Re: [RFC PATCH 4/7] mmc: sdhci: Add quirk to indicate broken POWER_CONTROL

From: Adrian Hunter
Date: Tue Aug 15 2017 - 03:48:11 EST


On 07/08/17 19:01, Kishon Vijay Abraham I wrote:
> TI's implementation of sdhci controller used in DRA7 SoC's uses
> POWER_CONTROL register for configuring IO voltage and not
> for core voltage (vdd) which is it's intended use. Add a quirk
> to indicate broken POWER_CONTROL register.

A quirk isn't needed for this. Use the ->set_power() callback instead.

>
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> ---
> drivers/mmc/host/sdhci.c | 6 ++++++
> drivers/mmc/host/sdhci.h | 2 ++
> 2 files changed, 8 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index d5050ec42481..a7465a56e6b5 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1419,6 +1419,9 @@ static void sdhci_set_power_reg(struct sdhci_host *host, unsigned char mode,
>
> mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
>
> + if (host->quirks2 & SDHCI_QUIRK2_BROKEN_POWER_CONTROL)
> + return;
> +
> if (mode != MMC_POWER_OFF)
> sdhci_writeb(host, SDHCI_POWER_ON, SDHCI_POWER_CONTROL);
> else
> @@ -1430,6 +1433,9 @@ void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
> {
> u8 pwr = 0;
>
> + if (host->quirks2 & SDHCI_QUIRK2_BROKEN_POWER_CONTROL)
> + return;
> +
> if (mode != MMC_POWER_OFF) {
> switch (1 << vdd) {
> case MMC_VDD_165_195:
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 39c7a2723906..ba94cca7c892 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -439,6 +439,8 @@ struct sdhci_host {
> #define SDHCI_QUIRK2_NO_CRC_STRIPPING (1<<16)
> /* Controller has bad caps bits, but really supports DMA */
> #define SDHCI_QUIRK2_FORCE_ADMA (1<<17)
> +/* Controller uses POWER_CONTROL for managing IO voltage and not core voltage */
> +#define SDHCI_QUIRK2_BROKEN_POWER_CONTROL (1<<18)
>
> int irq; /* Device IRQ */
> void __iomem *ioaddr; /* Mapped address */
>