diff options
Diffstat (limited to 'drivers/mmc/host/sdhci-of-esdhc.c')
| -rw-r--r-- | drivers/mmc/host/sdhci-of-esdhc.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c index 0b3f05ae8328..f2d7002e37c1 100644 --- a/drivers/mmc/host/sdhci-of-esdhc.c +++ b/drivers/mmc/host/sdhci-of-esdhc.c @@ -16,6 +16,7 @@ #include <linux/err.h> #include <linux/io.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/delay.h> #include <linux/module.h> #include <linux/sys_soc.h> @@ -560,6 +561,76 @@ static void esdhc_reset(struct sdhci_host *host, u8 mask) sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE); } +/* The SCFG, Supplemental Configuration Unit, provides SoC specific + * configuration and status registers for the device. There is a + * SDHC IO VSEL control register on SCFG for some platforms. It's + * used to support SDHC IO voltage switching. + */ +static const struct of_device_id scfg_device_ids[] = { + { .compatible = "fsl,t1040-scfg", }, + { .compatible = "fsl,ls1012a-scfg", }, + { .compatible = "fsl,ls1046a-scfg", }, + {} +}; + +/* SDHC IO VSEL control register definition */ +#define SCFG_SDHCIOVSELCR 0x408 +#define SDHCIOVSELCR_TGLEN 0x80000000 +#define SDHCIOVSELCR_VSELVAL 0x60000000 +#define SDHCIOVSELCR_SDHC_VS 0x00000001 + +static int esdhc_signal_voltage_switch(struct mmc_host *mmc, + struct mmc_ios *ios) +{ + struct sdhci_host *host = mmc_priv(mmc); + struct device_node *scfg_node; + void __iomem *scfg_base = NULL; + u32 sdhciovselcr; + u32 val; + + /* + * Signal Voltage Switching is only applicable for Host Controllers + * v3.00 and above. + */ + if (host->version < SDHCI_SPEC_300) + return 0; + + val = sdhci_readl(host, ESDHC_PROCTL); + + switch (ios->signal_voltage) { + case MMC_SIGNAL_VOLTAGE_330: + val &= ~ESDHC_VOLT_SEL; + sdhci_writel(host, val, ESDHC_PROCTL); + return 0; + case MMC_SIGNAL_VOLTAGE_180: + scfg_node = of_find_matching_node(NULL, scfg_device_ids); + if (scfg_node) + scfg_base = of_iomap(scfg_node, 0); + if (scfg_base) { + sdhciovselcr = SDHCIOVSELCR_TGLEN | + SDHCIOVSELCR_VSELVAL; + iowrite32be(sdhciovselcr, + scfg_base + SCFG_SDHCIOVSELCR); + + val |= ESDHC_VOLT_SEL; + sdhci_writel(host, val, ESDHC_PROCTL); + mdelay(5); + + sdhciovselcr = SDHCIOVSELCR_TGLEN | + SDHCIOVSELCR_SDHC_VS; + iowrite32be(sdhciovselcr, + scfg_base + SCFG_SDHCIOVSELCR); + iounmap(scfg_base); + } else { + val |= ESDHC_VOLT_SEL; + sdhci_writel(host, val, ESDHC_PROCTL); + } + return 0; + default: + return 0; + } +} + #ifdef CONFIG_PM_SLEEP static u32 esdhc_proctl; static int esdhc_of_suspend(struct device *dev) @@ -717,6 +788,9 @@ static int sdhci_esdhc_probe(struct platform_device *pdev) if (IS_ERR(host)) return PTR_ERR(host); + host->mmc_host_ops.start_signal_voltage_switch = + esdhc_signal_voltage_switch; + esdhc_init(pdev, host); sdhci_get_of_property(pdev); |