/*
* File : spi-davinci.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2006, RT-Thread Development Team
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Change Logs:
* Date Author Notes
* 2011-01-13 weety first version
*/
#include <rthw.h>
#include <rtthread.h>
#include <rtdevice.h>
#include <dm36x.h>
#include <edma.h>
#include "spi-davinci.h"
#define unlikely(x) x
#define barrier() __asm__ __volatile__("": : :"memory")
#define cpu_relax() barrier()
#define SPI_DEBUG 0
#if SPI_DEBUG
#define spi_dbg(dev, fmt, ...) \
do { \
rt_kprintf("%s:", dev->parent.name); \
rt_kprintf(fmt, ##__VA_ARGS__); \
} while(0)
#else
#define spi_dbg(dev, fmt, ...)
#endif
#define SZ_64K 0x10000
#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
#define SPI_NO_RESOURCE ((resource_size_t)-1)
#define SPI_MAX_CHIPSELECT 2
#define CS_DEFAULT 0xFF
#define __iomem
#define BIT(nr) (1UL << (nr))
#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_PRESCALE_SHIFT 8
/* 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 SPIINT_MASKALL 0x0101035F
#define SPIINT_MASKINT 0x0000015F
#define SPI_INTLVL_1 0x000001FF
#define SPI_INTLVL_0 0x00000000
/* SPIDAT1 (upper 16 bit defines) */
#define SPIDAT1_CSHOLD_MASK BIT(12)
/* SPIGCR1 */
#define SPIGCR1_CLKMOD_MASK BIT(1)
#define SPIGCR1_MASTER_MASK BIT(0)
#define SPIGCR1_POWERDOWN_MASK BIT(8)
#define SPIGCR1_LOOPBACK_MASK BIT(16)
#define SPIGCR1_SPIENA_MASK BIT(24)
/* SPIBUF */
#define SPIBUF_TXFULL_MASK BIT(29)
#define SPIBUF_RXEMPTY_MASK BIT(31)
/* SPIDELAY */
#define SPIDELAY_C2TDELAY_SHIFT 24
#define SPIDELAY_C2TDELAY_MASK (0xFF << SPIDELAY_C2TDELAY_SHIFT)
#define SPIDELAY_T2CDELAY_SHIFT 16
#define SPIDELAY_T2CDELAY_MASK (0xFF << SPIDELAY_T2CDELAY_SHIFT)
#define SPIDELAY_T2EDELAY_SHIFT 8
#define SPIDELAY_T2EDELAY_MASK (0xFF << SPIDELAY_T2EDELAY_SHIFT)
#define SPIDELAY_C2EDELAY_SHIFT 0
#define SPIDELAY_C2EDELAY_MASK 0xFF
/* 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_BUF_INIT_ACTIVE_MASK BIT(24)
#define SPIFLG_ERROR_MASK (SPIFLG_DLEN_ERR_MASK \
| SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \
| SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \
| SPIFLG_OVRRUN_MASK)
#define SPIINT_DMA_REQ_EN BIT(16)
/* SPI Controller registers */
#define SPIGCR0 0x00
#define SPIGCR1 0x04
#define SPIINT 0x08
#define SPILVL 0x0c
#define SPIFLG 0x10
#define SPIPC0 0x14
#define SPIDAT1 0x3c
#define SPIBUF 0x40
#define SPIDELAY 0x48
#define SPIDEF 0x4c
#define SPIFMT0 0x50
/* We have 2 DMA channels per CS, one for RX and one for TX */
struct davinci_spi_dma {
int tx_channel;
int rx_channel;
int dummy_param_slot;
enum dma_event_q eventq;
};
/* SPI Controller driver's private data. */
struct davinci_spi {
struct rt_spi_bus parent;
struct clk *clk;
u8 version;
void __iomem *base;
u32 irq;
struct rt_completion done;
const void *tx;
void *rx;
#define SMP_CACHE_BYTES 32
#define SPI_TMP_BUFSZ (SMP_CACHE_BYTES + 1)
u8 rx_tmp_buf[SPI_TMP_BUFSZ];
int rcount;
int wcount;
struct davinci_spi_dma dma;
void (*get_rx)(u32 rx_data, struct davinci_spi *);
u32 (*get_tx)(struct davinci_spi *);
u8 bytes_per_word[SPI_MAX_CHIPSELECT];
u8 chip_sel[SPI_MAX_CHIPSELECT];
struct davinci_spi_config *controller_data;
int cshold_bug;
};
static struct davinci_spi_config davinci_spi_default_cfg;
extern void mmu_clean_dcache(rt_uint32_t buffer, rt_uint32_t size);
extern void mmu_invalidate_dcache(rt_uint32_t buffer, rt_uint32_t size);
static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *dspi)
{
if (dspi->rx) {
u8 *rx = dspi->rx;
*rx++ = (u8)data;
dspi->rx = rx;
}
}
static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *dspi)
{
if (dspi->rx) {
u16 *rx = dspi->rx;
*rx++ = (u16)data;
dspi->rx = rx;
}
}
static u32 davinci_spi_tx_buf_u8(struct davinci_spi *dspi)
{
u32 data = 0;
if (dspi->tx) {
const u8 *tx = dspi->tx;
data = *tx++;
dspi->tx = tx;
}
return data;
}
static u32 davinci_spi_tx_buf_u16(struct davinci_spi *dspi)
{
u32 data = 0;
if (dspi->tx) {
const u16 *tx = dspi->tx;
data = *tx++;
dspi->tx = tx;
}
return data;
}
static inline void set_io_bits(void __iomem *addr, u32 bits)
{
u32 v = readl(addr);
v |= bits;
writel(v, addr);
}
static inline void clear_io_bits(void __iomem *addr, u32 bits)
{
u32 v = readl(addr);
v &= ~bits;
writel(v, addr);
}
/*
* Interface to control the chip select signal
*/
static void davinci_spi_chipselect(struct rt_spi_device *spi, int value)
{
struct davinci_spi *dspi;
u8 chip_sel = (u8)spi->parent.user_data;
u16 spidat1 = CS_DEFAULT;
bool gpio_chipsel = RT_FALSE;
dspi = spi->bus->parent.user_data;
if (chip_sel < SPI_MAX_CHIPSELECT &&
dspi->chip_sel[chip_sel] != SPI_INTERN_CS)
gpio_chipsel = RT_TRUE;
/*
* Board specific chip select logic decides the polarity and cs
* line for the controller
*/
if (gpio_chipsel) {
if (value == 0)
gpio_set_value(dspi->chip_sel[chip_sel], 0);
else
gpio_set_value(dspi->chip_sel[chip_sel], 1);
} else {
spidat1 = readw(dspi->base + SPIDAT1 + 2);
if (value == 0) {
spidat1 |= SPIDAT1_CSHOLD_MASK;
spidat1 &= ~(0x1 << chip_sel);
} else {
spidat1 &= ~SPIDAT1_CSHOLD_MASK;
spidat1 |= 0x03;
}
rt_kprintf("0x%04x\n", spidat1);
writew(spidat1, dspi->base + SPIDAT1 + 2);
}
}
/**
* davinci_spi_get_prescale - Calculates the correct prescale value
* @maxspeed_hz: the maximum rate the SPI clock can run at
*
* This function calculates the prescale value that generates a clock rate
* less than or equal to the specified maximum.
*
* Returns: calculated prescale - 1 for easy programming into SPI registers
* or negative error number if valid prescalar cannot be updated.
*/
static inline int davinci_spi_get_prescale(struct davinci_spi *dspi,
u32 max_speed_hz)
{
int ret;
ret = DIV_ROUND_UP(clk_get_rate(dspi->clk), max_speed_hz);
if (ret < 3) {
rt_kprintf("spi clock freq too high\n");
ret = 3;
}
if (ret > 256) {
rt_kprintf("spi clock freq too litter\n");
ret = 256;
}
/*if (ret < 3 || ret > 256)
return -RT_ERROR;*/
return ret - 1;
}
/**
* 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 rt_spi_device *spi,
struct rt_spi_configuration *cfg)
{
struct davinci_spi *dspi;
struct davinci_spi_config *spicfg;
u8 bits_per_word = 0;
u32 hz = 0, spifmt = 0, prescale = 0;
u8 chip_select = (u8)spi->parent.user_data;
dspi = spi->bus->parent.user_data;
bits_per_word = cfg->data_width;
hz = cfg->max_hz;
/*
* Assign function pointer to appropriate transfer method
* 8bit, 16bit or 32bit transfer
*/
if (bits_per_word <= 8 && bits_per_word >= 2) {
dspi->get_rx = davinci_spi_rx_buf_u8;
dspi->get_tx = davinci_spi_tx_buf_u8;
dspi->bytes_per_word[chip_select] = 1;
} else if (bits_per_word <= 16 && bits_per_word >= 2) {
dspi->get_rx = davinci_spi_rx_buf_u16;
dspi->get_tx = davinci_spi_tx_buf_u16;
dspi->bytes_per_word[chip_select] = 2;
} else
return -RT_ERROR;
/* Set up SPIFMTn register, unique to this chipselect. */
prescale = davinci_spi_get_prescale(dspi, hz);
if (prescale < 0)
return prescale;
spifmt = (prescale << SPIFMT_PRESCALE_SHIFT) | (bits_per_word & 0x1f);
if (!(cfg->mode & RT_SPI_MSB))
spifmt |= SPIFMT_SHIFTDIR_MASK;
if (cfg->mode & RT_SPI_CPOL)
spifmt |= SPIFMT_POLARITY_MASK;
if (!(cfg->mode & RT_SPI_CPHA))
spifmt |= SPIFMT_PHASE_MASK;
/*
* 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 (dspi->version == SPI_VERSION_2) {
u32 delay = 0;
spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT)
& SPIFMT_WDELAY_MASK);
if (spicfg->odd_parity)
spifmt |= SPIFMT_ODD_PARITY_MASK;
if (spicfg->parity_enable)
spifmt |= SPIFMT_PARITYENA_MASK;
if (spicfg->timer_disable) {
spifmt |= SPIFMT_DISTIMER_MASK;
} else {
delay |= (spicfg->c2tdelay << SPIDELAY_C2TDELAY_SHIFT)
& SPIDELAY_C2TDELAY_MASK;
delay |= (spicfg->t2cdelay << SPIDELAY_T2CDELAY_SHIFT)
& SPIDELAY_T2CDELAY_MASK;
}
if (cfg->mode & RT_SPI_READY) {
spifmt |= SPIFMT_WAITENA_MASK;
delay |= (spicfg->t2edelay << SPIDELAY_T2EDELAY_SHIFT)
& SPIDELAY_T2EDELAY_MASK;
delay |= (spicfg->c2edelay << SPIDELAY_C2EDELAY_SHIFT)
& SPIDELAY_C2EDELAY_MASK;
}
writel(delay, dspi->base + SPIDELAY);
}
writel(spifmt, dspi->base + SPIFMT0);
return 0;
}
#if 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 = 0;
struct davinci_spi *dspi;
struct davinci_spi_platform_data *pdata;
dspi = spi_master_get_devdata(spi->master);
pdata = dspi->pdata;
/* if bits per word length is zero then set it default 8 */
if (!spi->bits_per_word)
spi->bits_per_word = 8;
if (!(spi->mode & SPI_NO_CS)) {
if ((pdata->chip_sel == NULL) ||
(pdata->chip_sel[spi->chip_select] == SPI_INTERN_CS))
set_io_bits(dspi->base + SPIPC0, 1 << spi->chip_select);
}
if (spi->mode & SPI_READY)
set_io_bits(dspi->base + SPIPC0, SPIPC0_SPIENA_MASK);
if (spi->mode & SPI_LOOP)
set_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK);
else
clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK);
return retval;
}
#endif
static int davinci_spi_check_error(struct davinci_spi *dspi, int int_status)
{
struct rt_device *sdev = &dspi->parent.parent;
if (int_status & SPIFLG_TIMEOUT_MASK) {
spi_dbg(sdev, "SPI Time-out Error\n");
return -RT_ETIMEOUT;
}
if (int_status & SPIFLG_DESYNC_MASK) {
spi_dbg(sdev, "SPI Desynchronization Error\n");
return -RT_EIO;
}
if (int_status & SPIFLG_BITERR_MASK) {
spi_dbg(sdev, "SPI Bit error\n");
return -RT_EIO;
}
if (dspi->version == SPI_VERSION_2) {
if (int_status & SPIFLG_DLEN_ERR_MASK) {
spi_dbg(sdev, "SPI Data Length Error\n");
return -RT_EIO;
}
if (int_status & SPIFLG_PARERR_MASK) {
spi_dbg(sdev, "SPI Parity Error\n");
return -RT_EIO;
}
if (int_status & SPIFLG_OVRRUN_MASK) {
spi_dbg(sdev, "SPI Data Overrun error\n");
return -RT_EIO;
}
if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) {
spi_dbg(sdev, "SPI Buffer Init Active\n");
return -RT_EBUSY;
}
}
return 0;
}
/**
* davinci_spi_process_events - check for and handle any SPI controller events
* @dspi: the controller data
*
* This function will check the SPIFLG register and handle any events that are
* detected there
*/
static int davinci_spi_process_events(struct davinci_spi *dspi)
{
u32 buf, status, errors = 0, spidat1;
buf = readl(dspi->base + SPIBUF);
if (dspi->rcount > 0 && !(buf & SPIBUF_RXEMPTY_MASK)) {
dspi->get_rx(buf & 0xFFFF, dspi);
dspi->rcount--;
}
status = readl(dspi->base + SPIFLG);
if (unlikely(status & SPIFLG_ERROR_MASK)) {
errors = status & SPIFLG_ERROR_MASK;
goto out;
}
if (dspi->wcount > 0 && !(buf & SPIBUF_TXFULL_MASK)) {
spidat1 = readl(dspi->base + SPIDAT1);
dspi->wcount--;
spidat1 &= ~0xFFFF;
spidat1 |= 0xFFFF & dspi->get_tx(dspi);
writel(spidat1, dspi->base + SPIDAT1);
}
out:
return errors;
}
static void davinci_spi_dma_callback(unsigned lch, u16 status, void *data)
{
struct davinci_spi *dspi = data;
struct davinci_spi_dma *dma = &dspi->dma;
edma_stop(lch);
if (status == DMA_COMPLETE) {
if (lch == dma->rx_channel)
dspi->rcount = 0;
if (lch == dma->tx_channel)
dspi->wcount = 0;
}
if ((!dspi->wcount && !dspi->rcount) || (status != DMA_COMPLETE))
rt_completion_done(&dspi->done);
}
/**
* 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(struct rt_spi_device *spi, struct rt_spi_message *msg)
{
struct davinci_spi *dspi;
int data_type, ret;
u32 tx_data, spidat1;
u32 errors = 0;
struct davinci_spi_config *spicfg;
unsigned rx_buf_count;
struct rt_device *sdev;
u8 chip_select = (u8)spi->parent.user_data;
dspi = spi->bus->parent.user_data;
spicfg = (struct davinci_spi_config *)dspi->controller_data;
if (!spicfg)
spicfg = &davinci_spi_default_cfg;
sdev = &dspi->parent.parent;
/* convert len to words based on bits_per_word */
data_type = dspi->bytes_per_word[chip_select];
dspi->tx = msg->send_buf;
dspi->rx = msg->recv_buf;
dspi->wcount = msg->length / data_type;
dspi->rcount = dspi->wcount;
spidat1 = readl(dspi->base + SPIDAT1);
clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
set_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
rt_completion_init(&(dspi->done));
if (msg->cs_take)
davinci_spi_chipselect(spi, 0);
if (spicfg->io_type == SPI_IO_TYPE_INTR)
set_io_bits(dspi->base + SPIINT, SPIINT_MASKINT);
if (msg->length > 0) {
if (spicfg->io_type != SPI_IO_TYPE_DMA) {
/* start the transfer */
dspi->wcount--;
tx_data = dspi->get_tx(dspi);
spidat1 &= 0xFFFF0000;
spidat1 |= tx_data & 0xFFFF;
writel(spidat1, dspi->base + SPIDAT1);
} else {
struct davinci_spi_dma *dma;
unsigned long tx_reg, rx_reg;
struct edmacc_param param;
void *rx_buf;
int b, c;
dma = &dspi->dma;
tx_reg = (unsigned long)dspi->base + SPIDAT1;
rx_reg = (unsigned long)dspi->base + SPIBUF;
/*
* Transmit DMA setup
*
* If there is transmit data, map the transmit buffer, set it
* as the source of data and set the source B index to data
* size. If there is no transmit data, set the transmit register
* as the source of data, and set the source B index to zero.
*
* The destination is always the transmit register itself. And
* the destination never increments.
*/
if (msg->send_buf) {
mmu_clean_dcache((rt_uint32_t)msg->send_buf, (rt_uint32_t)msg->length);
}
/*
* If number of words is greater than 65535, then we need
* to configure a 3 dimension transfer. Use the BCNTRLD
* feature to allow for transfers that aren't even multiples
* of 65535 (or any other possible b size) by first transferring
* the remainder amount then grabbing the next N blocks of
* 65535 words.
*/
c = dspi->wcount / (SZ_64K - 1); /* N 65535 Blocks */
b = dspi->wcount - c * (SZ_64K - 1); /* Remainder */
if (b)
c++;
else
b = SZ_64K - 1;
param.opt = TCINTEN | EDMA_TCC(dma->tx_channel);
param.src = msg->send_buf ? msg->send_buf : tx_reg;
param.a_b_cnt = b << 16 | data_type;
param.dst = tx_reg;
param.src_dst_bidx = msg->send_buf ? data_type : 0;
param.link_bcntrld = 0xffffffff;
param.src_dst_cidx = msg->send_buf ? data_type : 0;
param.ccnt = c;
edma_write_slot(dma->tx_channel, ¶m);
edma_link(dma->tx_channel, dma->dummy_param_slot);
/*
* Receive DMA setup
*
* If there is receive buffer, use it to receive data. If there
* is none provided, use a temporary receive buffer. Set the
* destination B index to 0 so effectively only one byte is used
* in the temporary buffer (address does not increment).
*
* The source of receive data is the receive data register. The
* source address never increments.
*/
if (msg->recv_buf) {
rx_buf = msg->recv_buf;
rx_buf_count = msg->length;
} else {
rx_buf = dspi->rx_tmp_buf;
rx_buf_count = sizeof(dspi->rx_tmp_buf);
}
mmu_invalidate_dcache((rt_uint32_t)rx_buf, (rt_uint32_t)rx_buf_count);
param.opt = TCINTEN | EDMA_TCC(dma->rx_channel);
param.src = rx_reg;
param.a_b_cnt = b << 16 | data_type;
param.dst = rx_buf;
param.src_dst_bidx = (msg->recv_buf ? data_type : 0) << 16;
param.link_bcntrld = 0xffffffff;
param.src_dst_cidx = (msg->recv_buf ? data_type : 0) << 16;
param.ccnt = c;
edma_write_slot(dma->rx_channel, ¶m);
if (dspi->cshold_bug)
writew(spidat1 >> 16, dspi->base + SPIDAT1 + 2);
edma_start(dma->rx_channel);
edma_start(dma->tx_channel);
set_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN);
}
/* Wait for the transfer to complete */
if (spicfg->io_type != SPI_IO_TYPE_POLL) {
rt_completion_wait(&(dspi->done), RT_WAITING_FOREVER);
} else {
while (dspi->rcount > 0 || dspi->wcount > 0) {
errors = davinci_spi_process_events(dspi);
if (errors)
break;
cpu_relax();
}
}
}
if (msg->cs_release)
davinci_spi_chipselect(spi, 1);
clear_io_bits(dspi->base + SPIINT, SPIINT_MASKALL);
if (spicfg->io_type == SPI_IO_TYPE_DMA) {
clear_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN);
}
clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
/*
* Check for bit error, desync error,parity error,timeout error and
* receive overflow errors
*/
if (errors) {
ret = davinci_spi_check_error(dspi, errors);
rt_kprintf("%s: error reported but no error found!\n",
spi->bus->parent.parent.name);
return ret;
}
if (dspi->rcount != 0 || dspi->wcount != 0) {
spi_dbg(sdev, "SPI data transfer error\n");
return -RT_EIO;
}
return msg->length;
}
/**
* davinci_spi_irq - Interrupt handler for SPI Master Controller
* @irq: IRQ number for this SPI Master
* @context_data: structure for SPI Master controller davinci_spi
*
* ISR will determine that interrupt arrives either for READ or WRITE command.
* According to command it will do the appropriate action. It will check
* transfer length and if it is not zero then dispatch transfer command again.
* If transfer length is zero then it will indicate the COMPLETION so that
* davinci_spi_bufs function can go ahead.
*/
static void davinci_spi_irq(int irq, void *data)
{
struct davinci_spi *dspi = data;
int status;
status = davinci_spi_process_events(dspi);
if (unlikely(status != 0))
clear_io_bits(dspi->base + SPIINT, SPIINT_MASKINT);
if ((!dspi->rcount && !dspi->wcount) || status)
rt_completion_done(&dspi->done);
}
static int davinci_spi_request_dma(struct davinci_spi *dspi)
{
int r;
struct davinci_spi_dma *dma = &dspi->dma;
r = edma_alloc_channel(dma->rx_channel, davinci_spi_dma_callback, dspi,
dma->eventq);
if (r < 0) {
rt_kprintf("Unable to request DMA channel for SPI RX\n");
r = -RT_EFULL;
goto rx_dma_failed;
}
r = edma_alloc_channel(dma->tx_channel, davinci_spi_dma_callback, dspi,
dma->eventq);
if (r < 0) {
rt_kprintf("Unable to request DMA channel for SPI TX\n");
r = -RT_EFULL;
goto tx_dma_failed;
}
r = edma_alloc_slot(EDMA_CTLR(dma->tx_channel), EDMA_SLOT_ANY);
if (r < 0) {
rt_kprintf("Unable to request SPI TX DMA param slot\n");
r = -RT_EFULL;
goto param_failed;
}
dma->dummy_param_slot = r;
edma_link(dma->dummy_param_slot, dma->dummy_param_slot);
return 0;
param_failed:
edma_free_channel(dma->tx_channel);
tx_dma_failed:
edma_free_channel(dma->rx_channel);
rx_dma_failed:
return r;
}
static rt_err_t configure(struct rt_spi_device *device,
struct rt_spi_configuration *configuration)
{
return davinci_spi_setup_transfer(device, configuration);
}
static rt_uint32_t xfer(struct rt_spi_device *device, struct rt_spi_message *message)
{
return davinci_spi_bufs(device, message);
};
static struct rt_spi_ops davinci_spi_ops =
{
configure,
xfer
};
static void udelay (volatile rt_uint32_t us)
{
volatile rt_int32_t i;
for (; us > 0; us--)
{
i = 5000;
while(i > 0)
{
i--;
}
}
}
void spi_pin_cfg(void)
{
rt_uint32_t val;
val = davinci_readl(PINMUX3);
val |= 0x80000000; /* SPI1 */
davinci_writel(val, PINMUX3);
val = davinci_readl(PINMUX4);
val &= 0xffffffc0; /* SPI1 */
val |= 0x05;//0x00000015; /* SPI1 */
davinci_writel(val, PINMUX4);
}
/**
* davinci_spi_probe - probe function for SPI Master Controller
* @pdev: platform_device structure which contains plateform specific data
*
* According to Linux Device Model this function will be invoked by Linux
* with platform_device struct which contains the device specific info.
* This function will map the SPI controller's memory, register IRQ,
* Reset SPI controller and setting its registers to default value.
* It will invoke spi_bitbang_start to create work queue so that client driver
* can register transfer method to work queue.
*/
static int davinci_spi_probe(struct davinci_spi *dspi, char *spi_bus_name)
{
int i = 0, ret = 0;
u32 spipc0;
spi_pin_cfg();
psc_change_state(DAVINCI_DM365_LPSC_SPI1, PSC_ENABLE);
dspi->base = DM3XX_SPI1_BASE;//spi;
dspi->irq = IRQ_DM3XX_SPINT1_0;
rt_hw_interrupt_install(dspi->irq, davinci_spi_irq, dspi, spi_bus_name);
rt_hw_interrupt_umask(dspi->irq);
dspi->clk = clk_get("SPICLK");
dspi->version = SPI_VERSION_1;
dspi->chip_sel[0] = 29;//SPI_INTERN_CS;
dspi->chip_sel[1] = 0;//GPIO0
dspi->dma.rx_channel = 15;
dspi->dma.tx_channel = 14;
dspi->dma.eventq = EVENTQ_3;
ret = davinci_spi_request_dma(dspi);
if (ret)
goto err;
rt_kprintf("%s: DMA: supported\n", spi_bus_name);
rt_kprintf("%s: DMA: RX channel: %d, TX channel: %d, "
"event queue: %d\n", spi_bus_name, dspi->dma.rx_channel,
dspi->dma.tx_channel, dspi->dma.eventq);
dspi->get_rx = davinci_spi_rx_buf_u8;
dspi->get_tx = davinci_spi_tx_buf_u8;
rt_completion_init(&dspi->done);
/* Reset In/OUT SPI module */
writel(0, dspi->base + SPIGCR0);
udelay(100);
writel(1, dspi->base + SPIGCR0);
/* Set up SPIPC0. CS and ENA init is done in davinci_spi_setup */
spipc0 = SPIPC0_DIFUN_MASK | SPIPC0_DOFUN_MASK | SPIPC0_CLKFUN_MASK;
writel(spipc0, dspi->base + SPIPC0);
/* initialize chip selects */
for (i = 0; i < SPI_MAX_CHIPSELECT; i++) {
if (dspi->chip_sel[i] != SPI_INTERN_CS)
gpio_direction_output(dspi->chip_sel[i], 1);
}
if (0)
writel(SPI_INTLVL_1, dspi->base + SPILVL);
else
writel(SPI_INTLVL_0, dspi->base + SPILVL);
writel(CS_DEFAULT, dspi->base + SPIDEF);
/* master mode default */
set_io_bits(dspi->base + SPIGCR1, SPIGCR1_CLKMOD_MASK);
set_io_bits(dspi->base + SPIGCR1, SPIGCR1_MASTER_MASK);
set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK);
//set_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK);//LOOP BACK mode
rt_kprintf("%s: Controller at 0x%p\n", spi_bus_name, dspi->base);
dspi->parent.parent.user_data = dspi;
return rt_spi_bus_register(&dspi->parent, spi_bus_name, &davinci_spi_ops);
return ret;
free_dma:
edma_free_channel(dspi->dma.tx_channel);
edma_free_channel(dspi->dma.rx_channel);
edma_free_slot(dspi->dma.dummy_param_slot);
err:
return ret;
}
int rt_hw_spi_init(void)
{
/* register spi bus */
{
static struct davinci_spi dspi;
rt_memset(&dspi, 0, sizeof(dspi));
davinci_spi_probe(&dspi, "spi1");
}
/* attach cs */
{
static struct rt_spi_device spi_device;
rt_spi_bus_attach_device(&spi_device, "spi10", "spi1", (void *)0);
}
{
static struct rt_spi_device spi_device;
rt_spi_bus_attach_device(&spi_device, "spi11", "spi1", (void *)1);
}
return 0;
}