arch/arm/mach-omap2/gpmc-nand.c

   1 /*
   2  * gpmc-nand.c
   3  *
   4  * Copyright (C) 2009 Texas Instruments
   5  * Vimal Singh <vimalsingh@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/io.h>
  15 #include <linux/omap-gpmc.h>
  16 #include <linux/mtd/nand.h>
  17 #include <linux/platform_data/mtd-nand-omap2.h>
  18
  19 #include <asm/mach/flash.h>
  20
  21 #include "soc.h"
  22
  23 /* minimum size for IO mapping */
  24 #define NAND_IO_SIZE    4
  25
  26 static bool gpmc_hwecc_bch_capable(enum omap_ecc ecc_opt)
  27 {
  28         /* platforms which support all ECC schemes */
  29         if (soc_is_am33xx() || soc_is_am43xx() || cpu_is_omap44xx() ||
  30                  soc_is_omap54xx() || soc_is_dra7xx())
  31                 return 1;
  32
  33         if (ecc_opt == OMAP_ECC_BCH4_CODE_HW_DETECTION_SW ||
  34                  ecc_opt == OMAP_ECC_BCH8_CODE_HW_DETECTION_SW) {
  35                 if (cpu_is_omap24xx())
  36                         return 0;
  37                 else if (cpu_is_omap3630() && (GET_OMAP_REVISION() == 0))
  38                         return 0;
  39                 else
  40                         return 1;
  41         }
  42
  43         /* OMAP3xxx do not have ELM engine, so cannot support ECC schemes
  44          * which require H/W based ECC error detection */
  45         if ((cpu_is_omap34xx() || cpu_is_omap3630()) &&
  46             ((ecc_opt == OMAP_ECC_BCH4_CODE_HW) ||
  47                  (ecc_opt == OMAP_ECC_BCH8_CODE_HW)))
  48                 return 0;
  49
  50         /* legacy platforms support only HAM1 (1-bit Hamming) ECC scheme */
  51         if (ecc_opt == OMAP_ECC_HAM1_CODE_HW ||
  52             ecc_opt == OMAP_ECC_HAM1_CODE_SW)
  53                 return 1;
  54         else
  55                 return 0;
  56 }
  57
  58 /* This function will go away once the device-tree convertion is complete */
  59 static void gpmc_set_legacy(struct omap_nand_platform_data *gpmc_nand_data,
  60                             struct gpmc_settings *s)
  61 {
  62         /* Enable RD PIN Monitoring Reg */
  63         if (gpmc_nand_data->dev_ready) {
  64                 s->wait_on_read = true;
  65                 s->wait_on_write = true;
  66         }
  67
  68         if (gpmc_nand_data->devsize == NAND_BUSWIDTH_16)
  69                 s->device_width = GPMC_DEVWIDTH_16BIT;
  70         else
  71                 s->device_width = GPMC_DEVWIDTH_8BIT;
  72 }
  73
  74 int gpmc_nand_init(struct omap_nand_platform_data *gpmc_nand_data,
  75                    struct gpmc_timings *gpmc_t)
  76 {
  77         int err = 0;
  78         struct gpmc_settings s;
  79         struct platform_device *pdev;
  80         struct resource gpmc_nand_res[] = {
  81                 { .flags = IORESOURCE_MEM, },
  82                 { .flags = IORESOURCE_IRQ, },
  83                 { .flags = IORESOURCE_IRQ, },
  84         };
  85
  86         BUG_ON(gpmc_nand_data->cs >= GPMC_CS_NUM);
  87
  88         err = gpmc_cs_request(gpmc_nand_data->cs, NAND_IO_SIZE,
  89                               (unsigned long *)&gpmc_nand_res[0].start);
  90         if (err < 0) {
  91                 pr_err("omap2-gpmc: Cannot request GPMC CS %d, error %d\n",
  92                        gpmc_nand_data->cs, err);
  93                 return err;
  94         }
  95         gpmc_nand_res[0].end = gpmc_nand_res[0].start + NAND_IO_SIZE - 1;
  96         gpmc_nand_res[1].start = gpmc_get_client_irq(GPMC_IRQ_FIFOEVENTENABLE);
  97         gpmc_nand_res[2].start = gpmc_get_client_irq(GPMC_IRQ_COUNT_EVENT);
  98
  99         memset(&s, 0, sizeof(struct gpmc_settings));
 100         if (gpmc_nand_data->of_node)
 101                 gpmc_read_settings_dt(gpmc_nand_data->of_node, &s);
 102         else
 103                 gpmc_set_legacy(gpmc_nand_data, &s);
 104
 105         s.device_nand = true;
 106
 107         if (gpmc_t) {
 108                 err = gpmc_cs_set_timings(gpmc_nand_data->cs, gpmc_t, &s);
 109                 if (err < 0) {
 110                         pr_err("omap2-gpmc: Unable to set gpmc timings: %d\n",
 111                                err);
 112                         return err;
 113                 }
 114         }
 115
 116         err = gpmc_cs_program_settings(gpmc_nand_data->cs, &s);
 117         if (err < 0)
 118                 goto out_free_cs;
 119
 120         err = gpmc_configure(GPMC_CONFIG_WP, 0);
 121         if (err < 0)
 122                 goto out_free_cs;
 123
 124         gpmc_update_nand_reg(&gpmc_nand_data->reg, gpmc_nand_data->cs);
 125
 126         if (!gpmc_hwecc_bch_capable(gpmc_nand_data->ecc_opt)) {
 127                 pr_err("omap2-nand: Unsupported NAND ECC scheme selected\n");
 128                 err = -EINVAL;
 129                 goto out_free_cs;
 130         }
 131
 132
 133         pdev = platform_device_alloc("omap2-nand", gpmc_nand_data->cs);
 134         if (pdev) {
 135                 err = platform_device_add_resources(pdev, gpmc_nand_res,
 136                                                     ARRAY_SIZE(gpmc_nand_res));
 137                 if (!err)
 138                         pdev->dev.platform_data = gpmc_nand_data;
 139         } else {
 140                 err = -ENOMEM;
 141         }
 142         if (err)
 143                 goto out_free_pdev;
 144
 145         err = platform_device_add(pdev);
 146         if (err) {
 147                 dev_err(&pdev->dev, "Unable to register NAND device\n");
 148                 goto out_free_pdev;
 149         }
 150
 151         return 0;
 152
 153 out_free_pdev:
 154         platform_device_put(pdev);
 155 out_free_cs:
 156         gpmc_cs_free(gpmc_nand_data->cs);
 157
 158         return err;
 159 }