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kernel/linux-imx6_3.14.28/arch/arm/mach-omap2/gpmc-nand.c 3.49 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * gpmc-nand.c
   *
   * Copyright (C) 2009 Texas Instruments
   * Vimal Singh <vimalsingh@ti.com>
   *
   * 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.
   */
  
  #include <linux/kernel.h>
  #include <linux/platform_device.h>
  #include <linux/io.h>
  #include <linux/mtd/nand.h>
  #include <linux/platform_data/mtd-nand-omap2.h>
  
  #include <asm/mach/flash.h>
  
  #include "gpmc.h"
  #include "soc.h"
  #include "gpmc-nand.h"
  
  /* minimum size for IO mapping */
  #define	NAND_IO_SIZE	4
  
  static struct resource gpmc_nand_resource[] = {
  	{
  		.flags		= IORESOURCE_MEM,
  	},
  	{
  		.flags		= IORESOURCE_IRQ,
  	},
  	{
  		.flags		= IORESOURCE_IRQ,
  	},
  };
  
  static struct platform_device gpmc_nand_device = {
  	.name		= "omap2-nand",
  	.id		= 0,
  	.num_resources	= ARRAY_SIZE(gpmc_nand_resource),
  	.resource	= gpmc_nand_resource,
  };
  
  static bool gpmc_hwecc_bch_capable(enum omap_ecc ecc_opt)
  {
  	/* support only OMAP3 class */
  	if (!cpu_is_omap34xx() && !soc_is_am33xx()) {
  		pr_err("BCH ecc is not supported on this CPU
  ");
  		return 0;
  	}
  
  	/*
  	 * For now, assume 4-bit mode is only supported on OMAP3630 ES1.x, x>=1
  	 * and AM33xx derivates. Other chips may be added if confirmed to work.
  	 */
  	if ((ecc_opt == OMAP_ECC_BCH4_CODE_HW) &&
  	    (!cpu_is_omap3630() || (GET_OMAP_REVISION() == 0)) &&
  	    (!soc_is_am33xx())) {
  		pr_err("BCH 4-bit mode is not supported on this CPU
  ");
  		return 0;
  	}
  
  	return 1;
  }
  
  /* This function will go away once the device-tree convertion is complete */
  static void gpmc_set_legacy(struct omap_nand_platform_data *gpmc_nand_data,
  			    struct gpmc_settings *s)
  {
  	/* Enable RD PIN Monitoring Reg */
  	if (gpmc_nand_data->dev_ready) {
  		s->wait_on_read = true;
  		s->wait_on_write = true;
  	}
  
  	if (gpmc_nand_data->devsize == NAND_BUSWIDTH_16)
  		s->device_width = GPMC_DEVWIDTH_16BIT;
  	else
  		s->device_width = GPMC_DEVWIDTH_8BIT;
  }
  
  int gpmc_nand_init(struct omap_nand_platform_data *gpmc_nand_data,
  		   struct gpmc_timings *gpmc_t)
  {
  	int err	= 0;
  	struct gpmc_settings s;
  	struct device *dev = &gpmc_nand_device.dev;
  
  	memset(&s, 0, sizeof(struct gpmc_settings));
  
  	gpmc_nand_device.dev.platform_data = gpmc_nand_data;
  
  	err = gpmc_cs_request(gpmc_nand_data->cs, NAND_IO_SIZE,
  				(unsigned long *)&gpmc_nand_resource[0].start);
  	if (err < 0) {
  		dev_err(dev, "Cannot request GPMC CS %d, error %d
  ",
  			gpmc_nand_data->cs, err);
  		return err;
  	}
  
  	gpmc_nand_resource[0].end = gpmc_nand_resource[0].start +
  							NAND_IO_SIZE - 1;
  
  	gpmc_nand_resource[1].start =
  				gpmc_get_client_irq(GPMC_IRQ_FIFOEVENTENABLE);
  	gpmc_nand_resource[2].start =
  				gpmc_get_client_irq(GPMC_IRQ_COUNT_EVENT);
  
  	if (gpmc_t) {
  		err = gpmc_cs_set_timings(gpmc_nand_data->cs, gpmc_t);
  		if (err < 0) {
  			dev_err(dev, "Unable to set gpmc timings: %d
  ", err);
  			return err;
  		}
  	}
  
  	if (gpmc_nand_data->of_node)
  		gpmc_read_settings_dt(gpmc_nand_data->of_node, &s);
  	else
  		gpmc_set_legacy(gpmc_nand_data, &s);
  
  	s.device_nand = true;
  
  	err = gpmc_cs_program_settings(gpmc_nand_data->cs, &s);
  	if (err < 0)
  		goto out_free_cs;
  
  	err = gpmc_configure(GPMC_CONFIG_WP, 0);
  	if (err < 0)
  		goto out_free_cs;
  
  	gpmc_update_nand_reg(&gpmc_nand_data->reg, gpmc_nand_data->cs);
  
  	if (!gpmc_hwecc_bch_capable(gpmc_nand_data->ecc_opt))
  		return -EINVAL;
  
  	err = platform_device_register(&gpmc_nand_device);
  	if (err < 0) {
  		dev_err(dev, "Unable to register NAND device
  ");
  		goto out_free_cs;
  	}
  
  	return 0;
  
  out_free_cs:
  	gpmc_cs_free(gpmc_nand_data->cs);
  
  	return err;
  }