From: Muhammad Husaini Zulkifli <muhammad.husaini.zulki...@intel.com>
Voltage switching sequence is needed to support UHS-1 interface as Keem Bay EVM is using external voltage regulator to switch between 1.8V and 3.3V. Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulki...@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevche...@intel.com> Reviewed-by: Adrian Hunter <adrian.hun...@intel.com> --- drivers/mmc/host/sdhci-of-arasan.c | 140 +++++++++++++++++++++++++++++ 1 file changed, 140 insertions(+) diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c index f186fbd016b1..c133408d0c74 100644 --- a/drivers/mmc/host/sdhci-of-arasan.c +++ b/drivers/mmc/host/sdhci-of-arasan.c @@ -16,7 +16,9 @@ */ #include <linux/clk-provider.h> +#include <linux/gpio/consumer.h> #include <linux/mfd/syscon.h> +#include <linux/arm-smccc.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/phy/phy.h> @@ -41,6 +43,11 @@ #define SDHCI_ITAPDLY_ENABLE 0x100 #define SDHCI_OTAPDLY_ENABLE 0x40 +/* Setting for Keem Bay IO Pad 1.8 Voltage Selection */ +#define KEEMBAY_AON_SIP_FUNC_ID 0x8200ff26 +#define KEEMBAY_AON_SET_1V8_VOLT 0x01 +#define KEEMBAY_AON_SET_3V3_VOLT 0x00 + /* Default settings for ZynqMP Clock Phases */ #define ZYNQMP_ICLK_PHASE {0, 63, 63, 0, 63, 0, 0, 183, 54, 0, 0} #define ZYNQMP_OCLK_PHASE {0, 72, 60, 0, 60, 72, 135, 48, 72, 135, 0} @@ -150,6 +157,7 @@ struct sdhci_arasan_data { struct regmap *soc_ctl_base; const struct sdhci_arasan_soc_ctl_map *soc_ctl_map; unsigned int quirks; + struct gpio_desc *uhs_gpio; /* Controller does not have CD wired and will not function normally without */ #define SDHCI_ARASAN_QUIRK_FORCE_CDTEST BIT(0) @@ -361,6 +369,121 @@ static int sdhci_arasan_voltage_switch(struct mmc_host *mmc, return -EINVAL; } +static int sdhci_arasan_keembay_set_voltage(int volt) +{ +#if IS_ENABLED(CONFIG_HAVE_ARM_SMCCC) + struct arm_smccc_res res; + + arm_smccc_smc(KEEMBAY_AON_SIP_FUNC_ID, volt, 0, 0, 0, 0, 0, 0, &res); + if (res.a0) + return -EINVAL; + return 0; +#else + return -EINVAL; +#endif +} + +static int sdhci_arasan_keembay_voltage_switch(struct mmc_host *mmc, + struct mmc_ios *ios) +{ + struct sdhci_host *host = mmc_priv(mmc); + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); + struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); + u16 ctrl_2; + u16 clk; + int ret; + + switch (ios->signal_voltage) { + case MMC_SIGNAL_VOLTAGE_180: + clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL); + clk &= ~SDHCI_CLOCK_CARD_EN; + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); + + clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL); + if (clk & SDHCI_CLOCK_CARD_EN) + return -EAGAIN; + + sdhci_writeb(host, SDHCI_POWER_ON | SDHCI_POWER_180, + SDHCI_POWER_CONTROL); + + /* Set VDDIO_B voltage to Low for 1.8V */ + gpiod_set_value_cansleep(sdhci_arasan->uhs_gpio, 0); + + /* + * This is like final gatekeeper. Need to ensure changed voltage + * is settled before and after turn on this bit. + */ + usleep_range(1000, 1100); + + ret = sdhci_arasan_keembay_set_voltage(KEEMBAY_AON_SET_1V8_VOLT); + if (ret) + return ret; + + usleep_range(1000, 1100); + + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2); + ctrl_2 |= SDHCI_CTRL_VDD_180; + sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2); + + /* Sleep for 5ms to stabilize 1.8V regulator */ + usleep_range(5000, 5500); + + /* 1.8V regulator output should be stable within 5 ms */ + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2); + if (!(ctrl_2 & SDHCI_CTRL_VDD_180)) + return -EAGAIN; + + clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL); + clk |= SDHCI_CLOCK_CARD_EN; + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL); + break; + case MMC_SIGNAL_VOLTAGE_330: + /* Set VDDIO_B voltage to High for 3.3V */ + gpiod_set_value_cansleep(sdhci_arasan->uhs_gpio, 1); + + /* + * This is like final gatekeeper. Need to ensure changed voltage + * is settled before and after turn on this bit. + */ + usleep_range(1000, 1100); + + ret = sdhci_arasan_keembay_set_voltage(KEEMBAY_AON_SET_3V3_VOLT); + if (ret) + return ret; + + usleep_range(1000, 1100); + + /* Set 1.8V Signal Enable in the Host Control2 register to 0 */ + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2); + ctrl_2 &= ~SDHCI_CTRL_VDD_180; + sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2); + + /* Sleep for 5ms to stabilize 3.3V regulator */ + usleep_range(5000, 5500); + + /* 3.3V regulator output should be stable within 5 ms */ + ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2); + if (ctrl_2 & SDHCI_CTRL_VDD_180) + return -EAGAIN; + + break; + default: + return -EINVAL; + } + + return 0; +} + +static int sdhci_arasan_keembay_select_drive_strength(struct mmc_card *card, + unsigned int max_dtr, int host_drv, + int card_drv, int *drv_type) +{ + if (card->host->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_180) + *drv_type = MMC_SET_DRIVER_TYPE_C; + + return 0; +} + static const struct sdhci_ops sdhci_arasan_ops = { .set_clock = sdhci_arasan_set_clock, .get_max_clock = sdhci_pltfm_clk_get_max_clock, @@ -1521,6 +1644,7 @@ static int sdhci_arasan_probe(struct platform_device *pdev) struct sdhci_pltfm_host *pltfm_host; struct sdhci_arasan_data *sdhci_arasan; struct device_node *np = pdev->dev.of_node; + struct device *dev = &pdev->dev; const struct sdhci_arasan_of_data *data; match = of_match_node(sdhci_arasan_of_match, pdev->dev.of_node); @@ -1600,6 +1724,22 @@ static int sdhci_arasan_probe(struct platform_device *pdev) host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY; } + if (of_device_is_compatible(np, "intel,keembay-sdhci-5.1-sd")) { + struct gpio_desc *uhs; + + uhs = devm_gpiod_get_optional(dev, "uhs", GPIOD_OUT_HIGH); + if (IS_ERR(uhs)) + return dev_err_probe(dev, PTR_ERR(uhs), "can't get uhs gpio\n"); + + sdhci_arasan->uhs_gpio = uhs; + + host->mmc_host_ops.start_signal_voltage_switch = + sdhci_arasan_keembay_voltage_switch; + + host->mmc_host_ops.select_drive_strength = + sdhci_arasan_keembay_select_drive_strength; + } + sdhci_arasan_update_baseclkfreq(host); ret = sdhci_arasan_register_sdclk(sdhci_arasan, clk_xin, &pdev->dev); -- 2.17.1