Subject: [PATCH 08/13 v3] ARM: OMAP3: Add NAND support

From: Dirk Behme <[EMAIL PROTECTED]>

Add NAND support

Signed-off-by: Dirk Behme <[EMAIL PROTECTED]>

---

Changes in version v3:

- Fix/update NAND driver and seperate it into an own patch as proposed by Scott 
Wood

 drivers/mtd/nand/Makefile |    1 
 drivers/mtd/nand/omap3.c  |  380 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 381 insertions(+)

Index: u-boot-arm/drivers/mtd/nand/Makefile
===================================================================
--- u-boot-arm.orig/drivers/mtd/nand/Makefile
+++ u-boot-arm/drivers/mtd/nand/Makefile
@@ -38,6 +38,7 @@ endif
 COBJS-$(CONFIG_NAND_FSL_ELBC) += fsl_elbc_nand.o
 COBJS-$(CONFIG_NAND_FSL_UPM) += fsl_upm.o
 COBJS-$(CONFIG_NAND_S3C64XX) += s3c64xx.o
+COBJS-$(CONFIG_NAND_OMAP3) += omap3.o
 endif
 
 COBJS  := $(COBJS-y)
Index: u-boot-arm/drivers/mtd/nand/omap3.c
===================================================================
--- /dev/null
+++ u-boot-arm/drivers/mtd/nand/omap3.c
@@ -0,0 +1,380 @@
+/*
+ * (C) Copyright 2004-2008 Texas Instruments, <www.ti.com>
+ * Rohit Choraria <[EMAIL PROTECTED]>
+ *
+ * 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 <asm/io.h>
+#include <asm/arch/mem.h>
+#include <linux/mtd/nand_ecc.h>
+#include <nand.h>
+
+unsigned char cs;
+volatile unsigned long gpmc_cs_base_add;
+
+#define GPMC_BUF_EMPTY 0
+#define GPMC_BUF_FULL 1
+
+/*
+ * omap_nand_hwcontrol - Set the address pointers corretly for the
+ *                     following address/data/command operation
+ */
+static void omap_nand_hwcontrol(struct mtd_info *mtd, int cmd,
+                               unsigned int ctrl)
+{
+       register struct nand_chip *this = mtd->priv;
+
+       /* Point the IO_ADDR to DATA and ADDRESS registers instead
+          of chip address */
+       switch (ctrl) {
+       case NAND_CTRL_CHANGE | NAND_CTRL_CLE:
+               this->IO_ADDR_W = (void *) gpmc_cs_base_add + GPMC_NAND_CMD;
+               this->IO_ADDR_R = (void *) gpmc_cs_base_add + GPMC_NAND_DAT;
+               break;
+       case NAND_CTRL_CHANGE | NAND_CTRL_ALE:
+               this->IO_ADDR_W = (void *) gpmc_cs_base_add + GPMC_NAND_ADR;
+               this->IO_ADDR_R = (void *) gpmc_cs_base_add + GPMC_NAND_DAT;
+               break;
+       case NAND_CTRL_CHANGE | NAND_NCE:
+               this->IO_ADDR_W = (void *) gpmc_cs_base_add + GPMC_NAND_DAT;
+               this->IO_ADDR_R = (void *) gpmc_cs_base_add + GPMC_NAND_DAT;
+               break;
+       }
+
+       if (cmd != NAND_CMD_NONE)
+               writeb(cmd, this->IO_ADDR_W);
+}
+
+/*
+ * omap_nand_wait - called primarily after a program/erase operation
+ *                     so that we access NAND again only after the device
+ *                     is ready again.
+ * @mtd:        MTD device structure
+ * @chip:      nand_chip structure
+ */
+static int omap_nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
+{
+       register struct nand_chip *this = mtd->priv;
+       int status = 0;
+
+       this->IO_ADDR_W = (void *) gpmc_cs_base_add + GPMC_NAND_CMD;
+       this->IO_ADDR_R = (void *) gpmc_cs_base_add + GPMC_NAND_DAT;
+       /* Send the status command and loop until the device is free */
+       while (!(status & 0x40)) {
+               writeb(NAND_CMD_STATUS & 0xFF, this->IO_ADDR_W);
+               status = readb(this->IO_ADDR_R);
+       }
+       return status;
+}
+
+/*
+ * omap_nand_write_buf16 - [DEFAULT] write buffer to chip
+ * @mtd:       MTD device structure
+ * @buf:       data buffer
+ * @len:       number of bytes to write
+ *
+ * Default write function for 16bit buswith
+ */
+static void omap_nand_write_buf16(struct mtd_info *mtd, const u_char *buf,
+                               int len)
+{
+       int i;
+       struct nand_chip *this = mtd->priv;
+       u16 *p = (u16 *) buf;
+       len >>= 1;
+
+       for (i = 0; i < len; i++) {
+               writew(p[i], this->IO_ADDR_W);
+               while (GPMC_BUF_EMPTY == (readl(GPMC_STATUS) & GPMC_BUF_FULL));
+       }
+}
+
+/*
+ * omap_hwecc_init - Initialize the Hardware ECC for NAND flash in
+ *                   GPMC controller
+ * @mtd:        MTD device structure
+ *
+ */
+static void omap_hwecc_init(struct nand_chip *chip)
+{
+       unsigned long val = 0x0;
+
+       /* Init ECC Control Register */
+       /* Clear all ECC  | Enable Reg1 */
+       val = ((0x00000001 << 8) | 0x00000001);
+       writel(val, GPMC_BASE + GPMC_ECC_CONTROL);
+       writel(0x3fcff000, GPMC_BASE + GPMC_ECC_SIZE_CONFIG);
+}
+
+/*
+ * gen_true_ecc - This function will generate true ECC value, which
+ * can be used when correcting data read from NAND flash memory core
+ *
+ * @ecc_buf:   buffer to store ecc code
+ *
+ * @return:    re-formatted ECC value
+ */
+static unsigned int gen_true_ecc(u8 *ecc_buf)
+{
+       return ecc_buf[0] | (ecc_buf[1] << 16) | ((ecc_buf[2] & 0xF0) << 20) |
+           ((ecc_buf[2] & 0x0F) << 8);
+}
+
+/*
+ * omap_correct_data - Compares the ecc read from nand spare area with ECC
+ * registers values and corrects one bit error if it has occured
+ * Further details can be had from OMAP TRM and the following selected links:
+ * http://en.wikipedia.org/wiki/Hamming_code
+ * 
http://www.cs.utexas.edu/users/plaxton/c/337/05f/slides/ErrorCorrection-4.pdf
+ *
+ * @mtd:                MTD device structure
+ * @dat:                page data
+ * @read_ecc:           ecc read from nand flash
+ * @calc_ecc:           ecc read from ECC registers
+ *
+  * @return 0 if data is OK or corrected, else returns -1
+ */
+static int omap_correct_data(struct mtd_info *mtd, u_char *dat,
+                            u_char *read_ecc, u_char *calc_ecc)
+{
+       unsigned int orig_ecc, new_ecc, res, hm;
+       unsigned short parity_bits, byte;
+       unsigned char bit;
+
+       /* Regenerate the orginal ECC */
+       orig_ecc = gen_true_ecc(read_ecc);
+       new_ecc = gen_true_ecc(calc_ecc);
+       /* Get the XOR of real ecc */
+       res = orig_ecc ^ new_ecc;
+       if (res) {
+               /* Get the hamming width */
+               hm = hweight32(res);
+               /* Single bit errors can be corrected! */
+               if (hm == 12) {
+                       /* Correctable data! */
+                       parity_bits = res >> 16;
+                       bit = (parity_bits & 0x7);
+                       byte = (parity_bits >> 3) & 0x1FF;
+                       /* Flip the bit to correct */
+                       dat[byte] ^= (0x1 << bit);
+               } else if (hm == 1) {
+                       printf("Error: Ecc is wrong\n");
+                       /* ECC itself is corrupted */
+                       return 2;
+               } else {
+                       printf("Error: Bad compare! failed\n");
+                       /* detected 2 bit error */
+                       return -1;
+               }
+       }
+       return 0;
+}
+
+/*
+ *  omap_calculate_ecc - Generate non-inverted ECC bytes.
+ *
+ *  Using noninverted ECC can be considered ugly since writing a blank
+ *  page ie. padding will clear the ECC bytes. This is no problem as
+ *  long nobody is trying to write data on the seemingly unused page.
+ *  Reading an erased page will produce an ECC mismatch between
+ *  generated and read ECC bytes that has to be dealt with separately.
+ *  E.g. if page is 0xFF (fresh erased), and if HW ECC engine within GPMC
+ *  is used, the result of read will be 0x0 while the ECC offsets of the
+ *  spare area will be 0xFF which will result in an ECC mismatch.
+ *  @mtd:      MTD structure
+ *  @dat:      unused
+ *  @ecc_code: ecc_code buffer
+ */
+static int omap_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
+                             u_char *ecc_code)
+{
+       unsigned long val = 0x0;
+       unsigned long reg;
+
+       /* Start Reading from HW ECC1_Result = 0x200 */
+       reg = (unsigned long) (GPMC_BASE + GPMC_ECC1_RESULT);
+       val = readl(reg);
+
+       ecc_code[0] = val & 0xFF;
+       ecc_code[1] = (val >> 16) & 0xFF;
+       ecc_code[2] = ((val >> 8) & 0x0F) | ((val >> 20) & 0xF0);
+
+       /* Stop reading anymore ECC vals and clear old results
+        * enable will be called if more reads are required */
+       reg = (unsigned long) (GPMC_BASE + GPMC_ECC_CONFIG);
+       writel(0x000, reg);
+
+       return 0;
+}
+
+/*
+ * omap_enable_ecc - This function enables the hardware ecc functionality
+ * @mtd:        MTD device structure
+ * @mode:       Read/Write mode
+ */
+static void omap_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+       struct nand_chip *chip = mtd->priv;
+       unsigned int val, dev_width = (chip->options & NAND_BUSWIDTH_16) >> 1;
+
+       switch (mode) {
+       case NAND_ECC_READ:
+       case NAND_ECC_WRITE:
+               /* Clear the ecc result registers
+                * select ecc reg as 1
+                */
+               writel(0x101, GPMC_BASE +  GPMC_ECC_CONTROL);
+               /* Size 0 = 0xFF, Size1 is 0xFF - both are 512 bytes
+                * tell all regs to generate size0 sized regs
+                * we just have a single ECC engine for all CS
+                */
+               writel(0x3FCFF000, GPMC_BASE + GPMC_ECC_SIZE_CONFIG);
+               val = (dev_width << 7) | (cs << 1) | (0x1);
+               writel(val, GPMC_BASE + GPMC_ECC_CONFIG);
+               break;
+       default:
+               printf("Error: Unrecognized Mode[%d]!\n", mode);
+               break;
+       }
+}
+
+static struct nand_ecclayout hw_nand_oob_64 = {
+       .eccbytes = 12,
+       .eccpos = {
+                  2, 3, 4, 5,
+                  6, 7, 8, 9,
+                  10, 11, 12, 13},
+       .oobfree = { {14, 50} }
+};
+
+static struct nand_ecclayout sw_nand_oob_64 = {
+       .eccbytes = 24,
+       .eccpos = {
+                  40, 41, 42, 43, 44, 45, 46, 47,
+                  48, 49, 50, 51, 52, 53, 54, 55,
+                  56, 57, 58, 59, 60, 61, 62, 63},
+       .oobfree = { {2, 38} }
+};
+
+void omap_nand_switch_ecc(int hardware)
+{
+       struct nand_chip *nand;
+
+       if (nand_curr_device < 0 ||
+           nand_curr_device >= CONFIG_SYS_MAX_NAND_DEVICE ||
+           !nand_info[nand_curr_device].name) {
+               printf("Error: Can't switch ecc, no devices available\n");
+               return;
+       }
+
+       nand = (&nand_info[nand_curr_device])->priv;
+
+       if (!hardware) {
+               nand->ecc.mode = NAND_ECC_SOFT;
+               nand->ecc.layout = &sw_nand_oob_64;
+               nand->ecc.size = 256;   /* set default eccsize */
+               nand->ecc.bytes = 3;
+               nand->ecc.steps = 8;
+               nand->ecc.hwctl = 0;
+               nand->ecc.calculate = nand_calculate_ecc;
+               nand->ecc.correct = nand_correct_data;
+       } else {
+               nand->ecc.mode = NAND_ECC_HW;
+               nand->ecc.layout = &hw_nand_oob_64;
+               nand->ecc.size = 512;
+               nand->ecc.bytes = 3;
+               nand->ecc.steps = 4;
+               nand->ecc.hwctl = omap_enable_hwecc;
+               nand->ecc.correct = omap_correct_data;
+               nand->ecc.calculate = omap_calculate_ecc;
+               omap_hwecc_init(nand);
+       }
+}
+
+/*
+ * Board-specific NAND initialization. The following members of the
+ * argument are board-specific:
+ * - IO_ADDR_R: address to read the 8 I/O lines of the flash device
+ * - IO_ADDR_W: address to write the 8 I/O lines of the flash device
+ * - cmd_ctrl: hardwarespecific function for accesing control-lines
+ * - waitfunc: hardwarespecific function for accesing device ready/busy line
+ * - ecc.hwctl: function to enable (reset) hardware ecc generator
+ * - ecc.mode: mode of ecc, see defines
+ * - chip_delay: chip dependent delay for transfering data from array to
+ *   read regs (tR)
+ * - options: various chip options. They can partly be set to inform
+ *   nand_scan about special functionality. See the defines for further
+ *   explanation
+ */
+int board_nand_init(struct nand_chip *nand)
+{
+       int gpmc_config = 0;
+       cs = 0;
+       while (cs <= GPMC_MAX_CS) {
+               /* Each GPMC set for a single CS is at offset 0x30 */
+               /* already remapped for us */
+               gpmc_cs_base_add = (GPMC_CONFIG_CS0 + (cs * 0x30));
+               /* xloader/Uboot would have written the NAND type for us
+                * NOTE: This is a temporary measure and cannot handle ONENAND.
+                * The proper way of doing this is to pass the setup of
+                * u-boot up to kernel using kernel params - something on
+                * the lines of machineID
+                */
+               /* Check if NAND type is set */
+               if ((readl(gpmc_cs_base_add + GPMC_CONFIG1) & 0xC00) ==
+                   0x800) {
+                       /* Found it!! */
+                       break;
+               }
+               cs++;
+       }
+       if (cs > GPMC_MAX_CS) {
+               printf("NAND: Unable to find NAND settings in " \
+                      "GPMC Configuration - quitting\n");
+       }
+
+       gpmc_config = readl(GPMC_CONFIG);
+       /* Disable Write protect */
+       gpmc_config |= 0x10;
+       writel(gpmc_config, GPMC_CONFIG);
+
+       nand->IO_ADDR_R = (int *) gpmc_cs_base_add + GPMC_NAND_DAT;
+       nand->IO_ADDR_W = (int *) gpmc_cs_base_add + GPMC_NAND_CMD;
+
+       nand->cmd_ctrl = omap_nand_hwcontrol;
+       nand->options = NAND_NO_PADDING | NAND_CACHEPRG | NAND_NO_AUTOINCR |
+                       NAND_BUSWIDTH_16 | NAND_NO_AUTOINCR;
+
+       /* Use custom write buf due to additional delay. Read uses default. */
+       nand->write_buf = omap_nand_write_buf16;
+       nand->ecc.mode = NAND_ECC_SOFT;
+       /* if RDY/BSY line is connected to OMAP then use the omap ready
+        * function and the generic nand_wait function which reads the
+        * status register after monitoring the RDY/BSY line. Otherwise
+        * use a standard chip delay which is slightly more than tR
+        * (AC Timing) of the NAND device and read the status register
+        * until you get a failure or success
+        */
+       nand->waitfunc = omap_nand_wait;
+       nand->chip_delay = 50;
+
+       return 0;
+}
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