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From 71d6267980d7590e38059a784785ca158e361f87 Mon Sep 17 00:00:00 2001
From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Date: Fri, 4 Oct 2013 15:30:38 -0300
Subject: [PATCH 130/203] mtd: nand: pxa3xx: Allocate data buffer on detected
flash size
This commit replaces the currently hardcoded buffer size, by a
dynamic detection scheme. First a small 256 bytes buffer is allocated
so the device can be detected (using READID and friends commands).
After detection, this buffer is released and a new buffer is allocated
to acommodate the page size plus out-of-band size.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
---
drivers/mtd/nand/pxa3xx_nand.c | 45 ++++++++++++++++++++++++++++--------------
1 file changed, 30 insertions(+), 15 deletions(-)
--- a/drivers/mtd/nand/pxa3xx_nand.c
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -39,6 +39,13 @@
#define NAND_STOP_DELAY (2 * HZ/50)
#define PAGE_CHUNK_SIZE (2048)
+/*
+ * Define a buffer size for the initial command that detects the flash device:
+ * STATUS, READID and PARAM. The largest of these is the PARAM command,
+ * needing 256 bytes.
+ */
+#define INIT_BUFFER_SIZE 256
+
/* registers and bit definitions */
#define NDCR (0x00) /* Control register */
#define NDTR0CS0 (0x04) /* Timing Parameter 0 for CS0 */
@@ -164,6 +171,7 @@ struct pxa3xx_nand_info {
unsigned int buf_start;
unsigned int buf_count;
+ unsigned int buf_size;
/* DMA information */
int drcmr_dat;
@@ -911,26 +919,20 @@ static int pxa3xx_nand_detect_config(str
return 0;
}
-/* the maximum possible buffer size for large page with OOB data
- * is: 2048 + 64 = 2112 bytes, allocate a page here for both the
- * data buffer and the DMA descriptor
- */
-#define MAX_BUFF_SIZE PAGE_SIZE
-
#ifdef ARCH_HAS_DMA
static int pxa3xx_nand_init_buff(struct pxa3xx_nand_info *info)
{
struct platform_device *pdev = info->pdev;
- int data_desc_offset = MAX_BUFF_SIZE - sizeof(struct pxa_dma_desc);
+ int data_desc_offset = info->buf_size - sizeof(struct pxa_dma_desc);
if (use_dma == 0) {
- info->data_buff = kmalloc(MAX_BUFF_SIZE, GFP_KERNEL);
+ info->data_buff = kmalloc(info->buf_size, GFP_KERNEL);
if (info->data_buff == NULL)
return -ENOMEM;
return 0;
}
- info->data_buff = dma_alloc_coherent(&pdev->dev, MAX_BUFF_SIZE,
+ info->data_buff = dma_alloc_coherent(&pdev->dev, info->buf_size,
&info->data_buff_phys, GFP_KERNEL);
if (info->data_buff == NULL) {
dev_err(&pdev->dev, "failed to allocate dma buffer\n");
@@ -944,7 +946,7 @@ static int pxa3xx_nand_init_buff(struct
pxa3xx_nand_data_dma_irq, info);
if (info->data_dma_ch < 0) {
dev_err(&pdev->dev, "failed to request data dma\n");
- dma_free_coherent(&pdev->dev, MAX_BUFF_SIZE,
+ dma_free_coherent(&pdev->dev, info->buf_size,
info->data_buff, info->data_buff_phys);
return info->data_dma_ch;
}
@@ -962,7 +964,7 @@ static void pxa3xx_nand_free_buff(struct
struct platform_device *pdev = info->pdev;
if (use_dma) {
pxa_free_dma(info->data_dma_ch);
- dma_free_coherent(&pdev->dev, MAX_BUFF_SIZE,
+ dma_free_coherent(&pdev->dev, info->buf_size,
info->data_buff, info->data_buff_phys);
} else {
kfree(info->data_buff);
@@ -971,7 +973,7 @@ static void pxa3xx_nand_free_buff(struct
#else
static int pxa3xx_nand_init_buff(struct pxa3xx_nand_info *info)
{
- info->data_buff = kmalloc(MAX_BUFF_SIZE, GFP_KERNEL);
+ info->data_buff = kmalloc(info->buf_size, GFP_KERNEL);
if (info->data_buff == NULL)
return -ENOMEM;
return 0;
@@ -1085,7 +1087,16 @@ KEEP_CONFIG:
else
host->col_addr_cycles = 1;
+ /* release the initial buffer */
+ kfree(info->data_buff);
+
+ /* allocate the real data + oob buffer */
+ info->buf_size = mtd->writesize + mtd->oobsize;
+ ret = pxa3xx_nand_init_buff(info);
+ if (ret)
+ return ret;
info->oob_buff = info->data_buff + mtd->writesize;
+
if ((mtd->size >> chip->page_shift) > 65536)
host->row_addr_cycles = 3;
else
@@ -1191,9 +1202,13 @@ static int alloc_nand_resource(struct pl
}
info->mmio_phys = r->start;
- ret = pxa3xx_nand_init_buff(info);
- if (ret)
+ /* Allocate a buffer to allow flash detection */
+ info->buf_size = INIT_BUFFER_SIZE;
+ info->data_buff = kmalloc(info->buf_size, GFP_KERNEL);
+ if (info->data_buff == NULL) {
+ ret = -ENOMEM;
goto fail_disable_clk;
+ }
/* initialize all interrupts to be disabled */
disable_int(info, NDSR_MASK);
@@ -1211,7 +1226,7 @@ static int alloc_nand_resource(struct pl
fail_free_buf:
free_irq(irq, info);
- pxa3xx_nand_free_buff(info);
+ kfree(info->data_buff);
fail_disable_clk:
clk_disable_unprepare(info->clk);
return ret;
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