USB DMA was installed on "normal DMAC" when SH7724 or older SuperH,
but the "USB-DMAC" was prepared on recent SuperH.
These 2 DMAC have a little bit different behavior.

This patch add DMAEngine code for "normal DMAC",
but it is still using PIO fifo.
The DMA fifo will be formally supported in the future.

You can enable DMA fifo by local fixup
usbhs_fifo_pio_push_handler -> usbhs_fifo_dma_push_handler
usbhs_fifo_pio_pop_handler  -> usbhs_fifo_dma_pop_handler
on usbhsg_ep_enable.

This DMAEngine was tested by g_file_storage on SH7724 Ecovec board
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch tidyup PIO packet handler name.
This is a preparation for DMAEngine support
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

packet transfer timing are controlled in mod_gadget on current renesas_usbhs,
and this style will be imitated on mod_host.
But it need not be managed with host/gadget if it is general transfer.
By this patch, the packet transfer timing is managed in fifo.c
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

renesas_usbhs has CFIFO which is for PIO transfer,
and D0FIFO/D1FIFO which are for DMA transfer.
The pipe selects one of these fifo when it send/recv data.
But fifo must not be selected to different pipe in same time.
This patch add pipe/fifo link for each other,
and fifo is not selected by another pipe until it is unselected.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

renesas_usbhs has CFIFO/D0FIFO/D1FIFO.
But current renesas_usbhs is using CFIFO (for PIO) only for now.
The fifo selection method is needed for DMAEngine support.
This is a preparation for DMAEngine support
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

spin lock was very effective while doing 1 packet send/recv on
current renesas_usbhs driver.
But this lock is enough only
 - modify packet/pipe link
 - modify interrpt mask
 - modify fifo access
This patch shrink spin lock area
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

On current driver, overall data transfer method was implemented in fifo.c,
but its interrupt which is member of packet queue control
was still in mod_gadget.c.
This patch move it into fifo.c.
By this patch, the packet/fifo control is independent from mod_gadget.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

On current driver, main data transfer function was implemented in fifo.c,
but the overall controlling was implementing in mod_gadget.c.
This style is not useful to support host and DMAEngine in the future.

But the interrupt for data transfer cannot separate easily for now,
because it is deeply related to mod_gadget.

This patch move the overall data transfer method
into fifo.c except interrupt.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Current renesas_usbhs driver is controlling packet queue on mod_gadget.c.
But it has relationship with pipe/fifo, not host/gadget.
So, controlling USB packet queue in pipe.c/fifo.c is
more convenient than in mod_gadget.c.
This patch modify it.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

DMAEngine will be supported to this driver in the future.
Then, both PIO and DMA data transfer method should be supported.
But, the transfer function can returns the result immediately
in PIO version, but it can't in DMA version.
This patch divides data transfer functions into top/bottom half
in preparation for DMAEngine support.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Current renesas_usbhs has PIO data transfer mode which controls CFIFO.
And it was implemented in pipe.c.
But, fifo control method needs more flexible implementation
to support DMAEngine.
This patch create fifo.c, and it became independent from pipe.c.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>