1 // SPDX-License-Identifier: GPL-2.0-only
3  * SPI controller driver for the Mikrotik RB4xx boards
15 #include <linux/clk.h>
16 #include <linux/spi/spi.h>
19 #include <asm/mach-ath79/ar71xx_regs.h>
23 	struct clk *clk;  member
28 	return __raw_readl(rbspi->base + reg);  in rb4xx_read()
33 	__raw_writel(value, rbspi->base + reg);  in rb4xx_write()
52 	for (i = 7; i >= 0; i--)  in do_spi_byte()
81 static void rb4xx_set_cs(struct spi_device *spi, bool enable)  in rb4xx_set_cs()  argument
83 	struct rb4xx_spi *rbspi = spi_master_get_devdata(spi->master);  in rb4xx_set_cs()
96 			      struct spi_device *spi, struct spi_transfer *t)  in rb4xx_transfer_one()  argument
105 	 * Prime the SPI register with the SPI device selected. The m25p80 boot  in rb4xx_transfer_one()
110 	if (spi->chip_select == 2)  in rb4xx_transfer_one()
117 	tx_buf = t->tx_buf;  in rb4xx_transfer_one()
118 	rx_buf = t->rx_buf;  in rb4xx_transfer_one()
119 	for (i = 0; i < t->len; ++i) {  in rb4xx_transfer_one()
120 		if (t->tx_nbits == SPI_NBITS_DUAL)  in rb4xx_transfer_one()
121 			/* CPLD can use two-wire transfers */  in rb4xx_transfer_one()
137 	struct clk *ahb_clk;  in rb4xx_spi_probe()
146 	master = devm_spi_alloc_master(&pdev->dev, sizeof(*rbspi));  in rb4xx_spi_probe()
148 		return -ENOMEM;  in rb4xx_spi_probe()
150 	ahb_clk = devm_clk_get(&pdev->dev, "ahb");  in rb4xx_spi_probe()
154 	master->dev.of_node = pdev->dev.of_node;  in rb4xx_spi_probe()
155 	master->bus_num = 0;  in rb4xx_spi_probe()
156 	master->num_chipselect = 3;  in rb4xx_spi_probe()
157 	master->mode_bits = SPI_TX_DUAL;  in rb4xx_spi_probe()
158 	master->bits_per_word_mask = SPI_BPW_MASK(8);  in rb4xx_spi_probe()
159 	master->flags = SPI_MASTER_MUST_TX;  in rb4xx_spi_probe()
160 	master->transfer_one = rb4xx_transfer_one;  in rb4xx_spi_probe()
161 	master->set_cs = rb4xx_set_cs;  in rb4xx_spi_probe()
164 	rbspi->base = spi_base;  in rb4xx_spi_probe()
165 	rbspi->clk = ahb_clk;  in rb4xx_spi_probe()
168 	err = devm_spi_register_master(&pdev->dev, master);  in rb4xx_spi_probe()
170 		dev_err(&pdev->dev, "failed to register SPI master\n");  in rb4xx_spi_probe()
178 	/* Enable SPI */  in rb4xx_spi_probe()
188 	clk_disable_unprepare(rbspi->clk);  in rb4xx_spi_remove()
194 	{ .compatible = "mikrotik,rb4xx-spi" },
203 		.name = "rb4xx-spi",
210 MODULE_DESCRIPTION("Mikrotik RB4xx SPI controller driver");