From bb626e5b43df996a19b53cb6033b25d83f7b2e73 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Tue, 25 Sep 2018 14:02:31 +0100 Subject: aspeed/i2c: Fix receive done interrupt handling MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The AST2500 datasheet says: I2CD10 Interrupt Status Register bit 2 Receive Done Interrupt status S/W needs to clear this status bit to allow next data receiving The Rx interrupt done interrupt status bit needs to be cleared explicitly before the next byte can be received, and must therefore not be auto-cleared. Also, receiving the next byte must be delayed until the bit has been cleared. Signed-off-by: Guenter Roeck Signed-off-by: Cédric Le Goater Message-id: 20180914063506.20815-4-clg@kaod.org Signed-off-by: Peter Maydell --- hw/i2c/aspeed_i2c.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'hw/i2c') diff --git a/hw/i2c/aspeed_i2c.c b/hw/i2c/aspeed_i2c.c index ce16efc136..a2dfa82760 100644 --- a/hw/i2c/aspeed_i2c.c +++ b/hw/i2c/aspeed_i2c.c @@ -252,7 +252,8 @@ static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value) aspeed_i2c_set_state(bus, I2CD_MACTIVE); } - if (bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST)) { + if ((bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST)) && + !(bus->intr_status & I2CD_INTR_RX_DONE)) { aspeed_i2c_handle_rx_cmd(bus); } @@ -274,6 +275,7 @@ static void aspeed_i2c_bus_write(void *opaque, hwaddr offset, uint64_t value, unsigned size) { AspeedI2CBus *bus = opaque; + bool handle_rx; switch (offset) { case I2CD_FUN_CTRL_REG: @@ -294,11 +296,17 @@ static void aspeed_i2c_bus_write(void *opaque, hwaddr offset, bus->intr_ctrl = value & 0x7FFF; break; case I2CD_INTR_STS_REG: + handle_rx = (bus->intr_status & I2CD_INTR_RX_DONE) && + (value & I2CD_INTR_RX_DONE); bus->intr_status &= ~(value & 0x7FFF); if (!bus->intr_status) { bus->controller->intr_status &= ~(1 << bus->id); qemu_irq_lower(bus->controller->irq); } + if (handle_rx && (bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST))) { + aspeed_i2c_handle_rx_cmd(bus); + aspeed_i2c_bus_raise_interrupt(bus); + } break; case I2CD_DEV_ADDR_REG: qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n", -- cgit v1.2.3