u-boot/drivers/spi/xilinx_spi.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* 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) 2015 Jagan Teki <jteki@openedev.com>
* Copyright (c) 2012 Stephan Linz <linz@li-pro.net>
* Copyright (c) 2010 Graeme Smecher <graeme.smecher@mail.mcgill.ca>
* Copyright (c) 2010 Thomas Chou <thomas@wytron.com.tw>
* Copyright (c) 2005-2008 Analog Devices Inc.
*/
#include <config.h>
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <malloc.h>
#include <spi.h>
#include <asm/io.h>
/*
* [0]: http://www.xilinx.com/support/documentation
*
* Xilinx SPI Register Definitions
* [1]: [0]/ip_documentation/xps_spi.pdf
* page 8, Register Descriptions
* [2]: [0]/ip_documentation/axi_spi_ds742.pdf
* page 7, Register Overview Table
*/
/* SPI Control Register (spicr), [1] p9, [2] p8 */
#define SPICR_LSB_FIRST BIT(9)
#define SPICR_MASTER_INHIBIT BIT(8)
#define SPICR_MANUAL_SS BIT(7)
#define SPICR_RXFIFO_RESEST BIT(6)
#define SPICR_TXFIFO_RESEST BIT(5)
#define SPICR_CPHA BIT(4)
#define SPICR_CPOL BIT(3)
#define SPICR_MASTER_MODE BIT(2)
#define SPICR_SPE BIT(1)
#define SPICR_LOOP BIT(0)
/* SPI Status Register (spisr), [1] p11, [2] p10 */
#define SPISR_SLAVE_MODE_SELECT BIT(5)
#define SPISR_MODF BIT(4)
#define SPISR_TX_FULL BIT(3)
#define SPISR_TX_EMPTY BIT(2)
#define SPISR_RX_FULL BIT(1)
#define SPISR_RX_EMPTY BIT(0)
/* SPI Data Transmit Register (spidtr), [1] p12, [2] p12 */
#define SPIDTR_8BIT_MASK GENMASK(7, 0)
#define SPIDTR_16BIT_MASK GENMASK(15, 0)
#define SPIDTR_32BIT_MASK GENMASK(31, 0)
/* SPI Data Receive Register (spidrr), [1] p12, [2] p12 */
#define SPIDRR_8BIT_MASK GENMASK(7, 0)
#define SPIDRR_16BIT_MASK GENMASK(15, 0)
#define SPIDRR_32BIT_MASK GENMASK(31, 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 Software Reset Register (ssr) */
#define SPISSR_RESET_VALUE 0x0a
#define XILSPI_MAX_XFER_BITS 8
#define XILSPI_SPICR_DFLT_ON (SPICR_MANUAL_SS | SPICR_MASTER_MODE | \
SPICR_SPE)
#define XILSPI_SPICR_DFLT_OFF (SPICR_MASTER_INHIBIT | SPICR_MANUAL_SS)
#ifndef CONFIG_XILINX_SPI_IDLE_VAL
#define CONFIG_XILINX_SPI_IDLE_VAL GENMASK(7, 0)
#endif
#ifndef CONFIG_SYS_XILINX_SPI_LIST
#define CONFIG_SYS_XILINX_SPI_LIST { CONFIG_SYS_SPI_BASE }
#endif
/* xilinx spi register set */
struct xilinx_spi_regs {
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) */
};
/* xilinx spi priv */
struct xilinx_spi_priv {
struct xilinx_spi_regs *regs;
unsigned int freq;
unsigned int mode;
};
static unsigned long xilinx_spi_base_list[] = CONFIG_SYS_XILINX_SPI_LIST;
static int xilinx_spi_probe(struct udevice *bus)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
priv->regs = (struct xilinx_spi_regs *)xilinx_spi_base_list[bus->seq];
writel(SPISSR_RESET_VALUE, &regs->srr);
return 0;
}
static void spi_cs_activate(struct udevice *dev, uint cs)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
writel(SPISSR_ACT(cs), &regs->spissr);
}
static void spi_cs_deactivate(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
writel(SPISSR_OFF, &regs->spissr);
}
static int xilinx_spi_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
writel(SPISSR_OFF, &regs->spissr);
writel(XILSPI_SPICR_DFLT_ON, &regs->spicr);
return 0;
}
static int xilinx_spi_release_bus(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
writel(SPISSR_OFF, &regs->spissr);
writel(XILSPI_SPICR_DFLT_OFF, &regs->spicr);
return 0;
}
static int xilinx_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev_get_parent(dev);
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
/* 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 */
unsigned global_timeout;
debug("spi_xfer: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n",
bus->seq, slave_plat->cs, bitlen, bytes, flags);
if (bitlen == 0)
goto done;
if (bitlen % XILSPI_MAX_XFER_BITS) {
printf("XILSPI warning: Not a multiple of %d bits\n",
XILSPI_MAX_XFER_BITS);
flags |= SPI_XFER_END;
goto done;
}
/* empty read buffer */
while (rxecount && !(readl(&regs->spisr) & SPISR_RX_EMPTY)) {
readl(&regs->spidrr);
rxecount--;
}
if (!rxecount) {
printf("XILSPI error: Rx buffer not empty\n");
return -1;
}
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(dev, slave_plat->cs);
/* at least 1usec or greater, leftover 1 */
global_timeout = priv->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
(XILSPI_MAX_XFER_BITS * 1000000 / priv->freq) + 1;
while (bytes--) {
unsigned timeout = global_timeout;
/* get Tx element from data out buffer and count up */
unsigned char d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL;
debug("spi_xfer: tx:%x ", d);
/* write out and wait for processing (receive data) */
writel(d & SPIDTR_8BIT_MASK, &regs->spidtr);
while (timeout && readl(&regs->spisr)
& SPISR_RX_EMPTY) {
timeout--;
udelay(1);
}
if (!timeout) {
printf("XILSPI error: Xfer timeout\n");
return -1;
}
/* read Rx element and push into data in buffer */
d = readl(&regs->spidrr) & SPIDRR_8BIT_MASK;
if (rxp)
*rxp++ = d;
debug("spi_xfer: rx:%x\n", d);
}
done:
if (flags & SPI_XFER_END)
spi_cs_deactivate(dev);
return 0;
}
static int xilinx_spi_set_speed(struct udevice *bus, uint speed)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
priv->freq = speed;
debug("xilinx_spi_set_speed: regs=%p, speed=%d\n", priv->regs,
priv->freq);
return 0;
}
static int xilinx_spi_set_mode(struct udevice *bus, uint mode)
{
struct xilinx_spi_priv *priv = dev_get_priv(bus);
struct xilinx_spi_regs *regs = priv->regs;
uint32_t spicr;
spicr = readl(&regs->spicr);
if (mode & SPI_LSB_FIRST)
spicr |= SPICR_LSB_FIRST;
if (mode & SPI_CPHA)
spicr |= SPICR_CPHA;
if (mode & SPI_CPOL)
spicr |= SPICR_CPOL;
if (mode & SPI_LOOP)
spicr |= SPICR_LOOP;
writel(spicr, &regs->spicr);
priv->mode = mode;
debug("xilinx_spi_set_mode: regs=%p, mode=%d\n", priv->regs,
priv->mode);
return 0;
}
static const struct dm_spi_ops xilinx_spi_ops = {
.claim_bus = xilinx_spi_claim_bus,
.release_bus = xilinx_spi_release_bus,
.xfer = xilinx_spi_xfer,
.set_speed = xilinx_spi_set_speed,
.set_mode = xilinx_spi_set_mode,
};
static const struct udevice_id xilinx_spi_ids[] = {
{ .compatible = "xlnx,xps-spi-2.00.a" },
{ .compatible = "xlnx,xps-spi-2.00.b" },
{ }
};
U_BOOT_DRIVER(xilinx_spi) = {
.name = "xilinx_spi",
.id = UCLASS_SPI,
.of_match = xilinx_spi_ids,
.ops = &xilinx_spi_ops,
.priv_auto_alloc_size = sizeof(struct xilinx_spi_priv),
.probe = xilinx_spi_probe,
};