- 根目录:
- drivers
- spi
- spi-rspi.c
/*
* SH RSPI driver
*
* Copyright (C) 2012 Renesas Solutions Corp.
*
* Based on spi-sh.c:
* Copyright (C) 2011 Renesas Solutions Corp.
*
* 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; version 2 of the License.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/sh_dma.h>
#include <linux/spi/spi.h>
#include <linux/spi/rspi.h>
#define RSPI_SPCR 0x00 /* Control Register */
#define RSPI_SSLP 0x01 /* Slave Select Polarity Register */
#define RSPI_SPPCR 0x02 /* Pin Control Register */
#define RSPI_SPSR 0x03 /* Status Register */
#define RSPI_SPDR 0x04 /* Data Register */
#define RSPI_SPSCR 0x08 /* Sequence Control Register */
#define RSPI_SPSSR 0x09 /* Sequence Status Register */
#define RSPI_SPBR 0x0a /* Bit Rate Register */
#define RSPI_SPDCR 0x0b /* Data Control Register */
#define RSPI_SPCKD 0x0c /* Clock Delay Register */
#define RSPI_SSLND 0x0d /* Slave Select Negation Delay Register */
#define RSPI_SPND 0x0e /* Next-Access Delay Register */
#define RSPI_SPCR2 0x0f /* Control Register 2 */
#define RSPI_SPCMD0 0x10 /* Command Register 0 */
#define RSPI_SPCMD1 0x12 /* Command Register 1 */
#define RSPI_SPCMD2 0x14 /* Command Register 2 */
#define RSPI_SPCMD3 0x16 /* Command Register 3 */
#define RSPI_SPCMD4 0x18 /* Command Register 4 */
#define RSPI_SPCMD5 0x1a /* Command Register 5 */
#define RSPI_SPCMD6 0x1c /* Command Register 6 */
#define RSPI_SPCMD7 0x1e /* Command Register 7 */
#define RSPI_SPBFCR 0x20 /* Buffer Control Register */
#define RSPI_SPBFDR 0x22 /* Buffer Data Count Setting Register */
/*qspi only */
#define QSPI_SPBFCR 0x18 /* Buffer Control Register */
#define QSPI_SPBDCR 0x1a /* Buffer Data Count Register */
#define QSPI_SPBMUL0 0x1c /* Transfer Data Length Multiplier Setting Register 0 */
#define QSPI_SPBMUL1 0x20 /* Transfer Data Length Multiplier Setting Register 1 */
#define QSPI_SPBMUL2 0x24 /* Transfer Data Length Multiplier Setting Register 2 */
#define QSPI_SPBMUL3 0x28 /* Transfer Data Length Multiplier Setting Register 3 */
/* SPCR - Control Register */
#define SPCR_SPRIE 0x80 /* Receive Interrupt Enable */
#define SPCR_SPE 0x40 /* Function Enable */
#define SPCR_SPTIE 0x20 /* Transmit Interrupt Enable */
#define SPCR_SPEIE 0x10 /* Error Interrupt Enable */
#define SPCR_MSTR 0x08 /* Master/Slave Mode Select */
#define SPCR_MODFEN 0x04 /* Mode Fault Error Detection Enable */
/* RSPI on SH only */
#define SPCR_TXMD 0x02 /* TX Only Mode (vs. Full Duplex) */
#define SPCR_SPMS 0x01 /* 3-wire Mode (vs. 4-wire) */
/* QSPI on R-Car M2 only */
#define SPCR_WSWAP 0x02 /* Word Swap of read-data for DMAC */
#define SPCR_BSWAP 0x01 /* Byte Swap of read-data for DMAC */
/* SSLP - Slave Select Polarity Register */
#define SSLP_SSL1P 0x02 /* SSL1 Signal Polarity Setting */
#define SSLP_SSL0P 0x01 /* SSL0 Signal Polarity Setting */
/* SPPCR - Pin Control Register */
#define SPPCR_MOIFE 0x20 /* MOSI Idle Value Fixing Enable */
#define SPPCR_MOIFV 0x10 /* MOSI Idle Fixed Value */
#define SPPCR_SPOM 0x04
#define SPPCR_SPLP2 0x02 /* Loopback Mode 2 (non-inverting) */
#define SPPCR_SPLP 0x01 /* Loopback Mode (inverting) */
#define SPPCR_IO3FV 0x04 /* Single-/Dual-SPI Mode IO3 Output Fixed Value */
#define SPPCR_IO2FV 0x04 /* Single-/Dual-SPI Mode IO2 Output Fixed Value */
/* SPSR - Status Register */
#define SPSR_SPRF 0x80 /* Receive Buffer Full Flag */
#define SPSR_TEND 0x40 /* Transmit End */
#define SPSR_SPTEF 0x20 /* Transmit Buffer Empty Flag */
#define SPSR_PERF 0x08 /* Parity Error Flag */
#define SPSR_MODF 0x04 /* Mode Fault Error Flag */
#define SPSR_IDLNF 0x02 /* RSPI Idle Flag */
#define SPSR_OVRF 0x01 /* Overrun Error Flag */
/* SPSCR - Sequence Control Register */
#define SPSCR_SPSLN_MASK 0x07 /* Sequence Length Specification */
/* SPSSR - Sequence Status Register */
#define SPSSR_SPECM_MASK 0x70 /* Command Error Mask */
#define SPSSR_SPCP_MASK 0x07 /* Command Pointer Mask */
/* SPDCR - Data Control Register */
#define SPDCR_TXDMY 0x80 /* Dummy Data Transmission Enable */
#define SPDCR_SPLW1 0x40 /* Access Width Specification (RZ) */
#define SPDCR_SPLW0 0x20 /* Access Width Specification (RZ) */
#define SPDCR_SPLLWORD (SPDCR_SPLW1 | SPDCR_SPLW0)
#define SPDCR_SPLWORD SPDCR_SPLW1
#define SPDCR_SPLBYTE SPDCR_SPLW0
#define SPDCR_SPLW 0x20 /* Access Width Specification (SH) */
#define SPDCR_SPRDTD 0x10 /* Receive Transmit Data Select */
#define SPDCR_SLSEL1 0x08
#define SPDCR_SLSEL0 0x04
#define SPDCR_SLSEL_MASK 0x0c /* SSL1 Output Select */
#define SPDCR_SPFC1 0x02
#define SPDCR_SPFC0 0x01
#define SPDCR_SPFC_MASK 0x03 /* Frame Count Setting (1-4) */
/* SPCKD - Clock Delay Register */
#define SPCKD_SCKDL_MASK 0x07 /* Clock Delay Setting (1-8) */
/* SSLND - Slave Select Negation Delay Register */
#define SSLND_SLNDL_MASK 0x07 /* SSL Negation Delay Setting (1-8) */
/* SPND - Next-Access Delay Register */
#define SPND_SPNDL_MASK 0x07 /* Next-Access Delay Setting (1-8) */
/* SPCR2 - Control Register 2 */
#define SPCR2_PTE 0x08 /* Parity Self-Test Enable */
#define SPCR2_SPIE 0x04 /* Idle Interrupt Enable */
#define SPCR2_SPOE 0x02 /* Odd Parity Enable (vs. Even) */
#define SPCR2_SPPE 0x01 /* Parity Enable */
/* SPCMDn - Command Registers */
#define SPCMD_SCKDEN 0x8000 /* Clock Delay Setting Enable */
#define SPCMD_SLNDEN 0x4000 /* SSL Negation Delay Setting Enable */
#define SPCMD_SPNDEN 0x2000 /* Next-Access Delay Enable */
#define SPCMD_LSBF 0x1000 /* LSB First */
#define SPCMD_SPB_MASK 0x0f00 /* Data Length Setting */
#define SPCMD_SPB_8_TO_16(bit) (((bit - 1) << 8) & SPCMD_SPB_MASK)
#define SPCMD_SPB_8BIT 0x0000 /* qspi only */
#define SPCMD_SPB_16BIT 0x0100
#define SPCMD_SPB_20BIT 0x0000
#define SPCMD_SPB_24BIT 0x0100
#define SPCMD_SPB_32BIT 0x0200
#define SPCMD_SSLKP 0x0080 /* SSL Signal Level Keeping */
#define SPCMD_SPIMOD_MASK 0x0060 /* SPI Operating Mode (QSPI only) */
#define SPCMD_SPIMOD1 0x0040
#define SPCMD_SPIMOD0 0x0020
#define SPCMD_SPIMOD_SINGLE 0
#define SPCMD_SPIMOD_DUAL SPCMD_SPIMOD0
#define SPCMD_SPIMOD_QUAD SPCMD_SPIMOD1
#define SPCMD_SPRW 0x0010 /* SPI Read/Write Access (Dual/Quad) */
#define SPCMD_SSLA_MASK 0x0030 /* SSL Assert Signal Setting (RSPI) */
#define SPCMD_BRDV_MASK 0x000c /* Bit Rate Division Setting */
#define SPCMD_CPOL 0x0002 /* Clock Polarity Setting */
#define SPCMD_CPHA 0x0001 /* Clock Phase Setting */
/* SPBFCR - Buffer Control Register */
#define SPBFCR_TXRST 0x80 /* Transmit Buffer Data Reset (qspi only) */
#define SPBFCR_RXRST 0x40 /* Receive Buffer Data Reset (qspi only) */
#define SPBFCR_TXTRG_MASK 0x30 /* Transmit Buffer Data Triggering Number */
#define SPBFCR_RXTRG_MASK 0x07 /* Receive Buffer Data Triggering Number */
#define DUMMY_DATA 0x00
struct rspi_data {
void __iomem *addr;
u32 max_speed_hz;
struct spi_master *master;
struct list_head queue;
struct work_struct ws;
wait_queue_head_t wait;
spinlock_t lock;
struct clk *clk;
u8 spsr;
u16 spcmd;
const struct spi_ops *ops;
/* for dmaengine */
struct dma_chan *chan_tx;
struct dma_chan *chan_rx;
int irq;
unsigned dma_width_16bit:1;
unsigned dma_callbacked:1;
};
static void rspi_write8(const struct rspi_data *rspi, u8 data, u16 offset)
{
iowrite8(data, rspi->addr + offset);
}
static void rspi_write16(const struct rspi_data *rspi, u16 data, u16 offset)
{
iowrite16(data, rspi->addr + offset);
}
static void rspi_write32(const struct rspi_data *rspi, u32 data, u16 offset)
{
iowrite32(data, rspi->addr + offset);
}
static u8 rspi_read8(const struct rspi_data *rspi, u16 offset)
{
return ioread8(rspi->addr + offset);
}
static u16 rspi_read16(const struct rspi_data *rspi, u16 offset)
{
return ioread16(rspi->addr + offset);
}
/* optional functions */
struct spi_ops {
int (*set_config_register)(const struct rspi_data *rspi,
int access_size);
int (*send_pio)(struct rspi_data *rspi, struct spi_message *mesg,
struct spi_transfer *t);
int (*receive_pio)(struct rspi_data *rspi, struct spi_message *mesg,
struct spi_transfer *t);
};
/*
* functions for RSPI
*/
static int rspi_set_config_register(const struct rspi_data *rspi,
int access_size)
{
int spbr;
/* Sets output mode(CMOS) and MOSI signal(from previous transfer) */
rspi_write8(rspi, 0x00, RSPI_SPPCR);
/* Sets transfer bit rate */
spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz) - 1;
rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
/* Sets number of frames to be used: 1 frame */
rspi_write8(rspi, 0x00, RSPI_SPDCR);
/* Sets RSPCK, SSL, next-access delay value */
rspi_write8(rspi, 0x00, RSPI_SPCKD);
rspi_write8(rspi, 0x00, RSPI_SSLND);
rspi_write8(rspi, 0x00, RSPI_SPND);
/* Sets parity, interrupt mask */
rspi_write8(rspi, 0x00, RSPI_SPCR2);
/* Sets SPCMD */
rspi_write16(rspi, SPCMD_SPB_8_TO_16(access_size) | rspi->spcmd,
RSPI_SPCMD0);
/* Sets RSPI mode */
rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
return 0;
}
/*
* functions for QSPI
*/
static int qspi_set_config_register(const struct rspi_data *rspi,
int access_size)
{
u16 spcmd;
int spbr;
/* Sets output mode(CMOS) and MOSI signal(from previous transfer) */
rspi_write8(rspi, 0x00, RSPI_SPPCR);
/* Sets transfer bit rate */
spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz);
rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
/* Sets number of frames to be used: 1 frame */
rspi_write8(rspi, 0x00, RSPI_SPDCR);
/* Sets RSPCK, SSL, next-access delay value */
rspi_write8(rspi, 0x00, RSPI_SPCKD);
rspi_write8(rspi, 0x00, RSPI_SSLND);
rspi_write8(rspi, 0x00, RSPI_SPND);
/* Data Length Setting */
if (access_size == 8)
spcmd = SPCMD_SPB_8BIT;
else if (access_size == 16)
spcmd = SPCMD_SPB_16BIT;
else
spcmd = SPCMD_SPB_32BIT;
spcmd |= SPCMD_SCKDEN | SPCMD_SLNDEN | rspi->spcmd | SPCMD_SPNDEN;
/* Resets transfer data length */
rspi_write32(rspi, 0, QSPI_SPBMUL0);
/* Resets transmit and receive buffer */
rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
/* Sets buffer to allow normal operation */
rspi_write8(rspi, 0x00, QSPI_SPBFCR);
/* Sets SPCMD */
rspi_write16(rspi, spcmd, RSPI_SPCMD0);
/* Enables SPI function in a master mode */
rspi_write8(rspi, SPCR_SPE | SPCR_MSTR, RSPI_SPCR);
return 0;
}
#define set_config_register(spi, n) spi->ops->set_config_register(spi, n)
static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
{
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
}
static void rspi_disable_irq(const struct rspi_data *rspi, u8 disable)
{
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~disable, RSPI_SPCR);
}
static int rspi_wait_for_interrupt(struct rspi_data *rspi, u8 wait_mask,
u8 enable_bit)
{
int ret;
rspi->spsr = rspi_read8(rspi, RSPI_SPSR);
rspi_enable_irq(rspi, enable_bit);
ret = wait_event_timeout(rspi->wait, rspi->spsr & wait_mask, HZ);
if (ret == 0 && !(rspi->spsr & wait_mask))
return -ETIMEDOUT;
return 0;
}
static void rspi_assert_ssl(const struct rspi_data *rspi)
{
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR);
}
static void rspi_negate_ssl(const struct rspi_data *rspi)
{
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR);
}
static int rspi_send_pio(struct rspi_data *rspi, struct spi_message *mesg,
struct spi_transfer *t)
{
int remain = t->len;
const u8 *data = t->tx_buf;
while (remain > 0) {
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_TXMD,
RSPI_SPCR);
if (rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE) < 0) {
dev_err(&rspi->master->dev,
"%s: tx empty timeout\n", __func__);
return -ETIMEDOUT;
}
rspi_write16(rspi, *data, RSPI_SPDR);
data++;
remain--;
}
/* Waiting for the last transmission */
rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
return 0;
}
static int qspi_send_pio(struct rspi_data *rspi, struct spi_message *mesg,
struct spi_transfer *t)
{
int remain = t->len;
const u8 *data = t->tx_buf;
rspi_write8(rspi, SPBFCR_TXRST, QSPI_SPBFCR);
rspi_write8(rspi, 0x00, QSPI_SPBFCR);
while (remain > 0) {
if (rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE) < 0) {
dev_err(&rspi->master->dev,
"%s: tx empty timeout\n", __func__);
return -ETIMEDOUT;
}
rspi_write8(rspi, *data++, RSPI_SPDR);
if (rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE) < 0) {
dev_err(&rspi->master->dev,
"%s: receive timeout\n", __func__);
return -ETIMEDOUT;
}
rspi_read8(rspi, RSPI_SPDR);
remain--;
}
/* Waiting for the last transmission */
rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
return 0;
}
#define send_pio(spi, mesg, t) spi->ops->send_pio(spi, mesg, t)
static void rspi_dma_complete(void *arg)
{
struct rspi_data *rspi = arg;
rspi->dma_callbacked = 1;
wake_up_interruptible(&rspi->wait);
}
static int rspi_dma_map_sg(struct scatterlist *sg, const void *buf,
unsigned len, struct dma_chan *chan,
enum dma_transfer_direction dir)
{
sg_init_table(sg, 1);
sg_set_buf(sg, buf, len);
sg_dma_len(sg) = len;
return dma_map_sg(chan->device->dev, sg, 1, dir);
}
static void rspi_dma_unmap_sg(struct scatterlist *sg, struct dma_chan *chan,
enum dma_transfer_direction dir)
{
dma_unmap_sg(chan->device->dev, sg, 1, dir);
}
static void rspi_memory_to_8bit(void *buf, const void *data, unsigned len)
{
u16 *dst = buf;
const u8 *src = data;
while (len) {
*dst++ = (u16)(*src++);
len--;
}
}
static void rspi_memory_from_8bit(void *buf, const void *data, unsigned len)
{
u8 *dst = buf;
const u16 *src = data;
while (len) {
*dst++ = (u8)*src++;
len--;
}
}
static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
{
struct scatterlist sg;
const void *buf = NULL;
struct dma_async_tx_descriptor *desc;
unsigned len;
int ret = 0;
if (rspi->dma_width_16bit) {
void *tmp;
/*
* If DMAC bus width is 16-bit, the driver allocates a dummy
* buffer. And, the driver converts original data into the
* DMAC data as the following format:
* original data: 1st byte, 2nd byte ...
* DMAC data: 1st byte, dummy, 2nd byte, dummy ...
*/
len = t->len * 2;
tmp = kmalloc(len, GFP_KERNEL);
if (!tmp)
return -ENOMEM;
rspi_memory_to_8bit(tmp, t->tx_buf, t->len);
buf = tmp;
} else {
len = t->len;
buf = t->tx_buf;
}
if (!rspi_dma_map_sg(&sg, buf, len, rspi->chan_tx, DMA_TO_DEVICE)) {
ret = -EFAULT;
goto end_nomap;
}
desc = dmaengine_prep_slave_sg(rspi->chan_tx, &sg, 1, DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
ret = -EIO;
goto end;
}
/*
* DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
* called. So, this driver disables the IRQ while DMA transfer.
*/
disable_irq(rspi->irq);
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_TXMD, RSPI_SPCR);
rspi_enable_irq(rspi, SPCR_SPTIE);
rspi->dma_callbacked = 0;
desc->callback = rspi_dma_complete;
desc->callback_param = rspi;
dmaengine_submit(desc);
dma_async_issue_pending(rspi->chan_tx);
ret = wait_event_interruptible_timeout(rspi->wait,
rspi->dma_callbacked, HZ);
if (ret > 0 && rspi->dma_callbacked)
ret = 0;
else if (!ret)
ret = -ETIMEDOUT;
rspi_disable_irq(rspi, SPCR_SPTIE);
enable_irq(rspi->irq);
end:
rspi_dma_unmap_sg(&sg, rspi->chan_tx, DMA_TO_DEVICE);
end_nomap:
if (rspi->dma_width_16bit)
kfree(buf);
return ret;
}
static void rspi_receive_init(const struct rspi_data *rspi)
{
u8 spsr;
spsr = rspi_read8(rspi, RSPI_SPSR);
if (spsr & SPSR_SPRF)
rspi_read16(rspi, RSPI_SPDR); /* dummy read */
if (spsr & SPSR_OVRF)
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
RSPI_SPSR);
}
static int rspi_receive_pio(struct rspi_data *rspi, struct spi_message *mesg,
struct spi_transfer *t)
{
int remain = t->len;
u8 *data;
rspi_receive_init(rspi);
data = t->rx_buf;
while (remain > 0) {
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_TXMD,
RSPI_SPCR);
if (rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE) < 0) {
dev_err(&rspi->master->dev,
"%s: tx empty timeout\n", __func__);
return -ETIMEDOUT;
}
/* dummy write for generate clock */
rspi_write16(rspi, DUMMY_DATA, RSPI_SPDR);
if (rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE) < 0) {
dev_err(&rspi->master->dev,
"%s: receive timeout\n", __func__);
return -ETIMEDOUT;
}
/* SPDR allows 16 or 32-bit access only */
*data = (u8)rspi_read16(rspi, RSPI_SPDR);
data++;
remain--;
}
return 0;
}
static void qspi_receive_init(const struct rspi_data *rspi)
{
u8 spsr;
spsr = rspi_read8(rspi, RSPI_SPSR);
if (spsr & SPSR_SPRF)
rspi_read8(rspi, RSPI_SPDR); /* dummy read */
rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
rspi_write8(rspi, 0x00, QSPI_SPBFCR);
}
static int qspi_receive_pio(struct rspi_data *rspi, struct spi_message *mesg,
struct spi_transfer *t)
{
int remain = t->len;
u8 *data;
qspi_receive_init(rspi);
data = t->rx_buf;
while (remain > 0) {
if (rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE) < 0) {
dev_err(&rspi->master->dev,
"%s: tx empty timeout\n", __func__);
return -ETIMEDOUT;
}
/* dummy write for generate clock */
rspi_write8(rspi, DUMMY_DATA, RSPI_SPDR);
if (rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE) < 0) {
dev_err(&rspi->master->dev,
"%s: receive timeout\n", __func__);
return -ETIMEDOUT;
}
/* SPDR allows 8, 16 or 32-bit access */
*data++ = rspi_read8(rspi, RSPI_SPDR);
remain--;
}
return 0;
}
#define receive_pio(spi, mesg, t) spi->ops->receive_pio(spi, mesg, t)
static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)
{
struct scatterlist sg, sg_dummy;
void *dummy = NULL, *rx_buf = NULL;
struct dma_async_tx_descriptor *desc, *desc_dummy;
unsigned len;
int ret = 0;
if (rspi->dma_width_16bit) {
/*
* If DMAC bus width is 16-bit, the driver allocates a dummy
* buffer. And, finally the driver converts the DMAC data into
* actual data as the following format:
* DMAC data: 1st byte, dummy, 2nd byte, dummy ...
* actual data: 1st byte, 2nd byte ...
*/
len = t->len * 2;
rx_buf = kmalloc(len, GFP_KERNEL);
if (!rx_buf)
return -ENOMEM;
} else {
len = t->len;
rx_buf = t->rx_buf;
}
/* prepare dummy transfer to generate SPI clocks */
dummy = kzalloc(len, GFP_KERNEL);
if (!dummy) {
ret = -ENOMEM;
goto end_nomap;
}
if (!rspi_dma_map_sg(&sg_dummy, dummy, len, rspi->chan_tx,
DMA_TO_DEVICE)) {
ret = -EFAULT;
goto end_nomap;
}
desc_dummy = dmaengine_prep_slave_sg(rspi->chan_tx, &sg_dummy, 1,
DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_dummy) {
ret = -EIO;
goto end_dummy_mapped;
}
/* prepare receive transfer */
if (!rspi_dma_map_sg(&sg, rx_buf, len, rspi->chan_rx,
DMA_FROM_DEVICE)) {
ret = -EFAULT;
goto end_dummy_mapped;
}
desc = dmaengine_prep_slave_sg(rspi->chan_rx, &sg, 1, DMA_FROM_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
ret = -EIO;
goto end;
}
rspi_receive_init(rspi);
/*
* DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
* called. So, this driver disables the IRQ while DMA transfer.
*/
disable_irq(rspi->irq);
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_TXMD, RSPI_SPCR);
rspi_enable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);
rspi->dma_callbacked = 0;
desc->callback = rspi_dma_complete;
desc->callback_param = rspi;
dmaengine_submit(desc);
dma_async_issue_pending(rspi->chan_rx);
desc_dummy->callback = NULL; /* No callback */
dmaengine_submit(desc_dummy);
dma_async_issue_pending(rspi->chan_tx);
ret = wait_event_interruptible_timeout(rspi->wait,
rspi->dma_callbacked, HZ);
if (ret > 0 && rspi->dma_callbacked)
ret = 0;
else if (!ret)
ret = -ETIMEDOUT;
rspi_disable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);
enable_irq(rspi->irq);
end:
rspi_dma_unmap_sg(&sg, rspi->chan_rx, DMA_FROM_DEVICE);
end_dummy_mapped:
rspi_dma_unmap_sg(&sg_dummy, rspi->chan_tx, DMA_TO_DEVICE);
end_nomap:
if (rspi->dma_width_16bit) {
if (!ret)
rspi_memory_from_8bit(t->rx_buf, rx_buf, t->len);
kfree(rx_buf);
}
kfree(dummy);
return ret;
}
static int rspi_is_dma(const struct rspi_data *rspi, struct spi_transfer *t)
{
if (t->tx_buf && rspi->chan_tx)
return 1;
/* If the module receives data by DMAC, it also needs TX DMAC */
if (t->rx_buf && rspi->chan_tx && rspi->chan_rx)
return 1;
return 0;
}
static void rspi_work(struct work_struct *work)
{
struct rspi_data *rspi = container_of(work, struct rspi_data, ws);
struct spi_message *mesg;
struct spi_transfer *t;
unsigned long flags;
int ret;
while (1) {
spin_lock_irqsave(&rspi->lock, flags);
if (list_empty(&rspi->queue)) {
spin_unlock_irqrestore(&rspi->lock, flags);
break;
}
mesg = list_entry(rspi->queue.next, struct spi_message, queue);
list_del_init(&mesg->queue);
spin_unlock_irqrestore(&rspi->lock, flags);
rspi_assert_ssl(rspi);
list_for_each_entry(t, &mesg->transfers, transfer_list) {
if (t->tx_buf) {
if (rspi_is_dma(rspi, t))
ret = rspi_send_dma(rspi, t);
else
ret = send_pio(rspi, mesg, t);
if (ret < 0)
goto error;
}
if (t->rx_buf) {
if (rspi_is_dma(rspi, t))
ret = rspi_receive_dma(rspi, t);
else
ret = receive_pio(rspi, mesg, t);
if (ret < 0)
goto error;
}
mesg->actual_length += t->len;
}
rspi_negate_ssl(rspi);
mesg->status = 0;
mesg->complete(mesg->context);
}
return;
error:
mesg->status = ret;
mesg->complete(mesg->context);
}
static int rspi_setup(struct spi_device *spi)
{
struct rspi_data *rspi = spi_master_get_devdata(spi->master);
rspi->max_speed_hz = spi->max_speed_hz;
rspi->spcmd = SPCMD_SSLKP;
if (spi->mode & SPI_CPOL)
rspi->spcmd |= SPCMD_CPOL;
if (spi->mode & SPI_CPHA)
rspi->spcmd |= SPCMD_CPHA;
set_config_register(rspi, 8);
return 0;
}
static int rspi_transfer(struct spi_device *spi, struct spi_message *mesg)
{
struct rspi_data *rspi = spi_master_get_devdata(spi->master);
unsigned long flags;
mesg->actual_length = 0;
mesg->status = -EINPROGRESS;
spin_lock_irqsave(&rspi->lock, flags);
list_add_tail(&mesg->queue, &rspi->queue);
schedule_work(&rspi->ws);
spin_unlock_irqrestore(&rspi->lock, flags);
return 0;
}
static void rspi_cleanup(struct spi_device *spi)
{
}
static irqreturn_t rspi_irq(int irq, void *_sr)
{
struct rspi_data *rspi = _sr;
u8 spsr;
irqreturn_t ret = IRQ_NONE;
u8 disable_irq = 0;
rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
if (spsr & SPSR_SPRF)
disable_irq |= SPCR_SPRIE;
if (spsr & SPSR_SPTEF)
disable_irq |= SPCR_SPTIE;
if (disable_irq) {
ret = IRQ_HANDLED;
rspi_disable_irq(rspi, disable_irq);
wake_up(&rspi->wait);
}
return ret;
}
static int rspi_request_dma(struct rspi_data *rspi,
struct platform_device *pdev)
{
const struct rspi_plat_data *rspi_pd = dev_get_platdata(&pdev->dev);
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
dma_cap_mask_t mask;
struct dma_slave_config cfg;
int ret;
if (!res || !rspi_pd)
return 0; /* The driver assumes no error. */
rspi->dma_width_16bit = rspi_pd->dma_width_16bit;
/* If the module receives data by DMAC, it also needs TX DMAC */
if (rspi_pd->dma_rx_id && rspi_pd->dma_tx_id) {
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
rspi->chan_rx = dma_request_channel(mask, shdma_chan_filter,
(void *)rspi_pd->dma_rx_id);
if (rspi->chan_rx) {
cfg.slave_id = rspi_pd->dma_rx_id;
cfg.direction = DMA_DEV_TO_MEM;
cfg.dst_addr = 0;
cfg.src_addr = res->start + RSPI_SPDR;
ret = dmaengine_slave_config(rspi->chan_rx, &cfg);
if (!ret)
dev_info(&pdev->dev, "Use DMA when rx.\n");
else
return ret;
}
}
if (rspi_pd->dma_tx_id) {
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
rspi->chan_tx = dma_request_channel(mask, shdma_chan_filter,
(void *)rspi_pd->dma_tx_id);
if (rspi->chan_tx) {
cfg.slave_id = rspi_pd->dma_tx_id;
cfg.direction = DMA_MEM_TO_DEV;
cfg.dst_addr = res->start + RSPI_SPDR;
cfg.src_addr = 0;
ret = dmaengine_slave_config(rspi->chan_tx, &cfg);
if (!ret)
dev_info(&pdev->dev, "Use DMA when tx\n");
else
return ret;
}
}
return 0;
}
static void rspi_release_dma(struct rspi_data *rspi)
{
if (rspi->chan_tx)
dma_release_channel(rspi->chan_tx);
if (rspi->chan_rx)
dma_release_channel(rspi->chan_rx);
}
static int rspi_remove(struct platform_device *pdev)
{
struct rspi_data *rspi = platform_get_drvdata(pdev);
rspi_release_dma(rspi);
clk_disable(rspi->clk);
return 0;
}
static int rspi_probe(struct platform_device *pdev)
{
struct resource *res;
struct spi_master *master;
struct rspi_data *rspi;
int ret, irq;
char clk_name[16];
const struct rspi_plat_data *rspi_pd = dev_get_platdata(&pdev->dev);
const struct spi_ops *ops;
const struct platform_device_id *id_entry = pdev->id_entry;
ops = (struct spi_ops *)id_entry->driver_data;
/* ops parameter check */
if (!ops->set_config_register) {
dev_err(&pdev->dev, "there is no set_config_register\n");
return -ENODEV;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "platform_get_irq error\n");
return -ENODEV;
}
master = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
if (master == NULL) {
dev_err(&pdev->dev, "spi_alloc_master error.\n");
return -ENOMEM;
}
rspi = spi_master_get_devdata(master);
platform_set_drvdata(pdev, rspi);
rspi->ops = ops;
rspi->master = master;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
rspi->addr = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(rspi->addr)) {
ret = PTR_ERR(rspi->addr);
goto error1;
}
snprintf(clk_name, sizeof(clk_name), "%s%d", id_entry->name, pdev->id);
rspi->clk = devm_clk_get(&pdev->dev, clk_name);
if (IS_ERR(rspi->clk)) {
dev_err(&pdev->dev, "cannot get clock\n");
ret = PTR_ERR(rspi->clk);
goto error1;
}
clk_enable(rspi->clk);
INIT_LIST_HEAD(&rspi->queue);
spin_lock_init(&rspi->lock);
INIT_WORK(&rspi->ws, rspi_work);
init_waitqueue_head(&rspi->wait);
if (rspi_pd && rspi_pd->num_chipselect)
master->num_chipselect = rspi_pd->num_chipselect;
else
master->num_chipselect = 2; /* default */
master->bus_num = pdev->id;
master->setup = rspi_setup;
master->transfer = rspi_transfer;
master->cleanup = rspi_cleanup;
master->mode_bits = SPI_CPHA | SPI_CPOL;
ret = devm_request_irq(&pdev->dev, irq, rspi_irq, 0,
dev_name(&pdev->dev), rspi);
if (ret < 0) {
dev_err(&pdev->dev, "request_irq error\n");
goto error2;
}
rspi->irq = irq;
ret = rspi_request_dma(rspi, pdev);
if (ret < 0) {
dev_err(&pdev->dev, "rspi_request_dma failed.\n");
goto error3;
}
ret = devm_spi_register_master(&pdev->dev, master);
if (ret < 0) {
dev_err(&pdev->dev, "spi_register_master error.\n");
goto error3;
}
dev_info(&pdev->dev, "probed\n");
return 0;
error3:
rspi_release_dma(rspi);
error2:
clk_disable(rspi->clk);
error1:
spi_master_put(master);
return ret;
}
static struct spi_ops rspi_ops = {
.set_config_register = rspi_set_config_register,
.send_pio = rspi_send_pio,
.receive_pio = rspi_receive_pio,
};
static struct spi_ops qspi_ops = {
.set_config_register = qspi_set_config_register,
.send_pio = qspi_send_pio,
.receive_pio = qspi_receive_pio,
};
static struct platform_device_id spi_driver_ids[] = {
{ "rspi", (kernel_ulong_t)&rspi_ops },
{ "qspi", (kernel_ulong_t)&qspi_ops },
{},
};
MODULE_DEVICE_TABLE(platform, spi_driver_ids);
static struct platform_driver rspi_driver = {
.probe = rspi_probe,
.remove = rspi_remove,
.id_table = spi_driver_ids,
.driver = {
.name = "renesas_spi",
.owner = THIS_MODULE,
},
};
module_platform_driver(rspi_driver);
MODULE_DESCRIPTION("Renesas RSPI bus driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Yoshihiro Shimoda");
MODULE_ALIAS("platform:rspi");