From: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@xxxxxxxxx>
Voltage switching sequence is needed to support UHS-1 interface.
There are 2 places to control the voltage.
1) By setting the AON register using firmware driver calling
system-level platform management layer (SMC) to set the register.
2) By controlling the GPIO expander value to drive either 1.8V or 3.3V
for power mux input.
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@xxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
Reviewed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
drivers/mmc/host/sdhci-of-arasan.c | 127 +++++++++++++++++++++++++++++
1 file changed, 127 insertions(+)
diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index f186fbd016b1..73941418eaa7 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -16,6 +16,7 @@
*/
#include <linux/clk-provider.h>
+#include <linux/gpio/consumer.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_device.h>
@@ -23,6 +24,7 @@
#include <linux/regmap.h>
#include <linux/of.h>
#include <linux/firmware/xlnx-zynqmp.h>
+#include <linux/firmware/intel/keembay_smc.h>
#include "cqhci.h"
#include "sdhci-pltfm.h"
@@ -150,6 +152,7 @@ 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 +364,113 @@ static int sdhci_arasan_voltage_switch(struct mmc_host *mmc,
return -EINVAL;
}
+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
+ * which is controlling by GPIO Expander.
+ */
+ 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 = keembay_sd_voltage_selection(KEEMBAY_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
+ * which is controlling by GPIO Expander.
+ */
+ 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 = keembay_sd_voltage_selection(KEEMBAY_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 +1631,7 @@ 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 +1711,22 @@ 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
