sdhci-pltfm: add support for CNS3xxx SoC devices

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

Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
Cc: Ben Dooks <ben@simtec.co.uk>
Cc: Richard R?jfors <richard.rojfors@pelagicore.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 97 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci-cns3xxx.c b/drivers/mmc/host/sdhci-cns3xxx.c
new file mode 100644
index 000000000000..b7050b380d5f
--- /dev/null
+++ b/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 <avorontsov@mvista.com>
+ *
+ * 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,
+};