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@xxxxxxxxxx>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@xxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---
For testing, I wired a Lager board (R-Car H2) and a Salvator-XS (R-Car
H3 ES2.0) together. The Lager board ran the testunit and provided SMBus
Proc Calls. The Salvator-XS board was requesting the data.
Compared to my previous version: sending 1 byte works now, sending with
DMA as well. Invalid sizes are detected, too. This is as much as I can
test, I'd think.
Compared to Bhuvanesh + Andrew's last version: less intrusive and more
self contained (no goto), Proc Calls are covered as well
I tried some other refactoring as well (like one single place where
rcar_i2c_dma() is called) but IMHO this is the most readable solution.
Thank you everyone for working on this. I am very interested in your
comments and test results!
drivers/i2c/busses/i2c-rcar.c | 31 +++++++++++++++++++++++++++----
1 file changed, 27 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index f71c730f9838..f45991252993 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;
--
2.30.2
