/*
* I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c
* Begin write, send address byte(s), begin read, receive data bytes, end.
*/
int i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
{
u32 status;
u32 i = 0;
u8 *cur_data = data;
/* Check the hardware can handle the requested bytes */
if ((length < 0) || (length > ZYNQ_I2C_TRANSFERT_SIZE_MAX))
return -EINVAL;
/* Write the register address */
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_HOLD);
/*
* Temporarily disable restart (by clearing hold)
* It doesn't seem to work.
*/
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_RW |
ZYNQ_I2C_CONTROL_HOLD);
writel(0xFF, &zynq_i2c->interrupt_status);
while (alen--)
writel(addr >> (8*alen), &zynq_i2c->data);
writel(dev, &zynq_i2c->address);
/* Wait for the address to be sent */
if (!zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP)) {
/* Release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
return -ETIMEDOUT;
}
debug("Device acked address\n");
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_RW);
/* Start reading data */
writel(dev, &zynq_i2c->address);
writel(length, &zynq_i2c->transfer_size);
/* Wait for data */
do {
status = zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP |
ZYNQ_I2C_INTERRUPT_DATA);
if (!status) {
/* Release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
return -ETIMEDOUT;
}
debug("Read %d bytes\n",
length - readl(&zynq_i2c->transfer_size));
for (; i < length - readl(&zynq_i2c->transfer_size); i++)
*(cur_data++) = readl(&zynq_i2c->data);
} while (readl(&zynq_i2c->transfer_size) != 0);
/* All done... release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
#ifdef DEBUG
zynq_i2c_debug_status();
#endif
return 0;
}
/*
* I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c
* Begin write, send address byte(s), send data bytes, end.
*/
static int zynq_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
int alen, u8 *data, int length)
{
u8 *cur_data = data;
struct zynq_i2c_registers *zynq_i2c = i2c_select(adap);
/* Write the register address */
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_HOLD);
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_RW);
writel(0xFF, &zynq_i2c->interrupt_status);
writel(dev, &zynq_i2c->address);
if (alen) {
while (alen--)
writel(addr >> (8 * alen), &zynq_i2c->data);
/* Start the tranfer */
if (!zynq_i2c_wait(zynq_i2c, ZYNQ_I2C_INTERRUPT_COMP)) {
/* Release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
return -ETIMEDOUT;
}
debug("Device acked address\n");
}
while (length--) {
writel(*(cur_data++), &zynq_i2c->data);
if (readl(&zynq_i2c->transfer_size) == ZYNQ_I2C_FIFO_DEPTH) {
if (!zynq_i2c_wait(zynq_i2c, ZYNQ_I2C_INTERRUPT_COMP)) {
/* Release the bus */
clrbits_le32(&zynq_i2c->control,
ZYNQ_I2C_CONTROL_HOLD);
return -ETIMEDOUT;
}
}
}
/* All done... release the bus */
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
/* Wait for the address and data to be sent */
if (!zynq_i2c_wait(zynq_i2c, ZYNQ_I2C_INTERRUPT_COMP))
return -ETIMEDOUT;
return 0;
}
/*
* I2C probe called by cmd_i2c when doing 'i2c probe'.
* Begin read, nak data byte, end.
*/
int i2c_probe(u8 dev)
{
/* Attempt to read a byte */
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_RW);
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
writel(0xFF, &zynq_i2c->interrupt_status);
writel(dev, &zynq_i2c->address);
writel(1, &zynq_i2c->transfer_size);
return (zynq_i2c_wait(ZYNQ_I2C_INTERRUPT_COMP |
ZYNQ_I2C_INTERRUPT_NACK) &
ZYNQ_I2C_INTERRUPT_COMP) ? 0 : -ETIMEDOUT;
}
/*
* I2C probe called by cmd_i2c when doing 'i2c probe'.
* Begin read, nak data byte, end.
*/
static int zynq_i2c_probe(struct i2c_adapter *adap, u8 dev)
{
struct zynq_i2c_registers *zynq_i2c = i2c_select(adap);
/* Attempt to read a byte */
setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_CLR_FIFO |
ZYNQ_I2C_CONTROL_RW);
clrbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_HOLD);
writel(0xFF, &zynq_i2c->interrupt_status);
writel(dev, &zynq_i2c->address);
writel(1, &zynq_i2c->transfer_size);
return (zynq_i2c_wait(zynq_i2c, ZYNQ_I2C_INTERRUPT_COMP |
ZYNQ_I2C_INTERRUPT_NACK) &
ZYNQ_I2C_INTERRUPT_COMP) ? 0 : -ETIMEDOUT;
}