1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * SPI host driver for ICP DAS LP-8841 RTC
11  * Copyright (C) 2003 - 2007 Paul Mundt
43 		data->state |= SPI_LP8841_RTC_CLK;  in setsck()
45 		data->state &= ~SPI_LP8841_RTC_CLK;  in setsck()
46 	writeb(data->state, data->iomem);  in setsck()
53 		data->state |= SPI_LP8841_RTC_MOSI;  in setmosi()
55 		data->state &= ~SPI_LP8841_RTC_MOSI;  in setmosi()
56 	writeb(data->state, data->iomem);  in setmosi()
62 	return ioread8(data->iomem) & SPI_LP8841_RTC_MISO;  in getmiso()
72 	u32 shift = 32 - bits;  in bitbang_txrx_be_cpha0_lsb()
73 	/* clock starts at inactive polarity */  in bitbang_txrx_be_cpha0_lsb()
74 	for (; likely(bits); bits--) {  in bitbang_txrx_be_cpha0_lsb()
103 	unsigned		count = t->len;  in spi_lp8841_rtc_transfer_one()
104 	const u8		*tx = t->tx_buf;  in spi_lp8841_rtc_transfer_one()
105 	u8			*rx = t->rx_buf;  in spi_lp8841_rtc_transfer_one()  local
110 		data->state &= ~SPI_LP8841_RTC_nWE;  in spi_lp8841_rtc_transfer_one()
111 		writeb(data->state, data->iomem);  in spi_lp8841_rtc_transfer_one()
116 			count--;  in spi_lp8841_rtc_transfer_one()
118 	} else if (rx) {  in spi_lp8841_rtc_transfer_one()
119 		data->state |= SPI_LP8841_RTC_nWE;  in spi_lp8841_rtc_transfer_one()
120 		writeb(data->state, data->iomem);  in spi_lp8841_rtc_transfer_one()
124 			*rx++ = word;  in spi_lp8841_rtc_transfer_one()
125 			count--;  in spi_lp8841_rtc_transfer_one()
128 		ret = -EINVAL;  in spi_lp8841_rtc_transfer_one()
139 	struct spi_lp8841_rtc *data = spi_controller_get_devdata(spi->controller);  in spi_lp8841_rtc_set_cs()
141 	data->state = 0;  in spi_lp8841_rtc_set_cs()
142 	writeb(data->state, data->iomem);  in spi_lp8841_rtc_set_cs()
145 		data->state |= SPI_LP8841_RTC_CE;  in spi_lp8841_rtc_set_cs()
146 		writeb(data->state, data->iomem);  in spi_lp8841_rtc_set_cs()
154 	if ((spi->mode & SPI_CS_HIGH) == 0) {  in spi_lp8841_rtc_setup()
155 		dev_err(&spi->dev, "unsupported active low chip select\n");  in spi_lp8841_rtc_setup()
156 		return -EINVAL;  in spi_lp8841_rtc_setup()
159 	if ((spi->mode & SPI_LSB_FIRST) == 0) {  in spi_lp8841_rtc_setup()
160 		dev_err(&spi->dev, "unsupported MSB first mode\n");  in spi_lp8841_rtc_setup()
161 		return -EINVAL;  in spi_lp8841_rtc_setup()
164 	if ((spi->mode & SPI_3WIRE) == 0) {  in spi_lp8841_rtc_setup()
165 		dev_err(&spi->dev, "unsupported wiring. 3 wires required\n");  in spi_lp8841_rtc_setup()
166 		return -EINVAL;  in spi_lp8841_rtc_setup()
174 	{ .compatible = "icpdas,lp8841-spi-rtc" },
188 	host = spi_alloc_host(&pdev->dev, sizeof(*data));  in spi_lp8841_rtc_probe()
190 		return -ENOMEM;  in spi_lp8841_rtc_probe()
193 	host->flags = SPI_CONTROLLER_HALF_DUPLEX;  in spi_lp8841_rtc_probe()
194 	host->mode_bits = SPI_CS_HIGH | SPI_3WIRE | SPI_LSB_FIRST;  in spi_lp8841_rtc_probe()
196 	host->bus_num = pdev->id;  in spi_lp8841_rtc_probe()
197 	host->num_chipselect = 1;  in spi_lp8841_rtc_probe()
198 	host->setup = spi_lp8841_rtc_setup;  in spi_lp8841_rtc_probe()
199 	host->set_cs = spi_lp8841_rtc_set_cs;  in spi_lp8841_rtc_probe()
200 	host->transfer_one = spi_lp8841_rtc_transfer_one;  in spi_lp8841_rtc_probe()
201 	host->bits_per_word_mask = SPI_BPW_MASK(8);  in spi_lp8841_rtc_probe()
203 	host->dev.of_node = pdev->dev.of_node;  in spi_lp8841_rtc_probe()
208 	data->iomem = devm_platform_ioremap_resource(pdev, 0);  in spi_lp8841_rtc_probe()
209 	ret = PTR_ERR_OR_ZERO(data->iomem);  in spi_lp8841_rtc_probe()
211 		dev_err(&pdev->dev, "failed to get IO address\n");  in spi_lp8841_rtc_probe()
216 	ret = devm_spi_register_controller(&pdev->dev, host);  in spi_lp8841_rtc_probe()
218 		dev_err(&pdev->dev, "cannot register spi host\n");  in spi_lp8841_rtc_probe()
242 MODULE_DESCRIPTION("SPI host driver for ICP DAS LP-8841 RTC");