u-boot/drivers/i2c/tegra186_bpmp_i2c.c
Jean-Jacques Hiblot 22ecff594d i2c: tegra: Fix regression by implementing a dummy probe_chip() callback
Commit f32a8007ef ("dm: i2c: Make i2c_get_chip_for_busnum() fail if the
chip is not detected") introduced a regression for the NVIDIA Jetson TX2.

For some reason the xfer callback of the tegra i2c driver doesn't support
probing the I2C devices with a 0-length message.
Fixing the regression by providing a dummy implementation of probe_chip()
that does nothing.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
2018-12-12 06:06:14 +01:00

125 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2016, NVIDIA CORPORATION.
*/
#include <common.h>
#include <dm.h>
#include <i2c.h>
#include <misc.h>
#include <asm/arch-tegra/bpmp_abi.h>
DECLARE_GLOBAL_DATA_PTR;
struct tegra186_bpmp_i2c {
uint32_t bpmp_bus_id;
};
static inline void serialize_u16(uint8_t **p, uint16_t val)
{
(*p)[0] = val & 0xff;
(*p)[1] = val >> 8;
(*p) += 2;
}
/* These just happen to have the same values as I2C_M_* and SERIALI2C_* */
#define SUPPORTED_FLAGS \
(I2C_M_TEN | \
I2C_M_RD | \
I2C_M_STOP | \
I2C_M_NOSTART | \
I2C_M_REV_DIR_ADDR | \
I2C_M_IGNORE_NAK | \
I2C_M_NO_RD_ACK | \
I2C_M_RECV_LEN)
static int tegra186_bpmp_i2c_xfer(struct udevice *dev, struct i2c_msg *msg,
int nmsgs)
{
struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
struct mrq_i2c_request req;
struct mrq_i2c_response resp;
uint8_t *p;
int left, i, ret;
req.cmd = CMD_I2C_XFER;
req.xfer.bus_id = priv->bpmp_bus_id;
p = &req.xfer.data_buf[0];
left = ARRAY_SIZE(req.xfer.data_buf);
for (i = 0; i < nmsgs; i++) {
int len = 6;
if (!(msg[i].flags & I2C_M_RD))
len += msg[i].len;
if ((len >= BIT(16)) || (len > left))
return -ENOSPC;
if (msg[i].flags & ~SUPPORTED_FLAGS)
return -EINVAL;
serialize_u16(&p, msg[i].addr);
serialize_u16(&p, msg[i].flags);
serialize_u16(&p, msg[i].len);
if (!(msg[i].flags & I2C_M_RD)) {
memcpy(p, msg[i].buf, msg[i].len);
p += msg[i].len;
}
}
req.xfer.data_size = p - &req.xfer.data_buf[0];
ret = misc_call(dev->parent, MRQ_I2C, &req, sizeof(req), &resp,
sizeof(resp));
if (ret < 0)
return ret;
p = &resp.xfer.data_buf[0];
left = resp.xfer.data_size;
if (left > ARRAY_SIZE(resp.xfer.data_buf))
return -EINVAL;
for (i = 0; i < nmsgs; i++) {
if (msg[i].flags & I2C_M_RD) {
memcpy(msg[i].buf, p, msg[i].len);
p += msg[i].len;
}
}
return 0;
}
static int tegra186_bpmp_probe_chip(struct udevice *bus, uint chip_addr,
uint chip_flags)
{
return 0;
}
static int tegra186_bpmp_i2c_probe(struct udevice *dev)
{
struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
priv->bpmp_bus_id = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
"nvidia,bpmp-bus-id", U32_MAX);
if (priv->bpmp_bus_id == U32_MAX) {
debug("%s: could not parse nvidia,bpmp-bus-id\n", __func__);
return -EINVAL;
}
return 0;
}
static const struct dm_i2c_ops tegra186_bpmp_i2c_ops = {
.xfer = tegra186_bpmp_i2c_xfer,
.probe_chip = tegra186_bpmp_probe_chip,
};
static const struct udevice_id tegra186_bpmp_i2c_ids[] = {
{ .compatible = "nvidia,tegra186-bpmp-i2c" },
{ }
};
U_BOOT_DRIVER(i2c_gpio) = {
.name = "tegra186_bpmp_i2c",
.id = UCLASS_I2C,
.of_match = tegra186_bpmp_i2c_ids,
.probe = tegra186_bpmp_i2c_probe,
.priv_auto_alloc_size = sizeof(struct tegra186_bpmp_i2c),
.ops = &tegra186_bpmp_i2c_ops,
};