On 6 August 2012 03:16, Peter A. G. Crosthwaite
<peter.crosthwa...@petalogix.com> wrote:
> Added default CS behaviour for SSI slaves. SSI devices can set a property
> to enable CS behaviour which will create a GPIO on the device which is the
> CS. Tristating of the bus on SSI transfers is implemented.
>
> Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwa...@petalogix.com>
> ---
> hw/ssd0323.c | 6 ++++++
> hw/ssi-sd.c | 6 ++++++
> hw/ssi.c | 39 ++++++++++++++++++++++++++++++++++++++-
> hw/ssi.h | 27 +++++++++++++++++++++++++++
> 4 files changed, 77 insertions(+), 1 deletions(-)
>
> diff --git a/hw/ssd0323.c b/hw/ssd0323.c
> index b0b2e94..db16d20 100644
> --- a/hw/ssd0323.c
> +++ b/hw/ssd0323.c
> @@ -277,6 +277,7 @@ static void ssd0323_cd(void *opaque, int n, int level)
>
> static void ssd0323_save(QEMUFile *f, void *opaque)
> {
> + SSISlave *ss = SSI_SLAVE(opaque);
> ssd0323_state *s = (ssd0323_state *)opaque;
> int i;
>
> @@ -294,10 +295,13 @@ static void ssd0323_save(QEMUFile *f, void *opaque)
> qemu_put_be32(f, s->remap);
> qemu_put_be32(f, s->mode);
> qemu_put_buffer(f, s->framebuffer, sizeof(s->framebuffer));
> +
> + qemu_put_be32(f, ss->cs ? 1 : 0);
You don't need this ?: -- the standard bool-to-integer casting
rules will do it for you. Also, stray blank line, and you're
changing save/load format so you need to update a version number
somewhere.
> }
>
> static int ssd0323_load(QEMUFile *f, void *opaque, int version_id)
> {
> + SSISlave *ss = SSI_SLAVE(opaque);
> ssd0323_state *s = (ssd0323_state *)opaque;
> int i;
>
> @@ -319,6 +323,8 @@ static int ssd0323_load(QEMUFile *f, void *opaque, int
> version_id)
> s->mode = qemu_get_be32(f);
> qemu_get_buffer(f, s->framebuffer, sizeof(s->framebuffer));
>
> + ss->cs = !!qemu_get_be32(f);
!! unnecessary here.
Same comments as here and the one above apply to the other devices
below.
> +
> return 0;
> }
>
> diff --git a/hw/ssi-sd.c b/hw/ssi-sd.c
> index b519bdb..6fd9ab9 100644
> --- a/hw/ssi-sd.c
> +++ b/hw/ssi-sd.c
> @@ -197,6 +197,7 @@ static uint32_t ssi_sd_transfer(SSISlave *dev, uint32_t
> val)
>
> static void ssi_sd_save(QEMUFile *f, void *opaque)
> {
> + SSISlave *ss = SSI_SLAVE(opaque);
> ssi_sd_state *s = (ssi_sd_state *)opaque;
> int i;
>
> @@ -209,10 +210,13 @@ static void ssi_sd_save(QEMUFile *f, void *opaque)
> qemu_put_be32(f, s->arglen);
> qemu_put_be32(f, s->response_pos);
> qemu_put_be32(f, s->stopping);
> +
> + qemu_put_be32(f, ss->cs ? 1 : 0);
> }
>
> static int ssi_sd_load(QEMUFile *f, void *opaque, int version_id)
> {
> + SSISlave *ss = SSI_SLAVE(opaque);
> ssi_sd_state *s = (ssi_sd_state *)opaque;
> int i;
>
> @@ -229,6 +233,8 @@ static int ssi_sd_load(QEMUFile *f, void *opaque, int
> version_id)
> s->response_pos = qemu_get_be32(f);
> s->stopping = qemu_get_be32(f);
>
> + ss->cs = !!qemu_get_be32(f);
> +
> return 0;
> }
>
> diff --git a/hw/ssi.c b/hw/ssi.c
> index 2db88fc..2e4f2fe 100644
> --- a/hw/ssi.c
> +++ b/hw/ssi.c
> @@ -27,19 +27,55 @@ static const TypeInfo ssi_bus_info = {
> .instance_size = sizeof(SSIBus),
> };
>
> +static void ssi_cs_default(void *opaque, int n, int level)
> +{
> + SSISlave *s = SSI_SLAVE(opaque);
> + bool cs = !!level;
> + assert(n == 0);
> + if (s->cs != cs) {
> + SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
> + if (ssc->set_cs) {
> + ssc->set_cs(s, cs);
> + }
> + }
> + s->cs = cs;
> +}
> +
> +static uint32_t ssi_transfer_raw_default(SSISlave *dev, uint32_t val)
> +{
> + SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(dev);
> +
> + if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) ||
> + (!dev->cs && ssc->cs_polarity == SSI_CS_LOW) ||
> + ssc->cs_polarity == SSI_CS_NONE) {
> + return ssc->transfer(dev, val);
> + }
> + return 0;
> +}
> +
> static int ssi_slave_init(DeviceState *dev)
> {
> SSISlave *s = SSI_SLAVE(dev);
> SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
>
> + if (ssc->transfer_raw == ssi_transfer_raw_default &&
> + ssc->cs_polarity != SSI_CS_NONE) {
> + qdev_init_gpio_in(&s->qdev, ssi_cs_default, 1);
> + }
> +
> return ssc->init(s);
> }
>
> static void ssi_slave_class_init(ObjectClass *klass, void *data)
> {
> + SSISlaveClass *ssc = SSI_SLAVE_CLASS(klass);
> DeviceClass *dc = DEVICE_CLASS(klass);
> +
> dc->init = ssi_slave_init;
> dc->bus_type = TYPE_SSI_BUS;
> + if (!ssc->transfer_raw) {
> + ssc->transfer_raw = ssi_transfer_raw_default;
> + }
> }
>
> static TypeInfo ssi_slave_info = {
> @@ -74,7 +110,7 @@ uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
> QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
> SSISlave *slave = SSI_SLAVE(kid->child);
> ssc = SSI_SLAVE_GET_CLASS(slave);
> - r |= ssc->transfer(slave, val);
> + r |= ssc->transfer_raw(slave, val);
> }
>
> return r;
> @@ -86,6 +122,7 @@ const VMStateDescription vmstate_ssi_slave = {
> .minimum_version_id = 1,
> .minimum_version_id_old = 1,
> .fields = (VMStateField[]) {
> + VMSTATE_BOOL(cs, SSISlave),
New field -> must bump version. You could probably avoid this by
rearranging things so this field is in the vmstate from the start
rather than added in a subsequent patch.
> VMSTATE_END_OF_LIST()
> }
> };
> diff --git a/hw/ssi.h b/hw/ssi.h
> index 975f9fb..5b69a3b 100644
> --- a/hw/ssi.h
> +++ b/hw/ssi.h
> @@ -23,16 +23,43 @@ typedef struct SSISlave SSISlave;
> #define SSI_SLAVE_GET_CLASS(obj) \
> OBJECT_GET_CLASS(SSISlaveClass, (obj), TYPE_SSI_SLAVE)
>
> +typedef enum {
> + SSI_CS_NONE = 0,
> + SSI_CS_LOW,
> + SSI_CS_HIGH,
> +} SSICSMode;
> +
> /* Slave devices. */
> typedef struct SSISlaveClass {
> DeviceClass parent_class;
>
> int (*init)(SSISlave *dev);
> +
> + /* if you have standard or no CS behaviour, just override transfer.
> + * This is called when the device cs is active (true by default).
> + */
> uint32_t (*transfer)(SSISlave *dev, uint32_t val);
> + /* called when the CS line changes. Optional, devices only need to
> implement
> + * this if they have side effects assoicated with the cs line (beyond
"associated"
> + * tristating the txrx lines).
> + */
> + int (*set_cs)(SSISlave *dev, bool select);
> + /* define whether or not CS exists and is active low/high */
> + SSICSMode cs_polarity;
> +
> + /* if you have non-standard CS behvaiour override this to take control
"behaviour" (and below)
> + * of the CS behvaiour at the device level. transfer, set_cs, and
> + * cs_polarity are unused if this is overwritten. Transfer_raw, will
spurious comma
> + * always be called for the device for every txrx access the to parent
> bus
"to the"
> + */
> + uint32_t (*transfer_raw)(SSISlave *dev, uint32_t val);
> } SSISlaveClass;
>
> struct SSISlave {
> DeviceState qdev;
> +
> + /* Chip select state */
> + bool cs;
> };
>
> #define SSI_SLAVE_FROM_QDEV(dev) DO_UPCAST(SSISlave, qdev, dev)
> --
> 1.7.0.4
>
-- PMM
