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linux-pinenote/drivers/spi/davinci_spi.c
Sandeep Paulraj 358934a60d spi: Add SPI master driver for DaVinci/DA8xx 
This patch adds support for a SPI master driver for the
DaVinci series of SOCs

Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Philby John <pjohn@in.mvista.com>
Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-01-20 13:49:34 -07:00

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/*
* Copyright (C) 2009 Texas Instruments.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <mach/spi.h>
#include <mach/edma.h>
#define SPI_NO_RESOURCE ((resource_size_t)-1)
#define SPI_MAX_CHIPSELECT 2
#define CS_DEFAULT 0xFF
#define SPI_BUFSIZ (SMP_CACHE_BYTES + 1)
#define DAVINCI_DMA_DATA_TYPE_S8 0x01
#define DAVINCI_DMA_DATA_TYPE_S16 0x02
#define DAVINCI_DMA_DATA_TYPE_S32 0x04
#define SPIFMT_PHASE_MASK BIT(16)
#define SPIFMT_POLARITY_MASK BIT(17)
#define SPIFMT_DISTIMER_MASK BIT(18)
#define SPIFMT_SHIFTDIR_MASK BIT(20)
#define SPIFMT_WAITENA_MASK BIT(21)
#define SPIFMT_PARITYENA_MASK BIT(22)
#define SPIFMT_ODD_PARITY_MASK BIT(23)
#define SPIFMT_WDELAY_MASK 0x3f000000u
#define SPIFMT_WDELAY_SHIFT 24
#define SPIFMT_CHARLEN_MASK 0x0000001Fu
/* SPIGCR1 */
#define SPIGCR1_SPIENA_MASK 0x01000000u
/* SPIPC0 */
#define SPIPC0_DIFUN_MASK BIT(11) /* MISO */
#define SPIPC0_DOFUN_MASK BIT(10) /* MOSI */
#define SPIPC0_CLKFUN_MASK BIT(9) /* CLK */
#define SPIPC0_SPIENA_MASK BIT(8) /* nREADY */
#define SPIPC0_EN1FUN_MASK BIT(1)
#define SPIPC0_EN0FUN_MASK BIT(0)
#define SPIINT_MASKALL 0x0101035F
#define SPI_INTLVL_1 0x000001FFu
#define SPI_INTLVL_0 0x00000000u
/* SPIDAT1 */
#define SPIDAT1_CSHOLD_SHIFT 28
#define SPIDAT1_CSNR_SHIFT 16
#define SPIGCR1_CLKMOD_MASK BIT(1)
#define SPIGCR1_MASTER_MASK BIT(0)
#define SPIGCR1_LOOPBACK_MASK BIT(16)
/* SPIBUF */
#define SPIBUF_TXFULL_MASK BIT(29)
#define SPIBUF_RXEMPTY_MASK BIT(31)
/* Error Masks */
#define SPIFLG_DLEN_ERR_MASK BIT(0)
#define SPIFLG_TIMEOUT_MASK BIT(1)
#define SPIFLG_PARERR_MASK BIT(2)
#define SPIFLG_DESYNC_MASK BIT(3)
#define SPIFLG_BITERR_MASK BIT(4)
#define SPIFLG_OVRRUN_MASK BIT(6)
#define SPIFLG_RX_INTR_MASK BIT(8)
#define SPIFLG_TX_INTR_MASK BIT(9)
#define SPIFLG_BUF_INIT_ACTIVE_MASK BIT(24)
#define SPIFLG_MASK (SPIFLG_DLEN_ERR_MASK \
| SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \
| SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \
| SPIFLG_OVRRUN_MASK | SPIFLG_RX_INTR_MASK \
| SPIFLG_TX_INTR_MASK \
| SPIFLG_BUF_INIT_ACTIVE_MASK)
#define SPIINT_DLEN_ERR_INTR BIT(0)
#define SPIINT_TIMEOUT_INTR BIT(1)
#define SPIINT_PARERR_INTR BIT(2)
#define SPIINT_DESYNC_INTR BIT(3)
#define SPIINT_BITERR_INTR BIT(4)
#define SPIINT_OVRRUN_INTR BIT(6)
#define SPIINT_RX_INTR BIT(8)
#define SPIINT_TX_INTR BIT(9)
#define SPIINT_DMA_REQ_EN BIT(16)
#define SPIINT_ENABLE_HIGHZ BIT(24)
#define SPI_T2CDELAY_SHIFT 16
#define SPI_C2TDELAY_SHIFT 24
/* SPI Controller registers */
#define SPIGCR0 0x00
#define SPIGCR1 0x04
#define SPIINT 0x08
#define SPILVL 0x0c
#define SPIFLG 0x10
#define SPIPC0 0x14
#define SPIPC1 0x18
#define SPIPC2 0x1c
#define SPIPC3 0x20
#define SPIPC4 0x24
#define SPIPC5 0x28
#define SPIPC6 0x2c
#define SPIPC7 0x30
#define SPIPC8 0x34
#define SPIDAT0 0x38
#define SPIDAT1 0x3c
#define SPIBUF 0x40
#define SPIEMU 0x44
#define SPIDELAY 0x48
#define SPIDEF 0x4c
#define SPIFMT0 0x50
#define SPIFMT1 0x54
#define SPIFMT2 0x58
#define SPIFMT3 0x5c
#define TGINTVEC0 0x60
#define TGINTVEC1 0x64
struct davinci_spi_slave {
u32 cmd_to_write;
u32 clk_ctrl_to_write;
u32 bytes_per_word;
u8 active_cs;
};
/* We have 2 DMA channels per CS, one for RX and one for TX */
struct davinci_spi_dma {
int dma_tx_channel;
int dma_rx_channel;
int dma_tx_sync_dev;
int dma_rx_sync_dev;
enum dma_event_q eventq;
struct completion dma_tx_completion;
struct completion dma_rx_completion;
};
/* SPI Controller driver's private data. */
struct davinci_spi {
struct spi_bitbang bitbang;
struct clk *clk;
u8 version;
resource_size_t pbase;
void __iomem *base;
size_t region_size;
u32 irq;
struct completion done;
const void *tx;
void *rx;
u8 *tmp_buf;
int count;
struct davinci_spi_dma *dma_channels;
struct davinci_spi_platform_data *pdata;
void (*get_rx)(u32 rx_data, struct davinci_spi *);
u32 (*get_tx)(struct davinci_spi *);
struct davinci_spi_slave slave[SPI_MAX_CHIPSELECT];
};
static unsigned use_dma;
static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *davinci_spi)
{
u8 *rx = davinci_spi->rx;
*rx++ = (u8)data;
davinci_spi->rx = rx;
}
static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *davinci_spi)
{
u16 *rx = davinci_spi->rx;
*rx++ = (u16)data;
davinci_spi->rx = rx;
}
static u32 davinci_spi_tx_buf_u8(struct davinci_spi *davinci_spi)
{
u32 data;
const u8 *tx = davinci_spi->tx;
data = *tx++;
davinci_spi->tx = tx;
return data;
}
static u32 davinci_spi_tx_buf_u16(struct davinci_spi *davinci_spi)
{
u32 data;
const u16 *tx = davinci_spi->tx;
data = *tx++;
davinci_spi->tx = tx;
return data;
}
static inline void set_io_bits(void __iomem *addr, u32 bits)
{
u32 v = ioread32(addr);
v |= bits;
iowrite32(v, addr);
}
static inline void clear_io_bits(void __iomem *addr, u32 bits)
{
u32 v = ioread32(addr);
v &= ~bits;
iowrite32(v, addr);
}
static inline void set_fmt_bits(void __iomem *addr, u32 bits, int cs_num)
{
set_io_bits(addr + SPIFMT0 + (0x4 * cs_num), bits);
}
static inline void clear_fmt_bits(void __iomem *addr, u32 bits, int cs_num)
{
clear_io_bits(addr + SPIFMT0 + (0x4 * cs_num), bits);
}
static void davinci_spi_set_dma_req(const struct spi_device *spi, int enable)
{
struct davinci_spi *davinci_spi = spi_master_get_devdata(spi->master);
if (enable)
set_io_bits(davinci_spi->base + SPIINT, SPIINT_DMA_REQ_EN);
else
clear_io_bits(davinci_spi->base + SPIINT, SPIINT_DMA_REQ_EN);
}
/*
* Interface to control the chip select signal
*/
static void davinci_spi_chipselect(struct spi_device *spi, int value)
{
struct davinci_spi *davinci_spi;
struct davinci_spi_platform_data *pdata;
u32 data1_reg_val = 0;
davinci_spi = spi_master_get_devdata(spi->master);
pdata = davinci_spi->pdata;
/*
* Board specific chip select logic decides the polarity and cs
* line for the controller
*/
if (value == BITBANG_CS_INACTIVE) {
set_io_bits(davinci_spi->base + SPIDEF, CS_DEFAULT);
data1_reg_val |= CS_DEFAULT << SPIDAT1_CSNR_SHIFT;
iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
while ((ioread32(davinci_spi->base + SPIBUF)
& SPIBUF_RXEMPTY_MASK) == 0)
cpu_relax();
}
}
/**
* davinci_spi_setup_transfer - This functions will determine transfer method
* @spi: spi device on which data transfer to be done
* @t: spi transfer in which transfer info is filled
*
* This function determines data transfer method (8/16/32 bit transfer).
* It will also set the SPI Clock Control register according to
* SPI slave device freq.
*/
static int davinci_spi_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct davinci_spi *davinci_spi;
struct davinci_spi_platform_data *pdata;
u8 bits_per_word = 0;
u32 hz = 0, prescale;
davinci_spi = spi_master_get_devdata(spi->master);
pdata = davinci_spi->pdata;
if (t) {
bits_per_word = t->bits_per_word;
hz = t->speed_hz;
}
/* if bits_per_word is not set then set it default */
if (!bits_per_word)
bits_per_word = spi->bits_per_word;
/*
* Assign function pointer to appropriate transfer method
* 8bit, 16bit or 32bit transfer
*/
if (bits_per_word <= 8 && bits_per_word >= 2) {
davinci_spi->get_rx = davinci_spi_rx_buf_u8;
davinci_spi->get_tx = davinci_spi_tx_buf_u8;
davinci_spi->slave[spi->chip_select].bytes_per_word = 1;
} else if (bits_per_word <= 16 && bits_per_word >= 2) {
davinci_spi->get_rx = davinci_spi_rx_buf_u16;
davinci_spi->get_tx = davinci_spi_tx_buf_u16;
davinci_spi->slave[spi->chip_select].bytes_per_word = 2;
} else
return -EINVAL;
if (!hz)
hz = spi->max_speed_hz;
clear_fmt_bits(davinci_spi->base, SPIFMT_CHARLEN_MASK,
spi->chip_select);
set_fmt_bits(davinci_spi->base, bits_per_word & 0x1f,
spi->chip_select);
prescale = ((clk_get_rate(davinci_spi->clk) / hz) - 1) & 0xff;
clear_fmt_bits(davinci_spi->base, 0x0000ff00, spi->chip_select);
set_fmt_bits(davinci_spi->base, prescale << 8, spi->chip_select);
return 0;
}
static void davinci_spi_dma_rx_callback(unsigned lch, u16 ch_status, void *data)
{
struct spi_device *spi = (struct spi_device *)data;
struct davinci_spi *davinci_spi;
struct davinci_spi_dma *davinci_spi_dma;
struct davinci_spi_platform_data *pdata;
davinci_spi = spi_master_get_devdata(spi->master);
davinci_spi_dma = &(davinci_spi->dma_channels[spi->chip_select]);
pdata = davinci_spi->pdata;
if (ch_status == DMA_COMPLETE)
edma_stop(davinci_spi_dma->dma_rx_channel);
else
edma_clean_channel(davinci_spi_dma->dma_rx_channel);
complete(&davinci_spi_dma->dma_rx_completion);
/* We must disable the DMA RX request */
davinci_spi_set_dma_req(spi, 0);
}
static void davinci_spi_dma_tx_callback(unsigned lch, u16 ch_status, void *data)
{
struct spi_device *spi = (struct spi_device *)data;
struct davinci_spi *davinci_spi;
struct davinci_spi_dma *davinci_spi_dma;
struct davinci_spi_platform_data *pdata;
davinci_spi = spi_master_get_devdata(spi->master);
davinci_spi_dma = &(davinci_spi->dma_channels[spi->chip_select]);
pdata = davinci_spi->pdata;
if (ch_status == DMA_COMPLETE)
edma_stop(davinci_spi_dma->dma_tx_channel);
else
edma_clean_channel(davinci_spi_dma->dma_tx_channel);
complete(&davinci_spi_dma->dma_tx_completion);
/* We must disable the DMA TX request */
davinci_spi_set_dma_req(spi, 0);
}
static int davinci_spi_request_dma(struct spi_device *spi)
{
struct davinci_spi *davinci_spi;
struct davinci_spi_dma *davinci_spi_dma;
struct davinci_spi_platform_data *pdata;
struct device *sdev;
int r;
davinci_spi = spi_master_get_devdata(spi->master);
davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
pdata = davinci_spi->pdata;
sdev = davinci_spi->bitbang.master->dev.parent;
r = edma_alloc_channel(davinci_spi_dma->dma_rx_sync_dev,
davinci_spi_dma_rx_callback, spi,
davinci_spi_dma->eventq);
if (r < 0) {
dev_dbg(sdev, "Unable to request DMA channel for SPI RX\n");
return -EAGAIN;
}
davinci_spi_dma->dma_rx_channel = r;
r = edma_alloc_channel(davinci_spi_dma->dma_tx_sync_dev,
davinci_spi_dma_tx_callback, spi,
davinci_spi_dma->eventq);
if (r < 0) {
edma_free_channel(davinci_spi_dma->dma_rx_channel);
davinci_spi_dma->dma_rx_channel = -1;
dev_dbg(sdev, "Unable to request DMA channel for SPI TX\n");
return -EAGAIN;
}
davinci_spi_dma->dma_tx_channel = r;
return 0;
}
/**
* davinci_spi_setup - This functions will set default transfer method
* @spi: spi device on which data transfer to be done
*
* This functions sets the default transfer method.
*/
static int davinci_spi_setup(struct spi_device *spi)
{
int retval;
struct davinci_spi *davinci_spi;
struct davinci_spi_dma *davinci_spi_dma;
struct device *sdev;
davinci_spi = spi_master_get_devdata(spi->master);
sdev = davinci_spi->bitbang.master->dev.parent;
/* if bits per word length is zero then set it default 8 */
if (!spi->bits_per_word)
spi->bits_per_word = 8;
davinci_spi->slave[spi->chip_select].cmd_to_write = 0;
if (use_dma && davinci_spi->dma_channels) {
davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
if ((davinci_spi_dma->dma_rx_channel == -1)
|| (davinci_spi_dma->dma_tx_channel == -1)) {
retval = davinci_spi_request_dma(spi);
if (retval < 0)
return retval;
}
}
/*
* SPI in DaVinci and DA8xx operate between
* 600 KHz and 50 MHz
*/
if (spi->max_speed_hz < 600000 || spi->max_speed_hz > 50000000) {
dev_dbg(sdev, "Operating frequency is not in acceptable "
"range\n");
return -EINVAL;
}
/*
* Set up SPIFMTn register, unique to this chipselect.
*
* NOTE: we could do all of these with one write. Also, some
* of the "version 2" features are found in chips that don't
* support all of them...
*/
if (spi->mode & SPI_LSB_FIRST)
set_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base, SPIFMT_SHIFTDIR_MASK,
spi->chip_select);
if (spi->mode & SPI_CPOL)
set_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base, SPIFMT_POLARITY_MASK,
spi->chip_select);
if (!(spi->mode & SPI_CPHA))
set_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base, SPIFMT_PHASE_MASK,
spi->chip_select);
/*
* Version 1 hardware supports two basic SPI modes:
* - Standard SPI mode uses 4 pins, with chipselect
* - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS)
* (distinct from SPI_3WIRE, with just one data wire;
* or similar variants without MOSI or without MISO)
*
* Version 2 hardware supports an optional handshaking signal,
* so it can support two more modes:
* - 5 pin SPI variant is standard SPI plus SPI_READY
* - 4 pin with enable is (SPI_READY | SPI_NO_CS)
*/
if (davinci_spi->version == SPI_VERSION_2) {
clear_fmt_bits(davinci_spi->base, SPIFMT_WDELAY_MASK,
spi->chip_select);
set_fmt_bits(davinci_spi->base,
(davinci_spi->pdata->wdelay
<< SPIFMT_WDELAY_SHIFT)
& SPIFMT_WDELAY_MASK,
spi->chip_select);
if (davinci_spi->pdata->odd_parity)
set_fmt_bits(davinci_spi->base,
SPIFMT_ODD_PARITY_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base,
SPIFMT_ODD_PARITY_MASK,
spi->chip_select);
if (davinci_spi->pdata->parity_enable)
set_fmt_bits(davinci_spi->base,
SPIFMT_PARITYENA_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base,
SPIFMT_PARITYENA_MASK,
spi->chip_select);
if (davinci_spi->pdata->wait_enable)
set_fmt_bits(davinci_spi->base,
SPIFMT_WAITENA_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base,
SPIFMT_WAITENA_MASK,
spi->chip_select);
if (davinci_spi->pdata->timer_disable)
set_fmt_bits(davinci_spi->base,
SPIFMT_DISTIMER_MASK,
spi->chip_select);
else
clear_fmt_bits(davinci_spi->base,
SPIFMT_DISTIMER_MASK,
spi->chip_select);
}
retval = davinci_spi_setup_transfer(spi, NULL);
return retval;
}
static void davinci_spi_cleanup(struct spi_device *spi)
{
struct davinci_spi *davinci_spi = spi_master_get_devdata(spi->master);
struct davinci_spi_dma *davinci_spi_dma;
davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
if (use_dma && davinci_spi->dma_channels) {
davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
if ((davinci_spi_dma->dma_rx_channel != -1)
&& (davinci_spi_dma->dma_tx_channel != -1)) {
edma_free_channel(davinci_spi_dma->dma_tx_channel);
edma_free_channel(davinci_spi_dma->dma_rx_channel);
}
}
}
static int davinci_spi_bufs_prep(struct spi_device *spi,
struct davinci_spi *davinci_spi)
{
int op_mode = 0;
/*
* REVISIT unless devices disagree about SPI_LOOP or
* SPI_READY (SPI_NO_CS only allows one device!), this
* should not need to be done before each message...
* optimize for both flags staying cleared.
*/
op_mode = SPIPC0_DIFUN_MASK
| SPIPC0_DOFUN_MASK
| SPIPC0_CLKFUN_MASK;
if (!(spi->mode & SPI_NO_CS))
op_mode |= 1 << spi->chip_select;
if (spi->mode & SPI_READY)
op_mode |= SPIPC0_SPIENA_MASK;
iowrite32(op_mode, davinci_spi->base + SPIPC0);
if (spi->mode & SPI_LOOP)
set_io_bits(davinci_spi->base + SPIGCR1,
SPIGCR1_LOOPBACK_MASK);
else
clear_io_bits(davinci_spi->base + SPIGCR1,
SPIGCR1_LOOPBACK_MASK);
return 0;
}
static int davinci_spi_check_error(struct davinci_spi *davinci_spi,
int int_status)
{
struct device *sdev = davinci_spi->bitbang.master->dev.parent;
if (int_status & SPIFLG_TIMEOUT_MASK) {
dev_dbg(sdev, "SPI Time-out Error\n");
return -ETIMEDOUT;
}
if (int_status & SPIFLG_DESYNC_MASK) {
dev_dbg(sdev, "SPI Desynchronization Error\n");
return -EIO;
}
if (int_status & SPIFLG_BITERR_MASK) {
dev_dbg(sdev, "SPI Bit error\n");
return -EIO;
}
if (davinci_spi->version == SPI_VERSION_2) {
if (int_status & SPIFLG_DLEN_ERR_MASK) {
dev_dbg(sdev, "SPI Data Length Error\n");
return -EIO;
}
if (int_status & SPIFLG_PARERR_MASK) {
dev_dbg(sdev, "SPI Parity Error\n");
return -EIO;
}
if (int_status & SPIFLG_OVRRUN_MASK) {
dev_dbg(sdev, "SPI Data Overrun error\n");
return -EIO;
}
if (int_status & SPIFLG_TX_INTR_MASK) {
dev_dbg(sdev, "SPI TX intr bit set\n");
return -EIO;
}
if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) {
dev_dbg(sdev, "SPI Buffer Init Active\n");
return -EBUSY;
}
}
return 0;
}
/**
* davinci_spi_bufs - functions which will handle transfer data
* @spi: spi device on which data transfer to be done
* @t: spi transfer in which transfer info is filled
*
* This function will put data to be transferred into data register
* of SPI controller and then wait until the completion will be marked
* by the IRQ Handler.
*/
static int davinci_spi_bufs_pio(struct spi_device *spi, struct spi_transfer *t)
{
struct davinci_spi *davinci_spi;
int int_status, count, ret;
u8 conv, tmp;
u32 tx_data, data1_reg_val;
u32 buf_val, flg_val;
struct davinci_spi_platform_data *pdata;
davinci_spi = spi_master_get_devdata(spi->master);
pdata = davinci_spi->pdata;
davinci_spi->tx = t->tx_buf;
davinci_spi->rx = t->rx_buf;
/* convert len to words based on bits_per_word */
conv = davinci_spi->slave[spi->chip_select].bytes_per_word;
davinci_spi->count = t->len / conv;
INIT_COMPLETION(davinci_spi->done);
ret = davinci_spi_bufs_prep(spi, davinci_spi);
if (ret)
return ret;
/* Enable SPI */
set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
iowrite32(0 | (pdata->c2tdelay << SPI_C2TDELAY_SHIFT) |
(pdata->t2cdelay << SPI_T2CDELAY_SHIFT),
davinci_spi->base + SPIDELAY);
count = davinci_spi->count;
data1_reg_val = pdata->cs_hold << SPIDAT1_CSHOLD_SHIFT;
tmp = ~(0x1 << spi->chip_select);
clear_io_bits(davinci_spi->base + SPIDEF, ~tmp);
data1_reg_val |= tmp << SPIDAT1_CSNR_SHIFT;
while ((ioread32(davinci_spi->base + SPIBUF)
& SPIBUF_RXEMPTY_MASK) == 0)
cpu_relax();
/* Determine the command to execute READ or WRITE */
if (t->tx_buf) {
clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL);
while (1) {
tx_data = davinci_spi->get_tx(davinci_spi);
data1_reg_val &= ~(0xFFFF);
data1_reg_val |= (0xFFFF & tx_data);
buf_val = ioread32(davinci_spi->base + SPIBUF);
if ((buf_val & SPIBUF_TXFULL_MASK) == 0) {
iowrite32(data1_reg_val,
davinci_spi->base + SPIDAT1);
count--;
}
while (ioread32(davinci_spi->base + SPIBUF)
& SPIBUF_RXEMPTY_MASK)
cpu_relax();
/* getting the returned byte */
if (t->rx_buf) {
buf_val = ioread32(davinci_spi->base + SPIBUF);
davinci_spi->get_rx(buf_val, davinci_spi);
}
if (count <= 0)
break;
}
} else {
if (pdata->poll_mode) {
while (1) {
/* keeps the serial clock going */
if ((ioread32(davinci_spi->base + SPIBUF)
& SPIBUF_TXFULL_MASK) == 0)
iowrite32(data1_reg_val,
davinci_spi->base + SPIDAT1);
while (ioread32(davinci_spi->base + SPIBUF) &
SPIBUF_RXEMPTY_MASK)
cpu_relax();
flg_val = ioread32(davinci_spi->base + SPIFLG);
buf_val = ioread32(davinci_spi->base + SPIBUF);
davinci_spi->get_rx(buf_val, davinci_spi);
count--;
if (count <= 0)
break;
}
} else { /* Receive in Interrupt mode */
int i;
for (i = 0; i < davinci_spi->count; i++) {
set_io_bits(davinci_spi->base + SPIINT,
SPIINT_BITERR_INTR
| SPIINT_OVRRUN_INTR
| SPIINT_RX_INTR);
iowrite32(data1_reg_val,
davinci_spi->base + SPIDAT1);
while (ioread32(davinci_spi->base + SPIINT) &
SPIINT_RX_INTR)
cpu_relax();
}
iowrite32((data1_reg_val & 0x0ffcffff),
davinci_spi->base + SPIDAT1);
}
}
/*
* Check for bit error, desync error,parity error,timeout error and
* receive overflow errors
*/
int_status = ioread32(davinci_spi->base + SPIFLG);
ret = davinci_spi_check_error(davinci_spi, int_status);
if (ret != 0)
return ret;
/* SPI Framework maintains the count only in bytes so convert back */
davinci_spi->count *= conv;
return t->len;
}
#define DAVINCI_DMA_DATA_TYPE_S8 0x01
#define DAVINCI_DMA_DATA_TYPE_S16 0x02
#define DAVINCI_DMA_DATA_TYPE_S32 0x04
static int davinci_spi_bufs_dma(struct spi_device *spi, struct spi_transfer *t)
{
struct davinci_spi *davinci_spi;
int int_status = 0;
int count, temp_count;
u8 conv = 1;
u8 tmp;
u32 data1_reg_val;
struct davinci_spi_dma *davinci_spi_dma;
int word_len, data_type, ret;
unsigned long tx_reg, rx_reg;
struct davinci_spi_platform_data *pdata;
struct device *sdev;
davinci_spi = spi_master_get_devdata(spi->master);
pdata = davinci_spi->pdata;
sdev = davinci_spi->bitbang.master->dev.parent;
davinci_spi_dma = &davinci_spi->dma_channels[spi->chip_select];
tx_reg = (unsigned long)davinci_spi->pbase + SPIDAT1;
rx_reg = (unsigned long)davinci_spi->pbase + SPIBUF;
davinci_spi->tx = t->tx_buf;
davinci_spi->rx = t->rx_buf;
/* convert len to words based on bits_per_word */
conv = davinci_spi->slave[spi->chip_select].bytes_per_word;
davinci_spi->count = t->len / conv;
INIT_COMPLETION(davinci_spi->done);
init_completion(&davinci_spi_dma->dma_rx_completion);
init_completion(&davinci_spi_dma->dma_tx_completion);
word_len = conv * 8;
if (word_len <= 8)
data_type = DAVINCI_DMA_DATA_TYPE_S8;
else if (word_len <= 16)
data_type = DAVINCI_DMA_DATA_TYPE_S16;
else if (word_len <= 32)
data_type = DAVINCI_DMA_DATA_TYPE_S32;
else
return -EINVAL;
ret = davinci_spi_bufs_prep(spi, davinci_spi);
if (ret)
return ret;
/* Put delay val if required */
iowrite32(0 | (pdata->c2tdelay << SPI_C2TDELAY_SHIFT) |
(pdata->t2cdelay << SPI_T2CDELAY_SHIFT),
davinci_spi->base + SPIDELAY);
count = davinci_spi->count; /* the number of elements */
data1_reg_val = pdata->cs_hold << SPIDAT1_CSHOLD_SHIFT;
/* CS default = 0xFF */
tmp = ~(0x1 << spi->chip_select);
clear_io_bits(davinci_spi->base + SPIDEF, ~tmp);
data1_reg_val |= tmp << SPIDAT1_CSNR_SHIFT;
/* disable all interrupts for dma transfers */
clear_io_bits(davinci_spi->base + SPIINT, SPIINT_MASKALL);
/* Disable SPI to write configuration bits in SPIDAT */
clear_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
/* Enable SPI */
set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
while ((ioread32(davinci_spi->base + SPIBUF)
& SPIBUF_RXEMPTY_MASK) == 0)
cpu_relax();
if (t->tx_buf) {
t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf, count,
DMA_TO_DEVICE);
if (dma_mapping_error(&spi->dev, t->tx_dma)) {
dev_dbg(sdev, "Unable to DMA map a %d bytes"
" TX buffer\n", count);
return -ENOMEM;
}
temp_count = count;
} else {
/* We need TX clocking for RX transaction */
t->tx_dma = dma_map_single(&spi->dev,
(void *)davinci_spi->tmp_buf, count + 1,
DMA_TO_DEVICE);
if (dma_mapping_error(&spi->dev, t->tx_dma)) {
dev_dbg(sdev, "Unable to DMA map a %d bytes"
" TX tmp buffer\n", count);
return -ENOMEM;
}
temp_count = count + 1;
}
edma_set_transfer_params(davinci_spi_dma->dma_tx_channel,
data_type, temp_count, 1, 0, ASYNC);
edma_set_dest(davinci_spi_dma->dma_tx_channel, tx_reg, INCR, W8BIT);
edma_set_src(davinci_spi_dma->dma_tx_channel, t->tx_dma, INCR, W8BIT);
edma_set_src_index(davinci_spi_dma->dma_tx_channel, data_type, 0);
edma_set_dest_index(davinci_spi_dma->dma_tx_channel, 0, 0);
if (t->rx_buf) {
/* initiate transaction */
iowrite32(data1_reg_val, davinci_spi->base + SPIDAT1);
t->rx_dma = dma_map_single(&spi->dev, (void *)t->rx_buf, count,
DMA_FROM_DEVICE);
if (dma_mapping_error(&spi->dev, t->rx_dma)) {
dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n",
count);
if (t->tx_buf != NULL)
dma_unmap_single(NULL, t->tx_dma,
count, DMA_TO_DEVICE);
return -ENOMEM;
}
edma_set_transfer_params(davinci_spi_dma->dma_rx_channel,
data_type, count, 1, 0, ASYNC);
edma_set_src(davinci_spi_dma->dma_rx_channel,
rx_reg, INCR, W8BIT);
edma_set_dest(davinci_spi_dma->dma_rx_channel,
t->rx_dma, INCR, W8BIT);
edma_set_src_index(davinci_spi_dma->dma_rx_channel, 0, 0);
edma_set_dest_index(davinci_spi_dma->dma_rx_channel,
data_type, 0);
}
if ((t->tx_buf) || (t->rx_buf))
edma_start(davinci_spi_dma->dma_tx_channel);
if (t->rx_buf)
edma_start(davinci_spi_dma->dma_rx_channel);
if ((t->rx_buf) || (t->tx_buf))
davinci_spi_set_dma_req(spi, 1);
if (t->tx_buf)
wait_for_completion_interruptible(
&davinci_spi_dma->dma_tx_completion);
if (t->rx_buf)
wait_for_completion_interruptible(
&davinci_spi_dma->dma_rx_completion);
dma_unmap_single(NULL, t->tx_dma, temp_count, DMA_TO_DEVICE);
if (t->rx_buf)
dma_unmap_single(NULL, t->rx_dma, count, DMA_FROM_DEVICE);
/*
* Check for bit error, desync error,parity error,timeout error and
* receive overflow errors
*/
int_status = ioread32(davinci_spi->base + SPIFLG);
ret = davinci_spi_check_error(davinci_spi, int_status);
if (ret != 0)
return ret;
/* SPI Framework maintains the count only in bytes so convert back */
davinci_spi->count *= conv;
return t->len;
}
/**
* davinci_spi_irq - IRQ handler for DaVinci SPI
* @irq: IRQ number for this SPI Master
* @context_data: structure for SPI Master controller davinci_spi
*/
static irqreturn_t davinci_spi_irq(s32 irq, void *context_data)
{
struct davinci_spi *davinci_spi = context_data;
u32 int_status, rx_data = 0;
irqreturn_t ret = IRQ_NONE;
int_status = ioread32(davinci_spi->base + SPIFLG);
while ((int_status & SPIFLG_RX_INTR_MASK)) {
if (likely(int_status & SPIFLG_RX_INTR_MASK)) {
ret = IRQ_HANDLED;
rx_data = ioread32(davinci_spi->base + SPIBUF);
davinci_spi->get_rx(rx_data, davinci_spi);
/* Disable Receive Interrupt */
iowrite32(~(SPIINT_RX_INTR | SPIINT_TX_INTR),
davinci_spi->base + SPIINT);
} else
(void)davinci_spi_check_error(davinci_spi, int_status);
int_status = ioread32(davinci_spi->base + SPIFLG);
}
return ret;
}
/**
* davinci_spi_probe - probe function for SPI Master Controller
* @pdev: platform_device structure which contains plateform specific data
*/
static int davinci_spi_probe(struct platform_device *pdev)
{
struct spi_master *master;
struct davinci_spi *davinci_spi;
struct davinci_spi_platform_data *pdata;
struct resource *r, *mem;
resource_size_t dma_rx_chan = SPI_NO_RESOURCE;
resource_size_t dma_tx_chan = SPI_NO_RESOURCE;
resource_size_t dma_eventq = SPI_NO_RESOURCE;
int i = 0, ret = 0;
pdata = pdev->dev.platform_data;
if (pdata == NULL) {
ret = -ENODEV;
goto err;
}
master = spi_alloc_master(&pdev->dev, sizeof(struct davinci_spi));
if (master == NULL) {
ret = -ENOMEM;
goto err;
}
dev_set_drvdata(&pdev->dev, master);
davinci_spi = spi_master_get_devdata(master);
if (davinci_spi == NULL) {
ret = -ENOENT;
goto free_master;
}
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (r == NULL) {
ret = -ENOENT;
goto free_master;
}
davinci_spi->pbase = r->start;
davinci_spi->region_size = resource_size(r);
davinci_spi->pdata = pdata;
mem = request_mem_region(r->start, davinci_spi->region_size,
pdev->name);
if (mem == NULL) {
ret = -EBUSY;
goto free_master;
}
davinci_spi->base = (struct davinci_spi_reg __iomem *)
ioremap(r->start, davinci_spi->region_size);
if (davinci_spi->base == NULL) {
ret = -ENOMEM;
goto release_region;
}
davinci_spi->irq = platform_get_irq(pdev, 0);
if (davinci_spi->irq <= 0) {
ret = -EINVAL;
goto unmap_io;
}
ret = request_irq(davinci_spi->irq, davinci_spi_irq, IRQF_DISABLED,
dev_name(&pdev->dev), davinci_spi);
if (ret)
goto unmap_io;
/* Allocate tmp_buf for tx_buf */
davinci_spi->tmp_buf = kzalloc(SPI_BUFSIZ, GFP_KERNEL);
if (davinci_spi->tmp_buf == NULL) {
ret = -ENOMEM;
goto irq_free;
}
davinci_spi->bitbang.master = spi_master_get(master);
if (davinci_spi->bitbang.master == NULL) {
ret = -ENODEV;
goto free_tmp_buf;
}
davinci_spi->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(davinci_spi->clk)) {
ret = -ENODEV;
goto put_master;
}
clk_enable(davinci_spi->clk);
master->bus_num = pdev->id;
master->num_chipselect = pdata->num_chipselect;
master->setup = davinci_spi_setup;
master->cleanup = davinci_spi_cleanup;
davinci_spi->bitbang.chipselect = davinci_spi_chipselect;
davinci_spi->bitbang.setup_transfer = davinci_spi_setup_transfer;
davinci_spi->version = pdata->version;
use_dma = pdata->use_dma;
davinci_spi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP;
if (davinci_spi->version == SPI_VERSION_2)
davinci_spi->bitbang.flags |= SPI_READY;
if (use_dma) {
r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
if (r)
dma_rx_chan = r->start;
r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
if (r)
dma_tx_chan = r->start;
r = platform_get_resource(pdev, IORESOURCE_DMA, 2);
if (r)
dma_eventq = r->start;
}
if (!use_dma ||
dma_rx_chan == SPI_NO_RESOURCE ||
dma_tx_chan == SPI_NO_RESOURCE ||
dma_eventq == SPI_NO_RESOURCE) {
davinci_spi->bitbang.txrx_bufs = davinci_spi_bufs_pio;
use_dma = 0;
} else {
davinci_spi->bitbang.txrx_bufs = davinci_spi_bufs_dma;
davinci_spi->dma_channels = kzalloc(master->num_chipselect
* sizeof(struct davinci_spi_dma), GFP_KERNEL);
if (davinci_spi->dma_channels == NULL) {
ret = -ENOMEM;
goto free_clk;
}
for (i = 0; i < master->num_chipselect; i++) {
davinci_spi->dma_channels[i].dma_rx_channel = -1;
davinci_spi->dma_channels[i].dma_rx_sync_dev =
dma_rx_chan;
davinci_spi->dma_channels[i].dma_tx_channel = -1;
davinci_spi->dma_channels[i].dma_tx_sync_dev =
dma_tx_chan;
davinci_spi->dma_channels[i].eventq = dma_eventq;
}
dev_info(&pdev->dev, "DaVinci SPI driver in EDMA mode\n"
"Using RX channel = %d , TX channel = %d and "
"event queue = %d", dma_rx_chan, dma_tx_chan,
dma_eventq);
}
davinci_spi->get_rx = davinci_spi_rx_buf_u8;
davinci_spi->get_tx = davinci_spi_tx_buf_u8;
init_completion(&davinci_spi->done);
/* Reset In/OUT SPI module */
iowrite32(0, davinci_spi->base + SPIGCR0);
udelay(100);
iowrite32(1, davinci_spi->base + SPIGCR0);
/* Clock internal */
if (davinci_spi->pdata->clk_internal)
set_io_bits(davinci_spi->base + SPIGCR1,
SPIGCR1_CLKMOD_MASK);
else
clear_io_bits(davinci_spi->base + SPIGCR1,
SPIGCR1_CLKMOD_MASK);
/* master mode default */
set_io_bits(davinci_spi->base + SPIGCR1, SPIGCR1_MASTER_MASK);
if (davinci_spi->pdata->intr_level)
iowrite32(SPI_INTLVL_1, davinci_spi->base + SPILVL);
else
iowrite32(SPI_INTLVL_0, davinci_spi->base + SPILVL);
ret = spi_bitbang_start(&davinci_spi->bitbang);
if (ret)
goto free_clk;
dev_info(&pdev->dev, "Controller at 0x%p \n", davinci_spi->base);
if (!pdata->poll_mode)
dev_info(&pdev->dev, "Operating in interrupt mode"
" using IRQ %d\n", davinci_spi->irq);
return ret;
free_clk:
clk_disable(davinci_spi->clk);
clk_put(davinci_spi->clk);
put_master:
spi_master_put(master);
free_tmp_buf:
kfree(davinci_spi->tmp_buf);
irq_free:
free_irq(davinci_spi->irq, davinci_spi);
unmap_io:
iounmap(davinci_spi->base);
release_region:
release_mem_region(davinci_spi->pbase, davinci_spi->region_size);
free_master:
kfree(master);
err:
return ret;
}
/**
* davinci_spi_remove - remove function for SPI Master Controller
* @pdev: platform_device structure which contains plateform specific data
*
* This function will do the reverse action of davinci_spi_probe function
* It will free the IRQ and SPI controller's memory region.
* It will also call spi_bitbang_stop to destroy the work queue which was
* created by spi_bitbang_start.
*/
static int __exit davinci_spi_remove(struct platform_device *pdev)
{
struct davinci_spi *davinci_spi;
struct spi_master *master;
master = dev_get_drvdata(&pdev->dev);
davinci_spi = spi_master_get_devdata(master);
spi_bitbang_stop(&davinci_spi->bitbang);
clk_disable(davinci_spi->clk);
clk_put(davinci_spi->clk);
spi_master_put(master);
kfree(davinci_spi->tmp_buf);
free_irq(davinci_spi->irq, davinci_spi);
iounmap(davinci_spi->base);
release_mem_region(davinci_spi->pbase, davinci_spi->region_size);
return 0;
}
static struct platform_driver davinci_spi_driver = {
.driver.name = "spi_davinci",
.remove = __exit_p(davinci_spi_remove),
};
static int __init davinci_spi_init(void)
{
return platform_driver_probe(&davinci_spi_driver, davinci_spi_probe);
}
module_init(davinci_spi_init);
static void __exit davinci_spi_exit(void)
{
platform_driver_unregister(&davinci_spi_driver);
}
module_exit(davinci_spi_exit);
MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver");
MODULE_LICENSE("GPL");
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