renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-19 10:44:14 +08:00
Code

mmc: sdhci: Add regulator support for vccq (voltage regualor)

Browse Source 
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@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Philip Rakity 2012-07-23 15:56:23 -07:00 committed by Chris Ball
parent 137ccd46c5
commit 6231f3de13
2 changed files with 119 additions and 67 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

183
drivers/mmc/host/sdhci.c
View File

@ -1597,57 +1597,65 @@ 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;
int ret;
/*
* Signal Voltage Switching is only applicable for Host Controllers
* v3.00 and above.
*/
if (host->version < SDHCI_SPEC_300)
return 0;
/* Set 1.8V Signal Enable in the Host Control2 register to 0 */
ctrl &= ~SDHCI_CTRL_VDD_180;
sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
/*
* 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);
/* Wait for 5ms */
usleep_range(5000, 5500);
/* 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 {
pr_info(DRIVER_NAME ": Switching to 3.3V "
"signalling voltage failed\n");
if (host->vqmmc) {
ret = regulator_set_voltage(host->vqmmc, 3300000, 3300000);
if (ret) {
pr_warning("%s: Switching to 3.3V signalling voltage "
" failed\n", mmc_hostname(host->mmc));
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_warning("%s: 3.3V regulator output did not became stable\n",
mmc_hostname(host->mmc));
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 +1664,7 @@ 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 +1681,55 @@ 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_warning("%s: Switching to 1.8V signalling voltage failed, "
"retrying with S18R set to 0\n", mmc_hostname(host->mmc));
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 +2836,18 @@ 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 signalling, then there's 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);

3
include/linux/mmc/sdhci.h
View File

@ -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 */