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[Qemu-devel] [PATCH v6 01/13] ssi: Support for multiple attached devices
From: |
Peter A. G. Crosthwaite |
Subject: |
[Qemu-devel] [PATCH v6 01/13] ssi: Support for multiple attached devices |
Date: |
Tue, 18 Sep 2012 12:10:58 +1000 |
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>
---
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] [PATCH v6 00/13] Ehnahced SSI bus support + M25P80 SPI flash + Xilinx SPI controller, Peter A. G. Crosthwaite, 2012/09/17
- [Qemu-devel] [PATCH v6 01/13] ssi: Support for multiple attached devices,
Peter A. G. Crosthwaite <=
- [Qemu-devel] [PATCH v6 02/13] ssi: Implemented CS behaviour, Peter A. G. Crosthwaite, 2012/09/17
- [Qemu-devel] [PATCH v6 03/13] ssi: Added create_slave_no_init(), Peter A. G. Crosthwaite, 2012/09/17
- [Qemu-devel] [PATCH v6 04/13] qdev: allow multiple qdev_init_gpio_in() calls, Peter A. G. Crosthwaite, 2012/09/17
- [Qemu-devel] [PATCH v6 05/13] hw/stellaris: Removed gpio_out init array., Peter A. G. Crosthwaite, 2012/09/17
- [Qemu-devel] [PATCH v6 06/13] stellaris: Removed SSI mux, Peter A. G. Crosthwaite, 2012/09/17
- [Qemu-devel] [PATCH v6 07/13] hw: Added generic FIFO API., Peter A. G. Crosthwaite, 2012/09/17
- [Qemu-devel] [PATCH v6 08/13] m25p80: Initial implementation of SPI flash device, Peter A. G. Crosthwaite, 2012/09/17