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| author | Wolfram Sang <wsa+renesas@sang-engineering.com> | 2022-04-05 12:07:56 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2022-04-15 23:36:18 +0200 |
| commit | 633c0e7559ea88d2cbd5a6a06d6accfddf55542f (patch) | |
| tree | 29687c5b4cf9871a86ca494645900615b828e353 /drivers/i2c | |
| parent | c562570e00799c919d64e793e5b4c334d6978ce2 (diff) | |
| download | linux-633c0e7559ea88d2cbd5a6a06d6accfddf55542f.tar.gz linux-633c0e7559ea88d2cbd5a6a06d6accfddf55542f.tar.bz2 linux-633c0e7559ea88d2cbd5a6a06d6accfddf55542f.zip | |
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: Bhuvanesh Surachari <bhuvanesh_surachari@mentor.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-rcar.c | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 0db3d7559066..ca61dbe218bf 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -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; |