swh:1:snp:c2847dfd741eae21606027cf29250d1ebcd63fb4
Tip revision: 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d authored by Greg Kroah-Hartman on 22 October 2018, 06:37:37 UTC
Linux 4.19
Linux 4.19
Tip revision: 84df952
i2c.c
/* -------------------------------------------------------------------------
* 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>");