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authorMarek Szyprowski <m.szyprowski@samsung.com>2010-08-10 18:01:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-11 08:59:05 -0700
commit17866e14f3a4f219e94f1374ece7226479418ff8 (patch)
tree4e1a618f9dbcdc982bac4289eec30a87c764c33c /drivers/mmc/host/sdhci-s3c.c
parenta1d5646005af1247d6ae78434bb4db15b07a07b2 (diff)
sdhci-s3c: add support for new card detection methods
On some Samsung SoCs not all SDHCI controllers have card detect (CD) line. For some embedded designs it is not even needed, because ususally the device (like SDIO flash memory or wifi controller) is permanently wired to the controller. There are also systems which have a card detect line connected to some of the external interrupt lines or the presence of the card depends on some other actions (like enabling a power regulator). This patch adds support for all these cases. The following card detection methods are possible: 1. internal sdhci host card detect line 2. external event 3. external gpio interrupt 4. no card detect line, controller will poll for the card 5. no card detect line, card is permanently wired to the controller (once detected host won't poll it any more) By default, all existing code would use method #1, what is compatible with the previous version of the driver. In case of external event, two callbacks must be provided in platdata: ext_cd_init and ext_cd_cleanup. Both of them get a callback to a function that notifies the s3c-sdhci host contoller as their argument. That callback function should be called from the even dispatcher to let host notice the card insertion/removal. In case of external gpio interrupt, a gpio pin number must be provided in platdata (ext_cd_gpio parameter), as well as the information about the polarity of that gpio pin (ext_cd_gpio_invert). By default (ext_cd_gpio_invert == 0) gpio value 0 means 'card has been removed', but this can be changed to 'card has been removed' when ext_cd_gpio_invert == 1. This patch adds all required changes to sdhci-s3c driver. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: <linux-mmc@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/mmc/host/sdhci-s3c.c')
-rw-r--r--drivers/mmc/host/sdhci-s3c.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index f0b819d98a8..0a7f2614c6f 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -18,6 +18,7 @@
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/io.h>
+#include <linux/gpio.h>
#include <linux/mmc/host.h>
@@ -44,6 +45,8 @@ struct sdhci_s3c {
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];
@@ -235,6 +238,61 @@ static struct sdhci_ops sdhci_s3c_ops = {
.get_min_clock = sdhci_s3c_get_min_clock,
};
+static void sdhci_s3c_notify_change(struct platform_device *dev, int state)
+{
+ struct sdhci_host *host = platform_get_drvdata(dev);
+ if (host) {
+ mutex_lock(&host->lock);
+ 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;
+ }
+ sdhci_card_detect(host);
+ mutex_unlock(&host->lock);
+ }
+}
+
+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;
@@ -272,6 +330,7 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
sc->host = host;
sc->pdev = pdev;
sc->pdata = pdata;
+ sc->ext_cd_gpio = -1; /* invalid gpio number */
platform_set_drvdata(pdev, host);
@@ -353,6 +412,13 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
* SDHCI block, or a missing configuration that needs to be set. */
host->quirks |= SDHCI_QUIRK_NO_BUSY_IRQ;
+ 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;
+
host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR |
SDHCI_QUIRK_32BIT_DMA_SIZE);
@@ -365,6 +431,15 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
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:
@@ -389,10 +464,20 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
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++) {