From: Philip Rakity <prakity@xxxxxxxxxxx>
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 <prakity@xxxxxxxxxxx>
---
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
--
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