Samsung S3C24xx SD/MMC driver
From: 	 	Harald Welte <laforge@openmoko.org>
To: 	 	linux-kernel@vger.kernel.org
Subject: 	 	[PATCH] Samsung S3C24xx SD/MMC driver
Date: 	 	Wed, 19 Dec 2007 15:22:13 +0100
Message-ID: 	 	<20071219142213.GD29882@prithivi.gnumonks.org>
Cc: 	 	drzeus-mmc@drzeus.cx, tk@maintech.de, ben-linux@fluff.org
Archive-link: 	 	Article, Thread

Hi!

This is a MMC/SD driver for the Samsung S3C24xx SD/MMC controller, originally
developed years ago by Thomas Kleffel <tk@maintech.de>.

Due to time constraints, he had no time to further maintain the driver
and follow the mainline Linux changes in the SD/MMC stack.

With his authorization, I have taken over the task of making it
compliant to the current mainline SD/MMC API and take care of the
mainline kernel merge.

So please advise on whatever changes you deem neccessary and I'll try to
do my best to incorporate them for a hopefully not-too-distant mainline
merge.

After a potential kernel inclusion, we would co-maintain the driver.

Acked-by: Thomas Kleffel <tk@maintech.de>
Signed-off-by: Harald Welte <laforge@openmoko.org>

---

Index: linux-2.6/include/asm-arm/arch-s3c2410/regs-sdi.h
===================================================================
--- linux-2.6.orig/include/asm-arm/arch-s3c2410/regs-sdi.h
+++ linux-2.6/include/asm-arm/arch-s3c2410/regs-sdi.h
@@ -28,9 +28,15 @@
 #define S3C2410_SDIDCNT               (0x30)
 #define S3C2410_SDIDSTA               (0x34)
 #define S3C2410_SDIFSTA               (0x38)
+
 #define S3C2410_SDIDATA               (0x3C)
 #define S3C2410_SDIIMSK               (0x40)
 
+#define S3C2440_SDIDATA               (0x40)
+#define S3C2440_SDIIMSK               (0x3C)
+
+#define S3C2440_SDICON_SDRESET        (1<<8)
+#define S3C2440_SDICON_MMCCLOCK       (1<<5)
 #define S3C2410_SDICON_BYTEORDER      (1<<4)
 #define S3C2410_SDICON_SDIOIRQ        (1<<3)
 #define S3C2410_SDICON_RWAITEN        (1<<2)
@@ -42,7 +48,8 @@
 #define S3C2410_SDICMDCON_LONGRSP     (1<<10)
 #define S3C2410_SDICMDCON_WAITRSP     (1<<9)
 #define S3C2410_SDICMDCON_CMDSTART    (1<<8)
-#define S3C2410_SDICMDCON_INDEX       (0xff)
+#define S3C2410_SDICMDCON_SENDERHOST  (1<<6)
+#define S3C2410_SDICMDCON_INDEX       (0x3f)
 
 #define S3C2410_SDICMDSTAT_CRCFAIL    (1<<12)
 #define S3C2410_SDICMDSTAT_CMDSENT    (1<<11)
@@ -51,6 +58,9 @@
 #define S3C2410_SDICMDSTAT_XFERING    (1<<8)
 #define S3C2410_SDICMDSTAT_INDEX      (0xff)
 
+#define S3C2440_SDIDCON_DS_BYTE       (0<<22)
+#define S3C2440_SDIDCON_DS_HALFWORD   (1<<22)
+#define S3C2440_SDIDCON_DS_WORD       (2<<22)
 #define S3C2410_SDIDCON_IRQPERIOD     (1<<21)
 #define S3C2410_SDIDCON_TXAFTERRESP   (1<<20)
 #define S3C2410_SDIDCON_RXAFTERCMD    (1<<19)
@@ -59,6 +69,7 @@
 #define S3C2410_SDIDCON_WIDEBUS       (1<<16)
 #define S3C2410_SDIDCON_DMAEN         (1<<15)
 #define S3C2410_SDIDCON_STOP          (1<<14)
+#define S3C2440_SDIDCON_DATSTART      (1<<14)
 #define S3C2410_SDIDCON_DATMODE	      (3<<12)
 #define S3C2410_SDIDCON_BLKNUM        (0x7ff)
 
@@ -68,6 +79,7 @@
 #define S3C2410_SDIDCON_XFER_RXSTART  (2<<12)
 #define S3C2410_SDIDCON_XFER_TXSTART  (3<<12)
 
+#define S3C2410_SDIDCON_BLKNUM_MASK   (0xFFF)
 #define S3C2410_SDIDCNT_BLKNUM_SHIFT  (12)
 
 #define S3C2410_SDIDSTA_RDYWAITREQ    (1<<10)
@@ -82,10 +94,12 @@
 #define S3C2410_SDIDSTA_TXDATAON      (1<<1)
 #define S3C2410_SDIDSTA_RXDATAON      (1<<0)
 
+#define S3C2440_SDIFSTA_FIFORESET      (1<<16)
+#define S3C2440_SDIFSTA_FIFOFAIL       (3<<14)  /* 3 is correct (2 bits) */
 #define S3C2410_SDIFSTA_TFDET          (1<<13)
 #define S3C2410_SDIFSTA_RFDET          (1<<12)
-#define S3C2410_SDIFSTA_TXHALF         (1<<11)
-#define S3C2410_SDIFSTA_TXEMPTY        (1<<10)
+#define S3C2410_SDIFSTA_TFHALF         (1<<11)
+#define S3C2410_SDIFSTA_TFEMPTY        (1<<10)
 #define S3C2410_SDIFSTA_RFLAST         (1<<9)
 #define S3C2410_SDIFSTA_RFFULL         (1<<8)
 #define S3C2410_SDIFSTA_RFHALF         (1<<7)
Index: linux-2.6/drivers/mmc/host/s3cmci.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/mmc/host/s3cmci.c
@@ -0,0 +1,1409 @@
+/*
+ *  linux/drivers/mmc/s3cmci.h - Samsung S3C MCI driver
+ *
+ *  Copyright (C) 2004-2006 maintech GmbH, Thomas Kleffel <tk@maintech.de>
+ *  Copyright (C) 2007 OpenMoko, Inc., Harald Welte <laforge@openmoko.org>
+ *
+ * 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/dma-mapping.h>
+#include <linux/clk.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/host.h>
+#include <linux/platform_device.h>
+#include <linux/irq.h>
+
+#include <asm/dma.h>
+#include <asm/dma-mapping.h>
+
+#include <asm/io.h>
+#include <asm/arch/regs-sdi.h>
+#include <asm/arch/regs-gpio.h>
+#include <asm/arch/mci.h>
+
+#include "s3cmci.h"
+
+#define DRIVER_NAME "s3c-mci"
+
+enum dbg_channels {
+	dbg_err   = (1 << 0),
+	dbg_debug = (1 << 1),
+	dbg_info  = (1 << 2),
+	dbg_irq   = (1 << 3),
+	dbg_sg    = (1 << 4),
+	dbg_dma   = (1 << 5),
+	dbg_pio   = (1 << 6),
+	dbg_fail  = (1 << 7),
+	dbg_conf  = (1 << 8),
+};
+
+static const int dbgmap_err   = dbg_err | dbg_fail;
+static const int dbgmap_info  = dbg_info | dbg_conf;
+static const int dbgmap_debug = dbg_debug;
+
+#define dbg(host, channels, args...)		 \
+	do {					 \
+	if (dbgmap_err & channels) 		 \
+		dev_err(&host->pdev->dev, args); \
+	else if (dbgmap_info & channels)	 \
+		dev_info(&host->pdev->dev, args);\
+	else if (dbgmap_debug & channels)	 \
+		dev_dbg(&host->pdev->dev, args); \
+	} while (0)
+
+#define RESSIZE(ressource) (((ressource)->end - (ressource)->start)+1)
+
+static struct s3c2410_dma_client s3cmci_dma_client = {
+	.name		= "s3c-mci",
+};
+
+static void finalize_request(struct s3cmci_host *host);
+static void s3cmci_send_request(struct mmc_host *mmc);
+static void s3cmci_reset(struct s3cmci_host *host);
+
+#ifdef CONFIG_MMC_DEBUG
+
+static char *mmc_cmd2str(int cmd)
+{
+	switch (cmd) {
+	case  0: return "GO_IDLE_STATE";
+	case  1: return "ALL_SEND_OCR";
+	case  2: return "ALL_SEND_CID";
+	case  3: return "ALL_SEND_RELATIVE_ADD";
+	case  6: return "ACMD: SD_SET_BUSWIDTH";
+	case  7: return "SEL_DESEL_CARD";
+	case  9: return "SEND_CSD";
+	case 10: return "SEND_CID";
+	case 11: return "READ_UNTIL_STOP";
+	case 12: return "STOP_TRANSMISSION";
+	case 13: return "SEND_STATUS";
+	case 15: return "GO_INACTIVE_STATE";
+	case 16: return "SET_BLOCKLEN";
+	case 17: return "READ_SINGLE_BLOCK";
+	case 18: return "READ_MULTIPLE_BLOCK";
+	case 24: return "WRITE_SINGLE_BLOCK";
+	case 25: return "WRITE_MULTIPLE_BLOCK";
+	case 41: return "ACMD: SD_APP_OP_COND";
+	case 55: return "APP_CMD";
+	default: return "UNKNOWN";
+	}
+}
+
+static char *mmc_err2str(int err)
+{
+	switch (err) {
+	case 0:			return "OK";
+	case -ETIMEDOUT:	return "TIMEOUT";
+	case -EILSEQ: 		return "BADCRC";
+	case -EINVAL: 		return "EINVAL";
+	case -ENOMEDIUM: 	return "NOMEDIUM";
+	default:		return "UNKNOWN";
+	}
+}
+
+static inline void dbg_dumpregs(struct s3cmci_host *host, char *prefix)
+{
+	u32 con, pre, cmdarg, cmdcon, cmdsta, r0, r1, r2, r3, timer, bsize;
+	u32 datcon, datcnt, datsta, fsta, imask;
+
+	con 	= readl(host->base + S3C2410_SDICON);
+	pre 	= readl(host->base + S3C2410_SDIPRE);
+	cmdarg 	= readl(host->base + S3C2410_SDICMDARG);
+	cmdcon 	= readl(host->base + S3C2410_SDICMDCON);
+	cmdsta 	= readl(host->base + S3C2410_SDICMDSTAT);
+	r0 	= readl(host->base + S3C2410_SDIRSP0);
+	r1 	= readl(host->base + S3C2410_SDIRSP1);
+	r2 	= readl(host->base + S3C2410_SDIRSP2);
+	r3 	= readl(host->base + S3C2410_SDIRSP3);
+	timer 	= readl(host->base + S3C2410_SDITIMER);
+	bsize 	= readl(host->base + S3C2410_SDIBSIZE);
+	datcon 	= readl(host->base + S3C2410_SDIDCON);
+	datcnt 	= readl(host->base + S3C2410_SDIDCNT);
+	datsta 	= readl(host->base + S3C2410_SDIDSTA);
+	fsta 	= readl(host->base + S3C2410_SDIFSTA);
+	imask   = readl(host->base + host->sdiimsk);
+
+	dbg(host, dbg_debug, "%s  CON:[%08x]  PRE:[%08x]  TMR:[%08x]\n",
+				prefix, con, pre, timer);
+
+	dbg(host, dbg_debug, "%s CCON:[%08x] CARG:[%08x] CSTA:[%08x]\n",
+				prefix, cmdcon, cmdarg, cmdsta);
+
+	dbg(host, dbg_debug, "%s DCON:[%08x] FSTA:[%08x]"
+			       " DSTA:[%08x] DCNT:[%08x]\n",
+				prefix, datcon, fsta, datsta, datcnt);
+
+	dbg(host, dbg_debug, "%s   R0:[%08x]   R1:[%08x]"
+			       "   R2:[%08x]   R3:[%08x]\n",
+				prefix, r0, r1, r2, r3);
+}
+
+static void prepare_dbgmsg(struct s3cmci_host *host, struct mmc_command *cmd,
+								int stop)
+{
+	snprintf(host->dbgmsg_cmd, 300,
+		"#%u%s op:%s(%i) arg:0x%08x flags:0x08%x retries:%u",
+		host->ccnt, (stop?" (STOP)":""), mmc_cmd2str(cmd->opcode),
+		cmd->opcode, cmd->arg, cmd->flags, cmd->retries);
+
+	if (cmd->data) {
+		snprintf(host->dbgmsg_dat, 300,
+			"#%u bsize:%u blocks:%u bytes:%u",
+			host->dcnt, cmd->data->blksz,
+			cmd->data->blocks,
+			cmd->data->blocks * cmd->data->blksz);
+	} else {
+		host->dbgmsg_dat[0] = '\0';
+	}
+}
+
+static void dbg_dumpcmd(struct s3cmci_host *host, struct mmc_command *cmd,
+								int fail)
+{
+	unsigned int dbglvl = fail?dbg_fail:dbg_debug;
+
+	if (!cmd)
+		return;
+
+	if (cmd->error == 0) {
+
+		dbg(host, dbglvl, "CMD[OK] %s R0:0x%08x\n",
+			host->dbgmsg_cmd, cmd->resp[0]);
+	} else {
+		dbg(host, dbglvl, "CMD[%s] %s Status:%s\n",
+			mmc_err2str(cmd->error), host->dbgmsg_cmd,
+			host->status);
+	}
+
+	if (!cmd->data)
+		return;
+
+	if (cmd->data->error == 0) {
+		dbg(host, dbglvl, "DAT[%s] %s\n",
+			mmc_err2str(cmd->data->error), host->dbgmsg_dat);
+	} else {
+		dbg(host, dbglvl, "DAT[%s] %s DCNT:0x%08x\n",
+			mmc_err2str(cmd->data->error), host->dbgmsg_dat,
+			readl(host->base + S3C2410_SDIDCNT));
+	}
+}
+#endif
+
+static inline u32 enable_imask(struct s3cmci_host *host, u32 imask)
+{
+	u32 newmask;
+
+	newmask = readl(host->base + host->sdiimsk);
+	newmask |= imask;
+
+	writel(newmask, host->base + host->sdiimsk);
+
+	return newmask;
+}
+
+static inline u32 disable_imask(struct s3cmci_host *host, u32 imask)
+{
+	u32 newmask;
+
+	newmask = readl(host->base + host->sdiimsk);
+	newmask &= ~imask;
+
+	writel(newmask, host->base + host->sdiimsk);
+
+	return newmask;
+}
+
+static inline void clear_imask(struct s3cmci_host *host)
+{
+	writel(0, host->base + host->sdiimsk);
+}
+
+static inline int get_data_buffer(struct s3cmci_host *host,
+				  u32 *words, u32 **pointer)
+{
+	struct scatterlist *sg;
+
+	if (host->pio_active == XFER_NONE)
+		return -EINVAL;
+
+	if ((!host->mrq) || (!host->mrq->data))
+		return -EINVAL;
+
+	if (host->pio_sgptr >= host->mrq->data->sg_len) {
+		dbg(host, dbg_debug, "no more buffers (%i/%i)\n",
+		      host->pio_sgptr, host->mrq->data->sg_len);
+		return -EBUSY;
+	}
+	sg = &host->mrq->data->sg[host->pio_sgptr];
+
+	*words = sg->length >> 2;
+	*pointer = page_address(sg_page(sg)) + sg->offset;
+
+	host->pio_sgptr++;
+
+	dbg(host, dbg_sg, "new buffer (%i/%i)\n",
+	      host->pio_sgptr, host->mrq->data->sg_len);
+
+	return 0;
+}
+
+#define FIFO_FILL(host) ((readl(host->base + S3C2410_SDIFSTA) & 	\
+				S3C2410_SDIFSTA_COUNTMASK) >> 2)
+#define FIFO_FREE(host) ((63 - (readl(host->base + S3C2410_SDIFSTA) 	\
+				& S3C2410_SDIFSTA_COUNTMASK)) >> 2)
+
+static inline void do_pio_read(struct s3cmci_host *host)
+{
+	int res;
+	u32 fifo;
+	void __iomem *from_ptr;
+
+	/* write real prescaler to host, it might be set slow to fix */
+	writel(host->prescaler, host->base + S3C2410_SDIPRE);
+
+	from_ptr = host->base + host->sdidata;
+
+	while ((fifo = FIFO_FILL(host))) {
+		if (!host->pio_words) {
+			res = get_data_buffer(host, &host->pio_words,
+							&host->pio_ptr);
+			if (res) {
+				host->pio_active = XFER_NONE;
+				host->complete_what = COMPLETION_FINALIZE;
+
+				dbg(host, dbg_pio, "pio_read(): "
+				    "complete (no more data).\n");
+				return;
+			}
+
+			dbg(host, dbg_pio, "pio_read(): new target: "
+			    "[%i]@[%p]\n", host->pio_words, host->pio_ptr);
+		}
+
+		dbg(host, dbg_pio, "pio_read(): fifo:[%02i] "
+		    "buffer:[%03i] dcnt:[%08X]\n", fifo, host->pio_words,
+		    readl(host->base + S3C2410_SDIDCNT));
+
+		if (fifo > host->pio_words)
+			fifo = host->pio_words;
+
+		host->pio_words -= fifo;
+		host->pio_count += fifo;
+
+		while (fifo--)
+			*(host->pio_ptr++) = readl(from_ptr);
+	}
+
+	if (!host->pio_words) {
+		res = get_data_buffer(host, &host->pio_words, &host->pio_ptr);
+		if (res) {
+			dbg(host, dbg_pio, "pio_read(): "
+			    "complete (no more buffers).\n");
+			host->pio_active = XFER_NONE;
+			host->complete_what = COMPLETION_FINALIZE;
+
+			return;
+		}
+	}
+
+	enable_imask(host, S3C2410_SDIIMSK_RXFIFOHALF
+						| S3C2410_SDIIMSK_RXFIFOLAST);
+}
+
+static inline void do_pio_write(struct s3cmci_host *host)
+{
+	int res;
+	u32 fifo;
+
+	void __iomem *to_ptr;
+
+	to_ptr = host->base + host->sdidata;
+
+	while ((fifo = FIFO_FREE(host))) {
+		if (!host->pio_words) {
+			res = get_data_buffer(host, &host->pio_words,
+							&host->pio_ptr);
+			if (res) {
+				dbg(host, dbg_pio, "pio_write(): "
+					"complete (no more data).\n");
+				host->pio_active = XFER_NONE;
+
+				return;
+			}
+
+			dbg(host, dbg_pio, "pio_write(): "
+				"new source: [%i]@[%p]\n",
+				host->pio_words, host->pio_ptr);
+
+		}
+
+		if (fifo > host->pio_words)
+			fifo = host->pio_words;
+
+		host->pio_words -= fifo;
+		host->pio_count += fifo;
+
+		while (fifo--)
+			writel(*(host->pio_ptr++), to_ptr);
+	}
+
+	enable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
+}
+
+static void pio_tasklet(unsigned long data)
+{
+	struct s3cmci_host *host = (struct s3cmci_host *) data;
+
+	disable_irq(host->irq);
+
+	if (host->pio_active == XFER_WRITE)
+		do_pio_write(host);
+
+	if (host->pio_active == XFER_READ)
+		do_pio_read(host);
+
+	if (host->complete_what == COMPLETION_FINALIZE) {
+		clear_imask(host);
+		if (host->pio_active != XFER_NONE) {
+			dbg(host, dbg_err, "unfinished %s "
+				"- pio_count:[%u] pio_words:[%u]\n",
+				(host->pio_active == XFER_READ)?"read":"write",
+				host->pio_count, host->pio_words);
+
+			host->mrq->data->error = -EIO;
+		}
+
+		finalize_request(host);
+	} else
+		enable_irq(host->irq);
+}
+
+/*
+ * ISR for SDI Interface IRQ
+ * Communication between driver and ISR works as follows:
+ *   host->mrq 			points to current request
+ *   host->complete_what	tells ISR when the request is considered done
+ *     COMPLETION_CMDSENT	  when the command was sent
+ *     COMPLETION_RSPFIN          when a response was received
+ *     COMPLETION_XFERFINISH	  when the data transfer is finished
+ *     COMPLETION_XFERFINISH_RSPFIN both of the above.
+ *   host->complete_request	is the completion-object the driver waits for
+ *
+ * 1) Driver sets up host->mrq and host->complete_what
+ * 2) Driver prepares the transfer
+ * 3) Driver enables interrupts
+ * 4) Driver starts transfer
+ * 5) Driver waits for host->complete_rquest
+ * 6) ISR checks for request status (errors and success)
+ * 6) ISR sets host->mrq->cmd->error and host->mrq->data->error
+ * 7) ISR completes host->complete_request
+ * 8) ISR disables interrupts
+ * 9) Driver wakes up and takes care of the request
+ *
+ * Note: "->error"-fields are expected to be set to 0 before the request
+ *       was issued by mmc.c - therefore they are only set, when an error
+ *       contition comes up
+ */
+
+static irqreturn_t s3cmci_irq(int irq, void *dev_id)
+{
+	struct s3cmci_host *host;
+	struct mmc_command *cmd;
+	u32 mci_csta, mci_dsta, mci_fsta, mci_dcnt, mci_imsk;
+	u32 mci_cclear, mci_dclear;
+	unsigned long iflags;
+
+	host = (struct s3cmci_host *)dev_id;
+
+	spin_lock_irqsave(&host->complete_lock, iflags);
+
+	mci_csta 	= readl(host->base + S3C2410_SDICMDSTAT);
+	mci_dsta 	= readl(host->base + S3C2410_SDIDSTA);
+	mci_dcnt 	= readl(host->base + S3C2410_SDIDCNT);
+	mci_fsta 	= readl(host->base + S3C2410_SDIFSTA);
+	mci_imsk	= readl(host->base + host->sdiimsk);
+	mci_cclear	= 0;
+	mci_dclear	= 0;
+
+	if ((host->complete_what == COMPLETION_NONE) ||
+			(host->complete_what == COMPLETION_FINALIZE)) {