swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 7ce7d89f48834cefece7804d38fc5d85382edf77 authored by Linus Torvalds on 26 December 2016, 00:13:08 UTC
Linux 4.10-rc1
Linux 4.10-rc1
Tip revision: 7ce7d89
rmi_i2c.c
/*
* Copyright (c) 2011-2016 Synaptics Incorporated
* Copyright (c) 2011 Unixphere
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#include <linux/i2c.h>
#include <linux/rmi.h>
#include <linux/of.h>
#include <linux/delay.h>
#include <linux/regulator/consumer.h>
#include "rmi_driver.h"
#define BUFFER_SIZE_INCREMENT 32
/**
* struct rmi_i2c_xport - stores information for i2c communication
*
* @xport: The transport interface structure
*
* @page_mutex: Locks current page to avoid changing pages in unexpected ways.
* @page: Keeps track of the current virtual page
*
* @tx_buf: Buffer used for transmitting data to the sensor over i2c.
* @tx_buf_size: Size of the buffer
*/
struct rmi_i2c_xport {
struct rmi_transport_dev xport;
struct i2c_client *client;
struct mutex page_mutex;
int page;
u8 *tx_buf;
size_t tx_buf_size;
struct regulator_bulk_data supplies[2];
u32 startup_delay;
};
#define RMI_PAGE_SELECT_REGISTER 0xff
#define RMI_I2C_PAGE(addr) (((addr) >> 8) & 0xff)
/*
* rmi_set_page - Set RMI page
* @xport: The pointer to the rmi_transport_dev struct
* @page: The new page address.
*
* RMI devices have 16-bit addressing, but some of the transport
* implementations (like SMBus) only have 8-bit addressing. So RMI implements
* a page address at 0xff of every page so we can reliable page addresses
* every 256 registers.
*
* The page_mutex lock must be held when this function is entered.
*
* Returns zero on success, non-zero on failure.
*/
static int rmi_set_page(struct rmi_i2c_xport *rmi_i2c, u8 page)
{
struct i2c_client *client = rmi_i2c->client;
u8 txbuf[2] = {RMI_PAGE_SELECT_REGISTER, page};
int retval;
retval = i2c_master_send(client, txbuf, sizeof(txbuf));
if (retval != sizeof(txbuf)) {
dev_err(&client->dev,
"%s: set page failed: %d.", __func__, retval);
return (retval < 0) ? retval : -EIO;
}
rmi_i2c->page = page;
return 0;
}
static int rmi_i2c_write_block(struct rmi_transport_dev *xport, u16 addr,
const void *buf, size_t len)
{
struct rmi_i2c_xport *rmi_i2c =
container_of(xport, struct rmi_i2c_xport, xport);
struct i2c_client *client = rmi_i2c->client;
size_t tx_size = len + 1;
int retval;
mutex_lock(&rmi_i2c->page_mutex);
if (!rmi_i2c->tx_buf || rmi_i2c->tx_buf_size < tx_size) {
if (rmi_i2c->tx_buf)
devm_kfree(&client->dev, rmi_i2c->tx_buf);
rmi_i2c->tx_buf_size = tx_size + BUFFER_SIZE_INCREMENT;
rmi_i2c->tx_buf = devm_kzalloc(&client->dev,
rmi_i2c->tx_buf_size,
GFP_KERNEL);
if (!rmi_i2c->tx_buf) {
rmi_i2c->tx_buf_size = 0;
retval = -ENOMEM;
goto exit;
}
}
rmi_i2c->tx_buf[0] = addr & 0xff;
memcpy(rmi_i2c->tx_buf + 1, buf, len);
if (RMI_I2C_PAGE(addr) != rmi_i2c->page) {
retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr));
if (retval)
goto exit;
}
retval = i2c_master_send(client, rmi_i2c->tx_buf, tx_size);
if (retval == tx_size)
retval = 0;
else if (retval >= 0)
retval = -EIO;
exit:
rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
"write %zd bytes at %#06x: %d (%*ph)\n",
len, addr, retval, (int)len, buf);
mutex_unlock(&rmi_i2c->page_mutex);
return retval;
}
static int rmi_i2c_read_block(struct rmi_transport_dev *xport, u16 addr,
void *buf, size_t len)
{
struct rmi_i2c_xport *rmi_i2c =
container_of(xport, struct rmi_i2c_xport, xport);
struct i2c_client *client = rmi_i2c->client;
u8 addr_offset = addr & 0xff;
int retval;
struct i2c_msg msgs[] = {
{
.addr = client->addr,
.len = sizeof(addr_offset),
.buf = &addr_offset,
},
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = len,
.buf = buf,
},
};
mutex_lock(&rmi_i2c->page_mutex);
if (RMI_I2C_PAGE(addr) != rmi_i2c->page) {
retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr));
if (retval)
goto exit;
}
retval = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
if (retval == ARRAY_SIZE(msgs))
retval = 0; /* success */
else if (retval >= 0)
retval = -EIO;
exit:
rmi_dbg(RMI_DEBUG_XPORT, &client->dev,
"read %zd bytes at %#06x: %d (%*ph)\n",
len, addr, retval, (int)len, buf);
mutex_unlock(&rmi_i2c->page_mutex);
return retval;
}
static const struct rmi_transport_ops rmi_i2c_ops = {
.write_block = rmi_i2c_write_block,
.read_block = rmi_i2c_read_block,
};
#ifdef CONFIG_OF
static const struct of_device_id rmi_i2c_of_match[] = {
{ .compatible = "syna,rmi4-i2c" },
{},
};
MODULE_DEVICE_TABLE(of, rmi_i2c_of_match);
#endif
static void rmi_i2c_regulator_bulk_disable(void *data)
{
struct rmi_i2c_xport *rmi_i2c = data;
regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
rmi_i2c->supplies);
}
static void rmi_i2c_unregister_transport(void *data)
{
struct rmi_i2c_xport *rmi_i2c = data;
rmi_unregister_transport_device(&rmi_i2c->xport);
}
static int rmi_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct rmi_device_platform_data *pdata;
struct rmi_device_platform_data *client_pdata =
dev_get_platdata(&client->dev);
struct rmi_i2c_xport *rmi_i2c;
int retval;
rmi_i2c = devm_kzalloc(&client->dev, sizeof(struct rmi_i2c_xport),
GFP_KERNEL);
if (!rmi_i2c)
return -ENOMEM;
pdata = &rmi_i2c->xport.pdata;
if (!client->dev.of_node && client_pdata)
*pdata = *client_pdata;
pdata->irq = client->irq;
rmi_dbg(RMI_DEBUG_XPORT, &client->dev, "Probing %s.\n",
dev_name(&client->dev));
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
dev_err(&client->dev,
"adapter does not support required functionality.\n");
return -ENODEV;
}
rmi_i2c->supplies[0].supply = "vdd";
rmi_i2c->supplies[1].supply = "vio";
retval = devm_regulator_bulk_get(&client->dev,
ARRAY_SIZE(rmi_i2c->supplies),
rmi_i2c->supplies);
if (retval < 0)
return retval;
retval = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
rmi_i2c->supplies);
if (retval < 0)
return retval;
retval = devm_add_action_or_reset(&client->dev,
rmi_i2c_regulator_bulk_disable,
rmi_i2c);
if (retval)
return retval;
of_property_read_u32(client->dev.of_node, "syna,startup-delay-ms",
&rmi_i2c->startup_delay);
msleep(rmi_i2c->startup_delay);
rmi_i2c->client = client;
mutex_init(&rmi_i2c->page_mutex);
rmi_i2c->xport.dev = &client->dev;
rmi_i2c->xport.proto_name = "i2c";
rmi_i2c->xport.ops = &rmi_i2c_ops;
i2c_set_clientdata(client, rmi_i2c);
/*
* Setting the page to zero will (a) make sure the PSR is in a
* known state, and (b) make sure we can talk to the device.
*/
retval = rmi_set_page(rmi_i2c, 0);
if (retval) {
dev_err(&client->dev, "Failed to set page select to 0.\n");
return retval;
}
retval = rmi_register_transport_device(&rmi_i2c->xport);
if (retval) {
dev_err(&client->dev, "Failed to register transport driver at 0x%.2X.\n",
client->addr);
return retval;
}
retval = devm_add_action_or_reset(&client->dev,
rmi_i2c_unregister_transport,
rmi_i2c);
if (retval)
return retval;
dev_info(&client->dev, "registered rmi i2c driver at %#04x.\n",
client->addr);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int rmi_i2c_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
int ret;
ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev, true);
if (ret)
dev_warn(dev, "Failed to resume device: %d\n", ret);
regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
rmi_i2c->supplies);
return ret;
}
static int rmi_i2c_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
int ret;
ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
rmi_i2c->supplies);
if (ret)
return ret;
msleep(rmi_i2c->startup_delay);
ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev, true);
if (ret)
dev_warn(dev, "Failed to resume device: %d\n", ret);
return ret;
}
#endif
#ifdef CONFIG_PM
static int rmi_i2c_runtime_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
int ret;
ret = rmi_driver_suspend(rmi_i2c->xport.rmi_dev, false);
if (ret)
dev_warn(dev, "Failed to resume device: %d\n", ret);
regulator_bulk_disable(ARRAY_SIZE(rmi_i2c->supplies),
rmi_i2c->supplies);
return 0;
}
static int rmi_i2c_runtime_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct rmi_i2c_xport *rmi_i2c = i2c_get_clientdata(client);
int ret;
ret = regulator_bulk_enable(ARRAY_SIZE(rmi_i2c->supplies),
rmi_i2c->supplies);
if (ret)
return ret;
msleep(rmi_i2c->startup_delay);
ret = rmi_driver_resume(rmi_i2c->xport.rmi_dev, false);
if (ret)
dev_warn(dev, "Failed to resume device: %d\n", ret);
return 0;
}
#endif
static const struct dev_pm_ops rmi_i2c_pm = {
SET_SYSTEM_SLEEP_PM_OPS(rmi_i2c_suspend, rmi_i2c_resume)
SET_RUNTIME_PM_OPS(rmi_i2c_runtime_suspend, rmi_i2c_runtime_resume,
NULL)
};
static const struct i2c_device_id rmi_id[] = {
{ "rmi4_i2c", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, rmi_id);
static struct i2c_driver rmi_i2c_driver = {
.driver = {
.name = "rmi4_i2c",
.pm = &rmi_i2c_pm,
.of_match_table = of_match_ptr(rmi_i2c_of_match),
},
.id_table = rmi_id,
.probe = rmi_i2c_probe,
};
module_i2c_driver(rmi_i2c_driver);
MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com>");
MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com>");
MODULE_DESCRIPTION("RMI I2C driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(RMI_DRIVER_VERSION);