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
dw_spi_mmio_probe(struct platform_device * pdev)29 static int __devinit dw_spi_mmio_probe(struct platform_device *pdev)
30 {
31 struct dw_spi_mmio *dwsmmio;
32 struct dw_spi *dws;
33 struct resource *mem, *ioarea;
34 int ret;
35
36 dwsmmio = kzalloc(sizeof(struct dw_spi_mmio), GFP_KERNEL);
37 if (!dwsmmio) {
38 ret = -ENOMEM;
39 goto err_end;
40 }
41
42 dws = &dwsmmio->dws;
43
44 /* Get basic io resource and map it */
45 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
46 if (!mem) {
47 dev_err(&pdev->dev, "no mem resource?\n");
48 ret = -EINVAL;
49 goto err_kfree;
50 }
51
52 ioarea = request_mem_region(mem->start, resource_size(mem),
53 pdev->name);
54 if (!ioarea) {
55 dev_err(&pdev->dev, "SPI region already claimed\n");
56 ret = -EBUSY;
57 goto err_kfree;
58 }
59
60 dws->regs = ioremap_nocache(mem->start, resource_size(mem));
61 if (!dws->regs) {
62 dev_err(&pdev->dev, "SPI region already mapped\n");
63 ret = -ENOMEM;
64 goto err_release_reg;
65 }
66
67 dws->irq = platform_get_irq(pdev, 0);
68 if (dws->irq < 0) {
69 dev_err(&pdev->dev, "no irq resource?\n");
70 ret = dws->irq; /* -ENXIO */
71 goto err_unmap;
72 }
73
74 dwsmmio->clk = clk_get(&pdev->dev, NULL);
75 if (IS_ERR(dwsmmio->clk)) {
76 ret = PTR_ERR(dwsmmio->clk);
77 goto err_irq;
78 }
79 clk_enable(dwsmmio->clk);
80
81 dws->parent_dev = &pdev->dev;
82 dws->bus_num = 0;
83 dws->num_cs = 4;
84 dws->max_freq = clk_get_rate(dwsmmio->clk);
85
86 ret = dw_spi_add_host(dws);
87 if (ret)
88 goto err_clk;
89
90 platform_set_drvdata(pdev, dwsmmio);
91 return 0;
92
93 err_clk:
94 clk_disable(dwsmmio->clk);
95 clk_put(dwsmmio->clk);
96 dwsmmio->clk = NULL;
97 err_irq:
98 free_irq(dws->irq, dws);
99 err_unmap:
100 iounmap(dws->regs);
101 err_release_reg:
102 release_mem_region(mem->start, resource_size(mem));
103 err_kfree:
104 kfree(dwsmmio);
105 err_end:
106 return ret;
107 }
108
dw_spi_mmio_remove(struct platform_device * pdev)109 static int __devexit dw_spi_mmio_remove(struct platform_device *pdev)
110 {
111 struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
112 struct resource *mem;
113
114 platform_set_drvdata(pdev, NULL);
115
116 clk_disable(dwsmmio->clk);
117 clk_put(dwsmmio->clk);
118 dwsmmio->clk = NULL;
119
120 free_irq(dwsmmio->dws.irq, &dwsmmio->dws);
121 dw_spi_remove_host(&dwsmmio->dws);
122 iounmap(dwsmmio->dws.regs);
123 kfree(dwsmmio);
124
125 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
126 release_mem_region(mem->start, resource_size(mem));
127 return 0;
128 }
129
130 static struct platform_driver dw_spi_mmio_driver = {
131 .probe = dw_spi_mmio_probe,
132 .remove = __devexit_p(dw_spi_mmio_remove),
133 .driver = {
134 .name = DRIVER_NAME,
135 .owner = THIS_MODULE,
136 },
137 };
138 module_platform_driver(dw_spi_mmio_driver);
139
140 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
141 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
142 MODULE_LICENSE("GPL v2");
143