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/* SPDX-License-Identifier: MIT */
#include "adt.h"
#include "i2c.h"
#include "malloc.h"
#include "pmgr.h"
#include "types.h"
#include "utils.h"
#define PASEMI_FIFO_TX 0x00
#define PASEMI_TX_FLAG_READ BIT(10)
#define PASEMI_TX_FLAG_STOP BIT(9)
#define PASEMI_TX_FLAG_START BIT(8)
#define PASEMI_FIFO_RX 0x04
#define PASEMI_RX_FLAG_EMPTY BIT(8)
#define PASEMI_STATUS 0x14
#define PASEMI_STATUS_XFER_BUSY BIT(28)
#define PASEMI_STATUS_XFER_ENDED BIT(27)
#define PASEMI_CONTROL 0x1c
#define PASEMI_CONTROL_CLEAR_RX BIT(10)
#define PASEMI_CONTROL_CLEAR_TX BIT(9)
struct i2c_dev {
uintptr_t base;
};
i2c_dev_t *i2c_init(const char *adt_node)
{
int adt_path[8];
int adt_offset;
adt_offset = adt_path_offset_trace(adt, adt_node, adt_path);
if (adt_offset < 0) {
printf("i2c: Error getting %s node\n", adt_node);
return NULL;
}
u64 base;
if (adt_get_reg(adt, adt_path, "reg", 0, &base, NULL) < 0) {
printf("i2c: Error getting %s regs\n", adt_node);
return NULL;
}
if (pmgr_adt_power_enable(adt_node)) {
printf("i2c: Error enabling power for %s\n", adt_node);
return NULL;
}
i2c_dev_t *dev = malloc(sizeof(*dev));
if (!dev)
return NULL;
dev->base = base;
return dev;
}
void i2c_shutdown(i2c_dev_t *dev)
{
free(dev);
}
static void i2c_clear_fifos(i2c_dev_t *dev)
{
set32(dev->base + PASEMI_CONTROL, PASEMI_CONTROL_CLEAR_TX | PASEMI_CONTROL_CLEAR_RX);
}
static void i2c_clear_status(i2c_dev_t *dev)
{
write32(dev->base + PASEMI_STATUS, 0xffffffff);
}
static void i2c_xfer_start_read(i2c_dev_t *dev, u8 addr, size_t len)
{
write32(dev->base + PASEMI_FIFO_TX, PASEMI_TX_FLAG_START | (addr << 1) | 1);
write32(dev->base + PASEMI_FIFO_TX, PASEMI_TX_FLAG_READ | PASEMI_TX_FLAG_STOP | len);
}
static size_t i2c_xfer_read(i2c_dev_t *dev, u8 *bfr, size_t len)
{
for (size_t i = 0; i < len; ++i) {
u32 timeout = 5000;
u32 val;
do {
val = read32(dev->base + PASEMI_FIFO_RX);
if (!(val & PASEMI_RX_FLAG_EMPTY))
break;
udelay(10);
} while (--timeout);
if (val & PASEMI_RX_FLAG_EMPTY) {
printf("i2c: timeout while reading (got %lu, expected %lu bytes)\n", i, len);
return i;
}
bfr[i] = val;
}
return len;
}
static int i2c_xfer_write(i2c_dev_t *dev, u8 addr, u32 start, u32 stop, const u8 *bfr, size_t len)
{
if (start)
write32(dev->base + PASEMI_FIFO_TX, PASEMI_TX_FLAG_START | (addr << 1));
for (size_t i = 0; i < len; ++i) {
u32 data = bfr[i];
if (i == (len - 1) && stop)
data |= PASEMI_TX_FLAG_STOP;
write32(dev->base + PASEMI_FIFO_TX, data);
}
if (!stop)
return 0;
if (poll32(dev->base + PASEMI_STATUS, PASEMI_STATUS_XFER_BUSY, 0, 50000)) {
printf(
"i2c: timeout while waiting for PASEMI_STATUS_XFER_BUSY to clear after write xfer\n");
return -1;
}
return 0;
}
int i2c_smbus_read(i2c_dev_t *dev, u8 addr, u8 reg, u8 *bfr, size_t len)
{
int ret = -1;
i2c_clear_fifos(dev);
i2c_clear_status(dev);
if (i2c_xfer_write(dev, addr, 1, 0, ®, 1))
goto err;
i2c_xfer_start_read(dev, addr, len + 1);
u8 len_reply;
if (i2c_xfer_read(dev, &len_reply, 1) != 1)
goto err;
if (len_reply < len)
printf("i2c: want to read %ld bytes from addr %d but can only read %d\n", len, addr,
len_reply);
if (len_reply > len)
printf("i2c: want to read %ld bytes from addr %d but device wants to send %d\n", len, addr,
len_reply);
ret = i2c_xfer_read(dev, bfr, min(len, len_reply));
err:
if (poll32(dev->base + PASEMI_STATUS, PASEMI_STATUS_XFER_BUSY, 0, 50000)) {
printf("i2c: timeout while waiting for PASEMI_STATUS_XFER_BUSY to clear after read xfer\n");
return -1;
}
return ret;
}
int i2c_smbus_write(i2c_dev_t *dev, u8 addr, u8 reg, const u8 *bfr, size_t len)
{
i2c_clear_fifos(dev);
i2c_clear_status(dev);
if (i2c_xfer_write(dev, addr, 1, 0, ®, 1))
return -1;
u8 len_send = len;
if (i2c_xfer_write(dev, addr, 0, 0, &len_send, 1))
return -1;
if (i2c_xfer_write(dev, addr, 0, 1, bfr, len))
return -1;
return len_send;
}
int i2c_smbus_read32(i2c_dev_t *dev, u8 addr, u8 reg, u32 *val)
{
u8 bfr[4];
if (i2c_smbus_read(dev, addr, reg, bfr, 4) != 4)
return -1;
*val = (bfr[0]) | (bfr[1] << 8) | (bfr[2] << 16) | (bfr[3] << 24);
return 0;
}
int i2c_smbus_read16(i2c_dev_t *dev, u8 addr, u8 reg, u16 *val)
{
u8 bfr[2];
if (i2c_smbus_read(dev, addr, reg, bfr, 2) != 2)
return -1;
*val = (bfr[0]) | (bfr[1] << 8);
return 0;
}
int i2c_smbus_write32(i2c_dev_t *dev, u8 addr, u8 reg, u32 val)
{
u8 bfr[4];
bfr[0] = val;
bfr[1] = val >> 8;
bfr[2] = val >> 16;
bfr[3] = val >> 24;
return i2c_smbus_write(dev, addr, reg, bfr, 4);
}
int i2c_smbus_read8(i2c_dev_t *dev, u8 addr, u8 reg, u8 *val)
{
if (i2c_smbus_read(dev, addr, reg, val, 1) != 1)
return -1;
return 0;
}
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