347 lines
8.5 KiB
C
347 lines
8.5 KiB
C
/*
|
|
* drivers/i2c/busses/i2c-tegra-bpmp.c
|
|
*
|
|
* Copyright (c) 2016 NVIDIA Corporation. All rights reserved.
|
|
*
|
|
* Author: Shardar Shariff Md <smohammed@nvidia.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms and conditions of the GNU General Public License,
|
|
* version 2, as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
|
* more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <linux/err.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of_device.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/pm_runtime.h>
|
|
|
|
#include <soc/tegra/bpmp-abi.h>
|
|
#include <soc/tegra/bpmp.h>
|
|
|
|
/*
|
|
* Serialized I2C message header size is 6 bytes and includes address, flags
|
|
* and length
|
|
*/
|
|
#define SERIALI2C_HDR_SIZE 6
|
|
|
|
struct tegra_bpmp_i2c {
|
|
struct i2c_adapter adapter;
|
|
struct device *dev;
|
|
|
|
struct tegra_bpmp *bpmp;
|
|
unsigned int bus;
|
|
};
|
|
|
|
/*
|
|
* Linux flags are translated to BPMP defined I2C flags that are used in BPMP
|
|
* firmware I2C driver to avoid any issues in future if Linux I2C flags are
|
|
* changed.
|
|
*/
|
|
static int tegra_bpmp_xlate_flags(u16 flags, u16 *out)
|
|
{
|
|
if (flags & I2C_M_TEN) {
|
|
*out |= SERIALI2C_TEN;
|
|
flags &= ~I2C_M_TEN;
|
|
}
|
|
|
|
if (flags & I2C_M_RD) {
|
|
*out |= SERIALI2C_RD;
|
|
flags &= ~I2C_M_RD;
|
|
}
|
|
|
|
if (flags & I2C_M_STOP) {
|
|
*out |= SERIALI2C_STOP;
|
|
flags &= ~I2C_M_STOP;
|
|
}
|
|
|
|
if (flags & I2C_M_NOSTART) {
|
|
*out |= SERIALI2C_NOSTART;
|
|
flags &= ~I2C_M_NOSTART;
|
|
}
|
|
|
|
if (flags & I2C_M_REV_DIR_ADDR) {
|
|
*out |= SERIALI2C_REV_DIR_ADDR;
|
|
flags &= ~I2C_M_REV_DIR_ADDR;
|
|
}
|
|
|
|
if (flags & I2C_M_IGNORE_NAK) {
|
|
*out |= SERIALI2C_IGNORE_NAK;
|
|
flags &= ~I2C_M_IGNORE_NAK;
|
|
}
|
|
|
|
if (flags & I2C_M_NO_RD_ACK) {
|
|
*out |= SERIALI2C_NO_RD_ACK;
|
|
flags &= ~I2C_M_NO_RD_ACK;
|
|
}
|
|
|
|
if (flags & I2C_M_RECV_LEN) {
|
|
*out |= SERIALI2C_RECV_LEN;
|
|
flags &= ~I2C_M_RECV_LEN;
|
|
}
|
|
|
|
return (flags != 0) ? -EINVAL : 0;
|
|
}
|
|
|
|
/**
|
|
* The serialized I2C format is simply the following:
|
|
* [addr little-endian][flags little-endian][len little-endian][data if write]
|
|
* [addr little-endian][flags little-endian][len little-endian][data if write]
|
|
* ...
|
|
*
|
|
* The flags are translated from Linux kernel representation to seriali2c
|
|
* representation. Any undefined flag being set causes an error.
|
|
*
|
|
* The data is there only for writes. Reads have the data transferred in the
|
|
* other direction, and thus data is not present.
|
|
*
|
|
* See deserialize_i2c documentation for the data format in the other direction.
|
|
*/
|
|
static int tegra_bpmp_serialize_i2c_msg(struct tegra_bpmp_i2c *i2c,
|
|
struct mrq_i2c_request *request,
|
|
struct i2c_msg *msgs,
|
|
unsigned int num)
|
|
{
|
|
char *buf = request->xfer.data_buf;
|
|
unsigned int i, j, pos = 0;
|
|
int err;
|
|
|
|
for (i = 0; i < num; i++) {
|
|
struct i2c_msg *msg = &msgs[i];
|
|
u16 flags = 0;
|
|
|
|
err = tegra_bpmp_xlate_flags(msg->flags, &flags);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
buf[pos++] = msg->addr & 0xff;
|
|
buf[pos++] = (msg->addr & 0xff00) >> 8;
|
|
buf[pos++] = flags & 0xff;
|
|
buf[pos++] = (flags & 0xff00) >> 8;
|
|
buf[pos++] = msg->len & 0xff;
|
|
buf[pos++] = (msg->len & 0xff00) >> 8;
|
|
|
|
if ((flags & SERIALI2C_RD) == 0) {
|
|
for (j = 0; j < msg->len; j++)
|
|
buf[pos++] = msg->buf[j];
|
|
}
|
|
}
|
|
|
|
request->xfer.data_size = pos;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* The data in the BPMP -> CPU direction is composed of sequential blocks for
|
|
* those messages that have I2C_M_RD. So, for example, if you have:
|
|
*
|
|
* - !I2C_M_RD, len == 5, data == a0 01 02 03 04
|
|
* - !I2C_M_RD, len == 1, data == a0
|
|
* - I2C_M_RD, len == 2, data == [uninitialized buffer 1]
|
|
* - !I2C_M_RD, len == 1, data == a2
|
|
* - I2C_M_RD, len == 2, data == [uninitialized buffer 2]
|
|
*
|
|
* ...then the data in the BPMP -> CPU direction would be 4 bytes total, and
|
|
* would contain 2 bytes that will go to uninitialized buffer 1, and 2 bytes
|
|
* that will go to uninitialized buffer 2.
|
|
*/
|
|
static int tegra_bpmp_i2c_deserialize(struct tegra_bpmp_i2c *i2c,
|
|
struct mrq_i2c_response *response,
|
|
struct i2c_msg *msgs,
|
|
unsigned int num)
|
|
{
|
|
size_t size = response->xfer.data_size, len = 0, pos = 0;
|
|
char *buf = response->xfer.data_buf;
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < num; i++)
|
|
if (msgs[i].flags & I2C_M_RD)
|
|
len += msgs[i].len;
|
|
|
|
if (len != size)
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < num; i++) {
|
|
if (msgs[i].flags & I2C_M_RD) {
|
|
memcpy(msgs[i].buf, buf + pos, msgs[i].len);
|
|
pos += msgs[i].len;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tegra_bpmp_i2c_msg_len_check(struct i2c_msg *msgs, unsigned int num)
|
|
{
|
|
size_t tx_len = 0, rx_len = 0;
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < num; i++)
|
|
if (!(msgs[i].flags & I2C_M_RD))
|
|
tx_len += SERIALI2C_HDR_SIZE + msgs[i].len;
|
|
|
|
if (tx_len > TEGRA_I2C_IPC_MAX_IN_BUF_SIZE)
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < num; i++)
|
|
if ((msgs[i].flags & I2C_M_RD))
|
|
rx_len += msgs[i].len;
|
|
|
|
if (rx_len > TEGRA_I2C_IPC_MAX_OUT_BUF_SIZE)
|
|
return -EINVAL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int tegra_bpmp_i2c_msg_xfer(struct tegra_bpmp_i2c *i2c,
|
|
struct mrq_i2c_request *request,
|
|
struct mrq_i2c_response *response)
|
|
{
|
|
struct tegra_bpmp_message msg;
|
|
int err;
|
|
|
|
request->cmd = CMD_I2C_XFER;
|
|
request->xfer.bus_id = i2c->bus;
|
|
|
|
memset(&msg, 0, sizeof(msg));
|
|
msg.mrq = MRQ_I2C;
|
|
msg.tx.data = request;
|
|
msg.tx.size = sizeof(*request);
|
|
msg.rx.data = response;
|
|
msg.rx.size = sizeof(*response);
|
|
|
|
if (irqs_disabled())
|
|
err = tegra_bpmp_transfer_atomic(i2c->bpmp, &msg);
|
|
else
|
|
err = tegra_bpmp_transfer(i2c->bpmp, &msg);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int tegra_bpmp_i2c_xfer(struct i2c_adapter *adapter,
|
|
struct i2c_msg *msgs, int num)
|
|
{
|
|
struct tegra_bpmp_i2c *i2c = i2c_get_adapdata(adapter);
|
|
struct mrq_i2c_response response;
|
|
struct mrq_i2c_request request;
|
|
int err;
|
|
|
|
err = tegra_bpmp_i2c_msg_len_check(msgs, num);
|
|
if (err < 0) {
|
|
dev_err(i2c->dev, "unsupported message length\n");
|
|
return err;
|
|
}
|
|
|
|
memset(&request, 0, sizeof(request));
|
|
memset(&response, 0, sizeof(response));
|
|
|
|
err = tegra_bpmp_serialize_i2c_msg(i2c, &request, msgs, num);
|
|
if (err < 0) {
|
|
dev_err(i2c->dev, "failed to serialize message: %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
err = tegra_bpmp_i2c_msg_xfer(i2c, &request, &response);
|
|
if (err < 0) {
|
|
dev_err(i2c->dev, "failed to transfer message: %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
err = tegra_bpmp_i2c_deserialize(i2c, &response, msgs, num);
|
|
if (err < 0) {
|
|
dev_err(i2c->dev, "failed to deserialize message: %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
return num;
|
|
}
|
|
|
|
static u32 tegra_bpmp_i2c_func(struct i2c_adapter *adapter)
|
|
{
|
|
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
|
|
I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_NOSTART;
|
|
}
|
|
|
|
static const struct i2c_algorithm tegra_bpmp_i2c_algo = {
|
|
.master_xfer = tegra_bpmp_i2c_xfer,
|
|
.functionality = tegra_bpmp_i2c_func,
|
|
};
|
|
|
|
static int tegra_bpmp_i2c_probe(struct platform_device *pdev)
|
|
{
|
|
struct tegra_bpmp_i2c *i2c;
|
|
u32 value;
|
|
int err;
|
|
|
|
i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
|
|
if (!i2c)
|
|
return -ENOMEM;
|
|
|
|
i2c->dev = &pdev->dev;
|
|
|
|
i2c->bpmp = dev_get_drvdata(pdev->dev.parent);
|
|
if (!i2c->bpmp)
|
|
return -ENODEV;
|
|
|
|
err = of_property_read_u32(pdev->dev.of_node, "nvidia,bpmp-bus-id",
|
|
&value);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
i2c->bus = value;
|
|
|
|
i2c_set_adapdata(&i2c->adapter, i2c);
|
|
i2c->adapter.owner = THIS_MODULE;
|
|
strlcpy(i2c->adapter.name, "Tegra BPMP I2C adapter",
|
|
sizeof(i2c->adapter.name));
|
|
i2c->adapter.algo = &tegra_bpmp_i2c_algo;
|
|
i2c->adapter.dev.parent = &pdev->dev;
|
|
i2c->adapter.dev.of_node = pdev->dev.of_node;
|
|
|
|
platform_set_drvdata(pdev, i2c);
|
|
|
|
return i2c_add_adapter(&i2c->adapter);
|
|
}
|
|
|
|
static int tegra_bpmp_i2c_remove(struct platform_device *pdev)
|
|
{
|
|
struct tegra_bpmp_i2c *i2c = platform_get_drvdata(pdev);
|
|
|
|
i2c_del_adapter(&i2c->adapter);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id tegra_bpmp_i2c_of_match[] = {
|
|
{ .compatible = "nvidia,tegra186-bpmp-i2c", },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, tegra_bpmp_i2c_of_match);
|
|
|
|
static struct platform_driver tegra_bpmp_i2c_driver = {
|
|
.driver = {
|
|
.name = "tegra-bpmp-i2c",
|
|
.of_match_table = tegra_bpmp_i2c_of_match,
|
|
},
|
|
.probe = tegra_bpmp_i2c_probe,
|
|
.remove = tegra_bpmp_i2c_remove,
|
|
};
|
|
module_platform_driver(tegra_bpmp_i2c_driver);
|
|
|
|
MODULE_DESCRIPTION("NVIDIA Tegra BPMP I2C bus contoller driver");
|
|
MODULE_AUTHOR("Shardar Shariff Md <smohammed@nvidia.com>");
|
|
MODULE_AUTHOR("Juha-Matti Tilli");
|
|
MODULE_LICENSE("GPL v2");
|