Unverified Commit 8941cd8d authored by Patrice Chotard's avatar Patrice Chotard Committed by Mark Brown
Browse files

mtd: spinand: use the spi-mem poll status APIs 



Make use of spi-mem poll status APIs to let advanced controllers
optimize wait operations.
This should also fix the high CPU usage for system that don't have
a dedicated STATUS poll block logic.

Signed-off-by: default avatarPatrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: default avatarChristophe Kerello <christophe.kerello@foss.st.com>
Reviewed-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Acked-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20210518162754.15940-3-patrice.chotard@foss.st.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent c955a0cc

drivers/mtd/nand/spi/core.c

+32 −13
Original line number Diff line number Diff line
@@ -473,20 +473,26 @@ static int spinand_erase_op(struct spinand_device *spinand, 
	return spi_mem_exec_op(spinand->spimem, &op);

}



static int spinand_wait(struct spinand_device *spinand, u8 *s)

static int spinand_wait(struct spinand_device *spinand,

			unsigned long initial_delay_us,

			unsigned long poll_delay_us,

			u8 *s)

{

	unsigned long timeo =  jiffies + msecs_to_jiffies(400);

	struct spi_mem_op op = SPINAND_GET_FEATURE_OP(REG_STATUS,

						      spinand->scratchbuf);

	u8 status;

	int ret;



	do {

		ret = spinand_read_status(spinand, &status);

	ret = spi_mem_poll_status(spinand->spimem, &op, STATUS_BUSY, 0,

				  initial_delay_us,

				  poll_delay_us,

				  SPINAND_WAITRDY_TIMEOUT_MS);

	if (ret)

		return ret;



	status = *spinand->scratchbuf;

	if (!(status & STATUS_BUSY))

		goto out;

	} while (time_before(jiffies, timeo));



	/*

	 * Extra read, just in case the STATUS_READY bit has changed
@@ -526,7 +532,10 @@ static int spinand_reset_op(struct spinand_device *spinand) 
	if (ret)

		return ret;



	return spinand_wait(spinand, NULL);

	return spinand_wait(spinand,

			    SPINAND_RESET_INITIAL_DELAY_US,

			    SPINAND_RESET_POLL_DELAY_US,

			    NULL);

}



static int spinand_lock_block(struct spinand_device *spinand, u8 lock)
@@ -549,7 +558,10 @@ static int spinand_read_page(struct spinand_device *spinand, 
	if (ret)

		return ret;



	ret = spinand_wait(spinand, &status);

	ret = spinand_wait(spinand,

			   SPINAND_READ_INITIAL_DELAY_US,

			   SPINAND_READ_POLL_DELAY_US,

			   &status);

	if (ret < 0)

		return ret;
@@ -585,7 +597,10 @@ static int spinand_write_page(struct spinand_device *spinand, 
	if (ret)

		return ret;



	ret = spinand_wait(spinand, &status);

	ret = spinand_wait(spinand,

			   SPINAND_WRITE_INITIAL_DELAY_US,

			   SPINAND_WRITE_POLL_DELAY_US,

			   &status);

	if (!ret && (status & STATUS_PROG_FAILED))

		return -EIO;
@@ -768,7 +783,11 @@ static int spinand_erase(struct nand_device *nand, const struct nand_pos *pos) 
	if (ret)

		return ret;



	ret = spinand_wait(spinand, &status);

	ret = spinand_wait(spinand,

			   SPINAND_ERASE_INITIAL_DELAY_US,

			   SPINAND_ERASE_POLL_DELAY_US,

			   &status);



	if (!ret && (status & STATUS_ERASE_FAILED))

		ret = -EIO;

include/linux/mtd/spinand.h

+22 −0
Original line number Diff line number Diff line
@@ -170,6 +170,28 @@ struct spinand_op; 
struct spinand_device;



#define SPINAND_MAX_ID_LEN	4

/*

 * For erase, write and read operation, we got the following timings :

 * tBERS (erase) 1ms to 4ms

 * tPROG 300us to 400us

 * tREAD 25us to 100us

 * In order to minimize latency, the min value is divided by 4 for the

 * initial delay, and dividing by 20 for the poll delay.

 * For reset, 5us/10us/500us if the device is respectively

 * reading/programming/erasing when the RESET occurs. Since we always

 * issue a RESET when the device is IDLE, 5us is selected for both initial

 * and poll delay.

 */

#define SPINAND_READ_INITIAL_DELAY_US	6

#define SPINAND_READ_POLL_DELAY_US	5

#define SPINAND_RESET_INITIAL_DELAY_US	5

#define SPINAND_RESET_POLL_DELAY_US	5

#define SPINAND_WRITE_INITIAL_DELAY_US	75

#define SPINAND_WRITE_POLL_DELAY_US	15

#define SPINAND_ERASE_INITIAL_DELAY_US	250

#define SPINAND_ERASE_POLL_DELAY_US	50



#define SPINAND_WAITRDY_TIMEOUT_MS	400



/**

 * struct spinand_id - SPI NAND id structure