Re: [PATCH] mflash: remove small byteswapping function

[MinChan Kim]

This is your patch again. 
If you want to review many people, don't send your patch with attach. 
Pz, send your patch with inline. 

You have to use scripts/checkpatch before sending to mainline. 

(linux-arm and linux-embedded Cc:-ed)

> ---
>  drivers/block/Kconfig   |    6 +
>  drivers/block/Makefile  |    2 +
>  drivers/block/mg_disk.c |  878 +++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/mg_disk.h |  174 ++++++++++
>  4 files changed, 1060 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/block/mg_disk.c
>  create mode 100644 include/linux/mg_disk.h
> 
> diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
> index 0344a8a..cad48c8 100644
> --- a/drivers/block/Kconfig
> +++ b/drivers/block/Kconfig
> @@ -403,6 +403,12 @@ config ATA_OVER_ETH
>  	This driver provides Support for ATA over Ethernet block
>  	devices like the Coraid EtherDrive (R) Storage Blade.
>  
> +config MG_DISK
> +	tristate "mGine mflash, gflash support"
> +	depends on ARM
> +	help
> +	  mGine mFlash(gFlash) block device driver
> +
>  config SUNVDC
>  	tristate "Sun Virtual Disk Client support"
>  	depends on SUN_LDOMS
> diff --git a/drivers/block/Makefile b/drivers/block/Makefile
> index 204332b..1694d45 100644
> --- a/drivers/block/Makefile
> +++ b/drivers/block/Makefile
> @@ -32,3 +32,5 @@ obj-$(CONFIG_BLK_DEV_UB)	+= ub.o
>  obj-$(CONFIG_BLK_DEV_HD)	+= hd.o
>  
>  obj-$(CONFIG_XEN_BLKDEV_FRONTEND)	+= xen-blkfront.o
> +
> +obj-$(CONFIG_MG_DISK)	+= mg_disk.o
> diff --git a/drivers/block/mg_disk.c b/drivers/block/mg_disk.c
> new file mode 100644
> index 0000000..6239d01
> --- /dev/null
> +++ b/drivers/block/mg_disk.c
> @@ -0,0 +1,878 @@
> +/*
> + *  drivers/block/mg_disk.c
> + *
> + *  Support for the mGine m[g]flash IO mode.
> + *  Based on legacy hd.c
> + *
> + * (c) 2008 mGine Co.,LTD
> + * (c) 2008 unsik Kim <donari75@xxxxxxxxx>
> + *
> + *  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/kernel.h>
> +#include <linux/module.h>
> +#include <linux/fs.h>
> +#include <linux/blkdev.h>
> +#include <linux/hdreg.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/mg_disk.h>
> +
> +static void mg_request(struct request_queue *);
> +
> +static void mg_dump_status(const char *msg, unsigned int stat, struct mg_host *host)
> +{
> +	char *name = MG_DISK_NAME"?";
> +	struct request *req;
> +
> +	if (host->breq) {
> +		req = elv_next_request(host->breq);
> +		if (req)
> +			name = req->rq_disk->disk_name;
> +	}
> +
> +	printk("%s: %s: status=0x%02x { ", name, msg, stat & 0xff);
> +	if (stat & MG_REG_STATUS_BIT_BUSY)
> +		printk("Busy ");
> +	if (stat & MG_REG_STATUS_BIT_READY)
> +		printk("DriveReady ");
> +	if (stat & MG_REG_STATUS_BIT_WRITE_FAULT)
> +		printk("WriteFault ");
> +	if (stat & MG_REG_STATUS_BIT_SEEK_DONE)
> +		printk("SeekComplete ");
> +	if (stat & MG_REG_STATUS_BIT_DATA_REQ)
> +		printk("DataRequest ");
> +	if (stat & MG_REG_STATUS_BIT_CORRECTED_ERROR)
> +		printk("CorrectedError ");
> +	if (stat & MG_REG_STATUS_BIT_ERROR)
> +		printk("Error ");
> +	printk("}\n");
> +	if ((stat & MG_REG_STATUS_BIT_ERROR) == 0) {
> +		host->error = 0;
> +	} else {
> +		host->error = inb(host->dev_base + MG_REG_ERROR);
> +		printk("%s: %s: error=0x%02x { ", name, msg, host->error & 0xff);
> +		if (host->error & MG_REG_ERR_BBK)
> +			printk("BadSector ");
> +		if (host->error & MG_REG_ERR_UNC)
> +			printk("UncorrectableError ");
> +		if (host->error & MG_REG_ERR_IDNF)
> +			printk("SectorIdNotFound ");
> +		if (host->error & MG_REG_ERR_ABRT)
> +			printk("DriveStatusError ");
> +		if (host->error & MG_REG_ERR_AMNF)
> +			printk("AddrMarkNotFound ");
> +		printk("}");
> +		if (host->error &
> +		    (MG_REG_ERR_BBK | MG_REG_ERR_UNC | MG_REG_ERR_IDNF | MG_REG_ERR_AMNF)) {
> +			if (host->breq) {
> +				req = elv_next_request(host->breq);
> +				if (req)
> +					printk(", sector=%ld", req->sector);
> +			}
> +
> +		}
> +		printk("\n");
> +	}
> +}
> +
> +static unsigned int mg_wait(struct mg_host *host, u32 expect, u32 msec)
> +{
> +	u8 status;
> +	u64 expire, cur_jiffies;
> +
> +	host->error = MG_ERR_NONE;
> +	expire = get_jiffies_64() + msecs_to_jiffies(msec);
> +
> +	status = inb(host->dev_base + MG_REG_STATUS);
> +	do {
> +		cur_jiffies = get_jiffies_64();
> +		if (status & MG_REG_STATUS_BIT_BUSY) {
> +			if (expect == MG_REG_STATUS_BIT_BUSY)
> +				break;
> +		} else {
> +			/* Check the error condition! */
> +			if (status & MG_REG_STATUS_BIT_ERROR) {
> +				mg_dump_status("mg_wait", status, host);
> +				break;
> +			}
> +
> +			if (expect == MG_STAT_READY) {
> +				if (MG_READY_OK(status))
> +					break;
> +			}
> +
> +			if (expect == MG_REG_STATUS_BIT_DATA_REQ) {
> +				if (status & MG_REG_STATUS_BIT_DATA_REQ) {
> +					break;
> +				}
> +			}
> +		}
> +		status = inb(host->dev_base + MG_REG_STATUS);
> +	} while (cur_jiffies < expire);
> +
> +	if (cur_jiffies >= expire) {
> +		host->error = MG_ERR_TIMEOUT;
> +	}
> +
> +	return host->error;
> +}
> +
> +static void mg_unexpected_intr(struct mg_host *host)
> +{
> +	u32 status = inb(host->dev_base + MG_REG_STATUS);
> +
> +	mg_dump_status("mg_unexpected_intr", status, host);
> +}
> +
> +static irqreturn_t mg_irq(int irq, void *dev_id)
> +{
> +	struct mg_host *host = dev_id;
> +	void (*handler)(struct mg_host *) = host->mg_do_intr;
> +
> +	host->mg_do_intr = 0;
> +	del_timer(&host->timer);
> +	if (!handler)
> +		handler = mg_unexpected_intr;
> +	handler(host);
> +	return IRQ_HANDLED;
> +}
> +
> +static void mg_ide_fixstring(u8 *s, const int bytecount)
> +{
> +	u8 *p, *end = &s[bytecount & ~1]; /* bytecount must be even */
> +
> +	/* convert from big-endian to host byte order */
> +	for (p = s ; p != end ; p += 2)
> +		be16_to_cpus((u16 *) p);
> +
> +	/* strip leading blanks */
> +	p = s;
> +	while (s != end && *s == ' ')
> +		++s;
> +	/* compress internal blanks and strip trailing blanks */
> +	while (s != end && *s) {
> +		if (*s++ != ' ' || (s != end && *s && *s != ' '))
> +			*p++ = *(s-1);
> +	}
> +	/* wipe out trailing garbage */
> +	while (p != end)
> +		*p++ = '\0';
> +}
> +
> +static int mg_get_disk_id(struct mg_host *host)
> +{
> +	u32 i;
> +	s32 err;
> +	u16 *id = (u16 *)&host->id_data;
> +	struct mg_drv_data *prv_data = host->dev->platform_data;
> +
> +	if (!prv_data->use_polling) {
> +		outb(MG_REG_CTRL_INTR_DISABLE, host->dev_base + MG_REG_DRV_CTRL);
> +	}
> +
> +	outb(MG_CMD_ID, host->dev_base + MG_REG_COMMAND);
> +	err = mg_wait(host, MG_REG_STATUS_BIT_DATA_REQ, 3000);
> +	if (!err) {
> +		for (i = 0; i < (MG_SECTOR_SIZE >> 1); i++)
> +			id[i] = le16_to_cpu(inw(host->dev_base + MG_BUFF_OFFSET + i * 2));
> +
> +		outb(MG_CMD_RD_CONF, host->dev_base + MG_REG_COMMAND);
> +		err = mg_wait(host, MG_STAT_READY, 3000);
> +		if (!err) {
> +			if ((host->id_data.field_valid & 1) == 0) {
> +				err = MG_ERR_TRANSLATION;
> +			} else {
> +#ifdef __BIG_ENDIAN
> +				host->id_data.lba_capacity = (host->id_data.lba_capacity << 16) | (host->id_data.lba_capacity >> 16);
> +#endif /* __BIG_ENDIAN */
> +				host->tot_sectors = host->id_data.lba_capacity;
> +				mg_ide_fixstring(host->id_data.model, sizeof(host->id_data.model));
> +				mg_ide_fixstring(host->id_data.serial_no, sizeof(host->id_data.serial_no));
> +				mg_ide_fixstring(host->id_data.fw_rev, sizeof(host->id_data.fw_rev));
> +				printk(KERN_INFO "mg_disk: model: %s\n", host->id_data.model);
> +				printk(KERN_INFO "mg_disk: firm: %.8s\n", host->id_data.fw_rev);
> +				printk(KERN_INFO "mg_disk: serial: %s\n", host->id_data.serial_no);
> +				printk(KERN_INFO "mg_disk: %d sectors\n", host->tot_sectors);
> +			}
> +		}
> +	}
> +
> +	if (!prv_data->use_polling) {
> +		outb(MG_REG_CTRL_INTR_ENABLE, host->dev_base + MG_REG_DRV_CTRL);
> +	}
> +
> +	return err;
> +}
> +
> +
> +static int mg_disk_init(struct mg_host *host)
> +{
> +	struct mg_drv_data *prv_data = host->dev->platform_data;
> +	s32 err;
> +	u8 init_status;
> +
> +	/* init ctrl pin */
> +	if (prv_data->mg_ctrl_pin_init)
> +		prv_data->mg_ctrl_pin_init();
> +
> +	if (!prv_data->mg_hdrst_pin)
> +		return MG_ERR_CTRL_RST;
> +
> +	/* hdd rst low */
> +	prv_data->mg_hdrst_pin(0);
> +	err = mg_wait(host, MG_REG_STATUS_BIT_BUSY, 300);
> +	if (err)
> +		return err;
> +
> +	/* hdd rst high */
> +	prv_data->mg_hdrst_pin(1);
> +	err = mg_wait(host, MG_STAT_READY, 3000);
> +	if (err)
> +		return err;
> +
> +	/* soft reset on */
> +	outb(MG_REG_CTRL_RESET |
> +		(prv_data->use_polling ? MG_REG_CTRL_INTR_DISABLE : MG_REG_CTRL_INTR_ENABLE),
> +		host->dev_base + MG_REG_DRV_CTRL);
> +	err = mg_wait(host, MG_REG_STATUS_BIT_BUSY, 3000);
> +	if (err)
> +		return err;
> +
> +	/* soft reset off */
> +	outb(prv_data->use_polling ? MG_REG_CTRL_INTR_DISABLE : MG_REG_CTRL_INTR_ENABLE,
> +		host->dev_base + MG_REG_DRV_CTRL);
> +	err = mg_wait(host, MG_STAT_READY, 3000);
> +	if (err)
> +		return err;
> +
> +	init_status = inb(host->dev_base + MG_REG_STATUS) & 0xf;
> +
> +	if (init_status == 0xf)
> +		return MG_ERR_INIT_STAT;
> +
> +	if (prv_data->op_mode & (MG_OP_CASCADE_SYNC_RD | MG_OP_CASCADE_SYNC_WR)) {
> +		outb(prv_data->burst_latcy | prv_data->burst_len, host->dev_base + MG_REG_BURST_CTRL);
> +	}
> +
> +	return err;
> +}
> +
> +static void mg_bad_rw_intr(struct mg_host *host)
> +{
> +	struct request *req = elv_next_request(host->breq);
> +	if (req != NULL) {
> +		if (++req->errors >= MG_MAX_ERRORS) {
> +			end_request(req, 0);
> +		} else if (req->errors % MG_RESET_FREQ == 0 || host->error == MG_ERR_TIMEOUT) {
> +			host->reset = 1;
> +		}
> +		/* Otherwise just retry */
> +	}
> +}
> +
> +static unsigned int mg_out(struct mg_host *host,
> +			unsigned int sect_num,
> +			unsigned int sect_cnt,
> +			unsigned int cmd,
> +			void (*intr_addr)(struct mg_host *))
> +{
> +	struct mg_drv_data *prv_data = host->dev->platform_data;
> +
> +	if (mg_wait(host, MG_STAT_READY, 3000)) {
> +		return host->error;
> +	}
> +
> +	if (!prv_data->use_polling) {
> +		host->mg_do_intr = intr_addr;
> +		mod_timer(&host->timer, jiffies + 3 * HZ);
> +	}
> +	outb((u8)sect_cnt, host->dev_base + MG_REG_SECT_CNT);
> +	outb((u8)sect_num, host->dev_base + MG_REG_SECT_NUM);
> +	outb((u8)(sect_num >> 8), host->dev_base + MG_REG_CYL_LOW);
> +	outb((u8)(sect_num >> 16), host->dev_base + MG_REG_CYL_HIGH);
> +	outb((u8)((sect_num >> 24) | MG_REG_HEAD_LBA_MODE), host->dev_base + MG_REG_DRV_HEAD);
> +	outb(cmd, host->dev_base + MG_REG_COMMAND);
> +	return MG_ERR_NONE;
> +}
> +
> +static void mg_read(struct request *req)
> +{
> +	u32 remains, j;
> +	struct mg_host *host = req->rq_disk->private_data;
> +
> +	remains = req->nr_sectors;
> +
> +	if (host->reset) {
> +		if (mg_disk_init(host)) {
> +			end_request(req, 0);
> +			return;
> +		}
> +		host->reset = 0;
> +	}
> +
> +	if (mg_out(host, req->sector, req->nr_sectors, MG_CMD_RD, 0) != MG_ERR_NONE) {
> +		mg_bad_rw_intr(host);
> +	}
> +
> +	MG_DBG("requested %d sects (from %ld), buffer=0x%p\n", remains, req->sector, req->buffer);
> +
> +	while (remains) {
> +		if (mg_wait(host, MG_REG_STATUS_BIT_DATA_REQ, 3000) != MG_ERR_NONE) {
> +			mg_bad_rw_intr(host);
> +			return;
> +		}
> +		for (j = 0; j < MG_SECTOR_SIZE >> 1; j++) {
> +			*(u16 *)req->buffer = inw(host->dev_base + MG_BUFF_OFFSET + (j << 1));
> +			req->buffer += 2;
> +		}
> +
> +		req->sector++;
> +		req->errors = 0;
> +		remains = --req->nr_sectors;
> +		--req->current_nr_sectors;
> +
> +		if (req->current_nr_sectors <= 0) {
> +			MG_DBG("remain : %d sects\n", remains);
> +			end_request(req, 1);
> +			if (remains > 0) {
> +				req = elv_next_request(host->breq);
> +			}
> +		}
> +
> +		outb(MG_CMD_RD_CONF, host->dev_base + MG_REG_COMMAND);
> +	}
> +}
> +
> +static void mg_write(struct request *req)
> +{
> +	u32 remains, j;
> +	struct mg_host *host = req->rq_disk->private_data;
> +
> +	remains = req->nr_sectors;
> +
> +	if (host->reset) {
> +		if (mg_disk_init(host)) {
> +			end_request(req, 0);
> +			return;
> +		}
> +		host->reset = 0;
> +	}
> +
> +	if (mg_out(host, req->sector, req->nr_sectors, MG_CMD_WR, 0) != MG_ERR_NONE) {
> +		mg_bad_rw_intr(host);
> +		return;
> +	}
> +
> +
> +	MG_DBG("requested %d sects (from %ld), buffer=0x%p\n", remains, req->sector, req->buffer);
> +	while (remains) {
> +		if (mg_wait(host, MG_REG_STATUS_BIT_DATA_REQ, 3000) != MG_ERR_NONE) {
> +			mg_bad_rw_intr(host);
> +			return;
> +		}
> +		for (j = 0; j < MG_SECTOR_SIZE >> 1; j++) {
> +			outw(*(u16 *)req->buffer, host->dev_base + MG_BUFF_OFFSET + (j << 1));
> +			req->buffer += 2;
> +		}
> +		req->sector++;
> +		remains = --req->nr_sectors;
> +		--req->current_nr_sectors;
> +
> +		if (req->current_nr_sectors <= 0) {
> +			MG_DBG("remain : %d sects\n", remains);
> +			end_request(req, 1);
> +			if (remains > 0) {
> +				req = elv_next_request(host->breq);
> +			}
> +		}
> +
> +		outb(MG_CMD_WR_CONF, host->dev_base + MG_REG_COMMAND);
> +	}
> +}
> +
> +static void mg_read_intr(struct mg_host *host)
> +{
> +	u32 i;
> +	struct request *req;
> +
> +	/* check status */
> +	do {
> +		i = inb(host->dev_base + MG_REG_STATUS);
> +		if (i & MG_REG_STATUS_BIT_BUSY)
> +			break;
> +		if (!MG_READY_OK(i))
> +			break;
> +		if (i & MG_REG_STATUS_BIT_DATA_REQ)
> +			goto ok_to_read;
> +	} while (0);
> +	mg_dump_status("mg_read_intr", i, host);
> +	mg_bad_rw_intr(host);
> +	mg_request(host->breq);
> +	return;
> +
> +ok_to_read:
> +	/* get current segment of request */
> +	req = elv_next_request(host->breq);
> +
> +	/* read 1 sector */
> +	for (i = 0; i < MG_SECTOR_SIZE >> 1; i++) {
> +		*(u16 *)req->buffer = inw(host->dev_base + MG_BUFF_OFFSET + (i << 1));
> +		req->buffer += 2;
> +	}
> +
> +	/* manipulate request */
> +	MG_DBG("sector %ld, remaining=%ld, buffer=0x%p\n", req->sector, req->nr_sectors - 1, req->buffer);
> +
> +	req->sector++;
> +	req->errors = 0;
> +	i = --req->nr_sectors;
> +	--req->current_nr_sectors;
> +
> +	/* let know if current segment done */
> +	if (req->current_nr_sectors <= 0)
> +		end_request(req, 1);
> +
> +	/* set handler if read remains */
> +	if (i > 0) {
> +		host->mg_do_intr = mg_read_intr;
> +		mod_timer(&host->timer, jiffies + 3 * HZ);
> +	}
> +
> +	/* send read confirm */
> +	outb(MG_CMD_RD_CONF, host->dev_base + MG_REG_COMMAND);
> +
> +	/* goto next request */
> +	if (!i) {
> +		mg_request(host->breq);
> +	}
> +}
> +
> +static void mg_write_intr(struct mg_host *host)
> +{
> +	u32 i, j;
> +	u16 *buff;
> +	struct request *req;
> +
> +	/* get current segment of request */
> +	req = elv_next_request(host->breq);
> +
> +	/* check status */
> +	do {
> +		i = inb(host->dev_base + MG_REG_STATUS);
> +		if (i & MG_REG_STATUS_BIT_BUSY)
> +			break;
> +		if (!MG_READY_OK(i))
> +			break;
> +		if ((req->nr_sectors <= 1) || (i & MG_REG_STATUS_BIT_DATA_REQ))
> +			goto ok_to_write;
> +	} while (0);
> +	mg_dump_status("mg_write_intr", i, host);
> +	mg_bad_rw_intr(host);
> +	mg_request(host->breq);
> +	return;
> +
> +ok_to_write:
> +	/* manipulate request */
> +	req->sector++;
> +	i = --req->nr_sectors;
> +	--req->current_nr_sectors;
> +	req->buffer += MG_SECTOR_SIZE;
> +
> +	/* let know if current segment or all done */
> +	if (!i || (req->bio && req->current_nr_sectors <= 0))
> +		end_request(req, 1);
> +
> +	/* write 1 sector and set handler if remains */
> +	if (i > 0) {
> +		buff = (u16 *)req->buffer;
> +		for (j = 0; j < MG_STORAGE_BUFFER_SIZE >> 1; j++) {
> +			outw(*buff, host->dev_base + MG_BUFF_OFFSET + (j << 1));
> +			buff++;
> +		}
> +		MG_DBG("sector %ld, remaining=%ld, buffer=0x%p\n", req->sector, req->nr_sectors, req->buffer);
> +		host->mg_do_intr = mg_write_intr;
> +		mod_timer(&host->timer, jiffies + 3 * HZ);
> +	}
> +
> +	/* send write confirm */
> +	outb(MG_CMD_WR_CONF, host->dev_base + MG_REG_COMMAND);
> +
> +	if (!i) {
> +		mg_request(host->breq);
> +	}
> +}
> +
> +void mg_times_out(unsigned long data)
> +{
> +	struct mg_host *host = (struct mg_host *)data;
> +	char *name;
> +	struct request *req;
> +
> +	req = elv_next_request(host->breq);
> +	if (!req)
> +		return;
> +
> +	host->mg_do_intr = NULL;
> +
> +	name = req->rq_disk->disk_name;
> +	printk("%s: timeout\n", name);
> +
> +	host->error = MG_ERR_TIMEOUT;
> +	mg_bad_rw_intr(host);
> +
> +	mg_request(host->breq);
> +}
> +
> +static void mg_request_poll(struct request_queue *q)
> +{
> +	struct request *req;
> +	struct mg_host *host;
> +
> +	while ((req = elv_next_request(q)) != NULL) {
> +
> +		host = req->rq_disk->private_data;
> +
> +		if (blk_fs_request(req)) {
> +			switch (rq_data_dir(req)) {
> +			case READ:
> +				mg_read(req);
> +				break;
> +			case WRITE:
> +				mg_write(req);
> +				break;
> +			default:
> +				printk(KERN_WARNING "%s:%d unknown command\n", __func__, __LINE__);
> +				end_request(req, 0);
> +				break;
> +			}
> +		}
> +	}
> +}
> +
> +static unsigned int mg_issue_req(struct request *req,
> +					struct mg_host *host,
> +					unsigned int sect_num,
> +					unsigned int sect_cnt)
> +{
> +	u16 *buff;
> +	u32 i;
> +
> +	switch (rq_data_dir(req)) {
> +	case READ:
> +		if (mg_out(host, sect_num, sect_cnt, MG_CMD_RD, &mg_read_intr) != MG_ERR_NONE) {
> +			mg_bad_rw_intr(host);
> +			return host->error;
> +		}
> +		break;
> +	case WRITE:
> +		/* TODO : handler */
> +		outb(MG_REG_CTRL_INTR_DISABLE, host->dev_base + MG_REG_DRV_CTRL);
> +		if (mg_out(host, sect_num, sect_cnt, MG_CMD_WR, &mg_write_intr) != MG_ERR_NONE) {
> +			mg_bad_rw_intr(host);
> +			return host->error;
> +		}
> +		del_timer(&host->timer);
> +		mg_wait(host, MG_REG_STATUS_BIT_DATA_REQ, 3000);
> +		outb(MG_REG_CTRL_INTR_ENABLE, host->dev_base + MG_REG_DRV_CTRL);
> +		if (host->error) {
> +			mg_bad_rw_intr(host);
> +			return host->error;
> +		}
> +		buff = (u16 *)req->buffer;
> +		for (i = 0; i < MG_SECTOR_SIZE >> 1; i++) {
> +			outw(*buff, host->dev_base + MG_BUFF_OFFSET + (i << 1));
> +			buff++;
> +		}
> +		mod_timer(&host->timer, jiffies + 3 * HZ);
> +		outb(MG_CMD_WR_CONF, host->dev_base + MG_REG_COMMAND);
> +		break;
> +	default:
> +		printk(KERN_WARNING "%s:%d unknown command\n", __func__, __LINE__);
> +		end_request(req, 0);
> +		break;
> +	}
> +	return MG_ERR_NONE;
> +}
> +
> +/* This function also called from IRQ context */
> +static void mg_request(struct request_queue *q)
> +{
> +	struct request *req;
> +	struct mg_host *host;
> +	u32 sect_num, sect_cnt;
> +
> +	while (1) {
> +		req = elv_next_request(q);
> +		if (!req)
> +			return;
> +
> +		host = req->rq_disk->private_data;
> +
> +		/* check unwanted request call */
> +		if (host->mg_do_intr)
> +			return;
> +
> +		del_timer(&host->timer);
> +
> +		if (host->reset) {
> +			if (mg_disk_init(host)) {
> +				end_request(req, 0);
> +				return;
> +			}
> +			host->reset = 0;
> +		}
> +
> +		sect_num = req->sector;
> +		/* deal whole segments */
> +		sect_cnt = req->nr_sectors;
> +
> +		/* sanity check */
> +		if (sect_num >= get_capacity(req->rq_disk) ||
> +		    ((sect_num + sect_cnt) > get_capacity(req->rq_disk))) {
> +			printk(KERN_WARNING "%s: bad access: sector=%d, count=%d\n",
> +				 req->rq_disk->disk_name, sect_num, sect_cnt);
> +			end_request(req, 0);
> +			continue;
> +		}
> +
> +		if (!blk_fs_request(req))
> +			return;
> +
> +		if (!mg_issue_req(req, host, sect_num, sect_cnt))
> +			return;
> +	}
> +}
> +
> +static int mg_getgeo(struct block_device *bdev, struct hd_geometry *geo)
> +{
> +	struct mg_host *host = bdev->bd_disk->private_data;
> +
> +	geo->cylinders = host->id_data.cyls;
> +	geo->heads = host->id_data.heads;
> +	geo->sectors = host->id_data.sectors;
> +	return 0;
> +}
> +
> +static struct block_device_operations mg_disk_ops = {
> +	.getgeo = mg_getgeo
> +};
> +
> +static int mg_probe(struct platform_device *plat_dev)
> +{
> +	struct mg_host *host;
> +	struct resource *rsc;
> +	struct mg_drv_data *prv_data = plat_dev->dev.platform_data;
> +	int err = 0;
> +
> +	if (!prv_data) {
> +		printk(KERN_ERR "%s:%d fail (no driver_data)\n", __func__, __LINE__);
> +		err = -EINVAL;
> +		goto probe_err;
> +	}
> +
> +	/* alloc mg_host */
> +	host = kmalloc(sizeof(struct mg_host), GFP_KERNEL);
> +	if (!host) {
> +		printk(KERN_ERR "%s:%d fail (no memory for mg_host)\n", __func__, __LINE__);
> +		err = -ENOMEM;
> +		goto probe_err;
> +	}
> +	memset(host, 0, sizeof(struct mg_host));
> +	host->major = MG_DISK_MAJ;
> +
> +	/* link each other */
> +	prv_data->host = host;
> +	host->dev = &plat_dev->dev;
> +
> +	/* io remap */
> +	rsc = platform_get_resource(plat_dev, IORESOURCE_MEM, 0);
> +	if (!rsc) {
> +		printk(KERN_ERR "%s:%d platform_get_resource fail\n", __func__, __LINE__);
> +		err = -EINVAL;
> +		goto probe_err_2;
> +	}
> +	host->dev_base = (unsigned long)ioremap(rsc->start , rsc->end + 1);
> +	if (!host->dev_base) {
> +		printk(KERN_ERR "%s:%d ioremap fail\n", __func__, __LINE__);
> +		err = -EIO;
> +		goto probe_err_2;
> +	}
> +	MG_DBG("dev_base = 0x%x\n", (u32)host->dev_base);
> +
> +	/* disk init */
> +	err = mg_disk_init(host);
> +	if (err) {
> +		printk(KERN_ERR "%s:%d fail (err code : %d)\n", __func__, __LINE__, err);
> +		err = -EIO;
> +		goto probe_err_3;
> +	}
> +
> +	/* get irq resource */
> +	if (!prv_data->use_polling) {
> +		host->irq = platform_get_irq(plat_dev, 0);
> +		if (host->irq == -ENXIO) {
> +			err = host->irq;
> +			goto probe_err_3;
> +		}
> +		err = request_irq(host->irq, mg_irq, IRQF_DISABLED | IRQF_TRIGGER_RISING, MG_DEV_NAME, host);
> +		if (err) {
> +			printk(KERN_ERR "%s:%d fail (request_irq err=%d)\n", __func__, __LINE__, err);
> +			goto probe_err_3;
> +		}
> +
> +	}
> +
> +	/* get disk id */
> +	err = mg_get_disk_id(host);
> +	if (err) {
> +		printk(KERN_ERR "%s:%d fail (err code : %d)\n", __func__, __LINE__, err);
> +		err = -EIO;
> +		goto probe_err_4;
> +	}
> +
> +	err = register_blkdev(host->major, MG_DISK_NAME);
> +	if (err < 0) {
> +		printk(KERN_ERR "%s:%d (register_blkdev) fail (err code : %d)\n", __func__, __LINE__, err);
> +		goto probe_err_4;
> +	}
> +	err = 0;
> +	if (!host->major)
> +		host->major = err;
> +
> +	spin_lock_init(&host->lock);
> +
> +	if (prv_data->use_polling) {
> +		host->breq = blk_init_queue(mg_request_poll, &host->lock);
> +	} else {
> +		host->breq = blk_init_queue(mg_request, &host->lock);
> +	}
> +
> +	if (!host->breq) {
> +		err = -ENOMEM;
> +		printk(KERN_ERR "%s:%d (blk_init_queue) fail\n", __func__, __LINE__);
> +		goto probe_err_5;
> +	}
> +
> +	/* mflash is random device, thanx for the noop */
> +	elevator_exit(host->breq->elevator);
> +	err = elevator_init(host->breq, "noop");
> +	if (err) {
> +		printk(KERN_ERR "%s:%d (elevator_init) fail\n", __func__, __LINE__);
> +		goto probe_err_6;
> +	}
> +	blk_queue_max_sectors(host->breq, MG_MAX_SECTS);
> +	blk_queue_hardsect_size(host->breq, MG_SECTOR_SIZE);
> +
> +	init_timer(&host->timer);
> +	host->timer.function = mg_times_out;
> +	host->timer.data = (unsigned long)host;
> +
> +	host->gd = alloc_disk(MG_DISK_MAX_PART);
> +	if (!host->gd) {
> +		printk(KERN_ERR "%s:%d (alloc_disk) fail\n", __func__, __LINE__);
> +		err = -ENOMEM;
> +		goto probe_err_7;
> +	}
> +	host->gd->major = MG_DISK_MAJ;
> +	host->gd->first_minor = 0;
> +	host->gd->fops = &mg_disk_ops;
> +	host->gd->queue = host->breq;
> +	host->gd->private_data = host;
> +	sprintf(host->gd->disk_name, MG_DISK_NAME"a");
> +
> +	set_capacity(host->gd, host->tot_sectors);
> +
> +	add_disk(host->gd);
> +
> +	return err;
> +

I think below goto label enumeration is a not good. 
We need to change some good style. but Now, I don't 
have any good idea. 

> +probe_err_7:
> +	del_timer_sync(&host->timer);
> +probe_err_6:
> +	blk_cleanup_queue(host->breq);
> +probe_err_5:
> +	unregister_blkdev(MG_DISK_MAJ, MG_DISK_NAME);
> +probe_err_4:
> +	if (!prv_data->use_polling)
> +		free_irq(host->irq, host);
> +probe_err_3:
> +	iounmap((void __iomem *)host->dev_base);
> +probe_err_2:
> +	kfree(host);
> +probe_err:
> +	return err;
> +}
> +
> +static int mg_remove(struct platform_device *plat_dev)
> +{
> +	struct mg_drv_data *prv_data = plat_dev->dev.platform_data;
> +	struct mg_host *host = prv_data->host;
> +	int err = 0;
> +
> +	/* delete timer */
> +	del_timer_sync(&host->timer);
> +
> +	/* remove disk */
> +	if (host->gd) {
> +		del_gendisk(host->gd);
> +		put_disk(host->gd);
> +	}
> +	/* remove queue */
> +	if (host->breq)
> +		blk_cleanup_queue(host->breq);
> +
> +	/* unregister blk device */
> +	unregister_blkdev(host->major, MG_DISK_NAME);
> +
> +	/* free irq */
> +	if (!prv_data->use_polling)
> +		free_irq(host->irq, host);
> +
> +	/* unmap io */
> +	if (host->dev_base)
> +		iounmap((void __iomem *)host->dev_base);
> +
> +	/* free mg_host */
> +	if (host)
> +		kfree(host);
> +
> +	return err;
> +}
> +
> +static struct platform_driver mg_disk_driver = {
> +	.probe = mg_probe,
> +	.remove = mg_remove,
> +	.driver = {
> +		.name = MG_DEV_NAME,
> +		.owner = THIS_MODULE,
> +	}
> +};
> +
> +/****************************************************************************
> + *
> + * Module stuff
> + *
> + ****************************************************************************/
> +
> +static int __init mg_init(void)
> +{
> +	printk(KERN_INFO "mGine mflash driver, (c) 2008 mGine Co.\n");
> +	return platform_driver_register(&mg_disk_driver);
> +}
> +
> +static void __exit mg_exit(void)
> +{
> +	printk(KERN_INFO "mflash driver : bye bye\n");
> +	platform_driver_unregister(&mg_disk_driver);
> +}
> +
> +module_init(mg_init);
> +module_exit(mg_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("unsik Kim <donari75@xxxxxxxxx>");
> +MODULE_DESCRIPTION("mGine m[g]flash device driver");
> diff --git a/include/linux/mg_disk.h b/include/linux/mg_disk.h
> new file mode 100644
> index 0000000..df6bc04
> --- /dev/null
> +++ b/include/linux/mg_disk.h
> @@ -0,0 +1,174 @@
> +/*
> + *  include/linux/mg_disk.c
> + *
> + *  Support for the mGine m[g]flash IO mode.
> + *  Based on legacy hd.c
> + *
> + * (c) 2008 mGine Co.,LTD
> + * (c) 2008 unsik Kim <donari75@xxxxxxxxx>
> + *
> + *  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.
> + */
> +
> +#ifndef __MG_DISK_H__
> +#define __MG_DISK_H__
> +
> +#include <linux/blkdev.h>
> +#include <linux/hdreg.h>
> +
> +/* name for block device */
> +#define MG_DISK_NAME "mgd"
> +/* name for platform device */
> +#define MG_DEV_NAME "mg_disk"
> +
> +#define MG_DISK_MAJ 240
> +#define MG_DISK_MAX_PART 16
> +#define MG_SECTOR_SIZE 512
> +#define MG_MAX_SECTS 256
> +
> +/* Register offsets */
> +#define MG_BUFF_OFFSET			0x8000
> +#define MG_STORAGE_BUFFER_SIZE	0x200
> +#define MG_REG_OFFSET			0xC000
> +#define MG_REG_FEATURE			(MG_REG_OFFSET + 2)	/* write case */
> +#define MG_REG_ERROR			(MG_REG_OFFSET + 2)	/* read case */
> +#define MG_REG_SECT_CNT			(MG_REG_OFFSET + 4)
> +#define MG_REG_SECT_NUM			(MG_REG_OFFSET + 6)
> +#define MG_REG_CYL_LOW			(MG_REG_OFFSET + 8)
> +#define MG_REG_CYL_HIGH			(MG_REG_OFFSET + 0xA)
> +#define MG_REG_DRV_HEAD			(MG_REG_OFFSET + 0xC)
> +#define MG_REG_COMMAND			(MG_REG_OFFSET + 0xE)	/* write case */
> +#define MG_REG_STATUS			(MG_REG_OFFSET + 0xE)	/* read  case */
> +#define MG_REG_DRV_CTRL			(MG_REG_OFFSET + 0x10)
> +#define MG_REG_BURST_CTRL		(MG_REG_OFFSET + 0x12)
> +
> +/* "Drive Select/Head Register" bit values */
> +#define MG_REG_HEAD_MUST_BE_ON	0xA0 /* These 2 bits are always on */
> +#define MG_REG_HEAD_DRIVE_MASTER	(0x00 | MG_REG_HEAD_MUST_BE_ON)
> +#define MG_REG_HEAD_DRIVE_SLAVE	(0x10 | MG_REG_HEAD_MUST_BE_ON)
> +#define MG_REG_HEAD_LBA_MODE		(0x40 | MG_REG_HEAD_MUST_BE_ON)
> +
> +
> +/* "Device Control Register" bit values */
> +#define MG_REG_CTRL_INTR_ENABLE		0x0
> +#define MG_REG_CTRL_INTR_DISABLE		(0x1<<1)
> +#define MG_REG_CTRL_RESET			(0x1<<2)
> +#define MG_REG_CTRL_INTR_POLA_ACTIVE_HIGH	0x0
> +#define MG_REG_CTRL_INTR_POLA_ACTIVE_LOW	(0x1<<4)
> +#define MG_REG_CTRL_DPD_POLA_ACTIVE_LOW	0x0
> +#define MG_REG_CTRL_DPD_POLA_ACTIVE_HIGH	(0x1<<5)
> +#define MG_REG_CTRL_DPD_DISABLE		0x0
> +#define MG_REG_CTRL_DPD_ENABLE		(0x1<<6)
> +
> +/* Status register bit */
> +#define MG_REG_STATUS_BIT_ERROR			0x01 /* error bit in status register */
> +#define MG_REG_STATUS_BIT_CORRECTED_ERROR		0x04 /* corrected error in status register */
> +#define MG_REG_STATUS_BIT_DATA_REQ			0x08 /* data request bit in status register */
> +#define MG_REG_STATUS_BIT_SEEK_DONE			0x10 /* DSC - Drive Seek Complete */
> +#define MG_REG_STATUS_BIT_WRITE_FAULT		0x20 /* DWF - Drive Write Fault */
> +#define MG_REG_STATUS_BIT_READY			0x40
> +#define MG_REG_STATUS_BIT_BUSY			0x80
> +
> +/* handy status */
> +#define MG_STAT_READY		(MG_REG_STATUS_BIT_READY | MG_REG_STATUS_BIT_SEEK_DONE)
> +#define MG_READY_OK(s)		(((s) & (MG_STAT_READY | \
> +					(MG_REG_STATUS_BIT_BUSY | MG_REG_STATUS_BIT_WRITE_FAULT | MG_REG_STATUS_BIT_ERROR))) \
> +					== MG_STAT_READY)
> +
> +/* Error register */
> +#define MG_REG_ERR_AMNF		0x01
> +#define MG_REG_ERR_ABRT		0x04
> +#define MG_REG_ERR_IDNF		0x10
> +#define MG_REG_ERR_UNC		0x40
> +#define MG_REG_ERR_BBK		0x80
> +
> +/* error code for others */
> +#define MG_ERR_NONE 0
> +#define MG_ERR_TIMEOUT 0x100
> +#define MG_ERR_INIT_STAT 0x101
> +#define MG_ERR_TRANSLATION 0x102
> +#define MG_ERR_CTRL_RST 0x103
> +
> +#define MG_MAX_ERRORS	16	/* Max read/write errors/sector */
> +#define MG_RESET_FREQ	4	/* Reset controller every 4th retry */
> +
> +/* command */
> +#define MG_CMD_RD 0x20
> +#define MG_CMD_WR 0x30
> +#define MG_CMD_SLEEP 0x99
> +#define MG_CMD_WAKEUP 0xC3
> +#define MG_CMD_ID 0xEC
> +#define MG_CMD_WR_CONF 0x3C
> +#define MG_CMD_RD_CONF 0x40
> +
> +/* private driver data */
> +struct mg_drv_data {
> +	/* disk resource */
> +	u32 nr_chips;
> +	u32 op_mode;
> +#define MG_OP_CASCADE (1 << 0)
> +#define MG_OP_CASCADE_SYNC_RD (1 << 1)
> +#define MG_OP_CASCADE_SYNC_WR (1 << 2)
> +#define MG_OP_INTERLEAVE (1 << 3)
> +
> +	u32 use_polling;
> +
> +	/* synchronous mode */
> +	u16	burst_latcy;
> +#define MG_BURST_LAT_4 (3 << 4)
> +#define MG_BURST_LAT_5 (4 << 4)
> +#define MG_BURST_LAT_6 (5 << 4)
> +#define MG_BURST_LAT_7 (6 << 4)
> +#define MG_BURST_LAT_8 (7 << 4)
> +	u16	burst_len;
> +#define MG_BURST_LEN_4 (1 << 1)
> +#define MG_BURST_LEN_8 (2 << 1)
> +#define MG_BURST_LEN_16 (3 << 1)
> +#define MG_BURST_LEN_32 (4 << 1)
> +#define MG_BURST_LEN_CONT (0 << 1)
> +
> +	/* control pin resource */
> +	int (*mg_ctrl_pin_init) (void); /* initialize hdrst, wd, dpd pin to GPIO and output high */
> +	void (*mg_hdrst_pin) (u8 level);
> +	void (*mg_wp_pin) (u8 level);
> +	void (*mg_dpd_pin) (u8 level);
> +
> +	/* internally used */
> +	struct mg_host *host;
> +};
> +
> +/* main structure for mflash driver */
> +struct mg_host {
> +	struct device *dev;
> +
> +	struct request_queue *breq;
> +	spinlock_t lock;
> +	struct gendisk *gd;
> +
> +	struct timer_list timer;
> +	void (*mg_do_intr) (struct mg_host *);
> +
> +	struct hd_driveid id_data;
> +	u32 tot_sectors;
> +
> +	unsigned long dev_base;
> +	unsigned int irq;
> +
> +	u32 major;
> +	u32 error;
> +	u32 reset;
> +};
> +
> +/*
> + * Debugging macro and defines
> + */
> +#undef DO_MG_DEBUG
> +#ifdef DO_MG_DEBUG
> +#  define MG_DBG(fmt, args...) printk(KERN_DEBUG "%s:%d "fmt, __func__, __LINE__, ##args)
> +#else /* CONFIG_MG_DEBUG */
> +#  define MG_DBG(fmt, args...) do { } while (0)
> +#endif /* CONFIG_MG_DEBUG */
> +
> +#endif
> -- 
> 1.5.4.3
> 



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