[PATCH v2 3/3] mmc: sdhci-esdhc-imx: add device tree probe support
Grant Likely
grant.likely at secretlab.ca
Tue Jul 5 13:54:34 EDT 2011
On Tue, Jul 5, 2011 at 9:26 AM, Shawn Guo <shawn.guo at linaro.org> wrote:
> The patch adds device tree probe support for sdhci-esdhc-imx driver.
>
> Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
> Cc: Wolfram Sang <w.sang at pengutronix.de>
> Cc: Chris Ball <cjb at laptop.org>
> Cc: Grant Likely <grant.likely at secretlab.ca>
> ---
> .../devicetree/bindings/mmc/fsl-imx-esdhc.txt | 40 ++++++++
> drivers/mmc/host/sdhci-esdhc-imx.c | 102 +++++++++++++++++++-
> 2 files changed, 137 insertions(+), 5 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt
>
> diff --git a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt
> new file mode 100644
> index 0000000..351d239
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt
> @@ -0,0 +1,40 @@
> +* Freescale Enhanced Secure Digital Host Controller (eSDHC) for i.MX
> +
> +The Enhanced Secure Digital Host Controller on Freescale i.MX family
> +provides an interface for MMC, SD, and SDIO types of memory cards.
> +
> +Required properties:
> +- compatible : Should be "fsl,<chip>-esdhc"
> +- reg : Should contain eSDHC registers location and length
> +- interrupts : Should contain eSDHC interrupt
> +- cd-type : String, card detection (CD) method. Supported values are:
> + "none" : No CD
> + "controller" : Uses eSDHC controller internal CD signal
> + "gpio" : Uses GPIO pin for CD
> + "permanent" : No CD because card is permanently wired to host
> +- wp-type : String, write protection (WP) method. Supported values are:
> + "none" : No WP
> + "controller" : Uses eSDHC controller internal WP signal
> + "gpio" : Uses GPIO pin for WP
> +- gpios : Should specify GPIOs in this order: CD GPIO, WP GPIO, if
> + properties cd-type and wp-type are "gpio".
Again, be explicit in your gpios property names. Create a different
property for each gpio: cd-gpios and wp-gpios.
As for wp-type and cd-type, I think you can drop them. Default to
internal controller CD and WP pins. Use gpio if cd-gpios or wp-gpios
is present, and define specific properties for the no-wp, no-cd and
fixed-card cases. (can you tell that I'm not a fan of the "*-type"
binding for this driver?) :-)
> +
> +Examples:
> +
> +esdhc at 70004000 {
> + compatible = "fsl,imx51-esdhc";
> + reg = <0x70004000 0x4000>;
> + interrupts = <1>;
> + fsl,cd-type = "controller";
> + fsl,wp-type = "controller";
> +};
> +
> +esdhc at 70008000 {
> + compatible = "fsl,imx51-esdhc";
> + reg = <0x70008000 0x4000>;
> + interrupts = <2>;
> + fsl,cd-type = "gpio";
> + fsl,wp-type = "gpio";
> + cd-gpios = <&gpio0 6 0>; /* GPIO1_6 */
> + wp-gpios = <&gpio0 5 0>; /* GPIO1_5 */
> +};
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index 1edda29..593d6b9 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -20,6 +20,9 @@
> #include <linux/mmc/host.h>
> #include <linux/mmc/mmc.h>
> #include <linux/mmc/sdio.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_gpio.h>
> #include <mach/esdhc.h>
> #include "sdhci-pltfm.h"
> #include "sdhci-esdhc.h"
> @@ -72,6 +75,14 @@ static struct platform_device_id imx_esdhc_devtype[] = {
> }
> };
>
> +static const struct of_device_id imx_esdhc_dt_ids[] = {
> + { .compatible = "fsl,imx25-esdhc", .data = &imx_esdhc_devtype[IMX25_ESDHC], },
> + { .compatible = "fsl,imx35-esdhc", .data = &imx_esdhc_devtype[IMX35_ESDHC], },
> + { .compatible = "fsl,imx51-esdhc", .data = &imx_esdhc_devtype[IMX51_ESDHC], },
> + { .compatible = "fsl,imx53-esdhc", .data = &imx_esdhc_devtype[IMX53_ESDHC], },
> + { /* sentinel */ }
> +};
> +
> static inline int is_imx25_esdhc(struct pltfm_imx_data *data)
> {
> return data->devtype == IMX25_ESDHC;
> @@ -305,24 +316,96 @@ static irqreturn_t cd_irq(int irq, void *data)
> return IRQ_HANDLED;
> };
>
> +#ifdef CONFIG_OF
> +static const char *cd_types[] = {
> + [ESDHC_CD_NONE] = "none",
> + [ESDHC_CD_CONTROLLER] = "controller",
> + [ESDHC_CD_GPIO] = "gpio",
> + [ESDHC_CD_PERMANENT] = "permanent",
> +};
> +
> +static const char *wp_types[] = {
> + [ESDHC_WP_NONE] = "none",
> + [ESDHC_WP_CONTROLLER] = "controller",
> + [ESDHC_WP_GPIO] = "gpio",
> +};
> +
> +static int __devinit sdhci_esdhc_imx_probe_dt(struct platform_device *pdev)
> +{
> + const struct of_device_id *of_id =
> + of_match_device(imx_esdhc_dt_ids, &pdev->dev);
> + struct device_node *np = pdev->dev.of_node;
> + struct esdhc_platform_data *boarddata;
> + int err, i;
> + const char *cd, *wp;
> +
> + if (!np)
> + return -ENODEV;
> +
> + boarddata = kzalloc(sizeof(*boarddata), GFP_KERNEL);
> + if (!boarddata)
> + return -ENOMEM;
> + pdev->dev.platform_data = boarddata;
This is illegal. As far as device drivers are concerned,
pdev->dev.platform_data is immutable and must not be changed.
Otherwise they break the driver model. If you need to keep around a
platform_data structure, then it needs to be stored in the driver
private data. Your best option is to refactor the driver to not
reference pdev->dev.platform_data after probe() exits.
> +
> + err = of_property_read_string(np, "fsl,cd-type", &cd);
> + if (err)
> + return err;
> + for (i = 0; i < ARRAY_SIZE(cd_types); i++)
> + if (!strcasecmp(cd, cd_types[i])) {
> + boarddata->cd_type = i;
> + break;
> + }
> +
> + err = of_property_read_string(np, "fsl,wp-type", &wp);
> + if (err)
> + return err;
> + for (i = 0; i < ARRAY_SIZE(wp_types); i++)
> + if (!strcasecmp(wp, wp_types[i])) {
> + boarddata->wp_type = i;
> + break;
> + }
> +
> + boarddata->cd_gpio = of_get_gpio(np, 0);
> + boarddata->wp_gpio = of_get_gpio(np, 1);
> +
> + pdev->id_entry = of_id->data;
> +
> + return 0;
> +}
> +#else
> +static inline int sdhci_esdhc_imx_probe_dt(struct platform_device *pdev)
> +{
> + return 0;
> +}
> +#endif
> +
> static int __devinit sdhci_esdhc_imx_probe(struct platform_device *pdev)
> {
> + struct device_node *np = pdev->dev.of_node;
> struct sdhci_pltfm_host *pltfm_host;
> struct sdhci_host *host;
> - struct esdhc_platform_data *boarddata;
> + struct esdhc_platform_data *boarddata = NULL;
> struct clk *clk;
> int err;
> struct pltfm_imx_data *imx_data;
>
> + err = sdhci_esdhc_imx_probe_dt(pdev);
> + if (err)
> + return err;
> +
> host = sdhci_pltfm_init(pdev, &sdhci_esdhc_imx_pdata);
> - if (IS_ERR(host))
> - return PTR_ERR(host);
> + if (IS_ERR(host)) {
> + err = PTR_ERR(host);
> + goto err_sdhci_pltfm;
> + }
>
> pltfm_host = sdhci_priv(host);
>
> imx_data = kzalloc(sizeof(struct pltfm_imx_data), GFP_KERNEL);
> - if (!imx_data)
> - return -ENOMEM;
> + if (!imx_data) {
> + err = -ENOMEM;
> + goto err_imx_data;
> + }
>
> imx_data->devtype = pdev->id_entry->driver_data;
> pltfm_host->priv = imx_data;
> @@ -416,12 +499,17 @@ no_board_data:
> clk_put(pltfm_host->clk);
> err_clk_get:
> kfree(imx_data);
> +err_imx_data:
> sdhci_pltfm_free(pdev);
> +err_sdhci_pltfm:
> + if (np)
> + kfree(boarddata);
> return err;
> }
>
> static int __devexit sdhci_esdhc_imx_remove(struct platform_device *pdev)
> {
> + struct device_node *np = pdev->dev.of_node;
> struct sdhci_host *host = platform_get_drvdata(pdev);
> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> struct esdhc_platform_data *boarddata = host->mmc->parent->platform_data;
> @@ -444,6 +532,9 @@ static int __devexit sdhci_esdhc_imx_remove(struct platform_device *pdev)
>
> sdhci_pltfm_free(pdev);
>
> + if (np)
> + kfree(boarddata);
> +
> return 0;
> }
>
> @@ -451,6 +542,7 @@ static struct platform_driver sdhci_esdhc_imx_driver = {
> .driver = {
> .name = "sdhci-esdhc-imx",
> .owner = THIS_MODULE,
> + .of_match_table = imx_esdhc_dt_ids,
> },
> .id_table = imx_esdhc_devtype,
> .probe = sdhci_esdhc_imx_probe,
> --
> 1.7.4.1
>
>
>
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
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