atmel-mci: Driver for Atmel on-chip MMC controllers

This is a driver for the MMC controller on the AP7000 chips from
Atmel. It should in theory work on AT91 systems too with some
tweaking, but since the DMA interface is quite different, it's not
entirely clear if it's worth merging this with the at91_mci driver.

This driver has been around for a while in BSPs and kernel sources
provided by Atmel, but this particular version uses the generic DMA
Engine framework (with the slave extensions) instead of an
avr32-only DMA controller framework.

This driver can also use PIO transfers when no DMA channels are
available, and for transfers where using DMA may be difficult or
impractical for some reason (e.g. the DMA setup overhead is usually
not worth it for very short transfers, and badly aligned buffers or
lengths are difficult to handle.)

Currently, the driver only support PIO transfers. DMA support has been
split out to a separate patch to hopefully make it easier to review.

The driver has been tested using mmc-block and ext3fs on several SD,
SDHC and MMC+ cards. Reads and writes work fine, with read transfer
rates up to 3.5 MiB/s on fast cards with debugging disabled.

The driver has also been tested using the mmc_test module on the same
cards. All tests except 7, 9, 15 and 17 succeed. The first two are
unsupported by all the cards I have, so I don't know if the driver
handles this correctly. The last two fail because the hardware flags a
Data CRC Error instead of a Data Timeout error. I'm not sure how to deal
with that.

Documentation for this controller can be found in many data sheets from
Atmel, including the AT32AP7000 data sheet which can be found here:

http://www.atmel.com/dyn/products/datasheets.asp?family_id=682

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 91 insertions, 0 deletions

diff --git a/drivers/mmc/host/atmel-mci-regs.h b/drivers/mmc/host/atmel-mci-regs.h
new file mode 100644
index 00000000000..a9a5657706c
--- /dev/null
+++ b/drivers/mmc/host/atmel-mci-regs.h
@@ -0,0 +1,91 @@
+/*
+ * Atmel MultiMedia Card Interface driver
+ *
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * 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 __DRIVERS_MMC_ATMEL_MCI_H__
+#define __DRIVERS_MMC_ATMEL_MCI_H__
+
+/* MCI Register Definitions */
+#define MCI_CR			0x0000	/* Control */
+# define MCI_CR_MCIEN		(  1 <<  0)	/* MCI Enable */
+# define MCI_CR_MCIDIS		(  1 <<  1)	/* MCI Disable */
+# define MCI_CR_SWRST		(  1 <<  7)	/* Software Reset */
+#define MCI_MR			0x0004	/* Mode */
+# define MCI_MR_CLKDIV(x)	((x) <<  0)	/* Clock Divider */
+# define MCI_MR_RDPROOF		(  1 << 11)	/* Read Proof */
+# define MCI_MR_WRPROOF		(  1 << 12)	/* Write Proof */
+#define MCI_DTOR		0x0008	/* Data Timeout */
+# define MCI_DTOCYC(x)		((x) <<  0)	/* Data Timeout Cycles */
+# define MCI_DTOMUL(x)		((x) <<  4)	/* Data Timeout Multiplier */
+#define MCI_SDCR		0x000c	/* SD Card / SDIO */
+# define MCI_SDCSEL_SLOT_A	(  0 <<  0)	/* Select SD slot A */
+# define MCI_SDCSEL_SLOT_B	(  1 <<  0)	/* Select SD slot A */
+# define MCI_SDCBUS_1BIT	(  0 <<  7)	/* 1-bit data bus */
+# define MCI_SDCBUS_4BIT	(  1 <<  7)	/* 4-bit data bus */
+#define MCI_ARGR		0x0010	/* Command Argument */
+#define MCI_CMDR		0x0014	/* Command */
+# define MCI_CMDR_CMDNB(x)	((x) <<  0)	/* Command Opcode */
+# define MCI_CMDR_RSPTYP_NONE	(  0 <<  6)	/* No response */
+# define MCI_CMDR_RSPTYP_48BIT	(  1 <<  6)	/* 48-bit response */
+# define MCI_CMDR_RSPTYP_136BIT	(  2 <<  6)	/* 136-bit response */
+# define MCI_CMDR_SPCMD_INIT	(  1 <<  8)	/* Initialization command */
+# define MCI_CMDR_SPCMD_SYNC	(  2 <<  8)	/* Synchronized command */
+# define MCI_CMDR_SPCMD_INT	(  4 <<  8)	/* Interrupt command */
+# define MCI_CMDR_SPCMD_INTRESP	(  5 <<  8)	/* Interrupt response */
+# define MCI_CMDR_OPDCMD	(  1 << 11)	/* Open Drain */
+# define MCI_CMDR_MAXLAT_5CYC	(  0 << 12)	/* Max latency 5 cycles */
+# define MCI_CMDR_MAXLAT_64CYC	(  1 << 12)	/* Max latency 64 cycles */
+# define MCI_CMDR_START_XFER	(  1 << 16)	/* Start data transfer */
+# define MCI_CMDR_STOP_XFER	(  2 << 16)	/* Stop data transfer */
+# define MCI_CMDR_TRDIR_WRITE	(  0 << 18)	/* Write data */
+# define MCI_CMDR_TRDIR_READ	(  1 << 18)	/* Read data */
+# define MCI_CMDR_BLOCK		(  0 << 19)	/* Single-block transfer */
+# define MCI_CMDR_MULTI_BLOCK	(  1 << 19)	/* Multi-block transfer */
+# define MCI_CMDR_STREAM	(  2 << 19)	/* MMC Stream transfer */
+# define MCI_CMDR_SDIO_BYTE	(  4 << 19)	/* SDIO Byte transfer */
+# define MCI_CMDR_SDIO_BLOCK	(  5 << 19)	/* SDIO Block transfer */
+# define MCI_CMDR_SDIO_SUSPEND	(  1 << 24)	/* SDIO Suspend Command */
+# define MCI_CMDR_SDIO_RESUME	(  2 << 24)	/* SDIO Resume Command */
+#define MCI_BLKR		0x0018	/* Block */
+# define MCI_BCNT(x)		((x) <<  0)	/* Data Block Count */
+# define MCI_BLKLEN(x)		((x) << 16)	/* Data Block Length */
+#define MCI_RSPR		0x0020	/* Response 0 */
+#define MCI_RSPR1		0x0024	/* Response 1 */
+#define MCI_RSPR2		0x0028	/* Response 2 */
+#define MCI_RSPR3		0x002c	/* Response 3 */
+#define MCI_RDR			0x0030	/* Receive Data */
+#define MCI_TDR			0x0034	/* Transmit Data */
+#define MCI_SR			0x0040	/* Status */
+#define MCI_IER			0x0044	/* Interrupt Enable */
+#define MCI_IDR			0x0048	/* Interrupt Disable */
+#define MCI_IMR			0x004c	/* Interrupt Mask */
+# define MCI_CMDRDY		(  1 <<   0)	/* Command Ready */
+# define MCI_RXRDY		(  1 <<   1)	/* Receiver Ready */
+# define MCI_TXRDY		(  1 <<   2)	/* Transmitter Ready */
+# define MCI_BLKE		(  1 <<   3)	/* Data Block Ended */
+# define MCI_DTIP		(  1 <<   4)	/* Data Transfer In Progress */
+# define MCI_NOTBUSY		(  1 <<   5)	/* Data Not Busy */
+# define MCI_SDIOIRQA		(  1 <<   8)	/* SDIO IRQ in slot A */
+# define MCI_SDIOIRQB		(  1 <<   9)	/* SDIO IRQ in slot B */
+# define MCI_RINDE		(  1 <<  16)	/* Response Index Error */
+# define MCI_RDIRE		(  1 <<  17)	/* Response Direction Error */
+# define MCI_RCRCE		(  1 <<  18)	/* Response CRC Error */
+# define MCI_RENDE		(  1 <<  19)	/* Response End Bit Error */
+# define MCI_RTOE		(  1 <<  20)	/* Response Time-Out Error */
+# define MCI_DCRCE		(  1 <<  21)	/* Data CRC Error */
+# define MCI_DTOE		(  1 <<  22)	/* Data Time-Out Error */
+# define MCI_OVRE		(  1 <<  30)	/* RX Overrun Error */
+# define MCI_UNRE		(  1 <<  31)	/* TX Underrun Error */
+
+/* Register access macros */
+#define mci_readl(port,reg)				\
+	__raw_readl((port)->regs + MCI_##reg)
+#define mci_writel(port,reg,value)			\
+	__raw_writel((value), (port)->regs + MCI_##reg)
+
+#endif /* __DRIVERS_MMC_ATMEL_MCI_H__ */