Permalink
Fetching contributors…
Cannot retrieve contributors at this time
307 lines (234 sloc) 6.55 KB
/*
* I2C Link Layer for Samsung S3FWRN5 NCI based Driver
*
* Copyright (C) 2015 Samsung Electrnoics
* Robert Baldyga <r.baldyga@samsung.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2 or later, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#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 "s3fwrn5.h"
#define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c"
#define S3FWRN5_I2C_MAX_PAYLOAD 32
#define S3FWRN5_EN_WAIT_TIME 150
struct s3fwrn5_i2c_phy {
struct i2c_client *i2c_dev;
struct nci_dev *ndev;
unsigned int gpio_en;
unsigned int gpio_fw_wake;
struct mutex mutex;
enum s3fwrn5_mode mode;
unsigned int irq_skip:1;
};
static void s3fwrn5_i2c_set_wake(void *phy_id, bool wake)
{
struct s3fwrn5_i2c_phy *phy = phy_id;
mutex_lock(&phy->mutex);
gpio_set_value(phy->gpio_fw_wake, wake);
msleep(S3FWRN5_EN_WAIT_TIME/2);
mutex_unlock(&phy->mutex);
}
static void s3fwrn5_i2c_set_mode(void *phy_id, enum s3fwrn5_mode mode)
{
struct s3fwrn5_i2c_phy *phy = phy_id;
mutex_lock(&phy->mutex);
if (phy->mode == mode)
goto out;
phy->mode = mode;
gpio_set_value(phy->gpio_en, 1);
gpio_set_value(phy->gpio_fw_wake, 0);
if (mode == S3FWRN5_MODE_FW)
gpio_set_value(phy->gpio_fw_wake, 1);
if (mode != S3FWRN5_MODE_COLD) {
msleep(S3FWRN5_EN_WAIT_TIME);
gpio_set_value(phy->gpio_en, 0);
msleep(S3FWRN5_EN_WAIT_TIME/2);
}
phy->irq_skip = true;
out:
mutex_unlock(&phy->mutex);
}
static enum s3fwrn5_mode s3fwrn5_i2c_get_mode(void *phy_id)
{
struct s3fwrn5_i2c_phy *phy = phy_id;
enum s3fwrn5_mode mode;
mutex_lock(&phy->mutex);
mode = phy->mode;
mutex_unlock(&phy->mutex);
return mode;
}
static int s3fwrn5_i2c_write(void *phy_id, struct sk_buff *skb)
{
struct s3fwrn5_i2c_phy *phy = phy_id;
int ret;
mutex_lock(&phy->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->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_i2c_set_wake,
.set_mode = s3fwrn5_i2c_set_mode,
.get_mode = s3fwrn5_i2c_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->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->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->ndev, skb, phy->mode);
}
static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id)
{
struct s3fwrn5_i2c_phy *phy = phy_id;
int ret = 0;
if (!phy || !phy->ndev) {
WARN_ON_ONCE(1);
return IRQ_NONE;
}
mutex_lock(&phy->mutex);
if (phy->irq_skip)
goto out;
switch (phy->mode) {
case S3FWRN5_MODE_NCI:
case S3FWRN5_MODE_FW:
ret = s3fwrn5_i2c_read(phy);
break;
case S3FWRN5_MODE_COLD:
ret = -EREMOTEIO;
break;
}
out:
mutex_unlock(&phy->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->gpio_en = of_get_named_gpio(np, "s3fwrn5,en-gpios", 0);
if (!gpio_is_valid(phy->gpio_en))
return -ENODEV;
phy->gpio_fw_wake = of_get_named_gpio(np, "s3fwrn5,fw-gpios", 0);
if (!gpio_is_valid(phy->gpio_fw_wake))
return -ENODEV;
return 0;
}
static int s3fwrn5_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct s3fwrn5_i2c_phy *phy;
int ret;
phy = devm_kzalloc(&client->dev, sizeof(*phy), GFP_KERNEL);
if (!phy)
return -ENOMEM;
mutex_init(&phy->mutex);
phy->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->gpio_en,
GPIOF_OUT_INIT_HIGH, "s3fwrn5_en");
if (ret < 0)
return ret;
ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw_wake,
GPIOF_OUT_INIT_LOW, "s3fwrn5_fw_wake");
if (ret < 0)
return ret;
ret = s3fwrn5_probe(&phy->ndev, phy, &phy->i2c_dev->dev, &i2c_phy_ops,
S3FWRN5_I2C_MAX_PAYLOAD);
if (ret < 0)
return ret;
ret = devm_request_threaded_irq(&client->dev, phy->i2c_dev->irq, NULL,
s3fwrn5_i2c_irq_thread_fn, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
S3FWRN5_I2C_DRIVER_NAME, phy);
if (ret)
s3fwrn5_remove(phy->ndev);
return ret;
}
static int s3fwrn5_i2c_remove(struct i2c_client *client)
{
struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client);
s3fwrn5_remove(phy->ndev);
return 0;
}
static const struct i2c_device_id s3fwrn5_i2c_id_table[] = {
{S3FWRN5_I2C_DRIVER_NAME, 0},
{}
};
MODULE_DEVICE_TABLE(i2c, s3fwrn5_i2c_id_table);
static const struct of_device_id of_s3fwrn5_i2c_match[] = {
{ .compatible = "samsung,s3fwrn5-i2c", },
{}
};
MODULE_DEVICE_TABLE(of, of_s3fwrn5_i2c_match);
static struct i2c_driver s3fwrn5_i2c_driver = {
.driver = {
.owner = THIS_MODULE,
.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 <r.baldyga@samsung.com>");