1 // SPDX-License-Identifier: GPL-2.0-only
3  * SPI-Engine SPI controller driver
5  *  Author: Lars-Peter Clausen <lars@metafoo.de>
9 #include <linux/fpga/adi-axi-common.h>
16 #include <linux/spi/spi.h>
78  * struct spi_engine_message_state - SPI engine per-message state
109 	void __iomem *base;  member
122 		p->instructions[p->length] = cmd;  in spi_engine_program_add_cmd()
123 	p->length++;  in spi_engine_program_add_cmd()
126 static unsigned int spi_engine_get_config(struct spi_device *spi)  in spi_engine_get_config()  argument
130 	if (spi->mode & SPI_CPOL)  in spi_engine_get_config()
132 	if (spi->mode & SPI_CPHA)  in spi_engine_get_config()
134 	if (spi->mode & SPI_3WIRE)  in spi_engine_get_config()
141 	struct spi_device *spi, struct spi_transfer *xfer)  in spi_engine_get_clk_div()  argument
145 	clk_div = DIV_ROUND_UP(clk_get_rate(spi_engine->ref_clk),  in spi_engine_get_clk_div()
146 		xfer->speed_hz * 2);  in spi_engine_get_clk_div()
150 		clk_div -= 1;  in spi_engine_get_clk_div()
158 	unsigned int len = xfer->len;  in spi_engine_gen_xfer()
164 		if (xfer->tx_buf)  in spi_engine_gen_xfer()
166 		if (xfer->rx_buf)  in spi_engine_gen_xfer()
170 			SPI_ENGINE_CMD_TRANSFER(flags, n - 1));  in spi_engine_gen_xfer()
171 		len -= n;  in spi_engine_gen_xfer()
179 	unsigned int spi_clk = clk_get_rate(spi_engine->ref_clk);  in spi_engine_gen_sleep()
183 	delay = spi_delay_to_ns(&xfer->delay, xfer);  in spi_engine_gen_sleep()
195 		spi_engine_program_add_cmd(p, dry, SPI_ENGINE_CMD_SLEEP(n - 1));  in spi_engine_gen_sleep()
196 		t -= n;  in spi_engine_gen_sleep()
201 		struct spi_device *spi, bool assert)  in spi_engine_gen_cs()  argument
206 		mask ^= BIT(spi_get_chipselect(spi, 0));  in spi_engine_gen_cs()
214 	struct spi_device *spi = msg->spi;  in spi_engine_compile_message()  local
219 	clk_div = -1;  in spi_engine_compile_message()
223 			spi_engine_get_config(spi)));  in spi_engine_compile_message()
225 	list_for_each_entry(xfer, &msg->transfers, transfer_list) {  in spi_engine_compile_message()
226 		new_clk_div = spi_engine_get_clk_div(spi_engine, spi, xfer);  in spi_engine_compile_message()
235 			spi_engine_gen_cs(p, dry, spi, true);  in spi_engine_compile_message()
240 		cs_change = xfer->cs_change;  in spi_engine_compile_message()
241 		if (list_is_last(&xfer->transfer_list, &msg->transfers))  in spi_engine_compile_message()
245 			spi_engine_gen_cs(p, dry, spi, false);  in spi_engine_compile_message()
254 	struct spi_message *msg = spi_engine->msg;  in spi_engine_xfer_next()
258 		xfer = list_first_entry(&msg->transfers,  in spi_engine_xfer_next()
260 	} else if (list_is_last(&xfer->transfer_list, &msg->transfers)) {  in spi_engine_xfer_next()
271 	struct spi_engine_message_state *st = spi_engine->msg->state;  in spi_engine_tx_next()
272 	struct spi_transfer *xfer = st->tx_xfer;  in spi_engine_tx_next()
276 	} while (xfer && !xfer->tx_buf);  in spi_engine_tx_next()
278 	st->tx_xfer = xfer;  in spi_engine_tx_next()
280 		st->tx_length = xfer->len;  in spi_engine_tx_next()
281 		st->tx_buf = xfer->tx_buf;  in spi_engine_tx_next()
283 		st->tx_buf = NULL;  in spi_engine_tx_next()
289 	struct spi_engine_message_state *st = spi_engine->msg->state;  in spi_engine_rx_next()
290 	struct spi_transfer *xfer = st->rx_xfer;  in spi_engine_rx_next()
294 	} while (xfer && !xfer->rx_buf);  in spi_engine_rx_next()
296 	st->rx_xfer = xfer;  in spi_engine_rx_next()
298 		st->rx_length = xfer->len;  in spi_engine_rx_next()
299 		st->rx_buf = xfer->rx_buf;  in spi_engine_rx_next()
301 		st->rx_buf = NULL;  in spi_engine_rx_next()
307 	void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_CMD_FIFO;  in spi_engine_write_cmd_fifo()
308 	struct spi_engine_message_state *st = spi_engine->msg->state;  in spi_engine_write_cmd_fifo()
312 	n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_CMD_FIFO_ROOM);  in spi_engine_write_cmd_fifo()
313 	while (n && st->cmd_length) {  in spi_engine_write_cmd_fifo()
314 		m = min(n, st->cmd_length);  in spi_engine_write_cmd_fifo()
315 		buf = st->cmd_buf;  in spi_engine_write_cmd_fifo()
318 		st->cmd_buf += m;  in spi_engine_write_cmd_fifo()
319 		st->cmd_length -= m;  in spi_engine_write_cmd_fifo()
320 		n -= m;  in spi_engine_write_cmd_fifo()
323 	return st->cmd_length != 0;  in spi_engine_write_cmd_fifo()
328 	void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDO_DATA_FIFO;  in spi_engine_write_tx_fifo()
329 	struct spi_engine_message_state *st = spi_engine->msg->state;  in spi_engine_write_tx_fifo()
333 	n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDO_FIFO_ROOM);  in spi_engine_write_tx_fifo()
334 	while (n && st->tx_length) {  in spi_engine_write_tx_fifo()
335 		m = min(n, st->tx_length);  in spi_engine_write_tx_fifo()
336 		buf = st->tx_buf;  in spi_engine_write_tx_fifo()
339 		st->tx_buf += m;  in spi_engine_write_tx_fifo()
340 		st->tx_length -= m;  in spi_engine_write_tx_fifo()
341 		n -= m;  in spi_engine_write_tx_fifo()
342 		if (st->tx_length == 0)  in spi_engine_write_tx_fifo()
346 	return st->tx_length != 0;  in spi_engine_write_tx_fifo()
351 	void __iomem *addr = spi_engine->base + SPI_ENGINE_REG_SDI_DATA_FIFO;  in spi_engine_read_rx_fifo()
352 	struct spi_engine_message_state *st = spi_engine->msg->state;  in spi_engine_read_rx_fifo()
356 	n = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_SDI_FIFO_LEVEL);  in spi_engine_read_rx_fifo()
357 	while (n && st->rx_length) {  in spi_engine_read_rx_fifo()
358 		m = min(n, st->rx_length);  in spi_engine_read_rx_fifo()
359 		buf = st->rx_buf;  in spi_engine_read_rx_fifo()
362 		st->rx_buf += m;  in spi_engine_read_rx_fifo()
363 		st->rx_length -= m;  in spi_engine_read_rx_fifo()
364 		n -= m;  in spi_engine_read_rx_fifo()
365 		if (st->rx_length == 0)  in spi_engine_read_rx_fifo()
369 	return st->rx_length != 0;  in spi_engine_read_rx_fifo()
379 	pending = readl_relaxed(spi_engine->base + SPI_ENGINE_REG_INT_PENDING);  in spi_engine_irq()
383 			spi_engine->base + SPI_ENGINE_REG_INT_PENDING);  in spi_engine_irq()
384 		spi_engine->completed_id = readl_relaxed(  in spi_engine_irq()
385 			spi_engine->base + SPI_ENGINE_REG_SYNC_ID);  in spi_engine_irq()
388 	spin_lock(&spi_engine->lock);  in spi_engine_irq()
405 	if (pending & SPI_ENGINE_INT_SYNC && spi_engine->msg) {  in spi_engine_irq()
406 		struct spi_engine_message_state *st = spi_engine->msg->state;  in spi_engine_irq()
408 		if (spi_engine->completed_id == st->sync_id) {  in spi_engine_irq()
409 			struct spi_message *msg = spi_engine->msg;  in spi_engine_irq()
410 			struct spi_engine_message_state *st = msg->state;  in spi_engine_irq()
412 			ida_free(&spi_engine->sync_ida, st->sync_id);  in spi_engine_irq()
413 			kfree(st->p);  in spi_engine_irq()
415 			msg->status = 0;  in spi_engine_irq()
416 			msg->actual_length = msg->frame_length;  in spi_engine_irq()
417 			spi_engine->msg = NULL;  in spi_engine_irq()
424 		spi_engine->int_enable &= ~disable_int;  in spi_engine_irq()
425 		writel_relaxed(spi_engine->int_enable,  in spi_engine_irq()
426 			spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);  in spi_engine_irq()
429 	spin_unlock(&spi_engine->lock);  in spi_engine_irq()
447 		return -ENOMEM;  in spi_engine_transfer_one_message()
452 	size = sizeof(*p->instructions) * (p_dry.length + 1);  in spi_engine_transfer_one_message()
456 		return -ENOMEM;  in spi_engine_transfer_one_message()
459 	ret = ida_alloc_range(&spi_engine->sync_ida, 0, U8_MAX, GFP_KERNEL);  in spi_engine_transfer_one_message()
466 	st->sync_id = ret;  in spi_engine_transfer_one_message()
470 	spin_lock_irqsave(&spi_engine->lock, flags);  in spi_engine_transfer_one_message()
471 	spi_engine_program_add_cmd(p, false, SPI_ENGINE_CMD_SYNC(st->sync_id));  in spi_engine_transfer_one_message()
473 	msg->state = st;  in spi_engine_transfer_one_message()
474 	spi_engine->msg = msg;  in spi_engine_transfer_one_message()
475 	st->p = p;  in spi_engine_transfer_one_message()
477 	st->cmd_buf = p->instructions;  in spi_engine_transfer_one_message()
478 	st->cmd_length = p->length;  in spi_engine_transfer_one_message()
487 	if (st->rx_length != 0)  in spi_engine_transfer_one_message()
493 		spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);  in spi_engine_transfer_one_message()
494 	spi_engine->int_enable = int_enable;  in spi_engine_transfer_one_message()
495 	spin_unlock_irqrestore(&spi_engine->lock, flags);  in spi_engine_transfer_one_message()
512 	host = devm_spi_alloc_host(&pdev->dev, sizeof(*spi_engine));  in spi_engine_probe()
514 		return -ENOMEM;  in spi_engine_probe()
518 	spin_lock_init(&spi_engine->lock);  in spi_engine_probe()
519 	ida_init(&spi_engine->sync_ida);  in spi_engine_probe()
521 	spi_engine->clk = devm_clk_get_enabled(&pdev->dev, "s_axi_aclk");  in spi_engine_probe()
522 	if (IS_ERR(spi_engine->clk))  in spi_engine_probe()
523 		return PTR_ERR(spi_engine->clk);  in spi_engine_probe()
525 	spi_engine->ref_clk = devm_clk_get_enabled(&pdev->dev, "spi_clk");  in spi_engine_probe()
526 	if (IS_ERR(spi_engine->ref_clk))  in spi_engine_probe()
527 		return PTR_ERR(spi_engine->ref_clk);  in spi_engine_probe()
529 	spi_engine->base = devm_platform_ioremap_resource(pdev, 0);  in spi_engine_probe()
530 	if (IS_ERR(spi_engine->base))  in spi_engine_probe()
531 		return PTR_ERR(spi_engine->base);  in spi_engine_probe()
533 	version = readl(spi_engine->base + ADI_AXI_REG_VERSION);  in spi_engine_probe()
535 		dev_err(&pdev->dev, "Unsupported peripheral version %u.%u.%u\n",  in spi_engine_probe()
539 		return -ENODEV;  in spi_engine_probe()
542 	writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_RESET);  in spi_engine_probe()
543 	writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);  in spi_engine_probe()
544 	writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);  in spi_engine_probe()
546 	ret = request_irq(irq, spi_engine_irq, 0, pdev->name, host);  in spi_engine_probe()
550 	host->dev.of_node = pdev->dev.of_node;  in spi_engine_probe()
551 	host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_3WIRE;  in spi_engine_probe()
552 	host->bits_per_word_mask = SPI_BPW_MASK(8);  in spi_engine_probe()
553 	host->max_speed_hz = clk_get_rate(spi_engine->ref_clk) / 2;  in spi_engine_probe()
554 	host->transfer_one_message = spi_engine_transfer_one_message;  in spi_engine_probe()
555 	host->num_chipselect = 8;  in spi_engine_probe()
579 	writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);  in spi_engine_remove()
580 	writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);  in spi_engine_remove()
581 	writel_relaxed(0x01, spi_engine->base + SPI_ENGINE_REG_RESET);  in spi_engine_remove()
585 	{ .compatible = "adi,axi-spi-engine-1.00.a" },
594 		.name = "spi-engine",
600 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
601 MODULE_DESCRIPTION("Analog Devices SPI engine peripheral driver");