SPEAr : nand driver support for SPEAr SoCs

SPEAr SoCs contain an FSMC controller which can be used to interface
with a range of memories eg. NAND, SRAM, NOR.
Currently, this driver supports interfacing FSMC with NAND memories

Signed-off-by: Vipin <vipin.kumar@st.com>
diff --git a/drivers/mtd/nand/spr_nand.c b/drivers/mtd/nand/spr_nand.c
new file mode 100755
index 0000000..097d0c6
--- /dev/null
+++ b/drivers/mtd/nand/spr_nand.c
@@ -0,0 +1,124 @@
+/*
+ * (C) Copyright 2009
+ * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <nand.h>
+#include <linux/mtd/nand_ecc.h>
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/spr_nand.h>
+
+static struct fsmc_regs *const fsmc_regs_p =
+    (struct fsmc_regs *)CONFIG_SPEAR_FSMCBASE;
+
+static struct nand_ecclayout spear_nand_ecclayout = {
+	.eccbytes = 24,
+	.eccpos = {2, 3, 4, 18, 19, 20, 34, 35, 36, 50, 51, 52,
+		   66, 67, 68, 82, 83, 84, 98, 99, 100, 114, 115, 116},
+	.oobfree = {
+		    {.offset = 8, .length = 8},
+		    {.offset = 24, .length = 8},
+		    {.offset = 40, .length = 8},
+		    {.offset = 56, .length = 8},
+		    {.offset = 72, .length = 8},
+		    {.offset = 88, .length = 8},
+		    {.offset = 104, .length = 8},
+		    {.offset = 120, .length = 8}
+		    }
+};
+
+static void spear_nand_hwcontrol(struct mtd_info *mtd, int cmd, uint ctrl)
+{
+	struct nand_chip *this = mtd->priv;
+	ulong IO_ADDR_W;
+
+	if (ctrl & NAND_CTRL_CHANGE) {
+		IO_ADDR_W = (ulong)this->IO_ADDR_W;
+
+		IO_ADDR_W &= ~(CONFIG_SYS_NAND_CLE | CONFIG_SYS_NAND_ALE);
+		if (ctrl & NAND_CLE)
+			IO_ADDR_W |= CONFIG_SYS_NAND_CLE;
+		if (ctrl & NAND_ALE)
+			IO_ADDR_W |= CONFIG_SYS_NAND_ALE;
+
+		if (ctrl & NAND_NCE) {
+			writel(readl(&fsmc_regs_p->genmemctrl_pc) |
+			       FSMC_ENABLE, &fsmc_regs_p->genmemctrl_pc);
+		} else {
+			writel(readl(&fsmc_regs_p->genmemctrl_pc) &
+			       ~FSMC_ENABLE, &fsmc_regs_p->genmemctrl_pc);
+		}
+		this->IO_ADDR_W = (void *)IO_ADDR_W;
+	}
+
+	if (cmd != NAND_CMD_NONE)
+		writeb(cmd, this->IO_ADDR_W);
+}
+
+static int spear_read_hwecc(struct mtd_info *mtd,
+			    const u_char *data, u_char ecc[3])
+{
+	u_int ecc_tmp;
+
+	/* read the h/w ECC */
+	ecc_tmp = readl(&fsmc_regs_p->genmemctrl_ecc);
+
+	ecc[0] = (u_char) (ecc_tmp & 0xFF);
+	ecc[1] = (u_char) ((ecc_tmp & 0xFF00) >> 8);
+	ecc[2] = (u_char) ((ecc_tmp & 0xFF0000) >> 16);
+
+	return 0;
+}
+
+void spear_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+	writel(readl(&fsmc_regs_p->genmemctrl_pc) & ~0x80,
+	       &fsmc_regs_p->genmemctrl_pc);
+	writel(readl(&fsmc_regs_p->genmemctrl_pc) & ~FSMC_ECCEN,
+	       &fsmc_regs_p->genmemctrl_pc);
+	writel(readl(&fsmc_regs_p->genmemctrl_pc) | FSMC_ECCEN,
+	       &fsmc_regs_p->genmemctrl_pc);
+}
+
+int spear_nand_init(struct nand_chip *nand)
+{
+	writel(FSMC_DEVWID_8 | FSMC_DEVTYPE_NAND | FSMC_ENABLE | FSMC_WAITON,
+	       &fsmc_regs_p->genmemctrl_pc);
+	writel(readl(&fsmc_regs_p->genmemctrl_pc) | FSMC_TCLR_1 | FSMC_TAR_1,
+	       &fsmc_regs_p->genmemctrl_pc);
+	writel(FSMC_THIZ_1 | FSMC_THOLD_4 | FSMC_TWAIT_6 | FSMC_TSET_0,
+	       &fsmc_regs_p->genmemctrl_comm);
+	writel(FSMC_THIZ_1 | FSMC_THOLD_4 | FSMC_TWAIT_6 | FSMC_TSET_0,
+	       &fsmc_regs_p->genmemctrl_attrib);
+
+	nand->options = 0;
+	nand->ecc.mode = NAND_ECC_HW;
+	nand->ecc.layout = &spear_nand_ecclayout;
+	nand->ecc.size = 512;
+	nand->ecc.bytes = 3;
+	nand->ecc.calculate = spear_read_hwecc;
+	nand->ecc.hwctl = spear_enable_hwecc;
+	nand->ecc.correct = nand_correct_data;
+	nand->cmd_ctrl = spear_nand_hwcontrol;
+	return 0;
+}