From b4b7ff4b08e691656c9d77c758fc355833128ac0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 20 Jan 2016 14:01:31 -0300 Subject: Linux-libre 4.4-gnu --- drivers/nfc/fdp/i2c.c | 388 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 388 insertions(+) create mode 100644 drivers/nfc/fdp/i2c.c (limited to 'drivers/nfc/fdp/i2c.c') diff --git a/drivers/nfc/fdp/i2c.c b/drivers/nfc/fdp/i2c.c new file mode 100644 index 000000000..532db2814 --- /dev/null +++ b/drivers/nfc/fdp/i2c.c @@ -0,0 +1,388 @@ +/* ------------------------------------------------------------------------- + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +#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 "); -- cgit v1.2.3-54-g00ecf