// SPDX-License-Identifier: GPL-2.0-or-later
/*
* I2C Link Layer for Samsung S3FWRN5 NCI based Driver
*
* Copyright (C) 2015 Samsung Electrnoics
* Robert Baldyga <[email protected]>
*/
#include <linux/clk.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/module.h>
#include <net/nfc/nfc.h>
#include "phy_common.h"
#define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c"
struct s3fwrn5_i2c_phy {
struct phy_common common;
struct i2c_client *i2c_dev;
struct clk *clk;
unsigned int irq_skip:1;
};
static void s3fwrn5_i2c_set_mode(void *phy_id, enum s3fwrn5_mode mode)
{
struct s3fwrn5_i2c_phy *phy = phy_id;
mutex_lock(&phy->common.mutex);
if (s3fwrn5_phy_power_ctrl(&phy->common, mode) == false)
goto out;
phy->irq_skip = true;
out:
mutex_unlock(&phy->common.mutex);
}
static int s3fwrn5_i2c_write(void *phy_id, struct sk_buff *skb)
{
struct s3fwrn5_i2c_phy *phy = phy_id;
int ret;
mutex_lock(&phy->common.mutex);
phy->irq_skip = false;
ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
if (ret == -EREMOTEIO) {
/* Retry, chip was in standby */
usleep_range(110000, 120000);
ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len);
}
mutex_unlock(&phy->common.mutex);
if (ret < 0)
return ret;
if (ret != skb->len)
return -EREMOTEIO;
return 0;
}
static const struct s3fwrn5_phy_ops i2c_phy_ops = {
.set_wake = s3fwrn5_phy_set_wake,
.set_mode = s3fwrn5_i2c_set_mode,
.get_mode = s3fwrn5_phy_get_mode,
.write = s3fwrn5_i2c_write,
};
static int s3fwrn5_i2c_read(struct s3fwrn5_i2c_phy *phy)
{
struct sk_buff *skb;
size_t hdr_size;
size_t data_len;
char hdr[4];
int ret;
hdr_size = (phy->common.mode == S3FWRN5_MODE_NCI) ?
NCI_CTRL_HDR_SIZE : S3FWRN5_FW_HDR_SIZE;
ret = i2c_master_recv(phy->i2c_dev, hdr, hdr_size);
if (ret < 0)
return ret;
if (ret < hdr_size)
return -EBADMSG;
data_len = (phy->common.mode == S3FWRN5_MODE_NCI) ?
((struct nci_ctrl_hdr *)hdr)->plen :
((struct s3fwrn5_fw_header *)hdr)->len;
skb = alloc_skb(hdr_size + data_len, GFP_KERNEL);
if (!skb)
return -ENOMEM;
skb_put_data(skb, hdr, hdr_size);
if (data_len == 0)
goto out;
ret = i2c_master_recv(phy->i2c_dev, skb_put(skb, data_len), data_len);
if (ret != data_len) {
kfree_skb(skb);
return -EBADMSG;
}
out:
return s3fwrn5_recv_frame(phy->common.ndev, skb, phy->common.mode);
}
static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id)
{
struct s3fwrn5_i2c_phy *phy = phy_id;
if (!phy || !phy->common.ndev) {
WARN_ON_ONCE(1);
return IRQ_NONE;
}
mutex_lock(&phy->common.mutex);
if (phy->irq_skip)
goto out;
switch (phy->common.mode) {
case S3FWRN5_MODE_NCI:
case S3FWRN5_MODE_FW:
s3fwrn5_i2c_read(phy);
break;
case S3FWRN5_MODE_COLD:
break;
}
out:
mutex_unlock(&phy->common.mutex);
return IRQ_HANDLED;
}
static int s3fwrn5_i2c_parse_dt(struct i2c_client *client)
{
struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
struct device_node *np = client->dev.of_node;
if (!np)
return -ENODEV;
phy->common.gpio_en = of_get_named_gpio(np, "en-gpios", 0);
if (!gpio_is_valid(phy->common.gpio_en)) {
/* Support also deprecated property */
phy->common.gpio_en = of_get_named_gpio(np,
"s3fwrn5,en-gpios",
0);
if (!gpio_is_valid(phy->common.gpio_en))
return -ENODEV;
}
phy->common.gpio_fw_wake = of_get_named_gpio(np, "wake-gpios", 0);
if (!gpio_is_valid(phy->common.gpio_fw_wake)) {
/* Support also deprecated property */
phy->common.gpio_fw_wake = of_get_named_gpio(np,
"s3fwrn5,fw-gpios",
0);
if (!gpio_is_valid(phy->common.gpio_fw_wake))
return -ENODEV;
}
return 0;
}
static int s3fwrn5_i2c_probe(struct i2c_client *client)
{
struct s3fwrn5_i2c_phy *phy;
int ret;
phy = devm_kzalloc(&client->dev, sizeof(*phy), GFP_KERNEL);
if (!phy)
return -ENOMEM;
mutex_init(&phy->common.mutex);
phy->common.mode = S3FWRN5_MODE_COLD;
phy->irq_skip = true;
phy->i2c_dev = client;
i2c_set_clientdata(client, phy);
ret = s3fwrn5_i2c_parse_dt(client);
if (ret < 0)
return ret;
ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->common.gpio_en,
GPIOF_OUT_INIT_HIGH, "s3fwrn5_en");
if (ret < 0)
return ret;
ret = devm_gpio_request_one(&phy->i2c_dev->dev,
phy->common.gpio_fw_wake,
GPIOF_OUT_INIT_LOW, "s3fwrn5_fw_wake");
if (ret < 0)
return ret;
/*
* S3FWRN5 depends on a clock input ("XI" pin) to function properly.
* Depending on the hardware configuration this could be an always-on
* oscillator or some external clock that must be explicitly enabled.
* Make sure the clock is running before starting S3FWRN5.
*/
phy->clk = devm_clk_get_optional_enabled(&client->dev, NULL);
if (IS_ERR(phy->clk))
return dev_err_probe(&client->dev, PTR_ERR(phy->clk),
"failed to get clock\n");
ret = s3fwrn5_probe(&phy->common.ndev, phy, &phy->i2c_dev->dev,
&i2c_phy_ops);
if (ret < 0)
return ret;
ret = devm_request_threaded_irq(&client->dev, phy->i2c_dev->irq, NULL,
s3fwrn5_i2c_irq_thread_fn, IRQF_ONESHOT,
S3FWRN5_I2C_DRIVER_NAME, phy);
if (ret)
goto s3fwrn5_remove;
return 0;
s3fwrn5_remove:
s3fwrn5_remove(phy->common.ndev);
return ret;
}
static void s3fwrn5_i2c_remove(struct i2c_client *client)
{
struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
s3fwrn5_remove(phy->common.ndev);
}
static const struct i2c_device_id s3fwrn5_i2c_id_table[] = {
{ S3FWRN5_I2C_DRIVER_NAME },
{}
};
MODULE_DEVICE_TABLE(i2c, s3fwrn5_i2c_id_table);
static const struct of_device_id of_s3fwrn5_i2c_match[] __maybe_unused = {
{ .compatible = "samsung,s3fwrn5-i2c", },
{}
};
MODULE_DEVICE_TABLE(of, of_s3fwrn5_i2c_match);
static struct i2c_driver s3fwrn5_i2c_driver = {
.driver = {
.name = S3FWRN5_I2C_DRIVER_NAME,
.of_match_table = of_match_ptr(of_s3fwrn5_i2c_match),
},
.probe = s3fwrn5_i2c_probe,
.remove = s3fwrn5_i2c_remove,
.id_table = s3fwrn5_i2c_id_table,
};
module_i2c_driver(s3fwrn5_i2c_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("I2C driver for Samsung S3FWRN5");
MODULE_AUTHOR("Robert Baldyga <[email protected]>");
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