1 // SPDX-License-Identifier: GPL-2.0-only
3  * HCI based Driver for Inside Secure microread NFC Chip - i2c layer
11 #include <linux/i2c.h>
43 				 * < 0 if hardware error occured (e.g. i2c err)
51 	print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET,	\
52 		       16, 1, (skb)->data, (skb)->len, 0);	\
61 	len = skb->len;  in microread_i2c_add_len_crc()
64 	for (i = 0; i < skb->len; i++)  in microread_i2c_add_len_crc()
65 		crc = crc ^ skb->data[i];  in microread_i2c_add_len_crc()
81 	for (i = 0; i < skb->len - 1; i++)  in check_crc()
82 		crc = crc ^ skb->data[i];  in check_crc()
84 	if (crc != skb->data[skb->len-1]) {  in check_crc()
85 		pr_err("CRC error 0x%x != 0x%x\n", crc, skb->data[skb->len-1]);  in check_crc()
87 		return -EPERM;  in check_crc()
106 	struct microread_i2c_phy *phy = phy_id;  in microread_i2c_write()  local
107 	struct i2c_client *client = phy->i2c_dev;  in microread_i2c_write()
109 	if (phy->hard_fault != 0)  in microread_i2c_write()
110 		return phy->hard_fault;  in microread_i2c_write()
116 	I2C_DUMP_SKB("i2c frame written", skb);  in microread_i2c_write()
118 	r = i2c_master_send(client, skb->data, skb->len);  in microread_i2c_write()
120 	if (r == -EREMOTEIO) {	/* Retry, chip was in standby */  in microread_i2c_write()
122 		r = i2c_master_send(client, skb->data, skb->len);  in microread_i2c_write()
126 		if (r != skb->len)  in microread_i2c_write()
127 			r = -EREMOTEIO;  in microread_i2c_write()
138 static int microread_i2c_read(struct microread_i2c_phy *phy,  in microread_i2c_read()  argument
143 	u8 tmp[MICROREAD_I2C_LLC_MAX_SIZE - 1];  in microread_i2c_read()
144 	struct i2c_client *client = phy->i2c_dev;  in microread_i2c_read()
148 		nfc_err(&client->dev, "cannot read len byte\n");  in microread_i2c_read()
149 		return -EREMOTEIO;  in microread_i2c_read()
154 		nfc_err(&client->dev, "invalid len byte\n");  in microread_i2c_read()
155 		r = -EBADMSG;  in microread_i2c_read()
161 		r = -ENOMEM;  in microread_i2c_read()
170 		return -EREMOTEIO;  in microread_i2c_read()
178 		r = -EBADMSG;  in microread_i2c_read()
183 	skb_trim(*skb, (*skb)->len - MICROREAD_I2C_FRAME_TAILROOM);  in microread_i2c_read()
191 		r = -EREMOTEIO;  in microread_i2c_read()
200 	struct microread_i2c_phy *phy = phy_id;  in microread_i2c_irq_thread_fn()  local
204 	if (!phy || irq != phy->i2c_dev->irq) {  in microread_i2c_irq_thread_fn()
209 	if (phy->hard_fault != 0)  in microread_i2c_irq_thread_fn()
212 	r = microread_i2c_read(phy, &skb);  in microread_i2c_irq_thread_fn()
213 	if (r == -EREMOTEIO) {  in microread_i2c_irq_thread_fn()
214 		phy->hard_fault = r;  in microread_i2c_irq_thread_fn()
216 		nfc_hci_recv_frame(phy->hdev, NULL);  in microread_i2c_irq_thread_fn()
219 	} else if ((r == -ENOMEM) || (r == -EBADMSG)) {  in microread_i2c_irq_thread_fn()
223 	nfc_hci_recv_frame(phy->hdev, skb);  in microread_i2c_irq_thread_fn()
236 	struct microread_i2c_phy *phy;  in microread_i2c_probe()  local
239 	phy = devm_kzalloc(&client->dev, sizeof(struct microread_i2c_phy),  in microread_i2c_probe()
241 	if (!phy)  in microread_i2c_probe()
242 		return -ENOMEM;  in microread_i2c_probe()
244 	i2c_set_clientdata(client, phy);  in microread_i2c_probe()
245 	phy->i2c_dev = client;  in microread_i2c_probe()
247 	r = request_threaded_irq(client->irq, NULL, microread_i2c_irq_thread_fn,  in microread_i2c_probe()
249 				 MICROREAD_I2C_DRIVER_NAME, phy);  in microread_i2c_probe()
251 		nfc_err(&client->dev, "Unable to register IRQ handler\n");  in microread_i2c_probe()
255 	r = microread_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,  in microread_i2c_probe()
258 			    MICROREAD_I2C_LLC_MAX_PAYLOAD, &phy->hdev);  in microread_i2c_probe()
265 	free_irq(client->irq, phy);  in microread_i2c_probe()
272 	struct microread_i2c_phy *phy = i2c_get_clientdata(client);  in microread_i2c_remove()  local
274 	microread_remove(phy->hdev);  in microread_i2c_remove()
276 	free_irq(client->irq, phy);  in microread_i2c_remove()
283 MODULE_DEVICE_TABLE(i2c, microread_i2c_id);