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[Qemu-devel] [PATCH 01/13] ssi: Support for multiple attached devices
From: |
Peter Crosthwaite |
Subject: |
[Qemu-devel] [PATCH 01/13] ssi: Support for multiple attached devices |
Date: |
Wed, 10 Oct 2012 10:46:34 +1000 |
From: Peter A. G. Crosthwaite <address@hidden>
Removed assertion that only one device is attached to the SSI bus.
When multiple devices are attached, all slaves have their transfer function
called for transfers. Each device is responsible for knowing whether or not its
CS is active, and if not returning 0. The returned data is the logical or of
all responses from the (mulitple) devices.
Signed-off-by: Peter A. G. Crosthwaite <address@hidden>
Acked-by: Peter Maydell <address@hidden>
---
hw/ssi.c | 24 +++++++++---------------
1 files changed, 9 insertions(+), 15 deletions(-)
diff --git a/hw/ssi.c b/hw/ssi.c
index e5f14a0..35d0a04 100644
--- a/hw/ssi.c
+++ b/hw/ssi.c
@@ -2,6 +2,8 @@
* QEMU Synchronous Serial Interface support
*
* Copyright (c) 2009 CodeSourcery.
+ * Copyright (c) 2012 Peter A.G. Crosthwaite (address@hidden)
+ * Copyright (c) 2012 PetaLogix Pty Ltd.
* Written by Paul Brook
*
* This code is licensed under the GNU GPL v2.
@@ -29,14 +31,6 @@ static int ssi_slave_init(DeviceState *dev)
{
SSISlave *s = SSI_SLAVE(dev);
SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
- SSIBus *bus;
- BusChild *kid;
-
- bus = FROM_QBUS(SSIBus, qdev_get_parent_bus(dev));
- kid = QTAILQ_FIRST(&bus->qbus.children);
- if (kid->child != dev || QTAILQ_NEXT(kid, sibling) != NULL) {
- hw_error("Too many devices on SSI bus");
- }
return ssc->init(s);
}
@@ -74,16 +68,16 @@ SSIBus *ssi_create_bus(DeviceState *parent, const char
*name)
uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
{
BusChild *kid;
- SSISlave *slave;
SSISlaveClass *ssc;
+ uint32_t r = 0;
- kid = QTAILQ_FIRST(&bus->qbus.children);
- if (!kid) {
- return 0;
+ QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
+ SSISlave *slave = SSI_SLAVE(kid->child);
+ ssc = SSI_SLAVE_GET_CLASS(slave);
+ r |= ssc->transfer(slave, val);
}
- slave = SSI_SLAVE(kid->child);
- ssc = SSI_SLAVE_GET_CLASS(slave);
- return ssc->transfer(slave, val);
+
+ return r;
}
static void ssi_slave_register_types(void)
--
1.7.0.4
- [Qemu-devel] [PULL 0/13] Ehnahced SSI bus support + M25P80 SPI flash + Xilinx SPI controller, Peter Crosthwaite, 2012/10/09
- [Qemu-devel] [PATCH 01/13] ssi: Support for multiple attached devices,
Peter Crosthwaite <=
- [Qemu-devel] [PATCH 02/13] ssi: Implemented CS behaviour, Peter Crosthwaite, 2012/10/09
- [Qemu-devel] [PATCH 03/13] ssi: Added create_slave_no_init(), Peter Crosthwaite, 2012/10/09
- [Qemu-devel] [PATCH 04/13] qdev: allow multiple qdev_init_gpio_in() calls, Peter Crosthwaite, 2012/10/09
- [Qemu-devel] [PATCH 05/13] stellaris: Removed SSI mux, Peter Crosthwaite, 2012/10/09
- [Qemu-devel] [PATCH 06/13] hw: Added generic FIFO API., Peter Crosthwaite, 2012/10/09
- [Qemu-devel] [PATCH 07/13] m25p80: Initial implementation of SPI flash device, Peter Crosthwaite, 2012/10/09
- [Qemu-devel] [PATCH 09/13] petalogix-ml605: added SPI controller with n25q128, Peter Crosthwaite, 2012/10/09
- [Qemu-devel] [PATCH 11/13] xilinx_zynq: Added SPI controllers + flashes, Peter Crosthwaite, 2012/10/09
- [Qemu-devel] [PATCH 13/13] ssi: Add slave autoconnect helper, Peter Crosthwaite, 2012/10/09
- [Qemu-devel] [PATCH 08/13] xilinx_spi: Initial impl. of Xilinx SPI controller, Peter Crosthwaite, 2012/10/09