[PATCH 1/2] sdhci/tegra: Add Device Tree probing support

Stephen Warren
2011-08-23T18:16:08Z

From: Grant Likely <grant.likely@secretlab.ca>

Add hooks to read gpio configuration out of the device tree node.

[grant.likely: Rewrite of original patch from John Bonesio]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
[swarren: Fixed tegra_sdhci_get_ro() to retrieve pdata correctly]
[swarren: Reworked to avoid #ifdef CONFIG_OF]
[swarren: Reworked binding based on fsl-imx-esdhc.txt]
[swarren: Documented binding]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
Theoretically, these two patches should be merged in order in one place,
since the 2nd logically depends on the first. However, it's really just
a documentation dependency, so I think it's fine to merge them into the
MMC and DT trees separately and let them meet in linux-next.

.../devicetree/bindings/mmc/nvidia-sdhci.txt | 25 ++++++++++
drivers/mmc/host/sdhci-tegra.c | 51 +++++++++++++++----
2 files changed, 65 insertions(+), 11 deletions(-)
create mode 100644 Documentation/devicetree/bindings/mmc/nvidia-sdhci.txt

diff --git a/Documentation/devicetree/bindings/mmc/nvidia-sdhci.txt b/Documentation/devicetree/bindings/mmc/nvidia-sdhci.txt
new file mode 100644
index 0000000..c87f667
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/nvidia-sdhci.txt
@@ -0,0 +1,25 @@
+* NVIDIA Tegra Secure Digital Host Controller
+
+This controller on Tegra family SoCs provides an interface for MMC, SD,
+and SDIO types of memory cards.
+
+Required properties:
+- compatible : Should be "nvidia,<chip>-sdhci"
+- reg : Should contain eSDHC registers location and length
+- interrupts : Should contain eSDHC interrupt
+
+Optional properties:
+- cd-gpios : Specify GPIOs for card detection
+- wp-gpios : Specify GPIOs for write protection
+- power-gpios : Specify GPIOs for power control
+
+Example:
+
+sdhci@c8000200 {
+ compatible = "nvidia,tegra20-sdhci";
+ reg = <0xc8000200 0x200>;
+ interrupts = <47>;
+ cd-gpios = <&gpio 69 0>; /* gpio PI5 */
+ wp-gpios = <&gpio 57 0>; /* gpio PH1 */
+ power-gpios = <&gpio 155 0>; /* gpio PT3 */
+};
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index a5a9a97..9ab18d6 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -17,6 +17,7 @@
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/io.h>
+#include <linux/of_gpio.h>
#include <linux/gpio.h>
#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
@@ -74,10 +75,8 @@ static void tegra_sdhci_writel(struct sdhci_host *host, u32 val, int reg)

static unsigned int tegra_sdhci_get_ro(struct sdhci_host *sdhci)
{
- struct platform_device *pdev = to_platform_device(mmc_dev(sdhci->mmc));
- struct tegra_sdhci_platform_data *plat;
-
- plat = pdev->dev.platform_data;
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(sdhci);
+ struct tegra_sdhci_platform_data *plat = pltfm_host->priv;

if (!gpio_is_valid(plat->wp_gpio))
return -1;
@@ -95,12 +94,10 @@ static irqreturn_t carddetect_irq(int irq, void *data)

static int tegra_sdhci_8bit(struct sdhci_host *host, int bus_width)
{
- struct platform_device *pdev = to_platform_device(mmc_dev(host->mmc));
- struct tegra_sdhci_platform_data *plat;
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct tegra_sdhci_platform_data *plat = pltfm_host->priv;
u32 ctrl;

- plat = pdev->dev.platform_data;
-
ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
if (plat->is_8bit && bus_width == MMC_BUS_WIDTH_8) {
ctrl &= ~SDHCI_CTRL_4BITBUS;
@@ -132,6 +129,34 @@ static struct sdhci_pltfm_data sdhci_tegra_pdata = {
.ops = &tegra_sdhci_ops,
};

+static const struct of_device_id sdhci_tegra_dt_match[] __devinitdata = {
+ { .compatible = "nvidia,tegra20-sdhci", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, sdhci_dt_ids);
+
+static struct tegra_sdhci_platform_data * __devinit sdhci_tegra_dt_parse_pdata(
+ struct platform_device *pdev)
+{
+ struct tegra_sdhci_platform_data *plat;
+ struct device_node *np = pdev->dev.of_node;
+
+ if (!np)
+ return NULL;
+
+ plat = devm_kzalloc(&pdev->dev, sizeof(*plat), GFP_KERNEL);
+ if (!plat) {
+ dev_err(&pdev->dev, "Can't allocate platform data\n");
+ return NULL;
+ }
+
+ plat->cd_gpio = of_get_named_gpio(np, "cd-gpios", 0);
+ plat->wp_gpio = of_get_named_gpio(np, "wp-gpios", 0);
+ plat->power_gpio = of_get_named_gpio(np, "power-gpios", 0);
+
+ return plat;
+}
+
static int __devinit sdhci_tegra_probe(struct platform_device *pdev)
{
struct sdhci_pltfm_host *pltfm_host;
@@ -148,12 +173,17 @@ static int __devinit sdhci_tegra_probe(struct platform_device *pdev)

plat = pdev->dev.platform_data;

+ if (plat == NULL)
+ plat = sdhci_tegra_dt_parse_pdata(pdev);
+
if (plat == NULL) {
dev_err(mmc_dev(host->mmc), "missing platform data\n");
rc = -ENXIO;
goto err_no_plat;
}

+ pltfm_host->priv = plat;
+
if (gpio_is_valid(plat->power_gpio)) {
rc = gpio_request(plat->power_gpio, "sdhci_power");
if (rc) {
@@ -248,13 +278,11 @@ static int __devexit sdhci_tegra_remove(struct platform_device *pdev)
{
struct sdhci_host *host = platform_get_drvdata(pdev);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
- struct tegra_sdhci_platform_data *plat;
+ struct tegra_sdhci_platform_data *plat = pltfm_host->priv;
int dead = (readl(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);

sdhci_remove_host(host, dead);

- plat = pdev->dev.platform_data;
-
if (gpio_is_valid(plat->wp_gpio)) {
tegra_gpio_disable(plat->wp_gpio);
gpio_free(plat->wp_gpio);
@@ -283,6 +311,7 @@ static struct platform_driver sdhci_tegra_driver = {
.driver = {
.name = "sdhci-tegra",
.owner = THIS_MODULE,
+ .of_match_table = sdhci_tegra_dt_match,
},
.probe = sdhci_tegra_probe,
.remove = __devexit_p(sdhci_tegra_remove),
--
1.7.0.4