sdhci-pltfm: add support for CNS3xxx SoC devices

There's nothing special, just SoC-specific ops and quirks.

Signed-off-by: Anton Vorontsov <[email protected]>
Cc: Ben Dooks <[email protected]>
Cc: Richard R?jfors <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Anton Vorontsov

drivers/mmc/host/Kconfig

@@ -121,6 +121,15 @@ config MMC_SDHCI_PLTFM
 
 	  If unsure, say N.
 
+config MMC_SDHCI_CNS3XXX
+	bool "SDHCI support on the Cavium Networks CNS3xxx SoC"
+	depends on ARCH_CNS3XXX
+	depends on MMC_SDHCI_PLTFM
+	help
+	  This selects the SDHCI support for CNS3xxx System-on-Chip devices.
+
+	  If unsure, say N.
+
 config MMC_SDHCI_S3C
 	tristate "SDHCI support on Samsung S3C SoC"
 	depends on MMC_SDHCI && (PLAT_S3C24XX || PLAT_S3C64XX)

drivers/mmc/host/Makefile

@@ -39,6 +39,7 @@ obj-$(CONFIG_MMC_JZ4740)	+= jz4740_mmc.o
 
 obj-$(CONFIG_MMC_SDHCI_PLTFM)			+= sdhci-platform.o
 sdhci-platform-y				:= sdhci-pltfm.o
+sdhci-platform-$(CONFIG_MMC_SDHCI_CNS3XXX)	+= sdhci-cns3xxx.o
 
 obj-$(CONFIG_MMC_SDHCI_OF)	+= sdhci-of.o
 sdhci-of-y				:= sdhci-of-core.o

drivers/mmc/host/sdhci-cns3xxx.c

@@ -0,0 +1,97 @@
+/*
+ * SDHCI support for CNS3xxx SoC
+ *
+ * Copyright 2008 Cavium Networks
+ * Copyright 2010 MontaVista Software, LLC.
+ *
+ * Authors: Scott Shu
+ *	    Anton Vorontsov <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/mmc/host.h>
+#include <linux/sdhci-pltfm.h>
+#include <mach/cns3xxx.h>
+#include "sdhci.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;
+
+	if (clock == host->clock)
+		return;
+
+	sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
+
+	if (clock == 0)
+		goto out;
+
+	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);
+out:
+	host->clock = clock;
+}
+
+static struct sdhci_ops sdhci_cns3xxx_ops = {
+	.get_max_clock	= sdhci_cns3xxx_get_max_clk,
+	.set_clock	= sdhci_cns3xxx_set_clock,
+};
+
+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 |
+		  SDHCI_QUIRK_NONSTANDARD_CLOCK,
+};

drivers/mmc/host/sdhci-pltfm.c

@@ -158,6 +158,9 @@ static int __devexit sdhci_pltfm_remove(struct platform_device *pdev)
 
 static const struct platform_device_id sdhci_pltfm_ids[] = {
 	{ "sdhci", },
+#ifdef CONFIG_MMC_SDHCI_CNS3XXX
+	{ "sdhci-cns3xxx", (kernel_ulong_t)&sdhci_cns3xxx_pdata },
+#endif
 	{ },
 };
 MODULE_DEVICE_TABLE(platform, sdhci_pltfm_ids);

drivers/mmc/host/sdhci-pltfm.h

@@ -11,4 +11,8 @@
 #ifndef _DRIVERS_MMC_SDHCI_PLTFM_H
 #define _DRIVERS_MMC_SDHCI_PLTFM_H
 
+#include <linux/sdhci-pltfm.h>
+
+extern struct sdhci_pltfm_data sdhci_cns3xxx_pdata;
+
 #endif /* _DRIVERS_MMC_SDHCI_PLTFM_H */