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 int reset_n_io = -EINVAL;
  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_get_compatible_child(node, "marvell,nfc-uart");
  77         if (!matched_node) {
  78                 matched_node = of_get_compatible_child(node, "mrvl,nfc-uart");
  79                 if (!matched_node)
  80                         return -ENODEV;
  81         }
  82
  83         ret = nfcmrvl_parse_dt(matched_node, pdata);
  84         if (ret < 0) {
  85                 pr_err("Failed to get generic entries\n");
  86                 of_node_put(matched_node);
  87                 return ret;
  88         }
  89
  90         if (of_find_property(matched_node, "flow-control", NULL))
  91                 pdata->flow_control = 1;
  92         else
  93                 pdata->flow_control = 0;
  94
  95         if (of_find_property(matched_node, "break-control", NULL))
  96                 pdata->break_control = 1;
  97         else
  98                 pdata->break_control = 0;
  99
 100         of_node_put(matched_node);
 101
 102         return 0;
 103 }
 104
 105 /*
 106 ** NCI UART OPS
 107 */
 108
 109 static int nfcmrvl_nci_uart_open(struct nci_uart *nu)
 110 {
 111         struct nfcmrvl_private *priv;
 112         struct nfcmrvl_platform_data *pdata = NULL;
 113         struct nfcmrvl_platform_data config;
 114         struct device *dev = nu->tty->dev;
 115
 116         /*
 117          * Platform data cannot be used here since usually it is already used
 118          * by low level serial driver. We can try to retrieve serial device
 119          * and check if DT entries were added.
 120          */
 121
 122         if (dev && dev->parent && dev->parent->of_node)
 123                 if (nfcmrvl_uart_parse_dt(dev->parent->of_node, &config) == 0)
 124                         pdata = &config;
 125
 126         if (!pdata) {
 127                 pr_info("No platform data / DT -> fallback to module params\n");
 128                 config.hci_muxed = hci_muxed;
 129                 config.reset_n_io = reset_n_io;
 130                 config.flow_control = flow_control;
 131                 config.break_control = break_control;
 132                 pdata = &config;
 133         }
 134
 135         priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_UART, nu, &uart_ops,
 136                                         dev, pdata);
 137         if (IS_ERR(priv))
 138                 return PTR_ERR(priv);
 139
 140         priv->support_fw_dnld = true;
 141
 142         nu->drv_data = priv;
 143         nu->ndev = priv->ndev;
 144
 145         return 0;
 146 }
 147
 148 static void nfcmrvl_nci_uart_close(struct nci_uart *nu)
 149 {
 150         nfcmrvl_nci_unregister_dev((struct nfcmrvl_private *)nu->drv_data);
 151 }
 152
 153 static int nfcmrvl_nci_uart_recv(struct nci_uart *nu, struct sk_buff *skb)
 154 {
 155         return nfcmrvl_nci_recv_frame((struct nfcmrvl_private *)nu->drv_data,
 156                                       skb);
 157 }
 158
 159 static void nfcmrvl_nci_uart_tx_start(struct nci_uart *nu)
 160 {
 161         struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
 162
 163         if (priv->ndev->nfc_dev->fw_download_in_progress)
 164                 return;
 165
 166         /* Remove BREAK to wake up the NFCC */
 167         if (priv->config.break_control && nu->tty->ops->break_ctl) {
 168                 nu->tty->ops->break_ctl(nu->tty, 0);
 169                 usleep_range(3000, 5000);
 170         }
 171 }
 172
 173 static void nfcmrvl_nci_uart_tx_done(struct nci_uart *nu)
 174 {
 175         struct nfcmrvl_private *priv = (struct nfcmrvl_private *)nu->drv_data;
 176
 177         if (priv->ndev->nfc_dev->fw_download_in_progress)
 178                 return;
 179
 180         /*
 181         ** To ensure that if the NFCC goes in DEEP SLEEP sate we can wake him
 182         ** up. we set BREAK. Once we will be ready to send again we will remove
 183         ** it.
 184         */
 185         if (priv->config.break_control && nu->tty->ops->break_ctl) {
 186                 nu->tty->ops->break_ctl(nu->tty, -1);
 187                 usleep_range(1000, 3000);
 188         }
 189 }
 190
 191 static struct nci_uart nfcmrvl_nci_uart = {
 192         .owner  = THIS_MODULE,
 193         .name   = "nfcmrvl_uart",
 194         .driver = NCI_UART_DRIVER_MARVELL,
 195         .ops    = {
 196                 .open           = nfcmrvl_nci_uart_open,
 197                 .close          = nfcmrvl_nci_uart_close,
 198                 .recv           = nfcmrvl_nci_uart_recv,
 199                 .tx_start       = nfcmrvl_nci_uart_tx_start,
 200                 .tx_done        = nfcmrvl_nci_uart_tx_done,
 201         }
 202 };
 203
 204 /*
 205 ** Module init
 206 */
 207
 208 static int nfcmrvl_uart_init_module(void)
 209 {
 210         return nci_uart_register(&nfcmrvl_nci_uart);
 211 }
 212
 213 static void nfcmrvl_uart_exit_module(void)
 214 {
 215         nci_uart_unregister(&nfcmrvl_nci_uart);
 216 }
 217
 218 module_init(nfcmrvl_uart_init_module);
 219 module_exit(nfcmrvl_uart_exit_module);
 220
 221 MODULE_AUTHOR("Marvell International Ltd.");
 222 MODULE_DESCRIPTION("Marvell NFC-over-UART");
 223 MODULE_LICENSE("GPL v2");
 224
 225 module_param(flow_control, uint, 0);
 226 MODULE_PARM_DESC(flow_control, "Tell if UART needs flow control at init.");
 227
 228 module_param(break_control, uint, 0);
 229 MODULE_PARM_DESC(break_control, "Tell if UART driver must drive break signal.");
 230
 231 module_param(hci_muxed, uint, 0);
 232 MODULE_PARM_DESC(hci_muxed, "Tell if transport is muxed in HCI one.");
 233
 234 module_param(reset_n_io, int, 0);
 235 MODULE_PARM_DESC(reset_n_io, "GPIO that is wired to RESET_N signal.");