f-stack/dpdk/drivers/raw/ifpga/base/opae_i2c.c

514 lines
11 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2010-2019 Intel Corporation
*/
#include "opae_osdep.h"
#include "opae_i2c.h"
static int i2c_transfer(struct altera_i2c_dev *dev,
struct i2c_msg *msg, int num)
{
int ret, try;
for (ret = 0, try = 0; try < I2C_XFER_RETRY; try++) {
ret = dev->xfer(dev, msg, num);
if (ret != -EAGAIN)
break;
}
return ret;
}
/**
* i2c read function
*/
int i2c_read(struct altera_i2c_dev *dev, int flags, unsigned int slave_addr,
u32 offset, u8 *buf, u32 count)
{
u8 msgbuf[2];
int i = 0;
int ret;
pthread_mutex_lock(dev->mutex);
if (flags & I2C_FLAG_ADDR16)
msgbuf[i++] = offset >> 8;
msgbuf[i++] = offset;
struct i2c_msg msg[2] = {
{
.addr = slave_addr,
.flags = 0,
.len = i,
.buf = msgbuf,
},
{
.addr = slave_addr,
.flags = I2C_M_RD,
.len = count,
.buf = buf,
},
};
if (!dev->xfer) {
ret = -ENODEV;
goto exit;
}
ret = i2c_transfer(dev, msg, 2);
exit:
pthread_mutex_unlock(dev->mutex);
return ret;
}
int i2c_write(struct altera_i2c_dev *dev, int flags, unsigned int slave_addr,
u32 offset, u8 *buffer, int len)
{
struct i2c_msg msg;
u8 *buf;
int ret;
int i = 0;
pthread_mutex_lock(dev->mutex);
if (!dev->xfer) {
ret = -ENODEV;
goto exit;
}
buf = opae_malloc(I2C_MAX_OFFSET_LEN + len);
if (!buf) {
ret = -ENOMEM;
goto exit;
}
msg.addr = slave_addr;
msg.flags = 0;
msg.buf = buf;
if (flags & I2C_FLAG_ADDR16)
msg.buf[i++] = offset >> 8;
msg.buf[i++] = offset;
opae_memcpy(&msg.buf[i], buffer, len);
msg.len = i + len;
ret = i2c_transfer(dev, &msg, 1);
opae_free(buf);
exit:
pthread_mutex_unlock(dev->mutex);
return ret;
}
int i2c_read8(struct altera_i2c_dev *dev, unsigned int slave_addr, u32 offset,
u8 *buf, u32 count)
{
return i2c_read(dev, 0, slave_addr, offset, buf, count);
}
int i2c_read16(struct altera_i2c_dev *dev, unsigned int slave_addr, u32 offset,
u8 *buf, u32 count)
{
return i2c_read(dev, I2C_FLAG_ADDR16, slave_addr, offset,
buf, count);
}
int i2c_write8(struct altera_i2c_dev *dev, unsigned int slave_addr, u32 offset,
u8 *buf, u32 count)
{
return i2c_write(dev, 0, slave_addr, offset, buf, count);
}
int i2c_write16(struct altera_i2c_dev *dev, unsigned int slave_addr, u32 offset,
u8 *buf, u32 count)
{
return i2c_write(dev, I2C_FLAG_ADDR16, slave_addr, offset,
buf, count);
}
static void i2c_indirect_write(struct altera_i2c_dev *dev, u32 reg,
u32 value)
{
u64 ctrl;
ctrl = I2C_CTRL_W | (reg >> 2);
opae_writeq(value & I2C_WRITE_DATA_MASK, dev->base + I2C_WRITE);
opae_writeq(ctrl, dev->base + I2C_CTRL);
}
static u32 i2c_indirect_read(struct altera_i2c_dev *dev, u32 reg)
{
u64 tmp;
u64 ctrl;
u32 value;
ctrl = I2C_CTRL_R | (reg >> 2);
opae_writeq(ctrl, dev->base + I2C_CTRL);
/* FIXME: Read one more time to avoid HW timing issue. */
tmp = opae_readq(dev->base + I2C_READ);
tmp = opae_readq(dev->base + I2C_READ);
value = tmp & I2C_READ_DATA_MASK;
return value;
}
static void altera_i2c_transfer(struct altera_i2c_dev *dev, u32 data)
{
/*send STOP on last byte*/
if (dev->msg_len == 1)
data |= ALTERA_I2C_TFR_CMD_STO;
if (dev->msg_len > 0)
i2c_indirect_write(dev, ALTERA_I2C_TFR_CMD, data);
}
static void altera_i2c_disable(struct altera_i2c_dev *dev)
{
u32 val = i2c_indirect_read(dev, ALTERA_I2C_CTRL);
i2c_indirect_write(dev, ALTERA_I2C_CTRL, val&~ALTERA_I2C_CTRL_EN);
}
static void altera_i2c_enable(struct altera_i2c_dev *dev)
{
u32 val = i2c_indirect_read(dev, ALTERA_I2C_CTRL);
i2c_indirect_write(dev, ALTERA_I2C_CTRL, val | ALTERA_I2C_CTRL_EN);
}
static void altera_i2c_reset(struct altera_i2c_dev *dev)
{
altera_i2c_disable(dev);
altera_i2c_enable(dev);
}
static int altera_i2c_wait_core_idle(struct altera_i2c_dev *dev)
{
int retry = 0;
while (i2c_indirect_read(dev, ALTERA_I2C_STATUS)
& ALTERA_I2C_STAT_CORE) {
if (retry++ > ALTERA_I2C_TIMEOUT_US) {
dev_err(dev, "timeout: Core Status not IDLE...\n");
return -EBUSY;
}
udelay(1);
}
return 0;
}
static void altera_i2c_enable_interrupt(struct altera_i2c_dev *dev,
u32 mask, bool enable)
{
u32 status;
status = i2c_indirect_read(dev, ALTERA_I2C_ISER);
if (enable)
dev->isr_mask = status | mask;
else
dev->isr_mask = status&~mask;
i2c_indirect_write(dev, ALTERA_I2C_ISER, dev->isr_mask);
}
static void altera_i2c_interrupt_clear(struct altera_i2c_dev *dev, u32 mask)
{
u32 int_en;
int_en = i2c_indirect_read(dev, ALTERA_I2C_ISR);
i2c_indirect_write(dev, ALTERA_I2C_ISR, int_en | mask);
}
static void altera_i2c_read_rx_fifo(struct altera_i2c_dev *dev)
{
size_t rx_avail;
size_t bytes;
rx_avail = i2c_indirect_read(dev, ALTERA_I2C_RX_FIFO_LVL);
bytes = min(rx_avail, dev->msg_len);
while (bytes-- > 0) {
*dev->buf++ = i2c_indirect_read(dev, ALTERA_I2C_RX_DATA);
dev->msg_len--;
altera_i2c_transfer(dev, 0);
}
}
static void altera_i2c_stop(struct altera_i2c_dev *dev)
{
i2c_indirect_write(dev, ALTERA_I2C_TFR_CMD, ALTERA_I2C_TFR_CMD_STO);
}
static int altera_i2c_fill_tx_fifo(struct altera_i2c_dev *dev)
{
size_t tx_avail;
int bytes;
int ret;
tx_avail = dev->fifo_size -
i2c_indirect_read(dev, ALTERA_I2C_TC_FIFO_LVL);
bytes = min(tx_avail, dev->msg_len);
ret = dev->msg_len - bytes;
while (bytes-- > 0) {
altera_i2c_transfer(dev, *dev->buf++);
dev->msg_len--;
}
return ret;
}
static u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
{
return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
}
static int altera_i2c_wait_complete(struct altera_i2c_dev *dev,
u32 *status)
{
int retry = 0;
while (!((*status = i2c_indirect_read(dev, ALTERA_I2C_ISR))
& dev->isr_mask)) {
if (retry++ > ALTERA_I2C_TIMEOUT_US)
return -EBUSY;
udelay(1000);
}
return 0;
}
static bool altera_handle_i2c_status(struct altera_i2c_dev *dev, u32 status)
{
bool read, finish = false;
int ret;
read = (dev->msg->flags & I2C_M_RD) != 0;
if (status & ALTERA_I2C_ISR_ARB) {
altera_i2c_interrupt_clear(dev, ALTERA_I2C_ISR_ARB);
dev->msg_err = -EAGAIN;
finish = true;
} else if (status & ALTERA_I2C_ISR_NACK) {
dev_debug(dev, "could not get ACK\n");
dev->msg_err = -ENXIO;
altera_i2c_interrupt_clear(dev, ALTERA_I2C_ISR_NACK);
altera_i2c_stop(dev);
finish = true;
} else if (read && (status & ALTERA_I2C_ISR_RXOF)) {
/* RX FIFO Overflow */
altera_i2c_read_rx_fifo(dev);
altera_i2c_interrupt_clear(dev, ALTERA_I2C_ISER_RXOF_EN);
altera_i2c_stop(dev);
dev_err(dev, "error: RX FIFO overflow\n");
finish = true;
} else if (read && (status & ALTERA_I2C_ISR_RXRDY)) {
altera_i2c_read_rx_fifo(dev);
altera_i2c_interrupt_clear(dev, ALTERA_I2C_ISR_RXRDY);
if (!dev->msg_len)
finish = true;
} else if (!read && (status & ALTERA_I2C_ISR_TXRDY)) {
altera_i2c_interrupt_clear(dev, ALTERA_I2C_ISR_TXRDY);
if (dev->msg_len > 0)
altera_i2c_fill_tx_fifo(dev);
else
finish = true;
} else {
dev_err(dev, "unexpected status:0x%x\n", status);
altera_i2c_interrupt_clear(dev, ALTERA_I2C_ALL_IRQ);
}
if (finish) {
ret = altera_i2c_wait_core_idle(dev);
if (ret)
dev_err(dev, "message timeout\n");
altera_i2c_enable_interrupt(dev, ALTERA_I2C_ALL_IRQ, false);
altera_i2c_interrupt_clear(dev, ALTERA_I2C_ALL_IRQ);
dev_debug(dev, "message done\n");
}
return finish;
}
static bool altera_i2c_poll_status(struct altera_i2c_dev *dev)
{
u32 status;
bool finish = false;
int i = 0;
do {
if (altera_i2c_wait_complete(dev, &status)) {
dev_err(dev, "altera i2c wait complete timeout, status=0x%x\n",
status);
return -EBUSY;
}
finish = altera_handle_i2c_status(dev, status);
if (i++ > I2C_XFER_RETRY)
break;
} while (!finish);
return finish;
}
static int altera_i2c_xfer_msg(struct altera_i2c_dev *dev,
struct i2c_msg *msg)
{
u32 int_mask = ALTERA_I2C_ISR_RXOF |
ALTERA_I2C_ISR_ARB | ALTERA_I2C_ISR_NACK;
u8 addr = i2c_8bit_addr_from_msg(msg);
bool finish;
dev->msg = msg;
dev->msg_len = msg->len;
dev->buf = msg->buf;
dev->msg_err = 0;
altera_i2c_enable(dev);
/*make sure RX FIFO is emtry*/
do {
i2c_indirect_read(dev, ALTERA_I2C_RX_DATA);
} while (i2c_indirect_read(dev, ALTERA_I2C_RX_FIFO_LVL));
i2c_indirect_write(dev, ALTERA_I2C_TFR_CMD_RW_D,
ALTERA_I2C_TFR_CMD_STA | addr);
/*enable irq*/
if (msg->flags & I2C_M_RD) {
int_mask |= ALTERA_I2C_ISR_RXOF | ALTERA_I2C_ISR_RXRDY;
/* in polling mode, we should set this ISR register? */
altera_i2c_enable_interrupt(dev, int_mask, true);
altera_i2c_transfer(dev, 0);
} else {
int_mask |= ALTERA_I2C_ISR_TXRDY;
altera_i2c_enable_interrupt(dev, int_mask, true);
altera_i2c_fill_tx_fifo(dev);
}
finish = altera_i2c_poll_status(dev);
if (!finish) {
dev->msg_err = -ETIMEDOUT;
dev_err(dev, "%s: i2c transfer error\n", __func__);
}
altera_i2c_enable_interrupt(dev, int_mask, false);
if (i2c_indirect_read(dev, ALTERA_I2C_STATUS) & ALTERA_I2C_STAT_CORE)
dev_info(dev, "core not idle...\n");
altera_i2c_disable(dev);
return dev->msg_err;
}
static int altera_i2c_xfer(struct altera_i2c_dev *dev,
struct i2c_msg *msg, int num)
{
int ret = 0;
int i;
for (i = 0; i < num; i++, msg++) {
ret = altera_i2c_xfer_msg(dev, msg);
if (ret)
break;
}
return ret;
}
static void altera_i2c_hardware_init(struct altera_i2c_dev *dev)
{
u32 divisor = dev->i2c_clk / dev->bus_clk_rate;
u32 clk_mhz = dev->i2c_clk / 1000000;
u32 tmp = (ALTERA_I2C_THRESHOLD << ALTERA_I2C_CTRL_RXT_SHFT) |
(ALTERA_I2C_THRESHOLD << ALTERA_I2C_CTRL_TCT_SHFT);
u32 t_high, t_low;
if (dev->bus_clk_rate <= 100000) {
tmp &= ~ALTERA_I2C_CTRL_BSPEED;
/*standard mode SCL 50/50*/
t_high = divisor*1/2;
t_low = divisor*1/2;
} else {
tmp |= ALTERA_I2C_CTRL_BSPEED;
/*Fast mode SCL 33/66*/
t_high = divisor*1/3;
t_low = divisor*2/3;
}
i2c_indirect_write(dev, ALTERA_I2C_CTRL, tmp);
dev_info(dev, "%s: rate=%uHz per_clk=%uMHz -> ratio=1:%u\n",
__func__, dev->bus_clk_rate, clk_mhz, divisor);
/*reset the i2c*/
altera_i2c_reset(dev);
/*Set SCL high Time*/
i2c_indirect_write(dev, ALTERA_I2C_SCL_HIGH, t_high);
/*Set SCL low time*/
i2c_indirect_write(dev, ALTERA_I2C_SCL_LOW, t_low);
/*Set SDA Hold time, 300ms*/
i2c_indirect_write(dev, ALTERA_I2C_SDA_HOLD, (300*clk_mhz)/1000);
altera_i2c_enable_interrupt(dev, ALTERA_I2C_ALL_IRQ, false);
}
struct altera_i2c_dev *altera_i2c_probe(void *base)
{
struct altera_i2c_dev *dev;
dev = opae_malloc(sizeof(*dev));
if (!dev)
return NULL;
dev->base = (u8 *)base;
dev->i2c_param.info = opae_readq(dev->base + I2C_PARAM);
if (dev->i2c_param.devid != 0xEE011) {
dev_err(dev, "find a invalid i2c master\n");
return NULL;
}
dev->fifo_size = dev->i2c_param.fifo_depth;
if (dev->i2c_param.max_req == ALTERA_I2C_100KHZ)
dev->bus_clk_rate = 100000;
else if (dev->i2c_param.max_req == ALTERA_I2C_400KHZ)
/* i2c bus clk 400KHz*/
dev->bus_clk_rate = 400000;
/* i2c input clock for vista creek is 100MHz */
dev->i2c_clk = dev->i2c_param.ref_clk * 1000000;
dev->xfer = altera_i2c_xfer;
if (pthread_mutex_init(&dev->lock, NULL))
return NULL;
dev->mutex = &dev->lock;
altera_i2c_hardware_init(dev);
return dev;
}
void altera_i2c_remove(struct altera_i2c_dev *dev)
{
if (dev) {
pthread_mutex_destroy(&dev->lock);
altera_i2c_disable(dev);
opae_free(dev);
}
}