target/linux/mvebu/patches-3.10/0130-mtd-nand-pxa3xx-Allocate-data-buffer-on-detected-fla.patch

   1 From 71d6267980d7590e38059a784785ca158e361f87 Mon Sep 17 00:00:00 2001
   2 From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
   3 Date: Fri, 4 Oct 2013 15:30:38 -0300
   4 Subject: [PATCH 130/203] mtd: nand: pxa3xx: Allocate data buffer on detected
   5  flash size
   6
   7 This commit replaces the currently hardcoded buffer size, by a
   8 dynamic detection scheme. First a small 256 bytes buffer is allocated
   9 so the device can be detected (using READID and friends commands).
  10
  11 After detection, this buffer is released and a new buffer is allocated
  12 to acommodate the page size plus out-of-band size.
  13
  14 Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
  15 Tested-by: Daniel Mack <zonque@gmail.com>
  16 Signed-off-by: Brian Norris <computersforpeace@gmail.com>
  17 ---
  18  drivers/mtd/nand/pxa3xx_nand.c | 45 ++++++++++++++++++++++++++++--------------
  19  1 file changed, 30 insertions(+), 15 deletions(-)
  20
  21 --- a/drivers/mtd/nand/pxa3xx_nand.c
  22 +++ b/drivers/mtd/nand/pxa3xx_nand.c
  23 @@ -39,6 +39,13 @@
  24  #define NAND_STOP_DELAY                (2 * HZ/50)
  25  #define PAGE_CHUNK_SIZE                (2048)
  26
  27 +/*
  28 + * Define a buffer size for the initial command that detects the flash device:
  29 + * STATUS, READID and PARAM. The largest of these is the PARAM command,
  30 + * needing 256 bytes.
  31 + */
  32 +#define INIT_BUFFER_SIZE       256
  33 +
  34  /* registers and bit definitions */
  35  #define NDCR           (0x00) /* Control register */
  36  #define NDTR0CS0       (0x04) /* Timing Parameter 0 for CS0 */
  37 @@ -164,6 +171,7 @@ struct pxa3xx_nand_info {
  38
  39         unsigned int            buf_start;
  40         unsigned int            buf_count;
  41 +       unsigned int            buf_size;
  42
  43         /* DMA information */
  44         int                     drcmr_dat;
  45 @@ -911,26 +919,20 @@ static int pxa3xx_nand_detect_config(str
  46         return 0;
  47  }
  48
  49 -/* the maximum possible buffer size for large page with OOB data
  50 - * is: 2048 + 64 = 2112 bytes, allocate a page here for both the
  51 - * data buffer and the DMA descriptor
  52 - */
  53 -#define MAX_BUFF_SIZE  PAGE_SIZE
  54 -
  55  #ifdef ARCH_HAS_DMA
  56  static int pxa3xx_nand_init_buff(struct pxa3xx_nand_info *info)
  57  {
  58         struct platform_device *pdev = info->pdev;
  59 -       int data_desc_offset = MAX_BUFF_SIZE - sizeof(struct pxa_dma_desc);
  60 +       int data_desc_offset = info->buf_size - sizeof(struct pxa_dma_desc);
  61
  62         if (use_dma == 0) {
  63 -               info->data_buff = kmalloc(MAX_BUFF_SIZE, GFP_KERNEL);
  64 +               info->data_buff = kmalloc(info->buf_size, GFP_KERNEL);
  65                 if (info->data_buff == NULL)
  66                         return -ENOMEM;
  67                 return 0;
  68         }
  69
  70 -       info->data_buff = dma_alloc_coherent(&pdev->dev, MAX_BUFF_SIZE,
  71 +       info->data_buff = dma_alloc_coherent(&pdev->dev, info->buf_size,
  72                                 &info->data_buff_phys, GFP_KERNEL);
  73         if (info->data_buff == NULL) {
  74                 dev_err(&pdev->dev, "failed to allocate dma buffer\n");
  75 @@ -944,7 +946,7 @@ static int pxa3xx_nand_init_buff(struct
  76                                 pxa3xx_nand_data_dma_irq, info);
  77         if (info->data_dma_ch < 0) {
  78                 dev_err(&pdev->dev, "failed to request data dma\n");
  79 -               dma_free_coherent(&pdev->dev, MAX_BUFF_SIZE,
  80 +               dma_free_coherent(&pdev->dev, info->buf_size,
  81                                 info->data_buff, info->data_buff_phys);
  82                 return info->data_dma_ch;
  83         }
  84 @@ -962,7 +964,7 @@ static void pxa3xx_nand_free_buff(struct
  85         struct platform_device *pdev = info->pdev;
  86         if (use_dma) {
  87                 pxa_free_dma(info->data_dma_ch);
  88 -               dma_free_coherent(&pdev->dev, MAX_BUFF_SIZE,
  89 +               dma_free_coherent(&pdev->dev, info->buf_size,
  90                                   info->data_buff, info->data_buff_phys);
  91         } else {
  92                 kfree(info->data_buff);
  93 @@ -971,7 +973,7 @@ static void pxa3xx_nand_free_buff(struct
  94  #else
  95  static int pxa3xx_nand_init_buff(struct pxa3xx_nand_info *info)
  96  {
  97 -       info->data_buff = kmalloc(MAX_BUFF_SIZE, GFP_KERNEL);
  98 +       info->data_buff = kmalloc(info->buf_size, GFP_KERNEL);
  99         if (info->data_buff == NULL)
 100                 return -ENOMEM;
 101         return 0;
 102 @@ -1085,7 +1087,16 @@ KEEP_CONFIG:
 103         else
 104                 host->col_addr_cycles = 1;
 105
 106 +       /* release the initial buffer */
 107 +       kfree(info->data_buff);
 108 +
 109 +       /* allocate the real data + oob buffer */
 110 +       info->buf_size = mtd->writesize + mtd->oobsize;
 111 +       ret = pxa3xx_nand_init_buff(info);
 112 +       if (ret)
 113 +               return ret;
 114         info->oob_buff = info->data_buff + mtd->writesize;
 115 +
 116         if ((mtd->size >> chip->page_shift) > 65536)
 117                 host->row_addr_cycles = 3;
 118         else
 119 @@ -1191,9 +1202,13 @@ static int alloc_nand_resource(struct pl
 120         }
 121         info->mmio_phys = r->start;
 122
 123 -       ret = pxa3xx_nand_init_buff(info);
 124 -       if (ret)
 125 +       /* Allocate a buffer to allow flash detection */
 126 +       info->buf_size = INIT_BUFFER_SIZE;
 127 +       info->data_buff = kmalloc(info->buf_size, GFP_KERNEL);
 128 +       if (info->data_buff == NULL) {
 129 +               ret = -ENOMEM;
 130                 goto fail_disable_clk;
 131 +       }
 132
 133         /* initialize all interrupts to be disabled */
 134         disable_int(info, NDSR_MASK);
 135 @@ -1211,7 +1226,7 @@ static int alloc_nand_resource(struct pl
 136
 137  fail_free_buf:
 138         free_irq(irq, info);
 139 -       pxa3xx_nand_free_buff(info);
 140 +       kfree(info->data_buff);
 141  fail_disable_clk:
 142         clk_disable_unprepare(info->clk);
 143         return ret;