mmc: Add OpenFirmware bindings for SDHCI driver

This patch adds a new driver: sdhci-of. The driver is similar to
the sdhci-pci, it contains common probe code, and controller-specific
ops and quirks.

So far there are only Freescale eSDHC ops and quirks.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

3 files changed, 321 insertions, 0 deletions

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index e8a7b50a01e7..126a0da095e4 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -72,6 +72,17 @@ config MMC_RICOH_MMC
 
           If unsure, say Y.
 
+config MMC_SDHCI_OF
+        tristate "SDHCI support on OpenFirmware platforms"
+        depends on MMC_SDHCI && PPC_OF
+        select MMC_SDHCI_IO_ACCESSORS
+        help
+          This selects the OF support for Secure Digital Host Controller
+          Interfaces. So far, only the Freescale eSDHC controller is known
+          to exist on OF platforms.
+
+          If unsure, say N.
+
 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 c006eb47e592..970a997620e1 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_MMC_MXC)		+= mxcmmc.o
 obj-$(CONFIG_MMC_SDHCI)         += sdhci.o
 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_WBSD)          += wbsd.o
 obj-$(CONFIG_MMC_AU1X)          += au1xmmc.o
 obj-$(CONFIG_MMC_OMAP)          += omap.o
diff --git a/drivers/mmc/host/sdhci-of.c b/drivers/mmc/host/sdhci-of.c
new file mode 100644
index 000000000000..3ff4ac3abe8b
--- /dev/null
+++ b/drivers/mmc/host/sdhci-of.c
@@ -0,0 +1,309 @@
+/*
+ * OpenFirmware bindings for Secure Digital Host Controller Interface.
+ *
+ * Copyright (c) 2007 Freescale Semiconductor, Inc.
+ * Copyright (c) 2009 MontaVista Software, Inc.
+ *
+ * Authors: Xiaobo Xie <X.Xie@freescale.com>
+ *          Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/mmc/host.h>
+#include "sdhci.h"
+
+struct sdhci_of_data {
+        unsigned int quirks;
+        struct sdhci_ops ops;
+};
+
+struct sdhci_of_host {
+        unsigned int clock;
+        u16 xfer_mode_shadow;
+};
+
+/*
+ * Ops and quirks for the Freescale eSDHC controller.
+ */
+
+#define ESDHC_DMA_SYSCTL        0x40c
+#define ESDHC_DMA_SNOOP         0x00000040
+
+#define ESDHC_SYSTEM_CONTROL    0x2c
+#define ESDHC_CLOCK_MASK        0x0000fff0
+#define ESDHC_PREDIV_SHIFT      8
+#define ESDHC_DIVIDER_SHIFT     4
+#define ESDHC_CLOCK_PEREN       0x00000004
+#define ESDHC_CLOCK_HCKEN       0x00000002
+#define ESDHC_CLOCK_IPGEN       0x00000001
+
+static u32 esdhc_readl(struct sdhci_host *host, int reg)
+{
+        return in_be32(host->ioaddr + reg);
+}
+
+static u16 esdhc_readw(struct sdhci_host *host, int reg)
+{
+        return in_be16(host->ioaddr + (reg ^ 0x2));
+}
+
+static u8 esdhc_readb(struct sdhci_host *host, int reg)
+{
+        return in_8(host->ioaddr + (reg ^ 0x3));
+}
+
+static void esdhc_writel(struct sdhci_host *host, u32 val, int reg)
+{
+        out_be32(host->ioaddr + reg, val);
+}
+
+static void esdhc_writew(struct sdhci_host *host, u16 val, int reg)
+{
+        struct sdhci_of_host *of_host = sdhci_priv(host);
+        int base = reg & ~0x3;
+        int shift = (reg & 0x2) * 8;
+
+        switch (reg) {
+        case SDHCI_TRANSFER_MODE:
+                /*
+                 * Postpone this write, we must do it together with a
+                 * command write that is down below.
+                 */
+                of_host->xfer_mode_shadow = val;
+                return;
+        case SDHCI_COMMAND:
+                esdhc_writel(host, val << 16 | of_host->xfer_mode_shadow,
+                             SDHCI_TRANSFER_MODE);
+                return;
+        case SDHCI_BLOCK_SIZE:
+                /*
+                 * Two last DMA bits are reserved, and first one is used for
+                 * non-standard blksz of 4096 bytes that we don't support
+                 * yet. So clear the DMA boundary bits.
+                 */
+                val &= ~SDHCI_MAKE_BLKSZ(0x7, 0);
+                /* fall through */
+        }
+        clrsetbits_be32(host->ioaddr + base, 0xffff << shift, val << shift);
+}
+
+static void esdhc_writeb(struct sdhci_host *host, u8 val, int reg)
+{
+        int base = reg & ~0x3;
+        int shift = (reg & 0x3) * 8;
+
+        clrsetbits_be32(host->ioaddr + base , 0xff << shift, val << shift);
+}
+
+static void esdhc_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+        int div;
+        int pre_div = 2;
+
+        clrbits32(host->ioaddr + ESDHC_SYSTEM_CONTROL, ESDHC_CLOCK_IPGEN |
+                  ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN | ESDHC_CLOCK_MASK);
+
+        if (clock == 0)
+                goto out;
+
+        if (host->max_clk / 16 > clock) {
+                for (; pre_div < 256; pre_div *= 2) {
+                        if (host->max_clk / pre_div < clock * 16)
+                                break;
+                }
+        }
+
+        for (div = 1; div <= 16; div++) {
+                if (host->max_clk / (div * pre_div) <= clock)
+                        break;
+        }
+
+        pre_div >>= 1;
+
+        setbits32(host->ioaddr + ESDHC_SYSTEM_CONTROL, ESDHC_CLOCK_IPGEN |
+                  ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN |
+                  div << ESDHC_DIVIDER_SHIFT | pre_div << ESDHC_PREDIV_SHIFT);
+        mdelay(100);
+out:
+        host->clock = clock;
+}
+
+static int esdhc_enable_dma(struct sdhci_host *host)
+{
+        setbits32(host->ioaddr + ESDHC_DMA_SYSCTL, ESDHC_DMA_SNOOP);
+        return 0;
+}
+
+static unsigned int esdhc_get_max_clock(struct sdhci_host *host)
+{
+        struct sdhci_of_host *of_host = sdhci_priv(host);
+
+        return of_host->clock;
+}
+
+static unsigned int esdhc_get_timeout_clock(struct sdhci_host *host)
+{
+        struct sdhci_of_host *of_host = sdhci_priv(host);
+
+        return of_host->clock / 1000;
+}
+
+static struct sdhci_of_data sdhci_esdhc = {
+        .quirks = SDHCI_QUIRK_FORCE_BLK_SZ_2048 |
+                  SDHCI_QUIRK_BROKEN_CARD_DETECTION |
+                  SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
+                  SDHCI_QUIRK_NO_BUSY_IRQ |
+                  SDHCI_QUIRK_NONSTANDARD_CLOCK |
+                  SDHCI_QUIRK_PIO_NEEDS_DELAY |
+                  SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET |
+                  SDHCI_QUIRK_NO_CARD_NO_RESET,
+        .ops = {
+                .readl = esdhc_readl,
+                .readw = esdhc_readw,
+                .readb = esdhc_readb,
+                .writel = esdhc_writel,
+                .writew = esdhc_writew,
+                .writeb = esdhc_writeb,
+                .set_clock = esdhc_set_clock,
+                .enable_dma = esdhc_enable_dma,
+                .get_max_clock = esdhc_get_max_clock,
+                .get_timeout_clock = esdhc_get_timeout_clock,
+        },
+};
+
+#ifdef CONFIG_PM
+
+static int sdhci_of_suspend(struct of_device *ofdev, pm_message_t state)
+{
+        struct sdhci_host *host = dev_get_drvdata(&ofdev->dev);
+
+        return mmc_suspend_host(host->mmc, state);
+}
+
+static int sdhci_of_resume(struct of_device *ofdev)
+{
+        struct sdhci_host *host = dev_get_drvdata(&ofdev->dev);
+
+        return mmc_resume_host(host->mmc);
+}
+
+#else
+
+#define sdhci_of_suspend NULL
+#define sdhci_of_resume NULL
+
+#endif
+
+static int __devinit sdhci_of_probe(struct of_device *ofdev,
+                                 const struct of_device_id *match)
+{
+        struct device_node *np = ofdev->node;
+        struct sdhci_of_data *sdhci_of_data = match->data;
+        struct sdhci_host *host;
+        struct sdhci_of_host *of_host;
+        const u32 *clk;
+        int size;
+        int ret;
+
+        if (!of_device_is_available(np))
+                return -ENODEV;
+
+        host = sdhci_alloc_host(&ofdev->dev, sizeof(*of_host));
+        if (!host)
+                return -ENOMEM;
+
+        of_host = sdhci_priv(host);
+        dev_set_drvdata(&ofdev->dev, host);
+
+        host->ioaddr = of_iomap(np, 0);
+        if (!host->ioaddr) {
+                ret = -ENOMEM;
+                goto err_addr_map;
+        }
+
+        host->irq = irq_of_parse_and_map(np, 0);
+        if (!host->irq) {
+                ret = -EINVAL;
+                goto err_no_irq;
+        }
+
+        host->hw_name = dev_name(&ofdev->dev);
+        if (sdhci_of_data) {
+                host->quirks = sdhci_of_data->quirks;
+                host->ops = &sdhci_of_data->ops;
+        }
+
+        clk = of_get_property(np, "clock-frequency", &size);
+        if (clk && size == sizeof(*clk) && *clk)
+                of_host->clock = *clk;
+
+        ret = sdhci_add_host(host);
+        if (ret)
+                goto err_add_host;
+
+        return 0;
+
+err_add_host:
+        irq_dispose_mapping(host->irq);
+err_no_irq:
+        iounmap(host->ioaddr);
+err_addr_map:
+        sdhci_free_host(host);
+        return ret;
+}
+
+static int __devexit sdhci_of_remove(struct of_device *ofdev)
+{
+        struct sdhci_host *host = dev_get_drvdata(&ofdev->dev);
+
+        sdhci_remove_host(host, 0);
+        sdhci_free_host(host);
+        irq_dispose_mapping(host->irq);
+        iounmap(host->ioaddr);
+        return 0;
+}
+
+static const struct of_device_id sdhci_of_match[] = {
+        { .compatible = "fsl,mpc8379-esdhc", .data = &sdhci_esdhc, },
+        { .compatible = "fsl,mpc8536-esdhc", .data = &sdhci_esdhc, },
+        { .compatible = "generic-sdhci", },
+        {},
+};
+MODULE_DEVICE_TABLE(of, sdhci_of_match);
+
+static struct of_platform_driver sdhci_of_driver = {
+        .driver.name = "sdhci-of",
+        .match_table = sdhci_of_match,
+        .probe = sdhci_of_probe,
+        .remove = __devexit_p(sdhci_of_remove),
+        .suspend = sdhci_of_suspend,
+        .resume = sdhci_of_resume,
+};
+
+static int __init sdhci_of_init(void)
+{
+        return of_register_platform_driver(&sdhci_of_driver);
+}
+module_init(sdhci_of_init);
+
+static void __exit sdhci_of_exit(void)
+{
+        of_unregister_platform_driver(&sdhci_of_driver);
+}
+module_exit(sdhci_of_exit);
+
+MODULE_DESCRIPTION("Secure Digital Host Controller Interface OF driver");
+MODULE_AUTHOR("Xiaobo Xie <X.Xie@freescale.com>, "
+              "Anton Vorontsov <avorontsov@ru.mvista.com>");
+MODULE_LICENSE("GPL");