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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2008, Guennadi Liakhovetski <lg@denx.de>
*/
#include <common.h>
#include <dm.h>
#include <log.h>
#include <malloc.h>
#include <spi.h>
#include <dm/device_compat.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <asm/io.h>
#include <asm/gpio.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/clock.h>
#include <asm/mach-imx/spi.h>
DECLARE_GLOBAL_DATA_PTR;
#ifdef CONFIG_MX27
/* i.MX27 has a completely wrong register layout and register definitions in the
* datasheet, the correct one is in the Freescale's Linux driver */
#error "i.MX27 CSPI not supported due to drastic differences in register definitions" \
"See linux mxc_spi driver from Freescale for details."
#endif
__weak int board_spi_cs_gpio(unsigned bus, unsigned cs)
{
return -1;
}
#define OUT MXC_GPIO_DIRECTION_OUT
#define reg_read readl
#define reg_write(a, v) writel(v, a)
#if !defined(CONFIG_SYS_SPI_MXC_WAIT)
#define CONFIG_SYS_SPI_MXC_WAIT (CONFIG_SYS_HZ/100) /* 10 ms */
#endif
#define MAX_CS_COUNT 4
struct mxc_spi_slave {
struct spi_slave slave;
unsigned long base;
u32 ctrl_reg;
#if defined(MXC_ECSPI)
u32 cfg_reg;
#endif
int gpio;
int ss_pol;
unsigned int max_hz;
unsigned int mode;
struct gpio_desc ss;
struct gpio_desc cs_gpios[MAX_CS_COUNT];
struct udevice *dev;
};
static inline struct mxc_spi_slave *to_mxc_spi_slave(struct spi_slave *slave)
{
return container_of(slave, struct mxc_spi_slave, slave);
}
static void mxc_spi_cs_activate(struct mxc_spi_slave *mxcs)
{
#if CONFIG_IS_ENABLED(DM_SPI)
struct udevice *dev = mxcs->dev;
struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
u32 cs = slave_plat->cs;
if (!dm_gpio_is_valid(&mxcs->cs_gpios[cs]))
return;
dm_gpio_set_value(&mxcs->cs_gpios[cs], 1);
#else
if (mxcs->gpio > 0)
gpio_set_value(mxcs->gpio, mxcs->ss_pol);
#endif
}
static void mxc_spi_cs_deactivate(struct mxc_spi_slave *mxcs)
{
#if CONFIG_IS_ENABLED(DM_SPI)
struct udevice *dev = mxcs->dev;
struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
u32 cs = slave_plat->cs;
if (!dm_gpio_is_valid(&mxcs->cs_gpios[cs]))
return;
dm_gpio_set_value(&mxcs->cs_gpios[cs], 0);
#else
if (mxcs->gpio > 0)
gpio_set_value(mxcs->gpio, !(mxcs->ss_pol));
#endif
}
u32 get_cspi_div(u32 div)
{
int i;
for (i = 0; i < 8; i++) {
if (div <= (4 << i))
return i;
}
return i;
}
#ifdef MXC_CSPI
static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs)
{
unsigned int ctrl_reg;
u32 clk_src;
u32 div;
unsigned int max_hz = mxcs->max_hz;
unsigned int mode = mxcs->mode;
clk_src = mxc_get_clock(MXC_CSPI_CLK);
div = DIV_ROUND_UP(clk_src, max_hz);
div = get_cspi_div(div);
debug("clk %d Hz, div %d, real clk %d Hz\n",
max_hz, div, clk_src / (4 << div));
ctrl_reg = MXC_CSPICTRL_CHIPSELECT(cs) |
MXC_CSPICTRL_BITCOUNT(MXC_CSPICTRL_MAXBITS) |
MXC_CSPICTRL_DATARATE(div) |
MXC_CSPICTRL_EN |
#ifdef CONFIG_MX35
MXC_CSPICTRL_SSCTL |
#endif
MXC_CSPICTRL_MODE;
if (mode & SPI_CPHA)
ctrl_reg |= MXC_CSPICTRL_PHA;
if (mode & SPI_CPOL)
ctrl_reg |= MXC_CSPICTRL_POL;
if (mode & SPI_CS_HIGH)
ctrl_reg |= MXC_CSPICTRL_SSPOL;
mxcs->ctrl_reg = ctrl_reg;
return 0;
}
#endif
#ifdef MXC_ECSPI
static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs)
{
u32 clk_src = mxc_get_clock(MXC_CSPI_CLK);
s32 reg_ctrl, reg_config;
u32 ss_pol = 0, sclkpol = 0, sclkpha = 0, sclkctl = 0;
u32 pre_div = 0, post_div = 0;
struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
unsigned int max_hz = mxcs->max_hz;
unsigned int mode = mxcs->mode;
/*
* Reset SPI and set all CSs to master mode, if toggling
* between slave and master mode we might see a glitch
* on the clock line
*/
reg_ctrl = MXC_CSPICTRL_MODE_MASK;
reg_write(&regs->ctrl, reg_ctrl);
reg_ctrl |= MXC_CSPICTRL_EN;
reg_write(&regs->ctrl, reg_ctrl);
if (clk_src > max_hz) {
pre_div = (clk_src - 1) / max_hz;
/* fls(1) = 1, fls(0x80000000) = 32, fls(16) = 5 */
post_div = fls(pre_div);
if (post_div > 4) {
post_div -= 4;
if (post_div >= 16) {
printf("Error: no divider for the freq: %d\n",
max_hz);
return -1;
}
pre_div >>= post_div;
} else {
post_div = 0;
}
}
debug("pre_div = %d, post_div=%d\n", pre_div, post_div);
reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_SELCHAN(3)) |
MXC_CSPICTRL_SELCHAN(cs);
reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_PREDIV(0x0F)) |
MXC_CSPICTRL_PREDIV(pre_div);
reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_POSTDIV(0x0F)) |
MXC_CSPICTRL_POSTDIV(post_div);
if (mode & SPI_CS_HIGH)
ss_pol = 1;
if (mode & SPI_CPOL) {
sclkpol = 1;
sclkctl = 1;
}
if (mode & SPI_CPHA)
sclkpha = 1;
reg_config = reg_read(&regs->cfg);
/*
* Configuration register setup
* The MX51 supports different setup for each SS
*/
reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_SSPOL))) |
(ss_pol << (cs + MXC_CSPICON_SSPOL));
reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_POL))) |
(sclkpol << (cs + MXC_CSPICON_POL));
reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_CTL))) |
(sclkctl << (cs + MXC_CSPICON_CTL));
reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_PHA))) |
(sclkpha << (cs + MXC_CSPICON_PHA));
debug("reg_ctrl = 0x%x\n", reg_ctrl);
reg_write(&regs->ctrl, reg_ctrl);
debug("reg_config = 0x%x\n", reg_config);
reg_write(&regs->cfg, reg_config);
/* save config register and control register */
mxcs->ctrl_reg = reg_ctrl;
mxcs->cfg_reg = reg_config;
/* clear interrupt reg */
reg_write(&regs->intr, 0);
reg_write(&regs->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF);
return 0;
}
#endif
int spi_xchg_single(struct mxc_spi_slave *mxcs, unsigned int bitlen,
const u8 *dout, u8 *din, unsigned long flags)
{
int nbytes = DIV_ROUND_UP(bitlen, 8);
u32 data, cnt, i;
struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
u32 ts;
int status;
debug("%s: bitlen %d dout 0x%lx din 0x%lx\n",
__func__, bitlen, (ulong)dout, (ulong)din);
mxcs->ctrl_reg = (mxcs->ctrl_reg &
~MXC_CSPICTRL_BITCOUNT(MXC_CSPICTRL_MAXBITS)) |
MXC_CSPICTRL_BITCOUNT(bitlen - 1);
reg_write(&regs->ctrl, mxcs->ctrl_reg | MXC_CSPICTRL_EN);
#ifdef MXC_ECSPI
reg_write(&regs->cfg, mxcs->cfg_reg);
#endif
/* Clear interrupt register */
reg_write(&regs->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF);
/*
* The SPI controller works only with words,
* check if less than a word is sent.
* Access to the FIFO is only 32 bit
*/
if (bitlen % 32) {
data = 0;
cnt = (bitlen % 32) / 8;
if (dout) {
for (i = 0; i < cnt; i++) {
data = (data << 8) | (*dout++ & 0xFF);
}
}
debug("Sending SPI 0x%x\n", data);
reg_write(&regs->txdata, data);
nbytes -= cnt;
}
data = 0;
while (nbytes > 0) {
data = 0;
if (dout) {
/* Buffer is not 32-bit aligned */
if ((unsigned long)dout & 0x03) {
data = 0;
for (i = 0; i < 4; i++)
data = (data << 8) | (*dout++ & 0xFF);
} else {
data = *(u32 *)dout;
data = cpu_to_be32(data);
dout += 4;
}
}
debug("Sending SPI 0x%x\n", data);
reg_write(&regs->txdata, data);
nbytes -= 4;
}
/* FIFO is written, now starts the transfer setting the XCH bit */
reg_write(&regs->ctrl, mxcs->ctrl_reg |
MXC_CSPICTRL_EN | MXC_CSPICTRL_XCH);
ts = get_timer(0);
status = reg_read(&regs->stat);
/* Wait until the TC (Transfer completed) bit is set */
while ((status & MXC_CSPICTRL_TC) == 0) {
if (get_timer(ts) > CONFIG_SYS_SPI_MXC_WAIT) {
printf("spi_xchg_single: Timeout!\n");
return -1;
}
status = reg_read(&regs->stat);
}
/* Transfer completed, clear any pending request */
reg_write(&regs->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF);
nbytes = DIV_ROUND_UP(bitlen, 8);
cnt = nbytes % 32;
if (bitlen % 32) {
data = reg_read(&regs->rxdata);
cnt = (bitlen % 32) / 8;
data = cpu_to_be32(data) >> ((sizeof(data) - cnt) * 8);
debug("SPI Rx unaligned: 0x%x\n", data);
if (din) {
memcpy(din, &data, cnt);
din += cnt;
}
nbytes -= cnt;
}
while (nbytes > 0) {
u32 tmp;
tmp = reg_read(&regs->rxdata);
data = cpu_to_be32(tmp);
debug("SPI Rx: 0x%x 0x%x\n", tmp, data);
cnt = min_t(u32, nbytes, sizeof(data));
if (din) {
memcpy(din, &data, cnt);
din += cnt;
}
nbytes -= cnt;
}
return 0;
}
static int mxc_spi_xfer_internal(struct mxc_spi_slave *mxcs,
unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
int n_bytes = DIV_ROUND_UP(bitlen, 8);
int n_bits;
int ret;
u32 blk_size;
u8 *p_outbuf = (u8 *)dout;
u8 *p_inbuf = (u8 *)din;
if (!mxcs)
return -EINVAL;
if (flags & SPI_XFER_BEGIN)
mxc_spi_cs_activate(mxcs);
while (n_bytes > 0) {
if (n_bytes < MAX_SPI_BYTES)
blk_size = n_bytes;
else
blk_size = MAX_SPI_BYTES;
n_bits = blk_size * 8;
ret = spi_xchg_single(mxcs, n_bits, p_outbuf, p_inbuf, 0);
if (ret)
return ret;
if (dout)
p_outbuf += blk_size;
if (din)
p_inbuf += blk_size;
n_bytes -= blk_size;
}
if (flags & SPI_XFER_END) {
mxc_spi_cs_deactivate(mxcs);
}
return 0;
}
static int mxc_spi_claim_bus_internal(struct mxc_spi_slave *mxcs, int cs)
{
struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
int ret;
reg_write(&regs->rxdata, 1);
udelay(1);
ret = spi_cfg_mxc(mxcs, cs);
if (ret) {
printf("mxc_spi: cannot setup SPI controller\n");
return ret;
}
reg_write(&regs->period, MXC_CSPIPERIOD_32KHZ);
reg_write(&regs->intr, 0);
return 0;
}
#if !CONFIG_IS_ENABLED(DM_SPI)
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
return mxc_spi_xfer_internal(mxcs, bitlen, dout, din, flags);
}
/*
* Some SPI devices require active chip-select over multiple
* transactions, we achieve this using a GPIO. Still, the SPI
* controller has to be configured to use one of its own chipselects.
* To use this feature you have to implement board_spi_cs_gpio() to assign
* a gpio value for each cs (-1 if cs doesn't need to use gpio).
* You must use some unused on this SPI controller cs between 0 and 3.
*/
static int setup_cs_gpio(struct mxc_spi_slave *mxcs,
unsigned int bus, unsigned int cs)
{
int ret;
mxcs->gpio = board_spi_cs_gpio(bus, cs);
if (mxcs->gpio == -1)
return 0;
gpio_request(mxcs->gpio, "spi-cs");
ret = gpio_direction_output(mxcs->gpio, !(mxcs->ss_pol));
if (ret) {
printf("mxc_spi: cannot setup gpio %d\n", mxcs->gpio);
return -EINVAL;
}
return 0;
}
static unsigned long spi_bases[] = {
MXC_SPI_BASE_ADDRESSES
};
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct mxc_spi_slave *mxcs;
int ret;
if (bus >= ARRAY_SIZE(spi_bases))
return NULL;
if (max_hz == 0) {
printf("Error: desired clock is 0\n");
return NULL;
}
mxcs = spi_alloc_slave(struct mxc_spi_slave, bus, cs);
if (!mxcs) {
puts("mxc_spi: SPI Slave not allocated !\n");
return NULL;
}
mxcs->ss_pol = (mode & SPI_CS_HIGH) ? 1 : 0;
ret = setup_cs_gpio(mxcs, bus, cs);
if (ret < 0) {
free(mxcs);
return NULL;
}
mxcs->base = spi_bases[bus];
mxcs->max_hz = max_hz;
mxcs->mode = mode;
return &mxcs->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
free(mxcs);
}
int spi_claim_bus(struct spi_slave *slave)
{
struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
return mxc_spi_claim_bus_internal(mxcs, slave->cs);
}
void spi_release_bus(struct spi_slave *slave)
{
/* TODO: Shut the controller down */
}
#else
static int mxc_spi_probe(struct udevice *bus)
{
struct mxc_spi_slave *mxcs = dev_get_platdata(bus);
int node = dev_of_offset(bus);
const void *blob = gd->fdt_blob;
int ret;
int i;
ret = gpio_request_list_by_name(bus, "cs-gpios", mxcs->cs_gpios,
ARRAY_SIZE(mxcs->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(mxcs->cs_gpios); i++) {
if (!dm_gpio_is_valid(&mxcs->cs_gpios[i]))
continue;
ret = dm_gpio_set_dir_flags(&mxcs->cs_gpios[i],
GPIOD_IS_OUT | GPIOD_ACTIVE_LOW);
if (ret) {
dev_err(bus, "Setting cs %d error\n", i);
return ret;
}
}
mxcs->base = devfdt_get_addr(bus);
if (mxcs->base == FDT_ADDR_T_NONE)
return -ENODEV;
mxcs->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency",
20000000);
return 0;
}
static int mxc_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct mxc_spi_slave *mxcs = dev_get_platdata(dev->parent);
return mxc_spi_xfer_internal(mxcs, bitlen, dout, din, flags);
}
static int mxc_spi_claim_bus(struct udevice *dev)
{
struct mxc_spi_slave *mxcs = dev_get_platdata(dev->parent);
struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
mxcs->dev = dev;
return mxc_spi_claim_bus_internal(mxcs, slave_plat->cs);
}
static int mxc_spi_release_bus(struct udevice *dev)
{
return 0;
}
static int mxc_spi_set_speed(struct udevice *bus, uint speed)
{
/* Nothing to do */
return 0;
}
static int mxc_spi_set_mode(struct udevice *bus, uint mode)
{
struct mxc_spi_slave *mxcs = dev_get_platdata(bus);
mxcs->mode = mode;
mxcs->ss_pol = (mode & SPI_CS_HIGH) ? 1 : 0;
return 0;
}
static const struct dm_spi_ops mxc_spi_ops = {
.claim_bus = mxc_spi_claim_bus,
.release_bus = mxc_spi_release_bus,
.xfer = mxc_spi_xfer,
.set_speed = mxc_spi_set_speed,
.set_mode = mxc_spi_set_mode,
};
static const struct udevice_id mxc_spi_ids[] = {
{ .compatible = "fsl,imx51-ecspi" },
{ }
};
U_BOOT_DRIVER(mxc_spi) = {
.name = "mxc_spi",
.id = UCLASS_SPI,
.of_match = mxc_spi_ids,
.ops = &mxc_spi_ops,
.platdata_auto_alloc_size = sizeof(struct mxc_spi_slave),
.probe = mxc_spi_probe,
};
#endif