nfc: st-nci: Rename st21nfcb to st-nci

STMicroelectronics NFC NCI chips family is extending
with the new ST21NFCC using the AMS AS39230 RF booster.
The st21nfcb driver is relevant for this solution and
might be with future products.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 385 insertions, 0 deletions

diff --git a/drivers/nfc/st-nci/i2c.c b/drivers/nfc/st-nci/i2c.c
new file mode 100644
index 000000000000..06175ce769bb
--- /dev/null
+++ b/drivers/nfc/st-nci/i2c.c
@@ -0,0 +1,385 @@
+/*
+ * I2C Link Layer for ST NCI NFC controller familly based Driver
+ * Copyright (C) 2014-2015 STMicroelectronics SAS. All rights reserved.
+ *
+ * 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, 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/>.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/of_irq.h>
+#include <linux/of_gpio.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/nfc.h>
+#include <linux/platform_data/st_nci.h>
+
+#include "ndlc.h"
+
+#define DRIVER_DESC "NCI NFC driver for ST21NFCB"
+
+/* ndlc header */
+#define ST21NFCB_FRAME_HEADROOM	1
+#define ST21NFCB_FRAME_TAILROOM 0
+
+#define ST_NCI_I2C_MIN_SIZE 4   /* PCB(1) + NCI Packet header(3) */
+#define ST_NCI_I2C_MAX_SIZE 250 /* req 4.2.1 */
+
+#define ST_NCI_I2C_DRIVER_NAME "st_nci_i2c"
+
+static struct i2c_device_id st_nci_i2c_id_table[] = {
+	{ST_NCI_DRIVER_NAME, 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, st_nci_i2c_id_table);
+
+struct st_nci_i2c_phy {
+	struct i2c_client *i2c_dev;
+	struct llt_ndlc *ndlc;
+
+	unsigned int gpio_reset;
+	unsigned int irq_polarity;
+};
+
+#define I2C_DUMP_SKB(info, skb)					\
+do {								\
+	pr_debug("%s:\n", info);				\
+	print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET,	\
+		       16, 1, (skb)->data, (skb)->len, 0);	\
+} while (0)
+
+static int st_nci_i2c_enable(void *phy_id)
+{
+	struct st_nci_i2c_phy *phy = phy_id;
+
+	gpio_set_value(phy->gpio_reset, 0);
+	usleep_range(10000, 15000);
+	gpio_set_value(phy->gpio_reset, 1);
+	usleep_range(80000, 85000);
+
+	if (phy->ndlc->powered == 0)
+		enable_irq(phy->i2c_dev->irq);
+
+	return 0;
+}
+
+static void st_nci_i2c_disable(void *phy_id)
+{
+	struct st_nci_i2c_phy *phy = phy_id;
+
+	disable_irq_nosync(phy->i2c_dev->irq);
+}
+
+/*
+ * Writing a frame must not return the number of written bytes.
+ * It must return either zero for success, or <0 for error.
+ * In addition, it must not alter the skb
+ */
+static int st_nci_i2c_write(void *phy_id, struct sk_buff *skb)
+{
+	int r = -1;
+	struct st_nci_i2c_phy *phy = phy_id;
+	struct i2c_client *client = phy->i2c_dev;
+
+	I2C_DUMP_SKB("st_nci_i2c_write", skb);
+
+	if (phy->ndlc->hard_fault != 0)
+		return phy->ndlc->hard_fault;
+
+	r = i2c_master_send(client, skb->data, skb->len);
+	if (r < 0) {  /* Retry, chip was in standby */
+		usleep_range(1000, 4000);
+		r = i2c_master_send(client, skb->data, skb->len);
+	}
+
+	if (r >= 0) {
+		if (r != skb->len)
+			r = -EREMOTEIO;
+		else
+			r = 0;
+	}
+
+	return r;
+}
+
+/*
+ * Reads an ndlc frame and returns it in a newly allocated sk_buff.
+ * returns:
+ * frame size : if received frame is complete (find ST21NFCB_SOF_EOF at
+ * end of read)
+ * -EAGAIN : if received frame is incomplete (not find ST21NFCB_SOF_EOF
+ * at end of read)
+ * -EREMOTEIO : i2c read error (fatal)
+ * -EBADMSG : frame was incorrect and discarded
+ * (value returned from st_nci_i2c_repack)
+ * -EIO : if no ST21NFCB_SOF_EOF is found after reaching
+ * the read length end sequence
+ */
+static int st_nci_i2c_read(struct st_nci_i2c_phy *phy,
+				 struct sk_buff **skb)
+{
+	int r;
+	u8 len;
+	u8 buf[ST_NCI_I2C_MAX_SIZE];
+	struct i2c_client *client = phy->i2c_dev;
+
+	r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE);
+	if (r < 0) {  /* Retry, chip was in standby */
+		usleep_range(1000, 4000);
+		r = i2c_master_recv(client, buf, ST_NCI_I2C_MIN_SIZE);
+	}
+
+	if (r != ST_NCI_I2C_MIN_SIZE)
+		return -EREMOTEIO;
+
+	len = be16_to_cpu(*(__be16 *) (buf + 2));
+	if (len > ST_NCI_I2C_MAX_SIZE) {
+		nfc_err(&client->dev, "invalid frame len\n");
+		return -EBADMSG;
+	}
+
+	*skb = alloc_skb(ST_NCI_I2C_MIN_SIZE + len, GFP_KERNEL);
+	if (*skb == NULL)
+		return -ENOMEM;
+
+	skb_reserve(*skb, ST_NCI_I2C_MIN_SIZE);
+	skb_put(*skb, ST_NCI_I2C_MIN_SIZE);
+	memcpy((*skb)->data, buf, ST_NCI_I2C_MIN_SIZE);
+
+	if (!len)
+		return 0;
+
+	r = i2c_master_recv(client, buf, len);
+	if (r != len) {
+		kfree_skb(*skb);
+		return -EREMOTEIO;
+	}
+
+	skb_put(*skb, len);
+	memcpy((*skb)->data + ST_NCI_I2C_MIN_SIZE, buf, len);
+
+	I2C_DUMP_SKB("i2c frame read", *skb);
+
+	return 0;
+}
+
+/*
+ * Reads an ndlc frame from the chip.
+ *
+ * On ST21NFCB, IRQ goes in idle state when read starts.
+ */
+static irqreturn_t st_nci_irq_thread_fn(int irq, void *phy_id)
+{
+	struct st_nci_i2c_phy *phy = phy_id;
+	struct i2c_client *client;
+	struct sk_buff *skb = NULL;
+	int r;
+
+	if (!phy || !phy->ndlc || irq != phy->i2c_dev->irq) {
+		WARN_ON_ONCE(1);
+		return IRQ_NONE;
+	}
+
+	client = phy->i2c_dev;
+	dev_dbg(&client->dev, "IRQ\n");
+
+	if (phy->ndlc->hard_fault)
+		return IRQ_HANDLED;
+
+	if (!phy->ndlc->powered) {
+		st_nci_i2c_disable(phy);
+		return IRQ_HANDLED;
+	}
+
+	r = st_nci_i2c_read(phy, &skb);
+	if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
+		return IRQ_HANDLED;
+
+	ndlc_recv(phy->ndlc, skb);
+
+	return IRQ_HANDLED;
+}
+
+static struct nfc_phy_ops i2c_phy_ops = {
+	.write = st_nci_i2c_write,
+	.enable = st_nci_i2c_enable,
+	.disable = st_nci_i2c_disable,
+};
+
+#ifdef CONFIG_OF
+static int st_nci_i2c_of_request_resources(struct i2c_client *client)
+{
+	struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
+	struct device_node *pp;
+	int gpio;
+	int r;
+
+	pp = client->dev.of_node;
+	if (!pp)
+		return -ENODEV;
+
+	/* Get GPIO from device tree */
+	gpio = of_get_named_gpio(pp, "reset-gpios", 0);
+	if (gpio < 0) {
+		nfc_err(&client->dev,
+			"Failed to retrieve reset-gpios from device tree\n");
+		return gpio;
+	}
+
+	/* GPIO request and configuration */
+	r = devm_gpio_request_one(&client->dev, gpio,
+				GPIOF_OUT_INIT_HIGH, "clf_reset");
+	if (r) {
+		nfc_err(&client->dev, "Failed to request reset pin\n");
+		return r;
+	}
+	phy->gpio_reset = gpio;
+
+	phy->irq_polarity = irq_get_trigger_type(client->irq);
+
+	return 0;
+}
+#else
+static int st_nci_i2c_of_request_resources(struct i2c_client *client)
+{
+	return -ENODEV;
+}
+#endif
+
+static int st_nci_i2c_request_resources(struct i2c_client *client)
+{
+	struct st_nci_nfc_platform_data *pdata;
+	struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
+	int r;
+
+	pdata = client->dev.platform_data;
+	if (pdata == NULL) {
+		nfc_err(&client->dev, "No platform data\n");
+		return -EINVAL;
+	}
+
+	/* store for later use */
+	phy->gpio_reset = pdata->gpio_reset;
+	phy->irq_polarity = pdata->irq_polarity;
+
+	r = devm_gpio_request_one(&client->dev,
+			phy->gpio_reset, GPIOF_OUT_INIT_HIGH, "clf_reset");
+	if (r) {
+		pr_err("%s : reset gpio_request failed\n", __FILE__);
+		return r;
+	}
+
+	return 0;
+}
+
+static int st_nci_i2c_probe(struct i2c_client *client,
+				  const struct i2c_device_id *id)
+{
+	struct st_nci_i2c_phy *phy;
+	struct st_nci_nfc_platform_data *pdata;
+	int r;
+
+	dev_dbg(&client->dev, "%s\n", __func__);
+	dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
+		return -ENODEV;
+	}
+
+	phy = devm_kzalloc(&client->dev, sizeof(struct st_nci_i2c_phy),
+			   GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	phy->i2c_dev = client;
+
+	i2c_set_clientdata(client, phy);
+
+	pdata = client->dev.platform_data;
+	if (!pdata && client->dev.of_node) {
+		r = st_nci_i2c_of_request_resources(client);
+		if (r) {
+			nfc_err(&client->dev, "No platform data\n");
+			return r;
+		}
+	} else if (pdata) {
+		r = st_nci_i2c_request_resources(client);
+		if (r) {
+			nfc_err(&client->dev,
+				"Cannot get platform resources\n");
+			return r;
+		}
+	} else {
+		nfc_err(&client->dev,
+			"st21nfcb platform resources not available\n");
+		return -ENODEV;
+	}
+
+	r = ndlc_probe(phy, &i2c_phy_ops, &client->dev,
+			ST21NFCB_FRAME_HEADROOM, ST21NFCB_FRAME_TAILROOM,
+			&phy->ndlc);
+	if (r < 0) {
+		nfc_err(&client->dev, "Unable to register ndlc layer\n");
+		return r;
+	}
+
+	r = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+				st_nci_irq_thread_fn,
+				phy->irq_polarity | IRQF_ONESHOT,
+				ST_NCI_DRIVER_NAME, phy);
+	if (r < 0)
+		nfc_err(&client->dev, "Unable to register IRQ handler\n");
+
+	return r;
+}
+
+static int st_nci_i2c_remove(struct i2c_client *client)
+{
+	struct st_nci_i2c_phy *phy = i2c_get_clientdata(client);
+
+	dev_dbg(&client->dev, "%s\n", __func__);
+
+	ndlc_remove(phy->ndlc);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id of_st_nci_i2c_match[] = {
+	{ .compatible = "st,st21nfcb-i2c", },
+	{ .compatible = "st,st21nfcb_i2c", },
+	{ .compatible = "st,st21nfcc-i2c", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_st_nci_i2c_match);
+#endif
+
+static struct i2c_driver st_nci_i2c_driver = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = ST_NCI_I2C_DRIVER_NAME,
+		.of_match_table = of_match_ptr(of_st_nci_i2c_match),
+	},
+	.probe = st_nci_i2c_probe,
+	.id_table = st_nci_i2c_id_table,
+	.remove = st_nci_i2c_remove,
+};
+
+module_i2c_driver(st_nci_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION(DRIVER_DESC);