drm/msm: add mdp5/apq8x74

Add support for the new MDP5 display controller block.  The mapping
between parts of the display controller and KMS is:

  plane   -> PIPE{RGBn,VIGn}             \
  crtc    -> LM (layer mixer)            |-> MDP "device"
  encoder -> INTF                        /
  connector -> HDMI/DSI/eDP/etc          --> other device(s)

Unlike MDP4, it appears we can get by with a single encoder, rather
than needing a different implementation for DTV, DSI, etc.  (Ie. the
register interface is same, just different bases.)

Also unlike MDP4, all the IRQs for other blocks (HDMI, DSI, etc) are
routed through MDP.

And finally, MDP5 has this "Shared Memory Pool" (called "SMP"), from
which blocks need to be allocated to the active pipes based on fetch
stride.

Signed-off-by: Rob Clark <robdclark@gmail.com>

1 files changed, 173 insertions, 0 deletions

diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c
new file mode 100644
index 000000000000..2d0236b963a6
--- /dev/null
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2013 Red Hat
+ * Author: Rob Clark <robdclark@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "mdp5_kms.h"
+#include "mdp5_smp.h"
+
+
+/* SMP - Shared Memory Pool
+ *
+ * These are shared between all the clients, where each plane in a
+ * scanout buffer is a SMP client.  Ie. scanout of 3 plane I420 on
+ * pipe VIG0 => 3 clients: VIG0_Y, VIG0_CB, VIG0_CR.
+ *
+ * Based on the size of the attached scanout buffer, a certain # of
+ * blocks must be allocated to that client out of the shared pool.
+ *
+ * For each block, it can be either free, or pending/in-use by a
+ * client.  The updates happen in three steps:
+ *
+ *  1) mdp5_smp_request():
+ *     When plane scanout is setup, calculate required number of
+ *     blocks needed per client, and request.  Blocks not inuse or
+ *     pending by any other client are added to client's pending
+ *     set.
+ *
+ *  2) mdp5_smp_configure():
+ *     As hw is programmed, before FLUSH, MDP5_SMP_ALLOC registers
+ *     are configured for the union(pending, inuse)
+ *
+ *  3) mdp5_smp_commit():
+ *     After next vblank, copy pending -> inuse.  Optionally update
+ *     MDP5_SMP_ALLOC registers if there are newly unused blocks
+ *
+ * On the next vblank after changes have been committed to hw, the
+ * client's pending blocks become it's in-use blocks (and no-longer
+ * in-use blocks become available to other clients).
+ *
+ * btw, hurray for confusing overloaded acronyms!  :-/
+ *
+ * NOTE: for atomic modeset/pageflip NONBLOCK operations, step #1
+ * should happen at (or before)? atomic->check().  And we'd need
+ * an API to discard previous requests if update is aborted or
+ * (test-only).
+ *
+ * TODO would perhaps be nice to have debugfs to dump out kernel
+ * inuse and pending state of all clients..
+ */
+
+static DEFINE_SPINLOCK(smp_lock);
+
+
+/* step #1: update # of blocks pending for the client: */
+int mdp5_smp_request(struct mdp5_kms *mdp5_kms,
+		enum mdp5_client_id cid, int nblks)
+{
+	struct mdp5_client_smp_state *ps = &mdp5_kms->smp_client_state[cid];
+	int i, ret, avail, cur_nblks, cnt = mdp5_kms->smp_blk_cnt;
+	unsigned long flags;
+
+	spin_lock_irqsave(&smp_lock, flags);
+
+	avail = cnt - bitmap_weight(mdp5_kms->smp_state, cnt);
+	if (nblks > avail) {
+		ret = -ENOSPC;
+		goto fail;
+	}
+
+	cur_nblks = bitmap_weight(ps->pending, cnt);
+	if (nblks > cur_nblks) {
+		/* grow the existing pending reservation: */
+		for (i = cur_nblks; i < nblks; i++) {
+			int blk = find_first_zero_bit(mdp5_kms->smp_state, cnt);
+			set_bit(blk, ps->pending);
+			set_bit(blk, mdp5_kms->smp_state);
+		}
+	} else {
+		/* shrink the existing pending reservation: */
+		for (i = cur_nblks; i > nblks; i--) {
+			int blk = find_first_bit(ps->pending, cnt);
+			clear_bit(blk, ps->pending);
+			/* don't clear in global smp_state until _commit() */
+		}
+	}
+
+fail:
+	spin_unlock_irqrestore(&smp_lock, flags);
+	return 0;
+}
+
+static void update_smp_state(struct mdp5_kms *mdp5_kms,
+		enum mdp5_client_id cid, mdp5_smp_state_t *assigned)
+{
+	int cnt = mdp5_kms->smp_blk_cnt;
+	uint32_t blk, val;
+
+	for_each_set_bit(blk, *assigned, cnt) {
+		int idx = blk / 3;
+		int fld = blk % 3;
+
+		val = mdp5_read(mdp5_kms, REG_MDP5_SMP_ALLOC_W_REG(idx));
+
+		switch (fld) {
+		case 0:
+			val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT0__MASK;
+			val |= MDP5_SMP_ALLOC_W_REG_CLIENT0(cid);
+			break;
+		case 1:
+			val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT1__MASK;
+			val |= MDP5_SMP_ALLOC_W_REG_CLIENT1(cid);
+			break;
+		case 2:
+			val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT2__MASK;
+			val |= MDP5_SMP_ALLOC_W_REG_CLIENT2(cid);
+			break;
+		}
+
+		mdp5_write(mdp5_kms, REG_MDP5_SMP_ALLOC_W_REG(idx), val);
+		mdp5_write(mdp5_kms, REG_MDP5_SMP_ALLOC_R_REG(idx), val);
+	}
+}
+
+/* step #2: configure hw for union(pending, inuse): */
+void mdp5_smp_configure(struct mdp5_kms *mdp5_kms, enum mdp5_client_id cid)
+{
+	struct mdp5_client_smp_state *ps = &mdp5_kms->smp_client_state[cid];
+	int cnt = mdp5_kms->smp_blk_cnt;
+	mdp5_smp_state_t assigned;
+
+	bitmap_or(assigned, ps->inuse, ps->pending, cnt);
+	update_smp_state(mdp5_kms, cid, &assigned);
+}
+
+/* step #3: after vblank, copy pending -> inuse: */
+void mdp5_smp_commit(struct mdp5_kms *mdp5_kms, enum mdp5_client_id cid)
+{
+	struct mdp5_client_smp_state *ps = &mdp5_kms->smp_client_state[cid];
+	int cnt = mdp5_kms->smp_blk_cnt;
+	mdp5_smp_state_t released;
+
+	/*
+	 * Figure out if there are any blocks we where previously
+	 * using, which can be released and made available to other
+	 * clients:
+	 */
+	if (bitmap_andnot(released, ps->inuse, ps->pending, cnt)) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&smp_lock, flags);
+		/* clear released blocks: */
+		bitmap_andnot(mdp5_kms->smp_state, mdp5_kms->smp_state,
+				released, cnt);
+		spin_unlock_irqrestore(&smp_lock, flags);
+
+		update_smp_state(mdp5_kms, CID_UNUSED, &released);
+	}
+
+	bitmap_copy(ps->inuse, ps->pending, cnt);
+}