// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
* AMD MP2 platform driver
*
* Setup the I2C adapters enumerated in the ACPI namespace.
* MP2 controllers have 2 separate busses, up to 2 I2C adapters may be listed.
*
* Authors: Nehal Bakulchandra Shah <[email protected]>
* Elie Morisse <[email protected]>
*/
#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/types.h>
#include "i2c-amd-mp2.h"
#define AMD_MP2_I2C_MAX_RW_LENGTH ((1 << 12) - 1)
#define AMD_I2C_TIMEOUT (msecs_to_jiffies(250))
/**
* struct amd_i2c_dev - MP2 bus/i2c adapter context
* @common: shared context with the MP2 PCI driver
* @pdev: platform driver node
* @adap: i2c adapter
* @cmd_complete: xfer completion object
*/
struct amd_i2c_dev {
struct amd_i2c_common common;
struct platform_device *pdev;
struct i2c_adapter adap;
struct completion cmd_complete;
};
#define amd_i2c_dev_common(__common) \
container_of(__common, struct amd_i2c_dev, common)
static int i2c_amd_dma_map(struct amd_i2c_common *i2c_common)
{
struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev;
struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
enum dma_data_direction dma_direction =
i2c_common->msg->flags & I2C_M_RD ?
DMA_FROM_DEVICE : DMA_TO_DEVICE;
i2c_common->dma_buf = i2c_get_dma_safe_msg_buf(i2c_common->msg, 0);
i2c_common->dma_addr = dma_map_single(dev_pci, i2c_common->dma_buf,
i2c_common->msg->len,
dma_direction);
if (unlikely(dma_mapping_error(dev_pci, i2c_common->dma_addr))) {
dev_err(&i2c_dev->pdev->dev,
"Error while mapping dma buffer %p\n",
i2c_common->dma_buf);
return -EIO;
}
return 0;
}
static void i2c_amd_dma_unmap(struct amd_i2c_common *i2c_common)
{
struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev;
enum dma_data_direction dma_direction =
i2c_common->msg->flags & I2C_M_RD ?
DMA_FROM_DEVICE : DMA_TO_DEVICE;
dma_unmap_single(dev_pci, i2c_common->dma_addr,
i2c_common->msg->len, dma_direction);
i2c_put_dma_safe_msg_buf(i2c_common->dma_buf, i2c_common->msg, true);
}
static void i2c_amd_start_cmd(struct amd_i2c_dev *i2c_dev)
{
struct amd_i2c_common *i2c_common = &i2c_dev->common;
reinit_completion(&i2c_dev->cmd_complete);
i2c_common->cmd_success = false;
}
static void i2c_amd_cmd_completion(struct amd_i2c_common *i2c_common)
{
struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
union i2c_event *event = &i2c_common->eventval;
if (event->r.status == i2c_readcomplete_event)
dev_dbg(&i2c_dev->pdev->dev, "readdata:%*ph\n", event->r.length,
i2c_common->msg->buf);
complete(&i2c_dev->cmd_complete);
}
static int i2c_amd_check_cmd_completion(struct amd_i2c_dev *i2c_dev)
{
struct amd_i2c_common *i2c_common = &i2c_dev->common;
unsigned long time_left;
time_left = wait_for_completion_timeout(&i2c_dev->cmd_complete,
i2c_dev->adap.timeout);
if ((i2c_common->reqcmd == i2c_read ||
i2c_common->reqcmd == i2c_write) &&
i2c_common->msg->len > 32)
i2c_amd_dma_unmap(i2c_common);
if (time_left == 0) {
amd_mp2_rw_timeout(i2c_common);
return -ETIMEDOUT;
}
amd_mp2_process_event(i2c_common);
if (!i2c_common->cmd_success)
return -EIO;
return 0;
}
static int i2c_amd_enable_set(struct amd_i2c_dev *i2c_dev, bool enable)
{
struct amd_i2c_common *i2c_common = &i2c_dev->common;
i2c_amd_start_cmd(i2c_dev);
amd_mp2_bus_enable_set(i2c_common, enable);
return i2c_amd_check_cmd_completion(i2c_dev);
}
static int i2c_amd_xfer_msg(struct amd_i2c_dev *i2c_dev, struct i2c_msg *pmsg)
{
struct amd_i2c_common *i2c_common = &i2c_dev->common;
i2c_amd_start_cmd(i2c_dev);
i2c_common->msg = pmsg;
if (pmsg->len > 32)
if (i2c_amd_dma_map(i2c_common))
return -EIO;
if (pmsg->flags & I2C_M_RD)
amd_mp2_rw(i2c_common, i2c_read);
else
amd_mp2_rw(i2c_common, i2c_write);
return i2c_amd_check_cmd_completion(i2c_dev);
}
static int i2c_amd_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
struct amd_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
int i;
struct i2c_msg *pmsg;
int err = 0;
/* the adapter might have been deleted while waiting for the bus lock */
if (unlikely(!i2c_dev->common.mp2_dev))
return -EINVAL;
amd_mp2_pm_runtime_get(i2c_dev->common.mp2_dev);
for (i = 0; i < num; i++) {
pmsg = &msgs[i];
err = i2c_amd_xfer_msg(i2c_dev, pmsg);
if (err)
break;
}
amd_mp2_pm_runtime_put(i2c_dev->common.mp2_dev);
return err ? err : num;
}
static u32 i2c_amd_func(struct i2c_adapter *a)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static const struct i2c_algorithm i2c_amd_algorithm = {
.master_xfer = i2c_amd_xfer,
.functionality = i2c_amd_func,
};
#ifdef CONFIG_PM
static int i2c_amd_suspend(struct amd_i2c_common *i2c_common)
{
struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
i2c_amd_enable_set(i2c_dev, false);
return 0;
}
static int i2c_amd_resume(struct amd_i2c_common *i2c_common)
{
struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
return i2c_amd_enable_set(i2c_dev, true);
}
#endif
static const u32 supported_speeds[] = {
I2C_MAX_HIGH_SPEED_MODE_FREQ,
I2C_MAX_TURBO_MODE_FREQ,
I2C_MAX_FAST_MODE_PLUS_FREQ,
I2C_MAX_FAST_MODE_FREQ,
I2C_MAX_STANDARD_MODE_FREQ,
};
static enum speed_enum i2c_amd_get_bus_speed(struct platform_device *pdev)
{
u32 acpi_speed;
int i;
acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
/* round down to the lowest standard speed */
for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) {
if (acpi_speed >= supported_speeds[i])
break;
}
acpi_speed = i < ARRAY_SIZE(supported_speeds) ? supported_speeds[i] : 0;
switch (acpi_speed) {
case I2C_MAX_STANDARD_MODE_FREQ:
return speed100k;
case I2C_MAX_FAST_MODE_FREQ:
return speed400k;
case I2C_MAX_FAST_MODE_PLUS_FREQ:
return speed1000k;
case I2C_MAX_TURBO_MODE_FREQ:
return speed1400k;
case I2C_MAX_HIGH_SPEED_MODE_FREQ:
return speed3400k;
default:
return speed400k;
}
}
static const struct i2c_adapter_quirks amd_i2c_dev_quirks = {
.max_read_len = AMD_MP2_I2C_MAX_RW_LENGTH,
.max_write_len = AMD_MP2_I2C_MAX_RW_LENGTH,
};
static int i2c_amd_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
int ret;
struct amd_i2c_dev *i2c_dev;
struct amd_mp2_dev *mp2_dev;
u64 uid;
ret = acpi_dev_uid_to_integer(ACPI_COMPANION(dev), &uid);
if (ret)
return dev_err_probe(dev, ret, "missing UID/bus id!\n");
if (uid >= 2)
return dev_err_probe(dev, -EINVAL, "incorrect UID/bus id \"%llu\"!\n", uid);
dev_dbg(dev, "bus id is %llu\n", uid);
/* The ACPI namespace doesn't contain information about which MP2 PCI
* device an AMDI0011 ACPI device is related to, so assume that there's
* only one MP2 PCI device per system.
*/
mp2_dev = amd_mp2_find_device();
if (!mp2_dev || !mp2_dev->probed)
/* The MP2 PCI device should get probed later */
return -EPROBE_DEFER;
i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
if (!i2c_dev)
return -ENOMEM;
i2c_dev->common.bus_id = uid;
i2c_dev->common.mp2_dev = mp2_dev;
i2c_dev->pdev = pdev;
platform_set_drvdata(pdev, i2c_dev);
i2c_dev->common.cmd_completion = &i2c_amd_cmd_completion;
#ifdef CONFIG_PM
i2c_dev->common.suspend = &i2c_amd_suspend;
i2c_dev->common.resume = &i2c_amd_resume;
#endif
/* Register the adapter */
amd_mp2_pm_runtime_get(mp2_dev);
i2c_dev->common.reqcmd = i2c_none;
if (amd_mp2_register_cb(&i2c_dev->common))
return -EINVAL;
device_link_add(&i2c_dev->pdev->dev, &mp2_dev->pci_dev->dev,
DL_FLAG_AUTOREMOVE_CONSUMER);
i2c_dev->common.i2c_speed = i2c_amd_get_bus_speed(pdev);
/* Setup i2c adapter description */
i2c_dev->adap.owner = THIS_MODULE;
i2c_dev->adap.algo = &i2c_amd_algorithm;
i2c_dev->adap.quirks = &amd_i2c_dev_quirks;
i2c_dev->adap.dev.parent = &pdev->dev;
i2c_dev->adap.algo_data = i2c_dev;
i2c_dev->adap.timeout = AMD_I2C_TIMEOUT;
ACPI_COMPANION_SET(&i2c_dev->adap.dev, ACPI_COMPANION(&pdev->dev));
i2c_dev->adap.dev.of_node = pdev->dev.of_node;
snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name),
"AMD MP2 i2c bus %u", i2c_dev->common.bus_id);
i2c_set_adapdata(&i2c_dev->adap, i2c_dev);
init_completion(&i2c_dev->cmd_complete);
/* Enable the bus */
if (i2c_amd_enable_set(i2c_dev, true))
dev_err(&pdev->dev, "initial bus enable failed\n");
/* Attach to the i2c layer */
ret = i2c_add_adapter(&i2c_dev->adap);
amd_mp2_pm_runtime_put(mp2_dev);
if (ret < 0)
dev_err(&pdev->dev, "i2c add adapter failed = %d\n", ret);
return ret;
}
static void i2c_amd_remove(struct platform_device *pdev)
{
struct amd_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
struct amd_i2c_common *i2c_common = &i2c_dev->common;
i2c_lock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
i2c_amd_enable_set(i2c_dev, false);
amd_mp2_unregister_cb(i2c_common);
i2c_common->mp2_dev = NULL;
i2c_unlock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
i2c_del_adapter(&i2c_dev->adap);
}
static const struct acpi_device_id i2c_amd_acpi_match[] = {
{ "AMDI0011" },
{ }
};
MODULE_DEVICE_TABLE(acpi, i2c_amd_acpi_match);
static struct platform_driver i2c_amd_plat_driver = {
.probe = i2c_amd_probe,
.remove_new = i2c_amd_remove,
.driver = {
.name = "i2c_amd_mp2",
.acpi_match_table = ACPI_PTR(i2c_amd_acpi_match),
},
};
module_platform_driver(i2c_amd_plat_driver);
MODULE_DESCRIPTION("AMD(R) MP2 I2C Platform Driver");
MODULE_AUTHOR("Nehal Shah <[email protected]>");
MODULE_AUTHOR("Elie Morisse <[email protected]>");
MODULE_LICENSE("Dual BSD/GPL");
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