1 // SPDX-License-Identifier: GPL-2.0
7 // Based on spi-mt7621.c:
9 // Copyright (C) 2011-2013 Gabor Juhos <juhosg@openwrt.org>
10 // Copyright (C) 2014-2015 Felix Fietkau <nbd@nbd.name>
20 #define DRIVER_NAME "spi-ar934x"
37 #define AR934X_SPI_SHIFT_VAL(cs, term, count)			\  argument
39 	(term) << AR934X_SPI_SHIFT_TERM | (count))
52 	int div = DIV_ROUND_UP(sp->clk_freq, freq * 2) - 1;  in ar934x_spi_clk_div()
57 		return -EINVAL;  in ar934x_spi_clk_div()
64 	struct ar934x_spi *sp = spi_controller_get_devdata(spi->master);  in ar934x_spi_setup()
66 	if ((spi->max_speed_hz == 0) ||  in ar934x_spi_setup()
67 	    (spi->max_speed_hz > (sp->clk_freq / 2))) {  in ar934x_spi_setup()
68 		spi->max_speed_hz = sp->clk_freq / 2;  in ar934x_spi_setup()
69 	} else if (spi->max_speed_hz < (sp->clk_freq / 128)) {  in ar934x_spi_setup()
70 		dev_err(&spi->dev, "spi clock is too low\n");  in ar934x_spi_setup()
71 		return -EINVAL;  in ar934x_spi_setup()
82 	struct spi_device *spi = m->spi;  in ar934x_spi_transfer_one_message()
83 	unsigned long trx_done, trx_cur;  in ar934x_spi_transfer_one_message()
85 	u8 term = 0;  in ar934x_spi_transfer_one_message()  local
91 	m->actual_length = 0;  in ar934x_spi_transfer_one_message()
92 	list_for_each_entry(t, &m->transfers, transfer_list) {  in ar934x_spi_transfer_one_message()
93 		if (t->speed_hz)  in ar934x_spi_transfer_one_message()
94 			div = ar934x_spi_clk_div(sp, t->speed_hz);  in ar934x_spi_transfer_one_message()
96 			div = ar934x_spi_clk_div(sp, spi->max_speed_hz);  in ar934x_spi_transfer_one_message()
98 			stat = -EIO;  in ar934x_spi_transfer_one_message()
102 		reg = ioread32(sp->base + AR934X_SPI_REG_CTRL);  in ar934x_spi_transfer_one_message()
105 		iowrite32(reg, sp->base + AR934X_SPI_REG_CTRL);  in ar934x_spi_transfer_one_message()
106 		iowrite32(0, sp->base + AR934X_SPI_DATAOUT);  in ar934x_spi_transfer_one_message()
108 		for (trx_done = 0; trx_done < t->len; trx_done += 4) {  in ar934x_spi_transfer_one_message()
109 			trx_cur = t->len - trx_done;  in ar934x_spi_transfer_one_message()
112 			else if (list_is_last(&t->transfer_list, &m->transfers))  in ar934x_spi_transfer_one_message()
113 				term = 1;  in ar934x_spi_transfer_one_message()
115 			if (t->tx_buf) {  in ar934x_spi_transfer_one_message()
116 				tx_buf = t->tx_buf + trx_done;  in ar934x_spi_transfer_one_message()
120 				iowrite32(reg, sp->base + AR934X_SPI_DATAOUT);  in ar934x_spi_transfer_one_message()
123 			reg = AR934X_SPI_SHIFT_VAL(spi->chip_select, term,  in ar934x_spi_transfer_one_message()
125 			iowrite32(reg, sp->base + AR934X_SPI_REG_SHIFT_CTRL);  in ar934x_spi_transfer_one_message()
127 				sp->base + AR934X_SPI_REG_SHIFT_CTRL, reg,  in ar934x_spi_transfer_one_message()
132 			if (t->rx_buf) {  in ar934x_spi_transfer_one_message()
133 				reg = ioread32(sp->base + AR934X_SPI_DATAIN);  in ar934x_spi_transfer_one_message()
134 				buf = t->rx_buf + trx_done;  in ar934x_spi_transfer_one_message()
136 					buf[trx_cur - i - 1] = reg & 0xff;  in ar934x_spi_transfer_one_message()
141 		m->actual_length += t->len;  in ar934x_spi_transfer_one_message()
145 	m->status = stat;  in ar934x_spi_transfer_one_message()
152 	{ .compatible = "qca,ar934x-spi" },
169 	clk = devm_clk_get(&pdev->dev, NULL);  in ar934x_spi_probe()
171 		dev_err(&pdev->dev, "failed to get clock\n");  in ar934x_spi_probe()
179 	ctlr = spi_alloc_master(&pdev->dev, sizeof(*sp));  in ar934x_spi_probe()
181 		dev_info(&pdev->dev, "failed to allocate spi controller\n");  in ar934x_spi_probe()
182 		return -ENOMEM;  in ar934x_spi_probe()
190 	ctlr->mode_bits = SPI_LSB_FIRST;  in ar934x_spi_probe()
191 	ctlr->setup = ar934x_spi_setup;  in ar934x_spi_probe()
192 	ctlr->transfer_one_message = ar934x_spi_transfer_one_message;  in ar934x_spi_probe()
193 	ctlr->bits_per_word_mask = SPI_BPW_MASK(8);  in ar934x_spi_probe()
194 	ctlr->dev.of_node = pdev->dev.of_node;  in ar934x_spi_probe()
195 	ctlr->num_chipselect = 3;  in ar934x_spi_probe()
197 	dev_set_drvdata(&pdev->dev, ctlr);  in ar934x_spi_probe()
200 	sp->base = base;  in ar934x_spi_probe()
201 	sp->clk = clk;  in ar934x_spi_probe()
202 	sp->clk_freq = clk_get_rate(clk);  in ar934x_spi_probe()
203 	sp->ctlr = ctlr;  in ar934x_spi_probe()
205 	return devm_spi_register_controller(&pdev->dev, ctlr);  in ar934x_spi_probe()
213 	ctlr = dev_get_drvdata(&pdev->dev);  in ar934x_spi_remove()
216 	clk_disable_unprepare(sp->clk);  in ar934x_spi_remove()