/* ------------------------------------------------------------------------- * 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_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; *(u8 *)skb_push(skb, 1) = len & 0xff; *(u8 *)skb_push(skb, 1) = len >> 8; /* Compute and add lrc */ for (i = 0; i < len + 2; i++) lrc ^= skb->data[i]; skb_put_u8(skb, 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; } skb_put_data(*skb, 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_array(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 const struct acpi_gpio_params power_gpios = { 0, 0, false }; static const struct acpi_gpio_mapping acpi_fdp_gpios[] = { { "power-gpios", &power_gpios, 1 }, {}, }; static int fdp_nci_i2c_probe(struct i2c_client *client) { 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; } /* Checking if we have an irq */ if (client->irq <= 0) { nfc_err(dev, "IRQ not present\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); r = devm_request_threaded_irq(dev, 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; } r = devm_acpi_dev_add_driver_gpios(dev, acpi_fdp_gpios); if (r) dev_dbg(dev, "Unable to add GPIO mapping table\n"); /* Requesting the power gpio */ phy->power_gpio = devm_gpiod_get(dev, "power", 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 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), }, .probe_new = 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>");