1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-cns3xxx.c b/drivers/mmc/host/sdhci-cns3xxx.c
new file mode 100644
index 000000000..2a29c7a4f
--- /dev/null
+++ b/drivers/mmc/host/sdhci-cns3xxx.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SDHCI support for CNS3xxx SoC
+ *
+ * Copyright 2008 Cavium Networks
+ * Copyright 2010 MontaVista Software, LLC.
+ *
+ * Authors: Scott Shu
+ *	    Anton Vorontsov <avorontsov@mvista.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/mmc/host.h>
+#include <linux/module.h>
+#include "sdhci-pltfm.h"
+
+static unsigned int sdhci_cns3xxx_get_max_clk(struct sdhci_host *host)
+{
+	return 150000000;
+}
+
+static void sdhci_cns3xxx_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+	struct device *dev = mmc_dev(host->mmc);
+	int div = 1;
+	u16 clk;
+	unsigned long timeout;
+
+	host->mmc->actual_clock = 0;
+
+	sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
+
+	if (clock == 0)
+		return;
+
+	while (host->max_clk / div > clock) {
+		/*
+		 * On CNS3xxx divider grows linearly up to 4, and then
+		 * exponentially up to 256.
+		 */
+		if (div < 4)
+			div += 1;
+		else if (div < 256)
+			div *= 2;
+		else
+			break;
+	}
+
+	dev_dbg(dev, "desired SD clock: %d, actual: %d\n",
+		clock, host->max_clk / div);
+
+	/* Divide by 3 is special. */
+	if (div != 3)
+		div >>= 1;
+
+	clk = div << SDHCI_DIVIDER_SHIFT;
+	clk |= SDHCI_CLOCK_INT_EN;
+	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+	timeout = 20;
+	while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
+			& SDHCI_CLOCK_INT_STABLE)) {
+		if (timeout == 0) {
+			dev_warn(dev, "clock is unstable");
+			break;
+		}
+		timeout--;
+		mdelay(1);
+	}
+
+	clk |= SDHCI_CLOCK_CARD_EN;
+	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+}
+
+static const struct sdhci_ops sdhci_cns3xxx_ops = {
+	.get_max_clock	= sdhci_cns3xxx_get_max_clk,
+	.set_clock	= sdhci_cns3xxx_set_clock,
+	.set_bus_width	= sdhci_set_bus_width,
+	.reset          = sdhci_reset,
+	.set_uhs_signaling = sdhci_set_uhs_signaling,
+};
+
+static const struct sdhci_pltfm_data sdhci_cns3xxx_pdata = {
+	.ops = &sdhci_cns3xxx_ops,
+	.quirks = SDHCI_QUIRK_BROKEN_DMA |
+		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
+		  SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
+		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
+		  SDHCI_QUIRK_BROKEN_TIMEOUT_VAL,
+};
+
+static int sdhci_cns3xxx_probe(struct platform_device *pdev)
+{
+	return sdhci_pltfm_register(pdev, &sdhci_cns3xxx_pdata, 0);
+}
+
+static struct platform_driver sdhci_cns3xxx_driver = {
+	.driver		= {
+		.name	= "sdhci-cns3xxx",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.pm	= &sdhci_pltfm_pmops,
+	},
+	.probe		= sdhci_cns3xxx_probe,
+	.remove		= sdhci_pltfm_unregister,
+};
+
+module_platform_driver(sdhci_cns3xxx_driver);
+
+MODULE_DESCRIPTION("SDHCI driver for CNS3xxx");
+MODULE_AUTHOR("Scott Shu, "
+	      "Anton Vorontsov <avorontsov@mvista.com>");
+MODULE_LICENSE("GPL v2");