114 lines
2.6 KiB
C
114 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* SDHCI support for CNS3xxx SoC
|
|
*
|
|
* Copyright 2008 Cavium Networks
|
|
* Copyright 2010 MontaVista Software, LLC.
|
|
*
|
|
* Authors: Scott Shu
|
|
* Anton Vorontsov <avorontsov@mvista.com>
|
|
*/
|
|
|
|
#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",
|
|
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
|
|
.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");
|