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
24 enum altera_spi_type {
25 ALTERA_SPI_TYPE_UNKNOWN,
26 ALTERA_SPI_TYPE_SUBDEV,
27 };
28
29 static 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
altera_spi_probe(struct platform_device * pdev)36 static 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_master *master;
43 int err = -ENODEV;
44 u16 i;
45
46 master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
47 if (!master)
48 return err;
49
50 /* setup the master state. */
51 master->bus_num = pdev->id;
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 master->num_chipselect = pdata->num_chipselect;
63 master->mode_bits = pdata->mode_bits;
64 master->bits_per_word_mask = pdata->bits_per_word_mask;
65 } else {
66 master->num_chipselect = 16;
67 master->mode_bits = SPI_CS_HIGH;
68 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
69 }
70
71 master->dev.of_node = pdev->dev.of_node;
72
73 hw = spi_master_get_devdata(master);
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_master(master);
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, master);
117 if (err)
118 goto exit;
119 }
120
121 err = devm_spi_register_master(&pdev->dev, master);
122 if (err)
123 goto exit;
124
125 if (pdata) {
126 for (i = 0; i < pdata->num_devices; i++) {
127 if (!spi_new_device(master, 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;
137 exit:
138 spi_master_put(master);
139 return err;
140 }
141
142 #ifdef CONFIG_OF
143 static const struct of_device_id altera_spi_match[] = {
144 { .compatible = "ALTR,spi-1.0", },
145 { .compatible = "altr,spi-1.0", },
146 {},
147 };
148 MODULE_DEVICE_TABLE(of, altera_spi_match);
149 #endif /* CONFIG_OF */
150
151 static 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 };
156 MODULE_DEVICE_TABLE(platform, altera_spi_ids);
157
158 static 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 };
167 module_platform_driver(altera_spi_driver);
168
169 MODULE_DESCRIPTION("Altera SPI driver");
170 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
171 MODULE_LICENSE("GPL");
172 MODULE_ALIAS("platform:" DRV_NAME);
173