linux/drivers/nfc/nfcmrvl/uart.c

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/**
* Marvell NFC-over-UART driver
*
* Copyright (C) 2015, Marvell International Ltd.
*
* This software file (the "File") is distributed by Marvell International
* Ltd. under the terms of the GNU General Public License Version 2, June 1991
* (the "License"). You may use, redistribute and/or modify this File in
* accordance with the terms and conditions of the License, a copy of which
* is available on the worldwide web at
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
*
* THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
* IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
* ARE EXPRESSLY DISCLAIMED. The License provides additional details about
* this warranty disclaimer.
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/of_gpio.h>
#include <net/nfc/nci.h>
#include <net/nfc/nci_core.h>
#include "nfcmrvl.h"
static unsigned int hci_muxed;
static unsigned int flow_control;
static unsigned int break_control;
static unsigned int reset_n_io;
/*
** NFCMRVL NCI OPS
*/
static int nfcmrvl_uart_nci_open(struct nfcmrvl_private *priv)
{
return 0;
}
static int nfcmrvl_uart_nci_close(struct nfcmrvl_private *priv)
{
return 0;
}
static int nfcmrvl_uart_nci_send(struct nfcmrvl_private *priv,
struct sk_buff *skb)
{
struct nci_uart *nu = priv->drv_data;
return nu->ops.send(nu, skb);
}
static struct nfcmrvl_if_ops uart_ops = {
.nci_open = nfcmrvl_uart_nci_open,
.nci_close = nfcmrvl_uart_nci_close,
.nci_send = nfcmrvl_uart_nci_send,
};
#ifdef CONFIG_OF
static int nfcmrvl_uart_parse_dt(struct device_node *node,
struct nfcmrvl_platform_data *pdata)
{
struct device_node *matched_node;
int ret;
matched_node = of_find_compatible_node(node, NULL, "mrvl,nfc-uart");
if (!matched_node)
return -ENODEV;
ret = nfcmrvl_parse_dt(matched_node, pdata);
if (ret < 0) {
pr_err("Failed to get generic entries\n");
return ret;
}
if (of_find_property(matched_node, "flow-control", NULL))
pdata->flow_control = 1;
else
pdata->flow_control = 0;
if (of_find_property(matched_node, "break-control", NULL))
pdata->break_control = 1;
else
pdata->break_control = 0;
return 0;
}
#else
static int nfcmrvl_uart_parse_dt(struct device_node *node,
struct nfcmrvl_platform_data *pdata)
{
return -ENODEV;
}
#endif
/*
** NCI UART OPS
*/
static int nfcmrvl_nci_uart_open(struct nci_uart *nu)
{
struct nfcmrvl_private *priv;
struct nfcmrvl_platform_data *pdata = NULL;
struct nfcmrvl_platform_data config;
/*
* Platform data cannot be used here since usually it is already used
* by low level serial driver. We can try to retrieve serial device
* and check if DT entries were added.
*/
if (nu->tty->dev->parent && nu->tty->dev->parent->of_node)
if (nfcmrvl_uart_parse_dt(nu->tty->dev->parent->of_node,
&config) == 0)
pdata = &config;
if (!pdata) {
pr_info("No platform data / DT -> fallback to module params\n");
config.hci_muxed = hci_muxed;
config.reset_n_io = reset_n_io;
config.flow_control = flow_control;
config.break_control = break_control;
pdata = &config;
}
priv = nfcmrvl_nci_register_dev(nu, &uart_ops, nu->tty->dev, pdata);
if (IS_ERR(priv))
return PTR_ERR(priv);
priv->phy = NFCMRVL_PHY_UART;
nu->drv_data = priv;
nu->ndev = priv->ndev;
/* Set BREAK */
if (priv->config.break_control && nu->tty->ops->break_ctl)
nu->tty->ops->break_ctl(nu->tty, -1);
return 0;
}
static void nfcmrvl_nci_uart_close(struct nci_uart *nu)
{
nfcmrvl_nci_unregister_dev((struct nfcmrvl_private *)nu->drv_data);
}
static int nfcmrvl_nci_uart_recv(struct nci_uart *nu, struct sk_buff *skb)
{
return nfcmrvl_nci_recv_frame((struct nfcmrvl_private *)nu->drv_data,
skb);
}
static void nfcmrvl_nci_uart_tx_start(struct nci_uart *nu)
{
struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
/* Remove BREAK to wake up the NFCC */
if (priv->config.break_control && nu->tty->ops->break_ctl) {
nu->tty->ops->break_ctl(nu->tty, 0);
usleep_range(3000, 5000);
}
}
static void nfcmrvl_nci_uart_tx_done(struct nci_uart *nu)
{
struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
/*
** To ensure that if the NFCC goes in DEEP SLEEP sate we can wake him
** up. we set BREAK. Once we will be ready to send again we will remove
** it.
*/
if (priv->config.break_control && nu->tty->ops->break_ctl)
nu->tty->ops->break_ctl(nu->tty, -1);
}
static struct nci_uart nfcmrvl_nci_uart = {
.owner = THIS_MODULE,
.name = "nfcmrvl_uart",
.driver = NCI_UART_DRIVER_MARVELL,
.ops = {
.open = nfcmrvl_nci_uart_open,
.close = nfcmrvl_nci_uart_close,
.recv = nfcmrvl_nci_uart_recv,
.tx_start = nfcmrvl_nci_uart_tx_start,
.tx_done = nfcmrvl_nci_uart_tx_done,
}
};
/*
** Module init
*/
static int nfcmrvl_uart_init_module(void)
{
return nci_uart_register(&nfcmrvl_nci_uart);
}
static void nfcmrvl_uart_exit_module(void)
{
nci_uart_unregister(&nfcmrvl_nci_uart);
}
module_init(nfcmrvl_uart_init_module);
module_exit(nfcmrvl_uart_exit_module);
MODULE_AUTHOR("Marvell International Ltd.");
MODULE_DESCRIPTION("Marvell NFC-over-UART");
MODULE_LICENSE("GPL v2");
module_param(flow_control, uint, 0);
MODULE_PARM_DESC(flow_control, "Tell if UART needs flow control at init.");
module_param(break_control, uint, 0);
MODULE_PARM_DESC(break_control, "Tell if UART driver must drive break signal.");
module_param(hci_muxed, uint, 0);
MODULE_PARM_DESC(hci_muxed, "Tell if transport is muxed in HCI one.");
module_param(reset_n_io, uint, 0);
MODULE_PARM_DESC(reset_n_io, "GPIO that is wired to RESET_N signal.");