sdhci-cns3xxx.c
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/*
* SDHCI support for CNS3xxx SoC
*
* Copyright 2008 Cavium Networks
* Copyright 2010 MontaVista Software, LLC.
*
* Authors: Scott Shu
* Anton Vorontsov <avorontsov@mvista.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/mmc/host.h>
#include <linux/module.h>
#include "sdhci-pltfm.h"
static unsigned int sdhci_cns3xxx_get_max_clk(struct sdhci_host *host)
{
return 150000000;
}
static void sdhci_cns3xxx_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct device *dev = mmc_dev(host->mmc);
int div = 1;
u16 clk;
unsigned long timeout;
host->mmc->actual_clock = 0;
sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
if (clock == 0)
return;
while (host->max_clk / div > clock) {
/*
* On CNS3xxx divider grows linearly up to 4, and then
* exponentially up to 256.
*/
if (div < 4)
div += 1;
else if (div < 256)
div *= 2;
else
break;
}
dev_dbg(dev, "desired SD clock: %d, actual: %d\n",
clock, host->max_clk / div);
/* Divide by 3 is special. */
if (div != 3)
div >>= 1;
clk = div << SDHCI_DIVIDER_SHIFT;
clk |= SDHCI_CLOCK_INT_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
timeout = 20;
while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
& SDHCI_CLOCK_INT_STABLE)) {
if (timeout == 0) {
dev_warn(dev, "clock is unstable");
break;
}
timeout--;
mdelay(1);
}
clk |= SDHCI_CLOCK_CARD_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
}
static const struct sdhci_ops sdhci_cns3xxx_ops = {
.get_max_clock = sdhci_cns3xxx_get_max_clk,
.set_clock = sdhci_cns3xxx_set_clock,
.set_bus_width = sdhci_set_bus_width,
.reset = sdhci_reset,
.set_uhs_signaling = sdhci_set_uhs_signaling,
};
static const struct sdhci_pltfm_data sdhci_cns3xxx_pdata = {
.ops = &sdhci_cns3xxx_ops,
.quirks = SDHCI_QUIRK_BROKEN_DMA |
SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
SDHCI_QUIRK_BROKEN_TIMEOUT_VAL,
};
static int sdhci_cns3xxx_probe(struct platform_device *pdev)
{
return sdhci_pltfm_register(pdev, &sdhci_cns3xxx_pdata, 0);
}
static struct platform_driver sdhci_cns3xxx_driver = {
.driver = {
.name = "sdhci-cns3xxx",
.pm = SDHCI_PLTFM_PMOPS,
},
.probe = sdhci_cns3xxx_probe,
.remove = sdhci_pltfm_unregister,
};
module_platform_driver(sdhci_cns3xxx_driver);
MODULE_DESCRIPTION("SDHCI driver for CNS3xxx");
MODULE_AUTHOR("Scott Shu, "
"Anton Vorontsov <avorontsov@mvista.com>");
MODULE_LICENSE("GPL v2");