Re: [PATCH v3 5/6] mmc: dw_mmc: add device tree support

[Girish K S]

On 12 July 2012 18:24, Thomas Abraham <thomas.abraham@xxxxxxxxxx> wrote:
> Add device tree based discovery support.
>
> Signed-off-by: Thomas Abraham <thomas.abraham@xxxxxxxxxx>
> ---
>  .../devicetree/bindings/mmc/synposis-dw-mshc.txt   |  108 +++++++++++
>  drivers/mmc/host/dw_mmc-pltfm.c                    |   24 +++
>  drivers/mmc/host/dw_mmc.c                          |  201 +++++++++++++++++++-
>  drivers/mmc/host/dw_mmc.h                          |    9 +
>  include/linux/mmc/dw_mmc.h                         |    2 +
>  5 files changed, 338 insertions(+), 6 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/mmc/synposis-dw-mshc.txt
>
> diff --git a/Documentation/devicetree/bindings/mmc/synposis-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/synposis-dw-mshc.txt
> new file mode 100644
> index 0000000..3acd6c9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mmc/synposis-dw-mshc.txt
> @@ -0,0 +1,108 @@
> +* Synopsis Designware Mobile Storage Host Controller
> +
> +The Synopsis designware mobile storage host controller is used to interface
> +a SoC with storage medium such as eMMC or SD/MMC cards.
> +
> +Required Properties:
> +
> +* compatible: should be one of the following
> +       - snps,dw-mshc: for controllers compliant with synopsis dw-mshc.
> +
> +* reg: physical base address of the dw-mshc controller and size of its memory
> +  region.
> +
> +* interrupts: interrupt specifier for the controller. The format and value of
> +  the interrupt specifier depends on the interrupt parent for the controller.
> +
> +* #address-cells: should be 1.
> +
> +* #size-cells: should be 0.
> +
> +# Slots: The slot specific information are contained within child-nodes with
> +  each child-node representing a supported slot. There should be atleast one
> +  child node representing a card slot. The name of the child node representing
> +  the slot is recommended to be slot@n where n is the unique number of the slot
> +  connnected to the controller. The following are optional properties which
> +  can be included in the slot child node.
> +
> +       * reg: specifies the physical slot number. The valid values of this
> +         property is 0 to (num-slots -1), where num-slots is the value
> +         specified by the num-slots property.
> +
> +       * bus-width: specifies the width of the data bus connected from the
> +         controller to the card slot. The value should be 1, 4 or 8. In case
> +         this property is not specified, a default value of 1 is assumed for
> +         this property.
> +
> +       * cd-gpios: specifies the card detect gpio line. The format of the
> +         gpio specifier depends on the gpio controller.
> +
> +       * wp-gpios: specifies the write protect gpio line. The format of the
> +         gpio specifier depends on the gpio controller.
> +
> +       * gpios: specifies a list of gpios used for command, clock and data
> +         bus. The first gpio is the command line and the second gpio is the
> +         clock line. The rest of the gpios (depending on the bus-width
> +         property) are the data lines in no particular order. The format of
> +         the gpio specifier depends on the gpio controller.
> +
> +Optional properties:
> +
> +* num-slots: specifies the number of slots supported by the controller.
> +  The number of physical slots actually used could be equal or less than the
> +  value specified by num-slots. If this property is not specified, the value
> +  of num-slot property is assumed to be 1.
> +
> +* fifo-depth: The maximum size of the tx/rx fifo's. If this property is not
> +  specified, the default value of the fifo size is determined from the
> +  controller registers.
> +
> +* card-detect-delay: Delay in milli-seconds before detecting card after card
> +  insert event. The default value is 0.
> +
> +* supports-highspeed: Enables support for high speed cards (upto 50MHz)
> +
> +* card-detection-broken: The card detection functionality is not available on
> +  any of the slots.
> +
> +* no-write-protect: The write protect pad of the controller is not connected
> +  to the write protect pin on the slot.
> +
> +Aliases:
> +
> +- All the MSHC controller nodes should be represented in the aliases node using
> +  the following format 'mshc{n}' where n is a unique number for the alias.
> +
> +
> +Example:
> +
> +  The MSHC controller node can be split into two portions, SoC specific and
> +  board specific portions as listed below.
> +
> +       dwmmc0@12200000 {
> +               compatible = "snps,dw-mshc";
> +               reg = <0x12200000 0x1000>;
> +               interrupts = <0 75 0>;
> +               #address-cells = <1>;
> +               #size-cells = <0>;
> +       };
> +
> +       dwmmc0@12200000 {
> +               num-slots = <1>;
> +               supports-highspeed;
> +               card-detection-broken;
> +               no-write-protect;
> +               fifo-depth = <0x80>;
> +               card-detect-delay = <200>;
> +
> +               slot@0 {
> +                       reg = <0>;
> +                       bus-width = <8>;
> +                       cd-gpios = <&gpc0 2 2 3 3>;
> +                       gpios = <&gpc0 0 2 0 3>, <&gpc0 1 2 0 3>,
> +                               <&gpc1 0 2 3 3>, <&gpc1 1 2 3 3>,
> +                               <&gpc1 2 2 3 3>, <&gpc1 3 2 3 3>,
> +                               <&gpc0 3 2 3 3>, <&gpc0 4 2 3 3>,
> +                               <&gpc0 5 2 3 3>, <&gpc0 6 2 3 3>;
> +               };
> +       };
> diff --git a/drivers/mmc/host/dw_mmc-pltfm.c b/drivers/mmc/host/dw_mmc-pltfm.c
> index 9a63299..8d24f6d 100644
> --- a/drivers/mmc/host/dw_mmc-pltfm.c
> +++ b/drivers/mmc/host/dw_mmc-pltfm.c
> @@ -19,8 +19,24 @@
>  #include <linux/mmc/host.h>
>  #include <linux/mmc/mmc.h>
>  #include <linux/mmc/dw_mmc.h>
> +#include <linux/of.h>
>  #include "dw_mmc.h"
>
> +#ifdef CONFIG_OF
> +static struct dw_mci_drv_data synopsis_drv_data = {
> +       .ctrl_type      = DW_MCI_TYPE_SYNOPSIS,
> +};
> +
> +static const struct of_device_id dw_mci_pltfm_match[] = {
> +       { .compatible = "snps,dw-mshc",
> +                       .data = (void *)&synopsis_drv_data, },
> +       {},
> +};
> +MODULE_DEVICE_TABLE(of, dw_mci_pltfm_match);
> +#else
> +static const struct of_device_id dw_mci_pltfm_match[];
the #else and a statement can be completely removed if of_match_ptr is
used while accessing the dw_mci_pltfm_match in of_match_node function.
> +#endif
> +
>  static int dw_mci_pltfm_probe(struct platform_device *pdev)
>  {
>         struct dw_mci *host;
> @@ -51,6 +67,13 @@ static int dw_mci_pltfm_probe(struct platform_device *pdev)
>         if (!host->regs)
>                 goto err_free;
>         platform_set_drvdata(pdev, host);
> +
> +       if (pdev->dev.of_node) {
> +               const struct of_device_id *match;
> +               match = of_match_node(dw_mci_pltfm_match, pdev->dev.of_node);
can be modified to of_match_node(of_match_pt(dw_mci_pltfm_match),
pdev->dev.of_node);
This will remove the dummy allocation of variable as mentioned above.
Also it will be generic in non dt case.
> +               host->drv_data = match->data;
> +       }
> +
>         ret = dw_mci_probe(host);
>         if (ret)
>                 goto err_out;
> @@ -111,6 +134,7 @@ static struct platform_driver dw_mci_pltfm_driver = {
>         .remove         = __exit_p(dw_mci_pltfm_remove),
>         .driver         = {
>                 .name           = "dw_mmc",
> +               .of_match_table = of_match_ptr(dw_mci_pltfm_match),
>                 .pm             = &dw_mci_pltfm_pmops,
>         },
>  };
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 075f89d..3bc276d 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -33,9 +33,13 @@
>  #include <linux/bitops.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/workqueue.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
>
>  #include "dw_mmc.h"
>
> +#define NUM_PINS(x) (x + 2)
> +
>  /* Common flag combinations */
>  #define DW_MCI_DATA_ERROR_FLAGS        (SDMMC_INT_DTO | SDMMC_INT_DCRC | \
>                                  SDMMC_INT_HTO | SDMMC_INT_SBE  | \
> @@ -86,6 +90,8 @@ struct idmac_desc {
>  struct dw_mci_slot {
>         struct mmc_host         *mmc;
>         struct dw_mci           *host;
> +       int                     wp_gpio;
> +       int                     cd_gpio;
>
>         u32                     ctype;
>
> @@ -1762,10 +1768,106 @@ static void dw_mci_work_routine_card(struct work_struct *work)
>         }
>  }
>
> +#ifdef CONFIG_OF
> +static struct device_node *dw_mci_of_find_slot_node(struct device *dev, u8 slot)
> +{
> +       struct device_node *np;
> +       const __be32 *addr;
> +       int len;
> +
> +       if (!dev || !dev->of_node)
> +               return NULL;
> +
> +       for_each_child_of_node(dev->of_node, np) {
> +               addr = of_get_property(np, "reg", &len);
> +               if (!addr || (len < sizeof(int)))
> +                       continue;
> +               if (be32_to_cpup(addr) == slot)
> +                       return np;
> +       }
> +       return NULL;
> +}
> +
> +static u32 dw_mci_of_get_bus_wd(struct device *dev, u8 slot)
> +{
> +       struct device_node *np = dw_mci_of_find_slot_node(dev, slot);
> +       u32 bus_wd = 1;
> +
> +       if (!np)
> +               return 1;
> +
> +       if (of_property_read_u32(np, "bus-width", &bus_wd))
> +               dev_err(dev, "bus-width property not found, assuming width"
> +                              " as 1\n");
> +       return bus_wd;
> +}
> +
> +static int dw_mci_of_setup_bus(struct dw_mci *host, u8 slot, u32 bus_wd)
> +{
> +       struct device_node *np = dw_mci_of_find_slot_node(host->dev, slot);
> +       int idx, gpio, ret;
> +
> +       if (!np)
> +               return -EINVAL;
> +
> +       for (idx = 0; idx < NUM_PINS(bus_wd); idx++) {
> +               gpio = of_get_gpio(np, idx);
> +               if (!gpio_is_valid(gpio)) {
> +                       dev_err(host->dev, "invalid gpio: %d\n", gpio);
> +                       return -EINVAL;
> +               }
> +
> +               ret = devm_gpio_request(host->dev, gpio, "dw-mci-bus");
> +               if (ret) {
> +                       dev_err(host->dev, "gpio [%d] request failed\n", gpio);
> +                       return -EBUSY;
> +               }
> +       }
> +
> +       host->slot[slot]->wp_gpio = -1;
> +       gpio = of_get_named_gpio(np, "wp-gpios", 0);
> +       if (!gpio_is_valid(gpio)) {
> +               dev_info(host->dev, "wp gpio not available");
> +       } else {
> +               ret = devm_gpio_request(host->dev, gpio, "dw-mci-wp");
> +               if (ret)
> +                       dev_info(host->dev, "gpio [%d] request failed\n",
> +                                               gpio);
> +               else
> +                       host->slot[slot]->wp_gpio = gpio;
> +       }
> +
> +       host->slot[slot]->cd_gpio = -1;
> +       gpio = of_get_named_gpio(np, "cd-gpios", 0);
> +       if (!gpio_is_valid(gpio)) {
> +               dev_info(host->dev, "cd gpio not available");
> +       } else {
> +               ret = devm_gpio_request(host->dev, gpio, "dw-mci-cd");
> +               if (ret)
> +                       dev_err(host->dev, "gpio [%d] request failed\n", gpio);
> +               else
> +                       host->slot[slot]->cd_gpio = gpio;
> +       }
> +
> +       return 0;
> +}
> +#else /* CONFIG_OF */
> +static u32 dw_mci_of_get_bus_wd(struct device *dev, u8 slot)
> +{
> +       return 1;
> +}
> +
> +static int dw_mci_of_setup_bus(struct dw_mci *host, u8 slot, u32 bus_wd)
> +{
> +       return -EINVAL;
> +}
> +#endif /* CONFIG_OF */
> +
>  static int __init dw_mci_init_slot(struct dw_mci *host, unsigned int id)
>  {
>         struct mmc_host *mmc;
>         struct dw_mci_slot *slot;
> +       int ctrl_id, ret;
>
>         mmc = mmc_alloc_host(sizeof(struct dw_mci_slot), host->dev);
>         if (!mmc)
> @@ -1775,6 +1877,7 @@ static int __init dw_mci_init_slot(struct dw_mci *host, unsigned int id)
>         slot->id = id;
>         slot->mmc = mmc;
>         slot->host = host;
> +       host->slot[id] = slot;
>
>         mmc->ops = &dw_mci_ops;
>         mmc->f_min = DIV_ROUND_UP(host->bus_hz, 510);
> @@ -1795,12 +1898,33 @@ static int __init dw_mci_init_slot(struct dw_mci *host, unsigned int id)
>         if (host->pdata->caps)
>                 mmc->caps = host->pdata->caps;
>
> +       if (host->dev->of_node) {
> +               ctrl_id = of_alias_get_id(host->dev->of_node, "mshc");
> +               if (ctrl_id < 0)
> +                       ctrl_id = 0;
> +       }
> +       if (host->drv_data->caps)
> +               mmc->caps |= host->drv_data->caps[ctrl_id];
> +
>         if (host->pdata->caps2)
>                 mmc->caps2 = host->pdata->caps2;
>
> -       if (host->pdata->get_bus_wd)
> +       if (host->pdata->get_bus_wd) {
>                 if (host->pdata->get_bus_wd(slot->id) >= 4)
>                         mmc->caps |= MMC_CAP_4_BIT_DATA;
> +       } else if (host->dev->of_node) {
> +               unsigned int bus_width;
> +               bus_width = dw_mci_of_get_bus_wd(host->dev, slot->id);
> +               switch (bus_width) {
> +               case 8:
> +                       mmc->caps |= MMC_CAP_8_BIT_DATA;
> +               case 4:
> +                       mmc->caps |= MMC_CAP_4_BIT_DATA;
> +               }
> +               ret = dw_mci_of_setup_bus(host, slot->id, bus_width);
> +               if (ret)
> +                       goto err_setup_bus;
> +       }
>
>         if (host->pdata->quirks & DW_MCI_QUIRK_HIGHSPEED)
>                 mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;
> @@ -1845,7 +1969,6 @@ static int __init dw_mci_init_slot(struct dw_mci *host, unsigned int id)
>         else
>                 clear_bit(DW_MMC_CARD_PRESENT, &slot->flags);
>
> -       host->slot[id] = slot;
>         mmc_add_host(mmc);
>
>  #if defined(CONFIG_DEBUG_FS)
> @@ -1862,6 +1985,10 @@ static int __init dw_mci_init_slot(struct dw_mci *host, unsigned int id)
>         queue_work(host->card_workqueue, &host->card_work);
>
>         return 0;
> +
> +err_setup_bus:
> +       mmc_free_host(mmc);
> +       return -EINVAL;
>  }
>
>  static void dw_mci_cleanup_slot(struct dw_mci_slot *slot, unsigned int id)
> @@ -1937,16 +2064,78 @@ static bool mci_wait_reset(struct device *dev, struct dw_mci *host)
>         return false;
>  }
>
> +#ifdef CONFIG_OF
> +static struct dw_mci_of_quirks {
> +       char *quirk;
> +       int id;
> +} of_quriks[] = {
> +       {
> +               .quirk  = "supports-highspeed",
> +               .id     = DW_MCI_QUIRK_HIGHSPEED,
> +       }, {
> +               .quirk  = "card-detection-broken",
> +               .id     = DW_MCI_QUIRK_BROKEN_CARD_DETECTION,
> +       }, {
> +               .quirk  = "no-write-protect",
> +               .id     = DW_MCI_QUIRK_NO_WRITE_PROTECT,
> +       }
> +};
> +
> +static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
> +{
> +       struct dw_mci_board *pdata;
> +       struct device *dev = host->dev;
> +       struct device_node *np = dev->of_node;
> +       int idx, cnt;
> +
> +       pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
> +       if (!pdata) {
> +               dev_err(dev, "could not allocate memory for pdata\n");
> +               return ERR_PTR(-ENOMEM);
> +       }
> +
> +       /* find out number of slots supported */
> +       if (of_property_read_u32(dev->of_node, "num-slots",
> +                               &pdata->num_slots)) {
> +               dev_info(dev, "num-slots property not found, "
> +                               "assuming 1 slot is available\n");
> +               pdata->num_slots = 1;
> +       }
> +
> +       /* get quirks */
> +       cnt = sizeof(of_quriks) / sizeof(struct dw_mci_of_quirks);
> +       for (idx = 0; idx < cnt; idx++)
> +               if (of_get_property(np, of_quriks[idx].quirk, NULL))
> +                       pdata->quirks |= of_quriks[idx].id;
> +
> +       if (of_property_read_u32(np, "fifo-depth", &pdata->fifo_depth))
> +               dev_info(dev, "fifo-depth property not found, using "
> +                               "value of FIFOTH register as default\n");
> +
> +       of_property_read_u32(np, "card-detect-delay", &pdata->detect_delay_ms);
> +
> +       return pdata;
> +}
> +
> +#else /* CONFIG_OF */
> +static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
> +{
> +       return ERR_PTR(-EINVAL);
> +}
> +#endif /* CONFIG_OF */
> +
>  int dw_mci_probe(struct dw_mci *host)
>  {
>         int width, i, ret = 0;
>         u32 fifo_size;
>         int init_slots = 0;
>
> -       if (!host->pdata || !host->pdata->init) {
> -               dev_err(host->dev,
> -                       "Platform data must supply init function\n");
> -               return -ENODEV;
> +       if (!host->pdata) {
> +               host->pdata = dw_mci_parse_dt(host);
> +               if (IS_ERR(host->pdata)) {
> +                       dev_err(host->dev, "platform data not available\n");
> +                       return -EINVAL;
> +               }
>         }
>
>         if (!host->pdata->select_slot && host->pdata->num_slots > 1) {
> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
> index 15c27e1..1ecaa02 100644
> --- a/drivers/mmc/host/dw_mmc.h
> +++ b/drivers/mmc/host/dw_mmc.h
> @@ -182,4 +182,13 @@ extern int dw_mci_suspend(struct dw_mci *host);
>  extern int dw_mci_resume(struct dw_mci *host);
>  #endif
>
> +/* Variations in the dw_mci controller */
> +#define DW_MCI_TYPE_SYNOPSIS           0
> +
> +/* dw_mci platform driver data */
> +struct dw_mci_drv_data {
> +       unsigned long           ctrl_type;
> +       unsigned long           *caps;
> +};
> +
>  #endif /* _DW_MMC_H_ */
> diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
> index b72e4aa..ae45e4f 100644
> --- a/include/linux/mmc/dw_mmc.h
> +++ b/include/linux/mmc/dw_mmc.h
> @@ -78,6 +78,7 @@ struct mmc_data;
>   * @data_offset: Set the offset of DATA register according to VERID.
>   * @dev: Device associated with the MMC controller.
>   * @pdata: Platform data associated with the MMC controller.
> + * @drv_data: Driver specific data for identified variant of the controller
>   * @biu_clk: Pointer to bus interface unit clock instance.
>   * @ciu_clk: Pointer to card interface unit clock instance.
>   * @slot: Slots sharing this MMC controller.
> @@ -160,6 +161,7 @@ struct dw_mci {
>         u16                     data_offset;
>         struct device           *dev;
>         struct dw_mci_board     *pdata;
> +       struct dw_mci_drv_data  *drv_data;
>         struct clk              *biu_clk;
>         struct clk              *ciu_clk;
>         struct dw_mci_slot      *slot[MAX_MCI_SLOTS];
> --
> 1.6.6.rc2
>
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