spi: tegra: Fixed spi slave CS polarity
[linux-2.6.git] / drivers / spi / spi-dw-mmio.c
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
19 #include "spi-dw.h"
20
21 #define DRIVER_NAME "dw_spi_mmio"
22
23 struct dw_spi_mmio {
24         struct dw_spi  dws;
25         struct clk     *clk;
26 };
27
28 static int __devinit dw_spi_mmio_probe(struct platform_device *pdev)
29 {
30         struct dw_spi_mmio *dwsmmio;
31         struct dw_spi *dws;
32         struct resource *mem, *ioarea;
33         int ret;
34
35         dwsmmio = kzalloc(sizeof(struct dw_spi_mmio), GFP_KERNEL);
36         if (!dwsmmio) {
37                 ret = -ENOMEM;
38                 goto err_end;
39         }
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                 ret = -EINVAL;
48                 goto err_kfree;
49         }
50
51         ioarea = request_mem_region(mem->start, resource_size(mem),
52                         pdev->name);
53         if (!ioarea) {
54                 dev_err(&pdev->dev, "SPI region already claimed\n");
55                 ret = -EBUSY;
56                 goto err_kfree;
57         }
58
59         dws->regs = ioremap_nocache(mem->start, resource_size(mem));
60         if (!dws->regs) {
61                 dev_err(&pdev->dev, "SPI region already mapped\n");
62                 ret = -ENOMEM;
63                 goto err_release_reg;
64         }
65
66         dws->irq = platform_get_irq(pdev, 0);
67         if (dws->irq < 0) {
68                 dev_err(&pdev->dev, "no irq resource?\n");
69                 ret = dws->irq; /* -ENXIO */
70                 goto err_unmap;
71         }
72
73         dwsmmio->clk = clk_get(&pdev->dev, NULL);
74         if (IS_ERR(dwsmmio->clk)) {
75                 ret = PTR_ERR(dwsmmio->clk);
76                 goto err_irq;
77         }
78         clk_enable(dwsmmio->clk);
79
80         dws->parent_dev = &pdev->dev;
81         dws->bus_num = 0;
82         dws->num_cs = 4;
83         dws->max_freq = clk_get_rate(dwsmmio->clk);
84
85         ret = dw_spi_add_host(dws);
86         if (ret)
87                 goto err_clk;
88
89         platform_set_drvdata(pdev, dwsmmio);
90         return 0;
91
92 err_clk:
93         clk_disable(dwsmmio->clk);
94         clk_put(dwsmmio->clk);
95         dwsmmio->clk = NULL;
96 err_irq:
97         free_irq(dws->irq, dws);
98 err_unmap:
99         iounmap(dws->regs);
100 err_release_reg:
101         release_mem_region(mem->start, resource_size(mem));
102 err_kfree:
103         kfree(dwsmmio);
104 err_end:
105         return ret;
106 }
107
108 static int __devexit dw_spi_mmio_remove(struct platform_device *pdev)
109 {
110         struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
111         struct resource *mem;
112
113         platform_set_drvdata(pdev, NULL);
114
115         clk_disable(dwsmmio->clk);
116         clk_put(dwsmmio->clk);
117         dwsmmio->clk = NULL;
118
119         free_irq(dwsmmio->dws.irq, &dwsmmio->dws);
120         dw_spi_remove_host(&dwsmmio->dws);
121         iounmap(dwsmmio->dws.regs);
122         kfree(dwsmmio);
123
124         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
125         release_mem_region(mem->start, resource_size(mem));
126         return 0;
127 }
128
129 static struct platform_driver dw_spi_mmio_driver = {
130         .remove         = __devexit_p(dw_spi_mmio_remove),
131         .driver         = {
132                 .name   = DRIVER_NAME,
133                 .owner  = THIS_MODULE,
134         },
135 };
136
137 static int __init dw_spi_mmio_init(void)
138 {
139         return platform_driver_probe(&dw_spi_mmio_driver, dw_spi_mmio_probe);
140 }
141 module_init(dw_spi_mmio_init);
142
143 static void __exit dw_spi_mmio_exit(void)
144 {
145         platform_driver_unregister(&dw_spi_mmio_driver);
146 }
147 module_exit(dw_spi_mmio_exit);
148
149 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
150 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
151 MODULE_LICENSE("GPL v2");