mmc: bcm281xx SDHCI driver

Add SDHCI driver for the Broadcom 281xx SoCs.

Still missing:
 - power managemement

Signed-off-by: Christian Daudt <csd@broadcom.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

3 files changed, 360 insertions, 0 deletions

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 1be228998c81..8a4c066787d7 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -249,6 +249,17 @@ config MMC_SDHCI_S3C_DMA
 
           YMMV.
 
+config MMC_SDHCI_BCM_KONA
+        tristate "SDHCI support on Broadcom KONA platform"
+        depends on ARCH_BCM
+        select MMC_SDHCI_PLTFM
+        help
+          This selects the Broadcom Kona Secure Digital Host Controller
+          Interface(SDHCI) support.
+          This is used in Broadcom mobile SoCs.
+
+          If you have a controller with this interface, say Y or M here.
+
 config MMC_SDHCI_BCM2835
         tristate "SDHCI platform support for the BCM2835 SD/MMC Controller"
         depends on ARCH_BCM2835
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 67718c1b79ce..d422e2167e19 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_MMC_SDHCI_DOVE)		+= sdhci-dove.o
 obj-$(CONFIG_MMC_SDHCI_TEGRA)           += sdhci-tegra.o
 obj-$(CONFIG_MMC_SDHCI_OF_ESDHC)        += sdhci-of-esdhc.o
 obj-$(CONFIG_MMC_SDHCI_OF_HLWD)         += sdhci-of-hlwd.o
+obj-$(CONFIG_MMC_SDHCI_BCM_KONA)        += sdhci-bcm-kona.o
 obj-$(CONFIG_MMC_SDHCI_BCM2835)         += sdhci-bcm2835.o
 
 ifeq ($(CONFIG_CB710_DEBUG),y)
diff --git a/drivers/mmc/host/sdhci-bcm-kona.c b/drivers/mmc/host/sdhci-bcm-kona.c
new file mode 100644
index 000000000000..87175f9817c2
--- /dev/null
+++ b/drivers/mmc/host/sdhci-bcm-kona.c
@@ -0,0 +1,348 @@
+/*
+ * Copyright (C) 2013 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/highmem.h>
+#include <linux/platform_device.h>
+#include <linux/mmc/host.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/clk.h>
+#include <linux/regulator/consumer.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/version.h>
+#include <linux/mmc/slot-gpio.h>
+
+#include "sdhci-pltfm.h"
+#include "sdhci.h"
+
+#define SDHCI_SOFT_RESET                        0x01000000
+#define KONA_SDHOST_CORECTRL                    0x8000
+#define KONA_SDHOST_CD_PINCTRL                  0x00000008
+#define KONA_SDHOST_STOP_HCLK                   0x00000004
+#define KONA_SDHOST_RESET                       0x00000002
+#define KONA_SDHOST_EN                          0x00000001
+
+#define KONA_SDHOST_CORESTAT                    0x8004
+#define KONA_SDHOST_WP                          0x00000002
+#define KONA_SDHOST_CD_SW                       0x00000001
+
+#define KONA_SDHOST_COREIMR                     0x8008
+#define KONA_SDHOST_IP                          0x00000001
+
+#define KONA_SDHOST_COREISR                     0x800C
+#define KONA_SDHOST_COREIMSR                    0x8010
+#define KONA_SDHOST_COREDBG1                    0x8014
+#define KONA_SDHOST_COREGPO_MASK                0x8018
+
+#define SD_DETECT_GPIO_DEBOUNCE_128MS           128
+
+#define KONA_MMC_AUTOSUSPEND_DELAY              (50)
+
+struct sdhci_bcm_kona_dev {
+        struct mutex    write_lock; /* protect back to back writes */
+};
+
+
+static int sdhci_bcm_kona_sd_reset(struct sdhci_host *host)
+{
+        unsigned int val;
+        unsigned long timeout;
+
+        /* This timeout should be sufficent for core to reset */
+        timeout = jiffies + msecs_to_jiffies(100);
+
+        /* reset the host using the top level reset */
+        val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
+        val |= KONA_SDHOST_RESET;
+        sdhci_writel(host, val, KONA_SDHOST_CORECTRL);
+
+        while (!(sdhci_readl(host, KONA_SDHOST_CORECTRL) & KONA_SDHOST_RESET)) {
+                if (time_is_before_jiffies(timeout)) {
+                        pr_err("Error: sd host is stuck in reset!!!\n");
+                        return -EFAULT;
+                }
+        }
+
+        /* bring the host out of reset */
+        val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
+        val &= ~KONA_SDHOST_RESET;
+
+        /*
+         * Back-to-Back register write needs a delay of 1ms at bootup (min 10uS)
+         * Back-to-Back writes to same register needs delay when SD bus clock
+         * is very low w.r.t AHB clock, mainly during boot-time and during card
+         * insert-removal.
+         */
+        usleep_range(1000, 5000);
+        sdhci_writel(host, val, KONA_SDHOST_CORECTRL);
+
+        return 0;
+}
+
+static void sdhci_bcm_kona_sd_init(struct sdhci_host *host)
+{
+        unsigned int val;
+
+        /* enable the interrupt from the IP core */
+        val = sdhci_readl(host, KONA_SDHOST_COREIMR);
+        val |= KONA_SDHOST_IP;
+        sdhci_writel(host, val, KONA_SDHOST_COREIMR);
+
+        /* Enable the AHB clock gating module to the host */
+        val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
+        val |= KONA_SDHOST_EN;
+
+        /*
+         * Back-to-Back register write needs a delay of 1ms at bootup (min 10uS)
+         * Back-to-Back writes to same register needs delay when SD bus clock
+         * is very low w.r.t AHB clock, mainly during boot-time and during card
+         * insert-removal.
+         */
+        usleep_range(1000, 5000);
+        sdhci_writel(host, val, KONA_SDHOST_CORECTRL);
+}
+
+/*
+ * Software emulation of the SD card insertion/removal. Set insert=1 for insert
+ * and insert=0 for removal. The card detection is done by GPIO. For Broadcom
+ * IP to function properly the bit 0 of CORESTAT register needs to be set/reset
+ * to generate the CD IRQ handled in sdhci.c which schedules card_tasklet.
+ */
+static int sdhci_bcm_kona_sd_card_emulate(struct sdhci_host *host, int insert)
+{
+        struct sdhci_pltfm_host *pltfm_priv = sdhci_priv(host);
+        struct sdhci_bcm_kona_dev *kona_dev = sdhci_pltfm_priv(pltfm_priv);
+        u32 val;
+
+        /*
+         * Back-to-Back register write needs a delay of min 10uS.
+         * Back-to-Back writes to same register needs delay when SD bus clock
+         * is very low w.r.t AHB clock, mainly during boot-time and during card
+         * insert-removal.
+         * We keep 20uS
+         */
+        mutex_lock(&kona_dev->write_lock);
+        udelay(20);
+        val = sdhci_readl(host, KONA_SDHOST_CORESTAT);
+
+        if (insert) {
+                int ret;
+
+                ret = mmc_gpio_get_ro(host->mmc);
+                if (ret >= 0)
+                        val = (val & ~KONA_SDHOST_WP) |
+                                ((ret) ? KONA_SDHOST_WP : 0);
+
+                val |= KONA_SDHOST_CD_SW;
+                sdhci_writel(host, val, KONA_SDHOST_CORESTAT);
+        } else {
+                val &= ~KONA_SDHOST_CD_SW;
+                sdhci_writel(host, val, KONA_SDHOST_CORESTAT);
+        }
+        mutex_unlock(&kona_dev->write_lock);
+
+        return 0;
+}
+
+/*
+ * SD card interrupt event callback
+ */
+void sdhci_bcm_kona_card_event(struct sdhci_host *host)
+{
+        if (mmc_gpio_get_cd(host->mmc) > 0) {
+                dev_dbg(mmc_dev(host->mmc),
+                        "card inserted\n");
+                sdhci_bcm_kona_sd_card_emulate(host, 1);
+        } else {
+                dev_dbg(mmc_dev(host->mmc),
+                        "card removed\n");
+                sdhci_bcm_kona_sd_card_emulate(host, 0);
+        }
+}
+
+/*
+ * Get the base clock. Use central clock source for now. Not sure if different
+ * clock speed to each dev is allowed
+ */
+static unsigned int sdhci_bcm_kona_get_max_clk(struct sdhci_host *host)
+{
+        struct sdhci_bcm_kona_dev *kona_dev;
+        struct sdhci_pltfm_host *pltfm_priv = sdhci_priv(host);
+        kona_dev = sdhci_pltfm_priv(pltfm_priv);
+
+        return host->mmc->f_max;
+}
+
+static unsigned int sdhci_bcm_kona_get_timeout_clock(struct sdhci_host *host)
+{
+        return sdhci_bcm_kona_get_max_clk(host);
+}
+
+static void sdhci_bcm_kona_init_74_clocks(struct sdhci_host *host,
+                                u8 power_mode)
+{
+        /*
+         *  JEDEC and SD spec specify supplying 74 continuous clocks to
+         * device after power up. With minimum bus (100KHz) that
+         * that translates to 740us
+         */
+        if (power_mode != MMC_POWER_OFF)
+                udelay(740);
+}
+
+static struct sdhci_ops sdhci_bcm_kona_ops = {
+        .get_max_clock = sdhci_bcm_kona_get_max_clk,
+        .get_timeout_clock = sdhci_bcm_kona_get_timeout_clock,
+        .platform_send_init_74_clocks = sdhci_bcm_kona_init_74_clocks,
+        .card_event = sdhci_bcm_kona_card_event,
+};
+
+static struct sdhci_pltfm_data sdhci_pltfm_data_kona = {
+        .ops    = &sdhci_bcm_kona_ops,
+        .quirks = SDHCI_QUIRK_NO_CARD_NO_RESET |
+                SDHCI_QUIRK_BROKEN_TIMEOUT_VAL | SDHCI_QUIRK_32BIT_DMA_ADDR |
+                SDHCI_QUIRK_32BIT_DMA_SIZE | SDHCI_QUIRK_32BIT_ADMA_SIZE |
+                SDHCI_QUIRK_FORCE_BLK_SZ_2048 |
+                SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
+};
+
+static const struct of_device_id sdhci_bcm_kona_of_match[] __initdata = {
+        { .compatible = "bcm,kona-sdhci"},
+        {}
+};
+MODULE_DEVICE_TABLE(of, sdhci_bcm_kona_of_match);
+
+static int __init sdhci_bcm_kona_probe(struct platform_device *pdev)
+{
+        struct sdhci_bcm_kona_dev *kona_dev = NULL;
+        struct sdhci_pltfm_host *pltfm_priv;
+        struct device *dev = &pdev->dev;
+        struct sdhci_host *host;
+        int ret;
+
+        ret = 0;
+
+        host = sdhci_pltfm_init(pdev, &sdhci_pltfm_data_kona,
+                        sizeof(*kona_dev));
+        if (IS_ERR(host))
+                return PTR_ERR(host);
+
+        dev_dbg(dev, "%s: inited. IOADDR=%p\n", __func__, host->ioaddr);
+
+        pltfm_priv = sdhci_priv(host);
+
+        kona_dev = sdhci_pltfm_priv(pltfm_priv);
+        mutex_init(&kona_dev->write_lock);
+
+        mmc_of_parse(host->mmc);
+
+        if (!host->mmc->f_max) {
+                dev_err(&pdev->dev, "Missing max-freq for SDHCI cfg\n");
+                ret = -ENXIO;
+                goto err_pltfm_free;
+        }
+
+        dev_dbg(dev, "non-removable=%c\n",
+                (host->mmc->caps & MMC_CAP_NONREMOVABLE) ? 'Y' : 'N');
+        dev_dbg(dev, "cd_gpio %c, wp_gpio %c\n",
+                (mmc_gpio_get_cd(host->mmc) != -ENOSYS) ? 'Y' : 'N',
+                (mmc_gpio_get_ro(host->mmc) != -ENOSYS) ? 'Y' : 'N');
+
+        if (host->mmc->caps | MMC_CAP_NONREMOVABLE)
+                host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
+
+        dev_dbg(dev, "is_8bit=%c\n",
+                (host->mmc->caps | MMC_CAP_8_BIT_DATA) ? 'Y' : 'N');
+
+        ret = sdhci_bcm_kona_sd_reset(host);
+        if (ret)
+                goto err_pltfm_free;
+
+        sdhci_bcm_kona_sd_init(host);
+
+        ret = sdhci_add_host(host);
+        if (ret) {
+                dev_err(dev, "Failed sdhci_add_host\n");
+                goto err_reset;
+        }
+
+        /* if device is eMMC, emulate card insert right here */
+        if (host->mmc->caps | MMC_CAP_NONREMOVABLE) {
+                ret = sdhci_bcm_kona_sd_card_emulate(host, 1);
+                if (ret) {
+                        dev_err(dev,
+                                "unable to emulate card insertion\n");
+                        goto err_remove_host;
+                }
+        }
+        /*
+         * Since the card detection GPIO interrupt is configured to be
+         * edge sensitive, check the initial GPIO value here, emulate
+         * only if the card is present
+         */
+        if (mmc_gpio_get_cd(host->mmc) > 0)
+                sdhci_bcm_kona_sd_card_emulate(host, 1);
+
+        dev_dbg(dev, "initialized properly\n");
+        return 0;
+
+err_remove_host:
+        sdhci_remove_host(host, 0);
+
+err_reset:
+        sdhci_bcm_kona_sd_reset(host);
+
+err_pltfm_free:
+        sdhci_pltfm_free(pdev);
+
+        dev_err(dev, "Probing of sdhci-pltfm failed: %d\n", ret);
+        return ret;
+}
+
+static int __exit sdhci_bcm_kona_remove(struct platform_device *pdev)
+{
+        struct sdhci_host *host = platform_get_drvdata(pdev);
+        int dead;
+        u32 scratch;
+
+        dead = 0;
+        scratch = readl(host->ioaddr + SDHCI_INT_STATUS);
+        if (scratch == (u32)-1)
+                dead = 1;
+        sdhci_remove_host(host, dead);
+
+        sdhci_free_host(host);
+
+        return 0;
+}
+
+static struct platform_driver sdhci_bcm_kona_driver = {
+        .driver         = {
+                .name   = "sdhci-kona",
+                .owner  = THIS_MODULE,
+                .pm     = SDHCI_PLTFM_PMOPS,
+                .of_match_table = of_match_ptr(sdhci_bcm_kona_of_match),
+        },
+        .probe          = sdhci_bcm_kona_probe,
+        .remove         = __exit_p(sdhci_bcm_kona_remove),
+};
+module_platform_driver(sdhci_bcm_kona_driver);
+
+MODULE_DESCRIPTION("SDHCI driver for Broadcom Kona platform");
+MODULE_AUTHOR("Broadcom");
+MODULE_LICENSE("GPL v2");