u-boot/drivers/spi/atmel_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

515 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2007 Atmel Corporation
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <fdtdec.h>
#include <spi.h>
#include <malloc.h>
#include <wait_bit.h>
#include <asm/io.h>
#include <asm/arch/clk.h>
#include <asm/arch/hardware.h>
#ifdef CONFIG_DM_SPI
#include <asm/arch/at91_spi.h>
#endif
#ifdef CONFIG_DM_GPIO
#include <asm/gpio.h>
#endif
#include "atmel_spi.h"
#ifndef CONFIG_DM_SPI
static int spi_has_wdrbt(struct atmel_spi_slave *slave)
{
unsigned int ver;
ver = spi_readl(slave, VERSION);
return (ATMEL_SPI_VERSION_REV(ver) >= 0x210);
}
void spi_init()
{
}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct atmel_spi_slave *as;
unsigned int scbr;
u32 csrx;
void *regs;
if (!spi_cs_is_valid(bus, cs))
return NULL;
switch (bus) {
case 0:
regs = (void *)ATMEL_BASE_SPI0;
break;
#ifdef ATMEL_BASE_SPI1
case 1:
regs = (void *)ATMEL_BASE_SPI1;
break;
#endif
#ifdef ATMEL_BASE_SPI2
case 2:
regs = (void *)ATMEL_BASE_SPI2;
break;
#endif
#ifdef ATMEL_BASE_SPI3
case 3:
regs = (void *)ATMEL_BASE_SPI3;
break;
#endif
default:
return NULL;
}
scbr = (get_spi_clk_rate(bus) + max_hz - 1) / max_hz;
if (scbr > ATMEL_SPI_CSRx_SCBR_MAX)
/* Too low max SCK rate */
return NULL;
if (scbr < 1)
scbr = 1;
csrx = ATMEL_SPI_CSRx_SCBR(scbr);
csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8);
if (!(mode & SPI_CPHA))
csrx |= ATMEL_SPI_CSRx_NCPHA;
if (mode & SPI_CPOL)
csrx |= ATMEL_SPI_CSRx_CPOL;
as = spi_alloc_slave(struct atmel_spi_slave, bus, cs);
if (!as)
return NULL;
as->regs = regs;
as->mr = ATMEL_SPI_MR_MSTR | ATMEL_SPI_MR_MODFDIS
| ATMEL_SPI_MR_PCS(~(1 << cs) & 0xf);
if (spi_has_wdrbt(as))
as->mr |= ATMEL_SPI_MR_WDRBT;
spi_writel(as, CSR(cs), csrx);
return &as->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);
free(as);
}
int spi_claim_bus(struct spi_slave *slave)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);
/* Enable the SPI hardware */
spi_writel(as, CR, ATMEL_SPI_CR_SPIEN);
/*
* Select the slave. This should set SCK to the correct
* initial state, etc.
*/
spi_writel(as, MR, as->mr);
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);
/* Disable the SPI hardware */
spi_writel(as, CR, ATMEL_SPI_CR_SPIDIS);
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);
unsigned int len_tx;
unsigned int len_rx;
unsigned int len;
u32 status;
const u8 *txp = dout;
u8 *rxp = din;
u8 value;
if (bitlen == 0)
/* Finish any previously submitted transfers */
goto out;
/*
* TODO: The controller can do non-multiple-of-8 bit
* transfers, but this driver currently doesn't support it.
*
* It's also not clear how such transfers are supposed to be
* represented as a stream of bytes...this is a limitation of
* the current SPI interface.
*/
if (bitlen % 8) {
/* Errors always terminate an ongoing transfer */
flags |= SPI_XFER_END;
goto out;
}
len = bitlen / 8;
/*
* The controller can do automatic CS control, but it is
* somewhat quirky, and it doesn't really buy us much anyway
* in the context of U-Boot.
*/
if (flags & SPI_XFER_BEGIN) {
spi_cs_activate(slave);
/*
* sometimes the RDR is not empty when we get here,
* in theory that should not happen, but it DOES happen.
* Read it here to be on the safe side.
* That also clears the OVRES flag. Required if the
* following loop exits due to OVRES!
*/
spi_readl(as, RDR);
}
for (len_tx = 0, len_rx = 0; len_rx < len; ) {
status = spi_readl(as, SR);
if (status & ATMEL_SPI_SR_OVRES)
return -1;
if (len_tx < len && (status & ATMEL_SPI_SR_TDRE)) {
if (txp)
value = *txp++;
else
value = 0;
spi_writel(as, TDR, value);
len_tx++;
}
if (status & ATMEL_SPI_SR_RDRF) {
value = spi_readl(as, RDR);
if (rxp)
*rxp++ = value;
len_rx++;
}
}
out:
if (flags & SPI_XFER_END) {
/*
* Wait until the transfer is completely done before
* we deactivate CS.
*/
do {
status = spi_readl(as, SR);
} while (!(status & ATMEL_SPI_SR_TXEMPTY));
spi_cs_deactivate(slave);
}
return 0;
}
#else
#define MAX_CS_COUNT 4
struct atmel_spi_platdata {
struct at91_spi *regs;
};
struct atmel_spi_priv {
unsigned int freq; /* Default frequency */
unsigned int mode;
ulong bus_clk_rate;
#ifdef CONFIG_DM_GPIO
struct gpio_desc cs_gpios[MAX_CS_COUNT];
#endif
};
static int atmel_spi_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
struct atmel_spi_priv *priv = dev_get_priv(bus);
struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
struct at91_spi *reg_base = bus_plat->regs;
u32 cs = slave_plat->cs;
u32 freq = priv->freq;
u32 scbr, csrx, mode;
scbr = (priv->bus_clk_rate + freq - 1) / freq;
if (scbr > ATMEL_SPI_CSRx_SCBR_MAX)
return -EINVAL;
if (scbr < 1)
scbr = 1;
csrx = ATMEL_SPI_CSRx_SCBR(scbr);
csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8);
if (!(priv->mode & SPI_CPHA))
csrx |= ATMEL_SPI_CSRx_NCPHA;
if (priv->mode & SPI_CPOL)
csrx |= ATMEL_SPI_CSRx_CPOL;
writel(csrx, &reg_base->csr[cs]);
mode = ATMEL_SPI_MR_MSTR |
ATMEL_SPI_MR_MODFDIS |
ATMEL_SPI_MR_WDRBT |
ATMEL_SPI_MR_PCS(~(1 << cs));
writel(mode, &reg_base->mr);
writel(ATMEL_SPI_CR_SPIEN, &reg_base->cr);
return 0;
}
static int atmel_spi_release_bus(struct udevice *dev)
{
struct udevice *bus = dev_get_parent(dev);
struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
writel(ATMEL_SPI_CR_SPIDIS, &bus_plat->regs->cr);
return 0;
}
static void atmel_spi_cs_activate(struct udevice *dev)
{
#ifdef CONFIG_DM_GPIO
struct udevice *bus = dev_get_parent(dev);
struct atmel_spi_priv *priv = dev_get_priv(bus);
struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
u32 cs = slave_plat->cs;
if (!dm_gpio_is_valid(&priv->cs_gpios[cs]))
return;
dm_gpio_set_value(&priv->cs_gpios[cs], 0);
#endif
}
static void atmel_spi_cs_deactivate(struct udevice *dev)
{
#ifdef CONFIG_DM_GPIO
struct udevice *bus = dev_get_parent(dev);
struct atmel_spi_priv *priv = dev_get_priv(bus);
struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
u32 cs = slave_plat->cs;
if (!dm_gpio_is_valid(&priv->cs_gpios[cs]))
return;
dm_gpio_set_value(&priv->cs_gpios[cs], 1);
#endif
}
static int atmel_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev_get_parent(dev);
struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
struct at91_spi *reg_base = bus_plat->regs;
u32 len_tx, len_rx, len;
u32 status;
const u8 *txp = dout;
u8 *rxp = din;
u8 value;
if (bitlen == 0)
goto out;
/*
* The controller can do non-multiple-of-8 bit
* transfers, but this driver currently doesn't support it.
*
* It's also not clear how such transfers are supposed to be
* represented as a stream of bytes...this is a limitation of
* the current SPI interface.
*/
if (bitlen % 8) {
/* Errors always terminate an ongoing transfer */
flags |= SPI_XFER_END;
goto out;
}
len = bitlen / 8;
/*
* The controller can do automatic CS control, but it is
* somewhat quirky, and it doesn't really buy us much anyway
* in the context of U-Boot.
*/
if (flags & SPI_XFER_BEGIN) {
atmel_spi_cs_activate(dev);
/*
* sometimes the RDR is not empty when we get here,
* in theory that should not happen, but it DOES happen.
* Read it here to be on the safe side.
* That also clears the OVRES flag. Required if the
* following loop exits due to OVRES!
*/
readl(&reg_base->rdr);
}
for (len_tx = 0, len_rx = 0; len_rx < len; ) {
status = readl(&reg_base->sr);
if (status & ATMEL_SPI_SR_OVRES)
return -1;
if ((len_tx < len) && (status & ATMEL_SPI_SR_TDRE)) {
if (txp)
value = *txp++;
else
value = 0;
writel(value, &reg_base->tdr);
len_tx++;
}
if (status & ATMEL_SPI_SR_RDRF) {
value = readl(&reg_base->rdr);
if (rxp)
*rxp++ = value;
len_rx++;
}
}
out:
if (flags & SPI_XFER_END) {
/*
* Wait until the transfer is completely done before
* we deactivate CS.
*/
wait_for_bit_le32(&reg_base->sr,
ATMEL_SPI_SR_TXEMPTY, true, 1000, false);
atmel_spi_cs_deactivate(dev);
}
return 0;
}
static int atmel_spi_set_speed(struct udevice *bus, uint speed)
{
struct atmel_spi_priv *priv = dev_get_priv(bus);
priv->freq = speed;
return 0;
}
static int atmel_spi_set_mode(struct udevice *bus, uint mode)
{
struct atmel_spi_priv *priv = dev_get_priv(bus);
priv->mode = mode;
return 0;
}
static const struct dm_spi_ops atmel_spi_ops = {
.claim_bus = atmel_spi_claim_bus,
.release_bus = atmel_spi_release_bus,
.xfer = atmel_spi_xfer,
.set_speed = atmel_spi_set_speed,
.set_mode = atmel_spi_set_mode,
/*
* cs_info is not needed, since we require all chip selects to be
* in the device tree explicitly
*/
};
static int atmel_spi_enable_clk(struct udevice *bus)
{
struct atmel_spi_priv *priv = dev_get_priv(bus);
struct clk clk;
ulong clk_rate;
int ret;
ret = clk_get_by_index(bus, 0, &clk);
if (ret)
return -EINVAL;
ret = clk_enable(&clk);
if (ret)
return ret;
clk_rate = clk_get_rate(&clk);
if (!clk_rate)
return -EINVAL;
priv->bus_clk_rate = clk_rate;
clk_free(&clk);
return 0;
}
static int atmel_spi_probe(struct udevice *bus)
{
struct atmel_spi_platdata *bus_plat = dev_get_platdata(bus);
int ret;
ret = atmel_spi_enable_clk(bus);
if (ret)
return ret;
bus_plat->regs = (struct at91_spi *)devfdt_get_addr(bus);
#ifdef CONFIG_DM_GPIO
struct atmel_spi_priv *priv = dev_get_priv(bus);
int i;
ret = gpio_request_list_by_name(bus, "cs-gpios", priv->cs_gpios,
ARRAY_SIZE(priv->cs_gpios), 0);
if (ret < 0) {
pr_err("Can't get %s gpios! Error: %d", bus->name, ret);
return ret;
}
for(i = 0; i < ARRAY_SIZE(priv->cs_gpios); i++) {
if (!dm_gpio_is_valid(&priv->cs_gpios[i]))
continue;
dm_gpio_set_dir_flags(&priv->cs_gpios[i],
GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
}
#endif
writel(ATMEL_SPI_CR_SWRST, &bus_plat->regs->cr);
return 0;
}
static const struct udevice_id atmel_spi_ids[] = {
{ .compatible = "atmel,at91rm9200-spi" },
{ }
};
U_BOOT_DRIVER(atmel_spi) = {
.name = "atmel_spi",
.id = UCLASS_SPI,
.of_match = atmel_spi_ids,
.ops = &atmel_spi_ops,
.platdata_auto_alloc_size = sizeof(struct atmel_spi_platdata),
.priv_auto_alloc_size = sizeof(struct atmel_spi_priv),
.probe = atmel_spi_probe,
};
#endif