| /* ------------------------------------------------------------------------- |
| * 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; |
| |
| if (!phy || irq != phy->i2c_dev->irq) { |
| WARN_ON_ONCE(1); |
| return IRQ_NONE; |
| } |
| |
| client = phy->i2c_dev; |
| dev_dbg(&client->dev, "%s\n", __func__); |
| |
| 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>"); |