Re: [PATCH 7/9] mmc: mmci: add volt_switch callbacks

From: Ulf Hansson
Date: Fri Jan 24 2020 - 08:13:15 EST


On Fri, 10 Jan 2020 at 14:49, Ludovic Barre <ludovic.barre@xxxxxx> wrote:
>
> This patch adds 2 voltage switch callbacks in mmci_host_ops:
> -prep_volt_switch allows to prepare voltage switch before to
> sent the SD_SWITCH_VOLTAGE command (cmd11).
> -volt_switch callback allows to define specific action after
> regulator set voltage.

I am fine with adding these callbacks, however I strongly suggest to
have a reference to "signal voltage" in the name of the callbacks. As
to avoid confusion for what there are used for.

Perhaps ->post_sig_volt_switch() and ->pre_sig_volt_switch() can work?

>
> Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
> ---
> drivers/mmc/host/mmci.c | 8 ++++++++
> drivers/mmc/host/mmci.h | 2 ++
> 2 files changed, 10 insertions(+)
>
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index 00b473f57047..d76a59c06cb0 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -22,6 +22,7 @@
> #include <linux/mmc/pm.h>
> #include <linux/mmc/host.h>
> #include <linux/mmc/card.h>
> +#include <linux/mmc/sd.h>
> #include <linux/mmc/slot-gpio.h>
> #include <linux/amba/bus.h>
> #include <linux/clk.h>
> @@ -1207,6 +1208,9 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
> writel_relaxed(clks, host->base + MMCIDATATIMER);
> }
>
> + if (host->ops->prep_volt_switch && cmd->opcode == SD_SWITCH_VOLTAGE)
> + host->ops->prep_volt_switch(host);
> +
> if (/*interrupt*/0)
> c |= MCI_CPSM_INTERRUPT;
>
> @@ -1820,6 +1824,7 @@ static int mmci_get_cd(struct mmc_host *mmc)
>
> static int mmci_sig_volt_switch(struct mmc_host *mmc, struct mmc_ios *ios)
> {
> + struct mmci_host *host = mmc_priv(mmc);
> int ret = 0;
>
> if (!IS_ERR(mmc->supply.vqmmc)) {
> @@ -1839,6 +1844,9 @@ static int mmci_sig_volt_switch(struct mmc_host *mmc, struct mmc_ios *ios)
> break;
> }
>
> + if (!ret && host->ops && host->ops->volt_switch)
> + ret = host->ops->volt_switch(host, ios);
> +
> if (ret)
> dev_warn(mmc_dev(mmc), "Voltage switch failed\n");
> }
> diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
> index ddcdfb827996..c04a144259a2 100644
> --- a/drivers/mmc/host/mmci.h
> +++ b/drivers/mmc/host/mmci.h
> @@ -377,6 +377,8 @@ struct mmci_host_ops {
> void (*set_clkreg)(struct mmci_host *host, unsigned int desired);
> void (*set_pwrreg)(struct mmci_host *host, unsigned int pwr);
> bool (*busy_complete)(struct mmci_host *host, u32 status, u32 err_msk);
> + void (*prep_volt_switch)(struct mmci_host *host);
> + int (*volt_switch)(struct mmci_host *host, struct mmc_ios *ios);
> };
>
> struct mmci_host {
> --
> 2.17.1
>

Kind regards
Uffe