u-boot/drivers/spi/davinci_spi.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
*
* Driver for SPI controller on DaVinci. Based on atmel_spi.c
* by Atmel Corporation
*
* Copyright (C) 2007 Atmel Corporation
*/
#include <common.h>
#include <log.h>
#include <spi.h>
#include <malloc.h>
#include <asm/io.h>
#include <asm/arch/hardware.h>
#include <dm.h>
#include <dm/platform_data/spi_davinci.h>
#include <linux/bitops.h>
#include <linux/delay.h>
/* SPIGCR0 */
#define SPIGCR0_SPIENA_MASK 0x1
#define SPIGCR0_SPIRST_MASK 0x0
/* SPIGCR0 */
#define SPIGCR1_CLKMOD_MASK BIT(1)
#define SPIGCR1_MASTER_MASK BIT(0)
#define SPIGCR1_SPIENA_MASK BIT(24)
/* SPIPC0 */
#define SPIPC0_DIFUN_MASK BIT(11) /* SIMO */
#define SPIPC0_DOFUN_MASK BIT(10) /* SOMI */
#define SPIPC0_CLKFUN_MASK BIT(9) /* CLK */
#define SPIPC0_EN0FUN_MASK BIT(0)
/* SPIFMT0 */
#define SPIFMT_SHIFTDIR_SHIFT 20
#define SPIFMT_POLARITY_SHIFT 17
#define SPIFMT_PHASE_SHIFT 16
#define SPIFMT_PRESCALE_SHIFT 8
/* SPIDAT1 */
#define SPIDAT1_CSHOLD_SHIFT 28
#define SPIDAT1_CSNR_SHIFT 16
/* SPIDELAY */
#define SPI_C2TDELAY_SHIFT 24
#define SPI_T2CDELAY_SHIFT 16
/* SPIBUF */
#define SPIBUF_RXEMPTY_MASK BIT(31)
#define SPIBUF_TXFULL_MASK BIT(29)
/* SPIDEF */
#define SPIDEF_CSDEF0_MASK BIT(0)
DECLARE_GLOBAL_DATA_PTR;
/* davinci spi register set */
struct davinci_spi_regs {
dv_reg gcr0; /* 0x00 */
dv_reg gcr1; /* 0x04 */
dv_reg int0; /* 0x08 */
dv_reg lvl; /* 0x0c */
dv_reg flg; /* 0x10 */
dv_reg pc0; /* 0x14 */
dv_reg pc1; /* 0x18 */
dv_reg pc2; /* 0x1c */
dv_reg pc3; /* 0x20 */
dv_reg pc4; /* 0x24 */
dv_reg pc5; /* 0x28 */
dv_reg rsvd[3];
dv_reg dat0; /* 0x38 */
dv_reg dat1; /* 0x3c */
dv_reg buf; /* 0x40 */
dv_reg emu; /* 0x44 */
dv_reg delay; /* 0x48 */
dv_reg def; /* 0x4c */
dv_reg fmt0; /* 0x50 */
dv_reg fmt1; /* 0x54 */
dv_reg fmt2; /* 0x58 */
dv_reg fmt3; /* 0x5c */
dv_reg intvec0; /* 0x60 */
dv_reg intvec1; /* 0x64 */
};
/* davinci spi slave */
struct davinci_spi_slave {
struct davinci_spi_regs *regs;
unsigned int freq; /* current SPI bus frequency */
unsigned int mode; /* current SPI mode used */
u8 num_cs; /* total no. of CS available */
u8 cur_cs; /* CS of current slave */
bool half_duplex; /* true, if master is half-duplex only */
};
/*
* This functions needs to act like a macro to avoid pipeline reloads in the
* loops below. Use always_inline. This gains us about 160KiB/s and the bloat
* appears to be zero bytes (da830).
*/
__attribute__((always_inline))
static inline u32 davinci_spi_xfer_data(struct davinci_spi_slave *ds, u32 data)
{
u32 buf_reg_val;
/* send out data */
writel(data, &ds->regs->dat1);
/* wait for the data to clock in/out */
while ((buf_reg_val = readl(&ds->regs->buf)) & SPIBUF_RXEMPTY_MASK)
;
return buf_reg_val;
}
static int davinci_spi_read(struct davinci_spi_slave *ds, unsigned int len,
u8 *rxp, unsigned long flags)
{
unsigned int data1_reg_val;
/* enable CS hold, CS[n] and clear the data bits */
data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
(ds->cur_cs << SPIDAT1_CSNR_SHIFT));
/* wait till TXFULL is deasserted */
while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
;
/* preload the TX buffer to avoid clock starvation */
writel(data1_reg_val, &ds->regs->dat1);
/* keep reading 1 byte until only 1 byte left */
while ((len--) > 1)
*rxp++ = davinci_spi_xfer_data(ds, data1_reg_val);
/* clear CS hold when we reach the end */
if (flags & SPI_XFER_END)
data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
/* read the last byte */
*rxp = davinci_spi_xfer_data(ds, data1_reg_val);
return 0;
}
static int davinci_spi_write(struct davinci_spi_slave *ds, unsigned int len,
const u8 *txp, unsigned long flags)
{
unsigned int data1_reg_val;
/* enable CS hold and clear the data bits */
data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
(ds->cur_cs << SPIDAT1_CSNR_SHIFT));
/* wait till TXFULL is deasserted */
while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
;
/* preload the TX buffer to avoid clock starvation */
if (len > 2) {
writel(data1_reg_val | *txp++, &ds->regs->dat1);
len--;
}
/* keep writing 1 byte until only 1 byte left */
while ((len--) > 1)
davinci_spi_xfer_data(ds, data1_reg_val | *txp++);
/* clear CS hold when we reach the end */
if (flags & SPI_XFER_END)
data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
/* write the last byte */
davinci_spi_xfer_data(ds, data1_reg_val | *txp);
return 0;
}
static int davinci_spi_read_write(struct davinci_spi_slave *ds, unsigned
int len, u8 *rxp, const u8 *txp,
unsigned long flags)
{
unsigned int data1_reg_val;
/* enable CS hold and clear the data bits */
data1_reg_val = ((1 << SPIDAT1_CSHOLD_SHIFT) |
(ds->cur_cs << SPIDAT1_CSNR_SHIFT));
/* wait till TXFULL is deasserted */
while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
;
/* keep reading and writing 1 byte until only 1 byte left */
while ((len--) > 1)
*rxp++ = davinci_spi_xfer_data(ds, data1_reg_val | *txp++);
/* clear CS hold when we reach the end */
if (flags & SPI_XFER_END)
data1_reg_val &= ~(1 << SPIDAT1_CSHOLD_SHIFT);
/* read and write the last byte */
*rxp = davinci_spi_xfer_data(ds, data1_reg_val | *txp);
return 0;
}
static int __davinci_spi_claim_bus(struct davinci_spi_slave *ds, int cs)
{
unsigned int mode = 0, scalar;
/* Enable the SPI hardware */
writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
udelay(1000);
writel(SPIGCR0_SPIENA_MASK, &ds->regs->gcr0);
/* Set master mode, powered up and not activated */
writel(SPIGCR1_MASTER_MASK | SPIGCR1_CLKMOD_MASK, &ds->regs->gcr1);
/* CS, CLK, SIMO and SOMI are functional pins */
writel(((1 << cs) | SPIPC0_CLKFUN_MASK |
SPIPC0_DOFUN_MASK | SPIPC0_DIFUN_MASK), &ds->regs->pc0);
/* setup format */
scalar = ((CONFIG_SYS_SPI_CLK / ds->freq) - 1) & 0xFF;
/*
* Use following format:
* character length = 8,
* MSB shifted out first
*/
if (ds->mode & SPI_CPOL)
mode |= SPI_CPOL;
if (!(ds->mode & SPI_CPHA))
mode |= SPI_CPHA;
writel(8 | (scalar << SPIFMT_PRESCALE_SHIFT) |
(mode << SPIFMT_PHASE_SHIFT), &ds->regs->fmt0);
/*
* Including a minor delay. No science here. Should be good even with
* no delay
*/
writel((50 << SPI_C2TDELAY_SHIFT) |
(50 << SPI_T2CDELAY_SHIFT), &ds->regs->delay);
/* default chip select register */
writel(SPIDEF_CSDEF0_MASK, &ds->regs->def);
/* no interrupts */
writel(0, &ds->regs->int0);
writel(0, &ds->regs->lvl);
/* enable SPI */
writel((readl(&ds->regs->gcr1) | SPIGCR1_SPIENA_MASK), &ds->regs->gcr1);
return 0;
}
static int __davinci_spi_release_bus(struct davinci_spi_slave *ds)
{
/* Disable the SPI hardware */
writel(SPIGCR0_SPIRST_MASK, &ds->regs->gcr0);
return 0;
}
static int __davinci_spi_xfer(struct davinci_spi_slave *ds,
unsigned int bitlen, const void *dout, void *din,
unsigned long flags)
{
unsigned int len;
if (bitlen == 0)
/* Finish any previously submitted transfers */
goto out;
/*
* It's not clear how non-8-bit-aligned transfers are supposed to be
* represented as a stream of bytes...this is a limitation of
* the current SPI interface - here we terminate on receiving such a
* transfer request.
*/
if (bitlen % 8) {
/* Errors always terminate an ongoing transfer */
flags |= SPI_XFER_END;
goto out;
}
len = bitlen / 8;
if (!dout)
return davinci_spi_read(ds, len, din, flags);
if (!din)
return davinci_spi_write(ds, len, dout, flags);
if (!ds->half_duplex)
return davinci_spi_read_write(ds, len, din, dout, flags);
printf("SPI full duplex not supported\n");
flags |= SPI_XFER_END;
out:
if (flags & SPI_XFER_END) {
u8 dummy = 0;
davinci_spi_write(ds, 1, &dummy, flags);
}
return 0;
}
static int davinci_spi_set_speed(struct udevice *bus, uint max_hz)
{
struct davinci_spi_slave *ds = dev_get_priv(bus);
debug("%s speed %u\n", __func__, max_hz);
if (max_hz > CONFIG_SYS_SPI_CLK / 2)
return -EINVAL;
ds->freq = max_hz;
return 0;
}
static int davinci_spi_set_mode(struct udevice *bus, uint mode)
{
struct davinci_spi_slave *ds = dev_get_priv(bus);
debug("%s mode %u\n", __func__, mode);
ds->mode = mode;
return 0;
}
static int davinci_spi_claim_bus(struct udevice *dev)
{
struct dm_spi_slave_plat *slave_plat =
dev_get_parent_plat(dev);
struct udevice *bus = dev->parent;
struct davinci_spi_slave *ds = dev_get_priv(bus);
if (slave_plat->cs >= ds->num_cs) {
printf("Invalid SPI chipselect\n");
return -EINVAL;
}
ds->half_duplex = slave_plat->mode & SPI_PREAMBLE;
return __davinci_spi_claim_bus(ds, slave_plat->cs);
}
static int davinci_spi_release_bus(struct udevice *dev)
{
struct davinci_spi_slave *ds = dev_get_priv(dev->parent);
return __davinci_spi_release_bus(ds);
}
static int davinci_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din,
unsigned long flags)
{
struct dm_spi_slave_plat *slave =
dev_get_parent_plat(dev);
struct udevice *bus = dev->parent;
struct davinci_spi_slave *ds = dev_get_priv(bus);
if (slave->cs >= ds->num_cs) {
printf("Invalid SPI chipselect\n");
return -EINVAL;
}
ds->cur_cs = slave->cs;
return __davinci_spi_xfer(ds, bitlen, dout, din, flags);
}
static const struct dm_spi_ops davinci_spi_ops = {
.claim_bus = davinci_spi_claim_bus,
.release_bus = davinci_spi_release_bus,
.xfer = davinci_spi_xfer,
.set_speed = davinci_spi_set_speed,
.set_mode = davinci_spi_set_mode,
};
static int davinci_spi_probe(struct udevice *bus)
{
struct davinci_spi_slave *ds = dev_get_priv(bus);
struct davinci_spi_plat *plat = dev_get_plat(bus);
ds->regs = plat->regs;
ds->num_cs = plat->num_cs;
return 0;
}
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
static int davinci_ofdata_to_platadata(struct udevice *bus)
{
struct davinci_spi_plat *plat = dev_get_plat(bus);
fdt_addr_t addr;
addr = dev_read_addr(bus);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
plat->regs = (struct davinci_spi_regs *)addr;
plat->num_cs = fdtdec_get_int(gd->fdt_blob, dev_of_offset(bus), "num-cs", 4);
return 0;
}
static const struct udevice_id davinci_spi_ids[] = {
{ .compatible = "ti,keystone-spi" },
{ .compatible = "ti,dm6441-spi" },
{ .compatible = "ti,da830-spi" },
{ }
};
#endif
U_BOOT_DRIVER(davinci_spi) = {
.name = "davinci_spi",
.id = UCLASS_SPI,
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
.of_match = davinci_spi_ids,
.of_to_plat = davinci_ofdata_to_platadata,
.plat_auto = sizeof(struct davinci_spi_plat),
#endif
.probe = davinci_spi_probe,
.ops = &davinci_spi_ops,
.priv_auto = sizeof(struct davinci_spi_slave),
};