[PATCH v2 3/3] mmc: sdhci-esdhc-imx: add device tree probe support

Shawn Guo shawn.guo at freescale.com
Tue Jul 5 23:31:47 EDT 2011


On Tue, Jul 05, 2011 at 11:54:34AM -0600, Grant Likely wrote:
> 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.
> 
Sorry. I fixed the example below.  But this one got missed.

> 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?)  :-)
> 
Ok, I'm getting to know you.

> > +
> > +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.
> 
Ok.  I saw a patch from Troy doing this.  Will incorporate it into
the series.

Regards,
Shawn

> > +
> > +       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




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