[PATCH 1/6] Unified AVR32/AT91 MCI Driver

Rob Emanuele
2009-06-13T01:02:43Z

Unification of the atmel-mci driver to support the AT91 processors MCI
interface. The atmel-mci driver currently supports the AVR32 and this
patch adds AT91 support.

To use this new driver on a at91 the platform driver for your board
needs to updated. See the following patch for an example of how to do
that.

Please read the whole set, try it out, and comment.

Thank you,

Rob Emanuele

---
drivers/mmc/host/Kconfig | 16 ++++++++++++----
drivers/mmc/host/atmel-mci.c | 33 +++++++++++++++++++++++++++++----
2 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index b4cf691..6e2f52b 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -124,6 +124,12 @@ config MMC_AU1X

If unsure, say N.

+choice
+ prompt "Atmel MMC Driver"
+ default MMC_ATMELMCI
+ help
+ Choose which driver to use for the Atmel MCI Silicon
+
config MMC_AT91
tristate "AT91 SD/MMC Card Interface support"
depends on ARCH_AT91
@@ -134,17 +140,19 @@ config MMC_AT91

config MMC_ATMELMCI
tristate "Atmel Multimedia Card Interface support"
- depends on AVR32
+ depends on AVR32 || ARCH_AT91
help
This selects the Atmel Multimedia Card Interface driver. If
- you have an AT32 (AVR32) platform with a Multimedia Card
- slot, say Y or M here.
+ you have an AT32 (AVR32) or AT91 platform with a Multimedia
+ Card slot, say Y or M here.

If unsure, say N.

+endchoice
+
config MMC_ATMELMCI_DMA
bool "Atmel MCI DMA support (EXPERIMENTAL)"
- depends on MMC_ATMELMCI && DMA_ENGINE && EXPERIMENTAL
+ depends on MMC_ATMELMCI && AVR32 && DMA_ENGINE && EXPERIMENTAL
help
Say Y here to have the Atmel MCI driver use a DMA engine to
do data transfers and thus increase the throughput and
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index cf6a100..497dd51 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -2,11 +2,13 @@
* Atmel MultiMedia Card Interface driver
*
* Copyright (C) 2004-2008 Atmel Corporation
+ * Copyright (C) 2009 Rob Emanuele
*
* 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/blkdev.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
@@ -30,11 +32,14 @@
#include <asm/io.h>
#include <asm/unaligned.h>

+#include <mach/cpu.h>
#include <mach/board.h>

#include "atmel-mci-regs.h"

-#define ATMCI_DATA_ERROR_FLAGS (MCI_DCRCE | MCI_DTOE | MCI_OVRE | MCI_UNRE)
+#define ATMCI_DATA_ERROR_FLAGS (MCI_RINDE | MCI_RDIRE | MCI_RCRCE \
+ | MCI_RENDE | MCI_RTOE | MCI_DCRCE \
+ | MCI_DTOE | MCI_OVRE | MCI_UNRE)
#define ATMCI_DMA_THRESHOLD 16

enum {
@@ -208,6 +213,18 @@ struct atmel_mci_slot {
set_bit(event, &host->pending_events)

/*
+ * Enable or disable features/registers based on
+ * whether the processor supports them
+ */
+static bool mci_has_rwproof(void)
+{
+ if (cpu_is_at91sam9261() || cpu_is_at91rm9200())
+ return false;
+ else
+ return true;
+}
+
+/*
* The debugfs stuff below is mostly optimized away when
* CONFIG_DEBUG_FS is not set.
*/
@@ -274,8 +291,12 @@ static void atmci_show_status_reg(struct seq_file *s,
[3] = "BLKE",
[4] = "DTIP",
[5] = "NOTBUSY",
+ [6] = "ENDRX",
+ [7] = "ENDTX",
[8] = "SDIOIRQA",
[9] = "SDIOIRQB",
+ [14] = "RXBUFF",
+ [15] = "TXBUFE",
[16] = "RINDE",
[17] = "RDIRE",
[18] = "RCRCE",
@@ -847,13 +868,15 @@ static void atmci_set_ios(struct mmc_host *mmc,
struct mmc_ios *ios)
clkdiv = 255;
}

+ host->mode_reg = MCI_MR_CLKDIV(clkdiv);
+
/*
* WRPROOF and RDPROOF prevent overruns/underruns by
* stopping the clock when the FIFO is full/empty.
* This state is not expected to last for long.
*/
- host->mode_reg = MCI_MR_CLKDIV(clkdiv) | MCI_MR_WRPROOF
- | MCI_MR_RDPROOF;
+ if (mci_has_rwproof())
+ host->mode_reg |= (MCI_MR_WRPROOF | MCI_MR_RDPROOF);

if (list_empty(&host->queue))
mci_writel(host, MR, host->mode_reg);
@@ -1642,8 +1665,10 @@ static int __init atmci_probe(struct
platform_device *pdev)
nr_slots++;
}

- if (!nr_slots)
+ if (!nr_slots) {
+ printk(KERN_ERR "Atmel MCI controller init failed. atmci_init_slot
error or no slots with bus_width > 0.\n");
goto err_init_slot;
+ }

dev_info(&pdev->dev,
"Atmel MCI controller at 0x%08lx irq %d, %u slots\n",