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

[Girish K S]

On 16 July 2012 09:45, Girish K S <girish.shivananjappa@xxxxxxxxxx> wrote:
> 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.
Sorry not allocation but declaration
> 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
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>> the body of a message to majordomo@xxxxxxxxxxxxxxx
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/