1 files changed, 139 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c b/arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c
new file mode 100644
index 0000000..4b8ba26
--- /dev/null
+++ b/arch/arm/cpu/armv7/omap5/dra7xx_iodelay.c
@@ -0,0 +1,139 @@
+/*
+ * (C) Copyright 2015
+ * Texas Instruments Incorporated, <www.ti.com>
+ *
+ * Lokesh Vutla <lokeshvutla@ti.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/utils.h>
+#include <asm/arch/dra7xx_iodelay.h>
+#include <asm/arch/omap.h>
+#include <asm/arch/sys_proto.h>
+#include <asm/arch/clock.h>
+#include <asm/omap_common.h>
+
+static int isolate_io(u32 isolate)
+{
+	if (isolate) {
+		clrsetbits_le32((*ctrl)->control_pbias, SDCARD_PWRDNZ,
+				SDCARD_PWRDNZ);
+		clrsetbits_le32((*ctrl)->control_pbias, SDCARD_BIAS_PWRDNZ,
+				SDCARD_BIAS_PWRDNZ);
+	}
+
+	/* Override control on ISOCLKIN signal to IO pad ring. */
+	clrsetbits_le32((*prcm)->prm_io_pmctrl, PMCTRL_ISOCLK_OVERRIDE_MASK,
+			PMCTRL_ISOCLK_OVERRIDE_CTRL);
+	if (!wait_on_value(PMCTRL_ISOCLK_STATUS_MASK, PMCTRL_ISOCLK_STATUS_MASK,
+			   (u32 *)(*prcm)->prm_io_pmctrl, LDELAY))
+		return ERR_DEISOLATE_IO << isolate;
+
+	/* Isolate/Deisolate IO */
+	clrsetbits_le32((*ctrl)->ctrl_core_sma_sw_0, CTRL_ISOLATE_MASK,
+			isolate << CTRL_ISOLATE_SHIFT);
+	/* Dummy read to add delay t > 10ns */
+	readl((*ctrl)->ctrl_core_sma_sw_0);
+
+	/* Return control on ISOCLKIN to hardware */
+	clrsetbits_le32((*prcm)->prm_io_pmctrl, PMCTRL_ISOCLK_OVERRIDE_MASK,
+			PMCTRL_ISOCLK_NOT_OVERRIDE_CTRL);
+	if (!wait_on_value(PMCTRL_ISOCLK_STATUS_MASK,
+			   0 << PMCTRL_ISOCLK_STATUS_SHIFT,
+			   (u32 *)(*prcm)->prm_io_pmctrl, LDELAY))
+		return ERR_DEISOLATE_IO << isolate;
+
+	return 0;
+}
+
+static int calibrate_iodelay(u32 base)
+{
+	u32 reg;
+
+	/* Configure REFCLK period */
+	reg = readl(base + CFG_REG_2_OFFSET);
+	reg &= ~CFG_REG_REFCLK_PERIOD_MASK;
+	reg |= CFG_REG_REFCLK_PERIOD;
+	writel(reg, base + CFG_REG_2_OFFSET);
+
+	/* Initiate Calibration */
+	clrsetbits_le32(base + CFG_REG_0_OFFSET, CFG_REG_CALIB_STRT_MASK,
+			CFG_REG_CALIB_STRT << CFG_REG_CALIB_STRT_SHIFT);
+	if (!wait_on_value(CFG_REG_CALIB_STRT_MASK, CFG_REG_CALIB_END,
+			   (u32 *)(base + CFG_REG_0_OFFSET), LDELAY))
+		return ERR_CALIBRATE_IODELAY;
+
+	return 0;
+}
+
+static int update_delay_mechanism(u32 base)
+{
+	/* Initiate the reload of calibrated values. */
+	clrsetbits_le32(base + CFG_REG_0_OFFSET, CFG_REG_ROM_READ_MASK,
+			CFG_REG_ROM_READ_START);
+	if (!wait_on_value(CFG_REG_ROM_READ_MASK, CFG_REG_ROM_READ_END,
+			   (u32 *)(base + CFG_REG_0_OFFSET), LDELAY))
+		return ERR_UPDATE_DELAY;
+
+	return 0;
+}
+
+void __recalibrate_iodelay(struct pad_conf_entry const *pad, int npads)
+{
+	int ret = 0;
+
+	/* IO recalibration should be done only from SRAM */
+	if (OMAP_INIT_CONTEXT_SPL != omap_hw_init_context()) {
+		puts("IODELAY recalibration called from invalid context - use only from SPL in SRAM\n");
+		return;
+	}
+
+	/* unlock IODELAY CONFIG registers */
+	writel(CFG_IODELAY_UNLOCK_KEY, (*ctrl)->iodelay_config_base +
+	       CFG_REG_8_OFFSET);
+
+	ret = calibrate_iodelay((*ctrl)->iodelay_config_base);
+	if (ret)
+		goto err;
+
+	ret = isolate_io(ISOLATE_IO);
+	if (ret)
+		goto err;
+
+	ret = update_delay_mechanism((*ctrl)->iodelay_config_base);
+	if (ret)
+		goto err;
+
+	/* Configure Mux settings */
+	do_set_mux32((*ctrl)->control_padconf_core_base, pad, npads);
+
+	ret = isolate_io(DEISOLATE_IO);
+
+err:
+	/* lock IODELAY CONFIG registers */
+	writel(CFG_IODELAY_LOCK_KEY, (*ctrl)->iodelay_config_base +
+	       CFG_REG_8_OFFSET);
+	/*
+	 * UART cannot be used during IO recalibration sequence as IOs are in
+	 * isolation. So error handling and debug prints are done after
+	 * complete IO delay recalibration sequence
+	 */
+	switch (ret) {
+	case ERR_CALIBRATE_IODELAY:
+		puts("IODELAY: IO delay calibration sequence failed\n");
+		break;
+	case ERR_ISOLATE_IO:
+		puts("IODELAY: Isolation of Device IOs failed\n");
+		break;
+	case ERR_UPDATE_DELAY:
+		puts("IODELAY: Delay mechanism update with new calibrated values failed\n");
+		break;
+	case ERR_DEISOLATE_IO:
+		puts("IODELAY: De-isolation of Device IOs failed\n");
+		break;
+	default:
+		debug("IODELAY: IO delay recalibration successfully completed\n");
+	}
+}