mmc: USB SD Host Controller (USHC) driver

Add a driver for USB SD Host Controller devices.  These devices are
Cypress Astoria chips with firmware compliant with issue 2 of CSR's USHC
specification.

[cjb: adapt to block layer deprecation of max_{hw,phys}_segs]
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

3 files changed, 581 insertions, 0 deletions

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 68d12794cfd9..8de7b9e8fc51 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -451,3 +451,17 @@ config MMC_JZ4740
           SoCs.
           If you have a board based on such a SoC and with a SD/MMC slot,
           say Y or M here.
+
+config MMC_USHC
+        tristate "USB SD Host Controller (USHC) support"
+        depends on USB
+        help
+          This selects support for USB SD Host Controllers based on
+          the Cypress Astoria chip with firmware compliant with CSR's
+          USB SD Host Controller specification (CS-118793-SP).
+
+          CSR boards with this device include: USB<>SDIO (M1985v2),
+          and Ultrasira.
+
+          Note: These controllers only support SDIO cards and do not
+          support MMC or SD memory cards.
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 840bcb52d82f..f7fb7eb234b9 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_MMC_VIA_SDMMC)	+= via-sdmmc.o
 obj-$(CONFIG_SDH_BFIN)          += bfin_sdh.o
 obj-$(CONFIG_MMC_SH_MMCIF)      += sh_mmcif.o
 obj-$(CONFIG_MMC_JZ4740)        += jz4740_mmc.o
+obj-$(CONFIG_MMC_USHC)          += ushc.o
 
 obj-$(CONFIG_MMC_SDHCI_PLTFM)                   += sdhci-platform.o
 sdhci-platform-y                                := sdhci-pltfm.o
diff --git a/drivers/mmc/host/ushc.c b/drivers/mmc/host/ushc.c
new file mode 100644
index 000000000000..b4ead4a13c98
--- /dev/null
+++ b/drivers/mmc/host/ushc.c
@@ -0,0 +1,566 @@
+/*
+ * USB SD Host Controller (USHC) controller driver.
+ *
+ * Copyright (C) 2010 Cambridge Silicon Radio Ltd.
+ *
+ * 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.
+ *
+ * Notes:
+ *   - Only version 2 devices are supported.
+ *   - Version 2 devices only support SDIO cards/devices (R2 response is
+ *     unsupported).
+ *
+ * References:
+ *   [USHC] USB SD Host Controller specification (CS-118793-SP)
+ */
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/kernel.h>
+#include <linux/usb.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+#include <linux/mmc/host.h>
+
+enum ushc_request {
+        USHC_GET_CAPS  = 0x00,
+        USHC_HOST_CTRL = 0x01,
+        USHC_PWR_CTRL  = 0x02,
+        USHC_CLK_FREQ  = 0x03,
+        USHC_EXEC_CMD  = 0x04,
+        USHC_READ_RESP = 0x05,
+        USHC_RESET     = 0x06,
+};
+
+enum ushc_request_type {
+        USHC_GET_CAPS_TYPE  = USB_DIR_IN  | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+        USHC_HOST_CTRL_TYPE = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+        USHC_PWR_CTRL_TYPE  = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+        USHC_CLK_FREQ_TYPE  = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+        USHC_EXEC_CMD_TYPE  = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+        USHC_READ_RESP_TYPE = USB_DIR_IN  | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+        USHC_RESET_TYPE     = USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+};
+
+#define USHC_GET_CAPS_VERSION_MASK 0xff
+#define USHC_GET_CAPS_3V3      (1 << 8)
+#define USHC_GET_CAPS_3V0      (1 << 9)
+#define USHC_GET_CAPS_1V8      (1 << 10)
+#define USHC_GET_CAPS_HIGH_SPD (1 << 16)
+
+#define USHC_HOST_CTRL_4BIT     (1 << 1)
+#define USHC_HOST_CTRL_HIGH_SPD (1 << 0)
+
+#define USHC_PWR_CTRL_OFF 0x00
+#define USHC_PWR_CTRL_3V3 0x01
+#define USHC_PWR_CTRL_3V0 0x02
+#define USHC_PWR_CTRL_1V8 0x03
+
+#define USHC_READ_RESP_BUSY        (1 << 4)
+#define USHC_READ_RESP_ERR_TIMEOUT (1 << 3)
+#define USHC_READ_RESP_ERR_CRC     (1 << 2)
+#define USHC_READ_RESP_ERR_DAT     (1 << 1)
+#define USHC_READ_RESP_ERR_CMD     (1 << 0)
+#define USHC_READ_RESP_ERR_MASK    0x0f
+
+struct ushc_cbw {
+        __u8 signature;
+        __u8 cmd_idx;
+        __le16 block_size;
+        __le32 arg;
+} __attribute__((packed));
+
+#define USHC_CBW_SIGNATURE 'C'
+
+struct ushc_csw {
+        __u8 signature;
+        __u8 status;
+        __le32 response;
+} __attribute__((packed));
+
+#define USHC_CSW_SIGNATURE 'S'
+
+struct ushc_int_data {
+        u8 status;
+        u8 reserved[3];
+};
+
+#define USHC_INT_STATUS_SDIO_INT     (1 << 1)
+#define USHC_INT_STATUS_CARD_PRESENT (1 << 0)
+
+
+struct ushc_data {
+        struct usb_device *usb_dev;
+        struct mmc_host *mmc;
+
+        struct urb *int_urb;
+        struct ushc_int_data *int_data;
+
+        struct urb *cbw_urb;
+        struct ushc_cbw *cbw;
+
+        struct urb *data_urb;
+
+        struct urb *csw_urb;
+        struct ushc_csw *csw;
+
+        spinlock_t lock;
+        struct mmc_request *current_req;
+        u32 caps;
+        u16 host_ctrl;
+        unsigned long flags;
+        u8 last_status;
+        int clock_freq;
+};
+
+#define DISCONNECTED    0
+#define INT_EN          1
+#define IGNORE_NEXT_INT 2
+
+static void data_callback(struct urb *urb);
+
+static int ushc_hw_reset(struct ushc_data *ushc)
+{
+        return usb_control_msg(ushc->usb_dev, usb_sndctrlpipe(ushc->usb_dev, 0),
+                               USHC_RESET, USHC_RESET_TYPE,
+                               0, 0, NULL, 0, 100);
+}
+
+static int ushc_hw_get_caps(struct ushc_data *ushc)
+{
+        int ret;
+        int version;
+
+        ret = usb_control_msg(ushc->usb_dev, usb_rcvctrlpipe(ushc->usb_dev, 0),
+                              USHC_GET_CAPS, USHC_GET_CAPS_TYPE,
+                              0, 0, &ushc->caps, sizeof(ushc->caps), 100);
+        if (ret < 0)
+                return ret;
+
+        ushc->caps = le32_to_cpu(ushc->caps);
+
+        version = ushc->caps & USHC_GET_CAPS_VERSION_MASK;
+        if (version != 0x02) {
+                dev_err(&ushc->usb_dev->dev, "controller version %d is not supported\n", version);
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static int ushc_hw_set_host_ctrl(struct ushc_data *ushc, u16 mask, u16 val)
+{
+        u16 host_ctrl;
+        int ret;
+
+        host_ctrl = (ushc->host_ctrl & ~mask) | val;
+        ret = usb_control_msg(ushc->usb_dev, usb_sndctrlpipe(ushc->usb_dev, 0),
+                              USHC_HOST_CTRL, USHC_HOST_CTRL_TYPE,
+                              host_ctrl, 0, NULL, 0, 100);
+        if (ret < 0)
+                return ret;
+        ushc->host_ctrl = host_ctrl;
+        return 0;
+}
+
+static void int_callback(struct urb *urb)
+{
+        struct ushc_data *ushc = urb->context;
+        u8 status, last_status;
+
+        if (urb->status < 0)
+                return;
+
+        status = ushc->int_data->status;
+        last_status = ushc->last_status;
+        ushc->last_status = status;
+
+        /*
+         * Ignore the card interrupt status on interrupt transfers that
+         * were submitted while card interrupts where disabled.
+         *
+         * This avoid occasional spurious interrupts when enabling
+         * interrupts immediately after clearing the source on the card.
+         */
+
+        if (!test_and_clear_bit(IGNORE_NEXT_INT, &ushc->flags)
+            && test_bit(INT_EN, &ushc->flags)
+            && status & USHC_INT_STATUS_SDIO_INT) {
+                mmc_signal_sdio_irq(ushc->mmc);
+        }
+
+        if ((status ^ last_status) & USHC_INT_STATUS_CARD_PRESENT)
+                mmc_detect_change(ushc->mmc, msecs_to_jiffies(100));
+
+        if (!test_bit(INT_EN, &ushc->flags))
+                set_bit(IGNORE_NEXT_INT, &ushc->flags);
+        usb_submit_urb(ushc->int_urb, GFP_ATOMIC);
+}
+
+static void cbw_callback(struct urb *urb)
+{
+        struct ushc_data *ushc = urb->context;
+
+        if (urb->status != 0) {
+                usb_unlink_urb(ushc->data_urb);
+                usb_unlink_urb(ushc->csw_urb);
+        }
+}
+
+static void data_callback(struct urb *urb)
+{
+        struct ushc_data *ushc = urb->context;
+
+        if (urb->status != 0)
+                usb_unlink_urb(ushc->csw_urb);
+}
+
+static void csw_callback(struct urb *urb)
+{
+        struct ushc_data *ushc = urb->context;
+        struct mmc_request *req = ushc->current_req;
+        int status;
+
+        status = ushc->csw->status;
+
+        if (urb->status != 0) {
+                req->cmd->error = urb->status;
+        } else if (status & USHC_READ_RESP_ERR_CMD) {
+                if (status & USHC_READ_RESP_ERR_CRC)
+                        req->cmd->error = -EIO;
+                else
+                        req->cmd->error = -ETIMEDOUT;
+        }
+        if (req->data) {
+                if (status & USHC_READ_RESP_ERR_DAT) {
+                        if (status & USHC_READ_RESP_ERR_CRC)
+                                req->data->error = -EIO;
+                        else
+                                req->data->error = -ETIMEDOUT;
+                        req->data->bytes_xfered = 0;
+                } else {
+                        req->data->bytes_xfered = req->data->blksz * req->data->blocks;
+                }
+        }
+
+        req->cmd->resp[0] = le32_to_cpu(ushc->csw->response);
+
+        mmc_request_done(ushc->mmc, req);
+}
+
+static void ushc_request(struct mmc_host *mmc, struct mmc_request *req)
+{
+        struct ushc_data *ushc = mmc_priv(mmc);
+        int ret;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ushc->lock, flags);
+
+        if (test_bit(DISCONNECTED, &ushc->flags)) {
+                ret = -ENODEV;
+                goto out;
+        }
+
+        /* Version 2 firmware doesn't support the R2 response format. */
+        if (req->cmd->flags & MMC_RSP_136) {
+                ret = -EINVAL;
+                goto out;
+        }
+
+        /* The Astoria's data FIFOs don't work with clock speeds < 5MHz so
+           limit commands with data to 6MHz or more. */
+        if (req->data && ushc->clock_freq < 6000000) {
+                ret = -EINVAL;
+                goto out;
+        }
+
+        ushc->current_req = req;
+
+        /* Start cmd with CBW. */
+        ushc->cbw->cmd_idx = cpu_to_le16(req->cmd->opcode);
+        if (req->data)
+                ushc->cbw->block_size = cpu_to_le16(req->data->blksz);
+        else
+                ushc->cbw->block_size = 0;
+        ushc->cbw->arg = cpu_to_le32(req->cmd->arg);
+
+        ret = usb_submit_urb(ushc->cbw_urb, GFP_ATOMIC);
+        if (ret < 0)
+                goto out;
+
+        /* Submit data (if any). */
+        if (req->data) {
+                struct mmc_data *data = req->data;
+                int pipe;
+
+                if (data->flags & MMC_DATA_READ)
+                        pipe = usb_rcvbulkpipe(ushc->usb_dev, 6);
+                else
+                        pipe = usb_sndbulkpipe(ushc->usb_dev, 2);
+
+                usb_fill_bulk_urb(ushc->data_urb, ushc->usb_dev, pipe,
+                                  sg_virt(data->sg), data->sg->length,
+                                  data_callback, ushc);
+                ret = usb_submit_urb(ushc->data_urb, GFP_ATOMIC);
+                if (ret < 0)
+                        goto out;
+        }
+
+        /* Submit CSW. */
+        ret = usb_submit_urb(ushc->csw_urb, GFP_ATOMIC);
+        if (ret < 0)
+                goto out;
+
+out:
+        spin_unlock_irqrestore(&ushc->lock, flags);
+        if (ret < 0) {
+                usb_unlink_urb(ushc->cbw_urb);
+                usb_unlink_urb(ushc->data_urb);
+                req->cmd->error = ret;
+                mmc_request_done(mmc, req);
+        }
+}
+
+static int ushc_set_power(struct ushc_data *ushc, unsigned char power_mode)
+{
+        u16 voltage;
+
+        switch (power_mode) {
+        case MMC_POWER_OFF:
+                voltage = USHC_PWR_CTRL_OFF;
+                break;
+        case MMC_POWER_UP:
+        case MMC_POWER_ON:
+                voltage = USHC_PWR_CTRL_3V3;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return usb_control_msg(ushc->usb_dev, usb_sndctrlpipe(ushc->usb_dev, 0),
+                               USHC_PWR_CTRL, USHC_PWR_CTRL_TYPE,
+                               voltage, 0, NULL, 0, 100);
+}
+
+static int ushc_set_bus_width(struct ushc_data *ushc, int bus_width)
+{
+        return ushc_hw_set_host_ctrl(ushc, USHC_HOST_CTRL_4BIT,
+                                     bus_width == 4 ? USHC_HOST_CTRL_4BIT : 0);
+}
+
+static int ushc_set_bus_freq(struct ushc_data *ushc, int clk, bool enable_hs)
+{
+        int ret;
+
+        /* Hardware can't detect interrupts while the clock is off. */
+        if (clk == 0)
+                clk = 400000;
+
+        ret = ushc_hw_set_host_ctrl(ushc, USHC_HOST_CTRL_HIGH_SPD,
+                                    enable_hs ? USHC_HOST_CTRL_HIGH_SPD : 0);
+        if (ret < 0)
+                return ret;
+
+        ret = usb_control_msg(ushc->usb_dev, usb_sndctrlpipe(ushc->usb_dev, 0),
+                              USHC_CLK_FREQ, USHC_CLK_FREQ_TYPE,
+                              clk & 0xffff, (clk >> 16) & 0xffff, NULL, 0, 100);
+        if (ret < 0)
+                return ret;
+
+        ushc->clock_freq = clk;
+        return 0;
+}
+
+static void ushc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+        struct ushc_data *ushc = mmc_priv(mmc);
+
+        ushc_set_power(ushc, ios->power_mode);
+        ushc_set_bus_width(ushc, 1 << ios->bus_width);
+        ushc_set_bus_freq(ushc, ios->clock, ios->timing == MMC_TIMING_SD_HS);
+}
+
+static int ushc_get_cd(struct mmc_host *mmc)
+{
+        struct ushc_data *ushc = mmc_priv(mmc);
+
+        return !!(ushc->last_status & USHC_INT_STATUS_CARD_PRESENT);
+}
+
+static void ushc_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+        struct ushc_data *ushc = mmc_priv(mmc);
+
+        if (enable)
+                set_bit(INT_EN, &ushc->flags);
+        else
+                clear_bit(INT_EN, &ushc->flags);
+}
+
+static void ushc_clean_up(struct ushc_data *ushc)
+{
+        usb_free_urb(ushc->int_urb);
+        usb_free_urb(ushc->csw_urb);
+        usb_free_urb(ushc->data_urb);
+        usb_free_urb(ushc->cbw_urb);
+
+        kfree(ushc->int_data);
+        kfree(ushc->cbw);
+        kfree(ushc->csw);
+
+        mmc_free_host(ushc->mmc);
+}
+
+static const struct mmc_host_ops ushc_ops = {
+        .request         = ushc_request,
+        .set_ios         = ushc_set_ios,
+        .get_cd          = ushc_get_cd,
+        .enable_sdio_irq = ushc_enable_sdio_irq,
+};
+
+static int ushc_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+        struct usb_device *usb_dev = interface_to_usbdev(intf);
+        struct mmc_host *mmc;
+        struct ushc_data *ushc;
+        int ret = -ENOMEM;
+
+        mmc = mmc_alloc_host(sizeof(struct ushc_data), &intf->dev);
+        if (mmc == NULL)
+                return -ENOMEM;
+        ushc = mmc_priv(mmc);
+        usb_set_intfdata(intf, ushc);
+
+        ushc->usb_dev = usb_dev;
+        ushc->mmc = mmc;
+
+        spin_lock_init(&ushc->lock);
+
+        ret = ushc_hw_reset(ushc);
+        if (ret < 0)
+                goto err;
+
+        /* Read capabilities. */
+        ret = ushc_hw_get_caps(ushc);
+        if (ret < 0)
+                goto err;
+
+        mmc->ops = &ushc_ops;
+
+        mmc->f_min = 400000;
+        mmc->f_max = 50000000;
+        mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
+        mmc->caps = MMC_CAP_4_BIT_DATA | MMC_CAP_SDIO_IRQ;
+        mmc->caps |= (ushc->caps & USHC_GET_CAPS_HIGH_SPD) ? MMC_CAP_SD_HIGHSPEED : 0;
+
+        mmc->max_seg_size  = 512*511;
+        mmc->max_segs      = 1;
+        mmc->max_req_size  = 512*511;
+        mmc->max_blk_size  = 512;
+        mmc->max_blk_count = 511;
+
+        ushc->int_urb = usb_alloc_urb(0, GFP_KERNEL);
+        if (ushc->int_urb == NULL)
+                goto err;
+        ushc->int_data = kzalloc(sizeof(struct ushc_int_data), GFP_KERNEL);
+        if (ushc->int_data == NULL)
+                goto err;
+        usb_fill_int_urb(ushc->int_urb, ushc->usb_dev,
+                         usb_rcvintpipe(usb_dev,
+                                        intf->cur_altsetting->endpoint[0].desc.bEndpointAddress),
+                         ushc->int_data, sizeof(struct ushc_int_data),
+                         int_callback, ushc,
+                         intf->cur_altsetting->endpoint[0].desc.bInterval);
+
+        ushc->cbw_urb = usb_alloc_urb(0, GFP_KERNEL);
+        if (ushc->cbw_urb == NULL)
+                goto err;
+        ushc->cbw = kzalloc(sizeof(struct ushc_cbw), GFP_KERNEL);
+        if (ushc->cbw == NULL)
+                goto err;
+        ushc->cbw->signature = USHC_CBW_SIGNATURE;
+
+        usb_fill_bulk_urb(ushc->cbw_urb, ushc->usb_dev, usb_sndbulkpipe(usb_dev, 2),
+                          ushc->cbw, sizeof(struct ushc_cbw),
+                          cbw_callback, ushc);
+
+        ushc->data_urb = usb_alloc_urb(0, GFP_KERNEL);
+        if (ushc->data_urb == NULL)
+                goto err;
+
+        ushc->csw_urb = usb_alloc_urb(0, GFP_KERNEL);
+        if (ushc->csw_urb == NULL)
+                goto err;
+        ushc->csw = kzalloc(sizeof(struct ushc_cbw), GFP_KERNEL);
+        if (ushc->csw == NULL)
+                goto err;
+        usb_fill_bulk_urb(ushc->csw_urb, ushc->usb_dev, usb_rcvbulkpipe(usb_dev, 6),
+                          ushc->csw, sizeof(struct ushc_csw),
+                          csw_callback, ushc);
+
+        ret = mmc_add_host(ushc->mmc);
+        if (ret)
+                goto err;
+
+        ret = usb_submit_urb(ushc->int_urb, GFP_KERNEL);
+        if (ret < 0) {
+                mmc_remove_host(ushc->mmc);
+                goto err;
+        }
+
+        return 0;
+
+err:
+        ushc_clean_up(ushc);
+        return ret;
+}
+
+static void ushc_disconnect(struct usb_interface *intf)
+{
+        struct ushc_data *ushc = usb_get_intfdata(intf);
+
+        spin_lock_irq(&ushc->lock);
+        set_bit(DISCONNECTED, &ushc->flags);
+        spin_unlock_irq(&ushc->lock);
+
+        usb_kill_urb(ushc->int_urb);
+        usb_kill_urb(ushc->cbw_urb);
+        usb_kill_urb(ushc->data_urb);
+        usb_kill_urb(ushc->csw_urb);
+
+        mmc_remove_host(ushc->mmc);
+
+        ushc_clean_up(ushc);
+}
+
+static struct usb_device_id ushc_id_table[] = {
+        /* CSR USB SD Host Controller */
+        { USB_DEVICE(0x0a12, 0x5d10) },
+        { },
+};
+MODULE_DEVICE_TABLE(usb, ushc_id_table);
+
+static struct usb_driver ushc_driver = {
+        .name       = "ushc",
+        .id_table   = ushc_id_table,
+        .probe      = ushc_probe,
+        .disconnect = ushc_disconnect,
+};
+
+static int __init ushc_init(void)
+{
+        return usb_register(&ushc_driver);
+}
+module_init(ushc_init);
+
+static void __exit ushc_exit(void)
+{
+        usb_deregister(&ushc_driver);
+}
+module_exit(ushc_exit);
+
+MODULE_DESCRIPTION("USB SD Host Controller driver");
+MODULE_AUTHOR("David Vrabel <david.vrabel@csr.com>");
+MODULE_LICENSE("GPL");