[PATCH 06/10] goldfish: emulated MMC device

[Alan Cox <alan@linux.intel.com>]

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From: Mike Lockwood <lockwood@android.com>

This driver handles the virtual MMC device present in the Goldfish emulator.
The patch folds together initial work from Mike Lockwood and patches by
San Mehat, Jun Nakajima and Tom Keel <thomas.keel@intel.com> plus cleanups
by Alan Cox to get it all into 3.6 shape.

Signed-off-by: Mike A. Chan <mikechan@google.com>
[cleaned up and x86 support added]
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Xiaohui Xin <xiaohui.xin@intel.com>
Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
[Moved to 3.4]
Signed-off-by: Tom Keel <thomas.keel@intel.com>
[Moved to 3.7]
Signed-off-by: Alan Cox <alan@linux.intel.com>
---

 drivers/mmc/host/Kconfig    |    7 +
 drivers/mmc/host/Makefile   |    1 
 drivers/mmc/host/goldfish.c |  577 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 585 insertions(+)
 create mode 100644 drivers/mmc/host/goldfish.c


diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index cc8a8fa..f5d308d 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -361,6 +361,13 @@ config MMC_DAVINCI
           If you have an DAVINCI board with a Multimedia Card slot,
           say Y or M here.  If unsure, say N.
 
+config MMC_GOLDFISH
+	tristate "goldfish qemu Multimedia Card Interface support"
+	depends on GOLDFISH
+	help
+	  This selects the Goldfish Multimedia card Interface emulation
+	  found on the Goldfish Android virtual device emulation.
+
 config MMC_SPI
 	tristate "MMC/SD/SDIO over SPI"
 	depends on SPI_MASTER && !HIGHMEM && HAS_DMA
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index e4e218c..2ad0e16 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_MMC_TIFM_SD)	+= tifm_sd.o
 obj-$(CONFIG_MMC_MSM)		+= msm_sdcc.o
 obj-$(CONFIG_MMC_MVSDIO)	+= mvsdio.o
 obj-$(CONFIG_MMC_DAVINCI)       += davinci_mmc.o
+obj-$(CONFIG_MMC_GOLDFISH)	+= goldfish.o
 obj-$(CONFIG_MMC_SPI)		+= mmc_spi.o
 ifeq ($(CONFIG_OF),y)
 obj-$(CONFIG_MMC_SPI)		+= of_mmc_spi.o
diff --git a/drivers/mmc/host/goldfish.c b/drivers/mmc/host/goldfish.c
new file mode 100644
index 0000000..1d01ace
--- /dev/null
+++ b/drivers/mmc/host/goldfish.c
@@ -0,0 +1,577 @@
+/*
+ *  Copyright 2007, Google Inc.
+ *  Copyright 2012, Intel Inc.
+ *
+ *  based on omap.c driver, which was
+ *  Copyright (C) 2004 Nokia Corporation
+ *  Written by Tuukka Tikkanen and Juha Yrjölä<juha.yrjola@nokia.com>
+ *  Misc hacks here and there by Tony Lindgren <tony@atomide.com>
+ *  Other hacks (DMA, SD, etc) by David Brownell
+ *
+ * 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/module.h>
+#include <linux/platform_device.h>
+#include <linux/major.h>
+
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/hdreg.h>
+#include <linux/kdev_t.h>
+#include <linux/blkdev.h>
+#include <linux/mutex.h>
+#include <linux/scatterlist.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/sdio.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/card.h>
+
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/dma-mapping.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <linux/clk.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/scatterlist.h>
+
+#include <asm/types.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#define DRIVER_NAME "goldfish_mmc"
+
+#define BUFFER_SIZE   16384
+
+#define GOLDFISH_MMC_READ(host, addr)   (readl(host->reg_base + addr))
+#define GOLDFISH_MMC_WRITE(host, addr, x)   (writel(x, host->reg_base + addr))
+
+
+enum {
+	/* status register */
+	MMC_INT_STATUS	        = 0x00,
+	/* set this to enable IRQ */
+	MMC_INT_ENABLE	        = 0x04,
+	/* set this to specify buffer address */
+	MMC_SET_BUFFER          = 0x08,
+
+	/* MMC command number */
+	MMC_CMD	                = 0x0C,
+
+	/* MMC argument */
+	MMC_ARG	                = 0x10,
+
+	/* MMC response (or R2 bits 0 - 31) */
+	MMC_RESP_0		        = 0x14,
+
+	/* MMC R2 response bits 32 - 63 */
+	MMC_RESP_1		        = 0x18,
+
+	/* MMC R2 response bits 64 - 95 */
+	MMC_RESP_2		        = 0x1C,
+
+	/* MMC R2 response bits 96 - 127 */
+	MMC_RESP_3		        = 0x20,
+
+	MMC_BLOCK_LENGTH        = 0x24,
+	MMC_BLOCK_COUNT         = 0x28,
+
+	/* MMC state flags */
+	MMC_STATE               = 0x2C,
+
+	/* MMC_INT_STATUS bits */
+
+	MMC_STAT_END_OF_CMD     = 1U << 0,
+	MMC_STAT_END_OF_DATA    = 1U << 1,
+	MMC_STAT_STATE_CHANGE   = 1U << 2,
+	MMC_STAT_CMD_TIMEOUT    = 1U << 3,
+
+	/* MMC_STATE bits */
+	MMC_STATE_INSERTED     = 1U << 0,
+	MMC_STATE_READ_ONLY    = 1U << 1,
+};
+
+/*
+ * Command types
+ */
+#define OMAP_MMC_CMDTYPE_BC	0
+#define OMAP_MMC_CMDTYPE_BCR	1
+#define OMAP_MMC_CMDTYPE_AC	2
+#define OMAP_MMC_CMDTYPE_ADTC	3
+
+
+struct goldfish_mmc_host {
+	struct mmc_request	*mrq;
+	struct mmc_command	*cmd;
+	struct mmc_data		*data;
+	struct mmc_host		*mmc;
+	struct device		*dev;
+	unsigned char		id; /* 16xx chips have 2 MMC blocks */
+	void __iomem		*virt_base;
+	unsigned int		phys_base;
+	int			irq;
+	unsigned char		bus_mode;
+	unsigned char		hw_bus_mode;
+
+	unsigned int		sg_len;
+	unsigned		dma_done:1;
+	unsigned		dma_in_use:1;
+
+	void __iomem		*reg_base;
+};
+
+static inline int
+goldfish_mmc_cover_is_open(struct goldfish_mmc_host *host)
+{
+	return 0;
+}
+
+static ssize_t
+goldfish_mmc_show_cover_switch(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct goldfish_mmc_host *host = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%s\n", goldfish_mmc_cover_is_open(host) ? "open" :
+			"closed");
+}
+
+static DEVICE_ATTR(cover_switch, S_IRUGO, goldfish_mmc_show_cover_switch, NULL);
+
+static void
+goldfish_mmc_start_command(struct goldfish_mmc_host *host, struct mmc_command *cmd)
+{
+	u32 cmdreg;
+	u32 resptype;
+	u32 cmdtype;
+
+	host->cmd = cmd;
+
+	resptype = 0;
+	cmdtype = 0;
+
+	/* Our hardware needs to know exact type */
+	switch (mmc_resp_type(cmd)) {
+	case MMC_RSP_NONE:
+		break;
+	case MMC_RSP_R1:
+	case MMC_RSP_R1B:
+		/* resp 1, 1b, 6, 7 */
+		resptype = 1;
+		break;
+	case MMC_RSP_R2:
+		resptype = 2;
+		break;
+	case MMC_RSP_R3:
+		resptype = 3;
+		break;
+	default:
+		dev_err(mmc_dev(host->mmc),
+			"Invalid response type: %04x\n", mmc_resp_type(cmd));
+		break;
+	}
+
+	if (mmc_cmd_type(cmd) == MMC_CMD_ADTC)
+		cmdtype = OMAP_MMC_CMDTYPE_ADTC;
+	else if (mmc_cmd_type(cmd) == MMC_CMD_BC)
+		cmdtype = OMAP_MMC_CMDTYPE_BC;
+	else if (mmc_cmd_type(cmd) == MMC_CMD_BCR)
+		cmdtype = OMAP_MMC_CMDTYPE_BCR;
+	else
+		cmdtype = OMAP_MMC_CMDTYPE_AC;
+
+	cmdreg = cmd->opcode | (resptype << 8) | (cmdtype << 12);
+
+	if (host->bus_mode == MMC_BUSMODE_OPENDRAIN)
+		cmdreg |= 1 << 6;
+
+	if (cmd->flags & MMC_RSP_BUSY)
+		cmdreg |= 1 << 11;
+
+	if (host->data && !(host->data->flags & MMC_DATA_WRITE))
+		cmdreg |= 1 << 15;
+
+	GOLDFISH_MMC_WRITE(host, MMC_ARG, cmd->arg);
+	GOLDFISH_MMC_WRITE(host, MMC_CMD, cmdreg);
+}
+
+static void goldfish_mmc_xfer_done(struct goldfish_mmc_host *host,
+							struct mmc_data *data)
+{
+	if (host->dma_in_use) {
+		enum dma_data_direction dma_data_dir;
+
+		if (data->flags & MMC_DATA_WRITE)
+			dma_data_dir = DMA_TO_DEVICE;
+		else
+			dma_data_dir = DMA_FROM_DEVICE;
+
+		if (dma_data_dir == DMA_FROM_DEVICE) {
+			/*
+			 * We don't really have DMA, so we need
+			 * to copy from our platform driver buffer
+			 */
+			uint8_t *dest = (uint8_t *)sg_virt(data->sg);
+			memcpy(dest, host->virt_base, data->sg->length);
+		}
+		host->data->bytes_xfered += data->sg->length;
+		dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->sg_len,
+								dma_data_dir);
+	}
+
+	host->data = NULL;
+	host->sg_len = 0;
+
+	/* NOTE:  MMC layer will sometimes poll-wait CMD13 next, issuing
+	 * dozens of requests until the card finishes writing data.
+	 * It'd be cheaper to just wait till an EOFB interrupt arrives...
+	 */
+
+	if (!data->stop) {
+		host->mrq = NULL;
+		mmc_request_done(host->mmc, data->mrq);
+		return;
+	}
+
+	goldfish_mmc_start_command(host, data->stop);
+}
+
+static void goldfish_mmc_end_of_data(struct goldfish_mmc_host *host,
+							struct mmc_data *data)
+{
+	if (!host->dma_in_use) {
+		goldfish_mmc_xfer_done(host, data);
+		return;
+	}
+	if (host->dma_done)
+		goldfish_mmc_xfer_done(host, data);
+}
+
+static void goldfish_mmc_cmd_done(struct goldfish_mmc_host *host,
+						struct mmc_command *cmd)
+{
+	host->cmd = NULL;
+	if (cmd->flags & MMC_RSP_PRESENT) {
+		if (cmd->flags & MMC_RSP_136) {
+			/* response type 2 */
+			cmd->resp[3] =
+				GOLDFISH_MMC_READ(host, MMC_RESP_0);
+			cmd->resp[2] =
+				GOLDFISH_MMC_READ(host, MMC_RESP_1);
+			cmd->resp[1] =
+				GOLDFISH_MMC_READ(host, MMC_RESP_2);
+			cmd->resp[0] =
+				GOLDFISH_MMC_READ(host, MMC_RESP_3);
+		} else {
+			/* response types 1, 1b, 3, 4, 5, 6 */
+			cmd->resp[0] =
+				GOLDFISH_MMC_READ(host, MMC_RESP_0);
+		}
+	}
+
+	if (host->data == NULL || cmd->error) {
+		host->mrq = NULL;
+		mmc_request_done(host->mmc, cmd->mrq);
+	}
+}
+
+static irqreturn_t goldfish_mmc_irq(int irq, void *dev_id)
+{
+	struct goldfish_mmc_host *host = (struct goldfish_mmc_host *)dev_id;
+	u16 status;
+	int end_command = 0;
+	int end_transfer = 0;
+	int transfer_error = 0;
+	int state_changed = 0;
+	int cmd_timeout = 0;
+
+	while ((status = GOLDFISH_MMC_READ(host, MMC_INT_STATUS)) != 0) {
+		GOLDFISH_MMC_WRITE(host, MMC_INT_STATUS, status);
+
+		if (status & MMC_STAT_END_OF_CMD)
+			end_command = 1;
+
+		if (status & MMC_STAT_END_OF_DATA)
+			end_transfer = 1;
+
+		if (status & MMC_STAT_STATE_CHANGE)
+			state_changed = 1;
+
+                if (status & MMC_STAT_CMD_TIMEOUT) {
+			end_command = 0;
+			cmd_timeout = 1;
+                }
+	}
+
+	if (cmd_timeout) {
+		struct mmc_request *mrq = host->mrq;
+		mrq->cmd->error = -ETIMEDOUT;
+		host->mrq = NULL;
+		mmc_request_done(host->mmc, mrq);
+	}
+
+	if (end_command)
+		goldfish_mmc_cmd_done(host, host->cmd);
+
+	if (transfer_error)
+		goldfish_mmc_xfer_done(host, host->data);
+	else if (end_transfer) {
+		host->dma_done = 1;
+		goldfish_mmc_end_of_data(host, host->data);
+	} else if (host->data != NULL) {
+		/*
+		 * WORKAROUND -- after porting this driver from 2.6 to 3.4,
+		 * during device initialization, cases where host->data is
+		 * non-null but end_transfer is false would occur. Doing
+		 * nothing in such cases results in no further interrupts,
+		 * and initialization failure.
+		 * TODO -- find the real cause.
+		 */
+		host->dma_done = 1;
+		goldfish_mmc_end_of_data(host, host->data);
+	}
+
+	if (state_changed) {
+		u32 state = GOLDFISH_MMC_READ(host, MMC_STATE);
+		pr_info("%s: Card detect now %d\n", __func__,
+			(state & MMC_STATE_INSERTED));
+		mmc_detect_change(host->mmc, 0);
+	}
+
+	if (!end_command && !end_transfer &&
+	    !transfer_error && !state_changed && !cmd_timeout) {
+		status = GOLDFISH_MMC_READ(host, MMC_INT_STATUS);
+		dev_info(mmc_dev(host->mmc),"spurious irq 0x%04x\n", status);
+		if (status != 0) {
+			GOLDFISH_MMC_WRITE(host, MMC_INT_STATUS, status);
+			GOLDFISH_MMC_WRITE(host, MMC_INT_ENABLE, 0);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void goldfish_mmc_prepare_data(struct goldfish_mmc_host *host,
+						struct mmc_request *req)
+{
+	struct mmc_data *data = req->data;
+	int block_size;
+	unsigned sg_len;
+	enum dma_data_direction dma_data_dir;
+
+	host->data = data;
+	if (data == NULL) {
+		GOLDFISH_MMC_WRITE(host, MMC_BLOCK_LENGTH, 0);
+		GOLDFISH_MMC_WRITE(host, MMC_BLOCK_COUNT, 0);
+		host->dma_in_use = 0;
+		return;
+	}
+
+	block_size = data->blksz;
+
+	GOLDFISH_MMC_WRITE(host, MMC_BLOCK_COUNT, data->blocks - 1);
+	GOLDFISH_MMC_WRITE(host, MMC_BLOCK_LENGTH, block_size - 1);
+
+	/* cope with calling layer confusion; it issues "single
+	 * block" writes using multi-block scatterlists.
+	 */
+	sg_len = (data->blocks == 1) ? 1 : data->sg_len;
+
+	if (data->flags & MMC_DATA_WRITE)
+		dma_data_dir = DMA_TO_DEVICE;
+	else
+		dma_data_dir = DMA_FROM_DEVICE;
+
+	host->sg_len = dma_map_sg(mmc_dev(host->mmc), data->sg,
+				sg_len, dma_data_dir);
+	host->dma_done = 0;
+	host->dma_in_use = 1;
+
+	if (dma_data_dir == DMA_TO_DEVICE) {
+		/* we don't really have DMA, so we need to copy to our
+		   platform driver buffer */
+		const uint8_t *src = (uint8_t *)sg_virt(data->sg);
+		memcpy(host->virt_base, src, data->sg->length);
+	}
+}
+
+static void goldfish_mmc_request(struct mmc_host *mmc, struct mmc_request *req)
+{
+	struct goldfish_mmc_host *host = mmc_priv(mmc);
+
+	WARN_ON(host->mrq != NULL);
+
+	host->mrq = req;
+	goldfish_mmc_prepare_data(host, req);
+	goldfish_mmc_start_command(host, req->cmd);
+
+	/* this is to avoid accidentally being detected as an SDIO card
+	   in mmc_attach_sdio() */
+	if (req->cmd->opcode == SD_IO_SEND_OP_COND &&
+		req->cmd->flags == (MMC_RSP_SPI_R4 | MMC_RSP_R4 | MMC_CMD_BCR))
+		req->cmd->error = -EINVAL;
+}
+
+static void goldfish_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct goldfish_mmc_host *host = mmc_priv(mmc);
+
+	host->bus_mode = ios->bus_mode;
+	host->hw_bus_mode = host->bus_mode;
+}
+
+static int goldfish_mmc_get_ro(struct mmc_host *mmc)
+{
+	uint32_t state;
+	struct goldfish_mmc_host *host = mmc_priv(mmc);
+
+	state = GOLDFISH_MMC_READ(host, MMC_STATE);
+	return ((state & MMC_STATE_READ_ONLY) != 0);
+}
+
+static const struct mmc_host_ops goldfish_mmc_ops = {
+	.request	= goldfish_mmc_request,
+	.set_ios	= goldfish_mmc_set_ios,
+	.get_ro		= goldfish_mmc_get_ro,
+};
+
+static int __init goldfish_mmc_probe(struct platform_device *pdev)
+{
+	struct mmc_host *mmc;
+	struct goldfish_mmc_host *host = NULL;
+	struct resource *res;
+	int ret = 0;
+	int irq;
+	dma_addr_t buf_addr;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	irq = platform_get_irq(pdev, 0);
+	if (res == NULL || irq < 0)
+		return -ENXIO;
+
+	mmc = mmc_alloc_host(sizeof(struct goldfish_mmc_host), &pdev->dev);
+	if (mmc == NULL) {
+		ret = -ENOMEM;
+		goto err_alloc_host_failed;
+	}
+
+	host = mmc_priv(mmc);
+	host->mmc = mmc;
+
+	pr_err("mmc: Mapping %lX to %lX\n", (long)res->start, (long)res->end);
+	host->reg_base = ioremap(res->start, res->end - res->start + 1);
+	if (host->reg_base == NULL) {
+		ret = -ENOMEM;
+		goto ioremap_failed;
+	}
+	/* FIXME@ discuss with HPA */
+	host->virt_base = dma_alloc_coherent(&pdev->dev, BUFFER_SIZE,
+							&buf_addr, GFP_KERNEL);
+
+	if (host->virt_base == 0) {
+		ret = -ENOMEM;
+		goto dma_alloc_failed;
+	}
+	host->phys_base = buf_addr;
+
+	host->id = pdev->id;
+	host->irq = irq;
+
+	mmc->ops = &goldfish_mmc_ops;
+	mmc->f_min = 400000;
+	mmc->f_max = 24000000;
+	mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
+	mmc->caps = MMC_CAP_4_BIT_DATA;
+
+	/* Use scatterlist DMA to reduce per-transfer costs.
+	 * NOTE max_seg_size assumption that small blocks aren't
+	 * normally used (except e.g. for reading SD registers).
+	 */
+	mmc->max_segs = 32;
+	mmc->max_blk_size = 2048;	/* MMC_BLOCK_LENGTH is 11 bits (+1) */
+	mmc->max_blk_count = 2048;	/* MMC_BLOCK_COUNT is 11 bits (+1) */
+	mmc->max_req_size = BUFFER_SIZE;
+	mmc->max_seg_size = mmc->max_req_size;
+
+	ret = request_irq(host->irq, goldfish_mmc_irq, 0, DRIVER_NAME, host);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed IRQ Adding goldfish MMC\n");
+
+		goto err_request_irq_failed;
+	}
+
+	host->dev = &pdev->dev;
+	platform_set_drvdata(pdev, host);
+
+	ret = device_create_file(&pdev->dev, &dev_attr_cover_switch);
+	if (ret)
+		dev_warn(mmc_dev(host->mmc),
+				"Unable to create sysfs attributes\n");
+
+	GOLDFISH_MMC_WRITE(host, MMC_SET_BUFFER, host->phys_base);
+	GOLDFISH_MMC_WRITE(host, MMC_INT_ENABLE,
+		MMC_STAT_END_OF_CMD | MMC_STAT_END_OF_DATA |
+		MMC_STAT_STATE_CHANGE | MMC_STAT_CMD_TIMEOUT);
+
+	mmc_add_host(mmc);
+	return 0;
+
+err_request_irq_failed:
+	dma_free_coherent(&pdev->dev, BUFFER_SIZE, host->virt_base,
+							host->phys_base);
+dma_alloc_failed:
+	iounmap(host->reg_base);
+ioremap_failed:
+	mmc_free_host(host->mmc);
+err_alloc_host_failed:
+	return ret;
+}
+
+static int goldfish_mmc_remove(struct platform_device *pdev)
+{
+	struct goldfish_mmc_host *host = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	BUG_ON(host == NULL);
+
+	mmc_remove_host(host->mmc);
+	free_irq(host->irq, host);
+	dma_free_coherent(&pdev->dev, BUFFER_SIZE, host->virt_base, host->phys_base);
+	iounmap(host->reg_base);
+	mmc_free_host(host->mmc);
+	return 0;
+}
+
+static struct platform_driver goldfish_mmc_driver = {
+	.probe		= goldfish_mmc_probe,
+	.remove		= goldfish_mmc_remove,
+	.driver		= {
+		.name	= DRIVER_NAME,
+	},
+};
+
+static int __init goldfish_mmc_init(void)
+{
+	return platform_driver_register(&goldfish_mmc_driver);
+}
+
+static void __exit goldfish_mmc_exit(void)
+{
+	platform_driver_unregister(&goldfish_mmc_driver);
+}
+
+module_init(goldfish_mmc_init);
+module_exit(goldfish_mmc_exit);