From: Philip Rakity <[email protected]> On some systems the host controller does not support vccq signaling. This is supplied by a dedicated regulator (vqmmc).
Add support for this regulator. Signed-off-by: Philip Rakity <[email protected]> --- drivers/mmc/host/sdhci.c | 179 +++++++++++++++++++++++++++++---------------- include/linux/mmc/sdhci.h | 3 +- 2 files changed, 117 insertions(+), 65 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 9a11dc3..ac50d35 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1597,57 +1597,64 @@ static void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable) spin_unlock_irqrestore(&host->lock, flags); } -static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, - struct mmc_ios *ios) +static int sdhci_do_3_3v_signal_voltage_switch(struct sdhci_host *host, + u16 ctrl) { - u8 pwr; - u16 clk, ctrl; - u32 present_state; - - /* - * Signal Voltage Switching is only applicable for Host Controllers - * v3.00 and above. - */ - if (host->version < SDHCI_SPEC_300) - return 0; - - /* - * We first check whether the request is to set signalling voltage - * to 3.3V. If so, we change the voltage to 3.3V and return quickly. - */ - ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); - if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) { - /* Set 1.8V Signal Enable in the Host Control2 register to 0 */ - ctrl &= ~SDHCI_CTRL_VDD_180; - sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2); + int ret; - /* Wait for 5ms */ - usleep_range(5000, 5500); + /* Set 1.8V Signal Enable in the Host Control2 register to 0 */ + ctrl &= ~SDHCI_CTRL_VDD_180; + sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2); - /* 3.3V regulator output should be stable within 5 ms */ - ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); - if (!(ctrl & SDHCI_CTRL_VDD_180)) - return 0; - else { + if (host->vqmmc) { + ret = regulator_set_voltage(host->vqmmc, + 3300000, 3300000); + if (ret) { pr_info(DRIVER_NAME ": Switching to 3.3V " "signalling voltage failed\n"); return -EIO; } - } else if (!(ctrl & SDHCI_CTRL_VDD_180) && - (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)) { - /* Stop SDCLK */ - clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL); - clk &= ~SDHCI_CLOCK_CARD_EN; - sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); + } + /* Wait for 5ms */ + usleep_range(5000, 5500); - /* Check whether DAT[3:0] is 0000 */ - present_state = sdhci_readl(host, SDHCI_PRESENT_STATE); - if (!((present_state & SDHCI_DATA_LVL_MASK) >> - SDHCI_DATA_LVL_SHIFT)) { - /* - * Enable 1.8V Signal Enable in the Host Control2 - * register - */ + /* 3.3V regulator output should be stable within 5 ms */ + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); + if (!(ctrl & SDHCI_CTRL_VDD_180)) + return 0; + + pr_info(DRIVER_NAME ": Switching to 3.3V signalling voltage failed\n"); + return -EIO; +} + +static int sdhci_do_1_8v_signal_voltage_switch(struct sdhci_host *host, + u16 ctrl) +{ + u8 pwr; + u16 clk; + u32 present_state; + int ret; + + /* Stop SDCLK */ + clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL); + clk &= ~SDHCI_CLOCK_CARD_EN; + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); + + /* Check whether DAT[3:0] is 0000 */ + present_state = sdhci_readl(host, SDHCI_PRESENT_STATE); + if (!((present_state & SDHCI_DATA_LVL_MASK) >> + SDHCI_DATA_LVL_SHIFT)) { + /* + * Enable 1.8V Signal Enable in the Host Control2 + * register + */ + if (host->vqmmc) + ret = regulator_set_voltage(host->vqmmc, + 1800000, 1800000); + else + ret = 0; + + if (!ret) { ctrl |= SDHCI_CTRL_VDD_180; sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2); @@ -1656,7 +1663,7 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); if (ctrl & SDHCI_CTRL_VDD_180) { - /* Provide SDCLK again and wait for 1ms*/ + /* Provide SDCLK again and wait for 1ms */ clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL); clk |= SDHCI_CLOCK_CARD_EN; sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); @@ -1673,29 +1680,54 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, return 0; } } + } - /* - * If we are here, that means the switch to 1.8V signaling - * failed. We power cycle the card, and retry initialization - * sequence by setting S18R to 0. - */ - pwr = sdhci_readb(host, SDHCI_POWER_CONTROL); - pwr &= ~SDHCI_POWER_ON; - sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL); - if (host->vmmc) - regulator_disable(host->vmmc); + /* + * If we are here, that means the switch to 1.8V signaling + * failed. We power cycle the card, and retry initialization + * sequence by setting S18R to 0. + */ + pwr = sdhci_readb(host, SDHCI_POWER_CONTROL); + pwr &= ~SDHCI_POWER_ON; + sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL); + if (host->vmmc) + regulator_disable(host->vmmc); - /* Wait for 1ms as per the spec */ - usleep_range(1000, 1500); - pwr |= SDHCI_POWER_ON; - sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL); - if (host->vmmc) - regulator_enable(host->vmmc); + /* Wait for 1ms as per the spec */ + usleep_range(1000, 1500); + pwr |= SDHCI_POWER_ON; + sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL); + if (host->vmmc) + regulator_enable(host->vmmc); - pr_info(DRIVER_NAME ": Switching to 1.8V signalling " - "voltage failed, retrying with S18R set to 0\n"); - return -EAGAIN; - } else + pr_info(DRIVER_NAME ": Switching to 1.8V signalling " + "voltage failed, retrying with S18R set to 0\n"); + return -EAGAIN; +} + +static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, + struct mmc_ios *ios) +{ + u16 ctrl; + + /* + * Signal Voltage Switching is only applicable for Host Controllers + * v3.00 and above. + */ + if (host->version < SDHCI_SPEC_300) + return 0; + + /* + * We first check whether the request is to set signalling voltage + * to 3.3V. If so, we change the voltage to 3.3V and return quickly. + */ + ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); + if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) + return sdhci_do_3_3v_signal_voltage_switch(host, ctrl); + else if (!(ctrl & SDHCI_CTRL_VDD_180) && + (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)) + return sdhci_do_1_8v_signal_voltage_switch(host, ctrl); + else /* No signal voltage switch required */ return 0; } @@ -2802,6 +2834,20 @@ int sdhci_add_host(struct sdhci_host *host) !(host->mmc->caps & MMC_CAP_NONREMOVABLE)) mmc->caps |= MMC_CAP_NEEDS_POLL; + /* if vqmmc regulator and no 1.8V signaling no UHS */ + + host->vqmmc = regulator_get(mmc_dev(mmc), "vqmmc"); + if (IS_ERR(host->vqmmc)) { + pr_info("%s: no vqmmc regulator found\n", + mmc_hostname(mmc)); + host->vqmmc = NULL; + } else if (regulator_is_supported_voltage(host->vqmmc, + 1800000, 1800000)) + regulator_enable(host->vqmmc); + else + caps[1] &= ~(SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 | + SDHCI_SUPPORT_DDR50); + /* Any UHS-I mode in caps implies SDR12 and SDR25 support. */ if (caps[1] & (SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 | SDHCI_SUPPORT_DDR50)) @@ -3122,6 +3168,11 @@ void sdhci_remove_host(struct sdhci_host *host, int dead) if (host->vmmc) regulator_put(host->vmmc); + if (host->vqmmc) { + regulator_disable(host->vqmmc); + regulator_put(host->vqmmc); + } + kfree(host->adma_desc); kfree(host->align_buffer); diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h index ac83b10..fa8529a 100644 --- a/include/linux/mmc/sdhci.h +++ b/include/linux/mmc/sdhci.h @@ -97,7 +97,8 @@ struct sdhci_host { const struct sdhci_ops *ops; /* Low level hw interface */ - struct regulator *vmmc; /* Power regulator */ + struct regulator *vmmc; /* Power regulator (vmmc) */ + struct regulator *vqmmc; /* Signaling regulator (vccq) */ /* Internal data */ struct mmc_host *mmc; /* MMC structure */ -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
