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    Subject[PATCH V6 13/24] mmc: sdhci-uhs2: add set_timeout()
    Date
    This is a UHS-II version of sdhci's set_timeout() 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-uhs2.c | 72 +++++++++++++++++++++++++++++++++++
    drivers/mmc/host/sdhci-uhs2.h | 1 +
    2 files changed, 73 insertions(+)

    diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
    index 2342c05c4cdb..00b1b69b49ea 100644
    --- a/drivers/mmc/host/sdhci-uhs2.c
    +++ b/drivers/mmc/host/sdhci-uhs2.c
    @@ -13,6 +13,7 @@
    #include <linux/delay.h>
    #include <linux/module.h>
    #include <linux/iopoll.h>
    +#include <linux/bitfield.h>

    #include "sdhci.h"
    #include "sdhci-uhs2.h"
    @@ -141,6 +142,77 @@ static void sdhci_uhs2_set_power(struct sdhci_host *host, unsigned char mode,
    }
    }

    +static u8 sdhci_calc_timeout_uhs2(struct sdhci_host *host, u8 *cmd_res, u8 *dead_lock)
    +{
    + u8 count;
    + unsigned int cmd_res_timeout, dead_lock_timeout, current_timeout;
    + /* timeout in us */
    + cmd_res_timeout = 5 * 1000;
    + dead_lock_timeout = 1 * 1000 * 1000;
    +
    + /*
    + * Figure out needed cycles.
    + * We do this in steps in order to fit inside a 32 bit int.
    + * The first step is the minimum timeout, which will have a
    + * minimum resolution of 6 bits:
    + * (1) 2^13*1000 > 2^22,
    + * (2) host->timeout_clk < 2^16
    + * =>
    + * (1) / (2) > 2^6
    + */
    + count = 0;
    + current_timeout = (1 << 13) * 1000 / host->timeout_clk;
    + while (current_timeout < cmd_res_timeout) {
    + count++;
    + current_timeout <<= 1;
    + if (count >= 0xF)
    + break;
    + }
    +
    + if (count >= 0xF) {
    + DBG("%s: Too large timeout 0x%x requested for CMD_RES!\n",
    + mmc_hostname(host->mmc), count);
    + count = 0xE;
    + }
    + *cmd_res = count;
    +
    + count = 0;
    + current_timeout = (1 << 13) * 1000 / host->timeout_clk;
    + while (current_timeout < dead_lock_timeout) {
    + count++;
    + current_timeout <<= 1;
    + if (count >= 0xF)
    + break;
    + }
    +
    + if (count >= 0xF) {
    + DBG("%s: Too large timeout 0x%x requested for DEADLOCK!\n",
    + mmc_hostname(host->mmc), count);
    + count = 0xE;
    + }
    + *dead_lock = count;
    +
    + return count;
    +}
    +
    +static void __sdhci_uhs2_set_timeout(struct sdhci_host *host)
    +{
    + u8 cmd_res, dead_lock;
    +
    + sdhci_calc_timeout_uhs2(host, &cmd_res, &dead_lock);
    + cmd_res |= FIELD_PREP(SDHCI_UHS2_TIMER_CTRL_DEADLOCK_MASK, dead_lock);
    + sdhci_writeb(host, cmd_res, SDHCI_UHS2_TIMER_CTRL);
    +}
    +
    +void sdhci_uhs2_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
    +{
    + __sdhci_set_timeout(host, cmd);
    +
    + if (sdhci_uhs2_mode(host))
    + __sdhci_uhs2_set_timeout(host);
    +}
    +EXPORT_SYMBOL_GPL(sdhci_uhs2_set_timeout);
    +
    /*****************************************************************************\
    * *
    * MMC callbacks *
    diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
    index 03b9f6675cdc..a58ef19c08aa 100644
    --- a/drivers/mmc/host/sdhci-uhs2.h
    +++ b/drivers/mmc/host/sdhci-uhs2.h
    @@ -177,5 +177,6 @@ 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);
    +void sdhci_uhs2_set_timeout(struct sdhci_host *host, struct mmc_command *cmd);

    #endif /* __SDHCI_UHS2_H */
    --
    2.25.1
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