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mtd: bcm47xxsflash: implement polling chip status 

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Rafał Miłecki 2013-03-24 21:51:31 +01:00 committed by David Woodhouse
parent 265dfbd9ae
commit bddcb5e7ca
1 changed files with 55 additions and 0 deletions
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55
drivers/mtd/devices/bcm47xxsflash.c
View File

@ -1,6 +1,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/mtd/mtd.h>
#include <linux/platform_device.h>
#include <linux/bcma/bcma.h>
@ -12,6 +13,57 @@ MODULE_DESCRIPTION("Serial flash driver for BCMA bus");
static const char * const probes[] = { "bcm47xxpart", NULL };
/**************************************************
* Various helpers
**************************************************/
static void bcm47xxsflash_cmd(struct bcm47xxsflash *b47s, u32 opcode)
{
int i;
b47s->cc_write(b47s, BCMA_CC_FLASHCTL, BCMA_CC_FLASHCTL_START | opcode);
for (i = 0; i < 1000; i++) {
if (!(b47s->cc_read(b47s, BCMA_CC_FLASHCTL) &
BCMA_CC_FLASHCTL_BUSY))
return;
cpu_relax();
}
pr_err("Control command failed (timeout)!\n");
}
static int bcm47xxsflash_poll(struct bcm47xxsflash *b47s, int timeout)
{
unsigned long deadline = jiffies + timeout;
do {
switch (b47s->type) {
case BCM47XXSFLASH_TYPE_ST:
bcm47xxsflash_cmd(b47s, OPCODE_ST_RDSR);
if (!(b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
SR_ST_WIP))
return 0;
break;
case BCM47XXSFLASH_TYPE_ATMEL:
bcm47xxsflash_cmd(b47s, OPCODE_AT_STATUS);
if (b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
SR_AT_READY)
return 0;
break;
}
cpu_relax();
udelay(1);
} while (!time_after_eq(jiffies, deadline));
pr_err("Timeout waiting for flash to be ready!\n");
return -EBUSY;
}
/**************************************************
* MTD ops
**************************************************/
static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
@ -97,6 +149,9 @@ static int bcm47xxsflash_bcma_probe(struct platform_device *pdev)
goto err_dev_reg;
}
if (bcm47xxsflash_poll(b47s, HZ / 10))
pr_warn("Serial flash busy\n");
return 0;
err_dev_reg: