--- /dev/null
+/* -------------------------------------------------------------------------
+ * Copyright (C) 2014-2016, Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ * -------------------------------------------------------------------------
+ */
+
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/nfc.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <net/nfc/nfc.h>
+#include <net/nfc/nci_core.h>
+
+#include "fdp.h"
+
+#define FDP_I2C_DRIVER_NAME "fdp_nci_i2c"
+
+#define FDP_DP_POWER_GPIO_NAME "power"
+#define FDP_DP_CLOCK_TYPE_NAME "clock-type"
+#define FDP_DP_CLOCK_FREQ_NAME "clock-freq"
+#define FDP_DP_FW_VSC_CFG_NAME "fw-vsc-cfg"
+
+#define FDP_FRAME_HEADROOM 2
+#define FDP_FRAME_TAILROOM 1
+
+#define FDP_NCI_I2C_MIN_PAYLOAD 5
+#define FDP_NCI_I2C_MAX_PAYLOAD 261
+
+#define FDP_POWER_OFF 0
+#define FDP_POWER_ON 1
+
+#define fdp_nci_i2c_dump_skb(dev, prefix, skb) \
+ print_hex_dump(KERN_DEBUG, prefix": ", DUMP_PREFIX_OFFSET, \
+ 16, 1, (skb)->data, (skb)->len, 0)
+
+static void fdp_nci_i2c_reset(struct fdp_i2c_phy *phy)
+{
+ /* Reset RST/WakeUP for at least 100 micro-second */
+ gpiod_set_value_cansleep(phy->power_gpio, FDP_POWER_OFF);
+ usleep_range(1000, 4000);
+ gpiod_set_value_cansleep(phy->power_gpio, FDP_POWER_ON);
+ usleep_range(10000, 14000);
+}
+
+static int fdp_nci_i2c_enable(void *phy_id)
+{
+ struct fdp_i2c_phy *phy = phy_id;
+
+ dev_dbg(&phy->i2c_dev->dev, "%s\n", __func__);
+ fdp_nci_i2c_reset(phy);
+
+ return 0;
+}
+
+static void fdp_nci_i2c_disable(void *phy_id)
+{
+ struct fdp_i2c_phy *phy = phy_id;
+
+ dev_dbg(&phy->i2c_dev->dev, "%s\n", __func__);
+ fdp_nci_i2c_reset(phy);
+}
+
+static void fdp_nci_i2c_add_len_lrc(struct sk_buff *skb)
+{
+ u8 lrc = 0;
+ u16 len, i;
+
+ /* Add length header */
+ len = skb->len;
+ *skb_push(skb, 1) = len & 0xff;
+ *skb_push(skb, 1) = len >> 8;
+
+ /* Compute and add lrc */
+ for (i = 0; i < len + 2; i++)
+ lrc ^= skb->data[i];
+
+ *skb_put(skb, 1) = lrc;
+}
+
+static void fdp_nci_i2c_remove_len_lrc(struct sk_buff *skb)
+{
+ skb_pull(skb, FDP_FRAME_HEADROOM);
+ skb_trim(skb, skb->len - FDP_FRAME_TAILROOM);
+}
+
+static int fdp_nci_i2c_write(void *phy_id, struct sk_buff *skb)
+{
+ struct fdp_i2c_phy *phy = phy_id;
+ struct i2c_client *client = phy->i2c_dev;
+ int r;
+
+ if (phy->hard_fault != 0)
+ return phy->hard_fault;
+
+ fdp_nci_i2c_add_len_lrc(skb);
+ fdp_nci_i2c_dump_skb(&client->dev, "fdp_wr", skb);
+
+ r = i2c_master_send(client, skb->data, skb->len);
+ if (r == -EREMOTEIO) { /* Retry, chip was in standby */
+ usleep_range(1000, 4000);
+ r = i2c_master_send(client, skb->data, skb->len);
+ }
+
+ if (r < 0 || r != skb->len)
+ dev_dbg(&client->dev, "%s: error err=%d len=%d\n",
+ __func__, r, skb->len);
+
+ if (r >= 0) {
+ if (r != skb->len) {
+ phy->hard_fault = r;
+ r = -EREMOTEIO;
+ } else {
+ r = 0;
+ }
+ }
+
+ fdp_nci_i2c_remove_len_lrc(skb);
+
+ return r;
+}
+
+static struct nfc_phy_ops i2c_phy_ops = {
+ .write = fdp_nci_i2c_write,
+ .enable = fdp_nci_i2c_enable,
+ .disable = fdp_nci_i2c_disable,
+};
+
+static int fdp_nci_i2c_read(struct fdp_i2c_phy *phy, struct sk_buff **skb)
+{
+ int r, len;
+ u8 tmp[FDP_NCI_I2C_MAX_PAYLOAD], lrc, k;
+ u16 i;
+ struct i2c_client *client = phy->i2c_dev;
+
+ *skb = NULL;
+
+ /* Read the length packet and the data packet */
+ for (k = 0; k < 2; k++) {
+
+ len = phy->next_read_size;
+
+ r = i2c_master_recv(client, tmp, len);
+ if (r != len) {
+ dev_dbg(&client->dev, "%s: i2c recv err: %d\n",
+ __func__, r);
+ goto flush;
+ }
+
+ /* Check packet integruty */
+ for (lrc = i = 0; i < r; i++)
+ lrc ^= tmp[i];
+
+ /*
+ * LRC check failed. This may due to transmission error or
+ * desynchronization between driver and FDP. Drop the paquet
+ * and force resynchronization
+ */
+ if (lrc) {
+ dev_dbg(&client->dev, "%s: corrupted packet\n",
+ __func__);
+ phy->next_read_size = 5;
+ goto flush;
+ }
+
+ /* Packet that contains a length */
+ if (tmp[0] == 0 && tmp[1] == 0) {
+ phy->next_read_size = (tmp[2] << 8) + tmp[3] + 3;
+ } else {
+ phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD;
+
+ *skb = alloc_skb(len, GFP_KERNEL);
+ if (*skb == NULL) {
+ r = -ENOMEM;
+ goto flush;
+ }
+
+ memcpy(skb_put(*skb, len), tmp, len);
+ fdp_nci_i2c_dump_skb(&client->dev, "fdp_rd", *skb);
+
+ fdp_nci_i2c_remove_len_lrc(*skb);
+ }
+ }
+
+ return 0;
+
+flush:
+ /* Flush the remaining data */
+ if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0)
+ r = -EREMOTEIO;
+
+ return r;
+}
+
+static irqreturn_t fdp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
+{
+ struct fdp_i2c_phy *phy = phy_id;
+ struct i2c_client *client;
+ struct sk_buff *skb;
+ int r;
+
+ client = phy->i2c_dev;
+ dev_dbg(&client->dev, "%s\n", __func__);
+
+ if (!phy || irq != phy->i2c_dev->irq) {
+ WARN_ON_ONCE(1);
+ return IRQ_NONE;
+ }
+
+ r = fdp_nci_i2c_read(phy, &skb);
+
+ if (r == -EREMOTEIO)
+ return IRQ_HANDLED;
+ else if (r == -ENOMEM || r == -EBADMSG)
+ return IRQ_HANDLED;
+
+ if (skb != NULL)
+ fdp_nci_recv_frame(phy->ndev, skb);
+
+ return IRQ_HANDLED;
+}
+
+static void fdp_nci_i2c_read_device_properties(struct device *dev,
+ u8 *clock_type, u32 *clock_freq,
+ u8 **fw_vsc_cfg)
+{
+ int r;
+ u8 len;
+
+ r = device_property_read_u8(dev, FDP_DP_CLOCK_TYPE_NAME, clock_type);
+ if (r) {
+ dev_dbg(dev, "Using default clock type");
+ *clock_type = 0;
+ }
+
+ r = device_property_read_u32(dev, FDP_DP_CLOCK_FREQ_NAME, clock_freq);
+ if (r) {
+ dev_dbg(dev, "Using default clock frequency\n");
+ *clock_freq = 26000;
+ }
+
+ if (device_property_present(dev, FDP_DP_FW_VSC_CFG_NAME)) {
+ r = device_property_read_u8(dev, FDP_DP_FW_VSC_CFG_NAME,
+ &len);
+
+ if (r || len <= 0)
+ goto vsc_read_err;
+
+ /* Add 1 to the length to inclue the length byte itself */
+ len++;
+
+ *fw_vsc_cfg = devm_kmalloc(dev,
+ len * sizeof(**fw_vsc_cfg),
+ GFP_KERNEL);
+
+ r = device_property_read_u8_array(dev, FDP_DP_FW_VSC_CFG_NAME,
+ *fw_vsc_cfg, len);
+
+ if (r) {
+ devm_kfree(dev, fw_vsc_cfg);
+ goto vsc_read_err;
+ }
+ } else {
+vsc_read_err:
+ dev_dbg(dev, "FW vendor specific commands not present\n");
+ *fw_vsc_cfg = NULL;
+ }
+
+ dev_dbg(dev, "Clock type: %d, clock frequency: %d, VSC: %s",
+ *clock_type, *clock_freq, *fw_vsc_cfg != NULL ? "yes" : "no");
+}
+
+static int fdp_nci_i2c_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct fdp_i2c_phy *phy;
+ struct device *dev = &client->dev;
+ u8 *fw_vsc_cfg;
+ u8 clock_type;
+ u32 clock_freq;
+ int r = 0;
+
+ dev_dbg(dev, "%s\n", __func__);
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ nfc_err(dev, "No I2C_FUNC_I2C support\n");
+ return -ENODEV;
+ }
+
+ phy = devm_kzalloc(dev, sizeof(struct fdp_i2c_phy),
+ GFP_KERNEL);
+ if (!phy)
+ return -ENOMEM;
+
+ phy->i2c_dev = client;
+ phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD;
+ i2c_set_clientdata(client, phy);
+
+ /* Checking if we have an irq */
+ if (client->irq <= 0) {
+ dev_err(dev, "IRQ not present\n");
+ return -ENODEV;
+ }
+
+ r = request_threaded_irq(client->irq, NULL, fdp_nci_i2c_irq_thread_fn,
+ IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+ FDP_I2C_DRIVER_NAME, phy);
+
+ if (r < 0) {
+ nfc_err(&client->dev, "Unable to register IRQ handler\n");
+ return r;
+ }
+
+ /* Requesting the power gpio */
+ phy->power_gpio = devm_gpiod_get(dev, FDP_DP_POWER_GPIO_NAME,
+ GPIOD_OUT_LOW);
+
+ if (IS_ERR(phy->power_gpio)) {
+ nfc_err(dev, "Power GPIO request failed\n");
+ return PTR_ERR(phy->power_gpio);
+ }
+
+ /* read device properties to get the clock and production settings */
+ fdp_nci_i2c_read_device_properties(dev, &clock_type, &clock_freq,
+ &fw_vsc_cfg);
+
+ /* Call the NFC specific probe function */
+ r = fdp_nci_probe(phy, &i2c_phy_ops, &phy->ndev,
+ FDP_FRAME_HEADROOM, FDP_FRAME_TAILROOM,
+ clock_type, clock_freq, fw_vsc_cfg);
+ if (r < 0) {
+ nfc_err(dev, "NCI probing error\n");
+ return r;
+ }
+
+ dev_dbg(dev, "I2C driver loaded\n");
+ return 0;
+}
+
+static int fdp_nci_i2c_remove(struct i2c_client *client)
+{
+ struct fdp_i2c_phy *phy = i2c_get_clientdata(client);
+
+ dev_dbg(&client->dev, "%s\n", __func__);
+
+ fdp_nci_remove(phy->ndev);
+ fdp_nci_i2c_disable(phy);
+
+ return 0;
+}
+
+static struct i2c_device_id fdp_nci_i2c_id_table[] = {
+ {"int339a", 0},
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, fdp_nci_i2c_id_table);
+
+static const struct acpi_device_id fdp_nci_i2c_acpi_match[] = {
+ {"INT339A", 0},
+ {}
+};
+MODULE_DEVICE_TABLE(acpi, fdp_nci_i2c_acpi_match);
+
+static struct i2c_driver fdp_nci_i2c_driver = {
+ .driver = {
+ .name = FDP_I2C_DRIVER_NAME,
+ .acpi_match_table = ACPI_PTR(fdp_nci_i2c_acpi_match),
+ },
+ .id_table = fdp_nci_i2c_id_table,
+ .probe = fdp_nci_i2c_probe,
+ .remove = fdp_nci_i2c_remove,
+};
+module_i2c_driver(fdp_nci_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("I2C driver for Intel Fields Peak NFC controller");
+MODULE_AUTHOR("Robert Dolca <robert.dolca@intel.com>");
Code Review / kvmfornfv.git / blobdiff