1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Marvell NFC-over-SPI driver: SPI interface related functions 4 * 5 * Copyright (C) 2015, Marvell International Ltd. 6 */ 7 8 #include <linux/module.h> 9 #include <linux/interrupt.h> 10 #include <linux/nfc.h> 11 #include <linux/of_irq.h> 12 #include <net/nfc/nci.h> 13 #include <net/nfc/nci_core.h> 14 #include <linux/spi/spi.h> 15 #include "nfcmrvl.h" 16 17 #define SPI_WAIT_HANDSHAKE 1 18 19 struct nfcmrvl_spi_drv_data { 20 unsigned long flags; 21 struct spi_device *spi; 22 struct nci_spi *nci_spi; 23 struct completion handshake_completion; 24 struct nfcmrvl_private *priv; 25 }; 26 27 static irqreturn_t nfcmrvl_spi_int_irq_thread_fn(int irq, void *drv_data_ptr) 28 { 29 struct nfcmrvl_spi_drv_data *drv_data = drv_data_ptr; 30 struct sk_buff *skb; 31 32 /* 33 * Special case where we are waiting for SPI_INT deassertion to start a 34 * transfer. 35 */ 36 if (test_and_clear_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags)) { 37 complete(&drv_data->handshake_completion); 38 return IRQ_HANDLED; 39 } 40 41 /* Normal case, SPI_INT deasserted by slave to trigger a master read */ 42 43 skb = nci_spi_read(drv_data->nci_spi); 44 if (!skb) { 45 nfc_err(&drv_data->spi->dev, "failed to read spi packet"); 46 return IRQ_HANDLED; 47 } 48 49 if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0) 50 nfc_err(&drv_data->spi->dev, "corrupted RX packet"); 51 52 return IRQ_HANDLED; 53 } 54 55 static int nfcmrvl_spi_nci_open(struct nfcmrvl_private *priv) 56 { 57 return 0; 58 } 59 60 static int nfcmrvl_spi_nci_close(struct nfcmrvl_private *priv) 61 { 62 return 0; 63 } 64 65 static int nfcmrvl_spi_nci_send(struct nfcmrvl_private *priv, 66 struct sk_buff *skb) 67 { 68 struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data; 69 int err; 70 71 /* Reinit completion for slave handshake */ 72 reinit_completion(&drv_data->handshake_completion); 73 set_bit(SPI_WAIT_HANDSHAKE, &drv_data->flags); 74 75 /* 76 * Append a dummy byte at the end of SPI frame. This is due to a 77 * specific DMA implementation in the controller 78 */ 79 skb_put(skb, 1); 80 81 /* Send the SPI packet */ 82 err = nci_spi_send(drv_data->nci_spi, &drv_data->handshake_completion, 83 skb); 84 if (err) 85 nfc_err(priv->dev, "spi_send failed %d", err); 86 87 return err; 88 } 89 90 static void nfcmrvl_spi_nci_update_config(struct nfcmrvl_private *priv, 91 const void *param) 92 { 93 struct nfcmrvl_spi_drv_data *drv_data = priv->drv_data; 94 const struct nfcmrvl_fw_spi_config *config = param; 95 96 drv_data->nci_spi->xfer_speed_hz = config->clk; 97 } 98 99 static const struct nfcmrvl_if_ops spi_ops = { 100 .nci_open = nfcmrvl_spi_nci_open, 101 .nci_close = nfcmrvl_spi_nci_close, 102 .nci_send = nfcmrvl_spi_nci_send, 103 .nci_update_config = nfcmrvl_spi_nci_update_config, 104 }; 105 106 static int nfcmrvl_spi_parse_dt(struct device_node *node, 107 struct nfcmrvl_platform_data *pdata) 108 { 109 int ret; 110 111 ret = nfcmrvl_parse_dt(node, pdata); 112 if (ret < 0) { 113 pr_err("Failed to get generic entries\n"); 114 return ret; 115 } 116 117 ret = irq_of_parse_and_map(node, 0); 118 if (!ret) { 119 pr_err("Unable to get irq\n"); 120 return -EINVAL; 121 } 122 pdata->irq = ret; 123 124 return 0; 125 } 126 127 static int nfcmrvl_spi_probe(struct spi_device *spi) 128 { 129 const struct nfcmrvl_platform_data *pdata; 130 struct nfcmrvl_platform_data config; 131 struct nfcmrvl_spi_drv_data *drv_data; 132 int ret = 0; 133 134 drv_data = devm_kzalloc(&spi->dev, sizeof(*drv_data), GFP_KERNEL); 135 if (!drv_data) 136 return -ENOMEM; 137 138 drv_data->spi = spi; 139 drv_data->priv = NULL; 140 spi_set_drvdata(spi, drv_data); 141 142 pdata = spi->dev.platform_data; 143 144 if (!pdata && spi->dev.of_node) 145 if (nfcmrvl_spi_parse_dt(spi->dev.of_node, &config) == 0) 146 pdata = &config; 147 148 if (!pdata) 149 return -EINVAL; 150 151 ret = devm_request_threaded_irq(&drv_data->spi->dev, pdata->irq, 152 NULL, nfcmrvl_spi_int_irq_thread_fn, 153 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 154 "nfcmrvl_spi_int", drv_data); 155 if (ret < 0) { 156 nfc_err(&drv_data->spi->dev, "Unable to register IRQ handler"); 157 return -ENODEV; 158 } 159 160 drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_SPI, 161 drv_data, &spi_ops, 162 &drv_data->spi->dev, 163 pdata); 164 if (IS_ERR(drv_data->priv)) 165 return PTR_ERR(drv_data->priv); 166 167 drv_data->priv->support_fw_dnld = true; 168 169 drv_data->nci_spi = nci_spi_allocate_spi(drv_data->spi, 0, 10, 170 drv_data->priv->ndev); 171 172 /* Init completion for slave handshake */ 173 init_completion(&drv_data->handshake_completion); 174 return 0; 175 } 176 177 static void nfcmrvl_spi_remove(struct spi_device *spi) 178 { 179 struct nfcmrvl_spi_drv_data *drv_data = spi_get_drvdata(spi); 180 181 nfcmrvl_nci_unregister_dev(drv_data->priv); 182 } 183 184 static const struct of_device_id of_nfcmrvl_spi_match[] __maybe_unused = { 185 { .compatible = "marvell,nfc-spi", }, 186 {}, 187 }; 188 MODULE_DEVICE_TABLE(of, of_nfcmrvl_spi_match); 189 190 static const struct spi_device_id nfcmrvl_spi_id_table[] = { 191 { "nfcmrvl_spi", 0 }, 192 { } 193 }; 194 MODULE_DEVICE_TABLE(spi, nfcmrvl_spi_id_table); 195 196 static struct spi_driver nfcmrvl_spi_driver = { 197 .probe = nfcmrvl_spi_probe, 198 .remove = nfcmrvl_spi_remove, 199 .id_table = nfcmrvl_spi_id_table, 200 .driver = { 201 .name = "nfcmrvl_spi", 202 .owner = THIS_MODULE, 203 .of_match_table = of_match_ptr(of_nfcmrvl_spi_match), 204 }, 205 }; 206 207 module_spi_driver(nfcmrvl_spi_driver); 208 209 MODULE_AUTHOR("Marvell International Ltd."); 210 MODULE_DESCRIPTION("Marvell NFC-over-SPI driver"); 211 MODULE_LICENSE("GPL v2"); 212