Re: [PATCH] CM-x2xx NAND flash support

[Mike Rapoport <mike@compulab.co.il>]

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Thomas Gleixner wrote:

>On Thu, 2006-07-06 at 14:48 +0200, Mike Rapoport wrote:
>  
>
>>This patch provides MTD support for NAND flash devices on CM-x2xx modules.
>>
>>Signed-off-by: Mike Rapoport <mike@compulab.co.il>
>>    
>>
I've tried to fix all the coding style errors.

>  
>
>>+#define DRAIN_WB() \
>>+       do { \
>>+               unsigned char dummy; \
>>+               asm volatile ("mcr p15, 0, r0, c7, c10, 4":::"r0"); \
>>+               dummy=*((unsigned char*)UNCACHED_ADDR); \
>>+       } while(0);
>>    
>>
>I bet xscale has this functionality somewhere as a macro / inline already
>
>  
>
There's dma_clean_range but it's not exactly what I need, so I left this 
macro (without the last semi column)

>>+       unsigned int nandaddr = (unsigned int)this->IO_ADDR_W;
>>    
>>
>
>what the hell is this type cast for ?
>
>	void __iomem *nandaddr = 
>
>  
>
>>+       unsigned int nandaddr = (unsigned int)this->IO_ADDR_W;
>>+
>>+       DRAIN_WB();
>>+
>>+       if ( ctrl & NAND_CTRL_CHANGE ) {
>>+               if ( ctrl & NAND_ALE ) /* ALE should be changed */
>>+                       nandaddr |=  (1 << 3);
>>+               else
>>+                       nandaddr &= ~(1 << 3);
>>+               if ( ctrl & NAND_CLE ) /* CLE should be changed */
>>+                       nandaddr |=  (1 << 2);
>>+               else 
>>+                       nandaddr &= ~(1 << 2);
>>+               if ( ctrl & NAND_NCE ) /* CE should be changed */
>>+                       nand_cs_on();
>>+               else
>>+                       nand_cs_off();
>>+       }
>>+       this->IO_ADDR_W = (void*)nandaddr;
>>    
>>
>	dito	
>
As I wrote earlier, void* cannot be operand of bitwise operations. I 
have ALE and CLE connected to local bus address lines, that's why I'm 
using bitwise operations for address. I'll appreciate any other way to 
achieve the same functionality, but I've found none.

>Can you please combine both drivers into one and make it a platform
>device. There is no need to keep lots of duplicate functionality around.
>  
>
Sorry for the inconvenience, but I've dropped x255 support, so I don't 
it makes sense to make the driver platform device.

>	tglx
>
>
>______________________________________________________
>Linux MTD discussion mailing list
>http://lists.infradead.org/mailman/listinfo/linux-mtd/
>
>  
>


-- 
Sincerely yours,
Mike Rapoport


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 drivers/mtd/nand/Kconfig       |    4 +
 drivers/mtd/nand/Makefile      |    1 
 drivers/mtd/nand/cmx270-nand.c |  271 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 276 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 3db77ee..4c212fd 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -232,6 +232,10 @@ config MTD_NAND_CS553X
 
 	  If you say "m", the module will be called "cs553x_nand.ko".
 
+config MTD_NAND_CM_X270
+	tristate "Support for NAND Flash on CM-X270 modules"
+	depends on MTD_NAND && MACH_CM_X270
+
 config MTD_NAND_NANDSIM
 	tristate "Support for NAND Flash Simulator"
 	depends on MTD_NAND && MTD_PARTITIONS
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index f747593..f2718aa 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -22,5 +22,6 @@ obj-$(CONFIG_MTD_NAND_TS7250)		+= ts7250
 obj-$(CONFIG_MTD_NAND_NANDSIM)		+= nandsim.o
 obj-$(CONFIG_MTD_NAND_CS553X)		+= cs553x_nand.o
 obj-$(CONFIG_MTD_NAND_NDFC)		+= ndfc.o
+obj-$(CONFIG_MTD_NAND_CM_X270)		+= cmx270-nand.o
 
 nand-objs = nand_base.o nand_bbt.o
diff --git a/drivers/mtd/nand/cmx270-nand.c b/drivers/mtd/nand/cmx270-nand.c
new file mode 100644
index 0000000..8a1911c
--- /dev/null
+++ b/drivers/mtd/nand/cmx270-nand.c
@@ -0,0 +1,271 @@
+/*
+ *  linux/drivers/mtd/nand/cmx270-nand.c
+ *
+ *  Copyright (C) 2006 Compulab, Ltd.
+ *  Mike Rapoport <mike@compulab.co.il>
+ *
+ *  Derived from drivers/mtd/nand/h1910.c
+ *       Copyright (C) 2002 Marius Gröger (mag@sysgo.de)
+ *       Copyright (c) 2001 Thomas Gleixner (gleixner@autronix.de)
+ *
+ *
+ * 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.
+ *
+ *  Overview:
+ *   This is a device driver for the NAND flash device found on the
+ *   CM-X270 board.
+ */
+
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+
+#include <asm/arch/hardware.h>
+#include <asm/arch/pxa-regs.h>
+
+#define GPIO_NAND_CS	(11)
+#define GPIO_NAND_RB	(89)
+
+/* This macro needed to ensure in-order operation of GPIO and local
+ * bus. Without both asm command and dummy uncached read there're
+ * states when NAND access is broken. I've looked for such macro(s) in
+ * include/asm-arm but found nothing approptiate.
+ * dmac_clean_range is close, but is makes cache invalidation
+ * unnecessary here and it cannot be used in module
+ */
+#define DRAIN_WB() \
+	do { \
+		unsigned char dummy; \
+		asm volatile ("mcr p15, 0, r0, c7, c10, 4":::"r0"); \
+		dummy=*((unsigned char*)UNCACHED_ADDR); \
+	} while(0)
+
+/* MTD structure for CM-X270 board */
+static struct mtd_info *cmx270_nand_mtd;
+
+/* remaped IO address of the device */
+static void __iomem *cmx270_nand_io;
+
+/*
+ * Define static partitions for flash device
+ */
+static struct mtd_partition partition_info[] = {
+	{
+		.name	= "cmx270-0",
+		.offset	= 0,
+		.size	= MTDPART_SIZ_FULL
+	}
+};
+#define NUM_PARTITIONS (ARRAY_SIZE(partition_info))
+
+const char *part_probes[] = { "cmdlinepart", NULL };
+
+static 	u_char cmx270_read_byte(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd->priv;
+
+	return (readl(this->IO_ADDR_R) >> 16);
+}
+
+static void cmx270_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
+{
+	int i;
+	struct nand_chip *this = mtd->priv;
+
+	for (i=0; i<len; i++)
+		writel((*buf++ << 16), this->IO_ADDR_W);
+}
+
+static void cmx270_read_buf(struct mtd_info *mtd, u_char *buf, int len)
+{
+	int i;
+	struct nand_chip *this = mtd->priv;
+
+	for (i=0; i<len; i++)
+		*buf++ = readl(this->IO_ADDR_R) >> 16;
+}
+
+static int cmx270_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
+{
+	int i;
+	struct nand_chip *this = mtd->priv;
+
+	for (i=0; i<len; i++)
+		if (buf[i] != (u_char)(readl(this->IO_ADDR_R) >> 16))
+			return -EFAULT;
+
+	return 0;
+}
+
+static inline void nand_cs_on(void)
+{
+	GPCR(GPIO_NAND_CS) = GPIO_bit(GPIO_NAND_CS);
+}
+
+static void nand_cs_off(void)
+{
+	DRAIN_WB();
+
+	GPSR(GPIO_NAND_CS) = GPIO_bit(GPIO_NAND_CS);
+}
+
+/*
+ *	hardware specific access to control-lines
+ */
+static void cmx270_hwcontrol(struct mtd_info *mtd, int dat,
+			     unsigned int ctrl)
+{
+	struct nand_chip* this = mtd->priv;
+	unsigned int nandaddr = (unsigned int)this->IO_ADDR_W;
+
+	DRAIN_WB();
+
+	if (ctrl & NAND_CTRL_CHANGE) {
+		if ( ctrl & NAND_ALE )
+			nandaddr |=  (1 << 3);
+		else
+			nandaddr &= ~(1 << 3);
+		if ( ctrl & NAND_CLE )
+			nandaddr |=  (1 << 2);
+		else
+			nandaddr &= ~(1 << 2);
+		if ( ctrl & NAND_NCE )
+			nand_cs_on();
+		else
+			nand_cs_off();
+	}
+
+	DRAIN_WB();
+	this->IO_ADDR_W = (void __iomem*)nandaddr;
+	if (dat != NAND_CMD_NONE)
+		writel((dat << 16), this->IO_ADDR_W);
+
+	DRAIN_WB();
+}
+
+/*
+ *	read device ready pin
+ */
+static int cmx270_device_ready(struct mtd_info *mtd)
+{
+	DRAIN_WB();
+
+	return (GPLR(GPIO_NAND_RB) & GPIO_bit(GPIO_NAND_RB));
+}
+
+/*
+ * Main initialization routine
+ */
+static int __devinit cmx270_init(void)
+{
+	struct nand_chip *this;
+	const char *part_type;
+	struct mtd_partition *mtd_parts;
+	int mtd_parts_nb = 0;
+	int ret;
+
+	/* Allocate memory for MTD device structure and private data */
+	cmx270_nand_mtd = kzalloc(sizeof(struct mtd_info) +
+				  sizeof(struct nand_chip),
+				  GFP_KERNEL);
+	if (!cmx270_nand_mtd) {
+		printk("Unable to allocate CM-X270 NAND MTD device structure.\n");
+		return -ENOMEM;
+	}
+
+	cmx270_nand_io = ioremap(PXA_CS1_PHYS, 12);
+	if (!cmx270_nand_io) {
+		printk("Unable to ioremap NAND device\n");
+		ret = -EINVAL;
+		goto err1;
+	}
+
+	/* Get pointer to private data */
+	this = (struct nand_chip *)(&cmx270_nand_mtd[1]);
+
+	/* Link the private data with the MTD structure */
+	cmx270_nand_mtd->owner = THIS_MODULE;
+	cmx270_nand_mtd->priv = this;
+
+	/* insert callbacks */
+	this->IO_ADDR_R = cmx270_nand_io;
+	this->IO_ADDR_W = cmx270_nand_io;
+	this->cmd_ctrl = cmx270_hwcontrol;
+	this->dev_ready = cmx270_device_ready;
+
+	/* 15 us command delay time */
+	this->chip_delay = 20;
+	this->ecc.mode = NAND_ECC_SOFT;
+
+	/* read/write functions */
+	this->read_byte = cmx270_read_byte;
+	this->read_buf = cmx270_read_buf;
+	this->write_buf = cmx270_write_buf;
+	this->verify_buf = cmx270_verify_buf;
+
+	/* Scan to find existence of the device */
+	if (nand_scan (cmx270_nand_mtd, 1)) {
+		printk(KERN_NOTICE "No NAND device\n");
+		ret = -ENXIO;
+		goto err2;
+	}
+
+#ifdef CONFIG_MTD_CMDLINE_PARTS
+	mtd_parts_nb = parse_mtd_partitions(cmx270_nand_mtd, part_probes,
+					    &mtd_parts, 0);
+	if (mtd_parts_nb > 0)
+		part_type = "command line";
+	else
+		mtd_parts_nb = 0;
+#endif
+	if (!mtd_parts_nb) {
+		mtd_parts = partition_info;
+		mtd_parts_nb = NUM_PARTITIONS;
+		part_type = "static";
+	}
+
+	/* Register the partitions */
+	printk(KERN_NOTICE "Using %s partition definition\n", part_type);
+	ret = add_mtd_partitions(cmx270_nand_mtd, mtd_parts, mtd_parts_nb);
+	if (ret)
+		goto err2;
+
+	/* Return happy */
+	return 0;
+
+err2:
+	iounmap(cmx270_nand_io);
+err1:
+	kfree(cmx270_nand_mtd);
+
+	return ret;
+
+}
+module_init(cmx270_init);
+
+/*
+ * Clean up routine
+ */
+static void __devexit cmx270_cleanup(void)
+{
+	/* Release resources, unregister device */
+	nand_release(cmx270_nand_mtd);
+
+	iounmap(cmx270_nand_io);
+
+	/* Free the MTD device structure */
+	kfree (cmx270_nand_mtd);
+}
+module_exit(cmx270_cleanup);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
+MODULE_DESCRIPTION("NAND flash driver for Compulab CM-X270 Module");