projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 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, | |
| 29495aa0 | 112 | .pm = SDHCI_PLTFM_PMOPS, |
| 85d6509d SG |
113 | }, |
| 114 | .probe = sdhci_cns3xxx_probe, | |
| 115 | .remove = __devexit_p(sdhci_cns3xxx_remove), | |
| 85d6509d SG |
116 | }; |
| 117 | ||
| 118 | static int __init sdhci_cns3xxx_init(void) | |
| 119 | { | |
| 120 | return platform_driver_register(&sdhci_cns3xxx_driver); | |
| 121 | } | |
| 122 | module_init(sdhci_cns3xxx_init); | |
| 123 | ||
| 124 | static void __exit sdhci_cns3xxx_exit(void) | |
| 125 | { | |
| 126 | platform_driver_unregister(&sdhci_cns3xxx_driver); | |
| 127 | } | |
| 128 | module_exit(sdhci_cns3xxx_exit); | |
| 129 | ||
| 130 | MODULE_DESCRIPTION("SDHCI driver for CNS3xxx"); | |
| 131 | MODULE_AUTHOR("Scott Shu, " | |
| 132 | "Anton Vorontsov <avorontsov@mvista.com>"); | |
| 133 | MODULE_LICENSE("GPL v2"); |