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spi-omap2-mcspi.c
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spi-omap2-mcspi.c
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/*
* OMAP2 McSPI controller driver
*
* Copyright (C) 2005, 2006 Nokia Corporation
* Author: Samuel Ortiz <[email protected]> and
* Juha Yrj�l� <[email protected]>
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/omap-dma.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/gcd.h>
#include <linux/spi/spi.h>
#include <linux/platform_data/spi-omap2-mcspi.h>
#define OMAP2_MCSPI_MAX_FREQ 48000000
#define OMAP2_MCSPI_MAX_DIVIDER 4096
#define OMAP2_MCSPI_MAX_FIFODEPTH 64
#define OMAP2_MCSPI_MAX_FIFOWCNT 0xFFFF
#define SPI_AUTOSUSPEND_TIMEOUT 2000
#define OMAP2_MCSPI_REVISION 0x00
#define OMAP2_MCSPI_SYSSTATUS 0x14
#define OMAP2_MCSPI_IRQSTATUS 0x18
#define OMAP2_MCSPI_IRQENABLE 0x1c
#define OMAP2_MCSPI_WAKEUPENABLE 0x20
#define OMAP2_MCSPI_SYST 0x24
#define OMAP2_MCSPI_MODULCTRL 0x28
#define OMAP2_MCSPI_XFERLEVEL 0x7c
/* per-channel banks, 0x14 bytes each, first is: */
#define OMAP2_MCSPI_CHCONF0 0x2c
#define OMAP2_MCSPI_CHSTAT0 0x30
#define OMAP2_MCSPI_CHCTRL0 0x34
#define OMAP2_MCSPI_TX0 0x38
#define OMAP2_MCSPI_RX0 0x3c
/* per-register bitmasks: */
#define OMAP2_MCSPI_IRQSTATUS_EOW BIT(17)
#define OMAP2_MCSPI_MODULCTRL_SINGLE BIT(0)
#define OMAP2_MCSPI_MODULCTRL_MS BIT(2)
#define OMAP2_MCSPI_MODULCTRL_STEST BIT(3)
#define OMAP2_MCSPI_CHCONF_PHA BIT(0)
#define OMAP2_MCSPI_CHCONF_POL BIT(1)
#define OMAP2_MCSPI_CHCONF_CLKD_MASK (0x0f << 2)
#define OMAP2_MCSPI_CHCONF_EPOL BIT(6)
#define OMAP2_MCSPI_CHCONF_WL_MASK (0x1f << 7)
#define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY BIT(12)
#define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY BIT(13)
#define OMAP2_MCSPI_CHCONF_TRM_MASK (0x03 << 12)
#define OMAP2_MCSPI_CHCONF_DMAW BIT(14)
#define OMAP2_MCSPI_CHCONF_DMAR BIT(15)
#define OMAP2_MCSPI_CHCONF_DPE0 BIT(16)
#define OMAP2_MCSPI_CHCONF_DPE1 BIT(17)
#define OMAP2_MCSPI_CHCONF_IS BIT(18)
#define OMAP2_MCSPI_CHCONF_TURBO BIT(19)
#define OMAP2_MCSPI_CHCONF_FORCE BIT(20)
#define OMAP2_MCSPI_CHCONF_FFET BIT(27)
#define OMAP2_MCSPI_CHCONF_FFER BIT(28)
#define OMAP2_MCSPI_CHCONF_CLKG BIT(29)
#define OMAP2_MCSPI_CHSTAT_RXS BIT(0)
#define OMAP2_MCSPI_CHSTAT_TXS BIT(1)
#define OMAP2_MCSPI_CHSTAT_EOT BIT(2)
#define OMAP2_MCSPI_CHSTAT_TXFFE BIT(3)
#define OMAP2_MCSPI_CHCTRL_EN BIT(0)
#define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK (0xff << 8)
#define OMAP2_MCSPI_WAKEUPENABLE_WKEN BIT(0)
/* We have 2 DMA channels per CS, one for RX and one for TX */
struct omap2_mcspi_dma {
struct dma_chan *dma_tx;
struct dma_chan *dma_rx;
int dma_tx_sync_dev;
int dma_rx_sync_dev;
struct completion dma_tx_completion;
struct completion dma_rx_completion;
char dma_rx_ch_name[14];
char dma_tx_ch_name[14];
};
/* use PIO for small transfers, avoiding DMA setup/teardown overhead and
* cache operations; better heuristics consider wordsize and bitrate.
*/
#define DMA_MIN_BYTES 160
/*
* Used for context save and restore, structure members to be updated whenever
* corresponding registers are modified.
*/
struct omap2_mcspi_regs {
u32 modulctrl;
u32 wakeupenable;
struct list_head cs;
};
struct omap2_mcspi {
struct spi_master *master;
/* Virtual base address of the controller */
void __iomem *base;
unsigned long phys;
/* SPI1 has 4 channels, while SPI2 has 2 */
struct omap2_mcspi_dma *dma_channels;
struct device *dev;
struct omap2_mcspi_regs ctx;
int fifo_depth;
unsigned int pin_dir:1;
};
struct omap2_mcspi_cs {
void __iomem *base;
unsigned long phys;
int word_len;
u16 mode;
struct list_head node;
/* Context save and restore shadow register */
u32 chconf0, chctrl0;
};
static inline void mcspi_write_reg(struct spi_master *master,
int idx, u32 val)
{
struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
writel_relaxed(val, mcspi->base + idx);
}
static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
{
struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
return readl_relaxed(mcspi->base + idx);
}
static inline void mcspi_write_cs_reg(const struct spi_device *spi,
int idx, u32 val)
{
struct omap2_mcspi_cs *cs = spi->controller_state;
writel_relaxed(val, cs->base + idx);
}
static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
{
struct omap2_mcspi_cs *cs = spi->controller_state;
return readl_relaxed(cs->base + idx);
}
static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
{
struct omap2_mcspi_cs *cs = spi->controller_state;
return cs->chconf0;
}
static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
{
struct omap2_mcspi_cs *cs = spi->controller_state;
cs->chconf0 = val;
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
}
static inline int mcspi_bytes_per_word(int word_len)
{
if (word_len <= 8)
return 1;
else if (word_len <= 16)
return 2;
else /* word_len <= 32 */
return 4;
}
static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
int is_read, int enable)
{
u32 l, rw;
l = mcspi_cached_chconf0(spi);
if (is_read) /* 1 is read, 0 write */
rw = OMAP2_MCSPI_CHCONF_DMAR;
else
rw = OMAP2_MCSPI_CHCONF_DMAW;
if (enable)
l |= rw;
else
l &= ~rw;
mcspi_write_chconf0(spi, l);
}
static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
{
struct omap2_mcspi_cs *cs = spi->controller_state;
u32 l;
l = cs->chctrl0;
if (enable)
l |= OMAP2_MCSPI_CHCTRL_EN;
else
l &= ~OMAP2_MCSPI_CHCTRL_EN;
cs->chctrl0 = l;
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
/* Flash post-writes */
mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
}
static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
{
u32 l;
l = mcspi_cached_chconf0(spi);
if (cs_active)
l |= OMAP2_MCSPI_CHCONF_FORCE;
else
l &= ~OMAP2_MCSPI_CHCONF_FORCE;
mcspi_write_chconf0(spi, l);
}
static void omap2_mcspi_set_master_mode(struct spi_master *master)
{
struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
struct omap2_mcspi_regs *ctx = &mcspi->ctx;
u32 l;
/*
* Setup when switching from (reset default) slave mode
* to single-channel master mode
*/
l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS);
l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
ctx->modulctrl = l;
}
static void omap2_mcspi_set_fifo(const struct spi_device *spi,
struct spi_transfer *t, int enable)
{
struct spi_master *master = spi->master;
struct omap2_mcspi_cs *cs = spi->controller_state;
struct omap2_mcspi *mcspi;
unsigned int wcnt;
int max_fifo_depth, fifo_depth, bytes_per_word;
u32 chconf, xferlevel;
mcspi = spi_master_get_devdata(master);
chconf = mcspi_cached_chconf0(spi);
if (enable) {
bytes_per_word = mcspi_bytes_per_word(cs->word_len);
if (t->len % bytes_per_word != 0)
goto disable_fifo;
if (t->rx_buf != NULL && t->tx_buf != NULL)
max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
else
max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
fifo_depth = gcd(t->len, max_fifo_depth);
if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0)
goto disable_fifo;
wcnt = t->len / bytes_per_word;
if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
goto disable_fifo;
xferlevel = wcnt << 16;
if (t->rx_buf != NULL) {
chconf |= OMAP2_MCSPI_CHCONF_FFER;
xferlevel |= (fifo_depth - 1) << 8;
}
if (t->tx_buf != NULL) {
chconf |= OMAP2_MCSPI_CHCONF_FFET;
xferlevel |= fifo_depth - 1;
}
mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel);
mcspi_write_chconf0(spi, chconf);
mcspi->fifo_depth = fifo_depth;
return;
}
disable_fifo:
if (t->rx_buf != NULL)
chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
if (t->tx_buf != NULL)
chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
mcspi_write_chconf0(spi, chconf);
mcspi->fifo_depth = 0;
}
static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
{
struct spi_master *spi_cntrl = mcspi->master;
struct omap2_mcspi_regs *ctx = &mcspi->ctx;
struct omap2_mcspi_cs *cs;
/* McSPI: context restore */
mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
list_for_each_entry(cs, &ctx->cs, node)
writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
}
static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
{
unsigned long timeout;
timeout = jiffies + msecs_to_jiffies(1000);
while (!(readl_relaxed(reg) & bit)) {
if (time_after(jiffies, timeout)) {
if (!(readl_relaxed(reg) & bit))
return -ETIMEDOUT;
else
return 0;
}
cpu_relax();
}
return 0;
}
static void omap2_mcspi_rx_callback(void *data)
{
struct spi_device *spi = data;
struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
/* We must disable the DMA RX request */
omap2_mcspi_set_dma_req(spi, 1, 0);
complete(&mcspi_dma->dma_rx_completion);
}
static void omap2_mcspi_tx_callback(void *data)
{
struct spi_device *spi = data;
struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
/* We must disable the DMA TX request */
omap2_mcspi_set_dma_req(spi, 0, 0);
complete(&mcspi_dma->dma_tx_completion);
}
static void omap2_mcspi_tx_dma(struct spi_device *spi,
struct spi_transfer *xfer,
struct dma_slave_config cfg)
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
unsigned int count;
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
count = xfer->len;
if (mcspi_dma->dma_tx) {
struct dma_async_tx_descriptor *tx;
struct scatterlist sg;
dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
sg_init_table(&sg, 1);
sg_dma_address(&sg) = xfer->tx_dma;
sg_dma_len(&sg) = xfer->len;
tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (tx) {
tx->callback = omap2_mcspi_tx_callback;
tx->callback_param = spi;
dmaengine_submit(tx);
} else {
/* FIXME: fall back to PIO? */
}
}
dma_async_issue_pending(mcspi_dma->dma_tx);
omap2_mcspi_set_dma_req(spi, 0, 1);
}
static unsigned
omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
struct dma_slave_config cfg,
unsigned es)
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
unsigned int count, dma_count;
u32 l;
int elements = 0;
int word_len, element_count;
struct omap2_mcspi_cs *cs = spi->controller_state;
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
count = xfer->len;
dma_count = xfer->len;
if (mcspi->fifo_depth == 0)
dma_count -= es;
word_len = cs->word_len;
l = mcspi_cached_chconf0(spi);
if (word_len <= 8)
element_count = count;
else if (word_len <= 16)
element_count = count >> 1;
else /* word_len <= 32 */
element_count = count >> 2;
if (mcspi_dma->dma_rx) {
struct dma_async_tx_descriptor *tx;
struct scatterlist sg;
dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
dma_count -= es;
sg_init_table(&sg, 1);
sg_dma_address(&sg) = xfer->rx_dma;
sg_dma_len(&sg) = dma_count;
tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
DMA_CTRL_ACK);
if (tx) {
tx->callback = omap2_mcspi_rx_callback;
tx->callback_param = spi;
dmaengine_submit(tx);
} else {
/* FIXME: fall back to PIO? */
}
}
dma_async_issue_pending(mcspi_dma->dma_rx);
omap2_mcspi_set_dma_req(spi, 1, 1);
wait_for_completion(&mcspi_dma->dma_rx_completion);
dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
DMA_FROM_DEVICE);
if (mcspi->fifo_depth > 0)
return count;
omap2_mcspi_set_enable(spi, 0);
elements = element_count - 1;
if (l & OMAP2_MCSPI_CHCONF_TURBO) {
elements--;
if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
& OMAP2_MCSPI_CHSTAT_RXS)) {
u32 w;
w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
if (word_len <= 8)
((u8 *)xfer->rx_buf)[elements++] = w;
else if (word_len <= 16)
((u16 *)xfer->rx_buf)[elements++] = w;
else /* word_len <= 32 */
((u32 *)xfer->rx_buf)[elements++] = w;
} else {
int bytes_per_word = mcspi_bytes_per_word(word_len);
dev_err(&spi->dev, "DMA RX penultimate word empty\n");
count -= (bytes_per_word << 1);
omap2_mcspi_set_enable(spi, 1);
return count;
}
}
if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
& OMAP2_MCSPI_CHSTAT_RXS)) {
u32 w;
w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
if (word_len <= 8)
((u8 *)xfer->rx_buf)[elements] = w;
else if (word_len <= 16)
((u16 *)xfer->rx_buf)[elements] = w;
else /* word_len <= 32 */
((u32 *)xfer->rx_buf)[elements] = w;
} else {
dev_err(&spi->dev, "DMA RX last word empty\n");
count -= mcspi_bytes_per_word(word_len);
}
omap2_mcspi_set_enable(spi, 1);
return count;
}
static unsigned
omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_cs *cs = spi->controller_state;
struct omap2_mcspi_dma *mcspi_dma;
unsigned int count;
u32 l;
u8 *rx;
const u8 *tx;
struct dma_slave_config cfg;
enum dma_slave_buswidth width;
unsigned es;
u32 burst;
void __iomem *chstat_reg;
void __iomem *irqstat_reg;
int wait_res;
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
l = mcspi_cached_chconf0(spi);
if (cs->word_len <= 8) {
width = DMA_SLAVE_BUSWIDTH_1_BYTE;
es = 1;
} else if (cs->word_len <= 16) {
width = DMA_SLAVE_BUSWIDTH_2_BYTES;
es = 2;
} else {
width = DMA_SLAVE_BUSWIDTH_4_BYTES;
es = 4;
}
count = xfer->len;
burst = 1;
if (mcspi->fifo_depth > 0) {
if (count > mcspi->fifo_depth)
burst = mcspi->fifo_depth / es;
else
burst = count / es;
}
memset(&cfg, 0, sizeof(cfg));
cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
cfg.src_addr_width = width;
cfg.dst_addr_width = width;
cfg.src_maxburst = burst;
cfg.dst_maxburst = burst;
rx = xfer->rx_buf;
tx = xfer->tx_buf;
if (tx != NULL)
omap2_mcspi_tx_dma(spi, xfer, cfg);
if (rx != NULL)
count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
if (tx != NULL) {
wait_for_completion(&mcspi_dma->dma_tx_completion);
dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
DMA_TO_DEVICE);
if (mcspi->fifo_depth > 0) {
irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
if (mcspi_wait_for_reg_bit(irqstat_reg,
OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
dev_err(&spi->dev, "EOW timed out\n");
mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
OMAP2_MCSPI_IRQSTATUS_EOW);
}
/* for TX_ONLY mode, be sure all words have shifted out */
if (rx == NULL) {
chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
if (mcspi->fifo_depth > 0) {
wait_res = mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXFFE);
if (wait_res < 0)
dev_err(&spi->dev, "TXFFE timed out\n");
} else {
wait_res = mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXS);
if (wait_res < 0)
dev_err(&spi->dev, "TXS timed out\n");
}
if (wait_res >= 0 &&
(mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_EOT) < 0))
dev_err(&spi->dev, "EOT timed out\n");
}
}
return count;
}
static unsigned
omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_cs *cs = spi->controller_state;
unsigned int count, c;
u32 l;
void __iomem *base = cs->base;
void __iomem *tx_reg;
void __iomem *rx_reg;
void __iomem *chstat_reg;
int word_len;
mcspi = spi_master_get_devdata(spi->master);
count = xfer->len;
c = count;
word_len = cs->word_len;
l = mcspi_cached_chconf0(spi);
/* We store the pre-calculated register addresses on stack to speed
* up the transfer loop. */
tx_reg = base + OMAP2_MCSPI_TX0;
rx_reg = base + OMAP2_MCSPI_RX0;
chstat_reg = base + OMAP2_MCSPI_CHSTAT0;
if (c < (word_len>>3))
return 0;
if (word_len <= 8) {
u8 *rx;
const u8 *tx;
rx = xfer->rx_buf;
tx = xfer->tx_buf;
do {
c -= 1;
if (tx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXS) < 0) {
dev_err(&spi->dev, "TXS timed out\n");
goto out;
}
dev_vdbg(&spi->dev, "write-%d %02x\n",
word_len, *tx);
writel_relaxed(*tx++, tx_reg);
}
if (rx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev, "RXS timed out\n");
goto out;
}
if (c == 1 && tx == NULL &&
(l & OMAP2_MCSPI_CHCONF_TURBO)) {
omap2_mcspi_set_enable(spi, 0);
*rx++ = readl_relaxed(rx_reg);
dev_vdbg(&spi->dev, "read-%d %02x\n",
word_len, *(rx - 1));
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev,
"RXS timed out\n");
goto out;
}
c = 0;
} else if (c == 0 && tx == NULL) {
omap2_mcspi_set_enable(spi, 0);
}
*rx++ = readl_relaxed(rx_reg);
dev_vdbg(&spi->dev, "read-%d %02x\n",
word_len, *(rx - 1));
}
} while (c);
} else if (word_len <= 16) {
u16 *rx;
const u16 *tx;
rx = xfer->rx_buf;
tx = xfer->tx_buf;
do {
c -= 2;
if (tx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXS) < 0) {
dev_err(&spi->dev, "TXS timed out\n");
goto out;
}
dev_vdbg(&spi->dev, "write-%d %04x\n",
word_len, *tx);
writel_relaxed(*tx++, tx_reg);
}
if (rx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev, "RXS timed out\n");
goto out;
}
if (c == 2 && tx == NULL &&
(l & OMAP2_MCSPI_CHCONF_TURBO)) {
omap2_mcspi_set_enable(spi, 0);
*rx++ = readl_relaxed(rx_reg);
dev_vdbg(&spi->dev, "read-%d %04x\n",
word_len, *(rx - 1));
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev,
"RXS timed out\n");
goto out;
}
c = 0;
} else if (c == 0 && tx == NULL) {
omap2_mcspi_set_enable(spi, 0);
}
*rx++ = readl_relaxed(rx_reg);
dev_vdbg(&spi->dev, "read-%d %04x\n",
word_len, *(rx - 1));
}
} while (c >= 2);
} else if (word_len <= 32) {
u32 *rx;
const u32 *tx;
rx = xfer->rx_buf;
tx = xfer->tx_buf;
do {
c -= 4;
if (tx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXS) < 0) {
dev_err(&spi->dev, "TXS timed out\n");
goto out;
}
dev_vdbg(&spi->dev, "write-%d %08x\n",
word_len, *tx);
writel_relaxed(*tx++, tx_reg);
}
if (rx != NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev, "RXS timed out\n");
goto out;
}
if (c == 4 && tx == NULL &&
(l & OMAP2_MCSPI_CHCONF_TURBO)) {
omap2_mcspi_set_enable(spi, 0);
*rx++ = readl_relaxed(rx_reg);
dev_vdbg(&spi->dev, "read-%d %08x\n",
word_len, *(rx - 1));
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_RXS) < 0) {
dev_err(&spi->dev,
"RXS timed out\n");
goto out;
}
c = 0;
} else if (c == 0 && tx == NULL) {
omap2_mcspi_set_enable(spi, 0);
}
*rx++ = readl_relaxed(rx_reg);
dev_vdbg(&spi->dev, "read-%d %08x\n",
word_len, *(rx - 1));
}
} while (c >= 4);
}
/* for TX_ONLY mode, be sure all words have shifted out */
if (xfer->rx_buf == NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXS) < 0) {
dev_err(&spi->dev, "TXS timed out\n");
} else if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_EOT) < 0)
dev_err(&spi->dev, "EOT timed out\n");
/* disable chan to purge rx datas received in TX_ONLY transfer,
* otherwise these rx datas will affect the direct following
* RX_ONLY transfer.
*/
omap2_mcspi_set_enable(spi, 0);
}
out:
omap2_mcspi_set_enable(spi, 1);
return count - c;
}
static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
{
u32 div;
for (div = 0; div < 15; div++)
if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
return div;
return 15;
}
/* called only when no transfer is active to this device */
static int omap2_mcspi_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct omap2_mcspi_cs *cs = spi->controller_state;
struct omap2_mcspi *mcspi;
struct spi_master *spi_cntrl;
u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
u8 word_len = spi->bits_per_word;
u32 speed_hz = spi->max_speed_hz;
mcspi = spi_master_get_devdata(spi->master);
spi_cntrl = mcspi->master;
if (t != NULL && t->bits_per_word)
word_len = t->bits_per_word;
cs->word_len = word_len;
if (t && t->speed_hz)
speed_hz = t->speed_hz;
speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
clkd = omap2_mcspi_calc_divisor(speed_hz);
speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
clkg = 0;
} else {
div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
clkd = (div - 1) & 0xf;
extclk = (div - 1) >> 4;
clkg = OMAP2_MCSPI_CHCONF_CLKG;
}
l = mcspi_cached_chconf0(spi);
/* standard 4-wire master mode: SCK, MOSI/out, MISO/in, nCS
* REVISIT: this controller could support SPI_3WIRE mode.
*/
if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
l &= ~OMAP2_MCSPI_CHCONF_IS;
l &= ~OMAP2_MCSPI_CHCONF_DPE1;
l |= OMAP2_MCSPI_CHCONF_DPE0;
} else {
l |= OMAP2_MCSPI_CHCONF_IS;
l |= OMAP2_MCSPI_CHCONF_DPE1;
l &= ~OMAP2_MCSPI_CHCONF_DPE0;
}
/* wordlength */
l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
l |= (word_len - 1) << 7;
/* set chipselect polarity; manage with FORCE */
if (!(spi->mode & SPI_CS_HIGH))
l |= OMAP2_MCSPI_CHCONF_EPOL; /* active-low; normal */
else
l &= ~OMAP2_MCSPI_CHCONF_EPOL;
/* set clock divisor */
l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
l |= clkd << 2;
/* set clock granularity */
l &= ~OMAP2_MCSPI_CHCONF_CLKG;
l |= clkg;
if (clkg) {
cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
cs->chctrl0 |= extclk << 8;
mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
}
/* set SPI mode 0..3 */
if (spi->mode & SPI_CPOL)
l |= OMAP2_MCSPI_CHCONF_POL;
else
l &= ~OMAP2_MCSPI_CHCONF_POL;
if (spi->mode & SPI_CPHA)
l |= OMAP2_MCSPI_CHCONF_PHA;
else
l &= ~OMAP2_MCSPI_CHCONF_PHA;
mcspi_write_chconf0(spi, l);
cs->mode = spi->mode;
dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
speed_hz,
(spi->mode & SPI_CPHA) ? "trailing" : "leading",
(spi->mode & SPI_CPOL) ? "inverted" : "normal");
return 0;
}
/*
* Note that we currently allow DMA only if we get a channel
* for both rx and tx. Otherwise we'll do PIO for both rx and tx.
*/
static int omap2_mcspi_request_dma(struct spi_device *spi)
{
struct spi_master *master = spi->master;
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
dma_cap_mask_t mask;
unsigned sig;
mcspi = spi_master_get_devdata(master);
mcspi_dma = mcspi->dma_channels + spi->chip_select;
init_completion(&mcspi_dma->dma_rx_completion);
init_completion(&mcspi_dma->dma_tx_completion);
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
sig = mcspi_dma->dma_rx_sync_dev;
mcspi_dma->dma_rx =
dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
&sig, &master->dev,
mcspi_dma->dma_rx_ch_name);
if (!mcspi_dma->dma_rx)
goto no_dma;
sig = mcspi_dma->dma_tx_sync_dev;
mcspi_dma->dma_tx =
dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
&sig, &master->dev,
mcspi_dma->dma_tx_ch_name);
if (!mcspi_dma->dma_tx) {
dma_release_channel(mcspi_dma->dma_rx);
mcspi_dma->dma_rx = NULL;
goto no_dma;
}
return 0;
no_dma:
dev_warn(&spi->dev, "not using DMA for McSPI\n");
return -EAGAIN;
}
static int omap2_mcspi_setup(struct spi_device *spi)
{
int ret;
struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
struct omap2_mcspi_regs *ctx = &mcspi->ctx;
struct omap2_mcspi_dma *mcspi_dma;
struct omap2_mcspi_cs *cs = spi->controller_state;
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
if (!cs) {
cs = kzalloc(sizeof *cs, GFP_KERNEL);
if (!cs)
return -ENOMEM;
cs->base = mcspi->base + spi->chip_select * 0x14;
cs->phys = mcspi->phys + spi->chip_select * 0x14;
cs->mode = 0;