[PATCH v5] mmc: sdhci-s3c: Add device tree support
Thomas Abraham
thomas.abraham at linaro.org
Fri Aug 24 13:59:38 EST 2012
On 24 August 2012 05:28, Jaehoon Chung <jh80.chung at samsung.com> wrote:
> On 08/24/2012 02:10 AM, Thomas Abraham wrote:
>> Add device tree based discovery support for Samsung's sdhci controller
>>
>> Cc: Ben Dooks <ben-linux at fluff.org>
>> Cc: Kukjin Kim <kgene.kim at samsung.com>
>> Cc: Chris Ball <cjb at laptop.org>
>> Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
>> ---
>> Changes since v4:
>> Adapted to new mmc core card detection bindings as specfied in the patch:
>> [PATCH] mmc: dt: Add card-detection properties to core binding
>> and extends it "samsung,cd-pinmux-gpio" property as suggested by
>> Mitch Bradley <wmb at firmworks.com>
>>
>> Changes since v3:
>>
>> The patch series that adds device tree support for Samsung sdhci controller
>> had six patches in total, of which, the first five patches have been accepted.
>> The sixth patch in the series was dropped since it was using custom Samsung
>> properties for descrbing the bus-width and card-detect gpio, but had otherwise
>> addressed all the comments.
>>
>> This patch reworks the sixth patch in v3 of the sdhci device tree support
>> patch series. The only change in this patch from the v3 version is the use of
>> generic mmc bindings for descrbing the bus-width and card-detect gpio.
>>
>> .../devicetree/bindings/mmc/samsung-sdhci.txt | 53 +++++++
>> drivers/mmc/host/sdhci-s3c.c | 162 +++++++++++++++++++-
>> 2 files changed, 209 insertions(+), 6 deletions(-)
>> create mode 100644 Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
>>
>> diff --git a/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
>> new file mode 100644
>> index 0000000..361c2ee
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mmc/samsung-sdhci.txt
>> @@ -0,0 +1,53 @@
>> +* Samsung's SDHCI Controller device tree bindings
>> +
>> +Samsung's SDHCI controller is used as a connectivity interface with external
>> +MMC, SD and eMMC storage mediums. This file documents differences between the
>> +core mmc properties described by mmc.txt and the properties used by the
>> +Samsung implmentation of the SDHCI controller.
>> +
>> +Note: The mmc core bindings documentation states that if none of the core
>> +card-detect bindings are used, then the standard sdhci card detect mechanism
>> +is used. The Samsung's SDHCI controller bindings extends this as listed below.
>> +
>> +[A] The property "samsung,cd-pinmux-gpio" can be used as stated in the
>> + "Optional Board Specific Properties" section below.
>> +
>> +[B] If core card-detect bindings and "samsung,cd-pinmux-gpio" property
>> + is not specified, it is assumed that there is no card detection
>> + mechanism used.
>> +
>> +Required SoC Specific Properties:
>> +- compatible: should be one of the following
>> + - "samsung,s3c6410-sdhci": For controllers compatible with s3c6410 sdhci
>> + controller.
>> + - "samsung,exynos4210-sdhci": For controllers compatible with Exynos4 sdhci
>> + controller.
>> +
>> +Required Board Specific Properties:
>> +- gpios: Should specify the gpios used for clock, command and data lines. The
>> + gpio specifier format depends on the gpio controller.
>> +
>> +Optional Board Specific Properties:
>> +- samsung,cd-pinmux-gpio: Specifies the card detect line that is routed
>> + through a pinmux to the card-detect pin of the card slot. This property
>> + should be used only if none of the mmc core card-detect properties are
>> + used.
>> +
>> +Example:
>> + sdhci at 12530000 {
>> + compatible = "samsung,exynos4210-sdhci";
>> + reg = <0x12530000 0x100>;
>> + interrupts = <0 75 0>;
>> + bus-width = <4>;
>> + cd-gpios = <&gpk2 2 2 3 3>;
>> + gpios = <&gpk2 0 2 0 3>, /* clock line */
>> + <&gpk2 1 2 0 3>, /* command line */
>> + <&gpk2 3 2 3 3>, /* data line 0 */
>> + <&gpk2 4 2 3 3>, /* data line 1 */
>> + <&gpk2 5 2 3 3>, /* data line 2 */
>> + <&gpk2 6 2 3 3>; /* data line 3 */
>> + };
>> +
>> + Note: This example shows both SoC specific and board specific properties
>> + in a single device node. The properties can be actually be seperated
>> + into SoC specific node and board specific node.
>> diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
>> index a50c205..445910e 100644
>> --- a/drivers/mmc/host/sdhci-s3c.c
>> +++ b/drivers/mmc/host/sdhci-s3c.c
>> @@ -34,6 +34,9 @@
>>
>> #define MAX_BUS_CLK (4)
>>
>> +/* Number of gpio's used is max data bus width + command and clock lines */
>> +#define NUM_GPIOS(x) (x + 2)
>> +
>> /**
>> * struct sdhci_s3c - S3C SDHCI instance
>> * @host: The SDHCI host created
>> @@ -41,6 +44,7 @@
>> * @ioarea: The resource created when we claimed the IO area.
>> * @pdata: The platform data for this controller.
>> * @cur_clk: The index of the current bus clock.
>> + * @gpios: List of gpio numbers parsed from device tree.
>> * @clk_io: The clock for the internal bus interface.
>> * @clk_bus: The clocks that are available for the SD/MMC bus clock.
>> */
>> @@ -52,6 +56,7 @@ struct sdhci_s3c {
>> unsigned int cur_clk;
>> int ext_cd_irq;
>> int ext_cd_gpio;
>> + int *gpios;
>>
>> struct clk *clk_io;
>> struct clk *clk_bus[MAX_BUS_CLK];
>> @@ -419,9 +424,125 @@ static void sdhci_s3c_setup_card_detect_gpio(struct sdhci_s3c *sc)
>> }
>> }
>>
>> +#ifdef CONFIG_OF
>> +static int __devinit sdhci_s3c_parse_dt(struct device *dev,
>> + struct sdhci_host *host, struct s3c_sdhci_platdata *pdata)
>> +{
>> + struct device_node *node = dev->of_node;
>> + struct sdhci_s3c *ourhost = to_s3c(host);
>> + u32 max_width;
>> + int gpio, cnt, ret;
>> +
>> + /* if the bus-width property is not specified, assume width as 1 */
>> + if (of_property_read_u32(node, "bus-width", &max_width))
>> + max_width = 1;
>> + pdata->max_width = max_width;
>> +
>> + ourhost->gpios = devm_kzalloc(dev, NUM_GPIOS(pdata->max_width) *
>> + sizeof(int), GFP_KERNEL);
>> + if (!ourhost->gpios)
>> + return -ENOMEM;
>> +
>> + /* get the card detection method */
>> + if (of_get_property(node, "broken-cd", 0)) {
>> + pdata->cd_type = S3C_SDHCI_CD_NONE;
>> + goto setup_bus;
>> + }
> If gpio_name didn't match with anything, it should be used the S3C_SDHCI_CD_NONE by default.
> What reason need to check this condition?
If none of the card-detect bindings are found (broken-cd,
non-removable, cd-gpios or samsung,cd-pinmux-gpio), then the card
detect type is set as S3C_SDHCI_CD_NONE. But for that, the search for
all these bindings have to be first completed. I hope I have answered
you question, if not, please let me know, I might have misunderstood
your question.
>> +
>> + if (of_get_property(node, "non-removable", 0)) {
>> + pdata->cd_type = S3C_SDHCI_CD_PERMANENT;
>> + goto setup_bus;
>> + }
>> +
>> + gpio = of_get_named_gpio(node, "cd-gpios", 0);
>> + if (gpio_is_valid(gpio)) {
>> + pdata->cd_type = S3C_SDHCI_CD_GPIO;
>> + goto found_cd;
>> + } else {
>> + if (gpio != -ENOENT) {
>> + dev_err(dev, "invalid card detect gpio specified\n");
>> + return -EINVAL;
>> + }
>> + }
> Can use "else if (gpio != -ENOENT)"
Ok. Thanks.
>> +
>> + gpio = of_get_named_gpio(node, "samsung,cd-pinmux-gpio", 0);
>> + if (gpio_is_valid(gpio)) {
>> + pdata->cd_type = S3C_SDHCI_CD_INTERNAL;
>> + goto found_cd;
>> + } else {
>> + if (gpio != -ENOENT) {
>> + dev_err(dev, "invalid card detect gpio specified\n");
>> + return -EINVAL;
>> + }
>> + }
>> +
>> + dev_info(dev, "assuming no card detect line available\n");
>> + pdata->cd_type = S3C_SDHCI_CD_NONE;
>> +
>> + found_cd:
>> + if (pdata->cd_type == S3C_SDHCI_CD_GPIO) {
>> + pdata->ext_cd_gpio = gpio;
>> + ourhost->ext_cd_gpio = -1;
>> + if (of_get_property(node, "cd-inverted", NULL))
>> + pdata->ext_cd_gpio_invert = 1;
>> + } else if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL) {
>> + ret = gpio_request(gpio, "sdhci-cd");
>> + if (ret) {
>> + dev_err(dev, "card detect gpio request failed\n");
>> + return -EINVAL;
>> + }
>> + ourhost->ext_cd_gpio = gpio;
>> + }
>> +
>> + setup_bus:
>> + /* get the gpios for command, clock and data lines */
>> + for (cnt = 0; cnt < NUM_GPIOS(pdata->max_width); cnt++) {
>> + gpio = of_get_gpio(node, cnt);
>> + if (!gpio_is_valid(gpio)) {
>> + dev_err(dev, "invalid gpio[%d]\n", cnt);
>> + goto err_free_dt_cd_gpio;
>> + }
>> + ourhost->gpios[cnt] = gpio;
>> + }
>> +
>> + for (cnt = 0; cnt < NUM_GPIOS(pdata->max_width); cnt++) {
>> + ret = gpio_request(ourhost->gpios[cnt], "sdhci-gpio");
>> + if (ret) {
>> + dev_err(dev, "gpio[%d] request failed\n", cnt);
>> + goto err_free_dt_gpios;
>> + }
>> + }
>> +
>> + return 0;
>> +
>> + err_free_dt_gpios:
>> + while (--cnt >= 0)
>> + gpio_free(ourhost->gpios[cnt]);
>> + err_free_dt_cd_gpio:
>> + if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL)
>> + gpio_free(ourhost->ext_cd_gpio);
>> + return -EINVAL;
>> +}
>> +#else
>> +static int __devinit sdhci_s3c_parse_dt(struct device *dev,
>> + struct sdhci_host *host, struct s3c_sdhci_platdata *pdata)
>> +{
>> + return -EINVAL;
>> +}
>> +#endif
>> +
>> +static const struct of_device_id sdhci_s3c_dt_match[];
>> +
>> static inline struct sdhci_s3c_drv_data *sdhci_s3c_get_driver_data(
>> struct platform_device *pdev)
>> {
>> +#ifdef CONFIG_OF
>> + if (pdev->dev.of_node) {
>> + const struct of_device_id *match;
>> + match = of_match_node(sdhci_s3c_dt_match, pdev->dev.of_node);
>> + return (struct sdhci_s3c_drv_data *)match->data;
>> + }
>> +#endif
>> return (struct sdhci_s3c_drv_data *)
>> platform_get_device_id(pdev)->driver_data;
>> }
>> @@ -436,7 +557,7 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
>> struct resource *res;
>> int ret, irq, ptr, clks;
>>
>> - if (!pdev->dev.platform_data) {
>> + if (!pdev->dev.platform_data && !pdev->dev.of_node) {
>> dev_err(dev, "no device data specified\n");
>> return -ENOENT;
>> }
>> @@ -452,21 +573,28 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
>> dev_err(dev, "sdhci_alloc_host() failed\n");
>> return PTR_ERR(host);
>> }
>> + sc = sdhci_priv(host);
>>
>> pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
>> if (!pdata) {
>> ret = -ENOMEM;
>> - goto err_io_clk;
>> + goto err_pdata;
>> + }
>> +
>> + if (pdev->dev.of_node) {
>> + ret = sdhci_s3c_parse_dt(&pdev->dev, host, pdata);
>> + if (ret)
>> + goto err_pdata;
>> + } else {
>> + memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata));
>> + sc->ext_cd_gpio = -1; /* invalid gpio number */
>> }
>> - memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata));
>>
>> drv_data = sdhci_s3c_get_driver_data(pdev);
>> - sc = sdhci_priv(host);
>>
>> sc->host = host;
>> sc->pdev = pdev;
>> sc->pdata = pdata;
>> - sc->ext_cd_gpio = -1; /* invalid gpio number */
>>
>> platform_set_drvdata(pdev, host);
>>
>> @@ -631,6 +759,12 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
>> clk_put(sc->clk_io);
>>
>> err_io_clk:
>> + for (ptr = 0; ptr < NUM_GPIOS(sc->pdata->max_width); ptr++)
>> + gpio_free(sc->gpios[ptr]);
>> + if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL)
>> + gpio_free(sc->ext_cd_gpio);
>> +
>> + err_pdata:
>> sdhci_free_host(host);
>>
>> return ret;
>> @@ -638,9 +772,9 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
>>
>> static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
>> {
>> - struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
>> struct sdhci_host *host = platform_get_drvdata(pdev);
>> struct sdhci_s3c *sc = sdhci_priv(host);
>> + struct s3c_sdhci_platdata *pdata = sc->pdata;
>> int ptr;
>>
>> if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_cleanup)
>> @@ -665,6 +799,11 @@ static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
>> clk_disable(sc->clk_io);
>> clk_put(sc->clk_io);
>>
>> + if (pdev->dev.of_node) {
>> + for (ptr = 0; ptr < NUM_GPIOS(sc->pdata->max_width); ptr++)
>> + gpio_free(sc->gpios[ptr]);
>> + }
>> +
>> sdhci_free_host(host);
>> platform_set_drvdata(pdev, NULL);
>>
>> @@ -737,6 +876,16 @@ static struct platform_device_id sdhci_s3c_driver_ids[] = {
>> };
>> MODULE_DEVICE_TABLE(platform, sdhci_s3c_driver_ids);
>>
>> +#ifdef CONFIG_OF
>> +static const struct of_device_id sdhci_s3c_dt_match[] = {
>> + { .compatible = "samsung,s3c6410-sdhci", },
>> + { .compatible = "samsung,exynos4210-sdhci",
>> + .data = (void *)EXYNOS4_SDHCI_DRV_DATA },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, sdhci_s3c_dt_match);
>> +#endif
>> +
>> static struct platform_driver sdhci_s3c_driver = {
>> .probe = sdhci_s3c_probe,
>> .remove = __devexit_p(sdhci_s3c_remove),
>> @@ -744,6 +893,7 @@ static struct platform_driver sdhci_s3c_driver = {
>> .driver = {
>> .owner = THIS_MODULE,
>> .name = "s3c-sdhci",
>> + .of_match_table = of_match_ptr(sdhci_s3c_dt_match),
>> .pm = SDHCI_S3C_PMOPS,
>> },
>> };
>>
>
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