[PATCH 5/6] nand: driver for Nomadik 8815 SoC

[Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>]

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Andrea GALLO <andrea.gallo@stericsson.com>
Cc: Gael SALLES <gael.salles@stericsson.com>
---
 arch/arm/mach-nomadik/include/mach/nand.h |   16 ++
 drivers/mtd/nand/Kconfig                  |    5 +
 drivers/mtd/nand/Makefile                 |    1 +
 drivers/mtd/nand/nomadik_nand.c           |  248 +++++++++++++++++++++++++++++
 4 files changed, 270 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/mach-nomadik/include/mach/nand.h
 create mode 100644 drivers/mtd/nand/nomadik_nand.c

diff --git a/arch/arm/mach-nomadik/include/mach/nand.h b/arch/arm/mach-nomadik/include/mach/nand.h
new file mode 100644
index 0000000..265fe53
--- /dev/null
+++ b/arch/arm/mach-nomadik/include/mach/nand.h
@@ -0,0 +1,16 @@
+#ifndef __ASM_ARCH_NAND_H
+#define __ASM_ARCH_NAND_H
+
+struct nomadik_nand_platform_data {
+	unsigned long data_va;
+	unsigned long cmd_va;
+	unsigned long addr_va;
+	int options;
+	int (*init) (void);
+};
+
+#define NAND_IO_DATA	0x40000000
+#define NAND_IO_CMD	0x40800000
+#define NAND_IO_ADDR	0x41000000
+
+#endif				/* __ASM_ARCH_NAND_H */
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index ddc0c34..475499a 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -97,5 +97,10 @@ config MTD_NAND_DISKONCHIP_BBTWRITE
 	  load time (assuming you build diskonchip as a module) with the module
 	  parameter "inftl_bbt_write=1".
 
+config MTD_NAND_NOMADIK
+	tristate "ST Nomadik 8815 NAND support"
+	depends on ARCH_NOMADIK
+	help
+	  Driver for the NAND flash controller on the Nomadik, with ECC.
 
 endif
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 73f7346..bac39e7 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -5,6 +5,7 @@ obj-$(CONFIG_MTD_NAND_IDS)		+= nand_ids.o
 obj-$(CONFIG_NAND)			+= nand_base.o nand_bbt.o
 
 obj-$(CONFIG_MTD_NAND_DISKONCHIP)	+= diskonchip.o
+obj-$(CONFIG_MTD_NAND_NOMADIK)		+= nomadik_nand.o
 obj-$(CONFIG_NAND_IMX)			+= nand_imx.o
 obj-$(CONFIG_NAND_OMAP_GPMC)		+= nand_omap_gpmc.o
 obj-$(CONFIG_NAND_ATMEL)		+= atmel_nand.o
diff --git a/drivers/mtd/nand/nomadik_nand.c b/drivers/mtd/nand/nomadik_nand.c
new file mode 100644
index 0000000..673fd88
--- /dev/null
+++ b/drivers/mtd/nand/nomadik_nand.c
@@ -0,0 +1,248 @@
+/*
+ *  drivers/mtd/nand/nomadik_nand.c
+ *
+ *  Overview:
+ *  	Driver for on-board NAND flash on Nomadik Platforms
+ *
+ * Copyright (C) 2007 STMicroelectronics Pvt. Ltd.
+ * Author: Sachin Verma <sachin.verma@st.com>
+ *
+ * Copyright (C) 2009 Alessandro Rubini
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <common.h>
+#include <driver.h>
+#include <malloc.h>
+#include <init.h>
+
+#include <linux/types.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+
+#include <asm/io.h>
+#include <mach/nand.h>
+#include <mach/fsmc.h>
+
+#include <errno.h>
+
+struct nomadik_nand_host {
+	struct mtd_info		mtd;
+	struct nand_chip	nand;
+	void __iomem *cmd_va;
+	void __iomem *addr_va;
+	struct nand_bbt_descr *bbt_desc;
+};
+
+static inline int parity(int b) /* uses low 8 bits: returns 0 or all-1 */
+{
+	b = b ^ (b >> 4);
+	b = b ^ (b >> 2);
+	return (b ^ (b >> 1)) & 1
+		? ~0 : 0;
+}
+
+/*
+ * This is the ECC routine used in hardware, according to the manual.
+ * HW claims to make the calculation but not the correction. However,
+ * I haven't managed to get the desired data out of it; so do it in sw.
+ * There is problably some errata involved, but currently miss the info.
+ */
+static int nomadik_ecc512_calc(struct mtd_info *mtd, const u_char *data,
+			u_char *ecc)
+{
+	int gpar = 0;
+	int i, val, par;
+	int pbits = 0;		/* P8, P16, ... P2048 */
+	int pprime = 0;		/* P8', P16', ... P2048' */
+	int lowbits;		/* P1, P2, P4 and primes */
+
+	for (i = 0; i < 512; i++) {
+		par = parity((val = data[i]));
+		gpar ^= val;
+		pbits ^= (i & par);
+	}
+	/*
+	 * Ok, now gpar is global parity (xor of all bytes)
+	 * pbits are all the parity bits (non-prime ones)
+	 */
+	par = parity(gpar);
+	pprime = pbits ^ par;
+	/* Put low bits in the right position for ecc[2] (bits 7..2) */
+	lowbits = 0
+		| (parity(gpar & 0xf0) & 0x80)	/* P4  */
+		| (parity(gpar & 0x0f) & 0x40)	/* P4' */
+		| (parity(gpar & 0xcc) & 0x20)	/* P2  */
+		| (parity(gpar & 0x33) & 0x10)	/* P2' */
+		| (parity(gpar & 0xaa) & 0x08)	/* P1  */
+		| (parity(gpar & 0x55) & 0x04);	/* P1' */
+
+	ecc[2] = ~(lowbits | ((pbits & 0x100) >> 7) | ((pprime & 0x100) >> 8));
+	/* now intermix bits for ecc[1] (P1024..P128') and ecc[0] (P64..P8') */
+	ecc[1] = ~(    (pbits & 0x80) >> 0  | ((pprime & 0x80) >> 1)
+		    | ((pbits & 0x40) >> 1) | ((pprime & 0x40) >> 2)
+		    | ((pbits & 0x20) >> 2) | ((pprime & 0x20) >> 3)
+		    | ((pbits & 0x10) >> 3) | ((pprime & 0x10) >> 4));
+
+	ecc[0] = ~(    (pbits & 0x8) << 4  | ((pprime & 0x8) << 3)
+		    | ((pbits & 0x4) << 3) | ((pprime & 0x4) << 2)
+		    | ((pbits & 0x2) << 2) | ((pprime & 0x2) << 1)
+		    | ((pbits & 0x1) << 1) | ((pprime & 0x1) << 0));
+	return 0;
+}
+
+static int nomadik_ecc512_correct(struct mtd_info *mtd, uint8_t *dat,
+				uint8_t *r_ecc, uint8_t *c_ecc)
+{
+	struct nand_chip *chip = mtd->priv;
+	uint32_t r, c, d, diff; /*read, calculated, xor of them */
+
+	if (!memcmp(r_ecc, c_ecc, chip->ecc.bytes))
+		return 0;
+
+	/* Reorder the bytes into ascending-order 24 bits -- see manual */
+	r = r_ecc[2] << 22 | r_ecc[1] << 14 | r_ecc[0] << 6 | r_ecc[2] >> 2;
+	c = c_ecc[2] << 22 | c_ecc[1] << 14 | c_ecc[0] << 6 | c_ecc[2] >> 2;
+	diff = (r ^ c) & ((1 << 24) - 1); /* use 24 bits only */
+
+	/* If 12 bits are different, one per pair, it's correctable */
+	if (((diff | (diff>>1)) & 0x555555) == 0x555555) {
+		int bit = ((diff & 2) >> 1)
+			| ((diff & 0x8) >> 2) | ((diff & 0x20) >> 3);
+		int byte;
+
+		d = diff >> 6; /* remove bit-order info */
+		byte =  ((d & 2) >> 1)
+			| ((d & 0x8) >> 2) | ((d & 0x20) >> 3)
+			| ((d & 0x80) >> 4) | ((d & 0x200) >> 5)
+			| ((d & 0x800) >> 6) | ((d & 0x2000) >> 7)
+			| ((d & 0x8000) >> 8) | ((d & 0x20000) >> 9);
+		/* correct the single bit */
+		dat[byte] ^= 1 << bit;
+		return 0;
+	}
+	/* If 1 bit only differs, it's one bit error in ECC, ignore */
+	if ((diff ^ (1 << (ffs(diff) - 1))) == 0)
+		return 0;
+	/* Otherwise, uncorrectable */
+	return -1;
+}
+
+static struct nand_ecclayout nomadik_ecc_layout = {
+	.eccbytes = 3 * 4,
+	.eccpos = { /* each subpage has 16 bytes: pos 2,3,4 hosts ECC */
+		0x02, 0x03, 0x04,
+		0x12, 0x13, 0x14,
+		0x22, 0x23, 0x24,
+		0x32, 0x33, 0x34},
+	/* let's keep bytes 5,6,7 for us, just in case we change ECC algo */
+	.oobfree = { {0x08, 0x08}, {0x18, 0x08}, {0x28, 0x08}, {0x38, 0x08} },
+};
+
+static void nomadik_ecc_control(struct mtd_info *mtd, int mode)
+{
+	/* No need to enable hw ecc, it's on by default */
+}
+
+static void nomadik_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
+{
+	struct nand_chip *nand = mtd->priv;
+	struct nomadik_nand_host *host = nand->priv;
+
+	if (cmd == NAND_CMD_NONE)
+		return;
+
+	if (ctrl & NAND_CLE)
+		writeb(cmd, host->cmd_va);
+	else
+		writeb(cmd, host->addr_va);
+}
+
+static int nomadik_nand_probe(struct device_d *dev)
+{
+	struct nomadik_nand_platform_data *pdata = dev->platform_data;
+	struct nomadik_nand_host *host;
+	struct mtd_info *mtd;
+	struct nand_chip *nand;
+	int ret = 0;
+
+	/* Allocate memory for the device structure (and zero it) */
+	host = kzalloc(sizeof(struct nomadik_nand_host), GFP_KERNEL);
+	if (!host) {
+		dev_err(dev, "Failed to allocate device structure.\n");
+		return -ENOMEM;
+	}
+
+	/* Call the client's init function, if any */
+	if (pdata->init && (ret = pdata->init()) < 0) {
+		dev_err(dev, "Init function failed\n");
+		goto err;
+	}
+
+	host->cmd_va = (void __iomem*)pdata->cmd_va;
+	host->addr_va = (void __iomem*)pdata->addr_va;
+
+	/* Link all private pointers */
+	mtd = &host->mtd;
+	nand = &host->nand;
+	mtd->priv = nand;
+	nand->priv = host;
+
+	nand->IO_ADDR_R = (void __iomem*)pdata->data_va;
+	nand->IO_ADDR_W = (void __iomem*)pdata->data_va;
+	nand->cmd_ctrl = nomadik_cmd_ctrl;
+
+	nand->ecc.mode = NAND_ECC_HW;
+	nand->ecc.layout = &nomadik_ecc_layout;
+	nand->ecc.calculate = nomadik_ecc512_calc;
+	nand->ecc.correct = nomadik_ecc512_correct;
+	nand->ecc.hwctl = nomadik_ecc_control;
+	nand->ecc.size = 512;
+	nand->ecc.bytes = 3;
+
+	nand->options = pdata->options;
+
+	/*
+	 * Scan to find existance of the device
+	 */
+	if (nand_scan(&host->mtd, 1)) {
+		ret = -ENXIO;
+		goto err;
+	}
+
+	pr_info("Registering %s as whole device\n", mtd->name);
+	add_mtd_device(mtd);
+
+	return 0;
+
+err:
+	kfree(host);
+	return ret;
+}
+
+static struct driver_d nomadik_nand_driver = {
+	.probe = nomadik_nand_probe,
+	.name = "nomadik_nand",
+};
+
+static int __init nand_nomadik_init(void)
+{
+	pr_info("Nomadik NAND driver\n");
+	return register_driver(&nomadik_nand_driver);
+}
+
+device_initcall(nand_nomadik_init);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("ST Microelectronics (sachin.verma@st.com)");
+MODULE_DESCRIPTION("NAND driver for Nomadik Platform");
-- 
1.7.1


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox