3 files changed, 451 insertions, 0 deletions

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 40111a6d8d5b..760992204a5e 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -94,6 +94,31 @@ config MMC_SDHCI_PLTFM
 
           If unsure, say N.
 
+config MMC_SDHCI_S3C
+        tristate "SDHCI support on Samsung S3C SoC"
+        depends on MMC_SDHCI && (PLAT_S3C24XX || PLAT_S3C64XX)
+        help
+          This selects the Secure Digital Host Controller Interface (SDHCI)
+          often referrered to as the HSMMC block in some of the Samsung S3C
+          range of SoC.
+
+          Note, due to the problems with DMA, the DMA support is only
+          available with CONFIG_EXPERIMENTAL is selected.
+
+          If you have a controller with this interface, say Y or M here.
+
+          If unsure, say N.
+
+config MMC_SDHCI_S3C_DMA
+        bool "DMA support on S3C SDHCI"
+        depends on MMC_SDHCI_S3C && EXPERIMENTAL
+        help
+          Enable DMA support on the Samsung S3C SDHCI glue. The DMA
+          has proved to be problematic if the controller encounters
+          certain errors, and thus should be treated with care.
+
+          YMMV.
+
 config MMC_OMAP
         tristate "TI OMAP Multimedia Card Interface support"
         depends on ARCH_OMAP
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 79da397c5fea..e637f2fa9bbd 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_MMC_SDHCI_PCI)	+= sdhci-pci.o
 obj-$(CONFIG_MMC_RICOH_MMC)     += ricoh_mmc.o
 obj-$(CONFIG_MMC_SDHCI_OF)      += sdhci-of.o
 obj-$(CONFIG_MMC_SDHCI_PLTFM)   += sdhci-pltfm.o
+obj-$(CONFIG_MMC_SDHCI_S3C)     += sdhci-s3c.o
 obj-$(CONFIG_MMC_WBSD)          += wbsd.o
 obj-$(CONFIG_MMC_AU1X)          += au1xmmc.o
 obj-$(CONFIG_MMC_OMAP)          += omap.o
diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
new file mode 100644
index 000000000000..19246fe3d3e2
--- /dev/null
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -0,0 +1,425 @@
+/* linux/drivers/mmc/host/sdhci-s3c.c
+ *
+ * Copyright 2008 Openmoko Inc.
+ * Copyright 2008 Simtec Electronics
+ *      Ben Dooks <ben@simtec.co.uk>
+ *      http://armlinux.simtec.co.uk/
+ *
+ * SDHCI (HSMMC) support for Samsung SoC
+ *
+ * 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/dma-mapping.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <linux/mmc/host.h>
+
+#include <plat/sdhci.h>
+#include <plat/regs-sdhci.h>
+
+#include "sdhci.h"
+
+#define MAX_BUS_CLK     (4)
+
+/**
+ * struct sdhci_s3c - S3C SDHCI instance
+ * @host: The SDHCI host created
+ * @pdev: The platform device we where created from.
+ * @ioarea: The resource created when we claimed the IO area.
+ * @pdata: The platform data for this controller.
+ * @cur_clk: The index of the current bus clock.
+ * @clk_io: The clock for the internal bus interface.
+ * @clk_bus: The clocks that are available for the SD/MMC bus clock.
+ */
+struct sdhci_s3c {
+        struct sdhci_host       *host;
+        struct platform_device  *pdev;
+        struct resource         *ioarea;
+        struct s3c_sdhci_platdata *pdata;
+        unsigned int            cur_clk;
+
+        struct clk              *clk_io;
+        struct clk              *clk_bus[MAX_BUS_CLK];
+};
+
+static inline struct sdhci_s3c *to_s3c(struct sdhci_host *host)
+{
+        return sdhci_priv(host);
+}
+
+/**
+ * get_curclk - convert ctrl2 register to clock source number
+ * @ctrl2: Control2 register value.
+ */
+static u32 get_curclk(u32 ctrl2)
+{
+        ctrl2 &= S3C_SDHCI_CTRL2_SELBASECLK_MASK;
+        ctrl2 >>= S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
+
+        return ctrl2;
+}
+
+static void sdhci_s3c_check_sclk(struct sdhci_host *host)
+{
+        struct sdhci_s3c *ourhost = to_s3c(host);
+        u32 tmp = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
+
+        if (get_curclk(tmp) != ourhost->cur_clk) {
+                dev_dbg(&ourhost->pdev->dev, "restored ctrl2 clock setting\n");
+
+                tmp &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
+                tmp |= ourhost->cur_clk << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
+                writel(tmp, host->ioaddr + 0x80);
+        }
+}
+
+/**
+ * sdhci_s3c_get_max_clk - callback to get maximum clock frequency.
+ * @host: The SDHCI host instance.
+ *
+ * Callback to return the maximum clock rate acheivable by the controller.
+*/
+static unsigned int sdhci_s3c_get_max_clk(struct sdhci_host *host)
+{
+        struct sdhci_s3c *ourhost = to_s3c(host);
+        struct clk *busclk;
+        unsigned int rate, max;
+        int clk;
+
+        /* note, a reset will reset the clock source */
+
+        sdhci_s3c_check_sclk(host);
+
+        for (max = 0, clk = 0; clk < MAX_BUS_CLK; clk++) {
+                busclk = ourhost->clk_bus[clk];
+                if (!busclk)
+                        continue;
+
+                rate = clk_get_rate(busclk);
+                if (rate > max)
+                        max = rate;
+        }
+
+        return max;
+}
+
+static unsigned int sdhci_s3c_get_timeout_clk(struct sdhci_host *host)
+{
+        return sdhci_s3c_get_max_clk(host) / 1000000;
+}
+
+/**
+ * sdhci_s3c_consider_clock - consider one the bus clocks for current setting
+ * @ourhost: Our SDHCI instance.
+ * @src: The source clock index.
+ * @wanted: The clock frequency wanted.
+ */
+static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
+                                             unsigned int src,
+                                             unsigned int wanted)
+{
+        unsigned long rate;
+        struct clk *clksrc = ourhost->clk_bus[src];
+        int div;
+
+        if (!clksrc)
+                return UINT_MAX;
+
+        rate = clk_get_rate(clksrc);
+
+        for (div = 1; div < 256; div *= 2) {
+                if ((rate / div) <= wanted)
+                        break;
+        }
+
+        dev_dbg(&ourhost->pdev->dev, "clk %d: rate %ld, want %d, got %ld\n",
+                src, rate, wanted, rate / div);
+
+        return (wanted - (rate / div));
+}
+
+/**
+ * sdhci_s3c_set_clock - callback on clock change
+ * @host: The SDHCI host being changed
+ * @clock: The clock rate being requested.
+ *
+ * When the card's clock is going to be changed, look at the new frequency
+ * and find the best clock source to go with it.
+*/
+static void sdhci_s3c_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+        struct sdhci_s3c *ourhost = to_s3c(host);
+        unsigned int best = UINT_MAX;
+        unsigned int delta;
+        int best_src = 0;
+        int src;
+        u32 ctrl;
+
+        /* don't bother if the clock is going off. */
+        if (clock == 0)
+                return;
+
+        for (src = 0; src < MAX_BUS_CLK; src++) {
+                delta = sdhci_s3c_consider_clock(ourhost, src, clock);
+                if (delta < best) {
+                        best = delta;
+                        best_src = src;
+                }
+        }
+
+        dev_dbg(&ourhost->pdev->dev,
+                "selected source %d, clock %d, delta %d\n",
+                 best_src, clock, best);
+
+        /* select the new clock source */
+
+        if (ourhost->cur_clk != best_src) {
+                struct clk *clk = ourhost->clk_bus[best_src];
+
+                /* turn clock off to card before changing clock source */
+                writew(0, host->ioaddr + SDHCI_CLOCK_CONTROL);
+
+                ourhost->cur_clk = best_src;
+                host->max_clk = clk_get_rate(clk);
+                host->timeout_clk = sdhci_s3c_get_timeout_clk(host);
+
+                ctrl = readl(host->ioaddr + S3C_SDHCI_CONTROL2);
+                ctrl &= ~S3C_SDHCI_CTRL2_SELBASECLK_MASK;
+                ctrl |= best_src << S3C_SDHCI_CTRL2_SELBASECLK_SHIFT;
+                writel(ctrl, host->ioaddr + S3C_SDHCI_CONTROL2);
+        }
+
+        /* reconfigure the hardware for new clock rate */
+
+        {
+                struct mmc_ios ios;
+
+                ios.clock = clock;
+
+                if (ourhost->pdata->cfg_card)
+                        (ourhost->pdata->cfg_card)(ourhost->pdev, host->ioaddr,
+                                                   &ios, NULL);
+        }
+}
+
+static struct sdhci_ops sdhci_s3c_ops = {
+        .get_max_clock          = sdhci_s3c_get_max_clk,
+        .get_timeout_clock      = sdhci_s3c_get_timeout_clk,
+        .set_clock              = sdhci_s3c_set_clock,
+};
+
+static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
+{
+        struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
+        struct device *dev = &pdev->dev;
+        struct sdhci_host *host;
+        struct sdhci_s3c *sc;
+        struct resource *res;
+        int ret, irq, ptr, clks;
+
+        if (!pdata) {
+                dev_err(dev, "no device data specified\n");
+                return -ENOENT;
+        }
+
+        irq = platform_get_irq(pdev, 0);
+        if (irq < 0) {
+                dev_err(dev, "no irq specified\n");
+                return irq;
+        }
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res) {
+                dev_err(dev, "no memory specified\n");
+                return -ENOENT;
+        }
+
+        host = sdhci_alloc_host(dev, sizeof(struct sdhci_s3c));
+        if (IS_ERR(host)) {
+                dev_err(dev, "sdhci_alloc_host() failed\n");
+                return PTR_ERR(host);
+        }
+
+        sc = sdhci_priv(host);
+
+        sc->host = host;
+        sc->pdev = pdev;
+        sc->pdata = pdata;
+
+        platform_set_drvdata(pdev, host);
+
+        sc->clk_io = clk_get(dev, "hsmmc");
+        if (IS_ERR(sc->clk_io)) {
+                dev_err(dev, "failed to get io clock\n");
+                ret = PTR_ERR(sc->clk_io);
+                goto err_io_clk;
+        }
+
+        /* enable the local io clock and keep it running for the moment. */
+        clk_enable(sc->clk_io);
+
+        for (clks = 0, ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
+                struct clk *clk;
+                char *name = pdata->clocks[ptr];
+
+                if (name == NULL)
+                        continue;
+
+                clk = clk_get(dev, name);
+                if (IS_ERR(clk)) {
+                        dev_err(dev, "failed to get clock %s\n", name);
+                        continue;
+                }
+
+                clks++;
+                sc->clk_bus[ptr] = clk;
+                clk_enable(clk);
+
+                dev_info(dev, "clock source %d: %s (%ld Hz)\n",
+                         ptr, name, clk_get_rate(clk));
+        }
+
+        if (clks == 0) {
+                dev_err(dev, "failed to find any bus clocks\n");
+                ret = -ENOENT;
+                goto err_no_busclks;
+        }
+
+        sc->ioarea = request_mem_region(res->start, resource_size(res),
+                                        mmc_hostname(host->mmc));
+        if (!sc->ioarea) {
+                dev_err(dev, "failed to reserve register area\n");
+                ret = -ENXIO;
+                goto err_req_regs;
+        }
+
+        host->ioaddr = ioremap_nocache(res->start, resource_size(res));
+        if (!host->ioaddr) {
+                dev_err(dev, "failed to map registers\n");
+                ret = -ENXIO;
+                goto err_req_regs;
+        }
+
+        /* Ensure we have minimal gpio selected CMD/CLK/Detect */
+        if (pdata->cfg_gpio)
+                pdata->cfg_gpio(pdev, pdata->max_width);
+
+        host->hw_name = "samsung-hsmmc";
+        host->ops = &sdhci_s3c_ops;
+        host->quirks = 0;
+        host->irq = irq;
+
+        /* Setup quirks for the controller */
+
+        /* Currently with ADMA enabled we are getting some length
+         * interrupts that are not being dealt with, do disable
+         * ADMA until this is sorted out. */
+        host->quirks |= SDHCI_QUIRK_BROKEN_ADMA;
+        host->quirks |= SDHCI_QUIRK_32BIT_ADMA_SIZE;
+
+#ifndef CONFIG_MMC_SDHCI_S3C_DMA
+
+        /* we currently see overruns on errors, so disable the SDMA
+         * support as well. */
+        host->quirks |= SDHCI_QUIRK_BROKEN_DMA;
+
+#endif /* CONFIG_MMC_SDHCI_S3C_DMA */
+
+        /* It seems we do not get an DATA transfer complete on non-busy
+         * transfers, not sure if this is a problem with this specific
+         * SDHCI block, or a missing configuration that needs to be set. */
+        host->quirks |= SDHCI_QUIRK_NO_BUSY_IRQ;
+
+        host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR |
+                         SDHCI_QUIRK_32BIT_DMA_SIZE);
+
+        ret = sdhci_add_host(host);
+        if (ret) {
+                dev_err(dev, "sdhci_add_host() failed\n");
+                goto err_add_host;
+        }
+
+        return 0;
+
+ err_add_host:
+        release_resource(sc->ioarea);
+        kfree(sc->ioarea);
+
+ err_req_regs:
+        for (ptr = 0; ptr < MAX_BUS_CLK; ptr++) {
+                clk_disable(sc->clk_bus[ptr]);
+                clk_put(sc->clk_bus[ptr]);
+        }
+
+ err_no_busclks:
+        clk_disable(sc->clk_io);
+        clk_put(sc->clk_io);
+
+ err_io_clk:
+        sdhci_free_host(host);
+
+        return ret;
+}
+
+static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
+{
+        return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int sdhci_s3c_suspend(struct platform_device *dev, pm_message_t pm)
+{
+        struct sdhci_host *host = platform_get_drvdata(dev);
+
+        sdhci_suspend_host(host, pm);
+        return 0;
+}
+
+static int sdhci_s3c_resume(struct platform_device *dev)
+{
+        struct sdhci_host *host = platform_get_drvdata(dev);
+
+        sdhci_resume_host(host);
+        return 0;
+}
+
+#else
+#define sdhci_s3c_suspend NULL
+#define sdhci_s3c_resume NULL
+#endif
+
+static struct platform_driver sdhci_s3c_driver = {
+        .probe          = sdhci_s3c_probe,
+        .remove         = __devexit_p(sdhci_s3c_remove),
+        .suspend        = sdhci_s3c_suspend,
+        .resume         = sdhci_s3c_resume,
+        .driver         = {
+                .owner  = THIS_MODULE,
+                .name   = "s3c-sdhci",
+        },
+};
+
+static int __init sdhci_s3c_init(void)
+{
+        return platform_driver_register(&sdhci_s3c_driver);
+}
+
+static void __exit sdhci_s3c_exit(void)
+{
+        platform_driver_unregister(&sdhci_s3c_driver);
+}
+
+module_init(sdhci_s3c_init);
+module_exit(sdhci_s3c_exit);
+
+MODULE_DESCRIPTION("Samsung SDHCI (HSMMC) glue");
+MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:s3c-sdhci");