1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Altera SPI driver
  4 *
  5 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
  6 *
  7 * Based on spi_s3c24xx.c, which is:
  8 * Copyright (c) 2006 Ben Dooks
  9 * Copyright (c) 2006 Simtec Electronics
 10 *	Ben Dooks <ben@simtec.co.uk>
 11 */
 12
 13#include <linux/interrupt.h>
 14#include <linux/errno.h>
 15#include <linux/module.h>
 16#include <linux/platform_device.h>
 17#include <linux/spi/altera.h>
 18#include <linux/spi/spi.h>
 19#include <linux/io.h>
 20#include <linux/of.h>
 21
 22#define DRV_NAME "spi_altera"
 23
 24enum altera_spi_type {
 25	ALTERA_SPI_TYPE_UNKNOWN,
 26	ALTERA_SPI_TYPE_SUBDEV,
 27};
 28
 29static const struct regmap_config spi_altera_config = {
 30	.reg_bits = 32,
 31	.reg_stride = 4,
 32	.val_bits = 32,
 33	.fast_io = true,
 34};
 35
 36static int altera_spi_probe(struct platform_device *pdev)
 37{
 38	const struct platform_device_id *platid = platform_get_device_id(pdev);
 39	struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);
 40	enum altera_spi_type type = ALTERA_SPI_TYPE_UNKNOWN;
 41	struct altera_spi *hw;
 42	struct spi_controller *host;
 43	int err = -ENODEV;
 44	u16 i;
 45
 46	host = spi_alloc_host(&pdev->dev, sizeof(struct altera_spi));
 47	if (!host)
 48		return err;
 49
 50	/* setup the host state. */
 51	host->bus_num = -1;
 52
 53	if (pdata) {
 54		if (pdata->num_chipselect > ALTERA_SPI_MAX_CS) {
 55			dev_err(&pdev->dev,
 56				"Invalid number of chipselect: %u\n",
 57				pdata->num_chipselect);
 58			err = -EINVAL;
 59			goto exit;
 60		}
 61
 62		host->num_chipselect = pdata->num_chipselect;
 63		host->mode_bits = pdata->mode_bits;
 64		host->bits_per_word_mask = pdata->bits_per_word_mask;
 65	} else {
 66		host->num_chipselect = 16;
 67		host->mode_bits = SPI_CS_HIGH;
 68		host->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
 69	}
 70
 71	host->dev.of_node = pdev->dev.of_node;
 72
 73	hw = spi_controller_get_devdata(host);
 74	hw->dev = &pdev->dev;
 75
 76	if (platid)
 77		type = platid->driver_data;
 78
 79	/* find and map our resources */
 80	if (type == ALTERA_SPI_TYPE_SUBDEV) {
 81		struct resource *regoff;
 82
 83		hw->regmap = dev_get_regmap(pdev->dev.parent, NULL);
 84		if (!hw->regmap) {
 85			dev_err(&pdev->dev, "get regmap failed\n");
 86			goto exit;
 87		}
 88
 89		regoff = platform_get_resource(pdev, IORESOURCE_REG, 0);
 90		if (regoff)
 91			hw->regoff = regoff->start;
 92	} else {
 93		void __iomem *res;
 94
 95		res = devm_platform_ioremap_resource(pdev, 0);
 96		if (IS_ERR(res)) {
 97			err = PTR_ERR(res);
 98			goto exit;
 99		}
100
101		hw->regmap = devm_regmap_init_mmio(&pdev->dev, res,
102						   &spi_altera_config);
103		if (IS_ERR(hw->regmap)) {
104			dev_err(&pdev->dev, "regmap mmio init failed\n");
105			err = PTR_ERR(hw->regmap);
106			goto exit;
107		}
108	}
109
110	altera_spi_init_host(host);
111
112	/* irq is optional */
113	hw->irq = platform_get_irq(pdev, 0);
114	if (hw->irq >= 0) {
115		err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
116				       pdev->name, host);
117		if (err)
118			goto exit;
119	}
120
121	err = devm_spi_register_controller(&pdev->dev, host);
122	if (err)
123		goto exit;
124
125	if (pdata) {
126		for (i = 0; i < pdata->num_devices; i++) {
127			if (!spi_new_device(host, pdata->devices + i))
128				dev_warn(&pdev->dev,
129					 "unable to create SPI device: %s\n",
130					 pdata->devices[i].modalias);
131		}
132	}
133
134	dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq);
135
136	return 0;
137exit:
138	spi_controller_put(host);
139	return err;
140}
141
142#ifdef CONFIG_OF
143static const struct of_device_id altera_spi_match[] = {
144	{ .compatible = "ALTR,spi-1.0", },
145	{ .compatible = "altr,spi-1.0", },
146	{},
147};
148MODULE_DEVICE_TABLE(of, altera_spi_match);
149#endif /* CONFIG_OF */
150
151static const struct platform_device_id altera_spi_ids[] = {
152	{ DRV_NAME,		ALTERA_SPI_TYPE_UNKNOWN },
153	{ "subdev_spi_altera",	ALTERA_SPI_TYPE_SUBDEV },
154	{ }
155};
156MODULE_DEVICE_TABLE(platform, altera_spi_ids);
157
158static struct platform_driver altera_spi_driver = {
159	.probe = altera_spi_probe,
160	.driver = {
161		.name = DRV_NAME,
162		.pm = NULL,
163		.of_match_table = of_match_ptr(altera_spi_match),
164	},
165	.id_table	= altera_spi_ids,
166};
167module_platform_driver(altera_spi_driver);
168
169MODULE_DESCRIPTION("Altera SPI driver");
170MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
171MODULE_LICENSE("GPL");
172MODULE_ALIAS("platform:" DRV_NAME);