[PATCH 1/2] aspeed/i2c: Handle receive command in separate function

From: Guenter Roeck
Date: Wed Sep 12 2018 - 19:35:20 EST


Receive command handling may have to be deferred if a previous receive
done interrupt was not yet acknowledged. Move receive command handling
into a separate function to prepare for the necessary changes.

Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
hw/i2c/aspeed_i2c.c | 37 +++++++++++++++++++++----------------
1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/hw/i2c/aspeed_i2c.c b/hw/i2c/aspeed_i2c.c
index de6b083..d81f865 100644
--- a/hw/i2c/aspeed_i2c.c
+++ b/hw/i2c/aspeed_i2c.c
@@ -192,6 +192,26 @@ static uint8_t aspeed_i2c_get_state(AspeedI2CBus *bus)
return (bus->cmd >> I2CD_TX_STATE_SHIFT) & I2CD_TX_STATE_MASK;
}

+static void aspeed_i2c_handle_rx_cmd(AspeedI2CBus *bus)
+{
+ int ret;
+
+ aspeed_i2c_set_state(bus, I2CD_MRXD);
+ ret = i2c_recv(bus->bus);
+ if (ret < 0) {
+ qemu_log_mask(LOG_GUEST_ERROR, "%s: read failed\n", __func__);
+ ret = 0xff;
+ } else {
+ bus->intr_status |= I2CD_INTR_RX_DONE;
+ }
+ bus->buf = (ret & I2CD_BYTE_BUF_RX_MASK) << I2CD_BYTE_BUF_RX_SHIFT;
+ if (bus->cmd & I2CD_M_S_RX_CMD_LAST) {
+ i2c_nack(bus->bus);
+ }
+ bus->cmd &= ~(I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST);
+ aspeed_i2c_set_state(bus, I2CD_MACTIVE);
+}
+
/*
* The state machine needs some refinement. It is only used to track
* invalid STOP commands for the moment.
@@ -238,22 +258,7 @@ static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value)
}

if (bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST)) {
- int ret;
-
- aspeed_i2c_set_state(bus, I2CD_MRXD);
- ret = i2c_recv(bus->bus);
- if (ret < 0) {
- qemu_log_mask(LOG_GUEST_ERROR, "%s: read failed\n", __func__);
- ret = 0xff;
- } else {
- bus->intr_status |= I2CD_INTR_RX_DONE;
- }
- bus->buf = (ret & I2CD_BYTE_BUF_RX_MASK) << I2CD_BYTE_BUF_RX_SHIFT;
- if (bus->cmd & I2CD_M_S_RX_CMD_LAST) {
- i2c_nack(bus->bus);
- }
- bus->cmd &= ~(I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST);
- aspeed_i2c_set_state(bus, I2CD_MACTIVE);
+ aspeed_i2c_handle_rx_cmd(bus);
}

if (bus->cmd & I2CD_M_STOP_CMD) {
--
2.7.4


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