mmc: sdhci-dove: allow GPIOs to be used for card detection on Dove

This commit taken from Rabeeh's Cubox kernel and re-worked for DT;
Sebastian Hasselbrath is believed to be the original author.

Some Cuboxes require a GPIO for card detection; this implements the
optional GPIO support for card detection.  This GPIO is logic 0 for
card inserted.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Russell King 2012-11-22 23:55:51 +00:00 committed by Chris Ball
parent c430689f3f
commit f8ec589b86

View File

@ -19,20 +19,30 @@
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/mmc/host.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include "sdhci-pltfm.h"
struct sdhci_dove_priv {
struct clk *clk;
int gpio_cd;
};
static irqreturn_t sdhci_dove_carddetect_irq(int irq, void *data)
{
struct sdhci_host *host = data;
tasklet_schedule(&host->card_tasklet);
return IRQ_HANDLED;
}
static u16 sdhci_dove_readw(struct sdhci_host *host, int reg)
{
u16 ret;
@ -50,16 +60,25 @@ static u16 sdhci_dove_readw(struct sdhci_host *host, int reg)
static u32 sdhci_dove_readl(struct sdhci_host *host, int reg)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct sdhci_dove_priv *priv = pltfm_host->priv;
u32 ret;
ret = readl(host->ioaddr + reg);
switch (reg) {
case SDHCI_CAPABILITIES:
ret = readl(host->ioaddr + reg);
/* Mask the support for 3.0V */
ret &= ~SDHCI_CAN_VDD_300;
break;
default:
ret = readl(host->ioaddr + reg);
case SDHCI_PRESENT_STATE:
if (gpio_is_valid(priv->gpio_cd)) {
if (gpio_get_value(priv->gpio_cd) == 0)
ret |= SDHCI_CARD_PRESENT;
else
ret &= ~SDHCI_CARD_PRESENT;
}
break;
}
return ret;
}
@ -94,6 +113,23 @@ static int __devinit sdhci_dove_probe(struct platform_device *pdev)
priv->clk = devm_clk_get(&pdev->dev, NULL);
if (pdev->dev.of_node) {
priv->gpio_cd = of_get_named_gpio(pdev->dev.of_node,
"cd-gpios", 0);
} else {
priv->gpio_cd = -EINVAL;
}
if (gpio_is_valid(priv->gpio_cd)) {
ret = gpio_request(priv->gpio_cd, "sdhci-cd");
if (ret) {
dev_err(&pdev->dev, "card detect gpio request failed: %d\n",
ret);
return ret;
}
gpio_direction_input(priv->gpio_cd);
}
host = sdhci_pltfm_init(pdev, &sdhci_dove_pdata);
if (IS_ERR(host)) {
ret = PTR_ERR(host);
@ -112,13 +148,33 @@ static int __devinit sdhci_dove_probe(struct platform_device *pdev)
if (ret)
goto err_sdhci_add;
/*
* We must request the IRQ after sdhci_add_host(), as the tasklet only
* gets setup in sdhci_add_host() and we oops.
*/
if (gpio_is_valid(priv->gpio_cd)) {
ret = request_irq(gpio_to_irq(priv->gpio_cd),
sdhci_dove_carddetect_irq,
IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
mmc_hostname(host->mmc), host);
if (ret) {
dev_err(&pdev->dev, "card detect irq request failed: %d\n",
ret);
goto err_request_irq;
}
}
return 0;
err_request_irq:
sdhci_remove_host(host, 0);
err_sdhci_add:
if (!IS_ERR(priv->clk))
clk_disable_unprepare(priv->clk);
sdhci_pltfm_free(pdev);
err_sdhci_pltfm_init:
if (gpio_is_valid(priv->gpio_cd))
gpio_free(priv->gpio_cd);
return ret;
}
@ -130,6 +186,11 @@ static int __devexit sdhci_dove_remove(struct platform_device *pdev)
sdhci_pltfm_unregister(pdev);
if (gpio_is_valid(priv->gpio_cd)) {
free_irq(gpio_to_irq(priv->gpio_cd), host);
gpio_free(priv->gpio_cd);
}
if (!IS_ERR(priv->clk))
clk_disable_unprepare(priv->clk);