On 3 March 2016 at 16:28, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> On 16 February 2016 at 05:06, Magnus Damm <magnus.damm@xxxxxxxxx> wrote:
>> From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
>>
>> This patch adds comments to describe the various ways card detection
>> may be implemented and when polling is needed. Also a fix is included
>> to prevent the MMC SPI driver from polling when a CD GPIO that supports
>> interrupts is specified using the gpios DT property (case 1).
>>
>> Without this patch the DT node below results in the following output:
>>
>> spi_gpio: spi-gpio { /* SD2 @ CN12 */
>> compatible = "spi-gpio";
>> #address-cells = <1>;
>> #size-cells = <0>;
>> gpio-sck = <&gpio6 16 GPIO_ACTIVE_HIGH>;
>> gpio-mosi = <&gpio6 17 GPIO_ACTIVE_HIGH>;
>> gpio-miso = <&gpio6 18 GPIO_ACTIVE_HIGH>;
>> num-chipselects = <1>;
>> cs-gpios = <&gpio6 21 GPIO_ACTIVE_LOW>;
>> status = "okay";
>>
>> spi@0 {
>> compatible = "mmc-spi-slot";
>> reg = <0>;
>> voltage-ranges = <3200 3400>;
>> spi-max-frequency = <25000000>;
>> gpios = <&gpio6 22 GPIO_ACTIVE_LOW>; /* CD */
>> };
>> };
>>
>> # dmesg | grep mmc
>> mmc_spi spi32766.0: SD/MMC host mmc0, no WP, no poweroff, cd polling
>> mmc0: host does not support reading read-only switch, assuming write-enable
>> mmc0: new SDHC card on SPI
>> mmcblk0: mmc0:0000 SU04G 3.69 GiB
>> mmcblk0: p1
>>
>> With this patch applied the "cd polling" portion above disappears.
>>
>> Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
>
> This looks good to me. Although do you think we need this for @stable as well?
Ehh, as I am soon will be travelling and wanted this to be tested in
linux next, I took the liberty to remove the comments, updated the
change log and applied a stable tag.
If think the comments are useful, please send a separate patch on top.
So applied for fixes! Please have a look to make sure I looks okay to you.
Kind regards
Uffe
>
> Kind regards
> Uffe
>
>> ---
>>
>> Developed on top of renesas-drivers-2016-02-09-v4.5-rc3 which
>> simply put is v4.5-rc3 + selected linux-next trees.
>>
>> drivers/mmc/host/mmc_spi.c | 14 ++++++++++++++
>> 1 file changed, 14 insertions(+)
>>
>> --- 0001/drivers/mmc/host/mmc_spi.c
>> +++ work/drivers/mmc/host/mmc_spi.c 2016-02-16 12:47:47.900513000 +0900
>> @@ -1437,11 +1437,25 @@ static int mmc_spi_probe(struct spi_devi
>> if (status != 0)
>> goto fail_add_host;
>>
>> + /* Card detection in case of DT is supported in several ways:
>> + * 1) GPIO with interrupt support using "gpios" DT property.
>> + * 2) GPIO without interrupt support using "gpios" DT property.
>> + * 3) Interrupt only using "interrupt-parent/interrupts" DT properties.
>> + * 4) Both "gpios" and "interrupt-parent/interrupts" DT properties.
>> + * 5) Nothing specified.
>> + * For case 2 and 5 above polling is required.
>> + */
>> if (host->pdata && host->pdata->flags & MMC_SPI_USE_CD_GPIO) {
>> status = mmc_gpio_request_cd(mmc, host->pdata->cd_gpio,
>> host->pdata->cd_debounce);
>> if (status != 0)
>> goto fail_add_host;
>> +
>> + /* The platform has a CD GPIO signal that may support
>> + * interrupts, so let mmc_gpiod_request_cd_irq() decide
>> + * if polling is needed or not.
>> + */
>> + mmc->caps &= ~MMC_CAP_NEEDS_POLL;
>> mmc_gpiod_request_cd_irq(mmc);
>> }
>>
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