1 // SPDX-License-Identifier: GPL-2.0
7 // Based on spi-sifive.c, Copyright 2018 SiFive, Inc.
114  * intra-word delay is 0xffff refclocks. So the maximum time a transfer
117  * (0x7ff * 32 + 0xffff) * 16 / 24e6 Hz ~= 87ms
119  * Double it and round it up to 200ms for good measure.
126 	struct completion done;         /* wake-up from interrupt */
131 	writel_relaxed(value, spi->regs + offset);  in reg_write()
136 	return readl_relaxed(spi->regs + offset);  in reg_read()
150 	/* Set CS high (inactive) and disable override and auto-CS */  in apple_spi_init()
176 	struct spi_device *device = msg->spi;  in apple_spi_prepare_message()
178 	u32 cfg = ((device->mode & SPI_CPHA ? APPLE_SPI_CFG_CPHA : 0) |  in apple_spi_prepare_message()
179 		   (device->mode & SPI_CPOL ? APPLE_SPI_CFG_CPOL : 0) |  in apple_spi_prepare_message()
180 		   (device->mode & SPI_LSB_FIRST ? APPLE_SPI_CFG_LSB_FIRST : 0));  in apple_spi_prepare_message()
191 	struct apple_spi *spi = spi_controller_get_devdata(device->controller);  in apple_spi_set_cs()
201 	cr = DIV_ROUND_UP(clk_get_rate(spi->clk), t->speed_hz);  in apple_spi_prep_transfer()
206 		 FIELD_PREP(APPLE_SPI_SHIFTCFG_BITS, t->bits_per_word));  in apple_spi_prep_transfer()
208 	/* We will want to poll if the time we need to wait is  in apple_spi_prep_transfer()
211 	 *    bits_per_word * fifo_threshold / hz <= 5 * 10^-6  in apple_spi_prep_transfer()
215 	return (200000 * t->bits_per_word * fifo_threshold) <= t->speed_hz;  in apple_spi_prep_transfer()
228 		complete(&spi->done);  in apple_spi_irq()
235 static int apple_spi_wait(struct apple_spi *spi, u32 fifo_bit, u32 xfer_bit, int poll)  in apple_spi_wait()  argument
239 	if (poll) {  in apple_spi_wait()
241 		unsigned long timeout = jiffies + APPLE_SPI_TIMEOUT_MS * HZ / 1000;  in apple_spi_wait()  local
246 			if (time_after(jiffies, timeout)) {  in apple_spi_wait()
247 				ret = -ETIMEDOUT;  in apple_spi_wait()
252 		reinit_completion(&spi->done);  in apple_spi_wait()
256 		if (!wait_for_completion_timeout(&spi->done,  in apple_spi_wait()
258 			ret = -ETIMEDOUT;  in apple_spi_wait()
276 	words = wrote = min_t(u32, *left, APPLE_SPI_FIFO_DEPTH - inuse);  in apple_spi_tx()
281 	*left -= words;  in apple_spi_tx()
287 		while (words--)  in apple_spi_tx()
294 		while (words--)  in apple_spi_tx()
301 		while (words--)  in apple_spi_tx()
326 	*left -= min_t(u32, *left, words);  in apple_spi_rx()
332 		while (words--)  in apple_spi_rx()
339 		while (words--)  in apple_spi_rx()
346 		while (words--)  in apple_spi_rx()
361 	bool poll = apple_spi_prep_transfer(spi, t);  in apple_spi_transfer_one()  local
362 	const void *tx_ptr = t->tx_buf;  in apple_spi_transfer_one()
363 	void *rx_ptr = t->rx_buf;  in apple_spi_transfer_one()
371 	if (t->bits_per_word > 16)  in apple_spi_transfer_one()
373 	else if (t->bits_per_word > 8)  in apple_spi_transfer_one()
378 	words = t->len / bytes_per_word;  in apple_spi_transfer_one()
417 		ret = apple_spi_wait(spi, fifo_flags, xfer_flags, poll);  in apple_spi_transfer_one()
419 			dev_err(&ctlr->dev, "transfer timed out (remaining %d tx, %d rx)\n",  in apple_spi_transfer_one()
436 	while (remaining_rx && retries--)  in apple_spi_transfer_one()
440 		dev_err(&ctlr->dev, "transfer completed with %d words left to transmit\n",  in apple_spi_transfer_one()
443 		dev_err(&ctlr->dev, "transfer completed with %d words left to receive\n",  in apple_spi_transfer_one()
463 	ctlr = devm_spi_alloc_host(&pdev->dev, sizeof(struct apple_spi));  in apple_spi_probe()
465 		return -ENOMEM;  in apple_spi_probe()
468 	init_completion(&spi->done);  in apple_spi_probe()
470 	spi->regs = devm_platform_ioremap_resource(pdev, 0);  in apple_spi_probe()
471 	if (IS_ERR(spi->regs))  in apple_spi_probe()
472 		return PTR_ERR(spi->regs);  in apple_spi_probe()
474 	spi->clk = devm_clk_get_enabled(&pdev->dev, NULL);  in apple_spi_probe()
475 	if (IS_ERR(spi->clk))  in apple_spi_probe()
476 		return dev_err_probe(&pdev->dev, PTR_ERR(spi->clk),  in apple_spi_probe()
483 	ret = devm_request_irq(&pdev->dev, irq, apple_spi_irq, 0,  in apple_spi_probe()
484 			       dev_name(&pdev->dev), spi);  in apple_spi_probe()
486 		return dev_err_probe(&pdev->dev, ret, "Unable to bind to interrupt\n");  in apple_spi_probe()
488 	ctlr->dev.of_node = pdev->dev.of_node;  in apple_spi_probe()
489 	ctlr->bus_num = pdev->id;  in apple_spi_probe()
490 	ctlr->num_chipselect = 1;  in apple_spi_probe()
491 	ctlr->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST;  in apple_spi_probe()
492 	ctlr->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);  in apple_spi_probe()
493 	ctlr->prepare_message = apple_spi_prepare_message;  in apple_spi_probe()
494 	ctlr->set_cs = apple_spi_set_cs;  in apple_spi_probe()
495 	ctlr->transfer_one = apple_spi_transfer_one;  in apple_spi_probe()
496 	ctlr->use_gpio_descriptors = true;  in apple_spi_probe()
497 	ctlr->auto_runtime_pm = true;  in apple_spi_probe()
499 	pm_runtime_set_active(&pdev->dev);  in apple_spi_probe()
500 	ret = devm_pm_runtime_enable(&pdev->dev);  in apple_spi_probe()
506 	ret = devm_spi_register_controller(&pdev->dev, ctlr);  in apple_spi_probe()
508 		return dev_err_probe(&pdev->dev, ret, "devm_spi_register_controller failed\n");  in apple_spi_probe()
522 		.name = "apple-spi",