drm/nouveau/i2c: tidy up bit-bang helpers, also fixing nv50 setsda bug

Was using nv_mask, which is bad.  Reading the reg senses the current line
states, which aren't necessarily the states we're trying to drive the
lines to.

Fixed to store SCL driver state just as we already do for SDA.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

3 files changed, 94 insertions, 148 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_dp.c b/drivers/gpu/drm/nouveau/nouveau_dp.c
index 5722fd55764..07bac360245 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dp.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dp.c
@@ -578,7 +578,7 @@ nouveau_dp_link_train(struct drm_encoder *encoder, u32 datarate)
 
         dp.dcb = nv_encoder->dcb;
         dp.crtc = nv_crtc->index;
-        dp.auxch = auxch->rd;
+        dp.auxch = auxch->drive;
         dp.or = nv_encoder->or;
         dp.link = !(nv_encoder->dcb->sorconf.link & 1);
         dp.dpcd = nv_encoder->dp.dpcd;
@@ -653,7 +653,7 @@ nouveau_dp_detect(struct drm_encoder *encoder)
         if (!auxch)
                 return false;
 
-        ret = auxch_tx(dev, auxch->rd, 9, DP_DPCD_REV, dpcd, 8);
+        ret = auxch_tx(dev, auxch->drive, 9, DP_DPCD_REV, dpcd, 8);
         if (ret)
                 return false;
 
@@ -681,7 +681,7 @@ int
 nouveau_dp_auxch(struct nouveau_i2c_chan *auxch, int cmd, int addr,
                  uint8_t *data, int data_nr)
 {
-        return auxch_tx(auxch->dev, auxch->rd, cmd, addr, data, data_nr);
+        return auxch_tx(auxch->dev, auxch->drive, cmd, addr, data, data_nr);
 }
 
 static int
diff --git a/drivers/gpu/drm/nouveau/nouveau_i2c.c b/drivers/gpu/drm/nouveau/nouveau_i2c.c
index 36ffcb84f55..d0d581440d5 100644
--- a/drivers/gpu/drm/nouveau/nouveau_i2c.c
+++ b/drivers/gpu/drm/nouveau/nouveau_i2c.c
@@ -30,132 +30,83 @@
 #include "nouveau_hw.h"
 
 static void
-nv04_i2c_setscl(void *data, int state)
+i2c_drive_scl(void *data, int state)
 {
-        struct nouveau_i2c_chan *i2c = data;
-        struct drm_device *dev = i2c->dev;
-        uint8_t val;
-
-        val = (NVReadVgaCrtc(dev, 0, i2c->wr) & 0xd0) | (state ? 0x20 : 0);
-        NVWriteVgaCrtc(dev, 0, i2c->wr, val | 0x01);
-}
-
-static void
-nv04_i2c_setsda(void *data, int state)
-{
-        struct nouveau_i2c_chan *i2c = data;
-        struct drm_device *dev = i2c->dev;
-        uint8_t val;
-
-        val = (NVReadVgaCrtc(dev, 0, i2c->wr) & 0xe0) | (state ? 0x10 : 0);
-        NVWriteVgaCrtc(dev, 0, i2c->wr, val | 0x01);
-}
-
-static int
-nv04_i2c_getscl(void *data)
-{
-        struct nouveau_i2c_chan *i2c = data;
-        struct drm_device *dev = i2c->dev;
-
-        return !!(NVReadVgaCrtc(dev, 0, i2c->rd) & 4);
-}
-
-static int
-nv04_i2c_getsda(void *data)
-{
-        struct nouveau_i2c_chan *i2c = data;
-        struct drm_device *dev = i2c->dev;
-
-        return !!(NVReadVgaCrtc(dev, 0, i2c->rd) & 8);
-}
-
-static void
-nv4e_i2c_setscl(void *data, int state)
-{
-        struct nouveau_i2c_chan *i2c = data;
-        struct drm_device *dev = i2c->dev;
-        uint8_t val;
-
-        val = (nv_rd32(dev, i2c->wr) & 0xd0) | (state ? 0x20 : 0);
-        nv_wr32(dev, i2c->wr, val | 0x01);
-}
-
-static void
-nv4e_i2c_setsda(void *data, int state)
-{
-        struct nouveau_i2c_chan *i2c = data;
-        struct drm_device *dev = i2c->dev;
-        uint8_t val;
-
-        val = (nv_rd32(dev, i2c->wr) & 0xe0) | (state ? 0x10 : 0);
-        nv_wr32(dev, i2c->wr, val | 0x01);
-}
-
-static int
-nv4e_i2c_getscl(void *data)
-{
-        struct nouveau_i2c_chan *i2c = data;
-        struct drm_device *dev = i2c->dev;
-
-        return !!((nv_rd32(dev, i2c->rd) >> 16) & 4);
-}
-
-static int
-nv4e_i2c_getsda(void *data)
-{
-        struct nouveau_i2c_chan *i2c = data;
-        struct drm_device *dev = i2c->dev;
-
-        return !!((nv_rd32(dev, i2c->rd) >> 16) & 8);
-}
-
-static int
-nv50_i2c_getscl(void *data)
-{
-        struct nouveau_i2c_chan *i2c = data;
-        struct drm_device *dev = i2c->dev;
-
-        return !!(nv_rd32(dev, i2c->rd) & 1);
-}
-
-static int
-nv50_i2c_getsda(void *data)
-{
-        struct nouveau_i2c_chan *i2c = data;
-        struct drm_device *dev = i2c->dev;
-
-        return !!(nv_rd32(dev, i2c->rd) & 2);
-}
-
-static void
-nv50_i2c_setscl(void *data, int state)
-{
-        struct nouveau_i2c_chan *i2c = data;
-
-        nv_wr32(i2c->dev, i2c->wr, 4 | (i2c->data ? 2 : 0) | (state ? 1 : 0));
+        struct nouveau_i2c_chan *port = data;
+        if (port->type == 0) {
+                u8 val = NVReadVgaCrtc(port->dev, 0, port->drive);
+                if (state) val |= 0x20;
+                else       val &= 0xdf;
+                NVWriteVgaCrtc(port->dev, 0, port->drive, val | 0x01);
+        } else
+        if (port->type == 4) {
+                nv_mask(port->dev, port->drive, 0x2f, state ? 0x21 : 0x01);
+        } else
+        if (port->type == 5) {
+                if (state) port->state |= 0x01;
+                else       port->state &= 0xfe;
+                nv_wr32(port->dev, port->drive, 4 | port->state);
+        }
 }
 
 static void
-nv50_i2c_setsda(void *data, int state)
+i2c_drive_sda(void *data, int state)
 {
-        struct nouveau_i2c_chan *i2c = data;
-
-        nv_mask(i2c->dev, i2c->wr, 0x00000006, 4 | (state ? 2 : 0));
-        i2c->data = state;
+        struct nouveau_i2c_chan *port = data;
+        if (port->type == 0) {
+                u8 val = NVReadVgaCrtc(port->dev, 0, port->drive);
+                if (state) val |= 0x10;
+                else       val &= 0xef;
+                NVWriteVgaCrtc(port->dev, 0, port->drive, val | 0x01);
+        } else
+        if (port->type == 4) {
+                nv_mask(port->dev, port->drive, 0x1f, state ? 0x11 : 0x01);
+        } else
+        if (port->type == 5) {
+                if (state) port->state |= 0x02;
+                else       port->state &= 0xfd;
+                nv_wr32(port->dev, port->drive, 4 | port->state);
+        }
 }
 
 static int
-nvd0_i2c_getscl(void *data)
+i2c_sense_scl(void *data)
 {
-        struct nouveau_i2c_chan *i2c = data;
-        return !!(nv_rd32(i2c->dev, i2c->rd) & 0x10);
+        struct nouveau_i2c_chan *port = data;
+        struct drm_nouveau_private *dev_priv = port->dev->dev_private;
+        if (port->type == 0) {
+                return !!(NVReadVgaCrtc(port->dev, 0, port->sense) & 0x04);
+        } else
+        if (port->type == 4) {
+                return !!(nv_rd32(port->dev, port->sense) & 0x00040000);
+        } else
+        if (port->type == 5) {
+                if (dev_priv->card_type < NV_D0)
+                        return !!(nv_rd32(port->dev, port->sense) & 0x01);
+                else
+                        return !!(nv_rd32(port->dev, port->sense) & 0x10);
+        }
+        return 0;
 }
 
 static int
-nvd0_i2c_getsda(void *data)
+i2c_sense_sda(void *data)
 {
-        struct nouveau_i2c_chan *i2c = data;
-        return !!(nv_rd32(i2c->dev, i2c->rd) & 0x20);
+        struct nouveau_i2c_chan *port = data;
+        struct drm_nouveau_private *dev_priv = port->dev->dev_private;
+        if (port->type == 0) {
+                return !!(NVReadVgaCrtc(port->dev, 0, port->sense) & 0x08);
+        } else
+        if (port->type == 4) {
+                return !!(nv_rd32(port->dev, port->sense) & 0x00080000);
+        } else
+        if (port->type == 5) {
+                if (dev_priv->card_type < NV_D0)
+                        return !!(nv_rd32(port->dev, port->sense) & 0x02);
+                else
+                        return !!(nv_rd32(port->dev, port->sense) & 0x20);
+        }
+        return 0;
 }
 
 static const uint32_t nv50_i2c_port[] = {
@@ -258,51 +209,37 @@ nouveau_i2c_init(struct drm_device *dev)
 
                 switch (port->type) {
                 case 0: /* NV04:NV50 */
-                        port->wr = entry[0];
-                        port->rd = entry[1];
-                        port->bit.setsda = nv04_i2c_setsda;
-                        port->bit.setscl = nv04_i2c_setscl;
-                        port->bit.getsda = nv04_i2c_getsda;
-                        port->bit.getscl = nv04_i2c_getscl;
+                        port->drive = entry[0];
+                        port->sense = entry[1];
                         break;
                 case 4: /* NV4E */
-                        port->wr = 0x600800 + entry[1];
-                        port->rd = port->wr;
-                        port->bit.setsda = nv4e_i2c_setsda;
-                        port->bit.setscl = nv4e_i2c_setscl;
-                        port->bit.getsda = nv4e_i2c_getsda;
-                        port->bit.getscl = nv4e_i2c_getscl;
+                        port->drive = 0x600800 + entry[1];
+                        port->sense = port->drive;
                         break;
                 case 5: /* NV50- */
-                        port->wr = entry[0] & 0x0f;
+                        port->drive = entry[0] & 0x0f;
                         if (dev_priv->card_type < NV_D0) {
-                                if (port->wr >= ARRAY_SIZE(nv50_i2c_port))
+                                if (port->drive >= ARRAY_SIZE(nv50_i2c_port))
                                         break;
-                                port->wr = nv50_i2c_port[port->wr];
-                                port->rd = port->wr;
-                                port->bit.getsda = nv50_i2c_getsda;
-                                port->bit.getscl = nv50_i2c_getscl;
+                                port->drive = nv50_i2c_port[port->drive];
+                                port->sense = port->drive;
                         } else {
-                                port->wr = 0x00d014 + (port->wr * 0x20);
-                                port->rd = port->wr;
-                                port->bit.getsda = nvd0_i2c_getsda;
-                                port->bit.getscl = nvd0_i2c_getscl;
+                                port->drive = 0x00d014 + (port->drive * 0x20);
+                                port->sense = port->drive;
                         }
-                        port->bit.setsda = nv50_i2c_setsda;
-                        port->bit.setscl = nv50_i2c_setscl;
                         break;
                 case 6: /* NV50- DP AUX */
-                        port->wr = entry[0];
-                        port->rd = port->wr;
+                        port->drive = entry[0];
+                        port->sense = port->drive;
                         port->adapter.algo = &nouveau_dp_i2c_algo;
                         break;
                 default:
                         break;
                 }
 
-                if (!port->adapter.algo && !port->wr) {
+                if (!port->adapter.algo && !port->drive) {
                         NV_ERROR(dev, "I2C%d: type %d index %x/%x unknown\n",
-                                 i, port->type, port->wr, port->rd);
+                                 i, port->type, port->drive, port->sense);
                         kfree(port);
                         continue;
                 }
@@ -321,6 +258,15 @@ nouveau_i2c_init(struct drm_device *dev)
                         port->bit.udelay = 40;
                         port->bit.timeout = usecs_to_jiffies(5000);
                         port->bit.data = port;
+                        port->bit.setsda = i2c_drive_sda;
+                        port->bit.setscl = i2c_drive_scl;
+                        port->bit.getsda = i2c_sense_sda;
+                        port->bit.getscl = i2c_sense_scl;
+
+                        i2c_drive_scl(port, 0);
+                        i2c_drive_sda(port, 1);
+                        i2c_drive_scl(port, 1);
+
                         ret = i2c_bit_add_bus(&port->adapter);
                 } else {
                         port->adapter.algo = &nouveau_dp_i2c_algo;
@@ -381,7 +327,7 @@ nouveau_i2c_find(struct drm_device *dev, u8 index)
         if (dev_priv->card_type >= NV_50 && (port->dcb & 0x00000100)) {
                 u32 reg = 0x00e500, val;
                 if (port->type == 6) {
-                        reg += port->rd * 0x50;
+                        reg += port->drive * 0x50;
                         val  = 0x2002;
                 } else {
                         reg += ((port->dcb & 0x1e00) >> 9) * 0x50;
diff --git a/drivers/gpu/drm/nouveau/nouveau_i2c.h b/drivers/gpu/drm/nouveau/nouveau_i2c.h
index cf5f67d51fb..1d083893a4d 100644
--- a/drivers/gpu/drm/nouveau/nouveau_i2c.h
+++ b/drivers/gpu/drm/nouveau/nouveau_i2c.h
@@ -39,9 +39,9 @@ struct nouveau_i2c_chan {
         u8  index;
         u8  type;
         u32 dcb;
-        unsigned rd;
-        unsigned wr;
-        unsigned data;
+        u32 drive;
+        u32 sense;
+        u32 state;
 };
 
 int  nouveau_i2c_init(struct drm_device *);