1 // SPDX-License-Identifier: GPL-2.0
3 // Register map access API - SPI AVMM support
5 // Copyright (C) 2018-2020 Intel Corporation. All rights reserved.
17  * The "SPI slave to Avalon Master Bridge" (spi-avmm) IP should be integrated
34  * Chapter "Avalon-ST Bytes to Packets and Packets to Bytes Converter Cores"
37  * Chapter "Avalon-ST Serial Peripheral Interface Core" describes the
47  * The spi-avmm IP on the slave chip decodes the byte stream and initiates
79  * it is proper that we limit 1KB xfer at max.
82 #define MAX_WRITE_CNT		1UL
144  * struct spi_avmm_bridge - SPI slave to AVMM bus master bridge
175  * Format transaction layer data in br->trans_buf according to the register
176  * access request, Store valid transaction layer data length in br->trans_len.
178 static int br_trans_tx_prepare(struct spi_avmm_bridge *br, bool is_read, u32 reg,  in br_trans_tx_prepare()  argument
188 		if (count == 1)  in br_trans_tx_prepare()
193 		if (count == 1)  in br_trans_tx_prepare()
199 	header = (struct trans_req_header *)br->trans_buf;  in br_trans_tx_prepare()
200 	header->code = code;  in br_trans_tx_prepare()
201 	header->rsvd = 0;  in br_trans_tx_prepare()
202 	header->size = cpu_to_be16((u16)count * SPI_AVMM_VAL_SIZE);  in br_trans_tx_prepare()
203 	header->addr = cpu_to_be32(reg);  in br_trans_tx_prepare()
209 		if (trans_len > sizeof(br->trans_buf))  in br_trans_tx_prepare()
210 			return -ENOMEM;  in br_trans_tx_prepare()
212 		data = (__le32 *)(br->trans_buf + TRANS_REQ_HD_SIZE);  in br_trans_tx_prepare()
219 	br->trans_len = trans_len;  in br_trans_tx_prepare()
225  * Convert transaction layer data (in br->trans_buf) to phy layer data, store
226  * them in br->phy_buf. Pad the phy_buf aligned with SPI's BPW. Store valid phy
227  * layer data length in br->phy_len.
237  * MOSI ...|7a|7c|00|10| |00|00|04|02| |4b|7d|5a|7b| |40|4a|4a|4a| |XX|XX|...
242  * before pad ...|7a|7c|00|10| |00|00|04|02| |4b|7d|5a|7b| |40|
243  * after pad  ...|7a|7c|00|10| |00|00|04|02| |4b|7d|5a|4a| |4a|4a|7b|40|
247 static int br_pkt_phy_tx_prepare(struct spi_avmm_bridge *br)  in br_pkt_phy_tx_prepare()  argument
253 	tb = br->trans_buf;  in br_pkt_phy_tx_prepare()
254 	tb_end = tb + br->trans_len;  in br_pkt_phy_tx_prepare()
255 	pb = br->phy_buf;  in br_pkt_phy_tx_prepare()
256 	pb_limit = pb + ARRAY_SIZE(br->phy_buf);  in br_pkt_phy_tx_prepare()
275 		if (tb == tb_end - 1 && !pb_eop) {  in br_pkt_phy_tx_prepare()
306 		return -ENOMEM;  in br_pkt_phy_tx_prepare()
309 	br->phy_len = pb - br->phy_buf;  in br_pkt_phy_tx_prepare()
311 	if (br->word_len == 1)  in br_pkt_phy_tx_prepare()
314 	/* Do phy buf padding if word_len > 1 byte. */  in br_pkt_phy_tx_prepare()
315 	aligned_phy_len = ALIGN(br->phy_len, br->word_len);  in br_pkt_phy_tx_prepare()
316 	if (aligned_phy_len > sizeof(br->phy_buf))  in br_pkt_phy_tx_prepare()
317 		return -ENOMEM;  in br_pkt_phy_tx_prepare()
319 	if (aligned_phy_len == br->phy_len)  in br_pkt_phy_tx_prepare()
323 	move_size = pb - pb_eop;  in br_pkt_phy_tx_prepare()
324 	memmove(&br->phy_buf[aligned_phy_len - move_size], pb_eop, move_size);  in br_pkt_phy_tx_prepare()
327 	memset(pb_eop, PHY_IDLE, aligned_phy_len - br->phy_len);  in br_pkt_phy_tx_prepare()
330 	br->phy_len = aligned_phy_len;  in br_pkt_phy_tx_prepare()
339 static int br_do_tx(struct spi_avmm_bridge *br)  in br_do_tx()  argument
342 	if (br->swap_words)  in br_do_tx()
343 		br->swap_words(br->phy_buf, br->phy_len);  in br_do_tx()
346 	return spi_write(br->spi, br->phy_buf, br->phy_len);  in br_do_tx()
351  * them to transaction layer data in br->trans_buf. It also stores the length
352  * of rx transaction layer data in br->trans_len
359 static int br_do_rx_and_pkt_phy_parse(struct spi_avmm_bridge *br)  in br_do_rx_and_pkt_phy_parse()  argument
363 	struct device *dev = &br->spi->dev;  in br_do_rx_and_pkt_phy_parse()
368 	tb_limit = br->trans_buf + ARRAY_SIZE(br->trans_buf);  in br_do_rx_and_pkt_phy_parse()
369 	pb = br->phy_buf;  in br_do_rx_and_pkt_phy_parse()
372 		ret = spi_read(br->spi, pb, br->word_len);  in br_do_rx_and_pkt_phy_parse()
377 		if (br->swap_words)  in br_do_rx_and_pkt_phy_parse()
378 			br->swap_words(pb, br->word_len);  in br_do_rx_and_pkt_phy_parse()
381 		for (i = 0; i < br->word_len; i++) {  in br_do_rx_and_pkt_phy_parse()
394 			 * a non-zero channel number is found.  in br_do_rx_and_pkt_phy_parse()
400 					return -EFAULT;  in br_do_rx_and_pkt_phy_parse()
412 				tb = br->trans_buf;  in br_do_rx_and_pkt_phy_parse()
426 					return -EFAULT;  in br_do_rx_and_pkt_phy_parse()
432 					return -EFAULT;  in br_do_rx_and_pkt_phy_parse()
439 					return -EFAULT;  in br_do_rx_and_pkt_phy_parse()
458 					br->trans_len = tb - br->trans_buf;  in br_do_rx_and_pkt_phy_parse()
479 				return -ETIMEDOUT;  in br_do_rx_and_pkt_phy_parse()
493 	return -EFAULT;  in br_do_rx_and_pkt_phy_parse()
500 static int br_rd_trans_rx_parse(struct spi_avmm_bridge *br,  in br_rd_trans_rx_parse()  argument
503 	unsigned int i, trans_len = br->trans_len;  in br_rd_trans_rx_parse()
507 		return -EFAULT;  in br_rd_trans_rx_parse()
509 	data = (__le32 *)br->trans_buf;  in br_rd_trans_rx_parse()
520 static int br_wr_trans_rx_parse(struct spi_avmm_bridge *br,  in br_wr_trans_rx_parse()  argument
523 	unsigned int trans_len = br->trans_len;  in br_wr_trans_rx_parse()
529 		return -EFAULT;  in br_wr_trans_rx_parse()
531 	resp = (struct trans_resp_header *)br->trans_buf;  in br_wr_trans_rx_parse()
533 	code = resp->r_code ^ 0x80;  in br_wr_trans_rx_parse()
534 	val_len = be16_to_cpu(resp->size);  in br_wr_trans_rx_parse()
536 		return -EFAULT;  in br_wr_trans_rx_parse()
541 		return -EFAULT;  in br_wr_trans_rx_parse()
549 	struct spi_avmm_bridge *br = context;  in do_reg_access()  local
553 	br->trans_len = 0;  in do_reg_access()
554 	br->phy_len = 0;  in do_reg_access()
556 	ret = br_trans_tx_prepare(br, is_read, reg, value, count);  in do_reg_access()
560 	ret = br_pkt_phy_tx_prepare(br);  in do_reg_access()
564 	ret = br_do_tx(br);  in do_reg_access()
568 	ret = br_do_rx_and_pkt_phy_parse(br);  in do_reg_access()
573 		return br_rd_trans_rx_parse(br, value, count);  in do_reg_access()
575 		return br_wr_trans_rx_parse(br, count);  in do_reg_access()
583 		return -EINVAL;  in regmap_spi_avmm_gather_write()
586 		return -EINVAL;  in regmap_spi_avmm_gather_write()
595 		return -EINVAL;  in regmap_spi_avmm_write()
599 					    bytes - SPI_AVMM_REG_SIZE);  in regmap_spi_avmm_write()
607 		return -EINVAL;  in regmap_spi_avmm_read()
610 		return -EINVAL;  in regmap_spi_avmm_read()
619 	struct spi_avmm_bridge *br;  in spi_avmm_bridge_ctx_gen()  local
622 		return ERR_PTR(-ENODEV);  in spi_avmm_bridge_ctx_gen()
625 	spi->mode = SPI_MODE_1;  in spi_avmm_bridge_ctx_gen()
626 	spi->bits_per_word = 32;  in spi_avmm_bridge_ctx_gen()
628 		spi->bits_per_word = 8;  in spi_avmm_bridge_ctx_gen()
630 			return ERR_PTR(-EINVAL);  in spi_avmm_bridge_ctx_gen()
633 	br = kzalloc(sizeof(*br), GFP_KERNEL);  in spi_avmm_bridge_ctx_gen()
634 	if (!br)  in spi_avmm_bridge_ctx_gen()
635 		return ERR_PTR(-ENOMEM);  in spi_avmm_bridge_ctx_gen()
637 	br->spi = spi;  in spi_avmm_bridge_ctx_gen()
638 	br->word_len = spi->bits_per_word / 8;  in spi_avmm_bridge_ctx_gen()
639 	if (br->word_len == 4) {  in spi_avmm_bridge_ctx_gen()
643 		 * if word length > 1.  in spi_avmm_bridge_ctx_gen()
645 		br->swap_words = br_swap_words_32;  in spi_avmm_bridge_ctx_gen()
648 	return br;  in spi_avmm_bridge_ctx_gen()
679 	map = __regmap_init(&spi->dev, &regmap_spi_avmm_bus,  in __regmap_init_spi_avmm()
702 	map = __devm_regmap_init(&spi->dev, &regmap_spi_avmm_bus,  in __devm_regmap_init_spi_avmm()
713 MODULE_DESCRIPTION("Register map access API - SPI AVMM support");