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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.c273
1 files changed, 273 insertions, 0 deletions
diff --git a/drivers/nfc/s3fwrn5/i2c.c b/drivers/nfc/s3fwrn5/i2c.c
new file mode 100644
index 0000000000..720d4a7249
--- /dev/null
+++ b/drivers/nfc/s3fwrn5/i2c.c
@@ -0,0 +1,273 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * I2C Link Layer for Samsung S3FWRN5 NCI based Driver
+ *
+ * Copyright (C) 2015 Samsung Electrnoics
+ * Robert Baldyga <r.baldyga@samsung.com>
+ */
+
+#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, 0},
+ {}
+};
+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 <r.baldyga@samsung.com>");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-20 03:59:21 +0000