1 files changed, 129 insertions, 0 deletions
diff --git a/drivers/mmc/host/dw_mmc-starfive.c b/drivers/mmc/host/dw_mmc-starfive.c
new file mode 100644
index 000000000000..34964b0dab21
--- /dev/null
+++ b/drivers/mmc/host/dw_mmc-starfive.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * StarFive Designware Mobile Storage Host Controller Driver
+ *
+ * Copyright (c) 2022 StarFive Technology Co., Ltd.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mmc/host.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "dw_mmc.h"
+#include "dw_mmc-pltfm.h"
+
+#define ALL_INT_CLR		0x1ffff
+#define MAX_DELAY_CHAIN		32
+
+#define STARFIVE_SMPL_PHASE     GENMASK(20, 16)
+
+static void dw_mci_starfive_set_ios(struct dw_mci *host, struct mmc_ios *ios)
+{
+	int ret;
+	unsigned int clock;
+
+	if (ios->timing == MMC_TIMING_MMC_DDR52 || ios->timing == MMC_TIMING_UHS_DDR50) {
+		clock = (ios->clock > 50000000 && ios->clock <= 52000000) ? 100000000 : ios->clock;
+		ret = clk_set_rate(host->ciu_clk, clock);
+		if (ret)
+			dev_dbg(host->dev, "Use an external frequency divider %uHz\n", ios->clock);
+		host->bus_hz = clk_get_rate(host->ciu_clk);
+	} else {
+		dev_dbg(host->dev, "Using the internal divider\n");
+	}
+}
+
+static void dw_mci_starfive_set_sample_phase(struct dw_mci *host, u32 smpl_phase)
+{
+	/* change driver phase and sample phase */
+	u32 reg_value = mci_readl(host, UHS_REG_EXT);
+
+	/* In UHS_REG_EXT, only 5 bits valid in DRV_PHASE and SMPL_PHASE */
+	reg_value &= ~STARFIVE_SMPL_PHASE;
+	reg_value |= FIELD_PREP(STARFIVE_SMPL_PHASE, smpl_phase);
+	mci_writel(host, UHS_REG_EXT, reg_value);
+
+	/* We should delay 1ms wait for timing setting finished. */
+	mdelay(1);
+}
+
+static int dw_mci_starfive_execute_tuning(struct dw_mci_slot *slot,
+					     u32 opcode)
+{
+	static const int grade  = MAX_DELAY_CHAIN;
+	struct dw_mci *host = slot->host;
+	int smpl_phase, smpl_raise = -1, smpl_fall = -1;
+	int ret;
+
+	for (smpl_phase = 0; smpl_phase < grade; smpl_phase++) {
+		dw_mci_starfive_set_sample_phase(host, smpl_phase);
+		mci_writel(host, RINTSTS, ALL_INT_CLR);
+
+		ret = mmc_send_tuning(slot->mmc, opcode, NULL);
+
+		if (!ret && smpl_raise < 0) {
+			smpl_raise = smpl_phase;
+		} else if (ret && smpl_raise >= 0) {
+			smpl_fall = smpl_phase - 1;
+			break;
+		}
+	}
+
+	if (smpl_phase >= grade)
+		smpl_fall = grade - 1;
+
+	if (smpl_raise < 0) {
+		smpl_phase = 0;
+		dev_err(host->dev, "No valid delay chain! use default\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	smpl_phase = (smpl_raise + smpl_fall) / 2;
+	dev_dbg(host->dev, "Found valid delay chain! use it [delay=%d]\n", smpl_phase);
+	ret = 0;
+
+out:
+	dw_mci_starfive_set_sample_phase(host, smpl_phase);
+	mci_writel(host, RINTSTS, ALL_INT_CLR);
+	return ret;
+}
+
+static const struct dw_mci_drv_data starfive_data = {
+	.common_caps		= MMC_CAP_CMD23,
+	.set_ios		= dw_mci_starfive_set_ios,
+	.execute_tuning		= dw_mci_starfive_execute_tuning,
+};
+
+static const struct of_device_id dw_mci_starfive_match[] = {
+	{ .compatible = "starfive,jh7110-mmc",
+		.data = &starfive_data },
+	{},
+};
+MODULE_DEVICE_TABLE(of, dw_mci_starfive_match);
+
+static int dw_mci_starfive_probe(struct platform_device *pdev)
+{
+	return dw_mci_pltfm_register(pdev, &starfive_data);
+}
+
+static struct platform_driver dw_mci_starfive_driver = {
+	.probe = dw_mci_starfive_probe,
+	.remove = dw_mci_pltfm_remove,
+	.driver = {
+		.name = "dwmmc_starfive",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = dw_mci_starfive_match,
+	},
+};
+module_platform_driver(dw_mci_starfive_driver);
+
+MODULE_DESCRIPTION("StarFive JH7110 Specific DW-MSHC Driver Extension");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:dwmmc_starfive");