 15)
#define IMX_DMA_TIMEOUT (msecs_to_jiffies(3000))
struct spi_imx_config {
unsigned int speed_hz;
unsigned int bpw;
unsigned int mode;
u8 cs;
};
enum spi_imx_devtype {
IMX1_CSPI,
IMX21_CSPI,
IMX27_CSPI,
IMX31_CSPI,
IMX35_CSPI, /* CSPI on all i.mx except above */
IMX51_ECSPI, /* ECSPI on i.mx51 and later */
};
struct spi_imx_data;
struct spi_imx_devtype_data {
void (*intctrl)(struct spi_imx_data *, int);
int (*config)(struct spi_imx_data *, struct spi_imx_config *);
void (*trigger)(struct spi_imx_data *);
int (*rx_available)(struct spi_imx_data *);
void (*reset)(struct spi_imx_data *);
enum spi_imx_devtype devtype;
};
struct spi_imx_data {
struct spi_bitbang bitbang;
struct completion xfer_done;
void __iomem *base;
int irq;
struct clk *clk_per;
struct clk *clk_ipg;
unsigned long spi_clk;
unsigned int count;
void (*tx)(struct spi_imx_data *);
void (*rx)(struct spi_imx_data *);
void *rx_buf;
const void *tx_buf;
unsigned int txfifo; /* number of words pushed in tx FIFO */
/* DMA */
unsigned int dma_is_inited;
unsigned int dma_finished;
bool usedma;
u32 rx_wml;
u32 tx_wml;
u32 rxt_wml;
struct completion dma_rx_completion;
struct completion dma_tx_completion;
const struct spi_imx_devtype_data *devtype_data;
int chipselect[0];
};
static inline int is_imx27_cspi(struct spi_imx_data *d)
{
return d->devtype_data->devtype == IMX27_CSPI;
}
static inline int is_imx35_cspi(struct spi_imx_data *d)
{
return d->devtype_data->devtype == IMX35_CSPI;
}
static inline unsigned spi_imx_get_fifosize(struct spi_imx_data *d)
{
return (d->devtype_data->devtype == IMX51_ECSPI) ? 64 : 8;
}
#define MXC_SPI_BUF_RX(type) \
static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx) \
{ \
unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA); \
\
if (spi_imx->rx_buf) { \
*(type *)spi_imx->rx_buf = val; \
spi_imx->rx_buf += sizeof(type); \
} \
}
#define MXC_SPI_BUF_TX(type) \
static void spi_imx_buf_tx_##type(struct spi_imx_data *spi_imx) \
{ \
type val = 0; \
\
if (spi_imx->tx_buf) { \
val = *(type *)spi_imx->tx_buf; \
spi_imx->tx_buf += sizeof(type); \
} \
\
spi_imx->count -= sizeof(type); \
\
writel(val, spi_imx->base + MXC_CSPITXDATA); \
}
MXC_SPI_BUF_RX(u8)
MXC_SPI_BUF_TX(u8)
MXC_SPI_BUF_RX(u16)
MXC_SPI_BUF_TX(u16)
MXC_SPI_BUF_RX(u32)
MXC_SPI_BUF_TX(u32)
/* First entry is reserved, second entry is valid only if SDHC_SPIEN is set
* (which is currently not the case in this driver)
*/
static int mxc_clkdivs[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
256, 384, 512, 768, 1024};
/* MX21, MX27 */
static unsigned int spi_imx_clkdiv_1(unsigned int fin,
unsigned int fspi, unsigned int max)
{
int i;
for (i = 2; i < max; i++)
if (fspi * mxc_clkdivs[i] >= fin)
return i;
return max;
}
/* MX1, MX31, MX35, MX51 CSPI */
static unsigned int spi_imx_clkdiv_2(unsigned int fin,
unsigned int fspi)
{
int i, div = 4;
for (i = 0; i < 7; i++) {
if (fspi * div >= fin)
return i;
div <<= 1;
}
return 7;
}
static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
struct spi_transfer *transfer)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
if (spi_imx->dma_is_inited && (transfer->len > spi_imx->rx_wml)
&& (transfer->len > spi_imx->tx_wml))
return true;
return false;
}
#define MX51_ECSPI_CTRL 0x08
#define MX51_ECSPI_CTRL_ENABLE (1 << 0)
#define MX51_ECSPI_CTRL_XCH (1 << 2)
#define MX51_ECSPI_CTRL_SMC (1 << 3)
#define MX51_ECSPI_CTRL_MODE_MASK (0xf << 4)
#define MX51_ECSPI_CTRL_POSTDIV_OFFSET 8
#define MX51_ECSPI_CTRL_PREDIV_OFFSET 12
#define MX51_ECSPI_CTRL_CS(cs) ((cs) << 18)
#define MX51_ECSPI_CTRL_BL_OFFSET 20
#define MX51_ECSPI_CONFIG 0x0c
#define MX51_ECSPI_CONFIG_SCLKPHA(cs) (1 << ((cs) + 0))
#define MX51_ECSPI_CONFIG_SCLKPOL(cs) (1 << ((cs) + 4))
#define MX51_ECSPI_CONFIG_SBBCTRL(cs) (1 << ((cs) + 8))
#define MX51_ECSPI_CONFIG_SSBPOL(cs) (1 << ((cs) + 12))
#define MX51_ECSPI_CONFIG_SCLKCTL(cs) (1 << ((cs) + 20))
#define MX51_ECSPI_INT 0x10
#define MX51_ECSPI_INT_TEEN (1 << 0)
#define MX51_ECSPI_INT_RREN (1 << 3)
#define MX51_ECSPI_DMA 0x14
#define MX51_ECSPI_DMA_TX_WML_OFFSET 0
#define MX51_ECSPI_DMA_TX_WML_MASK 0x3F
#define MX51_ECSPI_DMA_RX_WML_OFFSET 16
#define MX51_ECSPI_DMA_RX_WML_MASK (0x3F << 16)
#define MX51_ECSPI_DMA_RXT_WML_OFFSET 24
#define MX51_ECSPI_DMA_RXT_WML_MASK (0x3F << 24)
#define MX51_ECSPI_DMA_TEDEN_OFFSET 7
#define MX51_ECSPI_DMA_RXDEN_OFFSET 23
#define MX51_ECSPI_DMA_RXTDEN_OFFSET 31
#define MX51_ECSPI_STAT 0x18
#define MX51_ECSPI_STAT_RR (1 << 3)
/* MX51 eCSPI */
static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi,
unsigned int *fres)
{
/*
* there are two 4-bit dividers, the pre-divider divides by
* $pre, the post-divider by 2^$post
*/
unsigned int pre, post;
if (unlikely(fspi > fin))
return 0;
post = fls(fin) - fls(fspi);
if (fin > fspi << post)
post++;
/* now we have: (fin <= fspi << post) with post being minimal */
post = max(4U, post) - 4;
if (unlikely(post > 0xf)) {
pr_err("%s: cannot set clock freq: %u (base freq: %u)\n",
__func__, fspi, fin);
return 0xff;
}
pre = DIV_ROUND_UP(fin, fspi << post) - 1;
pr_debug("%s: fin: %u, fspi: %u, post: %u, pre: %u\n",
__func__, fin, fspi, post, pre);
/* Resulting frequency for the SCLK line. */
*fres = (fin / (pre + 1)) >> post;
return (pre << MX51_ECSPI_CTRL_PREDIV_OFFSET) |
(post << MX51_ECSPI_CTRL_POSTDIV_OFFSET);
}
static void __maybe_unused mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned val = 0;
if (enable & MXC_INT_TE)
val |= MX51_ECSPI_INT_TEEN;
if (enable & MXC_INT_RR)
val |= MX51_ECSPI_INT_RREN;
writel(val, spi_imx->base + MX51_ECSPI_INT);
}
static void __maybe_unused mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
{
u32 reg = readl(spi_imx->base + MX51_ECSPI_CTRL);
if (!spi_imx->usedma)
reg |= MX51_ECSPI_CTRL_XCH;
else if (!spi_imx->dma_finished)
reg |= MX51_ECSPI_CTRL_SMC;
else
reg &= ~MX51_ECSPI_CTRL_SMC;
writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
}
static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0;
u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg;
u32 clk = config->speed_hz, delay;
/*
* The hardware seems to have a race condition when changing modes. The
* current assumption is that the selection of the channel arrives
* earlier in the hardware than the mode bits when they are written at
* the same time.
* So set master mode for all channels as we do not support slave mode.
*/
ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
/* set clock speed */
ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz, &clk);
/* set chip select to use */
ctrl |= MX51_ECSPI_CTRL_CS(config->cs);
ctrl |= (config->bpw - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
cfg |= MX51_ECSPI_CONFIG_SBBCTRL(config->cs);
if (config->mode & SPI_CPHA)
cfg |= MX51_ECSPI_CONFIG_SCLKPHA(config->cs);
if (config->mode & SPI_CPOL) {
cfg |= MX51_ECSPI_CONFIG_SCLKPOL(config->cs);
cfg |= MX51_ECSPI_CONFIG_SCLKCTL(config->cs);
}
if (config->mode & SPI_CS_HIGH)
cfg |= MX51_ECSPI_CONFIG_SSBPOL(config->cs);
writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
/*
* Wait until the changes in the configuration register CONFIGREG
* propagate into the hardware. It takes exactly one tick of the
* SCLK clock, but we will wait two SCLK clock just to be sure. The
* effect of the delay it takes for the hardware to apply changes
* is noticable if the SCLK clock run very slow. In such a case, if
* the polarity of SCLK should be inverted, the GPIO ChipSelect might
* be asserted before the SCLK polarity changes, which would disrupt
* the SPI communication as the device on the other end would consider
* the change of SCLK polarity as a clock tick already.
*/
delay = (2 * 1000000) / clk;
if (likely(delay < 10)) /* SCLK is faster than 100 kHz */
udelay(delay);
else /* SCLK is _very_ slow */
usleep_range(delay, delay + 10);
/*
* Configure the DMA register: setup the watermark
* and enable DMA request.
*/
if (spi_imx->dma_is_inited) {
dma = readl(spi_imx->base + MX51_ECSPI_DMA);
spi_imx->tx_wml = spi_imx_get_fifosize(spi_imx) / 2;
spi_imx->rx_wml = spi_imx_get_fifosize(spi_imx) / 2;
spi_imx->rxt_wml = spi_imx_get_fifosize(spi_imx) / 2;
rx_wml_cfg = spi_imx->rx_wml << MX51_ECSPI_DMA_RX_WML_OFFSET;
tx_wml_cfg = spi_imx->tx_wml << MX51_ECSPI_DMA_TX_WML_OFFSET;
rxt_wml_cfg = spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET;
dma = (dma & ~MX51_ECSPI_DMA_TX_WML_MASK
& ~MX51_ECSPI_DMA_RX_WML_MASK
& ~MX51_ECSPI_DMA_RXT_WML_MASK)
| rx_wml_cfg | tx_wml_cfg | rxt_wml_cfg
|(1 << MX51_ECSPI_DMA_TEDEN_OFFSET)
|(1 << MX51_ECSPI_DMA_RXDEN_OFFSET)
|(1 << MX51_ECSPI_DMA_RXTDEN_OFFSET);
writel(dma, spi_imx->base + MX51_ECSPI_DMA);
}
return 0;
}
static int __maybe_unused mx51_ecspi_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MX51_ECSPI_STAT) & MX51_ECSPI_STAT_RR;
}
static void __maybe_unused mx51_ecspi_reset(struct spi_imx_data *spi_imx)
{
/* drain receive buffer */
while (mx51_ecspi_rx_available(spi_imx))
readl(spi_imx->base + MXC_CSPIRXDATA);
}
#define MX31_INTREG_TEEN (1 << 0)
#define MX31_INTREG_RREN (1 << 3)
#define MX31_CSPICTRL_ENABLE (1 << 0)
#define MX31_CSPICTRL_MASTER (1 << 1)
#define MX31_CSPICTRL_XCH (1 << 2)
#define MX31_CSPICTRL_POL (1 << 4)
#define MX31_CSPICTRL_PHA (1 << 5)
#define MX31_CSPICTRL_SSCTL (1 << 6)
#define MX31_CSPICTRL_SSPOL (1 << 7)
#define MX31_CSPICTRL_BC_SHIFT 8
#define MX35_CSPICTRL_BL_SHIFT 20
#define MX31_CSPICTRL_CS_SHIFT 24
#define MX35_CSPICTRL_CS_SHIFT 12
#define MX31_CSPICTRL_DR_SHIFT 16
#define MX31_CSPISTATUS 0x14
#define MX31_STATUS_RR (1 << 3)
/* These functions also work for the i.MX35, but be aware that
* the i.MX35 has a slightly different register layout for bits
* we do not use here.
*/
static void __maybe_unused mx31_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned int val = 0;
if (enable & MXC_INT_TE)
val |= MX31_INTREG_TEEN;
if (enable & MXC_INT_RR)
val |= MX31_INTREG_RREN;
writel(val, spi_imx->base + MXC_CSPIINT);
}
static void __maybe_unused mx31_trigger(struct spi_imx_data *spi_imx)
{
unsigned int reg;
reg = readl(spi_imx->base + MXC_CSPICTRL);
reg |= MX31_CSPICTRL_XCH;
writel(reg, spi_imx->base + MXC_CSPICTRL);
}
static int __maybe_unused mx31_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER;
int cs = spi_imx->chipselect[config->cs];
reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
MX31_CSPICTRL_DR_SHIFT;
if (is_imx35_cspi(spi_imx)) {
reg |= (config->bpw - 1) << MX35_CSPICTRL_BL_SHIFT;
reg |= MX31_CSPICTRL_SSCTL;
} else {
reg |= (config->bpw - 1) << MX31_CSPICTRL_BC_SHIFT;
}
if (config->mode & SPI_CPHA)
reg |= MX31_CSPICTRL_PHA;
if (config->mode & SPI_CPOL)
reg |= MX31_CSPICTRL_POL;
if (config->mode & SPI_CS_HIGH)
reg |= MX31_CSPICTRL_SSPOL;
if (cs < 0)
reg |= (cs + 32) <<
(is_imx35_cspi(spi_imx) ? MX35_CSPICTRL_CS_SHIFT :
MX31_CSPICTRL_CS_SHIFT);
writel(reg, spi_imx->base + MXC_CSPICTRL);
return 0;
}
static int __maybe_unused mx31_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR;
}
static void __maybe_unused mx31_reset(struct spi_imx_data *spi_imx)
{
/* drain receive buffer */
while (readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR)
readl(spi_imx->base + MXC_CSPIRXDATA);
}
#define MX21_INTREG_RR (1 << 4)
#define MX21_INTREG_TEEN (1 << 9)
#define MX21_INTREG_RREN (1 << 13)
#define MX21_CSPICTRL_POL (1 << 5)
#define MX21_CSPICTRL_PHA (1 << 6)
#define MX21_CSPICTRL_SSPOL (1 << 8)
#define MX21_CSPICTRL_XCH (1 << 9)
#define MX21_CSPICTRL_ENABLE (1 << 10)
#define MX21_CSPICTRL_MASTER (1 << 11)
#define MX21_CSPICTRL_DR_SHIFT 14
#define MX21_CSPICTRL_CS_SHIFT 19
static void __maybe_unused mx21_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned int val = 0;
if (enable & MXC_INT_TE)
val |= MX21_INTREG_TEEN;
if (enable & MXC_INT_RR)
val |= MX21_INTREG_RREN;
writel(val, spi_imx->base + MXC_CSPIINT);
}
static void __maybe_unused mx21_trigger(struct spi_imx_data *spi_imx)
{
unsigned int reg;
reg = readl(spi_imx->base + MXC_CSPICTRL);
reg |= MX21_CSPICTRL_XCH;
writel(reg, spi_imx->base + MXC_CSPICTRL);
}
static int __maybe_unused mx21_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
unsigned int reg = MX21_CSPICTRL_ENABLE | MX21_CSPICTRL_MASTER;
int cs = spi_imx->chipselect[config->cs];
unsigned int max = is_imx27_cspi(spi_imx) ? 16 : 18;
reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, config->speed_hz, max) <<
MX21_CSPICTRL_DR_SHIFT;
reg |= config->bpw - 1;
if (config->mode & SPI_CPHA)
reg |= MX21_CSPICTRL_PHA;
if (config->mode & SPI_CPOL)
reg |= MX21_CSPICTRL_POL;
if (config->mode & SPI_CS_HIGH)
reg |= MX21_CSPICTRL_SSPOL;
if (cs < 0)
reg |= (cs + 32) << MX21_CSPICTRL_CS_SHIFT;
writel(reg, spi_imx->base + MXC_CSPICTRL);
return 0;
}
static int __maybe_unused mx21_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MXC_CSPIINT) & MX21_INTREG_RR;
}
static void __maybe_unused mx21_reset(struct spi_imx_data *spi_imx)
{
writel(1, spi_imx->base + MXC_RESET);
}
#define MX1_INTREG_RR (1 << 3)
#define MX1_INTREG_TEEN (1 << 8)
#define MX1_INTREG_RREN (1 << 11)
#define MX1_CSPICTRL_POL (1 << 4)
#define MX1_CSPICTRL_PHA (1 << 5)
#define MX1_CSPICTRL_XCH (1 << 8)
#define MX1_CSPICTRL_ENABLE (1 << 9)
#define MX1_CSPICTRL_MASTER (1 << 10)
#define MX1_CSPICTRL_DR_SHIFT 13
static void __maybe_unused mx1_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned int val = 0;
if (enable & MXC_INT_TE)
val |= MX1_INTREG_TEEN;
if (enable & MXC_INT_RR)
val |= MX1_INTREG_RREN;
writel(val, spi_imx->base + MXC_CSPIINT);
}
static void __maybe_unused mx1_trigger(struct spi_imx_data *spi_imx)
{
unsigned int reg;
reg = readl(spi_imx->base + MXC_CSPICTRL);
reg |= MX1_CSPICTRL_XCH;
writel(reg, spi_imx->base + MXC_CSPICTRL);
}
static int __maybe_unused mx1_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
unsigned int reg = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_MASTER;
reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
MX1_CSPICTRL_DR_SHIFT;
reg |= config->bpw - 1;
if (config->mode & SPI_CPHA)
reg |= MX1_CSPICTRL_PHA;
if (config->mode & SPI_CPOL)
reg |= MX1_CSPICTRL_POL;
writel(reg, spi_imx->base + MXC_CSPICTRL);
return 0;
}
static int __maybe_unused mx1_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MXC_CSPIINT) & MX1_INTREG_RR;
}
static void __maybe_unused mx1_reset(struct spi_imx_data *spi_imx)
{
writel(1, spi_imx->base + MXC_RESET);
}
static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
.intctrl = mx1_intctrl,
.config = mx1_config,
.trigger = mx1_trigger,
.rx_available = mx1_rx_available,
.reset = mx1_reset,
.devtype = IMX1_CSPI,
};
static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
.intctrl = mx21_intctrl,
.config = mx21_config,
.trigger = mx21_trigger,
.rx_available = mx21_rx_available,
.reset = mx21_reset,
.devtype = IMX21_CSPI,
};
static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
/* i.mx27 cspi shares the functions with i.mx21 one */
.intctrl = mx21_intctrl,
.config = mx21_config,
.trigger = mx21_trigger,
.rx_available = mx21_rx_available,
.reset = mx21_reset,
.devtype = IMX27_CSPI,
};
static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
.intctrl = mx31_intctrl,
.config = mx31_config,
.trigger = mx31_trigger,
.rx_available = mx31_rx_available,
.reset = mx31_reset,
.devtype = IMX31_CSPI,
};
static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
/* i.mx35 and later cspi shares the functions with i.mx31 one */
.intctrl = mx31_intctrl,
.config = mx31_config,
.trigger = mx31_trigger,
.rx_available = mx31_rx_available,
.reset = mx31_reset,
.devtype = IMX35_CSPI,
};
static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
.intctrl = mx51_ecspi_intctrl,
.config = mx51_ecspi_config,
.trigger = mx51_ecspi_trigger,
.rx_available = mx51_ecspi_rx_available,
.reset = mx51_ecspi_reset,
.devtype = IMX51_ECSPI,
};
static struct platform_device_id spi_imx_devtype[] = {
{
.name = "imx1-cspi",
.driver_data = (kernel_ulong_t) &imx1_cspi_devtype_data,
}, {
.name = "imx21-cspi",
.driver_data = (kernel_ulong_t) &imx21_cspi_devtype_data,
}, {
.name = "imx27-cspi",
.driver_data = (kernel_ulong_t) &imx27_cspi_devtype_data,
}, {
.name = "imx31-cspi",
.driver_data = (kernel_ulong_t) &imx31_cspi_devtype_data,
}, {
.name = "imx35-cspi",
.driver_data = (kernel_ulong_t) &imx35_cspi_devtype_data,
}, {
.name = "imx51-ecspi",
.driver_data = (kernel_ulong_t) &imx51_ecspi_devtype_data,
}, {
/* sentinel */
}
};
static const struct of_device_id spi_imx_dt_ids[] = {
{ .compatible = "fsl,imx1-cspi", .data = &imx1_cspi_devtype_data, },
{ .compatible = "fsl,imx21-cspi", .data = &imx21_cspi_devtype_data, },
{ .compatible = "fsl,imx27-cspi", .data = &imx27_cspi_devtype_data, },
{ .compatible = "fsl,imx31-cspi", .data = &imx31_cspi_devtype_data, },
{ .compatible = "fsl,imx35-cspi", .data = &imx35_cspi_devtype_data, },
{ .compatible = "fsl,imx51-ecspi", .data = &imx51_ecspi_devtype_data, },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, spi_imx_dt_ids);
static void spi_imx_chipselect(struct spi_device *spi, int is_active)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
int gpio = spi_imx->chipselect[spi->chip_select];
int active = is_active != BITBANG_CS_INACTIVE;
int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH);
if (!gpio_is_valid(gpio))
return;
gpio_set_value(gpio, dev_is_lowactive ^ active);
}
static void spi_imx_push(struct spi_imx_data *spi_imx)
{
while (spi_imx->txfifo < spi_imx_get_fifosize(spi_imx)) {
if (!spi_imx->count)
break;
spi_imx->tx(spi_imx);
spi_imx->txfifo++;
}
spi_imx->devtype_data->trigger(spi_imx);
}
static irqreturn_t spi_imx_isr(int irq, void *dev_id)
{
struct spi_imx_data *spi_imx = dev_id;
while (spi_imx->devtype_data->rx_available(spi_imx)) {
spi_imx->rx(spi_imx);
spi_imx->txfifo--;
}
if (spi_imx->count) {
spi_imx_push(spi_imx);
return IRQ_HANDLED;
}
if (spi_imx->txfifo) {
/* No data left to push, but still waiting for rx data,
* enable receive data available interrupt.
*/
spi_imx->devtype_data->intctrl(
spi_imx, MXC_INT_RR);
return IRQ_HANDLED;
}
spi_imx->devtype_data->intctrl(spi_imx, 0);
complete(&spi_imx->xfer_done);
return IRQ_HANDLED;
}
static int spi_imx_setupxfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
struct spi_imx_config config;
config.bpw = t ? t->bits_per_word : spi->bits_per_word;
config.speed_hz = t ? t->speed_hz : spi->max_speed_hz;
config.mode = spi->mode;
config.cs = spi->chip_select;
if (!config.speed_hz)
config.speed_hz = spi->max_speed_hz;
if (!config.bpw)
config.bpw = spi->bits_per_word;
/* Initialize the functions for transfer */
if (config.bpw <= 8) {
spi_imx->rx = spi_imx_buf_rx_u8;
spi_imx->tx = spi_imx_buf_tx_u8;
} else if (config.bpw <= 16) {
spi_imx->rx = spi_imx_buf_rx_u16;
spi_imx->tx = spi_imx_buf_tx_u16;
} else {
spi_imx->rx = spi_imx_buf_rx_u32;
spi_imx->tx = spi_imx_buf_tx_u32;
}
spi_imx->devtype_data->config(spi_imx, &config);
return 0;
}
static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx)
{
struct spi_master *master = spi_imx->bitbang.master;
if (master->dma_rx) {
dma_release_channel(master->dma_rx);
master->dma_rx = NULL;
}
if (master->dma_tx) {
dma_release_channel(master->dma_tx);
master->dma_tx = NULL;
}
spi_imx->dma_is_inited = 0;
}
static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
struct spi_master *master,
const struct resource *res)
{
struct dma_slave_config slave_config = {};
int ret;
/* Prepare for TX DMA: */
master->dma_tx = dma_request_slave_channel(dev, "tx");
if (!master->dma_tx) {
dev_err(dev, "cannot get the TX DMA channel!\n");
ret = -EINVAL;
goto err;
}
slave_config.direction = DMA_MEM_TO_DEV;
slave_config.dst_addr = res->start + MXC_CSPITXDATA;
slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
slave_config.dst_maxburst = spi_imx_get_fifosize(spi_imx) / 2;
ret = dmaengine_slave_config(master->dma_tx, &slave_config);
if (ret) {
dev_err(dev, "error in TX dma configuration.\n");
goto err;
}
/* Prepare for RX : */
master->dma_rx = dma_request_slave_channel(dev, "rx");
if (!master->dma_rx) {
dev_dbg(dev, "cannot get the DMA channel.\n");
ret = -EINVAL;
goto err;
}
slave_config.direction = DMA_DEV_TO_MEM;
slave_config.src_addr = res->start + MXC_CSPIRXDATA;
slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
slave_config.src_maxburst = spi_imx_get_fifosize(spi_imx) / 2;
ret = dmaengine_slave_config(master->dma_rx, &slave_config);
if (ret) {
dev_err(dev, "error in RX dma configuration.\n");
goto err;
}
init_completion(&spi_imx->dma_rx_completion);
init_completion(&spi_imx->dma_tx_completion);
master->can_dma = spi_imx_can_dma;
master->max_dma_len = MAX_SDMA_BD_BYTES;
spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX |
SPI_MASTER_MUST_TX;
spi_imx->dma_is_inited = 1;
return 0;
err:
spi_imx_sdma_exit(spi_imx);
return ret;
}
static void spi_imx_dma_rx_callback(void *cookie)
{
struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
complete(&spi_imx->dma_rx_completion);
}
static void spi_imx_dma_tx_callback(void *cookie)
{
struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
complete(&spi_imx->dma_tx_completion);
}
static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
struct spi_transfer *transfer)
{
struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
int ret;
u32 dma;
int left;
struct spi_master *master = spi_imx->bitbang.master;
struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg;
if (tx) {
desc_tx = dmaengine_prep_slave_sg(master->dma_tx,
tx->sgl, tx->nents, DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_tx)
goto no_dma;
desc_tx->callback = spi_imx_dma_tx_callback;
desc_tx->callback_param = (void *)spi_imx;
dmaengine_submit(desc_tx);
}
if (rx) {
desc_rx = dmaengine_prep_slave_sg(master->dma_rx,
rx->sgl, rx->nents, DMA_FROM_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_rx)
goto no_dma;
desc_rx->callback = spi_imx_dma_rx_callback;
desc_rx->callback_param = (void *)spi_imx;
dmaengine_submit(desc_rx);
}
reinit_completion(&spi_imx->dma_rx_completion);
reinit_completion(&spi_imx->dma_tx_completion);
/* Trigger the cspi module. */
spi_imx->dma_finished = 0;
dma = readl(spi_imx->base + MX51_ECSPI_DMA);
dma = dma & (~MX51_ECSPI_DMA_RXT_WML_MASK);
/* Change RX_DMA_LENGTH trigger dma fetch tail data */
left = transfer->len % spi_imx->rxt_wml;
if (left)
writel(dma | (left << MX51_ECSPI_DMA_RXT_WML_OFFSET),
spi_imx->base + MX51_ECSPI_DMA);
spi_imx->devtype_data->trigger(spi_imx);
dma_async_issue_pending(master->dma_tx);
dma_async_issue_pending(master->dma_rx);
/* Wait SDMA to finish the data transfer.*/
ret = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
IMX_DMA_TIMEOUT);
if (!ret) {
pr_warn("%s %s: I/O Error in DMA TX\n",
dev_driver_string(&master->dev),
dev_name(&master->dev));
dmaengine_terminate_all(master->dma_tx);
} else {
ret = wait_for_completion_timeout(&spi_imx->dma_rx_completion,
IMX_DMA_TIMEOUT);
if (!ret) {
pr_warn("%s %s: I/O Error in DMA RX\n",
dev_driver_string(&master->dev),
dev_name(&master->dev));
spi_imx->devtype_data->reset(spi_imx);
dmaengine_terminate_all(master->dma_rx);
}
writel(dma |
spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET,
spi_imx->base + MX51_ECSPI_DMA);
}
spi_imx->dma_finished = 1;
spi_imx->devtype_data->trigger(spi_imx);
if (!ret)
ret = -ETIMEDOUT;
else if (ret > 0)
ret = transfer->len;
return ret;
no_dma:
pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
dev_driver_string(&master->dev),
dev_name(&master->dev));
return -EAGAIN;
}
static int spi_imx_pio_transfer(struct spi_device *spi,
struct spi_transfer *transfer)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
spi_imx->tx_buf = transfer->tx_buf;
spi_imx->rx_buf = transfer->rx_buf;
spi_imx->count = transfer->len;
spi_imx->txfifo = 0;
reinit_completion(&spi_imx->xfer_done);
spi_imx_push(spi_imx);
spi_imx->devtype_data->intctrl(spi_imx, MXC_INT_TE);
wait_for_completion(&spi_imx->xfer_done);
return transfer->len;
}
static int spi_imx_transfer(struct spi_device *spi,
struct spi_transfer *transfer)
{
int ret;
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
if (spi_imx->bitbang.master->can_dma &&
spi_imx_can_dma(spi_imx->bitbang.master, spi, transfer)) {
spi_imx->usedma = true;
ret = spi_imx_dma_transfer(spi_imx, transfer);
if (ret != -EAGAIN)
return ret;
}
spi_imx->usedma = false;
return spi_imx_pio_transfer(spi, transfer);
}
static int spi_imx_setup(struct spi_device *spi)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
int gpio = spi_imx->chipselect[spi->chip_select];
dev_dbg(&spi->dev, "%s: mode %d, %u bpw, %d hz\n", __func__,
spi->mode, spi->bits_per_word, spi->max_speed_hz);
if (gpio_is_valid(gpio))
gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
spi_imx_chipselect(spi, BITBANG_CS_INACTIVE);
return 0;
}
static void spi_imx_cleanup(struct spi_device *spi)
{
}
static int
spi_imx_prepare_message(struct spi_master *master, struct spi_message *msg)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
int ret;
ret = clk_enable(spi_imx->clk_per);
if (ret)
return ret;
ret = clk_enable(spi_imx->clk_ipg);
if (ret) {
clk_disable(spi_imx->clk_per);
return ret;
}
return 0;
}
static int
spi_imx_unprepare_message(struct spi_master *master, struct spi_message *msg)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
clk_disable(spi_imx->clk_ipg);
clk_disable(spi_imx->clk_per);
return 0;
}
static int spi_imx_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
const struct of_device_id *of_id =
of_match_device(spi_imx_dt_ids, &pdev->dev);
struct spi_imx_master *mxc_platform_info =
dev_get_platdata(&pdev->dev);
struct spi_master *master;
struct spi_imx_data *spi_imx;
struct resource *res;
int i, ret, num_cs;
if (!np && !mxc_platform_info) {
dev_err(&pdev->dev, "can't get the platform data\n");
return -EINVAL;
}
ret = of_property_read_u32(np, "fsl,spi-num-chipselects", &num_cs);
if (ret < 0) {
if (mxc_platform_info)
num_cs = mxc_platform_info->num_chipselect;
else
return ret;
}
master = spi_alloc_master(&pdev->dev,
sizeof(struct spi_imx_data) + sizeof(int) * num_cs);
if (!master)
return -ENOMEM;
platform_set_drvdata(pdev, master);
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
master->bus_num = pdev->id;
master->num_chipselect = num_cs;
spi_imx = spi_master_get_devdata(master);
spi_imx->bitbang.master = master;
for (i = 0; i < master->num_chipselect; i++) {
int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
if (!gpio_is_valid(cs_gpio) && mxc_platform_info)
cs_gpio = mxc_platform_info->chipselect[i];
spi_imx->chipselect[i] = cs_gpio;
if (!gpio_is_valid(cs_gpio))
continue;
ret = devm_gpio_request(&pdev->dev, spi_imx->chipselect[i],
DRIVER_NAME);
if (ret) {
dev_err(&pdev->dev, "can't get cs gpios\n");
goto out_master_put;
}
}
spi_imx->bitbang.chipselect = spi_imx_chipselect;
spi_imx->bitbang.setup_transfer = spi_imx_setupxfer;
spi_imx->bitbang.txrx_bufs = spi_imx_transfer;
spi_imx->bitbang.master->setup = spi_imx_setup;
spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
init_completion(&spi_imx->xfer_done);
spi_imx->devtype_data = of_id ? of_id->data :
(struct spi_imx_devtype_data *) pdev->id_entry->driver_data;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
spi_imx->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(spi_imx->base)) {
ret = PTR_ERR(spi_imx->base);
goto out_master_put;
}
spi_imx->irq = platform_get_irq(pdev, 0);
if (spi_imx->irq < 0) {
ret = spi_imx->irq;
goto out_master_put;
}
ret = devm_request_irq(&pdev->dev, spi_imx->irq, spi_imx_isr, 0,
dev_name(&pdev->dev), spi_imx);
if (ret) {
dev_err(&pdev->dev, "can't get irq%d: %d\n", spi_imx->irq, ret);
goto out_master_put;
}
spi_imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
if (IS_ERR(spi_imx->clk_ipg)) {
ret = PTR_ERR(spi_imx->clk_ipg);
goto out_master_put;
}
spi_imx->clk_per = devm_clk_get(&pdev->dev, "per");
if (IS_ERR(spi_imx->clk_per)) {
ret = PTR_ERR(spi_imx->clk_per);
goto out_master_put;
}
ret = clk_prepare_enable(spi_imx->clk_per);
if (ret)
goto out_master_put;
ret = clk_prepare_enable(spi_imx->clk_ipg);
if (ret)
goto out_put_per;
spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per);
/*
* Only validated on i.mx6 now, can remove the constrain if validated on
* other chips.
*/
if (spi_imx->devtype_data == &imx51_ecspi_devtype_data
&& spi_imx_sdma_init(&pdev->dev, spi_imx, master, res))
dev_err(&pdev->dev, "dma setup error,use pio instead\n");
spi_imx->devtype_data->reset(spi_imx);
spi_imx->devtype_data->intctrl(spi_imx, 0);
master->dev.of_node = pdev->dev.of_node;
ret = spi_bitbang_start(&spi_imx->bitbang);
if (ret) {
dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
goto out_clk_put;
}
dev_info(&pdev->dev, "probed\n");
clk_disable(spi_imx->clk_ipg);
clk_disable(spi_imx->clk_per);
return ret;
out_clk_put:
clk_disable_unprepare(spi_imx->clk_ipg);
out_put_per:
clk_disable_unprepare(spi_imx->clk_per);
out_master_put:
spi_master_put(master);
return ret;
}
static int spi_imx_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
spi_bitbang_stop(&spi_imx->bitbang);
writel(0, spi_imx->base + MXC_CSPICTRL);
clk_unprepare(spi_imx->clk_ipg);
clk_unprepare(spi_imx->clk_per);
spi_imx_sdma_exit(spi_imx);
spi_master_put(master);
return 0;
}
static struct platform_driver spi_imx_driver = {
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
.of_match_table = spi_imx_dt_ids,
},
.id_table = spi_imx_devtype,
.probe = spi_imx_probe,
.remove = spi_imx_remove,
};
module_platform_driver(spi_imx_driver);
MODULE_DESCRIPTION("SPI Master Controller driver");
MODULE_AUTHOR("Sascha Hauer, Pengutronix");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);