[PATCH 3/3] mmc: sdhci-s3c: Add device tree support
Thomas Abraham
thomas.abraham at linaro.org
Wed Oct 5 06:13:01 EDT 2011
Add device tree based discovery support for Samsung's sdhci controller
Cc: Ben Dooks <ben-linux at fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
---
.../devicetree/bindings/mmc/samsung-sdhci.txt | 75 ++++++++++
drivers/mmc/host/sdhci-s3c.c | 150 +++++++++++++++++++-
2 files changed, 219 insertions(+), 6 deletions(-)
create mode 100644 Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
diff --git a/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
new file mode 100644
index 0000000..dc94d24
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
@@ -0,0 +1,75 @@
+* Samsung's SDHCI Controller device tree bindings
+
+Samsung's SDHCI controller is used as a connectivity interface with external
+MMC, SD and eMMC storage mediums.
+
+Required SoC Specific Properties:
+- compatible: should be one of the following
+ - "samsung,s3c6410-sdhci": For controllers compatible with s3c6410 sdhci
+ controller.
+ - "samsung,exynos4-sdhci": For controller compatible with Exynos4 sdhci
+ controller.
+
+- reg: physical base address of the controller and length of memory mapped
+ region.
+
+- interrupts: The interrupt number to the cpu. The interrupt specifier format
+ depends on the interrupt controller.
+
+
+Required Board Specific Properties:
+- gpios: Should specify the gpios used for clock, command and data lines. The
+ gpio specifier format depends on the gpio controller. Note: There is no
+ particular order in which the gpio's have to be listed.
+
+
+Optional Board Specific Properties:
+- samsung,sdhci-bus-width: Number of data lines connected to the controller.
+ Note: This excludes the clock,command and card detect lines. If this property
+ is not specified, default value is 1.
+
+- samsung,cd-gpio-invert: If 'samsung,sdhci-cd-gpio' card detect method is
+ selected, this property can be optionally specified to invert the value of
+ external card detect gpio line.
+
+- One of the following properties for card detect type.
+ - samsung,sdhci-cd-internal: Card detect line from the card slot is
+ connected to the card detect pad of the sdhci controller. A gpio is
+ used for this connection (with possible pin function settings).
+ - samsung,sdhci-cd-gpio: A gpio line (with possible pin function settings)
+ is used a card detect line. This gpio line is not connected to card detect
+ pad of the sdhci controller.
+ - samsung,sdhci-cd-none: There is no card detect line. Polling is used to
+ detect the presence of the card. (DEFAULT, if no card detect property
+ is specified).
+ - samsung,sdhci-cd-permanent: There is no card detect line. The card is
+ permanently connected to the sdhci controller.
+
+- gpio-cd: The gpio to be used as card detect line for
+ 'samsung,sdhci-cd-internal' or 'samsung,sdhci-cd-gpio' card detection method.
+ The gpio specifier format depends on the gpio controller.
+
+- One or more of the linux specific mmc host bindings.
+ See Documentation/devicetree/bindings/mmc/linux-mmc-host.txt for all the
+ linux mmc host controller specific bindings.
+
+Example:
+ sdhci at 12530000 {
+ compatible = "samsung,exynos4-sdhci";
+ reg = <0x12530000 0x100>;
+ interrupts = <139>;
+ samsung,sdhci-bus-width = <4>;
+ linux,mmc_cap_4_bit_data;
+ samsung,sdhci-cd-internal;
+ gpio-cd = <&gpk2 2 2 3 3>;
+ gpios = <&gpk2 0 2 0 3>, /* clock line */
+ <&gpk2 1 2 0 3>, /* command line */
+ <&gpk2 3 2 3 3>, /* data line 0 */
+ <&gpk2 4 2 3 3>, /* data line 1 */
+ <&gpk2 5 2 3 3>, /* data line 2 */
+ <&gpk2 6 2 3 3>; /* data line 3 */
+ };
+
+ Note: This example shows both SoC specific and board specific properties
+ in a single device node. The properties can be actually be seperated
+ into SoC specific node and board specific node.
diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index 8280af0..047c404 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -20,6 +20,8 @@
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
#include <linux/mmc/host.h>
@@ -29,6 +31,8 @@
#include "sdhci.h"
#define MAX_BUS_CLK (4)
+/* Number of gpio's used is max data bus width + command and clock lines */
+#define NUM_GPIOS(x) (x + 2)
/**
* struct sdhci_s3c - S3C SDHCI instance
@@ -48,6 +52,7 @@ struct sdhci_s3c {
unsigned int cur_clk;
int ext_cd_irq;
int ext_cd_gpio;
+ int *gpios;
struct clk *clk_io;
struct clk *clk_bus[MAX_BUS_CLK];
@@ -415,9 +420,110 @@ static void sdhci_s3c_setup_card_detect_gpio(struct sdhci_s3c *sc)
}
}
+#ifdef CONFIG_OF
+static int __devinit sdhci_s3c_parse_dt(struct device *dev,
+ struct sdhci_host *host, struct s3c_sdhci_platdata *pdata)
+{
+ struct device_node *node = dev->of_node;
+ struct sdhci_s3c *ourhost = to_s3c(host);
+ u32 max_width;
+ int gpio, cnt, ret;
+
+ /* if the bus-width property is not specified, assume width as 1 */
+ if (of_property_read_u32(node, "samsung,sdhci-bus-width",
+ &max_width))
+ max_width = 1;
+ pdata->max_width = max_width;
+
+ ourhost->gpios = devm_kzalloc(dev, NUM_GPIOS(pdata->max_width) *
+ sizeof(int), GFP_KERNEL);
+ if (!ourhost->gpios)
+ return -ENOMEM;
+
+ mmc_of_parse_host_caps(node, (unsigned long *)&pdata->host_caps);
+
+ /* get the card detection method */
+ if (of_get_property(node, "samsung,sdhci-cd-internal", NULL))
+ pdata->cd_type = S3C_SDHCI_CD_INTERNAL;
+ else if (of_get_property(node, "samsung,sdhci-cd-gpio", NULL))
+ pdata->cd_type = S3C_SDHCI_CD_GPIO;
+ else if (of_get_property(node, "samsung,sdhci-cd-none", NULL))
+ pdata->cd_type = S3C_SDHCI_CD_NONE;
+ else if (of_get_property(node, "samsung,sdhci-cd-permanent", NULL))
+ pdata->cd_type = S3C_SDHCI_CD_PERMANENT;
+ else
+ pdata->cd_type = S3C_SDHCI_CD_NONE;
+
+ /* get the gpio used for card detection */
+ if (pdata->cd_type == S3C_SDHCI_CD_GPIO || S3C_SDHCI_CD_INTERNAL) {
+ gpio = of_get_named_gpio(node, "gpio-cd", 0);
+ if (!gpio_is_valid(gpio)) {
+ dev_err(dev, "invalid card detect gpio specified\n");
+ return -EINVAL;
+ }
+ }
+
+ if (pdata->cd_type == S3C_SDHCI_CD_GPIO) {
+ pdata->ext_cd_gpio = gpio;
+ ourhost->ext_cd_gpio = -1; /* invalid gpio number */
+ if (of_get_property(node, "samsung,cd-gpio-invert", NULL))
+ pdata->ext_cd_gpio_invert = 1;
+ } else if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL) {
+ ret = gpio_request(gpio, "sdhci-cd");
+ if (ret) {
+ dev_err(dev, "card detect gpio request failed\n");
+ return -EINVAL;
+ }
+ ourhost->ext_cd_gpio = gpio;
+ }
+
+ /* get the gpios for command, clock and data lines */
+ for (cnt = 0; cnt < NUM_GPIOS(pdata->max_width); cnt++) {
+ gpio = of_get_gpio(node, cnt);
+ if (!gpio_is_valid(gpio)) {
+ dev_err(dev, "invalid gpio[%d]\n", cnt);
+ goto err_free_dt_cd_gpio;
+ }
+ ourhost->gpios[cnt] = gpio;
+ }
+
+ for (cnt = 0; cnt < NUM_GPIOS(pdata->max_width); cnt++) {
+ ret = gpio_request(ourhost->gpios[cnt], "sdhci-gpio");
+ if (ret) {
+ dev_err(dev, "gpio[%d] request failed\n", cnt);
+ goto err_free_dt_gpios;
+ }
+ }
+
+ return 0;
+
+ err_free_dt_gpios:
+ while (--cnt >= 0)
+ gpio_free(ourhost->gpios[cnt]);
+ err_free_dt_cd_gpio:
+ if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL)
+ gpio_free(ourhost->ext_cd_gpio);
+ return -EINVAL;
+}
+#else
+static int __devinit sdhci_s3c_parse_dt(struct device *dev,
+ struct sdhci_host *host, struct s3c_sdhci_platdata *pdata)
+{
+}
+#endif
+
+static const struct of_device_id sdhci_s3c_dt_match[];
+
static inline struct sdhci_s3c_drv_data *sdhci_s3c_get_driver_data(
struct platform_device *pdev)
{
+#if CONFIG_OF
+ if (pdev->dev.of_node) {
+ const struct of_device_id *match;
+ match = of_match_node(sdhci_s3c_dt_match, pdev->dev.of_node);
+ return (struct sdhci_s3c_drv_data *)match->data;
+ }
+#endif
return (struct sdhci_s3c_drv_data *)
platform_get_device_id(pdev)->driver_data;
}
@@ -432,7 +538,7 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
struct resource *res;
int ret, irq, ptr, clks;
- if (!pdev->dev.platform_data) {
+ if (!pdev->dev.platform_data && !pdev->dev.of_node) {
dev_err(dev, "no device data specified\n");
return -ENOENT;
}
@@ -454,21 +560,28 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
dev_err(dev, "sdhci_alloc_host() failed\n");
return PTR_ERR(host);
}
+ sc = sdhci_priv(host);
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata) {
ret = -ENOMEM;
- goto err_io_clk;
+ goto err_pdata;
+ }
+
+ if (pdev->dev.of_node) {
+ ret = sdhci_s3c_parse_dt(&pdev->dev, host, pdata);
+ if (ret)
+ goto err_pdata;
+ } else {
+ memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata));
+ sc->ext_cd_gpio = -1; /* invalid gpio number */
}
- memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata));
drv_data = sdhci_s3c_get_driver_data(pdev);
- 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);
@@ -625,6 +738,12 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
clk_put(sc->clk_io);
err_io_clk:
+ for (ptr = 0; ptr < NUM_GPIOS(sc->pdata->max_width); ptr++)
+ gpio_free(sc->gpios[ptr]);
+ if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL)
+ gpio_free(sc->ext_cd_gpio);
+
+ err_pdata:
sdhci_free_host(host);
return ret;
@@ -632,9 +751,9 @@ 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);
+ struct s3c_sdhci_platdata *pdata = sc->pdata;
int ptr;
if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_cleanup)
@@ -661,6 +780,11 @@ static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
release_resource(sc->ioarea);
kfree(sc->ioarea);
+ if (pdev->dev.of_node) {
+ for (ptr = 0; ptr < NUM_GPIOS(sc->pdata->max_width); ptr++)
+ gpio_free(sc->gpios[ptr]);
+ }
+
sdhci_free_host(host);
platform_set_drvdata(pdev, NULL);
@@ -706,9 +830,22 @@ static struct platform_device_id sdhci_s3c_driver_ids[] = {
.name = "exynos4-sdhci",
.driver_data = EXYNOS4_SDHCI_DRV_DATA,
},
+ {},
};
MODULE_DEVICE_TABLE(platform, sdhci_s3c_driver_ids);
+#ifdef CONFIG_OF
+static const struct of_device_id sdhci_s3c_dt_match[] = {
+ { .compatible = "samsung,s3c6410-sdhci", },
+ { .compatible = "samsung,exynos4-sdhci",
+ .data = &exynos4_sdhci_drv_data },
+ {},
+};
+MODULE_DEVICE_TABLE(of, sdhci_s3c_dt_match);
+#else
+#define sdhci_s3c_dt_match NULL
+#endif
+
static struct platform_driver sdhci_s3c_driver = {
.probe = sdhci_s3c_probe,
.remove = __devexit_p(sdhci_s3c_remove),
@@ -718,6 +855,7 @@ static struct platform_driver sdhci_s3c_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "s3c-sdhci",
+ .of_match_table = sdhci_s3c_dt_match,
},
};
--
1.6.6.rc2
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