1 // SPDX-License-Identifier: GPL-2.0-only
11 #include <linux/spi/spi.h>
12 #include <linux/crc-ccitt.h>
37 	/* a NULL skb means we just want the SPI chip select line to raise */  in __nci_spi_send()
39 		t.tx_buf = skb->data;  in __nci_spi_send()
40 		t.len = skb->len;  in __nci_spi_send()
47 	t.delay_usecs = nspi->xfer_udelay;  in __nci_spi_send()
48 	t.speed_hz = nspi->xfer_speed_hz;  in __nci_spi_send()
53 	return spi_sync(nspi->spi, &m);  in __nci_spi_send()
60 	unsigned int payload_len = skb->len;  in nci_spi_send()
65 	/* add the NCI SPI header to the start of the buffer */  in nci_spi_send()
68 	hdr[1] = nspi->acknowledge_mode;  in nci_spi_send()
72 	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {  in nci_spi_send()
75 		crc = crc_ccitt(CRC_INIT, skb->data, skb->len);  in nci_spi_send()
81 		/* Trick SPI driver to raise chip select */  in nci_spi_send()
89 			ret = -ETIME;  in nci_spi_send()
95 	if (ret != 0 || nspi->acknowledge_mode == NCI_SPI_CRC_DISABLED)  in nci_spi_send()
98 	reinit_completion(&nspi->req_completion);  in nci_spi_send()
100 							&nspi->req_completion,  in nci_spi_send()
103 	if (completion_rc <= 0 || nspi->req_result == ACKNOWLEDGE_NACK)  in nci_spi_send()
104 		ret = -EIO;  in nci_spi_send()
113 /* ---- Interface to NCI SPI drivers ---- */
116  * nci_spi_allocate_spi - allocate a new nci spi
118  * @spi: SPI device
120  * @delay: delay between transactions in us
123 struct nci_spi *nci_spi_allocate_spi(struct spi_device *spi,  in nci_spi_allocate_spi()  argument
124 				     u8 acknowledge_mode, unsigned int delay,  in nci_spi_allocate_spi()  argument
129 	nspi = devm_kzalloc(&spi->dev, sizeof(struct nci_spi), GFP_KERNEL);  in nci_spi_allocate_spi()
133 	nspi->acknowledge_mode = acknowledge_mode;  in nci_spi_allocate_spi()
134 	nspi->xfer_udelay = delay;  in nci_spi_allocate_spi()
135 	/* Use controller max SPI speed by default */  in nci_spi_allocate_spi()
136 	nspi->xfer_speed_hz = 0;  in nci_spi_allocate_spi()
137 	nspi->spi = spi;  in nci_spi_allocate_spi()
138 	nspi->ndev = ndev;  in nci_spi_allocate_spi()
139 	init_completion(&nspi->req_completion);  in nci_spi_allocate_spi()
152 	skb = nci_skb_alloc(nspi->ndev, 0, GFP_KERNEL);  in send_acknowledge()
154 	/* add the NCI SPI header to the start of the buffer */  in send_acknowledge()
161 	crc = crc_ccitt(CRC_INIT, skb->data, skb->len);  in send_acknowledge()
177 	struct spi_transfer tx, rx;  in __nci_spi_read()  local
183 	memset(&tx, 0, sizeof(struct spi_transfer));  in __nci_spi_read()
185 	req[1] = nspi->acknowledge_mode;  in __nci_spi_read()
186 	tx.tx_buf = req;  in __nci_spi_read()
187 	tx.len = 2;  in __nci_spi_read()
188 	tx.cs_change = 0;  in __nci_spi_read()
189 	tx.speed_hz = nspi->xfer_speed_hz;  in __nci_spi_read()
190 	spi_message_add_tail(&tx, &m);  in __nci_spi_read()
196 	rx.speed_hz = nspi->xfer_speed_hz;  in __nci_spi_read()
199 	ret = spi_sync(nspi->spi, &m);  in __nci_spi_read()
203 	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED)  in __nci_spi_read()
209 	skb = nci_skb_alloc(nspi->ndev, rx_len, GFP_KERNEL);  in __nci_spi_read()
219 	rx.delay_usecs = nspi->xfer_udelay;  in __nci_spi_read()
220 	rx.speed_hz = nspi->xfer_speed_hz;  in __nci_spi_read()
223 	ret = spi_sync(nspi->spi, &m);  in __nci_spi_read()
227 	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {  in __nci_spi_read()
242 	u16 crc_data = (skb->data[skb->len - 2] << 8) |  in nci_spi_check_crc()
243 			skb->data[skb->len - 1];  in nci_spi_check_crc()
246 	ret = (crc_ccitt(CRC_INIT, skb->data, skb->len - NCI_SPI_CRC_LEN)  in nci_spi_check_crc()
249 	skb_trim(skb, skb->len - NCI_SPI_CRC_LEN);  in nci_spi_check_crc()
258 	ret = skb->data[0] >> NCI_SPI_ACK_SHIFT;  in nci_spi_get_ack()
267  * nci_spi_read - read frame from NCI SPI drivers
269  * @nspi: The nci spi
273  * is non-interruptible, and has no timeout.
281 	/* Retrieve frame from SPI */  in nci_spi_read()
286 	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {  in nci_spi_read()
295 		nspi->req_result = nci_spi_get_ack(skb);  in nci_spi_read()
296 		if (nspi->req_result)  in nci_spi_read()
297 			complete(&nspi->req_completion);  in nci_spi_read()
303 	if (!skb->len) {  in nci_spi_read()
309 	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED)  in nci_spi_read()