[PATCH 3/3] MMC: sdhci-dove: allow GPIOs to be used for card detection on Dove

Russell King
2012-11-22T23:59:17Z

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>
---
drivers/mmc/host/sdhci-dove.c | 73 +++++++++++++++++++++++++++++++++++++---
1 files changed, 67 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/host/sdhci-dove.c b/drivers/mmc/host/sdhci-dove.c
index 4af64f3..e621448 100644
--- a/drivers/mmc/host/sdhci-dove.c
+++ b/drivers/mmc/host/sdhci-dove.c
@@ -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);

--
1.7.4.4