Commit 02a595d5 authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Mark Brown
Browse files

spi: fsl-espi: eliminate spi nor flash read loop 



The fsl-espi driver contains a read loop that implicitely assumes that
the device to read from is a m25p80 SPI NOR flash (bytes 2 - 4 of the
first write transfer are interpreted as 3 byte flash address).

Now that we have such a read loop in the spi-nor driver and are able
to correctly indicate the message size limit of the controller,
the read loop can be removed from the fsl-espi driver.

Signed-off-by: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 5090cc6a

drivers/spi/spi-fsl-espi.c

+21 −70
Original line number Diff line number Diff line
@@ -258,23 +258,6 @@ static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t) 
	return mpc8xxx_spi->count;

}



static inline void fsl_espi_addr2cmd(unsigned int addr, u8 *cmd)

{

	if (cmd) {

		cmd[1] = (u8)(addr >> 16);

		cmd[2] = (u8)(addr >> 8);

		cmd[3] = (u8)(addr >> 0);

	}

}



static inline unsigned int fsl_espi_cmd2addr(u8 *cmd)

{

	if (cmd)

		return cmd[1] << 16 | cmd[2] << 8 | cmd[3] << 0;



	return 0;

}



static void fsl_espi_do_trans(struct spi_message *m,

				struct fsl_espi_transfer *tr)

{
@@ -366,29 +349,17 @@ static void fsl_espi_cmd_trans(struct spi_message *m, 
static void fsl_espi_rw_trans(struct spi_message *m,

				struct fsl_espi_transfer *trans, u8 *rx_buff)

{

	struct fsl_espi_transfer *espi_trans = trans;

	unsigned int total_len = espi_trans->len;

	struct spi_transfer *t;

	u8 *local_buf;

	u8 *rx_buf = rx_buff;

	unsigned int trans_len;

	unsigned int addr;

	unsigned int tx_only;

	unsigned int rx_pos = 0;

	unsigned int pos;

	int i, loop;

	unsigned int tx_only = 0;

	int i = 0;



	local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);

	if (!local_buf) {

		espi_trans->status = -ENOMEM;

		trans->status = -ENOMEM;

		return;

	}



	for (pos = 0, loop = 0; pos < total_len; pos += trans_len, loop++) {

		trans_len = total_len - pos;



		i = 0;

		tx_only = 0;

	list_for_each_entry(t, &m->transfers, transfer_list) {

		if (t->tx_buf) {

			memcpy(local_buf + i, t->tx_buf, t->len);
@@ -398,36 +369,16 @@ static void fsl_espi_rw_trans(struct spi_message *m, 
		}

	}



		/* Add additional TX bytes to compensate SPCOM_TRANLEN_MAX */

		if (loop > 0)

			trans_len += tx_only;



		if (trans_len > SPCOM_TRANLEN_MAX)

			trans_len = SPCOM_TRANLEN_MAX;



		/* Update device offset */

		if (pos > 0) {

			addr = fsl_espi_cmd2addr(local_buf);

			addr += rx_pos;

			fsl_espi_addr2cmd(addr, local_buf);

		}

	trans->tx_buf = local_buf;

	trans->rx_buf = local_buf;

	fsl_espi_do_trans(m, trans);



		espi_trans->len = trans_len;

		espi_trans->tx_buf = local_buf;

		espi_trans->rx_buf = local_buf;

		fsl_espi_do_trans(m, espi_trans);



		/* If there is at least one RX byte then copy it to rx_buf */

		if (tx_only < SPCOM_TRANLEN_MAX)

			memcpy(rx_buf + rx_pos, espi_trans->rx_buf + tx_only,

					trans_len - tx_only);



		rx_pos += trans_len - tx_only;



		if (loop > 0)

			espi_trans->actual_length += espi_trans->len - tx_only;

		else

			espi_trans->actual_length += espi_trans->len;

	if (!trans->status) {

		/* If there is at least one RX byte then copy it to rx_buff */

		if (trans->len > tx_only)

			memcpy(rx_buff, trans->rx_buf + tx_only,

			       trans->len - tx_only);

		trans->actual_length += trans->len;

	}



	kfree(local_buf);
@@ -663,7 +614,7 @@ static int fsl_espi_runtime_resume(struct device *dev) 
}

#endif



static size_t fsl_espi_max_transfer_size(struct spi_device *spi)

static size_t fsl_espi_max_message_size(struct spi_device *spi)

{

	return SPCOM_TRANLEN_MAX;

}
@@ -695,7 +646,7 @@ static struct spi_master * fsl_espi_probe(struct device *dev, 
	master->cleanup = fsl_espi_cleanup;

	master->transfer_one_message = fsl_espi_do_one_msg;

	master->auto_runtime_pm = true;

	master->max_transfer_size = fsl_espi_max_transfer_size;

	master->max_message_size = fsl_espi_max_message_size;



	mpc8xxx_spi = spi_master_get_devdata(master);

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