spi-altera-platform.c

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