diff options
Diffstat (limited to 'drivers/nfc/s3fwrn5/i2c.c')
| -rw-r--r-- | drivers/nfc/s3fwrn5/i2c.c | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/drivers/nfc/s3fwrn5/i2c.c b/drivers/nfc/s3fwrn5/i2c.c new file mode 100644 index 000000000..b4dd7dd47 --- /dev/null +++ b/drivers/nfc/s3fwrn5/i2c.c @@ -0,0 +1,306 @@ +/* + * 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 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; + + memcpy(skb_put(skb, hdr_size), 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 = request_threaded_irq(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 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>"); |