https://github.com/torvalds/linux
Tip revision: 0d02ec6b3136c73c09e7859f0d0e4e2c4c07b49b authored by Linus Torvalds on 21 March 2021, 21:56:43 UTC
Linux 5.12-rc4
Linux 5.12-rc4
Tip revision: 0d02ec6
i2c-amd-mp2-pci.c
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
* AMD MP2 PCIe communication driver
*
* Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
* Elie Morisse <syniurge@gmail.com>
*/
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include "i2c-amd-mp2.h"
#include <linux/io-64-nonatomic-lo-hi.h>
static void amd_mp2_c2p_mutex_lock(struct amd_i2c_common *i2c_common)
{
struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
/* there is only one data mailbox for two i2c adapters */
mutex_lock(&privdata->c2p_lock);
privdata->c2p_lock_busid = i2c_common->bus_id;
}
static void amd_mp2_c2p_mutex_unlock(struct amd_i2c_common *i2c_common)
{
struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
if (unlikely(privdata->c2p_lock_busid != i2c_common->bus_id)) {
pci_warn(privdata->pci_dev,
"bus %d attempting to unlock C2P locked by bus %d\n",
i2c_common->bus_id, privdata->c2p_lock_busid);
return;
}
mutex_unlock(&privdata->c2p_lock);
}
static int amd_mp2_cmd(struct amd_i2c_common *i2c_common,
union i2c_cmd_base i2c_cmd_base)
{
struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
void __iomem *reg;
i2c_common->reqcmd = i2c_cmd_base.s.i2c_cmd;
reg = privdata->mmio + ((i2c_cmd_base.s.bus_id == 1) ?
AMD_C2P_MSG1 : AMD_C2P_MSG0);
writel(i2c_cmd_base.ul, reg);
return 0;
}
int amd_mp2_bus_enable_set(struct amd_i2c_common *i2c_common, bool enable)
{
struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
union i2c_cmd_base i2c_cmd_base;
pci_dbg(privdata->pci_dev, "id: %d\n", i2c_common->bus_id);
i2c_cmd_base.ul = 0;
i2c_cmd_base.s.i2c_cmd = enable ? i2c_enable : i2c_disable;
i2c_cmd_base.s.bus_id = i2c_common->bus_id;
i2c_cmd_base.s.i2c_speed = i2c_common->i2c_speed;
amd_mp2_c2p_mutex_lock(i2c_common);
return amd_mp2_cmd(i2c_common, i2c_cmd_base);
}
EXPORT_SYMBOL_GPL(amd_mp2_bus_enable_set);
static void amd_mp2_cmd_rw_fill(struct amd_i2c_common *i2c_common,
union i2c_cmd_base *i2c_cmd_base,
enum i2c_cmd reqcmd)
{
i2c_cmd_base->s.i2c_cmd = reqcmd;
i2c_cmd_base->s.bus_id = i2c_common->bus_id;
i2c_cmd_base->s.i2c_speed = i2c_common->i2c_speed;
i2c_cmd_base->s.slave_addr = i2c_common->msg->addr;
i2c_cmd_base->s.length = i2c_common->msg->len;
}
int amd_mp2_rw(struct amd_i2c_common *i2c_common, enum i2c_cmd reqcmd)
{
struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
union i2c_cmd_base i2c_cmd_base;
amd_mp2_cmd_rw_fill(i2c_common, &i2c_cmd_base, reqcmd);
amd_mp2_c2p_mutex_lock(i2c_common);
if (i2c_common->msg->len <= 32) {
i2c_cmd_base.s.mem_type = use_c2pmsg;
if (reqcmd == i2c_write)
memcpy_toio(privdata->mmio + AMD_C2P_MSG2,
i2c_common->msg->buf,
i2c_common->msg->len);
} else {
i2c_cmd_base.s.mem_type = use_dram;
writeq((u64)i2c_common->dma_addr,
privdata->mmio + AMD_C2P_MSG2);
}
return amd_mp2_cmd(i2c_common, i2c_cmd_base);
}
EXPORT_SYMBOL_GPL(amd_mp2_rw);
static void amd_mp2_pci_check_rw_event(struct amd_i2c_common *i2c_common)
{
struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
struct pci_dev *pdev = privdata->pci_dev;
int len = i2c_common->eventval.r.length;
u32 slave_addr = i2c_common->eventval.r.slave_addr;
bool err = false;
if (unlikely(len != i2c_common->msg->len)) {
pci_err(pdev, "length %d in event doesn't match buffer length %d!\n",
len, i2c_common->msg->len);
err = true;
}
if (unlikely(slave_addr != i2c_common->msg->addr)) {
pci_err(pdev, "unexpected slave address %x (expected: %x)!\n",
slave_addr, i2c_common->msg->addr);
err = true;
}
if (!err)
i2c_common->cmd_success = true;
}
static void __amd_mp2_process_event(struct amd_i2c_common *i2c_common)
{
struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
struct pci_dev *pdev = privdata->pci_dev;
enum status_type sts = i2c_common->eventval.r.status;
enum response_type res = i2c_common->eventval.r.response;
int len = i2c_common->eventval.r.length;
if (res != command_success) {
if (res != command_failed)
pci_err(pdev, "invalid response to i2c command!\n");
return;
}
switch (i2c_common->reqcmd) {
case i2c_read:
if (sts == i2c_readcomplete_event) {
amd_mp2_pci_check_rw_event(i2c_common);
if (len <= 32)
memcpy_fromio(i2c_common->msg->buf,
privdata->mmio + AMD_C2P_MSG2,
len);
} else if (sts != i2c_readfail_event) {
pci_err(pdev, "invalid i2c status after read (%d)!\n", sts);
}
break;
case i2c_write:
if (sts == i2c_writecomplete_event)
amd_mp2_pci_check_rw_event(i2c_common);
else if (sts != i2c_writefail_event)
pci_err(pdev, "invalid i2c status after write (%d)!\n", sts);
break;
case i2c_enable:
if (sts == i2c_busenable_complete)
i2c_common->cmd_success = true;
else if (sts != i2c_busenable_failed)
pci_err(pdev, "invalid i2c status after bus enable (%d)!\n", sts);
break;
case i2c_disable:
if (sts == i2c_busdisable_complete)
i2c_common->cmd_success = true;
else if (sts != i2c_busdisable_failed)
pci_err(pdev, "invalid i2c status after bus disable (%d)!\n", sts);
break;
default:
break;
}
}
void amd_mp2_process_event(struct amd_i2c_common *i2c_common)
{
struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
struct pci_dev *pdev = privdata->pci_dev;
if (unlikely(i2c_common->reqcmd == i2c_none)) {
pci_warn(pdev, "received msg but no cmd was sent (bus = %d)!\n",
i2c_common->bus_id);
return;
}
__amd_mp2_process_event(i2c_common);
i2c_common->reqcmd = i2c_none;
amd_mp2_c2p_mutex_unlock(i2c_common);
}
EXPORT_SYMBOL_GPL(amd_mp2_process_event);
static irqreturn_t amd_mp2_irq_isr(int irq, void *dev)
{
struct amd_mp2_dev *privdata = dev;
struct pci_dev *pdev = privdata->pci_dev;
struct amd_i2c_common *i2c_common;
u32 val;
unsigned int bus_id;
void __iomem *reg;
enum irqreturn ret = IRQ_NONE;
for (bus_id = 0; bus_id < 2; bus_id++) {
i2c_common = privdata->busses[bus_id];
if (!i2c_common)
continue;
reg = privdata->mmio + ((bus_id == 0) ?
AMD_P2C_MSG1 : AMD_P2C_MSG2);
val = readl(reg);
if (val != 0) {
writel(0, reg);
writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
i2c_common->eventval.ul = val;
i2c_common->cmd_completion(i2c_common);
ret = IRQ_HANDLED;
}
}
if (ret != IRQ_HANDLED) {
val = readl(privdata->mmio + AMD_P2C_MSG_INTEN);
if (val != 0) {
writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
pci_warn(pdev, "received irq without message\n");
ret = IRQ_HANDLED;
}
}
return ret;
}
void amd_mp2_rw_timeout(struct amd_i2c_common *i2c_common)
{
i2c_common->reqcmd = i2c_none;
amd_mp2_c2p_mutex_unlock(i2c_common);
}
EXPORT_SYMBOL_GPL(amd_mp2_rw_timeout);
int amd_mp2_register_cb(struct amd_i2c_common *i2c_common)
{
struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
struct pci_dev *pdev = privdata->pci_dev;
if (i2c_common->bus_id > 1)
return -EINVAL;
if (privdata->busses[i2c_common->bus_id]) {
pci_err(pdev, "Bus %d already taken!\n", i2c_common->bus_id);
return -EINVAL;
}
privdata->busses[i2c_common->bus_id] = i2c_common;
return 0;
}
EXPORT_SYMBOL_GPL(amd_mp2_register_cb);
int amd_mp2_unregister_cb(struct amd_i2c_common *i2c_common)
{
struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
privdata->busses[i2c_common->bus_id] = NULL;
return 0;
}
EXPORT_SYMBOL_GPL(amd_mp2_unregister_cb);
static void amd_mp2_clear_reg(struct amd_mp2_dev *privdata)
{
int reg;
for (reg = AMD_C2P_MSG0; reg <= AMD_C2P_MSG9; reg += 4)
writel(0, privdata->mmio + reg);
for (reg = AMD_P2C_MSG1; reg <= AMD_P2C_MSG2; reg += 4)
writel(0, privdata->mmio + reg);
}
static int amd_mp2_pci_init(struct amd_mp2_dev *privdata,
struct pci_dev *pci_dev)
{
int rc;
pci_set_drvdata(pci_dev, privdata);
rc = pcim_enable_device(pci_dev);
if (rc) {
pci_err(pci_dev, "Failed to enable MP2 PCI device\n");
goto err_pci_enable;
}
rc = pcim_iomap_regions(pci_dev, 1 << 2, pci_name(pci_dev));
if (rc) {
pci_err(pci_dev, "I/O memory remapping failed\n");
goto err_pci_enable;
}
privdata->mmio = pcim_iomap_table(pci_dev)[2];
pci_set_master(pci_dev);
rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(64));
if (rc) {
rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(32));
if (rc)
goto err_dma_mask;
}
/* Set up intx irq */
writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
pci_intx(pci_dev, 1);
rc = devm_request_irq(&pci_dev->dev, pci_dev->irq, amd_mp2_irq_isr,
IRQF_SHARED, dev_name(&pci_dev->dev), privdata);
if (rc)
pci_err(pci_dev, "Failure requesting irq %i: %d\n",
pci_dev->irq, rc);
return rc;
err_dma_mask:
pci_clear_master(pci_dev);
err_pci_enable:
pci_set_drvdata(pci_dev, NULL);
return rc;
}
static int amd_mp2_pci_probe(struct pci_dev *pci_dev,
const struct pci_device_id *id)
{
struct amd_mp2_dev *privdata;
int rc;
privdata = devm_kzalloc(&pci_dev->dev, sizeof(*privdata), GFP_KERNEL);
if (!privdata)
return -ENOMEM;
privdata->pci_dev = pci_dev;
rc = amd_mp2_pci_init(privdata, pci_dev);
if (rc)
return rc;
mutex_init(&privdata->c2p_lock);
pm_runtime_set_autosuspend_delay(&pci_dev->dev, 1000);
pm_runtime_use_autosuspend(&pci_dev->dev);
pm_runtime_put_autosuspend(&pci_dev->dev);
pm_runtime_allow(&pci_dev->dev);
privdata->probed = true;
pci_info(pci_dev, "MP2 device registered.\n");
return 0;
}
static void amd_mp2_pci_remove(struct pci_dev *pci_dev)
{
struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);
pm_runtime_forbid(&pci_dev->dev);
pm_runtime_get_noresume(&pci_dev->dev);
pci_intx(pci_dev, 0);
pci_clear_master(pci_dev);
amd_mp2_clear_reg(privdata);
}
#ifdef CONFIG_PM
static int amd_mp2_pci_suspend(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);
struct amd_i2c_common *i2c_common;
unsigned int bus_id;
int ret = 0;
for (bus_id = 0; bus_id < 2; bus_id++) {
i2c_common = privdata->busses[bus_id];
if (i2c_common)
i2c_common->suspend(i2c_common);
}
ret = pci_save_state(pci_dev);
if (ret) {
pci_err(pci_dev, "pci_save_state failed = %d\n", ret);
return ret;
}
pci_disable_device(pci_dev);
return ret;
}
static int amd_mp2_pci_resume(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);
struct amd_i2c_common *i2c_common;
unsigned int bus_id;
int ret = 0;
pci_restore_state(pci_dev);
ret = pci_enable_device(pci_dev);
if (ret < 0) {
pci_err(pci_dev, "pci_enable_device failed = %d\n", ret);
return ret;
}
for (bus_id = 0; bus_id < 2; bus_id++) {
i2c_common = privdata->busses[bus_id];
if (i2c_common) {
ret = i2c_common->resume(i2c_common);
if (ret < 0)
return ret;
}
}
return ret;
}
static UNIVERSAL_DEV_PM_OPS(amd_mp2_pci_pm_ops, amd_mp2_pci_suspend,
amd_mp2_pci_resume, NULL);
#endif /* CONFIG_PM */
static const struct pci_device_id amd_mp2_pci_tbl[] = {
{PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_MP2)},
{0}
};
MODULE_DEVICE_TABLE(pci, amd_mp2_pci_tbl);
static struct pci_driver amd_mp2_pci_driver = {
.name = "i2c_amd_mp2",
.id_table = amd_mp2_pci_tbl,
.probe = amd_mp2_pci_probe,
.remove = amd_mp2_pci_remove,
#ifdef CONFIG_PM
.driver = {
.pm = &amd_mp2_pci_pm_ops,
},
#endif
};
module_pci_driver(amd_mp2_pci_driver);
struct amd_mp2_dev *amd_mp2_find_device(void)
{
struct device *dev;
struct pci_dev *pci_dev;
dev = driver_find_next_device(&amd_mp2_pci_driver.driver, NULL);
if (!dev)
return NULL;
pci_dev = to_pci_dev(dev);
return (struct amd_mp2_dev *)pci_get_drvdata(pci_dev);
}
EXPORT_SYMBOL_GPL(amd_mp2_find_device);
MODULE_DESCRIPTION("AMD(R) PCI-E MP2 I2C Controller Driver");
MODULE_AUTHOR("Shyam Sundar S K <Shyam-sundar.S-k@amd.com>");
MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>");
MODULE_LICENSE("Dual BSD/GPL");