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20b1597b AV |
1 | /* |
2 | * SDHCI support for CNS3xxx SoC | |
3 | * | |
4 | * Copyright 2008 Cavium Networks | |
5 | * Copyright 2010 MontaVista Software, LLC. | |
6 | * | |
7 | * Authors: Scott Shu | |
8 | * Anton Vorontsov <avorontsov@mvista.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | */ | |
14 | ||
15 | #include <linux/delay.h> | |
16 | #include <linux/device.h> | |
17 | #include <linux/mmc/host.h> | |
7833c66b | 18 | #include <linux/module.h> |
20b1597b | 19 | #include <mach/cns3xxx.h> |
20b1597b AV |
20 | #include "sdhci-pltfm.h" |
21 | ||
22 | static unsigned int sdhci_cns3xxx_get_max_clk(struct sdhci_host *host) | |
23 | { | |
24 | return 150000000; | |
25 | } | |
26 | ||
27 | static void sdhci_cns3xxx_set_clock(struct sdhci_host *host, unsigned int clock) | |
28 | { | |
29 | struct device *dev = mmc_dev(host->mmc); | |
30 | int div = 1; | |
31 | u16 clk; | |
32 | unsigned long timeout; | |
33 | ||
34 | if (clock == host->clock) | |
35 | return; | |
36 | ||
37 | sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL); | |
38 | ||
39 | if (clock == 0) | |
40 | goto out; | |
41 | ||
42 | while (host->max_clk / div > clock) { | |
43 | /* | |
44 | * On CNS3xxx divider grows linearly up to 4, and then | |
45 | * exponentially up to 256. | |
46 | */ | |
47 | if (div < 4) | |
48 | div += 1; | |
49 | else if (div < 256) | |
50 | div *= 2; | |
51 | else | |
52 | break; | |
53 | } | |
54 | ||
55 | dev_dbg(dev, "desired SD clock: %d, actual: %d\n", | |
56 | clock, host->max_clk / div); | |
57 | ||
58 | /* Divide by 3 is special. */ | |
59 | if (div != 3) | |
60 | div >>= 1; | |
61 | ||
62 | clk = div << SDHCI_DIVIDER_SHIFT; | |
63 | clk |= SDHCI_CLOCK_INT_EN; | |
64 | sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); | |
65 | ||
66 | timeout = 20; | |
67 | while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL)) | |
68 | & SDHCI_CLOCK_INT_STABLE)) { | |
69 | if (timeout == 0) { | |
70 | dev_warn(dev, "clock is unstable"); | |
71 | break; | |
72 | } | |
73 | timeout--; | |
74 | mdelay(1); | |
75 | } | |
76 | ||
77 | clk |= SDHCI_CLOCK_CARD_EN; | |
78 | sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); | |
79 | out: | |
80 | host->clock = clock; | |
81 | } | |
82 | ||
83 | static struct sdhci_ops sdhci_cns3xxx_ops = { | |
84 | .get_max_clock = sdhci_cns3xxx_get_max_clk, | |
85 | .set_clock = sdhci_cns3xxx_set_clock, | |
86 | }; | |
87 | ||
85d6509d | 88 | static struct sdhci_pltfm_data sdhci_cns3xxx_pdata = { |
20b1597b AV |
89 | .ops = &sdhci_cns3xxx_ops, |
90 | .quirks = SDHCI_QUIRK_BROKEN_DMA | | |
91 | SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK | | |
92 | SDHCI_QUIRK_INVERTED_WRITE_PROTECT | | |
93 | SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN | | |
94 | SDHCI_QUIRK_BROKEN_TIMEOUT_VAL | | |
95 | SDHCI_QUIRK_NONSTANDARD_CLOCK, | |
96 | }; | |
85d6509d SG |
97 | |
98 | static int __devinit sdhci_cns3xxx_probe(struct platform_device *pdev) | |
99 | { | |
100 | return sdhci_pltfm_register(pdev, &sdhci_cns3xxx_pdata); | |
101 | } | |
102 | ||
103 | static int __devexit sdhci_cns3xxx_remove(struct platform_device *pdev) | |
104 | { | |
105 | return sdhci_pltfm_unregister(pdev); | |
106 | } | |
107 | ||
108 | static struct platform_driver sdhci_cns3xxx_driver = { | |
109 | .driver = { | |
110 | .name = "sdhci-cns3xxx", | |
111 | .owner = THIS_MODULE, | |
112 | }, | |
113 | .probe = sdhci_cns3xxx_probe, | |
114 | .remove = __devexit_p(sdhci_cns3xxx_remove), | |
115 | #ifdef CONFIG_PM | |
116 | .suspend = sdhci_pltfm_suspend, | |
117 | .resume = sdhci_pltfm_resume, | |
118 | #endif | |
119 | }; | |
120 | ||
121 | static int __init sdhci_cns3xxx_init(void) | |
122 | { | |
123 | return platform_driver_register(&sdhci_cns3xxx_driver); | |
124 | } | |
125 | module_init(sdhci_cns3xxx_init); | |
126 | ||
127 | static void __exit sdhci_cns3xxx_exit(void) | |
128 | { | |
129 | platform_driver_unregister(&sdhci_cns3xxx_driver); | |
130 | } | |
131 | module_exit(sdhci_cns3xxx_exit); | |
132 | ||
133 | MODULE_DESCRIPTION("SDHCI driver for CNS3xxx"); | |
134 | MODULE_AUTHOR("Scott Shu, " | |
135 | "Anton Vorontsov <avorontsov@mvista.com>"); | |
136 | MODULE_LICENSE("GPL v2"); |