[U-Boot] [PATCH 05/11] st_smi: Enhance the error handling

Amit Virdi
2012-02-24T12:23:08Z

This commit does the following:
- Reports error if SNOR flash is not found on the board
- Changes smi_read_sr to return error using which a retry mechanism is
implemented for reading flash status

Signed-off-by: Vipin Kumar <vipin.kumar@st.com>
Signed-off-by: Amit Virdi <amit.virdi@st.com>
---
drivers/mtd/st_smi.c | 34 +++++++++++++++++++++-------------
1 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/drivers/mtd/st_smi.c b/drivers/mtd/st_smi.c
index ec19b0d..ce50fc1 100644
--- a/drivers/mtd/st_smi.c
+++ b/drivers/mtd/st_smi.c
@@ -108,11 +108,17 @@ static ulong flash_get_size(ulong base, int banknum)
{
flash_info_t *info = &flash_info[banknum];
struct flash_dev *dev;
- unsigned int value;
+ int value;
unsigned int density;
int i;

value = smi_read_id(info, banknum);
+
+ if (value < 0) {
+ printf("Flash id could not be read\n");
+ return 0;
+ }
+
density = (value >> 16) & 0xff;

for (i = 0, dev = &flash_ids[0]; dev->density != 0x0;
@@ -140,7 +146,7 @@ static ulong flash_get_size(ulong base, int banknum)
* This routine will get the status register of the flash chip present at the
* given bank
*/
-static unsigned int smi_read_sr(int bank)
+static int smi_read_sr(int bank)
{
u32 ctrlreg1;

@@ -174,13 +180,11 @@ static unsigned int smi_read_sr(int bank)
*/
static int smi_wait_till_ready(int bank, int timeout)
{
- int count;
- unsigned int sr;
+ int sr;

/* One chip guarantees max 5 msec wait here after page writes,
but potentially three seconds (!) after page erase. */
- for (count = 0; count < timeout; count++) {
-
+ do {
sr = smi_read_sr(bank);
if (sr < 0)
break;
@@ -189,7 +193,8 @@ static int smi_wait_till_ready(int bank, int timeout)

/* Try again after 1m-sec */
udelay(1000);
- }
+ } while (timeout--);
+
printf("SMI controller is still in wait, timeout=%d\n", timeout);
return -EIO;
}
@@ -205,6 +210,7 @@ static int smi_write_enable(int bank)
{
u32 ctrlreg1;
int timeout = WMODE_TOUT;
+ int sr;

/* Store the CTRL REG1 state */
ctrlreg1 = readl(&smicntl->smi_cr1);
@@ -221,14 +227,16 @@ static int smi_write_enable(int bank)
/* Restore the CTRL REG1 state */
writel(ctrlreg1, &smicntl->smi_cr1);

- while (timeout--) {
- if (smi_read_sr(bank) & (1 << (bank + WM_SHIFT)))
+ do {
+ sr = smi_read_sr(bank);
+ if (sr < 0)
break;
- udelay(1000);
- }
+ else if (sr & (1 << (bank + WM_SHIFT)))
+ return 0;

- if (timeout)
- return 0;
+ /* Try again after 1m-sec */
+ udelay(1000);
+ } while (timeout--);

return -1;
}
--
1.7.2.2