xref: /openbmc/linux/drivers/spi/spi-dw-mmio.c (revision afc98d90)
1 /*
2  * Memory-mapped interface driver for DW SPI Core
3  *
4  * Copyright (c) 2010, Octasic semiconductor.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/err.h>
13 #include <linux/interrupt.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/spi/spi.h>
17 #include <linux/scatterlist.h>
18 #include <linux/module.h>
19 
20 #include "spi-dw.h"
21 
22 #define DRIVER_NAME "dw_spi_mmio"
23 
24 struct dw_spi_mmio {
25 	struct dw_spi  dws;
26 	struct clk     *clk;
27 };
28 
29 static int dw_spi_mmio_probe(struct platform_device *pdev)
30 {
31 	struct dw_spi_mmio *dwsmmio;
32 	struct dw_spi *dws;
33 	struct resource *mem;
34 	int ret;
35 
36 	dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio),
37 			GFP_KERNEL);
38 	if (!dwsmmio)
39 		return -ENOMEM;
40 
41 	dws = &dwsmmio->dws;
42 
43 	/* Get basic io resource and map it */
44 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
45 	if (!mem) {
46 		dev_err(&pdev->dev, "no mem resource?\n");
47 		return -EINVAL;
48 	}
49 
50 	dws->regs = devm_ioremap_resource(&pdev->dev, mem);
51 	if (IS_ERR(dws->regs)) {
52 		dev_err(&pdev->dev, "SPI region map failed\n");
53 		return PTR_ERR(dws->regs);
54 	}
55 
56 	dws->irq = platform_get_irq(pdev, 0);
57 	if (dws->irq < 0) {
58 		dev_err(&pdev->dev, "no irq resource?\n");
59 		return dws->irq; /* -ENXIO */
60 	}
61 
62 	dwsmmio->clk = devm_clk_get(&pdev->dev, NULL);
63 	if (IS_ERR(dwsmmio->clk))
64 		return PTR_ERR(dwsmmio->clk);
65 	ret = clk_prepare_enable(dwsmmio->clk);
66 	if (ret)
67 		return ret;
68 
69 	dws->bus_num = 0;
70 	dws->num_cs = 4;
71 	dws->max_freq = clk_get_rate(dwsmmio->clk);
72 
73 	ret = dw_spi_add_host(&pdev->dev, dws);
74 	if (ret)
75 		goto out;
76 
77 	platform_set_drvdata(pdev, dwsmmio);
78 	return 0;
79 
80 out:
81 	clk_disable_unprepare(dwsmmio->clk);
82 	return ret;
83 }
84 
85 static int dw_spi_mmio_remove(struct platform_device *pdev)
86 {
87 	struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
88 
89 	clk_disable_unprepare(dwsmmio->clk);
90 	dw_spi_remove_host(&dwsmmio->dws);
91 
92 	return 0;
93 }
94 
95 static struct platform_driver dw_spi_mmio_driver = {
96 	.probe		= dw_spi_mmio_probe,
97 	.remove		= dw_spi_mmio_remove,
98 	.driver		= {
99 		.name	= DRIVER_NAME,
100 		.owner	= THIS_MODULE,
101 	},
102 };
103 module_platform_driver(dw_spi_mmio_driver);
104 
105 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
106 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
107 MODULE_LICENSE("GPL v2");
108