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Commit bddcb5e7 authored by Rafał Miłecki's avatar Rafał Miłecki Committed by David Woodhouse
Browse files

mtd: bcm47xxsflash: implement polling chip status 



Signed-off-by: default avatarRafał Miłecki <zajec5@gmail.com>
Signed-off-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 265dfbd9

drivers/mtd/devices/bcm47xxsflash.c

+55 −0
Original line number Diff line number Diff line 
#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: