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mmc: sdhci: Add helper functions for UHS modes 

Add a set_voltage() function which handles the switch from 3.3V to 1.8V
for SD card UHS modes.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
This commit is contained in:
Faiz Abbas 2021-02-04 15:10:46 +05:30 committed by Lokesh Vutla
parent bfefa3a4eb
commit 43392b550e
2 changed files with 105 additions and 0 deletions
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95
drivers/mmc/sdhci.c
View File

@ -20,6 +20,7 @@
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <phys2bus.h>
#include <power/regulator.h>
static void sdhci_reset(struct sdhci_host *host, u8 mask)
{
@ -509,6 +510,100 @@ void sdhci_set_uhs_timing(struct sdhci_host *host)
sdhci_writew(host, reg, SDHCI_HOST_CONTROL2);
}
static void sdhci_set_voltage(struct sdhci_host *host)
{
if (IS_ENABLED(CONFIG_MMC_IO_VOLTAGE)) {
struct mmc *mmc = (struct mmc *)host->mmc;
u32 ctrl;
ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
switch (mmc->signal_voltage) {
case MMC_SIGNAL_VOLTAGE_330:
#if CONFIG_IS_ENABLED(DM_REGULATOR)
if (mmc->vqmmc_supply) {
if (regulator_set_enable_if_allowed(mmc->vqmmc_supply, false)) {
pr_err("failed to disable vqmmc-supply\n");
return;
}
if (regulator_set_value(mmc->vqmmc_supply, 3300000)) {
pr_err("failed to set vqmmc-voltage to 3.3V\n");
return;
}
if (regulator_set_enable_if_allowed(mmc->vqmmc_supply, true)) {
pr_err("failed to enable vqmmc-supply\n");
return;
}
}
#endif
if (IS_SD(mmc)) {
ctrl &= ~SDHCI_CTRL_VDD_180;
sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
}
/* Wait for 5ms */
mdelay(5);
/* 3.3V regulator output should be stable within 5 ms */
if (IS_SD(mmc)) {
if (ctrl & SDHCI_CTRL_VDD_180) {
pr_err("3.3V regulator output did not become stable\n");
return;
}
}
break;
case MMC_SIGNAL_VOLTAGE_180:
#if CONFIG_IS_ENABLED(DM_REGULATOR)
if (mmc->vqmmc_supply) {
if (regulator_set_enable_if_allowed(mmc->vqmmc_supply, false)) {
pr_err("failed to disable vqmmc-supply\n");
return;
}
if (regulator_set_value(mmc->vqmmc_supply, 1800000)) {
pr_err("failed to set vqmmc-voltage to 1.8V\n");
return;
}
if (regulator_set_enable_if_allowed(mmc->vqmmc_supply, true)) {
pr_err("failed to enable vqmmc-supply\n");
return;
}
}
#endif
if (IS_SD(mmc)) {
ctrl |= SDHCI_CTRL_VDD_180;
sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
}
/* Wait for 5 ms */
mdelay(5);
/* 1.8V regulator output has to be stable within 5 ms */
if (IS_SD(mmc)) {
if (!(ctrl & SDHCI_CTRL_VDD_180)) {
pr_err("1.8V regulator output did not become stable\n");
return;
}
}
break;
default:
/* No signal voltage switch required */
return;
}
}
}
void sdhci_set_control_reg(struct sdhci_host *host)
{
sdhci_set_voltage(host);
sdhci_set_uhs_timing(host);
}
#ifdef CONFIG_DM_MMC
static int sdhci_set_ios(struct udevice *dev)
{

10
include/sdhci.h
View File

@ -491,6 +491,16 @@ void sdhci_set_uhs_timing(struct sdhci_host *host);
/* Export the operations to drivers */
int sdhci_probe(struct udevice *dev);
int sdhci_set_clock(struct mmc *mmc, unsigned int clock);
/**
* sdhci_set_control_reg - Set control registers
*
* This is used set up control registers for voltage level and UHS speed
* mode.
*
* @host: SDHCI host structure
*/
void sdhci_set_control_reg(struct sdhci_host *host);
extern const struct dm_mmc_ops sdhci_ops;
#else
#endif