Commit 633c0e75 authored by Wolfram Sang's avatar Wolfram Sang Committed by Wolfram Sang
Browse files

i2c: rcar: add support for I2C_M_RECV_LEN 



With this feature added, SMBus Block reads and Proc calls are now
supported. This patch is the best of two independent developments by
Wolfram and Bhuvanesh + Andrew, refactored again by Wolfram.

Signed-off-by: default avatarBhuvanesh Surachari <bhuvanesh_surachari@mentor.com>
Signed-off-by: default avatarAndrew Gabbasov <andrew_gabbasov@mentor.com>
Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: default avatarEugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: default avatarEugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent c562570e

drivers/i2c/busses/i2c-rcar.c

+27 −4
Original line number Diff line number Diff line
@@ -105,6 +105,7 @@ 
#define ID_DONE		(1 << 2)

#define ID_ARBLOST	(1 << 3)

#define ID_NACK		(1 << 4)

#define ID_EPROTO	(1 << 5)

/* persistent flags */

#define ID_P_HOST_NOTIFY	BIT(28)

#define ID_P_REP_AFTER_RD	BIT(29)
@@ -522,6 +523,7 @@ static void rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) 
static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)

{

	struct i2c_msg *msg = priv->msg;

	bool recv_len_init = priv->pos == 0 && msg->flags & I2C_M_RECV_LEN;



	/* FIXME: sometimes, unknown interrupt happened. Do nothing */

	if (!(msr & MDR))
@@ -535,12 +537,29 @@ static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) 
		rcar_i2c_dma(priv);

	} else if (priv->pos < msg->len) {

		/* get received data */

		msg->buf[priv->pos] = rcar_i2c_read(priv, ICRXTX);

		u8 data = rcar_i2c_read(priv, ICRXTX);



		msg->buf[priv->pos] = data;

		if (recv_len_init) {

			if (data == 0 || data > I2C_SMBUS_BLOCK_MAX) {

				priv->flags |= ID_DONE | ID_EPROTO;

				return;

			}

			msg->len += msg->buf[0];

			/* Enough data for DMA? */

			if (rcar_i2c_dma(priv))

				return;

			/* new length after RECV_LEN now properly initialized */

			recv_len_init = false;

		}

		priv->pos++;

	}



	/* If next received data is the _LAST_, go to new phase. */

	if (priv->pos + 1 == msg->len) {

	/*

	 * If next received data is the _LAST_ and we are not waiting for a new

	 * length because of RECV_LEN, then go to a new phase.

	 */

	if (priv->pos + 1 == msg->len && !recv_len_init) {

		if (priv->flags & ID_LAST_MSG) {

			rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);

		} else {
@@ -847,6 +866,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, 
		ret = -ENXIO;

	} else if (priv->flags & ID_ARBLOST) {

		ret = -EAGAIN;

	} else if (priv->flags & ID_EPROTO) {

		ret = -EPROTO;

	} else {

		ret = num - priv->msgs_left; /* The number of transfer */

	}
@@ -909,6 +930,8 @@ static int rcar_i2c_master_xfer_atomic(struct i2c_adapter *adap, 
		ret = -ENXIO;

	} else if (priv->flags & ID_ARBLOST) {

		ret = -EAGAIN;

	} else if (priv->flags & ID_EPROTO) {

		ret = -EPROTO;

	} else {

		ret = num - priv->msgs_left; /* The number of transfer */

	}
@@ -975,7 +998,7 @@ static u32 rcar_i2c_func(struct i2c_adapter *adap) 
	 * I2C_M_IGNORE_NAK (automatically sends STOP after NAK)

	 */

	u32 func = I2C_FUNC_I2C | I2C_FUNC_SLAVE |

		   (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);

		   (I2C_FUNC_SMBUS_EMUL_ALL & ~I2C_FUNC_SMBUS_QUICK);



	if (priv->flags & ID_P_HOST_NOTIFY)

		func |= I2C_FUNC_SMBUS_HOST_NOTIFY;