/* linux/drivers/mmc/host/sdhci-s3c.c
*
* Copyright 2008 Openmoko Inc.
* Copyright 2008 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
* http://armlinux.simtec.co.uk/
*
* SDHCI (HSMMC) support for Samsung SoC
*
* 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/dma-mapping.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/mmc/host.h>
#include <plat/sdhci.h>
#include <plat/regs-sdhci.h>
#include "sdhci.h"
#define MAX_BUS_CLK (4)
/**
* struct sdhci_s3c - S3C SDHCI instance
* @host: The SDHCI host created
* @pdev: The platform device we where created from.
* @ioarea: The resource created when we claimed the IO area.
* @pdata: The platform data for this controller.
* @cur_clk: The index of the current bus clock.
* @clk_io: The clock for the internal bus interface.
* @clk_bus: The clocks that are available for the SD/MMC bus clock.
*/
struct sdhci_s3c {
struct sdhci_host *host;
struct platform_device *pdev;
struct resource *ioarea;
struct s3c_sdhci_platdata *pdata;
unsigned int cur_clk;
struct clk *clk_io;
struct clk *clk_bus[MAX_BUS_CLK];
};
static inline struct sdhci_s3c *to_s3c(struct sdhci_host *host)
{
return sdhci_priv(host);
}
/**
* get_curclk - convert ctrl2 register to clock source number
* @ctrl2: Control2 register value.
*/
static u32 get_curclk(u32 ctrl2)
{
ctrl2 &= S3C_SDHCI_CTRL2_SELBASECLK_MASK;
ctrl2 >>= S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
return ctrl2;
}
static void sdhci_s3c_check_sclk(struct sdhci_host *host)
{
struct sdhci_s3c *ourhost = to_s3c(host);
u32 tmp = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
if (get_curclk(tmp) != ourhost->cur_clk) {
dev_dbg(&ourhost->pdev->dev, "restored ctrl2 clock setting\n");
tmp &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
tmp |= ourhost->cur_clk << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
writel(tmp, host->ioaddr + 0x80);
}
}
/**
* sdhci_s3c_get_max_clk - callback to get maximum clock frequency.
* @host: The SDHCI host instance.
*
* Callback to return the maximum clock rate acheivable by the controller.
*/
static unsigned int sdhci_s3c_get_max_clk(struct sdhci_host *host)
{
struct sdhci_s3c *ourhost = to_s3c(host);
struct clk *busclk;
unsigned int rate, max;
int clk;
/* note, a reset will reset the clock source */
sdhci_s3c_check_sclk(host);
for (max = 0, clk = 0; clk < MAX_BUS_CLK; clk++) {
busclk = ourhost->clk_bus[clk];
if (!busclk)
continue;
rate = clk_get_rate(busclk);
if (rate > max)
max = rate;
}
return max;
}
static unsigned int sdhci_s3c_get_timeout_clk(struct sdhci_host *host)
{
return sdhci_s3c_get_max_clk(host) / 1000000;
}
/**
* sdhci_s3c_consider_clock - consider one the bus clocks for current setting
* @ourhost: Our SDHCI instance.
* @src: The source clock index.
* @wanted: The clock frequency wanted.
*/
static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
unsigned int src,
unsigned int wanted)
{
unsigned long rate;
struct clk *clksrc = ourhost->clk_bus[src];
int div;
if (!clksrc)
return UINT_MAX;
rate = clk_get_rate(clksrc);
for (div = 1; div < 256; div *= 2) {
if ((rate / div) <= wanted)
break;
}
dev_dbg(&ourhost->pdev->dev, "clk %d: rate %ld, want %d, got %ld\n",
src, rate, wanted, rate / div);
return (wanted - (rate / div));
}
/**
* sdhci_s3c_set_clock - callback on clock change
* @host: The SDHCI host being changed
* @clock: The clock rate being requested.
*
* When the card's clock is going to be changed, look at the new frequency
* and find the best clock source to go with it.
*/
static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct sdhci_s3c *ourhost = to_s3c(host);
unsigned int best = UINT_MAX;
unsigned int delta;
int best_src = 0;
int src;
u32 ctrl;
/* don't bother if the clock is going off. */
if (clock == 0)
return;
for (src = 0; src < MAX_BUS_CLK; src++) {
delta = sdhci_s3c_consider_clock(ourhost, src, clock);
if (delta < best) {
best = delta;
best_src = src;
}
}
dev_dbg(&ourhost->pdev->dev,
"selected source %d, clock %d, delta %d\n",
best_src, clock, best);
/* select the new clock source */
if (ourhost->cur_clk != best_src) {
struct clk *clk = ourhost->clk_bus[best_src];
/* turn clock off to card before changing clock source */
writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
ourhost->cur_clk = best_src;
host->max_clk = clk_get_rate(clk);
host->timeout_clk = sdhci_s3c_get_timeout_clk(host);
ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
ctrl |= best_src << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL2);
}
/* reconfigure the hardware for new clock rate */
{
struct mmc_ios ios;
ios.clock = clock;
if (ourhost->pdata->cfg_card)
(ourhost->pdata->cfg_card)(ourhost->pdev, host->ioaddr,
&ios, NULL);
}
}
static struct sdhci_ops sdhci_s3c_ops = {
.get_max_clock = sdhci_s3c_get_max_clk,
.get_timeout_clock = sdhci_s3c_get_timeout_clk,
.set_clock = sdhci_s3c_set_clock,
};
static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
{
struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
struct device *dev = &pdev->dev;
struct sdhci_host *host;
struct sdhci_s3c *sc;
struct resource *res;
int ret, irq, ptr, clks;
if (!pdata) {
dev_err(dev, "no device data specified\n");
return -ENOENT;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(dev, "no irq specified\n");
return irq;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(dev, "no memory specified\n");
return -ENOENT;
}
host = sdhci_alloc_host(dev, sizeof(struct sdhci_s3c));
if (IS_ERR(host)) {
dev_err(dev, "sdhci_alloc_host() failed\n");
return PTR_ERR(host);
}
sc = sdhci_priv(host);
sc->host = host;
sc->pdev = pdev;
sc->pdata = pdata;
platform_set_drvdata(pdev, host);
sc->clk_io = clk_get(dev, "hsmmc");
if (IS_ERR(sc->clk_io)) {
dev_err(dev, "failed to get io clock\n");
ret = PTR_ERR(sc->clk_io);
goto err_io_clk;
}
/* enable the local io clock and keep it running for the moment. */
clk_enable(sc->clk_io);
for (clks = 0, ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
struct clk *clk;
char *name = pdata->clocks[ptr];
if (name == NULL)
continue;
clk = clk_get(dev, name);
if (IS_ERR(clk)) {
dev_err(dev, "failed to get clock %s\n", name);
continue;
}
clks++;
sc->clk_bus[ptr] = clk;
clk_enable(clk);
dev_info(dev, "clock source %d: %s (%ld Hz)\n",
ptr, name, clk_get_rate(clk));
}
if (clks == 0) {
dev_err(dev, "failed to find any bus clocks\n");
ret = -ENOENT;
goto err_no_busclks;
}
sc->ioarea = request_mem_region(res->start, resource_size(res),
mmc_hostname(host->mmc));
if (!sc->ioarea) {
dev_err(dev, "failed to reserve register area\n");
ret = -ENXIO;
goto err_req_regs;
}
host->ioaddr = ioremap_nocache(res->start, resource_size(res));
if (!host->ioaddr) {
dev_err(dev, "failed to map registers\n");
ret = -ENXIO;
goto err_req_regs;
}
/* Ensure we have minimal gpio selected CMD/CLK/Detect */
if (pdata->cfg_gpio)
pdata->cfg_gpio(pdev, pdata->max_width);
host->hw_name = "samsung-hsmmc";
host->ops = &sdhci_s3c_ops;
host->quirks = 0;
host->irq = irq;
/* Setup quirks for the controller */
/* Currently with ADMA enabled we are getting some length
* interrupts that are not being dealt with, do disable
* ADMA until this is sorted out. */
host->quirks |= SDHCI_QUIRK_BROKEN_ADMA;
host->quirks |= SDHCI_QUIRK_32BIT_ADMA_SIZE;
#ifndef CONFIG_MMC_SDHCI_S3C_DMA
/* we currently see overruns on errors, so disable the SDMA
* support as well. */
host->quirks |= SDHCI_QUIRK_BROKEN_DMA;
/* PIO currently has problems with multi-block IO */
host->quirks |= SDHCI_QUIRK_NO_MULTIBLOCK;
#endif /* CONFIG_MMC_SDHCI_S3C_DMA */
/* It seems we do not get an DATA transfer complete on non-busy
* transfers, not sure if this is a problem with this specific
* SDHCI block, or a missing configuration that needs to be set. */
host->quirks |= SDHCI_QUIRK_NO_BUSY_IRQ;
host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR |
SDHCI_QUIRK_32BIT_DMA_SIZE);
ret = sdhci_add_host(host);
if (ret) {
dev_err(dev, "sdhci_add_host() failed\n");
goto err_add_host;
}
return 0;
err_add_host:
release_resource(sc->ioarea);
kfree(sc->ioarea);
err_req_regs:
for (ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
clk_disable(sc->clk_bus[ptr]);
clk_put(sc->clk_bus[ptr]);
}
err_no_busclks:
clk_disable(sc->clk_io);
clk_put(sc->clk_io);
err_io_clk:
sdhci_free_host(host);
return ret;
}
static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
{
return 0;
}
#ifdef CONFIG_PM
static int sdhci_s3c_suspend(struct platform_device *dev, pm_message_t pm)
{
struct sdhci_host *host = platform_get_drvdata(dev);
sdhci_suspend_host(host, pm);
return 0;
}
static int sdhci_s3c_resume(struct platform_device *dev)
{
struct sdhci_host *host = platform_get_drvdata(dev);
sdhci_resume_host(host);
return 0;
}
#else
#define sdhci_s3c_suspend NULL
#define sdhci_s3c_resume NULL
#endif
static struct platform_driver sdhci_s3c_driver = {
.probe = sdhci_s3c_probe,
.remove = __devexit_p(sdhci_s3c_remove),
.suspend = sdhci_s3c_suspend,
.resume = sdhci_s3c_resume,
.driver = {
.owner = THIS_MODULE,
.name = "s3c-sdhci",
},
};
static int __init sdhci_s3c_init(void)
{
return platform_driver_register(&sdhci_s3c_driver);
}
static void __exit sdhci_s3c_exit(void)
{
platform_driver_unregister(&sdhci_s3c_driver);
}
module_init(sdhci_s3c_init);
module_exit(sdhci_s3c_exit);
MODULE_DESCRIPTION("Samsung SDHCI (HSMMC) glue");
MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:s3c-sdhci");
