- 根目录:
- drivers
- mmc
- host
- sdhci-s3c.c
/* 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/slab.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/gpio.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;
int ext_cd_irq;
int ext_cd_gpio;
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;
}
/**
* 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;
/*
* Clock divider's step is different as 1 from that of host controller
* when 'clk_type' is S3C_SDHCI_CLK_DIV_EXTERNAL.
*/
if (ourhost->pdata->clk_type) {
rate = clk_round_rate(clksrc, wanted);
return wanted - rate;
}
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);
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);
}
}
/**
* sdhci_s3c_get_min_clock - callback to get minimal supported clock value
* @host: The SDHCI host being queried
*
* To init mmc host properly a minimal clock value is needed. For high system
* bus clock's values the standard formula gives values out of allowed range.
* The clock still can be set to lower values, if clock source other then
* system bus is selected.
*/
static unsigned int sdhci_s3c_get_min_clock(struct sdhci_host *host)
{
struct sdhci_s3c *ourhost = to_s3c(host);
unsigned int delta, min = UINT_MAX;
int src;
for (src = 0; src < MAX_BUS_CLK; src++) {
delta = sdhci_s3c_consider_clock(ourhost, src, 0);
if (delta == UINT_MAX)
continue;
/* delta is a negative value in this case */
if (-delta < min)
min = -delta;
}
return min;
}
/* sdhci_cmu_get_max_clk - callback to get maximum clock frequency.*/
static unsigned int sdhci_cmu_get_max_clock(struct sdhci_host *host)
{
struct sdhci_s3c *ourhost = to_s3c(host);
return clk_round_rate(ourhost->clk_bus[ourhost->cur_clk], UINT_MAX);
}
/* sdhci_cmu_get_min_clock - callback to get minimal supported clock value. */
static unsigned int sdhci_cmu_get_min_clock(struct sdhci_host *host)
{
struct sdhci_s3c *ourhost = to_s3c(host);
/*
* initial clock can be in the frequency range of
* 100KHz-400KHz, so we set it as max value.
*/
return clk_round_rate(ourhost->clk_bus[ourhost->cur_clk], 400000);
}
/* sdhci_cmu_set_clock - callback on clock change.*/
static void sdhci_cmu_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct sdhci_s3c *ourhost = to_s3c(host);
/* don't bother if the clock is going off */
if (clock == 0)
return;
sdhci_s3c_set_clock(host, clock);
clk_set_rate(ourhost->clk_bus[ourhost->cur_clk], clock);
host->clock = clock;
}
/**
* sdhci_s3c_platform_8bit_width - support 8bit buswidth
* @host: The SDHCI host being queried
* @width: MMC_BUS_WIDTH_ macro for the bus width being requested
*
* We have 8-bit width support but is not a v3 controller.
* So we add platform_8bit_width() and support 8bit width.
*/
static int sdhci_s3c_platform_8bit_width(struct sdhci_host *host, int width)
{
u8 ctrl;
ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
switch (width) {
case MMC_BUS_WIDTH_8:
ctrl |= SDHCI_CTRL_8BITBUS;
ctrl &= ~SDHCI_CTRL_4BITBUS;
break;
case MMC_BUS_WIDTH_4:
ctrl |= SDHCI_CTRL_4BITBUS;
ctrl &= ~SDHCI_CTRL_8BITBUS;
break;
default:
break;
}
sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
return 0;
}
static struct sdhci_ops sdhci_s3c_ops = {
.get_max_clock = sdhci_s3c_get_max_clk,
.set_clock = sdhci_s3c_set_clock,
.get_min_clock = sdhci_s3c_get_min_clock,
.platform_8bit_width = sdhci_s3c_platform_8bit_width,
};
static void sdhci_s3c_notify_change(struct platform_device *dev, int state)
{
struct sdhci_host *host = platform_get_drvdata(dev);
unsigned long flags;
if (host) {
spin_lock_irqsave(&host->lock, flags);
if (state) {
dev_dbg(&dev->dev, "card inserted.\n");
host->flags &= ~SDHCI_DEVICE_DEAD;
host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
} else {
dev_dbg(&dev->dev, "card removed.\n");
host->flags |= SDHCI_DEVICE_DEAD;
host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
}
tasklet_schedule(&host->card_tasklet);
spin_unlock_irqrestore(&host->lock, flags);
}
}
static irqreturn_t sdhci_s3c_gpio_card_detect_thread(int irq, void *dev_id)
{
struct sdhci_s3c *sc = dev_id;
int status = gpio_get_value(sc->ext_cd_gpio);
if (sc->pdata->ext_cd_gpio_invert)
status = !status;
sdhci_s3c_notify_change(sc->pdev, status);
return IRQ_HANDLED;
}
static void sdhci_s3c_setup_card_detect_gpio(struct sdhci_s3c *sc)
{
struct s3c_sdhci_platdata *pdata = sc->pdata;
struct device *dev = &sc->pdev->dev;
if (gpio_request(pdata->ext_cd_gpio, "SDHCI EXT CD") == 0) {
sc->ext_cd_gpio = pdata->ext_cd_gpio;
sc->ext_cd_irq = gpio_to_irq(pdata->ext_cd_gpio);
if (sc->ext_cd_irq &&
request_threaded_irq(sc->ext_cd_irq, NULL,
sdhci_s3c_gpio_card_detect_thread,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
dev_name(dev), sc) == 0) {
int status = gpio_get_value(sc->ext_cd_gpio);
if (pdata->ext_cd_gpio_invert)
status = !status;
sdhci_s3c_notify_change(sc->pdev, status);
} else {
dev_warn(dev, "cannot request irq for card detect\n");
sc->ext_cd_irq = 0;
}
} else {
dev_err(dev, "cannot request gpio for card detect\n");
}
}
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;
sc->ext_cd_gpio = -1; /* invalid gpio number */
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;
/*
* save current clock index to know which clock bus
* is used later in overriding functions.
*/
sc->cur_clk = ptr;
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 */
host->quirks |= SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC;
host->quirks |= SDHCI_QUIRK_NO_HISPD_BIT;
#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;
#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;
/* This host supports the Auto CMD12 */
host->quirks |= SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12;
if (pdata->cd_type == S3C_SDHCI_CD_NONE ||
pdata->cd_type == S3C_SDHCI_CD_PERMANENT)
host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
if (pdata->cd_type == S3C_SDHCI_CD_PERMANENT)
host->mmc->caps = MMC_CAP_NONREMOVABLE;
if (pdata->host_caps)
host->mmc->caps |= pdata->host_caps;
host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR |
SDHCI_QUIRK_32BIT_DMA_SIZE);
/* HSMMC on Samsung SoCs uses SDCLK as timeout clock */
host->quirks |= SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK;
/*
* If controller does not have internal clock divider,
* we can use overriding functions instead of default.
*/
if (pdata->clk_type) {
sdhci_s3c_ops.set_clock = sdhci_cmu_set_clock;
sdhci_s3c_ops.get_min_clock = sdhci_cmu_get_min_clock;
sdhci_s3c_ops.get_max_clock = sdhci_cmu_get_max_clock;
}
/* It supports additional host capabilities if needed */
if (pdata->host_caps)
host->mmc->caps |= pdata->host_caps;
ret = sdhci_add_host(host);
if (ret) {
dev_err(dev, "sdhci_add_host() failed\n");
goto err_add_host;
}
/* The following two methods of card detection might call
sdhci_s3c_notify_change() immediately, so they can be called
only after sdhci_add_host(). Setup errors are ignored. */
if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_init)
pdata->ext_cd_init(&sdhci_s3c_notify_change);
if (pdata->cd_type == S3C_SDHCI_CD_GPIO &&
gpio_is_valid(pdata->ext_cd_gpio))
sdhci_s3c_setup_card_detect_gpio(sc);
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)
{
struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
struct sdhci_host *host = platform_get_drvdata(pdev);
struct sdhci_s3c *sc = sdhci_priv(host);
int ptr;
if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_cleanup)
pdata->ext_cd_cleanup(&sdhci_s3c_notify_change);
if (sc->ext_cd_irq)
free_irq(sc->ext_cd_irq, sc);
if (gpio_is_valid(sc->ext_cd_gpio))
gpio_free(sc->ext_cd_gpio);
sdhci_remove_host(host, 1);
for (ptr = 0; ptr < 3; ptr++) {
if (sc->clk_bus[ptr]) {
clk_disable(sc->clk_bus[ptr]);
clk_put(sc->clk_bus[ptr]);
}
}
clk_disable(sc->clk_io);
clk_put(sc->clk_io);
iounmap(host->ioaddr);
release_resource(sc->ioarea);
kfree(sc->ioarea);
sdhci_free_host(host);
platform_set_drvdata(pdev, NULL);
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");