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u-boot/drivers/spi/xilinx_spi.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style 
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

301 lines
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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,
};
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