drivers/nfc/nfcmrvl/uart.c

   1 /**
   2  * Marvell NFC-over-UART driver
   3  *
   4  * Copyright (C) 2015, Marvell International Ltd.
   5  *
   6  * This software file (the "File") is distributed by Marvell International
   7  * Ltd. under the terms of the GNU General Public License Version 2, June 1991
   8  * (the "License").  You may use, redistribute and/or modify this File in
   9  * accordance with the terms and conditions of the License, a copy of which
  10  * is available on the worldwide web at
  11  * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
  12  *
  13  * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
  14  * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
  15  * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
  16  * this warranty disclaimer.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/delay.h>
  21 #include <linux/of_gpio.h>
  22 #include <net/nfc/nci.h>
  23 #include <net/nfc/nci_core.h>
  24 #include "nfcmrvl.h"
  25
  26 static unsigned int hci_muxed;
  27 static unsigned int flow_control;
  28 static unsigned int break_control;
  29 static unsigned int reset_n_io;
  30
  31 /*
  32 ** NFCMRVL NCI OPS
  33 */
  34
  35 static int nfcmrvl_uart_nci_open(struct nfcmrvl_private *priv)
  36 {
  37         return 0;
  38 }
  39
  40 static int nfcmrvl_uart_nci_close(struct nfcmrvl_private *priv)
  41 {
  42         return 0;
  43 }
  44
  45 static int nfcmrvl_uart_nci_send(struct nfcmrvl_private *priv,
  46                                  struct sk_buff *skb)
  47 {
  48         struct nci_uart *nu = priv->drv_data;
  49
  50         return nu->ops.send(nu, skb);
  51 }
  52
  53 static void nfcmrvl_uart_nci_update_config(struct nfcmrvl_private *priv,
  54                                            const void *param)
  55 {
  56         struct nci_uart *nu = priv->drv_data;
  57         const struct nfcmrvl_fw_uart_config *config = param;
  58
  59         nci_uart_set_config(nu, le32_to_cpu(config->baudrate),
  60                             config->flow_control);
  61 }
  62
  63 static struct nfcmrvl_if_ops uart_ops = {
  64         .nci_open = nfcmrvl_uart_nci_open,
  65         .nci_close = nfcmrvl_uart_nci_close,
  66         .nci_send = nfcmrvl_uart_nci_send,
  67         .nci_update_config = nfcmrvl_uart_nci_update_config
  68 };
  69
  70 static int nfcmrvl_uart_parse_dt(struct device_node *node,
  71                                  struct nfcmrvl_platform_data *pdata)
  72 {
  73         struct device_node *matched_node;
  74         int ret;
  75
  76         matched_node = of_find_compatible_node(node, NULL, "marvell,nfc-uart");
  77         if (!matched_node) {
  78                 matched_node = of_find_compatible_node(node, NULL,
  79                                                        "mrvl,nfc-uart");
  80                 if (!matched_node)
  81                         return -ENODEV;
  82         }
  83
  84         ret = nfcmrvl_parse_dt(matched_node, pdata);
  85         if (ret < 0) {
  86                 pr_err("Failed to get generic entries\n");
  87                 of_node_put(matched_node);
  88                 return ret;
  89         }
  90
  91         if (of_find_property(matched_node, "flow-control", NULL))
  92                 pdata->flow_control = 1;
  93         else
  94                 pdata->flow_control = 0;
  95
  96         if (of_find_property(matched_node, "break-control", NULL))
  97                 pdata->break_control = 1;
  98         else
  99                 pdata->break_control = 0;
 100
 101         of_node_put(matched_node);
 102
 103         return 0;
 104 }
 105
 106 /*
 107 ** NCI UART OPS
 108 */
 109
 110 static int nfcmrvl_nci_uart_open(struct nci_uart *nu)
 111 {
 112         struct nfcmrvl_private *priv;
 113         struct nfcmrvl_platform_data *pdata = NULL;
 114         struct nfcmrvl_platform_data config;
 115         struct device *dev = nu->tty->dev;
 116
 117         /*
 118          * Platform data cannot be used here since usually it is already used
 119          * by low level serial driver. We can try to retrieve serial device
 120          * and check if DT entries were added.
 121          */
 122
 123         if (dev && dev->parent && dev->parent->of_node)
 124                 if (nfcmrvl_uart_parse_dt(dev->parent->of_node, &config) == 0)
 125                         pdata = &config;
 126
 127         if (!pdata) {
 128                 pr_info("No platform data / DT -> fallback to module params\n");
 129                 config.hci_muxed = hci_muxed;
 130                 config.reset_n_io = reset_n_io;
 131                 config.flow_control = flow_control;
 132                 config.break_control = break_control;
 133                 pdata = &config;
 134         }
 135
 136         priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_UART, nu, &uart_ops,
 137                                         dev, pdata);
 138         if (IS_ERR(priv))
 139                 return PTR_ERR(priv);
 140
 141         priv->support_fw_dnld = true;
 142
 143         nu->drv_data = priv;
 144         nu->ndev = priv->ndev;
 145
 146         return 0;
 147 }
 148
 149 static void nfcmrvl_nci_uart_close(struct nci_uart *nu)
 150 {
 151         nfcmrvl_nci_unregister_dev((struct nfcmrvl_private *)nu->drv_data);
 152 }
 153
 154 static int nfcmrvl_nci_uart_recv(struct nci_uart *nu, struct sk_buff *skb)
 155 {
 156         return nfcmrvl_nci_recv_frame((struct nfcmrvl_private *)nu->drv_data,
 157                                       skb);
 158 }
 159
 160 static void nfcmrvl_nci_uart_tx_start(struct nci_uart *nu)
 161 {
 162         struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
 163
 164         if (priv->ndev->nfc_dev->fw_download_in_progress)
 165                 return;
 166
 167         /* Remove BREAK to wake up the NFCC */
 168         if (priv->config.break_control && nu->tty->ops->break_ctl) {
 169                 nu->tty->ops->break_ctl(nu->tty, 0);
 170                 usleep_range(3000, 5000);
 171         }
 172 }
 173
 174 static void nfcmrvl_nci_uart_tx_done(struct nci_uart *nu)
 175 {
 176         struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
 177
 178         if (priv->ndev->nfc_dev->fw_download_in_progress)
 179                 return;
 180
 181         /*
 182         ** To ensure that if the NFCC goes in DEEP SLEEP sate we can wake him
 183         ** up. we set BREAK. Once we will be ready to send again we will remove
 184         ** it.
 185         */
 186         if (priv->config.break_control && nu->tty->ops->break_ctl) {
 187                 nu->tty->ops->break_ctl(nu->tty, -1);
 188                 usleep_range(1000, 3000);
 189         }
 190 }
 191
 192 static struct nci_uart nfcmrvl_nci_uart = {
 193         .owner  = THIS_MODULE,
 194         .name   = "nfcmrvl_uart",
 195         .driver = NCI_UART_DRIVER_MARVELL,
 196         .ops    = {
 197                 .open           = nfcmrvl_nci_uart_open,
 198                 .close          = nfcmrvl_nci_uart_close,
 199                 .recv           = nfcmrvl_nci_uart_recv,
 200                 .tx_start       = nfcmrvl_nci_uart_tx_start,
 201                 .tx_done        = nfcmrvl_nci_uart_tx_done,
 202         }
 203 };
 204
 205 /*
 206 ** Module init
 207 */
 208
 209 static int nfcmrvl_uart_init_module(void)
 210 {
 211         return nci_uart_register(&nfcmrvl_nci_uart);
 212 }
 213
 214 static void nfcmrvl_uart_exit_module(void)
 215 {
 216         nci_uart_unregister(&nfcmrvl_nci_uart);
 217 }
 218
 219 module_init(nfcmrvl_uart_init_module);
 220 module_exit(nfcmrvl_uart_exit_module);
 221
 222 MODULE_AUTHOR("Marvell International Ltd.");
 223 MODULE_DESCRIPTION("Marvell NFC-over-UART");
 224 MODULE_LICENSE("GPL v2");
 225
 226 module_param(flow_control, uint, 0);
 227 MODULE_PARM_DESC(flow_control, "Tell if UART needs flow control at init.");
 228
 229 module_param(break_control, uint, 0);
 230 MODULE_PARM_DESC(break_control, "Tell if UART driver must drive break signal.");
 231
 232 module_param(hci_muxed, uint, 0);
 233 MODULE_PARM_DESC(hci_muxed, "Tell if transport is muxed in HCI one.");
 234
 235 module_param(reset_n_io, uint, 0);
 236 MODULE_PARM_DESC(reset_n_io, "GPIO that is wired to RESET_N signal.");