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SubjectRe: [PATCH V5 11/26] mmc: sdhci-uhs2: add reset function and uhs2_mode function
On 19/10/22 14:06, Victor Shih wrote:
> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
>
> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
> ---
> drivers/mmc/host/sdhci-pci-core.c | 1 +
> drivers/mmc/host/sdhci-pci-gli.c | 1 +
> drivers/mmc/host/sdhci-uhs2.c | 68 +++++++++++++++++++++++++++++++
> drivers/mmc/host/sdhci-uhs2.h | 3 ++
> drivers/mmc/host/sdhci.c | 3 +-
> drivers/mmc/host/sdhci.h | 14 +++++++
> 6 files changed, 89 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
> index 34ea1acbb3cc..cba5bba994b8 100644
> --- a/drivers/mmc/host/sdhci-pci-core.c
> +++ b/drivers/mmc/host/sdhci-pci-core.c
> @@ -1955,6 +1955,7 @@ static const struct sdhci_ops sdhci_pci_ops = {
> .reset = sdhci_reset,
> .set_uhs_signaling = sdhci_set_uhs_signaling,
> .hw_reset = sdhci_pci_hw_reset,
> + .uhs2_reset = sdhci_uhs2_reset,

AFAICT this isn't needed

> };
>
> /*****************************************************************************\
> diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c
> index 4d509f656188..607cf69f45d0 100644
> --- a/drivers/mmc/host/sdhci-pci-gli.c
> +++ b/drivers/mmc/host/sdhci-pci-gli.c
> @@ -1097,6 +1097,7 @@ static const struct sdhci_ops sdhci_gl9755_ops = {
> .reset = sdhci_reset,
> .set_uhs_signaling = sdhci_set_uhs_signaling,
> .voltage_switch = sdhci_gli_voltage_switch,
> + .uhs2_reset = sdhci_uhs2_reset,
> };
>
> const struct sdhci_pci_fixes sdhci_gl9755 = {
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index 08905ed081fb..0e82f98d1967 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -10,6 +10,7 @@
> * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
> */
>
> +#include <linux/delay.h>
> #include <linux/module.h>
>
> #include "sdhci.h"
> @@ -49,6 +50,73 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> }
> EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
>
> +/*****************************************************************************\
> + * *
> + * Low level functions *
> + * *
> +\*****************************************************************************/
> +
> +bool sdhci_uhs2_mode(struct sdhci_host *host)
> +{
> + if ((host->mmc->caps2 & MMC_CAP2_SD_UHS2) &&
> + (IS_ENABLED(CONFIG_MMC_SDHCI_UHS2) &&
> + (host->version >= SDHCI_SPEC_400) &&
> + (host->mmc->flags & MMC_UHS2_SUPPORT)))
> + return true;
> + else
> + return false;

For now, let's just make this:

return host->mmc->flags & MMC_UHS2_SUPPORT;

> +}
> +
> +/**
> + * sdhci_uhs2_reset - invoke SW reset
> + * @host: SDHCI host
> + * @mask: Control mask
> + *
> + * Invoke SW reset, depending on a bit in @mask and wait for completion.
> + */
> +void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask)
> +{
> + unsigned long timeout;
> + u32 val;
> +
> + if (!(sdhci_uhs2_mode(host))) {

That isn't possible.

> + /**
> + * u8 mask for legacy.
> + * u16 mask for uhs-2.
> + */
> + u8 u8_mask;
> +
> + u8_mask = (mask & 0xFF);
> + sdhci_reset(host, u8_mask);

Probably should call host->ops->reset() but !sdhci_uhs2_mode(host)
isn't possible

> +
> + return;
> + }
> +
> + sdhci_writew(host, mask, SDHCI_UHS2_SW_RESET);
> +
> + if (mask & SDHCI_UHS2_SW_RESET_FULL) {
> + host->clock = 0;
> + /* Reset-all turns off SD Bus Power */
> + if (host->quirks2 & SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON)
> + sdhci_runtime_pm_bus_off(host);

We don't know what other drivers will opt for UHS-II
support, but I doubt this quirk will be used, so let's
not support SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON for UHS-II

> + }
> +
> + /* Wait max 100 ms */
> + timeout = 10000;

Isn't that 10ms

> +
> + /* hw clears the bit when it's done */
> + if (read_poll_timeout_atomic(sdhci_readw, val, !(val & mask), 10,
> + timeout, true, host, SDHCI_UHS2_SW_RESET)) {
> + pr_err("%s: %s: Reset 0x%x never completed.\n",
> + __func__, mmc_hostname(host->mmc), (int)mask);
> + pr_err("%s: clean reset bit\n",
> + mmc_hostname(host->mmc));
> + sdhci_writeb(host, 0, SDHCI_UHS2_SW_RESET);
> + return;
> + }
> +}
> +EXPORT_SYMBOL_GPL(sdhci_uhs2_reset);
> +
> /*****************************************************************************\
> * *
> * Driver init/exit *
> diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
> index afdb05d6056b..31776dcca5cf 100644
> --- a/drivers/mmc/host/sdhci-uhs2.h
> +++ b/drivers/mmc/host/sdhci-uhs2.h
> @@ -11,6 +11,7 @@
> #define __SDHCI_UHS2_H
>
> #include <linux/bits.h>
> +#include <linux/iopoll.h>

Not needed in header. Can just be in .c

>
> /*
> * UHS-II Controller registers
> @@ -210,5 +211,7 @@
> struct sdhci_host;
>
> void sdhci_uhs2_dump_regs(struct sdhci_host *host);
> +bool sdhci_uhs2_mode(struct sdhci_host *host);
> +void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);
>
> #endif /* __SDHCI_UHS2_H */
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 2cdd183c8ada..bd017c59a020 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -194,13 +194,14 @@ static void sdhci_runtime_pm_bus_on(struct sdhci_host *host)
> pm_runtime_get_noresume(mmc_dev(host->mmc));
> }
>
> -static void sdhci_runtime_pm_bus_off(struct sdhci_host *host)
> +void sdhci_runtime_pm_bus_off(struct sdhci_host *host)
> {
> if (!host->bus_on)
> return;
> host->bus_on = false;
> pm_runtime_put_noidle(mmc_dev(host->mmc));
> }
> +EXPORT_SYMBOL_GPL(sdhci_runtime_pm_bus_off);

Let's not support SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON for UHS-II

>
> void sdhci_reset(struct sdhci_host *host, u8 mask)
> {
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index bbed850241d4..28716105da61 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -715,6 +715,19 @@ struct sdhci_ops {
> u8 power_mode);
> unsigned int (*get_ro)(struct sdhci_host *host);
> void (*reset)(struct sdhci_host *host, u8 mask);
> + /**
> + * The sdhci_uhs2_reset callback is to implement for reset
> + * @host: SDHCI host
> + * @mask: Control mask
> + *
> + * Invoke reset, depending on a bit in @mask and wait for completion.
> + * SD mode UHS-II mode
> + * SDHCI_RESET_ALL SDHCI_UHS2_SW_RESET_FULL
> + * SDHCI_RESET_CMD SDHCI_RESET_CMD
> + * SDHCI_RESET_DATA SDHCI_UHS2_SW_RESET_SD
> + *
> + **/
> + void (*uhs2_reset)(struct sdhci_host *host, u16 mask);

This is only being called from sdhci_uhs2.c so let's just call it
directly for now, instead of using a callback.

> int (*platform_execute_tuning)(struct sdhci_host *host, u32 opcode);
> void (*set_uhs_signaling)(struct sdhci_host *host, unsigned int uhs);
> void (*hw_reset)(struct sdhci_host *host);
> @@ -837,6 +850,7 @@ static inline void sdhci_read_caps(struct sdhci_host *host)
> __sdhci_read_caps(host, NULL, NULL, NULL);
> }
>
> +void sdhci_runtime_pm_bus_off(struct sdhci_host *host);

Let's not support SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON for UHS-II

> u16 sdhci_calc_clk(struct sdhci_host *host, unsigned int clock,
> unsigned int *actual_clock);
> void sdhci_set_clock(struct sdhci_host *host, unsigned int clock);

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