[PATCH 3/7] mmc: dw_mmc: add device tree support
Kyungmin Park
kmpark at infradead.org
Thu May 10 19:59:51 EST 2012
On 5/10/12, Thomas Abraham <thomas.abraham at linaro.org> wrote:
> Dear Mr. Park,
>
> On 2 May 2012 12:25, Kyungmin Park <kmpark at infradead.org> wrote:
>> Hi,
>>
>> On 5/2/12, Thomas Abraham <thomas.abraham at linaro.org> wrote:
>>> Add device tree based discovery support.
>>>
>>> Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
>>> ---
>>> .../devicetree/bindings/mmc/synposis-dw-mshc.txt | 85 +++++++++
>>> drivers/mmc/host/dw_mmc-pltfm.c | 24 +++
>>> drivers/mmc/host/dw_mmc.c | 181
>>> +++++++++++++++++++-
>>> drivers/mmc/host/dw_mmc.h | 10 +
>>> include/linux/mmc/dw_mmc.h | 2 +
>>> 5 files changed, 296 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..c1ed70e
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/mmc/synposis-dw-mshc.txt
>>> @@ -0,0 +1,85 @@
>>> +* 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
>>> + - synopsis,dw-mshc: for controllers compliant with synopsis
>>> dw-mshc.
>> I googled the "Synopsis Designware Mobile Storage Host Controller" and
>> Synopsis released it as this name. but still I like the 'dw-mmc'
>> instead of'dw-mshc'.
>
> Ok. Synopsis abbreviates this controller as MSHC in their datasheets
> available online. Since device tree is more about describing the
> hardware, using MSHC as the abbreviation will help with correlating
> hardware specs with the dts file. So I would prefer to continue using
> mshc as the abbreviation.
Then why author of this file uses "dw-mmc" instead of "dw-mshc"? and
it uses 'dw_mci' prefix at functions. I just worried and don't want to
give confusion to users who uses this device.
>
>>> +
>>> +* 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.
>>> +
>>> +# 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 slot child node
>>> should
>>> + 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.
>>> +
>>> + * 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:
>>> +
>>> +* 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.
>>> +
>>> +Example:
>>> +
>>> + The MSHC controller node can be split into two portions, SoC specific
>>> and
>>> + board specific portions as listed below.
>>> +
>>> + dwmmc0 at 12200000 {
>>> + compatible = "synopsis,dw-mshc";
>>> + reg = <0x12200000 0x1000>;
>>> + interrupts = <0 75 0>;
>>> + };
>>> +
>>> + dwmmc0 at 12200000 {
>>> + supports-highspeed;
>>> + card-detection-broken;
>>> + no-write-protect;
>>> + fifo-depth = <0x80>;
>>> + card-detect-delay = <200>;
>>> +
>>> + slot0 {
>>> + 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 92ec3eb..2b2c9bd 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 = "synopsis,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[];
>>> +#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);
>>> + 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 38cb7f8..bcf66d7 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;
>>>
>>> @@ -816,6 +822,8 @@ static int dw_mci_get_ro(struct mmc_host *mmc)
>>> read_only = 0;
>>> else if (brd->get_ro)
>>> read_only = brd->get_ro(slot->id);
>>> + else if (gpio_is_valid(slot->wp_gpio))
>>> + read_only = gpio_get_value(slot->wp_gpio);
>>> else
>>> read_only =
>>> mci_readl(slot->host, WRTPRT) & (1 << slot->id) ? 1
>>> : 0;
>>> @@ -837,6 +845,8 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
>>> present = 1;
>>> else if (brd->get_cd)
>>> present = !brd->get_cd(slot->id);
>>> + else if (gpio_is_valid(slot->cd_gpio))
>>> + present = gpio_get_value(slot->cd_gpio);
>>> else
>>> present = (mci_readl(slot->host, CDETECT) & (1 <<
>>> slot->id))
>>> == 0 ? 1 : 0;
>>> @@ -1747,6 +1757,96 @@ 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;
>>> + char name[7];
>>> +
>>> + if (!dev || !dev->of_node)
>>> + return NULL;
>>> +
>>> + for_each_child_of_node(dev->of_node, np) {
>>> + sprintf(name, "slot%d", slot);
>>> + if (!strcmp(name, np->name))
>>> + 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;
>>> +
>>> + 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;
>>> @@ -1760,6 +1860,7 @@ 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);
>>> @@ -1780,12 +1881,21 @@ static int __init dw_mci_init_slot(struct dw_mci
>>> *host, unsigned int id)
>>> if (host->pdata->caps)
>>> mmc->caps = host->pdata->caps;
>>>
>>> + mmc->caps |= host->drv_data->caps;
>>> +
>>> 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);
>>> + if (bus_width >= 4)
>>> + mmc->caps |= MMC_CAP_4_BIT_DATA;
>> In case of bus_width has 8; then how to handle it? maybe it's missing
>> one.
>
>
> Yes, this was not correct. I will fix this. Thanks for pointing this out.
>
>
>>> + dw_mci_of_setup_bus(host, slot->id, bus_width);
>>> + }
>>>
>>> if (host->pdata->quirks & DW_MCI_QUIRK_HIGHSPEED)
>>> mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;
>>> @@ -1830,7 +1940,6 @@ 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)
>>> @@ -1923,15 +2032,75 @@ 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, *slot;
>>> + u32 timing[3];
>>> + 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 */
>>> + for_each_child_of_node(np, slot)
>>> + pdata->num_slots++;
>>> +
>>> + /* 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;
>>>
>>> - 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..8b8862b 100644
>>> --- a/drivers/mmc/host/dw_mmc.h
>>> +++ b/drivers/mmc/host/dw_mmc.h
>>> @@ -182,4 +182,14 @@ 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
>>> +#define DW_MCI_TYPE_EXYNOS5250 1 /* Samsung Exynos5250
>>> Extensions */
>> Um. it's not good idea to add specific SOC version. And as you know,
>> exynos4 series has this controller.
>
> There are some differences between the Exynos4 and Exynos5 mshc
> controllers. For instance, the DIVRATIO field in the CLKSEL register
> is available only in Exynos5 and there are 8 phase shift values in
> Exynos5 when compared to 4 phase shift values in Exynos4. Likewise,
> there are some other differences. So to handle these specific
> implementations, we need to define types (or variants) of the
> controller. Using SoC names for the type would help in readability of
> the different types of implementations that are defined. So I would
> prefer to continue using SoC names for this.
You mean if it supports the exynos4, then it should be add exynos4 type?
Thank you,
Kyungmin Park
>
> Thanks,
> Thomas.
> --
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