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spi: microblaze: Adds driver for Xilinx SPI controller

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This is an improved version of the driver patch original
submitted by Graeme Smecher <graeme.smecher@mail.mcgill.ca>

The changes are:
    - remove hard coded Xilinx BSP defines (XPAR_SPI_*) and
      use CONFIG_SYS_SPI_BASE from config.h instead
    - add extensive register struct definitions
    - remove offset calculation for register access and
      use the new register struct instead
    - move default SPI controller configuration from
      spi_setup_slave() to spi_claim_bus()
    - add spi_set_speed()
    - insert SPI controller deactivation in spi_release_bus()
    - protect while loops in spi_xfer() with counter / timeouts
    - support SPI mode flags: LSB_FIRST, CPHA, CPOL, LOOP

Come from:
    http://patchwork.ozlabs.org/patch/71797/

Signed-off-by: Stephan Linz <linz@li-pro.net>
Tested-by: Michal Simek <monstr@monstr.eu>
master
Stephan Linz 13 years ago committed by Michal Simek
parent 575a3d21f6
commit 09aac75e4d
3 changed files with 350 additions and 0 deletions
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  1. 1
      drivers/spi/Makefile
  2. 214
      drivers/spi/xilinx_spi.c
  3. 135
      drivers/spi/xilinx_spi.h

1
drivers/spi/Makefile
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@ -44,6 +44,7 @@ COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
COBJS-$(CONFIG_SH_SPI) += sh_spi.o
COBJS-$(CONFIG_FSL_ESPI) += fsl_espi.o
COBJS-$(CONFIG_TEGRA2_SPI) += tegra2_spi.o
COBJS-$(CONFIG_XILINX_SPI) += xilinx_spi.o
COBJS := $(COBJS-y)
SRCS := $(COBJS:.o=.c)

214
drivers/spi/xilinx_spi.c
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@ -0,0 +1,214 @@
/*
* Xilinx SPI driver
*
* supports 8 bit SPI transfers only, with or w/o FIFO
*
* based on bfin_spi.c, by way of altera_spi.c
* Copyright (c) 2005-2008 Analog Devices Inc.
* Copyright (c) 2010 Thomas Chou <thomas@wytron.com.tw>
* Copyright (c) 2010 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
* Copyright (c) 2012 Stephan Linz <linz@li-pro.net>
*
* Licensed under the GPL-2 or later.
*
* [0]: http://www.xilinx.com/support/documentation
*
* [S]: [0]/ip_documentation/xps_spi.pdf
* [0]/ip_documentation/axi_spi_ds742.pdf
*/
#include <config.h>
#include <common.h>
#include <malloc.h>
#include <spi.h>
#include "xilinx_spi.h"
#ifndef CONFIG_SYS_XILINX_SPI_LIST
#define CONFIG_SYS_XILINX_SPI_LIST { CONFIG_SYS_SPI_BASE }
#endif
#ifndef CONFIG_XILINX_SPI_IDLE_VAL
#define CONFIG_XILINX_SPI_IDLE_VAL 0xff
#endif
#define XILSPI_SPICR_DFLT_ON (SPICR_MANUAL_SS | \
SPICR_MASTER_MODE | \
SPICR_SPE)
#define XILSPI_SPICR_DFLT_OFF (SPICR_MASTER_INHIBIT | \
SPICR_MANUAL_SS)
#define XILSPI_MAX_XFER_BITS 8
static unsigned long xilinx_spi_base_list[] = CONFIG_SYS_XILINX_SPI_LIST;
__attribute__((weak))
int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
return bus < ARRAY_SIZE(xilinx_spi_base_list) && cs < 32;
}
__attribute__((weak))
void spi_cs_activate(struct spi_slave *slave)
{
struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
writel(SPISSR_ACT(slave->cs), &xilspi->regs->spissr);
}
__attribute__((weak))
void spi_cs_deactivate(struct spi_slave *slave)
{
struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
writel(SPISSR_OFF, &xilspi->regs->spissr);
}
void spi_init(void)
{
/* do nothing */
}
void spi_set_speed(struct spi_slave *slave, uint hz)
{
/* xilinx spi core does not support programmable speed */
}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct xilinx_spi_slave *xilspi;
struct xilinx_spi_reg *regs;
if (!spi_cs_is_valid(bus, cs)) {
printf("XILSPI error: %s: unsupported bus %d / cs %d\n",
__func__, bus, cs);
return NULL;
}
xilspi = malloc(sizeof(*xilspi));
if (!xilspi) {
printf("XILSPI error: %s: malloc of SPI structure failed\n",
__func__);
return NULL;
}
xilspi->slave.bus = bus;
xilspi->slave.cs = cs;
xilspi->regs = (struct xilinx_spi_reg *)xilinx_spi_base_list[bus];
xilspi->freq = max_hz;
xilspi->mode = mode;
debug("%s: bus:%i cs:%i base:%p mode:%x max_hz:%d\n", __func__,
bus, cs, xilspi->regs, xilspi->mode, xilspi->freq);
return &xilspi->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
free(xilspi);
}
int spi_claim_bus(struct spi_slave *slave)
{
struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
u32 spicr;
debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
writel(SPISSR_OFF, &xilspi->regs->spissr);
spicr = XILSPI_SPICR_DFLT_ON;
if (xilspi->mode & SPI_LSB_FIRST)
spicr |= SPICR_LSB_FIRST;
if (xilspi->mode & SPI_CPHA)
spicr |= SPICR_CPHA;
if (xilspi->mode & SPI_CPOL)
spicr |= SPICR_CPOL;
if (xilspi->mode & SPI_LOOP)
spicr |= SPICR_LOOP;
writel(spicr, &xilspi->regs->spicr);
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
writel(SPISSR_OFF, &xilspi->regs->spissr);
writel(XILSPI_SPICR_DFLT_OFF, &xilspi->regs->spicr);
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
struct xilinx_spi_slave *xilspi = to_xilinx_spi_slave(slave);
/* assume spi core configured to do 8 bit transfers */
unsigned int bytes = bitlen / XILSPI_MAX_XFER_BITS;
const unsigned char *txp = dout;
unsigned char *rxp = din;
unsigned rxecount = 17; /* max. 16 elements in FIFO, leftover 1 */
debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
slave->bus, slave->cs, bitlen, bytes, flags);
if (bitlen == 0)
goto done;
if (bitlen % XILSPI_MAX_XFER_BITS) {
printf("XILSPI warning: %s: Not a multiple of %d bits\n",
__func__, XILSPI_MAX_XFER_BITS);
flags |= SPI_XFER_END;
goto done;
}
/* empty read buffer */
while (rxecount && !(readl(&xilspi->regs->spisr) & SPISR_RX_EMPTY)) {
readl(&xilspi->regs->spidrr);
rxecount--;
}
if (!rxecount) {
printf("XILSPI error: %s: Rx buffer not empty\n", __func__);
return -1;
}
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave);
while (bytes--) {
unsigned timeout = /* at least 1usec or greater, leftover 1 */
xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
(XILSPI_MAX_XFER_BITS * 1000000 / xilspi->freq) + 1;
/* get Tx element from data out buffer and count up */
unsigned char d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL;
debug("%s: tx:%x ", __func__, d);
/* write out and wait for processing (receive data) */
writel(d & SPIDTR_8BIT_MASK, &xilspi->regs->spidtr);
while (timeout && readl(&xilspi->regs->spisr)
& SPISR_RX_EMPTY) {
timeout--;
udelay(1);
}
if (!timeout) {
printf("XILSPI error: %s: Xfer timeout\n", __func__);
return -1;
}
/* read Rx element and push into data in buffer */
d = readl(&xilspi->regs->spidrr) & SPIDRR_8BIT_MASK;
if (rxp)
*rxp++ = d;
debug("rx:%x\n", d);
}
done:
if (flags & SPI_XFER_END)
spi_cs_deactivate(slave);
return 0;
}

135
drivers/spi/xilinx_spi.h
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@ -0,0 +1,135 @@
/*
* Xilinx SPI driver
*
* XPS/AXI bus interface
*
* based on bfin_spi.c, by way of altera_spi.c
* Copyright (c) 2005-2008 Analog Devices Inc.
* Copyright (c) 2010 Thomas Chou <thomas@wytron.com.tw>
* Copyright (c) 2010 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
* Copyright (c) 2012 Stephan Linz <linz@li-pro.net>
*
* Licensed under the GPL-2 or later.
*
* [0]: http://www.xilinx.com/support/documentation
*
* [S]: [0]/ip_documentation/xps_spi.pdf
* [0]/ip_documentation/axi_spi_ds742.pdf
*/
#ifndef _XILINX_SPI_
#define _XILINX_SPI_
#include <asm/types.h>
#include <asm/io.h>
/*
* Xilinx SPI Register Definition
*
* [1]: [0]/ip_documentation/xps_spi.pdf
* page 8, Register Descriptions
* [2]: [0]/ip_documentation/axi_spi_ds742.pdf
* page 7, Register Overview Table
*/
struct xilinx_spi_reg {
u32 __space0__[7];
u32 dgier; /* Device Global Interrupt Enable Register (DGIER) */
u32 ipisr; /* IP Interrupt Status Register (IPISR) */
u32 __space1__;
u32 ipier; /* IP Interrupt Enable Register (IPIER) */
u32 __space2__[5];
u32 srr; /* Softare Reset Register (SRR) */
u32 __space3__[7];
u32 spicr; /* SPI Control Register (SPICR) */
u32 spisr; /* SPI Status Register (SPISR) */
u32 spidtr; /* SPI Data Transmit Register (SPIDTR) */
u32 spidrr; /* SPI Data Receive Register (SPIDRR) */
u32 spissr; /* SPI Slave Select Register (SPISSR) */
u32 spitfor; /* SPI Transmit FIFO Occupancy Register (SPITFOR) */
u32 spirfor; /* SPI Receive FIFO Occupancy Register (SPIRFOR) */
};
/* Device Global Interrupt Enable Register (dgier), [1] p15, [2] p15 */
#define DGIER_GIE (1 << 31)
/* IP Interrupt Status Register (ipisr), [1] p15, [2] p15 */
#define IPISR_DRR_NOT_EMPTY (1 << 8)
#define IPISR_SLAVE_SELECT (1 << 7)
#define IPISR_TXF_HALF_EMPTY (1 << 6)
#define IPISR_DRR_OVERRUN (1 << 5)
#define IPISR_DRR_FULL (1 << 4)
#define IPISR_DTR_UNDERRUN (1 << 3)
#define IPISR_DTR_EMPTY (1 << 2)
#define IPISR_SLAVE_MODF (1 << 1)
#define IPISR_MODF (1 << 0)
/* IP Interrupt Enable Register (ipier), [1] p17, [2] p18 */
#define IPIER_DRR_NOT_EMPTY (1 << 8)
#define IPIER_SLAVE_SELECT (1 << 7)
#define IPIER_TXF_HALF_EMPTY (1 << 6)
#define IPIER_DRR_OVERRUN (1 << 5)
#define IPIER_DRR_FULL (1 << 4)
#define IPIER_DTR_UNDERRUN (1 << 3)
#define IPIER_DTR_EMPTY (1 << 2)
#define IPIER_SLAVE_MODF (1 << 1)
#define IPIER_MODF (1 << 0)
/* Softare Reset Register (srr), [1] p9, [2] p8 */
#define SRR_RESET_CODE 0x0000000A
/* SPI Control Register (spicr), [1] p9, [2] p8 */
#define SPICR_LSB_FIRST (1 << 9)
#define SPICR_MASTER_INHIBIT (1 << 8)
#define SPICR_MANUAL_SS (1 << 7)
#define SPICR_RXFIFO_RESEST (1 << 6)
#define SPICR_TXFIFO_RESEST (1 << 5)
#define SPICR_CPHA (1 << 4)
#define SPICR_CPOL (1 << 3)
#define SPICR_MASTER_MODE (1 << 2)
#define SPICR_SPE (1 << 1)
#define SPICR_LOOP (1 << 0)
/* SPI Status Register (spisr), [1] p11, [2] p10 */
#define SPISR_SLAVE_MODE_SELECT (1 << 5)
#define SPISR_MODF (1 << 4)
#define SPISR_TX_FULL (1 << 3)
#define SPISR_TX_EMPTY (1 << 2)
#define SPISR_RX_FULL (1 << 1)
#define SPISR_RX_EMPTY (1 << 0)
/* SPI Data Transmit Register (spidtr), [1] p12, [2] p12 */
#define SPIDTR_8BIT_MASK (0xff << 0)
#define SPIDTR_16BIT_MASK (0xffff << 0)
#define SPIDTR_32BIT_MASK (0xffffffff << 0)
/* SPI Data Receive Register (spidrr), [1] p12, [2] p12 */
#define SPIDRR_8BIT_MASK (0xff << 0)
#define SPIDRR_16BIT_MASK (0xffff << 0)
#define SPIDRR_32BIT_MASK (0xffffffff << 0)
/* SPI Slave Select Register (spissr), [1] p13, [2] p13 */
#define SPISSR_MASK(cs) (1 << (cs))
#define SPISSR_ACT(cs) ~SPISSR_MASK(cs)
#define SPISSR_OFF ~0UL
/* SPI Transmit FIFO Occupancy Register (spitfor), [1] p13, [2] p14 */
#define SPITFOR_OCYVAL_POS 0
#define SPITFOR_OCYVAL_MASK (0xf << SPITFOR_OCYVAL_POS)
/* SPI Receive FIFO Occupancy Register (spirfor), [1] p14, [2] p14 */
#define SPIRFOR_OCYVAL_POS 0
#define SPIRFOR_OCYVAL_MASK (0xf << SPIRFOR_OCYVAL_POS)
struct xilinx_spi_slave {
struct spi_slave slave;
struct xilinx_spi_reg *regs;
unsigned int freq;
unsigned int mode;
};
static inline struct xilinx_spi_slave *to_xilinx_spi_slave(
struct spi_slave *slave)
{
return container_of(slave, struct xilinx_spi_slave, slave);
}
#endif /* _XILINX_SPI_ */
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