diff options
Diffstat (limited to 'kernel/drivers/nfc/st21nfcb/i2c.c')
| -rw-r--r-- | kernel/drivers/nfc/st21nfcb/i2c.c | 388 |
1 files changed, 0 insertions, 388 deletions
diff --git a/kernel/drivers/nfc/st21nfcb/i2c.c b/kernel/drivers/nfc/st21nfcb/i2c.c deleted file mode 100644 index c44f8cf53..000000000 --- a/kernel/drivers/nfc/st21nfcb/i2c.c +++ /dev/null @@ -1,388 +0,0 @@ -/* - * I2C Link Layer for ST21NFCB NCI based Driver - * Copyright (C) 2014 STMicroelectronics SAS. All rights reserved. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms and conditions of the GNU General Public License, - * version 2, as published by the Free Software Foundation. - * - * 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. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, see <http://www.gnu.org/licenses/>. - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#include <linux/module.h> -#include <linux/i2c.h> -#include <linux/gpio.h> -#include <linux/of_irq.h> -#include <linux/of_gpio.h> -#include <linux/interrupt.h> -#include <linux/delay.h> -#include <linux/nfc.h> -#include <linux/platform_data/st21nfcb.h> - -#include "ndlc.h" - -#define DRIVER_DESC "NCI NFC driver for ST21NFCB" - -/* ndlc header */ -#define ST21NFCB_FRAME_HEADROOM 1 -#define ST21NFCB_FRAME_TAILROOM 0 - -#define ST21NFCB_NCI_I2C_MIN_SIZE 4 /* PCB(1) + NCI Packet header(3) */ -#define ST21NFCB_NCI_I2C_MAX_SIZE 250 /* req 4.2.1 */ - -#define ST21NFCB_NCI_I2C_DRIVER_NAME "st21nfcb_nci_i2c" - -static struct i2c_device_id st21nfcb_nci_i2c_id_table[] = { - {ST21NFCB_NCI_DRIVER_NAME, 0}, - {} -}; -MODULE_DEVICE_TABLE(i2c, st21nfcb_nci_i2c_id_table); - -struct st21nfcb_i2c_phy { - struct i2c_client *i2c_dev; - struct llt_ndlc *ndlc; - - unsigned int gpio_reset; - unsigned int irq_polarity; - - int powered; -}; - -#define I2C_DUMP_SKB(info, skb) \ -do { \ - pr_debug("%s:\n", info); \ - print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET, \ - 16, 1, (skb)->data, (skb)->len, 0); \ -} while (0) - -static int st21nfcb_nci_i2c_enable(void *phy_id) -{ - struct st21nfcb_i2c_phy *phy = phy_id; - - gpio_set_value(phy->gpio_reset, 0); - usleep_range(10000, 15000); - gpio_set_value(phy->gpio_reset, 1); - phy->powered = 1; - usleep_range(80000, 85000); - - return 0; -} - -static void st21nfcb_nci_i2c_disable(void *phy_id) -{ - struct st21nfcb_i2c_phy *phy = phy_id; - - phy->powered = 0; - /* reset chip in order to flush clf */ - gpio_set_value(phy->gpio_reset, 0); - usleep_range(10000, 15000); - gpio_set_value(phy->gpio_reset, 1); -} - -/* - * Writing a frame must not return the number of written bytes. - * It must return either zero for success, or <0 for error. - * In addition, it must not alter the skb - */ -static int st21nfcb_nci_i2c_write(void *phy_id, struct sk_buff *skb) -{ - int r = -1; - struct st21nfcb_i2c_phy *phy = phy_id; - struct i2c_client *client = phy->i2c_dev; - - I2C_DUMP_SKB("st21nfcb_nci_i2c_write", skb); - - if (phy->ndlc->hard_fault != 0) - return phy->ndlc->hard_fault; - - r = i2c_master_send(client, skb->data, skb->len); - if (r < 0) { /* Retry, chip was in standby */ - usleep_range(1000, 4000); - r = i2c_master_send(client, skb->data, skb->len); - } - - if (r >= 0) { - if (r != skb->len) - r = -EREMOTEIO; - else - r = 0; - } - - return r; -} - -/* - * Reads an ndlc frame and returns it in a newly allocated sk_buff. - * returns: - * frame size : if received frame is complete (find ST21NFCB_SOF_EOF at - * end of read) - * -EAGAIN : if received frame is incomplete (not find ST21NFCB_SOF_EOF - * at end of read) - * -EREMOTEIO : i2c read error (fatal) - * -EBADMSG : frame was incorrect and discarded - * (value returned from st21nfcb_nci_i2c_repack) - * -EIO : if no ST21NFCB_SOF_EOF is found after reaching - * the read length end sequence - */ -static int st21nfcb_nci_i2c_read(struct st21nfcb_i2c_phy *phy, - struct sk_buff **skb) -{ - int r; - u8 len; - u8 buf[ST21NFCB_NCI_I2C_MAX_SIZE]; - struct i2c_client *client = phy->i2c_dev; - - r = i2c_master_recv(client, buf, ST21NFCB_NCI_I2C_MIN_SIZE); - if (r < 0) { /* Retry, chip was in standby */ - usleep_range(1000, 4000); - r = i2c_master_recv(client, buf, ST21NFCB_NCI_I2C_MIN_SIZE); - } - - if (r != ST21NFCB_NCI_I2C_MIN_SIZE) - return -EREMOTEIO; - - len = be16_to_cpu(*(__be16 *) (buf + 2)); - if (len > ST21NFCB_NCI_I2C_MAX_SIZE) { - nfc_err(&client->dev, "invalid frame len\n"); - return -EBADMSG; - } - - *skb = alloc_skb(ST21NFCB_NCI_I2C_MIN_SIZE + len, GFP_KERNEL); - if (*skb == NULL) - return -ENOMEM; - - skb_reserve(*skb, ST21NFCB_NCI_I2C_MIN_SIZE); - skb_put(*skb, ST21NFCB_NCI_I2C_MIN_SIZE); - memcpy((*skb)->data, buf, ST21NFCB_NCI_I2C_MIN_SIZE); - - if (!len) - return 0; - - r = i2c_master_recv(client, buf, len); - if (r != len) { - kfree_skb(*skb); - return -EREMOTEIO; - } - - skb_put(*skb, len); - memcpy((*skb)->data + ST21NFCB_NCI_I2C_MIN_SIZE, buf, len); - - I2C_DUMP_SKB("i2c frame read", *skb); - - return 0; -} - -/* - * Reads an ndlc frame from the chip. - * - * On ST21NFCB, IRQ goes in idle state when read starts. - */ -static irqreturn_t st21nfcb_nci_irq_thread_fn(int irq, void *phy_id) -{ - struct st21nfcb_i2c_phy *phy = phy_id; - struct i2c_client *client; - struct sk_buff *skb = NULL; - int r; - - if (!phy || !phy->ndlc || irq != phy->i2c_dev->irq) { - WARN_ON_ONCE(1); - return IRQ_NONE; - } - - client = phy->i2c_dev; - dev_dbg(&client->dev, "IRQ\n"); - - if (phy->ndlc->hard_fault) - return IRQ_HANDLED; - - if (!phy->powered) { - st21nfcb_nci_i2c_disable(phy); - return IRQ_HANDLED; - } - - r = st21nfcb_nci_i2c_read(phy, &skb); - if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG) - return IRQ_HANDLED; - - ndlc_recv(phy->ndlc, skb); - - return IRQ_HANDLED; -} - -static struct nfc_phy_ops i2c_phy_ops = { - .write = st21nfcb_nci_i2c_write, - .enable = st21nfcb_nci_i2c_enable, - .disable = st21nfcb_nci_i2c_disable, -}; - -#ifdef CONFIG_OF -static int st21nfcb_nci_i2c_of_request_resources(struct i2c_client *client) -{ - struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client); - struct device_node *pp; - int gpio; - int r; - - pp = client->dev.of_node; - if (!pp) - return -ENODEV; - - /* Get GPIO from device tree */ - gpio = of_get_named_gpio(pp, "reset-gpios", 0); - if (gpio < 0) { - nfc_err(&client->dev, - "Failed to retrieve reset-gpios from device tree\n"); - return gpio; - } - - /* GPIO request and configuration */ - r = devm_gpio_request_one(&client->dev, gpio, - GPIOF_OUT_INIT_HIGH, "clf_reset"); - if (r) { - nfc_err(&client->dev, "Failed to request reset pin\n"); - return r; - } - phy->gpio_reset = gpio; - - phy->irq_polarity = irq_get_trigger_type(client->irq); - - return 0; -} -#else -static int st21nfcb_nci_i2c_of_request_resources(struct i2c_client *client) -{ - return -ENODEV; -} -#endif - -static int st21nfcb_nci_i2c_request_resources(struct i2c_client *client) -{ - struct st21nfcb_nfc_platform_data *pdata; - struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client); - int r; - - pdata = client->dev.platform_data; - if (pdata == NULL) { - nfc_err(&client->dev, "No platform data\n"); - return -EINVAL; - } - - /* store for later use */ - phy->gpio_reset = pdata->gpio_reset; - phy->irq_polarity = pdata->irq_polarity; - - r = devm_gpio_request_one(&client->dev, - phy->gpio_reset, GPIOF_OUT_INIT_HIGH, "clf_reset"); - if (r) { - pr_err("%s : reset gpio_request failed\n", __FILE__); - return r; - } - - return 0; -} - -static int st21nfcb_nci_i2c_probe(struct i2c_client *client, - const struct i2c_device_id *id) -{ - struct st21nfcb_i2c_phy *phy; - struct st21nfcb_nfc_platform_data *pdata; - int r; - - dev_dbg(&client->dev, "%s\n", __func__); - dev_dbg(&client->dev, "IRQ: %d\n", client->irq); - - if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { - nfc_err(&client->dev, "Need I2C_FUNC_I2C\n"); - return -ENODEV; - } - - phy = devm_kzalloc(&client->dev, sizeof(struct st21nfcb_i2c_phy), - GFP_KERNEL); - if (!phy) - return -ENOMEM; - - phy->i2c_dev = client; - - i2c_set_clientdata(client, phy); - - pdata = client->dev.platform_data; - if (!pdata && client->dev.of_node) { - r = st21nfcb_nci_i2c_of_request_resources(client); - if (r) { - nfc_err(&client->dev, "No platform data\n"); - return r; - } - } else if (pdata) { - r = st21nfcb_nci_i2c_request_resources(client); - if (r) { - nfc_err(&client->dev, - "Cannot get platform resources\n"); - return r; - } - } else { - nfc_err(&client->dev, - "st21nfcb platform resources not available\n"); - return -ENODEV; - } - - r = ndlc_probe(phy, &i2c_phy_ops, &client->dev, - ST21NFCB_FRAME_HEADROOM, ST21NFCB_FRAME_TAILROOM, - &phy->ndlc); - if (r < 0) { - nfc_err(&client->dev, "Unable to register ndlc layer\n"); - return r; - } - - r = devm_request_threaded_irq(&client->dev, client->irq, NULL, - st21nfcb_nci_irq_thread_fn, - phy->irq_polarity | IRQF_ONESHOT, - ST21NFCB_NCI_DRIVER_NAME, phy); - if (r < 0) - nfc_err(&client->dev, "Unable to register IRQ handler\n"); - - return r; -} - -static int st21nfcb_nci_i2c_remove(struct i2c_client *client) -{ - struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client); - - dev_dbg(&client->dev, "%s\n", __func__); - - ndlc_remove(phy->ndlc); - - return 0; -} - -#ifdef CONFIG_OF -static const struct of_device_id of_st21nfcb_i2c_match[] = { - { .compatible = "st,st21nfcb-i2c", }, - { .compatible = "st,st21nfcb_i2c", }, - {} -}; -MODULE_DEVICE_TABLE(of, of_st21nfcb_i2c_match); -#endif - -static struct i2c_driver st21nfcb_nci_i2c_driver = { - .driver = { - .owner = THIS_MODULE, - .name = ST21NFCB_NCI_I2C_DRIVER_NAME, - .of_match_table = of_match_ptr(of_st21nfcb_i2c_match), - }, - .probe = st21nfcb_nci_i2c_probe, - .id_table = st21nfcb_nci_i2c_id_table, - .remove = st21nfcb_nci_i2c_remove, -}; - -module_i2c_driver(st21nfcb_nci_i2c_driver); - -MODULE_LICENSE("GPL"); -MODULE_DESCRIPTION(DRIVER_DESC); |