linux/drivers/input/rmi4/rmi_smbus.c
Dmitry Torokhov 5030b2fe6a Input: synaptics-rmi4 - handle reset delay when using SMBus trsnsport
Touch controllers need some time after receiving reset command for the
firmware to finish re-initializing and be ready to respond to commands
from the host. The driver already had handling for the post-reset delay
for I2C and SPI transports, this change adds the handling to
SMBus-connected devices.

SMBus devices are peculiar because they implement legacy PS/2
compatibility mode, so reset is actually issued by psmouse driver on the
associated serio port, after which the control is passed to the RMI4
driver with SMBus companion device.

Note that originally the delay was added to psmouse driver in
92e24e0e57 ("Input: psmouse - add delay when deactivating for SMBus
mode"), but that resulted in an unwanted delay in "fast" reconnect
handler for the serio port, so it was decided to revert the patch and
have the delay being handled in the RMI4 driver, similar to the other
transports.

Tested-by: Jeffery Miller <jefferymiller@google.com>
Link: https://lore.kernel.org/r/ZR1yUFJ8a9Zt606N@penguin
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2023-10-13 17:59:19 -07:00

437 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2015 - 2016 Red Hat, Inc
* Copyright (c) 2011, 2012 Synaptics Incorporated
* Copyright (c) 2011 Unixphere
*/
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/kconfig.h>
#include <linux/lockdep.h>
#include <linux/module.h>
#include <linux/pm.h>
#include <linux/rmi.h>
#include <linux/slab.h>
#include "rmi_driver.h"
#define SMB_PROTOCOL_VERSION_ADDRESS 0xfd
#define SMB_MAX_COUNT 32
#define RMI_SMB2_MAP_SIZE 8 /* 8 entry of 4 bytes each */
#define RMI_SMB2_MAP_FLAGS_WE 0x01
struct mapping_table_entry {
__le16 rmiaddr;
u8 readcount;
u8 flags;
};
struct rmi_smb_xport {
struct rmi_transport_dev xport;
struct i2c_client *client;
struct mutex page_mutex;
int page;
u8 table_index;
struct mutex mappingtable_mutex;
struct mapping_table_entry mapping_table[RMI_SMB2_MAP_SIZE];
};
static int rmi_smb_get_version(struct rmi_smb_xport *rmi_smb)
{
struct i2c_client *client = rmi_smb->client;
int retval;
/* Check if for SMBus new version device by reading version byte. */
retval = i2c_smbus_read_byte_data(client, SMB_PROTOCOL_VERSION_ADDRESS);
if (retval < 0) {
dev_err(&client->dev, "failed to get SMBus version number!\n");
return retval;
}
return retval + 1;
}
/* SMB block write - wrapper over ic2_smb_write_block */
static int smb_block_write(struct rmi_transport_dev *xport,
u8 commandcode, const void *buf, size_t len)
{
struct rmi_smb_xport *rmi_smb =
container_of(xport, struct rmi_smb_xport, xport);
struct i2c_client *client = rmi_smb->client;
int retval;
retval = i2c_smbus_write_block_data(client, commandcode, len, buf);
rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
"wrote %zd bytes at %#04x: %d (%*ph)\n",
len, commandcode, retval, (int)len, buf);
return retval;
}
/*
* The function to get command code for smbus operations and keeps
* records to the driver mapping table
*/
static int rmi_smb_get_command_code(struct rmi_transport_dev *xport,
u16 rmiaddr, int bytecount, bool isread, u8 *commandcode)
{
struct rmi_smb_xport *rmi_smb =
container_of(xport, struct rmi_smb_xport, xport);
struct mapping_table_entry new_map;
int i;
int retval = 0;
mutex_lock(&rmi_smb->mappingtable_mutex);
for (i = 0; i < RMI_SMB2_MAP_SIZE; i++) {
struct mapping_table_entry *entry = &rmi_smb->mapping_table[i];
if (le16_to_cpu(entry->rmiaddr) == rmiaddr) {
if (isread) {
if (entry->readcount == bytecount)
goto exit;
} else {
if (entry->flags & RMI_SMB2_MAP_FLAGS_WE) {
goto exit;
}
}
}
}
i = rmi_smb->table_index;
rmi_smb->table_index = (i + 1) % RMI_SMB2_MAP_SIZE;
/* constructs mapping table data entry. 4 bytes each entry */
memset(&new_map, 0, sizeof(new_map));
new_map.rmiaddr = cpu_to_le16(rmiaddr);
new_map.readcount = bytecount;
new_map.flags = !isread ? RMI_SMB2_MAP_FLAGS_WE : 0;
retval = smb_block_write(xport, i + 0x80, &new_map, sizeof(new_map));
if (retval < 0) {
/*
* if not written to device mapping table
* clear the driver mapping table records
*/
memset(&new_map, 0, sizeof(new_map));
}
/* save to the driver level mapping table */
rmi_smb->mapping_table[i] = new_map;
exit:
mutex_unlock(&rmi_smb->mappingtable_mutex);
if (retval < 0)
return retval;
*commandcode = i;
return 0;
}
static int rmi_smb_write_block(struct rmi_transport_dev *xport, u16 rmiaddr,
const void *databuff, size_t len)
{
int retval = 0;
u8 commandcode;
struct rmi_smb_xport *rmi_smb =
container_of(xport, struct rmi_smb_xport, xport);
int cur_len = (int)len;
mutex_lock(&rmi_smb->page_mutex);
while (cur_len > 0) {
/*
* break into 32 bytes chunks to write get command code
*/
int block_len = min_t(int, len, SMB_MAX_COUNT);
retval = rmi_smb_get_command_code(xport, rmiaddr, block_len,
false, &commandcode);
if (retval < 0)
goto exit;
retval = smb_block_write(xport, commandcode,
databuff, block_len);
if (retval < 0)
goto exit;
/* prepare to write next block of bytes */
cur_len -= SMB_MAX_COUNT;
databuff += SMB_MAX_COUNT;
rmiaddr += SMB_MAX_COUNT;
}
exit:
mutex_unlock(&rmi_smb->page_mutex);
return retval;
}
/* SMB block read - wrapper over ic2_smb_read_block */
static int smb_block_read(struct rmi_transport_dev *xport,
u8 commandcode, void *buf, size_t len)
{
struct rmi_smb_xport *rmi_smb =
container_of(xport, struct rmi_smb_xport, xport);
struct i2c_client *client = rmi_smb->client;
int retval;
retval = i2c_smbus_read_block_data(client, commandcode, buf);
if (retval < 0)
return retval;
return retval;
}
static int rmi_smb_read_block(struct rmi_transport_dev *xport, u16 rmiaddr,
void *databuff, size_t len)
{
struct rmi_smb_xport *rmi_smb =
container_of(xport, struct rmi_smb_xport, xport);
int retval;
u8 commandcode;
int cur_len = (int)len;
mutex_lock(&rmi_smb->page_mutex);
memset(databuff, 0, len);
while (cur_len > 0) {
/* break into 32 bytes chunks to write get command code */
int block_len = min_t(int, cur_len, SMB_MAX_COUNT);
retval = rmi_smb_get_command_code(xport, rmiaddr, block_len,
true, &commandcode);
if (retval < 0)
goto exit;
retval = smb_block_read(xport, commandcode,
databuff, block_len);
if (retval < 0)
goto exit;
/* prepare to read next block of bytes */
cur_len -= SMB_MAX_COUNT;
databuff += SMB_MAX_COUNT;
rmiaddr += SMB_MAX_COUNT;
}
retval = 0;
exit:
mutex_unlock(&rmi_smb->page_mutex);
return retval;
}
static void rmi_smb_clear_state(struct rmi_smb_xport *rmi_smb)
{
/* the mapping table has been flushed, discard the current one */
mutex_lock(&rmi_smb->mappingtable_mutex);
memset(rmi_smb->mapping_table, 0, sizeof(rmi_smb->mapping_table));
mutex_unlock(&rmi_smb->mappingtable_mutex);
}
static int rmi_smb_enable_smbus_mode(struct rmi_smb_xport *rmi_smb)
{
struct i2c_client *client = rmi_smb->client;
int smbus_version;
/*
* psmouse driver resets the controller, we only need to wait
* to give the firmware chance to fully reinitialize.
*/
if (rmi_smb->xport.pdata.reset_delay_ms)
msleep(rmi_smb->xport.pdata.reset_delay_ms);
/* we need to get the smbus version to activate the touchpad */
smbus_version = rmi_smb_get_version(rmi_smb);
if (smbus_version < 0)
return smbus_version;
rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Smbus version is %d",
smbus_version);
if (smbus_version != 2 && smbus_version != 3) {
dev_err(&client->dev, "Unrecognized SMB version %d\n",
smbus_version);
return -ENODEV;
}
return 0;
}
static int rmi_smb_reset(struct rmi_transport_dev *xport, u16 reset_addr)
{
struct rmi_smb_xport *rmi_smb =
container_of(xport, struct rmi_smb_xport, xport);
rmi_smb_clear_state(rmi_smb);
/*
* We do not call the actual reset command, it has to be handled in
* PS/2 or there will be races between PS/2 and SMBus. PS/2 should
* ensure that a psmouse_reset is called before initializing the
* device and after it has been removed to be in a known state.
*/
return rmi_smb_enable_smbus_mode(rmi_smb);
}
static const struct rmi_transport_ops rmi_smb_ops = {
.write_block = rmi_smb_write_block,
.read_block = rmi_smb_read_block,
.reset = rmi_smb_reset,
};
static int rmi_smb_probe(struct i2c_client *client)
{
struct rmi_device_platform_data *pdata = dev_get_platdata(&client->dev);
struct rmi_smb_xport *rmi_smb;
int error;
if (!pdata) {
dev_err(&client->dev, "no platform data, aborting\n");
return -ENOMEM;
}
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_READ_BLOCK_DATA |
I2C_FUNC_SMBUS_HOST_NOTIFY)) {
dev_err(&client->dev,
"adapter does not support required functionality\n");
return -ENODEV;
}
if (client->irq <= 0) {
dev_err(&client->dev, "no IRQ provided, giving up\n");
return client->irq ? client->irq : -ENODEV;
}
rmi_smb = devm_kzalloc(&client->dev, sizeof(struct rmi_smb_xport),
GFP_KERNEL);
if (!rmi_smb)
return -ENOMEM;
rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s\n",
dev_name(&client->dev));
rmi_smb->client = client;
mutex_init(&rmi_smb->page_mutex);
mutex_init(&rmi_smb->mappingtable_mutex);
rmi_smb->xport.dev = &client->dev;
rmi_smb->xport.pdata = *pdata;
rmi_smb->xport.pdata.irq = client->irq;
rmi_smb->xport.proto_name = "smb";
rmi_smb->xport.ops = &rmi_smb_ops;
error = rmi_smb_enable_smbus_mode(rmi_smb);
if (error)
return error;
i2c_set_clientdata(client, rmi_smb);
dev_info(&client->dev, "registering SMbus-connected sensor\n");
error = rmi_register_transport_device(&rmi_smb->xport);
if (error) {
dev_err(&client->dev, "failed to register sensor: %d\n", error);
return error;
}
return 0;
}
static void rmi_smb_remove(struct i2c_client *client)
{
struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
rmi_unregister_transport_device(&rmi_smb->xport);
}
static int rmi_smb_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
int ret;
ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev, true);
if (ret)
dev_warn(dev, "Failed to suspend device: %d\n", ret);
return ret;
}
static int rmi_smb_runtime_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
int ret;
ret = rmi_driver_suspend(rmi_smb->xport.rmi_dev, false);
if (ret)
dev_warn(dev, "Failed to suspend device: %d\n", ret);
return ret;
}
static int rmi_smb_resume(struct device *dev)
{
struct i2c_client *client = container_of(dev, struct i2c_client, dev);
struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
struct rmi_device *rmi_dev = rmi_smb->xport.rmi_dev;
int ret;
rmi_smb_reset(&rmi_smb->xport, 0);
rmi_reset(rmi_dev);
ret = rmi_driver_resume(rmi_smb->xport.rmi_dev, true);
if (ret)
dev_warn(dev, "Failed to resume device: %d\n", ret);
return 0;
}
static int rmi_smb_runtime_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct rmi_smb_xport *rmi_smb = i2c_get_clientdata(client);
int ret;
ret = rmi_driver_resume(rmi_smb->xport.rmi_dev, false);
if (ret)
dev_warn(dev, "Failed to resume device: %d\n", ret);
return 0;
}
static const struct dev_pm_ops rmi_smb_pm = {
SYSTEM_SLEEP_PM_OPS(rmi_smb_suspend, rmi_smb_resume)
RUNTIME_PM_OPS(rmi_smb_runtime_suspend, rmi_smb_runtime_resume, NULL)
};
static const struct i2c_device_id rmi_id[] = {
{ "rmi4_smbus", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, rmi_id);
static struct i2c_driver rmi_smb_driver = {
.driver = {
.name = "rmi4_smbus",
.pm = pm_ptr(&rmi_smb_pm),
},
.id_table = rmi_id,
.probe = rmi_smb_probe,
.remove = rmi_smb_remove,
};
module_i2c_driver(rmi_smb_driver);
MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>");
MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>");
MODULE_DESCRIPTION("RMI4 SMBus driver");
MODULE_LICENSE("GPL");