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path: root/drivers/nfc/s3fwrn5/i2c.c
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Diffstat (limited to 'drivers/nfc/s3fwrn5/i2c.c')
-rw-r--r--drivers/nfc/s3fwrn5/i2c.c306
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>");